20101034 Ver 1_Stormwater Info_20101215

U
EcoEngineering
A division of The John R. McAdams Company, Inc.
DEC 1 6 2010
TOWN HALL COMMONS
MOMS VILLE, NORTH CAROLINA
Final Design of Stormwater Management Facilties
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PLT-10000
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?Q
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December 2010
Jeremy V. Finch, PE
Project Manager
Research Triangle Park, NC
Post Office Box 14005
Research Triangle Park,
North Carolina 27709
2905 idian Parkway
G th Carolina 27713
80. 46
919-287-4262
919-361-2269 Fax
Brandon R. Finch, PE
Sr. Project Manager
www.ecoengr.com i Design Services Focused On Client Success
TOWN HALL COMMONS
• Final Design of Stormwater Management Facilities
General Description & Background
Located just west of Town Hall Drive, between McCrimmon Parkway and Airport Road in
Morrisville, North Carolina is the proposed residential development currently known as Town
Hall Commons. Proposed development on this approximately 12.83-acre site is the construction
of 40 single-family residential lots, along with the associated streets, sidewalks, utility
infrastructure/improvements, and the required stormwater management facilities. In the post-
development condition, the site will be greater than 24% impervious, thus classifying it as a high-
density development. This report addresses the impact of increased stormwater runoff due to the
proposed development. Included within this report are the. Anal design calculations for the
proposed stormwater management facilities that will be used to mitigate the impacts.
The proposed development drains to an unnamed tributary to Crabtree Creek, which is located
within the Neuse River basin, and is outside of a watershed protection district. The proposed
development will be subject to the Town of Morrisville Stormwater Runoff Management Policy.
Per Town of Morrisville regulations, stormwater management on this site shall address two
primary issues: (1) water quantity management and (2) water quality management.
1. According to Town of Morrisville Code section 7.303.1 (based upon Phase H Stormwater
Model Ordinance for NQ, projects shall implement stormwater control measures that
control and treat the difference in Stormwater runoff volume leaving the project site
between the pre- and post-development conditions for, at a minimum, the ]-year, 24-hour
storm. Runoff volume drativdown time shall be a minimum of 24 hours, but not more than
• 120. hours. Also, the Town of Morrisville requires peak flowrate detention of the 10 year,
24-hour storm-event.
2. According to Town of Morrisville Code section 7.303.2 (based upon Phase II Stormwater
Model Ordinance.for NC), all structural stormwater treatment systems used to meet the
requirements of the program shall be designed to have a minimum of 85% average
annual removal, for total suspended solids.
This report contains final design calculations detailing the expected stormwater impacts as a
result of the proposed development, along with the final design calculations for the proposed
stormwater best management practices that will be used to mitigate the impacts. Please refer to
the appropriate sections of this report for additional information.
Calculation Methodology
? "New" rainfall data for the Morrisville, NC region. is from NOAA Atlas 14, with a
partial duration series assumption. The rainfall depths were entered into Pondpack
based upon the SCS Type II storm distribution. The 1-year/24-hour rainfall depth is
2.84 inches, the 2-Year/24-hour rainfall depth is 3.43 inches, the 10-Year./24-hour
rainfall depth is 4.96 inches, and the 100=year/24-hour rainfall depth is 7.30 inches.
All of these storms were modeled within Pondpack. Please reference the rainfall data
section within this report for additional information.
Using maps contained within the Wake County Soil Surveys, the on- and off-site soils
were determined to range from hydrologic soil group (HSG) `B' soils to HSG `D'
• soils. Since the method chosen to compute both pre- and post-development peak flow
rates and runoff volumes is dependent upon the soil type, care was taken when
selecting the appropriate Soil Conservation Service Curve Number (SCS CN).
Within each sub-basin,, an approximate proportion of each soil group was determined
• using NRCS Soil Survey Maps. Once an approximate proportion was determined, a.
composite SCS CN was computed for each cover condition. For example, the pre-
development soil composition of Sub-basin #6 consists of approximately 6.3% HSG
`B' soils, 2.6% HSG `C' soils, and 91.1 % HSG `D' soils. Therefore, for the open area
cover condition, the composite SCS CN is computed as follows (assuming good
condition):
Composite Open SCS CN = (0.063 *61) + (0.026*74)+(0.911 * 80) = 79
This type of calculation was done for each of the studied sub-basins in an effort to
accurately account for the difference in runoff between HSG `B', `C', and `D' soils.
y A composite SCS Curve Number was calculated for both the pre- and post-
development condition for each subbasin using SCS curve numbers and land cover
conditions. Land cover. conditions for the pre-development condition were taken from
a combination of Google Earth Aerial Photography, field survey information, and
from the approved design by Priest Craven & Associates, Inc. Land cover conditions
for the post-development condition were taken from the proposed development plan
and offsite design information from both Withers & Ravenel and Priest Craven &
Associates, Inc.
The time of concentration was calculated using SCS TR-55 (Segmental Approach,
1986). The Tc flow path was divided into three segments: overland flow,
concentrated flow, and channel flow. The travel time was then computed for each
seginent, from which the overall time of concentration was determined by taking the
sum of each segmental time. For the overland flow segment, the Town of Morrisville
normally requires a woods w/ dense underbrush assumption (n=0.80) for the
Manning's n value of the overland flow segment. However, per the site photographs
included in the pre-development hydrologic calculations section of this report of
representative pre-development onsite wooded area, a woods w/ light underbrush
assumption (n=0.40) is validated for use in the hydrologic calculations for a few of
the subbasins. For the channel flow segment of the time of concentration calculations,
a channel dimension that generated an average bankfull velocity of approximately 5
feet per second was assumed. This assumption is based upon a study by the US
Geological Survey where of 2,950 natural river channel velocity measurements, the
median average velocity was 4.11 feet per second, with the mean average velocity
being 4.84 feet per second.
The post-development time of concentration to the proposed stormwater management
facilities and trivially small subbasins was assumed to be 5 minutes.
? The on- and off-site topography used in the hydrologic/hydraulic analysis is from two
different sources. They are as follows:
The existing on-site topography used in all pre- and post-development
hydrologic calculations, including preparation of the preliminary stormwater
management facility grading plans, is from a field survey of the site performed
by The John R. McAdams Company, Inc.
The existing off-site topography used in all pre- and post-development
hydrologic calculations is from Wake County GIS information
•
The existing topography for the offsite existing wet pond BMP facility located
• in the.a acent-Twin Lakes development is from asbuilt information provided
to The Jim R. McAdams Company, Inc. by Withers and Ravenel. This asbuilt
topography was used to prepare the analysis of the existing offsite Twin Lakes
wet pond BMP to determine its' adequacy to accept drainage from the
proposed development.
Please refer to the pre- and post-development watershed maps for more information.
? Pondpack Version 10.0, by Haestad Methods, was used in determining the pre- &
post-development peak flow rates for the 1-, 2-, 10-, 25-, 50-, and 100-year storm
events, as well as for preliminary routing calculations of the proposed stormwater
management facilties.
? The stage-discharge rating curves, stage-storage rating curves, and stage-storage
functions for the proposed stormwater management facilities were generated in
Pondpack. The stage-storage rating curve utilized for the existing wet pond BMP
located in the adjacent Twin Lakes development was extracted from asbuilt field
survey information provided to The John R. McAdams Company, Inc. by Withers &
Ravenel. The stage-discharge rating curve for the existing wet pond BMP located in
the adjacent Twin Lakes development was also obtained from asbuilt field survey
information provided to The John R. McAdams Company, Inc. by Withers &
Ravenel. Please refer to the copy of the previously approved Twin Lakes design report
and asbuilt field survey information for the offsite Twin Lakes wet pond BMP
included in this report for more information.
. ? Final water quality sizing calculations for the proposed onsite stormwater wetlands
were performed in accordance with the N.C. Stormwater Best Management Practices
manual (NCDENR July 2007). The normal pool surface area of each wetland facility
was sized using the runoff volume computed using the Simple Method and a
maximum ponding depth of 12-inches.
Per the N.C. Stormwater Best Management Practices manual (NCDENR July 2007),
the normal pool elevation of each wetland facility must be sited based upon 1 of the
following criteria:
(1) If the wetland intersects the shallow groundwater table, groundwater may be
utilized to maintain the PPE at the design elevation. In this case, DWQ requires
that the PPE be no more than six (6) inches above or below the SHWT. DWQ
may require installation of an impermeable liner beneath deep pools depending on
soil permeability.
(2) If the SHWT is not present near ground surface, and the stormwater wetland
is to be perched above the water table, or located in highly permeable soils like
gravelly sands or fractured bedrock, DWQ requires installation of an impermeable
soil/clay/geomembrane liner with an infiltration rate of less than 0.01 in/hr
beneath the entire bottom of deep pools and shallow water areas to sustain the
permanent pool of water.
A site visit was performed by a professional wetland scientist to determine the
location of the seasonal high water table for the proposed stormwater wetland
facilities. Included in the soils section of this report is an exhibit showing the
• approximate locations of where the seasonal high water table determinations were
made, along with a summary of approximate seasonal high water table determinations
for each facility. Based upon the seasonal high water table determinations performed,
the proposed normal pool elevation of each facility meets criteria #1 above for
maintaining the permanent pool elevation and preventing the facilities from drying
out.
y The analysis of the existing offsite wet pond BMP -located in the ajdacent Twin Lakes
development was performed based upon the calculations obtained from the approved
design report by Withers and Ravenel (sealed by Hunter Freeman, PE on 6/9/2006).
The approved design report was based upon the. N.C. Stormwater Best Management
Practices April 1999 BMP manual. To remain consistent with the approved design
report, the asbuilt normal pool surface area and asbuilt water quality storage provided
(ie. volume between the asbuilt normal pool and asbuilt riser crest elevation) was
compared to the computed required normal pool surface area and computed required
water quality storage shown in the approved design report. Also important to note is
that the approved design hydrology was utilized for the purposes of the asbuilt
analysis of the existing wet pond BMP. Based upon this analysis, both the asbuilt
normal pool surface area and asbuilt water quality storage provided by the existing
wet pond BMP exceed the computed required nofkt 'l°pool surface area and required
water quality storage shown in the approved design report. Therefore, since the
drainage area and impervious area from the proposed Town Hall Commons
development is less than the what is accounted for from offsite area in the approved
design report for the existing Twin Lakes wet pond BMP, all applicable Town of
Morrisville water quantity/water quality regulations are satisfied by the existing
offsite Twin Lakes wet pond BMP for subbasin #3 of the proposed. Town Hall
Commons development.
• Nitrogen Export Loading rates were calculated using NCDENR Methodology:
Method A - Quantifying TN Export from Residential/Industrial/Commercial
Developments when footprints of all impervious surfaces are shown. By summing the
total nitrogen export for each sub-basin and bypass areas, the total nitrogen export for
the proposed site was calculated. Please see the included nitrogen calculations for
details.
A riprap plunge pool / level spreader outlet is provided at the principal spillway outlet
of the proposed stormwater management facilities to prevent erosion and scour in the
downstream areas. These systems will be constructed using rip rap, underlain with a
woven geotextile filter fabric, along with permanent turf matting for the level
spreader. The filter fabric is used to minimize the loss of soil particles beneath the rip
rap apron, while the permanent turf matting is used to prevent erosion/scour of the
level spreader. These systems are sized for the 10-year storm event using the NYDOT
method, and are permanent features of the outlet structures.
Existing Gardens at Townhall Commons Wetland (Offsite) Removal Discussion
Bordering the proposed development to the east is the existing residential development known as
The Gardens at Townhall Commons. Constructed as part of this development to meet local/state
water quantity/quality requirements was a stormwater wetland facility. Proposed as part of the
development of Town Hall Commons is the removal of the existing stormwater wetland within
The Gardens at Townhall Commons and the construction of a new stormwater wetland. facility
that will be designed to provide water quantity/quality for the receiving drainage area from both
developments. To avoid creating a new discharge point into the Neuse Buffer, the proposed
• wetland #2 and #3 outfall pipe will coincide with the existing Gardens at Townhall Commons
wetland outlet pipe.
• Stormwater Wetland #2 & #3 Pre Post Hydrologic Analysis Discussion
As mentioned above, to avoid creating a new discharge point into the Neuse Buffer, the proposed
outlet pipe from stormwater wetland # 2 and #3 will combine and overlap with the existing
Gardens at Townhall Commons wetland outlet pipe location. As a result, the approved pre-
development hydrology from The Gardens at Townhall Commons stormwater wetland as shown
on the asbuilt plans by Priest Craven & Associates, Inc. (sealed by Thomas Craven, PE on
9/26/2008) was utilized in conjunction with "new" rainfall data to determine the "pre-
development" peak flowrate for the purposes of the pre-post study for the proposed Townhall
Commons development. Using the approved pre-development hydrology input data from the
approved design by Priest Craven & Associates, Inc., pre-development peak flowrates were
"recomputed" based upon the "new" rainfall data (le. same rainfall data used in the post-
development calculations). The "recomputed" pre-development peak flowrates were used as the
basis to compare the post-development peak flowrates from the proposed wetland 92 and 93
outfall to ensure the pre-development condition as met by the existing Gardens at Townhall
Commons stormwater wetland outfall is maintained. As shown in the summary of results, the
post-development peak outflow from the combined outlet pipe for stormwater wetland #2 and #3
was maintained at or below the "recomputed" pre-development peak flowrates (based upon
"new" rainfall data) based upon the pre-development hydrology shown in the approved Priest
Craven & Associates design calculations.
Diffuse Flow Requirement Discussion
Per Section 5 of NC Administrative Code 15A NCAC 02B .0233 Neuse River Basin Protection
and Maintenance of Existing Riparian Buffers, diffuse flow of runoff shall be maintained in the
riparian buffer by dispersing concentrated flow and reestablishing vegetation. Concentrated
• runoff from new ditches and manmade conveyances shall be converted to diffuse flow before the
runoff enters the Zone 2 of the riparian buffer. Periodic corrective action to restore diffuse flow
shall he taken if necessary to impede the formation of erosion gullies. Since the proposed Town
Hall Commons project is located within the N'euse River Basin, it is subject to the diffuse flow
requirements.
To address this requirement, stormwater wetlands are proposed for water quality treatment,
which per Chapter 8 - "Level Spreader and Vegetative Filter Strip" of the NC DWQ BMP
Manual, if instead of diffuse flow a BMP that removes at least 30% TN and 30% TP is provided,
the overflow may discharge through the buffer directly into the stream channel with a buffer
authorization from the DWQ 401 program. Therefore, in lieu of providing diffuse flow,
stormwater wetlands are proposed, which are credited with removing 40%o TN and 40% TP. The
larger storms (i.e. greater than the water quality volume events) will discharge thru the "principal
spillway system" and will outlet directly into the existing stream channels. As a result, both a
buffer authorization and approval of the diffuse flow plan from the DWQ 401 program is
required before construction of this systems may occur.
.0iscussion of Rescrlts
As shown in the Summary of Results table, the proposed stormwater management facilities have
sufficient volume to achieve both 1-year storm detention (peak & difference in pre-post volume)
and 10-year storm detention (peak flowrate). Per the 2007 NCDENR Stormwater BMP Manual,
the proposed stormwater management facilities as designed receive credit for achieving 85%
removal of the total suspended solids from the incoming stormwater runoff. Conclusively, all
applicable Town of Morrisville stormwater regulations have been satisfied by the proposed
• stormwater management facilities. A more detailed summary of each subbasin analyzed in this
report and how each is affected from pre- to post-development in regards to area, landuse, and
time of concentration is given below:
• Subbasin 1
This subbasin is located along the northern property boundary, and drains off to the northwest. In
the pre-development condition, this 1.40-acre subbasin is entirely wooded (SCS CN = 77), with a
pre-development time of concentration of 25.46 minutes. In the post-development condition, the
subbasin area decreases to 0.73-acres due to the proposed grading plan redirecting drainage away
from this subbasin. This subbasin. is almost completely open space with a small pocket of
impervious, and as a result, the post-development SCS CN is 80, with the time of concentration
assumed to be 5.00 minutes due to small size of the subbasin. As can be seen in the Summary of
Results, the 10-year post-development peak flow rate within this subbasin was maintained at or
below pre-development levels. However, there is a slight increase during the l-year storm, which
according to the Town of Morrisville Policy memo, does not require a downstream analysis
unless the increase in discharge is greater than 10%.
Subbasin 2
This subbasin is located in the northeast corner of the site, and drains to the northeast. In the pre-
development condition, this 1.75-acre subbasin is entirely wooded (SCS CN = 76), with a pre-
development time of concentration of 52.43 minutes. In the post-development condition, the
subbasin area increases to 3.41-acres (includes bypass area), and there is a stormwater
management facility (stormwater wetland #1) proposed in this subbasin. This subbasin contains
mostly proposed development, and as a result, the post-development SCS CN to the wetland is
90 and the SCS CN to the bypass area is 76, with the the time of concentration for both areas
assumed to be 5 minutes due to the amount of impervious area and piped storm drainage system.
As can be seen in the Summary of Results, the proposed stormwater wetland facility will provide
detention such that the pre-development peak flow rates are no greater than post-development
peak flow rates in the I - and 10-year design storm events.
Subbasin 3
This subbasin is located just south of subbasin #1, and drains off to the southwest. In the pre-
development condition, this 2.07-acre subbasin is entirely wooded (SCS CN = 77), with a pre-
development time of concentration of 55.00 minutes. In the post-development condition, the
subbasin area decreases to 0.95-acres due to the proposed grading plan redirecting drainage away
from this subbasin. This subbasin contains a mix of impervious area and open space, and as a
result, the post-development SCS CN is 83, with the time of concentration assumed to be 5
minutes due to the small size of the subbasin. As can be seen in the Summary of Results, the
post-development peak flow rates within this subbasin exceed pre-development levels. However,
there is an existing wet pond BMP located within the adjacent existing Twin Lakes development
that was designed to handle offsite drainage from the proposed Town Hall Commons property.
Based upon the previously approved design report for the Twin Lakes stormwater wetlands by
Withers & Ravenel (sealed by Hunter Freeman, PE on 6/9/2006), the adjacent stormwater.
wetland BMP #5 was designed for 2.11-acres of offsite drainage at 60% impervious (?.30-acres).
Conclusively, since the proposed subbasin #3 is only 0.95-acres with 0.16-acres if impervious,
the existing offsite wet pond BMP provides water quantity/quality treatment for subbasin #3.
Also included in this report is an analysis of the existing offsite Twin Lakes wet pond BMP
based upon asbuilt field survey information provided to The John R. McAdams Company, Inc.
by Withers & Ravenel. Please see the appropriate section of this report of more details associated
with the analysis of the existing offsite Twin Lakes wet pond BMP.
Subbasin 4
• This subbasin is located just south of subbasin #2, and drains off to the south. In the pre-
development condition, this 0.84-acre subbasin is entirely wooded (SCS CN = 77), with a pre-
• development time of concentration of 54.59 minutes. In the post-development condition, the
subbasin area decreases to 0.20 acres due to the proposed grading plan redirecting drainage away
from this subbasin. This subbasin is completely open space, and as a result, the post-development
SCS CN is 80, with the time of concentration assumed to be 5 minutes due to small size of the
subbasin. As can be seen in the Summary of Results, the post-development peak flow rates
within this subbasin was maintained at or below pre-development levels.
Subbasin 5A & 5B
These subbasins are located in the middle of the property, and drain towards the existing adjacent
Gardens at Town Hall Commons development along the eastern boundary of the site. In the pre-
development condition, these subbasins together total 1.67-acres and are a mix of impervious,
open, and wooded area (SCS CN = 76 & 77 respectively), with pre-development time of
concentrations of 70.02 minutes and 47.59 minutes respectively. However, for the purposes of
the pre-post analysis for this subbasin, the computed pre-development peak flowrates for
subbasin #5A and #513 are not utilized in this analysis (see further discussion in next paragraph).
In the post-development condition, these subbasins in addition to the offsite drianage area
associated with the Gardens at Townhall Commons development become the drainage areas to
the proposed stormwater wetland #2 and #3, which together combine to a total area of 7.36-acres.
The drainage areas to the proposed stormwater wetlands #2 and #3 contain mostly proposed
development, and as a result; the post-development SCS CN to stormwater wetland #2 is 88,
SCS CN to stormwater wetland #3 is 85, with the the time of concentration for both assumed to
be 5 minutes due to the amount of impervious area and piped storm drainage system.
Since the existing Gardens at Townhall Commons stormwater wetland is being removed as part
of this proposed development and the proposed wetland outfall will coincide with the location of
• the existing stormwater wetland outfall, it was agreed to with the Town of Morrisville that the
approved. pre-development hydrology for the Gardens at Townhall Commons project may be
utilized as the basis for the pre-post analysis comparisions (hence the reason why the computed
pre-development peak flowrates for subbasins #5A and #513 were ultimately not utilized). More
specifically, using the approved pre-development hydrology input data from the approved design
by Priest Craven & Associates, Inc., pre-development peak flowrates were "recomputed" based
upon the "new" rainfall data (i.e. same rainfall data used in the post-development calculations).
The "recomputed" pre-development peak flowrates. were used as the basis to compare the post-
development peak flowrates from the proposed wetland #2 and #3 outfall to ensure the pre-
development condition as met by the existing Gardens at Townhall Commons stormwater
wetland outfall is maintained. As shown in the summary of results, the post-development peak
outflow from the combined outlet pipe for stormwater wetland #2 and #3 was maintained at or
below the "recomputed" pre-development peak flowrates (based upon "new" rainfall data) in the
1- and 10-year design storm events based upon the pre-development hydrology shown in the
approved Priest Craven & Associates design calculations.
Subbasin 6
This subbasin is located in the middle of the property, and drain towards the existing Neuse
buffered stream running through the southern end of the site. In the pre-development condition,
this subbasin is 3.47-acres and is a mix of impervious, open, and wooded area (SCS CN = 76),
with a pre-development time of concentration of 54.95 minutes. In the post-development
condition, the subbasin area decreases to 0.73-acres due to the proposed grading plan redirecting
drainage away from this subbasin. This subbasin is a mix of impervious, open, and wooded area
(SCS CN 73), with the time of concentration assumed to be 5 minutes due to small size of the
subbasin. As can be seen in the Summary of Results, the post-development peak flow rates
• within this subbasin was maintained at or below pre-development levels.
subbasin 7A
This subbasin is located on the southern end of the site, and drains toward the existing Neuse
buffered stream running through the southern end of the site. In the pre-development condition,
this 2.16-acre subbasin is entirely wooded (SCS CN = 63), with a pre-development time of
concentration of 24.37 minutes. In the post-development condition, the subbasin area increases to
2.22-acres (includes drainage area to proposed stormwater wetland #4*nd there is a stormwater
management facility (stormwater wetland 94) proposed in this subbasin. This subbasin contains
mostly. proposed development, and as ,a result, the post-development SCS CN to stormwater
wetland #4 is 86 and the SCS CN to the bypass area is 63, with the the time of concentration for
both areas assumed to be 5 minutes due to the amount of impervious area and piped storm
drainage system. As can be seen in the Summary of Results, the proposed stormwater wetland #4
will provide detention such that the pre-development peak flow rates are no greater than post-
development peak flow rates in the 1- and 10-year design storm events.
Subbasin 7B & 7C
These subbasins are located along the southern property boundary and are comprised of
completely of offsite drainage. Subbasin #713 drains to an existing pond, which was modeled in .
this analysis. For the purposes of the pre-post analysis, it was assumed that the elevation
difference between the existing pond top of dam and existing pond normal pool elevation is 1
vertical foot. Therefore, the storage volume modeled within the existing pond was computed by
taking the surface area of the pond at normal pool based upon GIS contours and multiplying it by
1 foot. The principal spillway for the existing pond is a weir, which based upon a site visit
appreared to be approximately 3-foot wide at the bottom and sloping up gradually at a 10:1 slope
up to the top of dam elevation. Please see the site photos and calculations of the existing pond
• stage-storage and stage-discharge functions in the pre-development hydrology section of this
report. The existing pond remains the same from pre- to post-development, and therefore was
modeled the same in both scenarios. These subbasins combine and drain towards the existing
Neuse buffered -stream running through the southern end of the site. In the pre-development
condition, these subbasins together total 4.38-acres and are a mix of impervious, open, and
wooded area (subbasin 7B SCS CN = 77; subbasin 7C SCS CN = 96), with a pre-development
time of concentration of 36.13 minutes and 5 minutes (713 & 7C respectively). In the post-
development condition, these subbasins combine and the total area increases slightly to 4.42-
acres (subbasin 7C remains unchanged from the pre-development condition). Subbasin 7B is a
mix of wooded/open space, while 7C contains the clubhouse/amenity area associated with the
existing development located immediately upstream. As a result, the post-development SCS CN
is 78 for subbasin 7B and-96 for subbasin 7C (same as pre-development due to offsite drainage),
with the time of concentration assumed to be 5 minutes for 7C due to the amount of offsite piped
impervious drainage and 36.48 minutes for 7B due to overland flow segment associated with
offsite drainage. There subbasins combine and are a part of the pre-post analysis area included
with the proposed dry detention pond.
.Conclusion
If the development on this tract is built as proposed within this report, then the requirements set
forth in the Town of Morrisville Stormwater Runoff Policy will be met with the proposed
stormwater management plan. However, modifications to the proposed development may
require that this analysis be revised. Some modifications that would require this analysis to be
revised include:
• 1. The proposed site impervious surface exceeds the amount accounted for in this report.
2. The post-development watershed breaks change significantly from those used to prepare this
report.
S The above m8idtfications may result in the assumptions within this report becoming invalid. The
comf)utations within this report will need to be revisited if any of the above conditions become
apparent as development of the proposed site moves forward.

0

TOWN HALL COMMONS
PLT-10000
SUMMARY OF RESULTS
J. FINCH, PE
10/15/2010
=> RELEASE RATE MANAGEMENT RESULTS
SUBBASIN #1
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 1.20 1.28 0.08 6.67%
10-Year 3.37 3.27 -0.10 -2.97%
SUBBASIN #2
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 0.85 0.31 -0.54 -63.53%
10-Year 2.52 2.43 -0.09 -3.57%
SUBBASI N #3 (*NOTE: DR AINS TO EXISTING OF FSITE TWIN LAKES WET POND)
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase %o Increase
[cfs] [%]
1-Year 1.04 1.96 0.92 88.46%
10-Year 3.01 4.64 1.63 54.15%
SUBBASIN #4
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 0.42 0.35 -0.07 -16.67%
10-Year 1.22 0.90 -0.32 -26.23%
SUBBASIN #5 (NOT E: SEE EX GARDENS AT TOWN HALL COMMONS OUTLET BELOW FOR PRE-POST)
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 0.74 N/A N/A N/A
10-Year 2.18 N/A N/A N/A

SUBBASIN #6
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 1.62 0.81 -0.81 -50.00%
10-Year 4.86 2.57 -2.29 -47.12%
SUBBASIN #7
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 7.07 6.98 -0.09 -1.27%
10-Year 18.71 18.50 -0.21 -1.12%
EXISTING SW WETLAND OUTLET (?. THE GARDENS AT TOWN HALL. COMMONS - PHASE 3 - NEW RAINFALL
Return Period Pre-Development
[cfs] Post-Development
[cfs] Increase % Increase
[cfs] [%]
1-Year 8.26 1.85 -6.41 -77.60%
2-Year 11.19 6.52 -4.67 -41.73%
10-Year 19.06 18.44 -0.62 -3.25%
25-Year 23.75 30.99 7.24 30.48%
100-Year 31.27 36.08 4.81 15.38%
•
TOWN HALL COMMONS SUMMARY OF RESULTS J. FINCH, PE
PLT-10000 10/15/2010
=> 1-YEAR STORM PRE-POST VOLUME SUMMARY
RUNOFF VOLUME SUM MARY
Facility ID Pre-Development
[cff Post-Development
[cf] Difference Storage Volume Provided
[cfJ [cfJ
To Wetland #1 10,971 21,576 10,606 16,289
To Wetland #2 10,559 18,537 7,978 8,269
To Wetland #3 14,668 23,318 8,650 8,777
To Wetland #4 2,024 7,148 5,124 5,287
_> TN-EXPORT SUMMARY
Total Site Area = 12.83 acres
Pre-development TN-Export = 9.23 lbs/yr
= 0.72 lbs/ac/yr
Post-development TN-Export Summary =>
Computed TN-Export Before Treatment = 102.75 lbs/yr
8.01 lbs/ac/yr
Computed TN-Export After Treatment = 63.78 lbs/yr
4.97 lbs/ac/yr
0
0
TOWN HALL COMMONS SUMMARY OF RESULTS J. FINCH, PE
PLT-10000 10/20/2010
•
•
•
_> SW WETLAND #1 SUMMARY
Return Period Inflow
[cfs] Outflow
[cfs] Max. WSE
[ft] Freeboard
[ft]
1-Year 9.20 0.12 371.89 3.11
2-Year 11.82 0.42 372.03 2.97
10-Year 18.62 2.22 372.63 2.37
25-Year 22.59 6.78 372.99 2.01
100-Year Free Outfall 28.90 10.02 373.52 1.48
100-Year (Worst Case Condition) 28.90 10.77 373.91 1.09
Design Drainage Area = 3.22 acres
Design Impervious Area = 1.63 acres

To of Dam = 375.00 ft
Required Surface Area at Normal Pool = 5924 sf

NWSE = 370.00
1" R/O Volume Pondin Depth = 0.77 ft
1" R/O Volume Pondin Elevation = 370.77 ft
Siphon Diameter= 1.375 inches
Total Number of Siphons = 1

Riser Shape = Box
Riser Length = 4 ft
Riser Width = 4 ft
Riser Crest = 372.80 ft

Orifice Diameter: = 6 inches
Orifice Invert Elevation = 371.80 ft
Total Number of Orifices = 3

Barrel Diameter = 15 inches
# of Barrels = 1
Invert In = 370.00 feet
Invert Out = 369.80 feet
Length = 39 feet
Slope = 0.0051 ft/ft
1 of 4
TOWN HALL COMMONS SUMMARY OF RESULTS J. FINCH, PE
PLT-10000 10/20/2010
•
•
r?
_> SW WETLAND #2 SUMMARY
Return Period Inflow
[cfs] Outflow
[cfs] Max. WSE
[ft] Freeboard
[ft]
1-Year 7.87 0.54 348.85 3.65
2-Year 10.29 1.54 349.14 3.36
10-Year 16.63 4.42 350.08 2.42
25-Year 20.35 8.25 350.44 2.06
100-Year Free Outfall 26.27 8.42 351.22 1.28
100-Year (Worst Case Condition) 26.27 8.48 351.34 1.16
Design Drainage Area = 3.00 acres
Design Impervious Area = 1.26 acres

To of Dam = 352.50 ft
Required Surface Area at Normal Pool = 4656 sf

NWSE = 347.50
1" R/O Volume Pondin Depth = 0.68 ft
1" R/O Volume Pondin Elevation = 348.18 ft
Siphon Diameter = 1.25 inches
Total Number of Siphons = 1

Riser Shape = Box
Riser Length = 4 ft
Riser Width = 4 ft
Riser Crest = 350.00 ft

Orifice Diameter = 6 inches
Orifice Invert Elevation = 348.65 ft
Total Number of Orifices = 3

Barrel Diameter = 15 inches
# of Barrels = 1
Invert In = 344.50 feet
Invert Out = 341.35 feet
Length = 35 feet
Slope = 0.0900 ft/ft
2 of 4
TOWN HALL COMMONS SUMMARY OF RESULTS J. FINCH, PE
PLT-10000 10/20/2010
•
•
C.
_> SW WETLAND #3 SUMMARY
Return Period Inflow
[cfs] Outflow
[cfs] Max. WSE
[ft] Freeboard
IN
1-Year 9.94 1.44 347.38 2.87
2-Year 13.36 5.10 347.77 2.48
10-Year 22.49 15.00 348.63 1.62
25-Year 27.91 22.95 348.80 1.45
100-Year (Free Outfall 36.57 27.80 349.23 1.02
100-Year (Worst Case Condition) 36.57 27.79 349.23 1.02
Design Drainage Area = 4.36 acres
Design Impervious Area = 1.24 acres

To of Dam = 350.25 ft
Required Surface Area at Normal Pool = 4843 sf

NWSE = 345.50
1" R/O Volume Pondin Depth = 0.86 ft
V R/O Volume Pondin Elevation = 346.36 ft
Siphon Diameter = 1.25 inches
Total Number of Siphons = 1

Riser Shape = Box
Riser Length = 5 ft
Riser Width = 5 ft
Riser Crest = 348.50 ft

Orifice Diameter = 12 inches
Orifice Invert Elevation = 347.00 ft
Total Number of Orifices = 3

Barrel Diameter = 24 inches
# of Barrels = 1
Invert In = 341.00 feet
Invert Out = 340.15 feet
Length = 45 feet
Slope = 0.0189 ft/ft
3 of 4
TOWN HALL COMMONS SUMMARY OF RESULTS J. FINCH, PE
PLT-10000 10/20/2010
•
•
•
_> SW WETLAND #4 SUMMARY
Return Period Inflow
[cfs] Outflow
[cfs] Max. WSE
[ft] Freeboard
[ft]
1-Year 3.11 0.05 351.67 2.33
2-Year 4.14 0.20 351.78 2.22
10-Year 6.88 1.02 352.40 1.60
25-Year 8.49 4.73 352.67 1.33
100-Year Free Outfall 11.07 9.26 352.80 1.20
100-Year (Worst Case Condition) 11.07 8.88 352.91 1.09
Design Drainage Area = 1.30 acres
Design Impervious Area = 0.68 acres

To of Dam = 354.00 ft
Required Surface Area at Normal Pool = 2462 sf

NWSE = 350.00
1" R/O Volume Pondin Depth = 0.84 ft
1" R/O Volume Pondin Elevation = 350.84 ft
Siphon Diameter = 0.75 inches
Total Number of Siphons = 1

Riser Shape = Box
Riser Length = 4 ft
Riser Width = 4 ft
Riser Crest = 352.50 ft

Orifice Diameter = 4 inches
Orifice Invert Elevation = 351.60 ft
Total Number of Orifices = 3

Barrel Diameter = 15 inches
# of Barrels = 1
Invert In = 348.00 feet
Invert Out = 347.75 feet
Length = 23 feet
Slope = 0.0109 ft/ft
4 of 4
•
0
•
1
1 MISCELLANEOUS SITE DATA
2 PRECIPITATION DATA
3 WATERSHED SOIL DATA
APPROVED DESIGN CALCULATIONS
4
FOR PREVIOUSLY CONSTRUCTED
BMPS
PRE-DEVELOPMENT HYDROLOGIC
5 CALCULATIONS
POST-DEVELOPMENT HYDROLOGIC
6 CALCULATIONS
FINAL STORMWATER WETLAND #7
7 DESIGN CALCULATIONS
FINAL STORMWATER WETLAND #2
8 DESIGN CALCULATIONS
FINAL STORMWATER WETLAND #3
9 DESIGN CALCULATIONS
10 FINAL STORMWATER WETLAND #4
DESIGN CALCULATIONS

11 ANALYSIS OF EXISTING OFFSITE TWIN
LAKES WET POND BMP

1
12 FINAL TN EXPORT CALCULATIONS
•

MISCELLANEOUS SITE DATA
0

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Name: CARY Location: 035' 50' 11.97" N 078' 50'52.50" W NAD 27
Date: 5/25/2010
Scale: 1 inch equals 2000 feet
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Name of Stream Description
Cuff. Class Date Basin Stream Index #
Perry Creek From dam at Greshams C;NSW 05/01/88 Neuse 27-25-(2)

named Lake to Neuse River
From source to dam at
B;NSW
05/01/88
Neuse
27-25-3-(1)
Tributary near Camp Durant
Neuse
Unnamed From dam at Camp C;NSW 05/01/88 Neuse 27-25-3-(2)
Tributary near Durant to Perry Creek
Neuse
Harris Creek From source to Neuse C;NSW 05/01/88 Neuse 27-26
(Peeples Creek) River
(Wake Crossroads
Lake)
Hodges Mill From source to water B;NSW 05/01/88 Neuse 27-26-1-(1)
Creek (Lake Mirl) intake at Lake Mirl
Hodges Mill Creek From water intake at C;NSW 05/01/88 Neuse 27-26-1-(2)
Lake Mirl to Harris
Creek
Beaverdam Creek From source to Neuse C;NSW 05/01/88 Neuse 27-27
(west side of River
Neuse River)
Rocky Creek From source to Neuse C;NSW 05/01/88 Neuse 27-28
River
Beaverdam Creek From soruce to Neuse C;NSW 05/01/88 Neuse 27-29
(east side of River
Neuse River)
(Neuseco Lake,
Beaverdam Lake)
ridges Creek
L
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Ri C;NSW 05/01/88 Neuse 27-30
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ri
ges
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-Milburnie Creek From source to Neuse C;NSW 05/01/88 Neuse 27-31
(Milburnie Lake) River
Mango Creek From source to Neuse C;NSW 05/01/88 Neuse 27-32
River
'Crabtree Creek From source to
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Crabtree Creek From mouth of C;NSW 05/01/88 Neuse 27-33-(10)
Richlands Creek to
Neuse River
Crabtree Creek From backwaters of B;NSW 04/01/94 Neuse 27-33-(3.5)
(Crabtree Lake) Crabtree Lake to mouth
of Richlands Creek
Richlands Creek From source to C;NSW 05/01/88 Neuse 27-33-11
Crabtree Creek
Hare Snipe Creek From source to dam at B;NSW 05/01/88 Neuse 27-33-12-(1)
(Lake Lynn) Lake Lynn
Hare Snipe Creek From dam at Lake Lynn C;NSW 05/01/88 Neuse 27-33-12-(2)
to Crabtree Creek
House Creek From source to C;NSW 05/01/88 Neuse 27-33-13
Crabtree Creek
Mine Creek From source to C;NSW 05/01/88 Neuse 27-33-14
Crabtree Creek
•
Page 7 of 13 2010-05-22 07:08:19
•
PRECIPITATION DATA
•
•
TOWN HALL COMMONS
PLT-l 0000
Precipitation Frequency Data Server Page 1 of 3
POINT PRECIPITATION r
7 FREQUENCY ESTIMATES
FROM NOAA ATLAS 14 '
• North Carolina 35.836575 N 78.847944 W 351 feet
from "Precipitation-Frequency Atlas of the United States" NOAA Atlas 14, Volume 2, Version 3
G.M. Bonnin. D. Martin. B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, SIIVeI' Spring. Maryland, 2004
I
* Upper bound of the 90% confidence interval
Precipitation Frequency Estimates (inches)
ARI**
(years)
W
F10
mm 15

min 30

min 60

min 120

min

hr

hr 12

hr M24 48

hr

[d4
ay

ay 10

day 1 20

1 day 1 30

1 day 1 45

1 day 1 60

1 day
I 0.43 0.69 0.86 ].18 1.48 1.72 1.83 2.20 2.60 3.05
3.52 3.9
1
4.50
5.12
6.82
8.45
10.71
12.80
2 0.51 0.81 1.02 1.41 1.76 2.06 2.19 2.63 3.11 3.68 4.24 4.68 5.37 6.08 8.04 9.92 12.53 14.93
0 0.58 0.93 1.18 1.67 2.14 2.53 2.70 3.25 3.85 4.59 5.25 5.75 6.52 7.30 9.50 11.53 14.33 16.84
10 0.64 1.03 1.30 1.89 2.46 2.92 3.13 3.77 4.50 5.31 6.03 6.60 7.42 8.25 10.66 12.77 15.73 18.33
25 0.71 1.13 1.43 2.12 2.82 3.40 3.67 4.44 5.34 6.28 7.08 7.74 8.66 9.54 12.23 14.42 17.56 20.24
50 0.75 1.20 1.52 2.29 3.10 3.78 4.13 5.00 6.04 7.05 7.91 8.64 9.64 10.55 13.48 15.69 18.96 21.70
100 0.79 1.26 1.59 2.44 3.37 4.15 4.58 5.56 6.76 7.83 8.75 9.57 10.65 11.58 14.74 16.97 2036 23.10
200 0.83 1.32 1.66 2.58 3.62 4.S1 5.03 6.14 7.52 8.64 9.61 10.50 11.68 12.63 16.03 18.25 21.71 24.46
500 0.87 1.37 1.73 2.75 3.94 4.98 5.63 6.92 8.56 9.74 10.77 11.78 13.08 14.04 17.77 19.95 23.53 26.21
1000 0.90 1.41 1.77 2.87 4.19 5.35 6.14 7.58 9.46 10.61 11.65 12.78 14.17 15.14 19.14 21.25 24.90 27.51
The upper bound of the confidence interval at 90% confidence level is the value which 5% of the simulated quantile values for a given frequency are greater than.
These precipitation frequency estimates are based on a partial duration series. ARI is the Average Recurrence Interval.
Please refer to NOIMAht t4lDiotrr?l for more information. NOTE: Formatting prevents estimates near zero to appear as zero.
4 500 0.71 1.12 1.41 2.25 3.23 4.01 4.53 5.61 6.-9378 33 9.14 10.04 11.22 12.10 15.27 17.28 20.73 2328
* Lower bound of the 90% confidence interval
Precipitation Frequency Estimates (inches)
ARI**

(years) ?5

mm 10

min 15

min 30

mm 60

min 120

mm ?3

hr Mh j 12

hr 1 24

1 hr 1 48

1 hr
4
[day
;J
d
a
10

day 1
20

1 day 1
30

1 day 1
45

1 day 1
60

1 day

=1 6
0.3 0.58 0.73 1.00 1.24 1.44 1.53 1.85 2.21 2.66 3.05 3.41 3.96 4.52 6.02 7
.49
9.63
11.58
=2 0.43 0.68 0.86 1.18 1.48 1.72 1.83 2.22 2.64 3.21 3.68 4.08 4.72 5.36 7.10 8.79 11.27 13.
0.49 0.78 0.99 1.41 1.81 2.11 2.25 2.73 3.26 4.01 4.55 5.02 5.73 6.43 8.37 F10201 1 2.88 15.21
10 0.54 0.87 1.09 1.59 2.07 2.42 2.61 3.17 3.81 4.63 5.22 5.75 6.52 7.26 9.37 11.29 14.13 16.53
25 0.59 0.95 1.20 1.77 2.36 2.81 3.05 3.72 4.50 5.46 6.12 6.71 7.59 8.37 10.72 12.71 15.73 18.22
50 0.63 1.00 1.27 1.91
-1 2.59
-1 3.12 3.41 4.17 5.07 6.11 6.81 7.48 8.41 9.23 11.77 13.79 16.94 19.47
500 0.66 1.05 1.33 2.031 F2 80 3.39 3.75 4.61 5.62 6.76 7.50 8.24 9.25 10.09 12.81 14.86 18.10 20.67
200 0.69 1.09 1.37 2.13 2.99 3.67 4.09 5.04 6.19 E 18 .20 9.01 10.09 10.95 13.86 15.91 19.25 21.82

1000 0.73 1.15 1.44 2.33 3.40 4.28 4.88 6.06 7.54 9.02 9.86 10.83 12.10 12.96 16.35 18.33 21.84 24.36
I Me lower pound or the confidence interval at 90% confidence level is the value which 5% of the simulated quantile values for a given frequency are less than.
These precipitation frequency estimates are based on a partial duration maxima series. ARI is the Average Recurrence Interval.
http://hdsc.nws.noaa. gov/cgi-binlhdsc/buildout.perl?type=pf&units=us&series=pd&statena... 5/25/2010
' These precipitation frequency estimates are based on a partial duration series. AM is the Average Recurrence Interval.
Please refer to.NOAAAM 14 for more information. NOTE: Formatting forces estimates near zero to appear as zero.
Precipitation Frequency Data Server
Please refer to NDAAA{tc 14 for more information. NOTE. Formatting prevents estimates near zero to appear as zero
Text version of tables
Partial duration based Point Precipitation Frequency Estimates - Version: 3
35.836575 N 78.847944 W 351 ft
•
.Maps -
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1 2 5 10 25 50 100 200 500 1000
Average Recurrence Interval (years)
Tue May 25 11:35:28 2010
Duration
5-min - 30-min -a` 3-hr 24-hr 7-day - 30-day -B-
10-min -+- 60-min = 6-hr 48-hr 10-day 45-day a
15-min 120-m * 12-hr d 4-day -i- -I*- 60-day
e
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Partial duration based Point Precipitation Frequency Estimates - Version: 3
35.836575 N 78.847944 W 351 ft
Average Recurrence Interval
( ars)
1 ,a 2 + 5 -? 10 CIE 25 -6- 50 -*- 100 - 200 500 1000

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Tue May 25 11:35:27 2010
Page 2 of 3
http://hdsc.nws.noaa.gov/cgi-binlhdsc/buildout.perl?type=pf&units=us&series=pd&statena... 5/25/2010
Precipitation Frequency Data Server
_z
z
•
_Z
-4Location
z
_z
c
01.
17o-w 118-w 1 oo-W 90?W 80 W 70 W
These maps were produced using a direct map request from the
Swr.
71= Mm
Please read disclaimer (or more information.
11
Other Maps/Photographs -
LEGEND
State - Connector
County Stream
Indian Resv Military Area
Lake/PondlOcean National Park
-- Street ? _1 Other Park
- Expressway City
- Highway 2 C$unty6 .8 mi
Scale 1:228583 2 11
average--true scale depends on non4tor8resolution
Page 3 of 3
View USGJ dizital orthoohoto auadrangle (DOO) covering this location from TerraServer; USGS Aerial Photograph may also be available
from this site. A DOQ is a computer-generated image of an aerial photograph in which image displacement caused by terrain relief and camera
tilts has been removed. It combines the image characteristics of a photograph with the geometric qualities of a map. Visit the USGS for more information.
Watershed/Stream Flow Information -
Find the Watershed for this location using the U.S. Environmental Protection Agency's site.
Climate Data Sources -
Precipitation frequency results are based on data from a variety of sources, but largely NCDC The following links provide general information
about observing sites in the area, regardless of if their data was used in this study. For detailed information about the stations used in this study,
please refer to NOM Atlas 14 Document.
Using the National Climatic Data Center's (NCDC) station search engine, locate other climate stations within:
+/-30 minutes ...OR +1-1 degree of this location (35.836575/-78.847944). Digital ASCII data can be obtained directly from NCDC
Hydrometeorological Design Studies Center
DOCtNOAA/Natlonal Weather Service
1325 East-West Highway
Silver Spring, MD 20910
[phone]
Questions'?:
aLscw=
r?
http://hdsc.nws.noaa.gov/cgi-binlhdscibuildout.perl?type=pf&units=us&series=pd&statena... 5/25/2010
Type.... Design Storms
Name.... Town Hall Common
Page 1.01
.File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWM+'Design.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
DESIGN STORMS SUMMARY
Design Storm File,ID = Town Hall Common
Storm Tag Name = 1
Data Type, File, ID
Storm Frequency
Total Rainfall Depth
Duration Multiplier
Resulting Duration
Resulting Start Time
Synthetic Storm TypeII 24hr
1 yr
2.8400 in
1
1440.00 min
.00 min Step= 6.00 min End= 1440.00 min
Storm Tag Name = 2
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.4300 in
Duration Multiplier = 1
Resulting Duration = 1440.00 min
• Resulting Start Time= .00 min Step= 6.00 min End= 1440.00 min
Storm Tag Name = 10
Data Type, File, ID
Storm Frequency
Total Rainfall Depth
Duration Multiplier
Resulting Duration
Resulting Start Time
Synthetic Storm TypeII 24hr
10 yr
4.9600 in
1
1440.00 min
.00 min Step= 6.00 min End= 1440.00 min
Storm Tag Name = 100
Data Type, File, TD = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 7.3000 in
Duration Multiplier = 1
Resulting Duration 1440.00 min
Resulting Start Time= .00 min Step= 6.00 min End= 1440.00 min
Storm Tag Name = WQ Vol
Data Type, File, ID
Storm Frequency
Total Rainfall Depth
Duration Multiplier
Resulting Duration
Resultinq Start Time
Synthetic Storm TypeII 24hr
1 yr
1.0000 in
1
1440.00 min
.00 min Step= 6.00 min End= 1440.00 min
S/N: Bentley Systems, Irnc.
Bentley PondPack (10.00.027.00) 11:04 AM 10/7/2010
Type.... Design Storms
Name.... Town Hall Common
Design Storm File,ID =
0 File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
DESIGN STORMS SUMMARY
•
•
Storm Tag Name = 25
Town Hall Common
Page 1.02
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 25 yr
Total Rainfall Depth= 5.8600 in
Duration Multiplier = 1
Resulting Duration = 1440.00 min
Resulting Start Time= .00 min Step= 6.00 min End= 1440.00 min
SIN:
Bentley PondPack (10.00.027.00)
1'_•:04 AM
Bentley Systems, Inc.
10/7/2010
•
WATERSHED SOIL DATA
•
•
TOWN HALL COMMONS
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EcoEngineering
A division of The John R. McAdams Company, Inc.
•
MEMORANDUM
Date: November 29, 2010
To: Jeremy Finch, PE
From: George Buchholz, REM, PWS
Re: Town Hall Commons
Seasonal High Water Table
PLT-10000
h
4
/
0
l ?f`f

Field investigations were conducted on October 19, November 3, and.
November 9, 2010 at the proposed Town Hall Commons project to determine
the approximate seasonal high water table within four stormwater wetlands
planned for the project. Several soil borings were examined within each of
the four stormwater wetlands planned for the project. Each soil boring was
established within the anticipated normal pool limits for each of the planned
stormwater wetlands. Below is a brief summary of the soil types and the
approximate seasonal high water table depth from the soil surface for each of
the four stormwater wetlands.
491
Stormwater Wetland #1
Soil Type(s):
White Store sandy loam, 2 to 6 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
Soil Boring Results:
Approximately 3 soil borings were established within the the anticipated
normal pool limits. On average, it is anticipated that the approximate seasonal
high water table depth from the soil surface for this stormwater wetland is 24
inches.
Stormwater Wetland #2
Soil Type(s):
White Store sandy loam, 2 to 6 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
Research Triangle Park, NC
Post Office Box 14005
Research Triangle Park,
North Carolina 27709
290E Meridian Parkway
q jilllftrth Carolina 27713
80 46
919-2 -4262
919-361-2269 Fax
White Store sandy loam, 6 to 10 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
www.ecoengr.com Design Services Focused On Client Success
EcoEngineering
A division of The John R. McAdams Company, Inc.
•
Soil Boring Results:
Approximately 6 soil borings were established within the the anticipated
normal pool limits. On average, it is anticipated that the approximate seasonal
high water table depth from the soil surface for this stormwater wetland is 16
inches.
Stormwater Wetland 93
Soil Type(s):
White Store sandy loam, 2 to 6 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
White Store sandy loam, 6 to 10 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
C:
Soil Boring Results:
Approximately 4 soil borings were established within the the anticipated
normal pool limits. On average, it is anticipated that the approximate seasonal
high water table depth from the soil surface for this stormwater wetland is 23
inches.
Stormwater Wetland #4
Soil Type(s):
White Store sandy loam, 2 to 6 percent slopes, eroded: gently sloping to
moderately steep, moderately deep, moderately well drained, with slow
permeability.
Mayodan sandy loam, 6 to 10 percent slopes, eroded: gently sloping to
moderately steep, deep, well drained, with moderate permeability.
Soil Boring Results:
Approximately 3 soil borings were established within the the anticipated
normal pool limits. On average, it is anticipated that the approximate seasonal
high water table depth from the soil surface for this stormwater wetland is 23
inches.
General Soil Boring Observations
In general, the profile of the soil borings graded from light yellowish brown
silty-sandy loams near the surface to reddish brown with light-gray mottles
that are sandy at lower elevations and dark reddish brown with prominent gray
mottles that are clay at very low elevations. Below is a photograph of a
sample boring.
6

•
0
Soil boring profile located within Stormwater Wetland Number 2.
•
` F
a;
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APPROVED DESIGN CALCULATIONS FOR
PRE VIO USL Y CONSTR UCTED BMPS

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•
WITHERS RAVENEL
STORMWATER MANAGEMENT
REPORT
Twin Lakes - Parcel B
Cary, North Carolina
•
Prepared For
Wakefield Developers, LLC
32o9 Gresham Lake Road, Suite 16o
Raleigh, NC 27615
Prepared By:
WITHERS & RAVENEL, INC
u1 MacKenan Drive
Cary, North Carolina 27511
•
)une 2oo6
W&R Project No. 204177.71
OM2 C'. 4L
: ??
/if 160
Hunter Freeman, PE
TWIN LAKES PARCEL B
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
INTRODUCTION
The purpose of this study is to document pre- and post-development peak water surface elevations
for the 1-year, to-year, 5o-year, and ioo-year design storm events as well as document nitrogen
loading rates from the site. The goat is to ensure that the 2 proposed wet ponds meet standards set
by the Division of Water Quality for wet detention sizing and drawdown of the 1" 1" of runoff.
The site is located in Cary, NC, north of the intersection of Davis Drive and Aviation Parkway. The
entire site lies within the Neuse River basin. The existing site is undeveloped, and consists of mainly
pasture and woods. The proposed site will be developed as single family residences and will include
two wet detention ponds onsite for water quality. There are Town of Cary and natural riparian buffers
around the outfall channel, which flows from west to east through the center of the site.
The proposed ponds also serve to treat and attenuate flows from a portion of Parcel A, located on
the west side of Lake Grove Boulevard. That site was previously approved in September 2005. This
report supercedes any pond calculations submitted at that time. There is no change to the nitrogen
loading calculations for that portion of the Twin Lakes development.
The site is part of the Twin Lakes development. Additional stormwater management devices are
located on portions of the previously approved parcels, which have been designed to attenuate the
1-year discharge for the entire subdivision.

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5

Twin Lakes Parcel B 1 W&R Project 204177.71
Stormwater Management Report June 2006
TWIN LAKES PARCEL B
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
• METHODOLOGY
The stormwater study was conducted using the natural drainage features as depicted by Wake
County LIDAR topography (1-ft contours) and existing field surveys. Proposed drainage areas were
based on field surrey data and proposed development within the drainage areas.
The scope of work included the following analyses:
Hydrology
? Simulation of the 1-year, to-year, 5o-year, and loo-year rainfall events for the Cary, NC
area
? Formulation of the 1-year, to-year, 5o-year, and loo-year flood hydrographs for the pre-
and post-development drainage areas
Hydraulic
? Routing the 1-year, 1o-year, 5o-year, and loo-year flood hydrographs for pre-
development runoff from the site.
? Routing the i-year, 1o-year, 5o-year, and loo-year flood hydrographs for post-
development runoff through the proposed wet ponds.
The results of the hydrology calculations are used in the hydraulic analyses. The hydraulic design
requires the development of a stage-storage and stage-discharge function for the proposed ponds.
The rainfall/runoff hydrographs, stage-storage and stage-discharge functions have been compiled to
create a routing computer simulation model using Haestad Methods PondPack vio.o software. This
• PondPack model was then used to assess the peak water surface elevations for the design rainfall
events. The PondPack modeling results are provided as appendices to this report.
HYDROLOGY
The SCS Method was used to develop runoff hydrographs for the Type II, 24-hour duration, i-year
storm event in the Cary area, and the 24-hour duration rainfall curves determined using the NOAA
Atlas 14 rainfall data for Raleigh-Durham International Airport for the 1o-year, 5o-year and loo-year
storm events. This method requires three basic parameters: a curve number (CN), time of
concentration (tj, and drainage area.
Curve numbers were based on soil type and land use. Soil types were delineated from the Soil
Survey of Wake County, North Carolina (November 1970). Land use for existing conditions was based
on the most recent Wake County aerial photographs and field observations. Post development land
use is based on the proposed site plan. The curve numbers used in this study are listed in the
appendix of this report.
Times of concentration were calculated using methods described in the SCS publication "Urban
Hydrology for Small Watersheds, TR-55" and based on Wake County topographic maps and field
survey data. The post-development time of concentration was calculated for the drainage areas that
are piped to the ponds based on the flow time through the piped drainage systems and small areas
of sheet flow. The breakdown of the time of concentrations and the calculated values are found in
the appendices of this report.
•
Twin Lakes Parcel $ 2 W&R Project 204177.71
stormwater Management Report June 2oo6
TWIN LAKES PARCEL B
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
HYDRAULICS
• Computer simulated reservoir routing of the 1-year, io-year, 5o-year, and loo-year design storms
utilized stage-storage and stage-discharge functions. Stage-storage functions were derived from the
proposed grading of the new ponds. A non-linear regression relation for surface area versus
elevation was derived for each pond. This relation estimates the incremental volume of the basins to
the stage or elevation of the basins. Stage-discharge functions were developed to size the proposed
outlet structure for each wet detention pond.
CONCLUSIONS
Based on the routing study, the proposed ponds have sufficient volume to safely pass the loo-year
storm. The outlets were designed to discharge the first 1" of runoff over 2-5 days. Larger storm
events are passed though a riser.
Because the first 1" of runoff is being discharged over 2-5 days and released upstream of the buffer
limit, a25% nitrogen reduction credit was taken for each wet pond, followed by a 3o% reduction of
the remaining nitrogen for the sheet flow through the buffer.
BMPs 4 and 5 are permanent wet ponds that replace BMP 11, which was approved for Parcel A
Phase II. As stated in the pond report for Parcel A Phase II, the runoff from Parcel A is accounted for
in the design of the permanent BMPs.
•
•
Twin Lakes Parcel B 9 W&R Project zogi77.7i
Stormwater Management Report June 2006
TWIN LAKES PARCEL B
STORMWATER MANAGEMENT REPORT
CARY, NORTH CAROLINA
0 DESIGN SUMMARY
BMP #4 - PROPOSED WET DETENTION POND
• 2" drawdown orifice @ 356.00
• 5' x 5' slab top inlet box, crest @ 357.9
• 36" RCP Outlet Barrel
• Top of Dam = 360.00

Storm Event Peak Water
Surface Elevation
Freeboard
1-Year 358.48 1.52 ft 27.
1o-Year 358.95 1.05 ft 67.
j

5o-Year
359.15
0.85 ft
79.
cfs
ioo-Year 359.28 0.72 ft 80.•

•
BMP #5 - PROPOSED WET DETENTION POND
• 2" drawdown orifice @ 356.00
• 4' x 4' slab top inlet box, crest @ 357.2
• 24" CMP Outlet Barrel
• Top of Dam = 360.00

Storm Event Peak Water
Surface Elevation
Freeboard
outflow
1-Year 357.72 2.23 ft 18.78 cfs
1o-Year 358.18 1.82 It 48.1o cfs
5o-Year 358.41 1.59 ft 51.48 cfs
loo-Year 358.53 1.47 ft 52.40 cfs
Total for Site

Storm Event Pre-Development
Outflow Post-Development
Outflow with BMPs
1-Year 55.90 cfs 47.50 cfs
1o-Year 114.21 cfs 125.50 cfs
5o-Year 147.43 cfs 149.55 cfs
loo-Year 160.74 cfs 156.09 cfs
Twin Lakes Parcel B
Stormwater Management Report
W&R Project 204177.71
June 2006
•
PONDPACK OUTPUT
CALCULATIONS
0

Twin Lakes Parcel B W&R Project 204177.71
Stormwater Management Report June 2oo6
•
To BMP5
?d?nk 10
BW5
•
Addlink 20 -
To BMP4
BM
Untreated Areas
----------------------
Route 70 , A
Out Pbst
Pte Developmer

D
a
Lx
E
x
A
0
A
Out Pre
•
Job File: K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\PARCEL B.PPW
Rain Dir: K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\
•
JOB TITLE
------------
Project Date: 4/27/2005
Project Engineer: WR
Project Title: Twin Lakes Future BMPs
Project Comments:
•
•
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Table of Contents
i
C7
++++****++++++++++++++ MASTER SUMMARY +***++++++**+++*******
Watershed....... Master Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
RDU NOAA 14 Desi Design Storms ...................... 2.01
*+++*+++++++*+++++++++ TC CALCULATIONS +*+++++*+*+*+*++++*++
PRE DEVELOPMENT Tc Calcs ........................... 3.01
TO BMP4......... Tc Calcs ........................... 3.03
TO BMPS......... Tc Calcs ........................... 3.05
UNTREATED AREAS Tc Calcs ........................... 3.07
+*****+++++*++++++++*+ CN CALCULATIONS ++*+*+***+*++**++****
PRE DEVELOPMENT Runoff CN-Area ..................... 4.01
TO BMP4......... Runoff CN-Area ..................... 4.02
TO BMPS......... Runoff CN-Area ..................... 4.03
UNTREATED AREAS Runoff CN-Area ..................... 4.04
*+****++++++**+++++*++* POND VOLUMES +++*+****+**+*****+***+
BMP4............ Vol: Elev-Area ..................... 5.01
0
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Table of Contents
•
ii
BMP5............ Vol: Elev-Area ..................... 5.02
******************** OUTLET STRUCTURES *********************
BMP4 Outlet..... Outlet Input Data .................. 6.01
Composite Rating Curve ............. 6.05
BMP5 Outlet..... Outlet Input Data .................. 6.07
Composite Rating Curve ............. 6.11
•
•
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Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
MASTER DESIGN STORM SUMMARY
Network Storm Collection: RDU NOAA 14 Desi
Total
Depth Rainfall
Return Event in Type RNF ID
------------
10 ------
4.9800 ----------------
Time-Depth Curve --------
RDU NOAA --------
10yr
50 6.6300 Time-Depth Curve RDU NOAA 50yr
100 7.3700 Time-Depth Curve RDU NOAA 100yr
1 3.0000 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event ac-ft
- Trun
-----------
BMP4 ------
IN ----
POND ------
10 --------
-
5.033
BMP4 IN POND 50 7.217
BMP4 IN POND 100 8.209
BMP4 IN POND 1 2.506
BMP4 OUT POND 10 4.946 R
BMP4 OUT POND 50 7.127 R
BMP4 OUT POND 100 8.117 R
BMP4 OUT POND 1 2.429 R
BMP5 IN POND 10 3.370
BMP5 IN POND 50 4.834
BMP5 IN POND 100 5.498
BMP5 IN POND 1 1.679
Max
Qpeak Qpeak Max WSEL Pond Storage
hrs cfs
--- ft
-------- ac-ft
------------
---------
12.1500 -----
75.63
12.1500 92.77
12.1500 99.34
12.0000 40.52
12.2000 67.29 358.95 2.076
12.2000 79.33 359.15 2.167
12.2500 80.57 359.28 2.225
12.1000 27.45 358.48 1.865
12.1000 62.26
12.1000 75.67
12.1000 81.34
11.9000 30.37
•

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0
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
----------------- Type
---- Event
----- ac-ft Trun hrs cfs ft ac-ft

BMP5 OUT
POND -
10 ----------
3.333 --
R ---------
12.1500 --------
48.10 -------- ------------
358.18 1.795
BMP5 OUT POND 50 4.795 R 12.1500 51.48 358.41 1.897
BMP5 OUT POND 100 5.459 R 12.2000 52.40 358.53 1.955
BMP5 OUT POND 1 1.644 R 12.0500 18.78 357.72 1.598
*OUT POST JCT 10 9.461 R 12.2000 125.50
*OUT POST JCT 50 13.712 R 12.1500 149.55
*OUT POST JCT 100 15.646 R 12.1500 156.09
*OUT POST JCT 1 4.586 R 12.0500 47.50
*OUT PRE JCT 10 8.304 12.2000 114.21
*OUT PRE JCT 50 12.398 12.2000 147.43
*OUT PRE JCT 100 14.279 12.2000 160.74
*OUT PRE JCT 1 3.741 12.0500 55.90
DEVELOPMENT AREA 10 8.304 12.2000 114.21
DEVELOPMENT AREA 50 12.398 12.2000 147.44
PRE DEVELOPMENT AREA 100 14.279 12.2000 160.74
PRE DEVELOPMENT AREA 1 3.741 12.0500 55.90
TO BMP4 AREA 10 5.033 12.1500 75.63
TO BMP4 AREA 50 7.217 12.1500 92.77
TO BMP4 AREA 100 8.209 12.1500 99.34
TO BMP4 AREA 1 2.506 12.0000 40.52
TO BMP5 AREA 10 3.370 12.1000 62.26
TO BMP5 AREA 50 4.834 12.1000 75.67
TO BMP5 AREA 100 5.498 12.1000 81.34
TO BMP5 AREA 1 1.679 11.9000 30.37
UNTREATED AREAS AREA 10 1.181 12.1000 22.57
UNTREATED AREAS AREA 50 1.789 12.1000 29.19
UNTREATED AREAS AREA 100 2.070 12.1000 31.94
UNTREATED AREAS AREA 1 .513 11.9500 9.28
•
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Type.... Design Storms
Name.... RDU NOAA 14 Desi
Page 2.01
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
Title... Project Date: 4/27/2005
Project Engineer: WR
Project Title: Twin Lakes Future BMPs
Project Comments:
DESIGN STORMS SUMMARY
Design Storm File,ID = RDU NOAA 14 Desi
Storm Tag Name = 10
Data Type, File, ID = Time-Depth Curve RDU NOAA 10yr
Storm Frequency = 10 yr
Total Rainfall Depth= 4.9800 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 50
Data Type, File, ID = Time-Depth Curve RDU NOAA 50yr
Storm Frequency = 50 yr
Total Rainfall Depth= 6.6300 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 100
Data Type, File, ID = Time-Depth Curve RDU NOAA 100yr
Storm Frequency = 100 yr
Total Rainfall Depth= 7.3700 in
Duration Multiplier = 1
Resulting Duration = 23.9990 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9990 hrs
Storm Tag Name = 1
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 1 yr
Total Rainfall Depth= 3.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
r]

•
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Type.... Tc Calcs
Name.... PRE DEVELOPMENT
Page 3.01
ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
.......... ..............
...................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: Kirpich (TN)
Hydraulic Length 1700.00 ft
Slope .011000 ft/ft
Multiplier 1.000 (Tc Adjustment)
Avg.Velocity 2.08 ft/sec
Segment #1 Time: .2267 hrs
--------------------------------------------------------------------------
Total Tc: .2267 hrs
•
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------------------------------------------------------------------------
Tc Equations used...
----------------------------- -------------------------------------------
Kirpich (TN) ___________________
Tc = 0.00013 * (Lf**0.77) * (Sf**-0.385) * Mt
Where: Tc = Time of concentration, hrs
Lf = Flow length, ft
Sf = Slope, ft/ft
Mt = Tc Multiplier (Tc adjustment)
•
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Name.... TO BMP4
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........................................................
TIME OF CONCENTRATION CALCULATOR
Segment #I: Tc: User Defined
Segment #1 Time: .1700 hrs
------------------------------------------------------------------------
Total Tc: .1700 hrs
•
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Name.... TO BMP4
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------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
___= User Defined --- ===
Tc = Value entered by user
Where: Tc = Time of concentration
u
is
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............... .........:::.....
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: .0830 hrs
------------------------------------------------------------------
Total Tc: .0830 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
r?
u
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------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
==== User Defined
Tc = Value entered by user
Where: Tc = Time of concentration
•
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Name.... UNTREATED AREAS
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........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
..................................................:.....................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: .0830 hrs
------------------------------------------------------------------------
•
•
Total Tc: .0830 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
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------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
_=_= User Defined
Tc = Value entered by user
Where: Tc = Time of concentration
is
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Type.... Runoff CN-Area
Name.... PRE DEVELOPMENT
Page 4.01
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RUNOFF CURVE NUMBER DATA
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN

Woods - good
77 --
19.990 ----- ----- ------
77.00
Parcel A Phase II Roads 98 3.410 98.00
Parcel A Phase II Townhomes 98 1.630 98.00
Parcel A Phase II Open Space 80 5.410 80.00
Offsite (Apartments) 92 2.110 92.00
COMPOSITE AREA & WEIGHTED CN - --> 32.550 81.72 (82)
is
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RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description
-
-- CN acres %C %UC CN
-
---------------------------- -
Impervious Areas - Paved; open ditc ---
93 ---------
.750 ----- ----- ------
93.00
Residential Districts - 1/4 acre 87 4.730 87.00
Open space (Lawns,parks etc.) - Goo 80 .610 80.00
Parcel A Phase IT Roads 98 3.410 98.00
Parcel A Phase IT Townhomes 98 1.630 98.00
Parcel A Phase IT Open Space 80 5.410 80.00
COMPOSITE AREA & WEIGHTED CN --->
....................................
....................................
....
.... 16.540
..........
..........
............
............ 88.08 (88)
.............
.............
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RUNOFF CURVE NUMBER DATA
...........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description
-------------------
- CN acres %C %UC CN
-
----------- -
Impervious Areas - Paved; open ditc ---
93 ---------
1.470 ----- ----- ------
93.00
Residential Districts - 1/4 acre 8,7 6.650 87.00
Offsite (Apartments) 92 2.110 92.00
Open space (Lawns,parks etc.) - Goo 80 .850 80.00
COMPOSITE AREA & WEIGHTED CN ---> 11.080 88.21 (88)
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RUNOFF CURVE NUMBER DATA
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN
- acres %C %UC CN
---
---------------------------- ----
Residential Districts - 1/4 acre 87 ---------
1.540 ----- ----- ------
87.00
Woods - good 77 3.390 77.00
COMPOSITE AREA & WEIGHTED CN ---> 4.930 80.12 (80)
1/ 11
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Elevation Planimeter Area Al+A2+sgr(A1*A2) Volume Volume Sum
(ft)
------------ (sq.in) (sq.ft)
----------------
--- (sq.ft)
-
-
- {ac-ft) (ac-ft)

353.00 -
-
----- 11090 ---------
--
---
0 ---------
.000 -------------
.000
354.00 ----- 12382 35190 .269 .269
355.00 ----- 13724 39142 .300 .569
356.00 ----- 15135 43271 .331 .900
357.00 ----- 16603 47590 .364 1.264
358.00 ----- 18122 52071 .398 1.663
359.00 ----- 19693 56706 .434 2.096
360.00 ----- 21326 61512 .471 2.567
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-ELI) * (Areal + Area2 + sq.rt.(Areal*Area2))
where: ELI, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for ELI, EL2, respectively
Volume = Incremental volume between ELI and EL2
•
•
SIN: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Vol: Elev-Area
Name.... BMP5
Page 5.02
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw •
Elevation Planimeter Area Al+A2+sgr(Al*A2) Volume Volume Sum
(ft) (sq.in)
------------------------ (sq.ft)
--------- (sq.ft)
---------
-- (ac-ft)
-- (ac-ft)

353.00 -----
11285 ------
0 -------
.000 -------------
.000
354.00 ----- 12692 35945 .275 .275
355.00 ----- 14157 40254 .308 .583
356.00 ----- 15679 44735 .342 .925
357.00 ----- 17258 49387 .378 1.303
358.00 ----- 18894 54209 .415 1.718
359.00 ----- 20588 59205 .453 2.171
360.00 ----- 22339 64373 .493 2.664
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-ELI) * (Areal + Areal + sq.rt.(Areal*Area2))
where: ELI, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for ELI, EL2, respectively
Volume = Incremental volume between ELI and EL2
•
•
SIN: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Outlet Input Data
Name.... BMP4 Outlet
Page 6.01
0ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 353.00 ft
Increment = .10 ft
Max. Elev.= 360.00 ft
***************************************k*#****
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Inlet Box RO ---> CO 357.900 360.000
Culvert-Circular CO ---> TW 353.000 360.000
Orifice-Circular DD ---> TW 356.000 360.000
TW SETUP, DS Channel
•
•
5/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Outlet Input Data
Name.... BMP4 Outlet
Page 6.02
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = RO
Structure Type = Inlet Box
------------------
# of Openings ------------------
= 1
Invert Elev. = 357.90 ft
Orifice Area = 25.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 20.00 ft
Weir Coeff. = 3.100
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
•
C,
1x11
u
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Type.... Outlet Input Data
Name.... BMP4 Outlet
Page 6.03
0ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = CO
Structure Type =
------------------ Culvert-Circular
-
No. Barrels = -----------
1 ------
Barrel Diameter = 3.0000 ft
Upstream Invert = 353.00 ft
Dnstream Invert = 352.50 ft
Horiz. Length = 60.00 ft
Barrel Length = 60.00 ft
Barrel Slope = .00833 ft/ft
OUTLET CONTROL DATA ...
Mannings n = .0130
Ke - .5000 (forward entrance loss)
Kb = .007228 (per ft of full flow)
Kr = .5000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0018
Inlet Control M 2.0000
.
Inlet Control c .02920
Inlet Control Y = .7400
T1 ratio (HW/D) = 1.058
T2 ratio (HW/D) = 1.203
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at Tl & T2...
At T1 Elev = 356.17 ft ---> Flow = 42.85 cfs
At T2 Elev = 356.61 ft ---> Flow = 48.97 cfs
•
SIN: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Outlet Input Data
Name.... BMP4 Outlet
Page 6.04
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw •
OUTLET STRUCTURE INPUT DATA
Structure ID = DD
Structure Type = Orifice-Circular
------------------------------------
# of openings = 1
Invert Elev. = 356.00 ft
Diameter = .1700 ft
Orifice Coeff. _ .600
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min_ Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs .
•
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Type.... Composite Rating Curve
Name.... BMP4 Outlet
Page 6.05
ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge ---- --- ------------------
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
-- Contrib uting Structures

353.00
.00
Free - -----
Outfall -----
(no ---
Q: ------------------
RO,CO,DD)
353.10 .00 Free Outfall (no Q: RO,CO,DD)
353.20 .00 Free Outfall (no Q: RO,CO,DD)
353.30 .00 Free Outfall (no Q: RO,CO,DD)
353.40 .00 Free Outfall (no Q: RO,CO,DD)
353.50 .00 Free Outfall (no Q: RO,CO,DD)
353.60 .00 Free Outfall (no Q: RO,CO,DD)
353.70 .00 Free Outfall (no Q: RO,CO,DD)
353.80 .00 Free Outfall (no Q: RO,CO,DD)
353.90 .00 Free Outfall (no Q: RO,CO,DD)
354.00 .00 Free Outfall (no Q: RO,CO,DD)
354.10 .00 Free Outfall (no Q: RO,CO,DD)
354.20 .00 Free Outfall (no Q: RO,CO,DD)
354.30 .00 Free Outfall (no Q: RO,CO,DD)
354.40 .00 Free Outfall (no Q: RO,CO,DD)
354.50 .00 Free Outfall (no Q: RO,CO,DD)
354.60 .00 Free Outfall (no Q: RO,CO,DD)
4.70 .00 Free Outfall (no Q: RO,CO,DD)
4.80 .00 Free Outfall (no Q: RO,CO,DD)
4.90 .00 Free Outfall (no Q: RO,CO,DD)
355.00 .00 Free Outfall (no Q: RO,CO,DD)
355.10 .00 Free Outfall (no Q: RO,CO,DD)
355.20 .00 Free Outfall (no Q: RO,CO,DD)
355.30 .00 Free Outfall (no Q: RO,CO,DD)
355.40 .00 Free Outfall (no Q: RO,CO,DD)
355.50 .00 Free Outfall (no Q: RO,CO,DD)
355.60 .00 Free Outfall (no Q: RO,CO,DD)
355.70 .00 Free Outfall (no Q: RO,CO,DD)
355.80 .00 Free Outfall (no Q: RO,CO,DD)
355.90 .00 Free Outfall (no Q: RO,CO,DD)
356.00 .00 Free Outfall (no Q: RO,CO,DD)
356.10 .01 Free Outfall DD ( no Q: RO,CO)
356.20 .04 Free Outfall DD ( no Q: RO,CO)
356.30 .05 Free Outfall DD ( no Q: RO,CO)
356.40 .06 Free Outfall DD ( no Q: RO,CO)
356.50 .07 Free Outfall DD ( no Q: RO,CO)
356.60 .08 Free Outfall DD ( no Q: RO,CO)
356.70 .09 Free Outfall DD ( no Q: RO,CO)
•
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Type.... Composite Rating Curve
Name.... BMP4 Outlet
Page 6.06
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw •
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge ---------- ---------------
Elev. Q TW Elev Error
ft
- cfs ft +/-ft Contributing Structures
--
-----
356.80 -------
.09 -----
Free --- -----
Outfall -----------
DD (no Q: ---------------
RO,CO)
356.90 .10 Free Outfall DD (no Q: RO,CO)
357.00 .10 Free Outfall DD (no Q: RO,CO)
357.10 .11 Free Outfall DD (no Q: RO,CO)
357.20 .12 Free Outfall DD (no Q: RO,CO)
357.30 .12 Free Outfall DD (no Q: RO,CO)
357.40 _13 Free Outfall DD (no Q: RO,CO)
357.50 .13 Free Outfall DD (no Q: RO,CO)
357.60 .13 Free Outfall DD (no Q: RO,CO)
357.70 .14 Free Outfall DD (no Q: RO,CO)
357.80 .14 Free Outfall DD (no Q: RO,CO)
357.90 .15 Free Outfall DD (no Q: RO,CO)
358.00 2.11 Free Outfall RO,CO,DD
358.10 5.70 Free Outfall RO,CO,DD
358.20 10.34 Free Outfall RO,CO,DD
358.30 15.86 Free Outfall RO,CO,DD
358.40 22.10 Free Outfall RO,CO,DD
358.50
358.60 29.00
36.48 Free
Free Outfall
Outfall RO,CO,DD
RO,CO,DD •
358.70 44.55 Free Outfall RO,CO,DD
358.80 53.12 Free Outfall RO,CO,DD
358.90 62.18 Free Outfall RO,CO,DD
359.00 71.72 Free Outfall R0,C0,DD
359.10 78.77 Free Outfall RO,CO,DD
359.20 79.79 Free Outfall RO,CO,DD
359.30 80.75 Free Outfall RO,CO,DD
359.40 81.71 Free Outfall RO,CO,DD
359.50 82.69 Free Outfall RO,CO,DD
359.60 83.63 Free Outfall RO,CO,DD
359.70 84.59 Free Outfall RO,CO,DD
359.80 85.54 Free Outfall RO,CO,DD
359.90 86.49 Free Outfall RO,CO,DD
360.00 87.41 Free Outfall RO,CO,DD
•
5/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Outlet Input Data
Name.... BMP5 Outlet
Page 6.07
0ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 353.00 ft
Increment = .10 ft
Max. Elev.= 360.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Inlet Box RO ---> CO 351.200 360.000
Culvert-Circular CO ---> TW 353.000 360.000
Orifice-Circular DD ---> TW 356.000 360.000
TW SETUP, DS Channel
•
•
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Type.... Outlet Input Data
Name.... BMPS Outlet
Page 6.08
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = RO
Structure Type
------------------ = Inlet Box
------------------
# of openings = 1
Invert Elev. = 357.20 ft
Orifice Area = 16.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 16.00 ft
Weir Coeff. = 3.100
K, Reverse - 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
0

S/N: DOYXYWH3NLBE
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•
Withers & Ravenel
6/9/2006
Type.... Outlet Input Data
Name.... BMP5 Outlet
Page 6.09
&le.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = CO
Structure Type = Culvert-Circular
------------------------------------
No. Barrels = 1
Barrel Diameter = 2.5000 ft
Upstream Invert = 353.00 ft
Dnstream Invert = 352.50 ft
Horiz. Length = 60.00 ft
Barrel Length = 60.00 ft
Barrel Slope = .00833 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000 (forward entrance loss'
Kb = .009217 (per ft of full flow)
Kr = .5000 (reverse entrance loss;
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0018
• Inlet Control M _ 2.0000
Inlet Control c .02920
Inlet Control Y = .7400
T1 ratio (HW/D) = 1.058
T2 ratio (HW/D) = 1.203
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 355.65 ft ---> Flow = 27.16 cfs
At T2 Elev = 356.01 ft ---> Flow = 31.05 cfs
•
5/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
8:47 AM
Withers & Ravenel
6/9/2006
Type.... Outlet Input Data
Name._.. BMPS Outlet
Page 6.10
File.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = DD
Structure Type = Orifice-Circular
------------------------------------
# of openings = 1
Invert Elev. = 356.00 ft
Diameter = .1700 ft
Orifice Coeff. _ .600
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
•
is
•
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Name.... BMPS Outlet
Page 6.11
0 ile.... K:\04\04-170\04177.71-Twin Lakes Parcel B\H-H\Parcel B.ppw
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
--------- ------- -------- Converg e
-
------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures

353.00
.00 ----
Free Outfall --------
(no Q: ------------------
RO,CO,DD)
353.10 .00 Free Outfall (no Q: RO,CO,DD)
353.20 .00 Free Outfall (no Q: RO,CO,DD)
353.30 .00 Free Outfall (no Q: RO,CO,DD)
353.40 .00 Free Outfall (no Q: RO,CO,DD)
353.50 .00 Free outfall (no Q: RO,CO,DD)
353.60 .00 Free Outfall (no Q: RO,CO,DD)
353.70 .00 Free outfall (no Q: RO,CO,DD)
353.80 .00 Free Outfall (no Q: RO,CO,DD)
353.90 .00 Free Outfall (no Q: RO,CO,DD)
354.00 .00 Free Outfall (no Q: RO,CO,DD)
354.10 .00 Free Outfall (no Q: RO,CO,DD)
354.20 .00 Free Outfall (no Q: RO,CO,DD)
354.30 .00 Free Outfall (no Q: RO,CO,DD)
354.40 .00 Free Outfall (no Q: RO,CO,DD)
354.50 .00 Free Outfall (no Q: RO,CO,DD)
354.60 .00 Free Outfall (no Q: RO,CO,DD)
4.70 .00 Free Outfall (no Q: RO,CO,DD)
4.80 _00 Free Outfall (no Q: RO,CO,DD)
54.90 .00 Free Outfall (no Q: RO,CO,DD)
355.00 .00 Free Outfall (no Q: RO,CO,DD)
355.10 .00 Free Outfall (no Q: RO,CO,DD)
355.20 .00 Free Outfall (no Q: RO,CO,DD)
355.30 .00 Free outfall (no Q: RO,CO,DD)
355.40 .00 Free Outfall (no Q: RO,CO,DD)
355.50 .00 Free Outfall (no Q: RO,CO,DD)
355.60 .00 Free Outfall (no Q: RO,CO,DD)
355.70 .00 Free Outfall (no Q: RO,CO,DD)
355.80 .00 Free Outfall (no Q: RO,CO,DD)
355.90 .00 Free Outfall (no Q: RO,CO,DD)
356.00 .00 Free Outfall (no Q: RO,CO,DD)
356.10 .01 Free Outfall DD (no Q: RO,CO)
356.20 .04 Free Outfall DD (no Q: RO,CO)
356.30 .05 Free Outfall DD (no Q: RO,CO)
356.40 .06 Free Outfall DD (no Q: RO,CO)
356.50 .07 Free Outfall DD (no Q: RO,CO)
356.60 .08 Free Outfall DD (no Q: RO,CO)
356.70 .09 Free Outfall DD (no Q: RO,CO)
•
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PondPack (10.00.015.00) 8:47 AM 6/9/2006
Type.... Composite Rating Curve
Name.... BMP5 Outlet
Page 6.12
•
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ------ -- Converge ---------- ---------------
Elev. Q TW El ev Error .
ft cfs ft +/-ft
- Contributing Structures
-------------------------
--------
356.80 -------
.09 ------
Free -- -----
Outfall DD (no Q: RO,CO)
356.90 .10 Free Outfall DD (no Q: RO,CO)
357.00 .10 Free Outfall DD (no Q: RO,(--O)
357.10 .11 Free Outfall DD (no Q: 120,C0)
357.20 .12 Free Outfall DD (no Q: RO,CO)
357.30 1.69 Free 0utfa!1 RO,CO,DD
357.40 4.56 Free Outfall RO,CO,DD
357.50 8.28 Free Outfall RO,CO,DD
357.60 12.68 Free Outfall RO,CO,DD
357.70 17.69 Free Outfall RO,CO,DD
357.80 23.20 Free Outfall RO,CO,DD
357.90 29.18 Free Outfall RO,CO,DD
358.00 35.64 Free Outfall RO,CO,DD
358.10 42.51 Free Outfall RO,CO,DD
358.20 49.80 Free Outfall RO,CO,DD
358.30 50.74 Free Outfall RO,CO,DD
358.40 51.43 Free Outfall RO,CO,DD
358.50 52.16 Free Outfall RO,CO,DD
358.60 52.85 Free Outfall RO,CO,DD
358.70 53.54 Free Outfall RO,CO,DD
358.80 54.21 Free Outfall RO,CO,DD
358.90 54.89 Free Outfall RO,CO,DD
359.00 55.56 Free Outfall RO,CO,DD
359.10 56.21 Free Outfall RO,CO,DD
359.20 56.87 Free Outfall RO,CO,DD
359.30 57.51 Free Outfall RO,CO,DD
359.40 58.16 Free Outfall RO,CO,DD
359.50 58.79 Free Outfall RO,CO,DD
359.60 59.43 Free Outfall RO,CO,DD
359.70 60.05 Free Outfall RO,CO,DD
359.80 60.68 Free Outfall RO,CO,DD
359.90 61.27 Free outfall RO,CO,DD
360.00 61.88 Free Outfall RO,CO,DD
C7
is
SIN: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
Appendix A
•
Index of Starting Page Numbers for ID Names
A-1
----- B -----
BMP4... 5.01
BMP4 Outlet... 6.01, 6.05
BMPS... 5.02
BMPS Outlet... 6.07, 6.11
----- P -----
PRE DEVELOPMENT.. . 3.01, 4.01
----- R -----
RDU NOAH 14 Desi. .. 2.01
----- T -----
TO BHA ... ).03, 4.02
TO BP-1E'5... 3.05, 4.03
----- U
UNI'REF,TF,D AREAS..
. 3.07, 4.04
----- W -----
Watershed... 1.01
C,
•
SIN: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 8:47 AM 6/9/2006
•
BMP SIZING
CALCULATIONS
41
0
Twin Lakes Parcel B W&R Project zoyi77.7i
Stormwater Management Report June 2oo6
•
•
0
Twin Lakes BMP Sizing.xls
Project Name: Twin Lakes - Parcel B Pro #: 204177.71
• i /Stat : Cary, NC Date: 6-Apr-06
Table 1.1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
Removal Ffficiencv in the Piedmont
% Impervious
Cover Permanent Pool Dept
3.0 4.0 5.0 6.0 h (feet)
7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1-05 0.90 0.82 .0.77
s0 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
F 80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
Source: NLUtNK/UWQ Stonnwater Best Management Practices, pg. 5, April 1999
STORMWATER BMP 4 PARCEL B) - WET POND (25% TN Removal)

•

Land Use Area
(ac) % IA Imp. Area
(ac)
Impervious 0.74 100 0.7
Lots 4.73 40 1.9
Open Space 0.61 0 0.0
Parcel A Impervious 5.04 100 5.0
Parcel A Open 5.41 0 0.0
Totals 16.53 7.7
Total % Impervious Surface Area = 46.4 %
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio - 1.94 % From Table 1.1
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/100
SA = 0.321 acres
13969 sq. ft.
Normal pool elevation = 356.0 feet
Surface area provided = 0.347 acres
15135 sq. ft.
1-Inch Runoff Volume Calculation
Using the runoff volume calculations in the 'Simple Method' as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv - Runoff coefficient, in n.
I = Percent impervious
Rv = 0.47 in./in.
Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.644 acre-ft
28065 cu. ft.
Water quality pool elevation - 357.90 feet
Storage volume provided - 0.720 acre-ft
31363 cu. ft.
BMP4
• Project Name: Twin Lakes
Ci /State: Cary, NC
STORMWATER BMP 4 - WET POND (25% TN Removal)
is
Orifice Calculator
Q =Cd*A*(2gh)^(1/2)
Variables
WQ Volume:
Head:
Draw down time:
0.753 Acre-ft
1.9 ft
89 hrs
32800.68 cf
0.95 ft
320400 s
Orifice Area =
0.021814 sq. ft
Orifice Diameter = 1.999879 in
USE 2" DIAMETER ORIFICE
3.141209 sq. in
Project #: 204177.6
Date: 21-Apr-05
Constants
g = 32.2 ft/s2
Cd = 0.6
0
Twin Lakes BMP Sizing.xls
Project Name: Twin Lakes - Parcel B Project #: 204177.71
is i /State: Cary, NC Date: 6-Apr-06
Table 1.1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
Removal Effirienrv in the Pipdmnnt
% Impervious
Cover Permanent Pool Dept
3.0 4.0 5.0 6.0 h (feet)
7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
-----__...-..-. ?. ..., ..?....,......a.o Ica.IVM114r?cuIUR FWLEJUZ, p8• j,/%pm 1JYy
STORMWATER BMP 5 PARCEL B - WET POND (25% TN Removal)

Land Use Area
(ac) % IA Imp. Area
(ac)
Impervious 1.47 100 1.5
Lots 6.65 40 2.7
Open Space 0.85 0 0.0
Offsite 2.11 60 1.3
Totals 11.08 5.4
Total % Impervious Surface Area = 48.7 %
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio - 2.02 % From Table 1.1
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/] 00
SA = 0.224 acres
9749 sq. ft.
Normal pool elevation - 356.0 feet
Surface area provided = 0.360 acres
15679 sq. ft.
1-Inch Runoff Volume Calculation
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv = Runoff coefficient, in./in.
I = Percent impervious
Rv = 0.49 inJin.
0
Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.451 acre-ft
19640 cu. ft.
Water quality pool elevation = 357.20 feet
Storage volume provided - 0.461 acre-ft
20081 cu. ft.
BMP5
• Project Name: Twin Lakes
Ch -/-State: Cary, NC
STORMWATER BMP 5 - WET POND (25% TN Removal)
C
Orifice Calculator
Q =Cd*A*(2gh)^(1/2)
Variables
WQ Volume:
Head:
Draw down time:
0.461 Acre-ft
1.2 ft
69 hrs
20081.16 cf
0.6 ft
248400s
Orifice Area =
0.021675 sq. ft
Orifice Diameter = 1.993518 in
USE 2" DIAMETER ORIFICE
3.12126 sq. in
Project #: 204177.6
Date: 21-Apr-05
Constants
g = 32.2 ft/s2
Cd = 0.6
0
•
C
0
Twin Lakes Parcel B
Stormwater Management Report
NITROGEN LOADING
CALCULATIONS
W&R Project 204177.71
June 2006
Nitrogen Control Plan
Residential Subdivision with no known building footprints
• Project Title: Twin Lakes Parcel B
Part I. Riparian Buffers
Area includes riparian buffers? [ ] No [ X I Yes (j Exempt
If yes, [ X 150 foot [ ] 100 foot
River Basin? [ X 1 Neuse [ ] Cape Fear
Basis for Exemption
Show buffers on site plan.
Part II. Nitrogen Calculations (Method 1, Appendix C):
a. Subdivision Information
Number of lots 51
Total area of lots (excluding
R/W and open space) 11.38 ac
Number of lots / acre 4.48
Average lot size sf
Impervious area per lot 40% sf
b. Pre-development loading:
Type of Land Cover
Permanently protected undisturbed open
space (forest, unmown meadow)
Permanently protected managed open space
(grass, landscaping, etc.)
Impervious Area
• Pre-development Nitrogen Loading Rate (Ibs/ac/yr) _
c. Post-development loading:
Residentlal
Type of Land Cover
Permanently protected undisturbed open
space (forest, unmown meadow)
Permanently protected managed open space
(grass, landscaping, etc.)
Roads and Sidewalks
Lots (read TN export from Graph 2)
Post-development Nitrogen Loading Rate (lbs/ac/yr) _
Amount of Right-of-Way 3.21 ac
Percent of Right-of-Way
that is impervious area 75.00%
Amount of Right-of-Way
that is impervious area 2.41 ac
Total estimated impervious area 6.96 ac
TN Export
Area TN export coeff from use
facrrml Mcint-lurl /lhalurl
19.98 0.6 11.99
0 1.2 0
0 21.2 0
19.98 11.99
TOTAL
0.60
TN Export
Area TN export coeff from use
facrasl /Ihalne hm% /R,.h.A
1.54 0.6 0.92
4.65 1.2 5.58
2.41 21.2 51.09
11.38 9.2 104.70
19.98 162.29
TOTAL
8.12
Proposed BMP(s) Two Wet Ponds and Riparian Buffer Assessed Tax Value of Land per acre= NIA
Nitrogen Load after BMPs = 2.78 Ibs/ac/yr Estimated Buy Down = $0
Nitrogen Load offset by Payments = 0.00 Ibs/actyr
Net change in on-site N Load = _ 2.18 Ibs/ac/yr (Post BMP load less Pre-development N bad) I
Part III. Control of Peak Stormwater Flow (for 1 year, design storm)
Calculated Pre-development Peak Flow 55.90
Calculated Post-development Peak Flow 77.99
Proposed BMP(s) Two Wet Ponds
Post BMP Peak Flow 47.50 ** Includes a portion of Parcel A
• I, the undersigned, certify to the best of my knowledge that the above information is correct (affix seal).
Supply notes & details showing control of Nitrogen and peak stonnwater runoff. 3182006
V
No
rSE '
028442 ?i 47.' •?G J 111g?•' ??? 0"0
FRti???N
l??1 f l 111\\??.Qt

Nitrogen Loading Calculations
Project Name: Twin Lakes Parcel B
Project #. 204177.71
TOTALTRACT
Total Area: 870,329 sgft = 19.98 ac.
Roads and Sidewalks Impervious 104,98o sgft. = 2.41 ac.
Natural Open Space Area: 67,o82 sgft. = 1.54 ac.
Managed Open Space Area: 202,554 sgfL = 4.65 ac.
Residential Lot Area: 495,713 sgft. - 11.38 ac.
Estimated Pre-Development TN Loading
Date: 6/9/2oo6
Computed by: HCF
Type of Land Cover Acres TN Export Coeff. TN EXPORT bs/Yr)
(Ibs/ac/yd
Permanently Protected Undisturbed Area 19.99 o.6 11.99
Permanently Protected Managed Area 6.00 1.2 0.00
Totals 19.99 o.6 11-99
Estimated Post-Development TN Loading
Drainage Area 1: BMP 4 Wet Pond
Type of Land Cover Acres Export Coe . TN EXPORT bs/Yr)
Obs/ac/yr)
Permanently Protected Undisturbed Area 0.00 o.6 0.00
Permanently Protected Managed Area o.61 1.2 0.73
Impervious 0.74 21.2 15.69
Lots 4.73 9-z
43-52
Totals 6.o8 59-94
•
rsumatea tssnr Keauction torwet Pond: 25 %
Estimated Drainage Area 1 Nitrogen Loading Reduction: 14.98 Ibs/yr
Estimated BMP Reduction for Riparian Buffer: 30 %
Estimated Drainage Area 1 Nitrogen Loading Reduction: 13-49 Ibs/yr
Total: 28.47
Drainage Area 2: Wet Pond
Type of Land Cover Acres TN Export Coeff. TN EXPORT (Ibs/yr)
(Ibs/ac/yd
Permanently Protected Undisturbed Area 0.00 o.6 0.00
Permanently Protected Managed Area o.65 1.2 0.78
Impervious 1.67 21.2 35.40
Lots 6.65 9.2 61.18
Totals 8.97 36.18
cxrmare0 omr Keducuon Tor wet Fond: 25 %
Estimated Drainage Area 2 Nitrogen Loading Reduction: 9.05 lbs/yr
Estimated BMP Reduction for Riparian Buffer: 30 %
Estimated Drainage Area 1 Nitrogen Loading Reduction: 8.14 Ibs/yr
Tota I: 17.19
Drainage Area 3: Untreated
Type of Land Cover Acres Export Coe .
(Ibs/ac/yr) TN EXPORT pbs/yr)
Permanently Protected Undisturbed Area 1.54 o.6 0.92
Permanently Protected Managed Area 3.39 1.2 4-07
Impervious 0.00 21.2 0.00
Lots 0.00 9•z 0.00
Totals 4 93 4.99
t5tlmatea dMF Keauction: 0%
Estimated Drainage Area 4 Nitrogen Loading Reduction: o.oo Ibs/yr
•
Estimated Project Pre-BMP TN Export 101.11 Ibs/yr
Estimated Project BMP TN Removal: 45.66 Ibs/yr
Estimated Project TN Load Rate After BMPs: 2.78 Ibs/ac/yr
Estimated Project Composite Nitrogen Loading Rate Reduction: 45.15 %
•

PRE-DEVELOPMENT HYDROLOGIC
CALCULATIONS
U
C
TOWN HALL COMMONS
PLT-10000
N '
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0
N
0
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0 0 0 0 0 0 0 0 0 0 0
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•
r ?
•
TOWN HALL COMMONS
PLT-10000
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #1
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume: HSG 'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
•
0
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 1.40 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 1.40 acres
0.0022 sq.mi.
Composite SCS CN = 77
% Impervious = 0.0%
B. Time of Concentration Information
'Time of concentration is calculated using the SCS Segme ntal Approach (TR-55).
Segment 1: Overland Flow
Length = 124 ' ft
Height = 2.39 ft
Slope = 0.0193 ft/ft
Manning's n = 0.40 Woods - Light Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 25.00 minutes
Time of Concentration = 25.46 minutes
SCS Lag Time = 15.28 minutes (SCS Lag = 0.6* Tc)
Time Increment = 4.43 minutes (= 0.29*SCS Lag)
J. FINCH, PE
10/4/2010
Segment 2. Concentrated Flow
Length = 75 ft
Height = 2.12 ft
Slope = 0.0283 ft/ft
Paved ? = No
Velocity = 2.71 ft/sec
Segment Time = 0.46 minutes
Type.... Runoff CN-Area
Name.... SUB01-PRE
Page 2.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
77 1.400 77.00
COMPOSITE AREA & WEIGHTED CN ---> 1.400 77.00 (77)
•
is
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Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB01-PRE
Page 1.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 25-46 min
------------------------------------------------------------------------
Total Tc: 25.46 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010

SUB-BASIN #1
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010
•
•
C,
SUB-BASIN #1
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010
0
TOWN HALL COMMONS
PLT-10000
IV' ?9:
Assume:
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #2
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG 'C' = 20.0%
HSG'D' = 80.0%
Cover Condition SCS CN Comments
Impervious 98
Open 79 Assume good condition
Wooded 76 Assume good condition
A. Watershed Breakdown
•
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 79 0.00 Assume good condition
Onsite wooded 76 1.75 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 79 0.00 Assume good condition
Offsite wooded 76 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 1.75 acres
0.0027 sq.mi.
Composite SCS CN = 76
% Impervious = 0.0%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segmental Approach ('TR-55).
Segment 1: Overland Flow
Length = 139 ft
Height = 2.27 ft
Slope = 0.0163 ft/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 50.97 minutes
Time of Concentration = 52.43 minutes
SCS Lag Time = 31.46 minutes (SCS Lag = 0.6* Tc)
Time Increment = 9.12 minutes (= 0.29*SCS Lag)
J. FINCH, PE
10/4/2010
Segment 2. Concentrated Flow
Length = 221 ft
Height = 5.35 ft
Slope = 0.0242 ft/ft
Paved ? = No
Velocity = 2.51 ft/sec
Segment 77me = 1.47 minutes
•
Type.... Runoff CN-Area
Name.... SUB02-PRE
Page 2.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
76 1.750 76.00
COMPOSITE AREA & WEIGHTED CN ---> 1.750 76.00 (76)
...........................................................................
...........................................................................
•
•
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB02-PRE
Page 1.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 52.43 min
------------------------------------------------------------------------
Total Tc: 52.43 min
•

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
Assume:
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #3
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
r?
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 2.07 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 2.07 acres
0.0032 sq.mi.
Composite SCS CN = 77
% Impervious = 0.0%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segmental Approach ('TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 5.92 ft
Slope = 0.0296 f9/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 53.75 minutes
Time of Concentration = 55.00 minutes
SCS Lag Time = 33.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 9.57 minutes (= 0.29*SCS Lag)
J. FINCH, PE
10/4/2010
Segment 2: Concentrated Flow
Length = 189 ft
Height = 4.65 ft
Slope = 0.0246 ft/ft
Paved ? = No
Velocity = 2.53 ft/sec
Segment Time = 1.24 minutes
is
Type.... Runoff CN-Area
Name.... SUB03-PRE
Page 2.04
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
•
•
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
77 2.070 77.00
COMPOSITE AREA & WEIGHTED CN ---> 2.070 77.00 (77)
SIN:
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Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB03-PRE
Page 1.05
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
.........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 55.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 55.00 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
.SCS ' g

0
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #4
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume. HSG'A' = 0.0%
HSG'B'= 0.0%
HSG'C'= 1.2%
HSG'D' = 98.8%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 0.84 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 0.84 acres
0.0013 sq.mi.
Composite SCS CN = 77
% Impervious = 0.0%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 5.72 ft
Slope = 0.0286 ft/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 54.49 minutes
Time of Concentration = 54.59 minutes
SCS Lag Time = 32.76 minutes (SCS Lag = 0.6* Tc)
Time Increment = 9.50 minutes = 0.29*SCS La
J. FINCH, PE
10/4/2010
Segment 2: Concentrated Flow
Length = 14 ft
Height = 0.3 ft
Slope = 0.0214 ft/ft
Paved ? = No
Velocity = 2.36 ft/sec
Segment Time = 0.10 minutes
Type.... Runoff CN-Area
Name.... SUB04-PRE
Page 2.05
• File.... X.\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files \SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
77 .840 77.00
COMPOSITE AREA & WEIGHTED CN ---> .840 77.00 (77)
•
•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB04-PRE
Page 1.07
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 54.59 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 54.59 min
•
•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
• X: SCS Ct IVfBERS
Tied,
•
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin 45A
Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume: HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 47.3%
HSG'D' = 52.7%
Cover Condition SCS CN Comments
Impervious 98
Open 77 Assume good condition
Wooded 74 Assume good condition
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.02 -
Onsite open 77 0.13 Assume good condition
Onsite wooded 74 0.37 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 77 0.38 Assume ood condition
Offsite wooded 74 0.03 Assume good. condition
Offsite and 100 0.00 -
Total area = 0.93 acres
0.0015 sq.mi.
Composite SCS CN = 76
% Impervious = 2.2%
B. Time of Concentration Information
'Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 3.15 ft
Slope = 0.0157 ft/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 69.18 minutes
Time of Concentration = 70.02 minutes
SCS Lag Time = 42.01 minutes (SCS Lag = 0.6* Tc)
Time Increment = 12.18 minutes = 0.29*SCS La
J. FINCH, PE
10/4/2010
Segment 2: Concentrated Flow
Length = 196 ft
Height = 11.5 ft
Slope = 0.0587 ft/ft
Paved ? = No
Velocity = 3.91 ft/sec
Segment Time = 0.84 minutes
0
Type.... Runoff CN-Area Page 2.06
Name.... SUBOSA-PRE
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
76 .930 76.00
COMPOSITE AREA & WEIGHTED CN ---> .930 76.00 (76)
•

SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB05A-PRE
Page 1.09
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 70.02 min
----------------------------------------------------------------------
Total Tc: 70.02 min
r]

SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS J. FINCH, PE
PLT-10000 Pre-development - Subbasin 45B 10/4/2010

C,
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume: HSG'A' = 0.0%
HSG'B' = 0.0%
HSG 'C' = 1.4%
HSG'D' = 98.6%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.01 -
Onsite open 80 0.02 Assume good condition
Onsite wooded 77 0.71 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 0.74 acres
0.0012 sq.mi.
Composite SCS CN = 77
% Impervious = 1.4%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 8.35 ft
Slope = 0.0418 ft/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 46.84 minutes
Segment 2: Concentrated Flow
Length = 171 ft
Height = 9.43 ft
Slope = 0.0551 ft/ft
Paved ? = No
Velocity = 3.79 ft/sec
Segment Time = 0.75 minutes
Time of Concentration = 47.59 minutes
SCS Lag Time = 28.56 minutes (SCS Lag = 0.6* Tc)
Time Increment = 8.28 minutes = 0.29*SCS La
0
Type.... Runoff CN-Area
Name.... SUB05B-PRE
Page 2.07
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
•
•
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
77 .740 77.00
COMPOSITE AREA & WEIGHTED CN ---> .740 77.00 (77)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB05B-PRE

Page 1.11
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 47.59 min
------------------------------------------------------------------------
Total Tc: 47.59 min

•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000

Assume:
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #6
HSG
Impervious
Open
Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 6.3%
HSG'C' = 2.6%
HSG'D' = 91.1%
Cover Condition SCS CN Comments
Impervious 98
Open 79 Assume good condition
Wooded 75 Assume good condition
A. Watershed Breakdown

Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.04 -
Onsite open 79 0.00 Assume good condition
Onsite wooded 75 3.31 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 79 0.02 Assume good condition _
Offsite wooded 75 0.10 Assume good conditibri.
Offsite and 100 0.00 -
Total area = 3.47 acres
0.0054 sq.mi.
Composite SCS CN = 76
% Impervious = 1.2%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segmental Approach (TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 6.2 ft
Slope = 0.0310 ft/ft
Manning's n = 0.80 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 52.77 minutes
Time of Concentration = 54.95 minutes
SCS Lag Time = 32.97 minutes (SCS Lag = 0.6* Tc)
Time Increment = 9.56 minutes (= 0.29*SCS Lag)
Segment 2: Concentrated Flow
Length = 472 ft
Height = 23.45 ft
Slope = 0.0497 ft/ft
Paved ? = No
Velocity = 3.60 ft/sec
Segment Time = 219 minutes
J. FINCH, PE
10/4/2010
0
Type.... Runoff CN-Area
Name.... SUB06-PRE
Page 2.08
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
1?
LJ
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
76 3.470 76.00
COMPOSITE AREA & WEIGHTED CN ---> 3.470 76.00 (76)
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB06-PRE
Page 1.13
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 54.95 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 54.95 min
-------------------------
-------------------------

S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
"TIC k
•
0
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #7A
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume. HSG'A' = 0.0%
HSG'B' = 63.4%
HSG'C' = 0.0%
HSG'D'= 36.6%
Cover Condition SCS CN Comments
Impervious 98
Open 68 Assume good condition
Wooded 63 Assume good condition
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 68 0.00 Assume good condition
Onsite wooded 63 2.16 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 68 0.00 Assume good condition
Offsite wooded 63 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 2.16 acres
0.0034 sq.mi.
Composite SCS CN = 63
% Impervious = 0.0%
B. Time of Concentration Information
* "Time of concentration is calculated using the SCS Segme ntal Approach ('lR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 11.15 ft
Slope = 0.0557 ft/ft
Manning's n = 0.40 Woods - Dense Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 23.96 minutes
Time of Concentration = 24.37 minutes
SCS Lag Time = 14.62 minutes (SCS Lag = 0.6* Tc)
Time Increment = 4.24 minutes = 0.29*SCS La
J. FINCH, PE
10/4/2010
Segment 2: Concentrated Flow
Length = 118 ft
Height = 10.86 ft
Slope = 0.0920 ft/ft
Paved ? = No
Velocity = 4.89 ft/sec
Segment Time = 0.40 minutes
Type.... Runoff CN-Area
Name.... SUB07A-PRE
Page 2.09
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
63 2.160 63.00
COMPOSITE AREA & WEIGHTED CN ---> 2.160 63.00 (63)
...........................................................................
...........................................................................
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB07A-PRE
Page 1.15
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 24.37 min
------------------------------------------------------------------------
Total Tc: 24.37 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010

•
5Y
0
SUB-BASIN #7A
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010
• fi
•
•
SUB-BASIN #7A
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010

k
t 9 .?t d w- ?
?.

?y

Lill,

0
TOWN HALL COMMONS
PLT-10000
•I;`SCS ?LJRVE. jvLJMBE
Assume.
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #7B
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
??? pR11-?I)EVELOPMEI!IT?,? „? `" ; ?
A. Watershed Breakdown
•
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 - ;
Offsite open 80 0.05 Assume good condition
Offsite wooded 77 0.31 Assume good condition
Offsite and 100 0.00 -
Total area = 0.36 acres
0.0006 sq.mi.
Composite SCS CN = 77
% Impervious = 0.0%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segme ntal Approach (TR-SS).
Segment 1: Overland Flow
Length = 200 ft
Height = 4.05 ft
Slope = 0.0203 ft/ft
Manning's n = 0.40 Woods - Light Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 35.93 minutes
Time of Concentration = 36.13 minutes
SCS Lag Time = 21.68 minutes (SCS Lag = 0.6* Tc)
Time Increment = 6.29 minutes (= 0.29*SCS Lag)
J. FINCH, PE
10/4/2010
Segment 2: Concentrated Flow
Length = 37 ft
Height = 1.45 ft
Slope = 0.0392 ft/ft
Paved ? = No
Velocity = 3.19 ft/sec
Segment Time = 0.19 minutes
•
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS
PLT-10000 Pre-development - Subbasin 47B
•C. Reach Information
Concentrated Flow
Length = 313 ft
Height = 21.55 ft
Slope = 0.0688 ft/ft
Paved ? = No
Velocity = 4.23 ft/sec
Segment Time = 1.23 minutes

J. FINCH, PE
10/4/2010
0
Type.... Runoff CN-Area
Name.... SUB07B-PRE
Page 2.10
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
77 .360 77.00
•

COMPOSITE AREA & WEIGHTED CN ---> .360 77.00 (77)
.........................................................................
SIN:
Bentley PondPack (10.00.027.00) 11:08 AM
Bentley Systems, Inc.
10/7/2010
Type.... Tc Calcs
Name.... SUB07B-PRE
Page 1.17
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 36.13 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 36.13 min
•
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
•
.7
SUB-BASIN #713
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010
11 ;
w
?f t pia' ice. r w
? W ? 1 y0. ' 'YY . ?}, ?I14c tiw *rv fey
?n •
.;> is •.? - .. s r, O w
4 t t y?
y?? 1 J ?a r` „_?
fA.
0
•
•

i
try .. ?{. I ..
x I . a 6 e
"4 !.? ? i ? r ? v t•=
0
SUB-BASIN #713
OVERLAND FLOW SEGMENT PHOTOGRAPHS
AUGUST 18, 2010
TOWN HALL COMMONS
PLT-10000
•
•
Assume.
HYDROLOGIC CALCULATIONS
Pre-development - Subbasin #7C
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A'= 0.0%
HSG'B'= 2.0%
HSG'C' = 0.0%
HSG'D'= 98.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 2.96
Offsite open 80 0.15 Assume good condition
Offsite wooded 77 0.31 Assume good condition
Offsite and 100 0.60 -
Total area = 4.02 acres
0.0063 sq.mi.
Composite SCS CN = 96
% Impervious = 73.6%
B. Time of Concentration Information
* "Time of concentration was assumed to be 5 minutes due to amount of existing offsite impervious
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS La
J. FINCH, PE
10/4/2010
C. Reach Information
Concentrated Flow
Length = 122 ft
Height = 2.5 ft
Slope = 0.0205 ft/ft
Paved ? = No
Velocity = 2.31 ft/sec
Segment Time = 0.88 minutes
Type.... Runoff CN-Area
Name.... SUB07C-PRE
Page 2.11
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
96 4.020 96.00
COMPOSITE AREA & WEIGHTED CN ---> 4.020 96.00 (96)

•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB07C-PRE
Page 1.19
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 5.00 min
11
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Runoff CN-Area
Name.... CRAVEN - PRE
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
--------------------------------
Un-disturbed Areas - Wooded - Good ----
77 ---------
1.260 ----- ----- ------
77.00
Pasture - Good 80 .190 80.00
Offsite R-4 87 3.190 87.00
COMPOSITE AREA & WEIGHTED CN --->
...................................
...................................
.....
..... 4.640
..........
..........
............
............ 84.00 (84)
.............
.............
•
J
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
Type.... Outlet Input Data
Name.... Existing Pond
Page 1.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 366.00 ft
Increment = .10 ft
Max. Elev.= 367.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
----------------- ---- ------- --------- ---------
Weir-XY Points WR ---> TW 366.000 367.000
TW SETUP, DS Channel
•
•
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 10:5H AM 10/7/2010
Type.... Outlet Input Data
Name.... Existing Pond
Page 1.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = WR
Structure Type = Weir-XY Points
--------------------_----------------
# of Openings = 1
WEIR X-Y GROUND POINTS
X, ft Elev, ft
--------- ---------
.00 367.00
10.00 366.00
13.00 366.00
23.00 367.00
Lowest Elev. = 366.00 ft
Weir Coeff. = 3.000000
r?
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maxi mum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance - .00 cfs
•
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 10:59 AM 101712010
Type.... Composite Rating Curve
Name.... Existing Pond
•
•
•
Page 1.04
File.... X:\Project3\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
WS Elev, Total Q
----------------
Elev. Q
ft cfs
366.00 .00
366.10 .35
366.20 1.18
366.30 2.52
366.40 4.42
366.50 6.93
366.60 10.10
366.70 13.97
366.80 18.58
366.90 23.98
367.00 30.21
***** COMPOSITE OUTFLOW SUMMARY ****
------- Conver,
TW Elev Error
ft +/-ft
------- -----
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Notes
je -----------------------
Contributing Structures
------------------------
WR
WR
WR
WR
WR
WR
WR
WR
WR
WR
WR
/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 10:59 AM 10/7/2010
Type.... Vol: Elev-Area
Name.... EX POND - PRE
Page 3.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Elevation Planimeter Area Al+A2+sgr(Al*A2) Volume Volume Sum
(ft) (sq.in) (sq.ft) (sq.ft)
-
--- (cu.ft) (cu.ft)
-----------------------
------------
366.00 ---------------------
----- 26160 -----------
-
0 0 0
367.00 ----- 26160 78480 26160 26160
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-EL1) * (Areal + Area2 + sq.rt.(Areal*Area2))
where: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for EL1, EL2, respectively
Volume = Incremental volume between EL1 and EL2
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:08 AM 10/7/2010
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0
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Town Hall Common
Total
Depth Rainfall
Return Event in Type RN
-- F ID
---------
------------
1 ------
2.8400 ----------
Synthetic ------
Curve -----
TypeII 24hr
2 3.4300 Synthetic Curve TypeII 24hr
10 4.9600 Synthetic Curve TypeII 24hr
100 7.3000 Synthetic Curve TypeII 24hr
WQ Vol 1.0000 Synthetic Curve TypeII 24hr
25 5.8600 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
•
Return HYG Vol
Node ID Type Event cu.ft Trun
---------
COMBINE ----- --- ----
JCT ------
1 ----------
36397
COMBINE JCT 2 45503
COMBINE JCT 10 69426
COMBINE JCT 100 106433
COMBINE JCT 1 9257
COMBINE JCT 25 83620
COMBINE PT JCT 1 36178
COMBINE PT JCT 2 45208
COMBINE PT JCT 10 68923
COMBINE PT JCT 100 105598
COMBINE PT JCT 1 9221
COMBINE PT JCT 25 82990
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
- -------- ------------
---------
725.00 -------
6.73
724.00 9.26
723.00 16.19
723.00 27.49
728.00 .80
723.00 20.48
725.00 6.69
724.00 9.21
723.00 16.11
723.00 27.36
729.00 .80
723.00 20.39
•
S/N:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
------ cu.ft
- Trun

*CRAVEN - PRE
JCT
1 ---------
23340
*CRAVEN - PRE JCT 2 31610
*CRAVEN - PRE JCT 10 54470
*CRAVEN - PRE JCT 100 91385
*CRAVEN - PRE JCT 1 2557
*CRAVEN - PRE JCT 25 68481
CRAVEN - PRE AREA 1 23340
CRAVEN - PRE AREA 2 31610
CRAVEN - PRE AREA 10 54470
CRAVEN - PRE AREA 100 91385
CRAVEN - PRE AREA 1 2557
CRAVEN - PRE AREA 25 68481
• *CRAVEN-POST JCT 1 28814 R
CRAVEN-POST JCT 2 42116 R
*CRAVEN-POST JCT 10 78814 R
*CRAVEN-POST JCT 100 137801 R
*CRAVEN-POST JCT 1 4109
*CRAVEN-POST JCT 25 101228 R
EX POND - PREIN POND 1 34946
EX POND - PREIN POND 2 43430
EX POND - PREIN POND 10 65563
EX POND - PREIN POND 100 99563
EX POND - PREIN POND 1 9196
EX POND - PREIN POND 25 78627
EX POND - PREOUT POND 1 34923
EX POND - PREOUT POND 2 43408
EX POND - PREOUT POND 10 65540
EX POND - PREOUT POND 100 99541
EX POND - PREOUT POND 1 9174
EX POND - PREOUT POND 25 78604
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
721.00 --------
8.26 -------- ------------
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
740.00 1.85
725.00 6.52
723.00 18.44
720.00 41.36
1001.00 .04
721.00 32.69
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494
•
S/N:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event cu.ft Trun min cfs
-
---- ft cu.ft
-------- ------------
-----------------
EX POND-POST IN ----
POND ------
1 ---------- --
34946 ---------
715.00 --
-
14.09
EX POND-POST IN POND 2 43430 715.00 17.28
EX POND-POST IN POND 10 65563 715.00 25.50
EX POND-POST IN POND 100 99563 715.00 37.95
EX POND-POST IN POND 1 9196 715.00 3.95
EX POND-POST IN POND 25 78627 715.00 30.30
EX POND-POST OUT POND 1 34923 724.00 6.52 366.48 12652
EX POND-POST OUT POND 2 43408 723.00 8.96 366.56 14754
EX POND-POST OUT POND 10 65540 722.00 15.63 366.74 19255
EX POND-POST OUT POND 100 99541 722.00 26.46 366.94 24585
EX POND-POST OUT POND 1 9174 728.00 .80 366.15 4010
EX POND-POST OUT POND 25 78604 722.00 19.75 366.82 21494
• EXPOND OUT-PRE JCT 1 34923 724.00 6.52
EXPOND OUT-PRE JCT 2 43407 723.00 8.96
EXPOND OUT-PRE JCT 10 65540 722.00 15.63
EXPOND OUT-PRE JCT 100 99541 722.00 26.46
EXPOND OUT-PRE JCT 1 9173 728.00 .80
EXPOND OUT-PRE JCT 25 78604 722.00 19.75
EXPONDOUT-POST JCT 1 34923 724.00 6.52
EXPONDOUT-POST JCT 2 43407 723.00 8.96
EXPONDOUT-POST JCT 10 65540 722.00 15.63
EXPONDOUT-POST JCT 100 99541 722.00 26.46
EXPONDOUT-POST JCT 1 9173 728.00 .80
EXPONDOUT-POST JCT 25 78604 722.00 19.75
*SUB01-POST JCT 1 2998 716.00 1.28
*SUB01-POST JCT 2 4189 716.00 1.81
*SUB01-POST JCT 10 7573 715.00 3.27
*SUBO1-POST JCT 100 13175 715.00 5.61
*SUBO1-POST JCT 1 221 721.00 .06
*SUB01-POST JCT 25 9686 715.00 4.16
u
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:13 PM 10/15/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
-- cu.ft Trun

SUB01-POST
AREA ----
1 ----------
2998 --
SUB01-POST AREA 2 4189
SUB01-POST AREA 10 7573
SUB01-POST AREA 100 13175
SUB01-POST AREA 1 221
SUB01-POST AREA 25 9686
SUB01-PRE AREA 1 4887
SUB01-PRE AREA 2 7006
SUB01-PRE AREA 10 13160
SUB01-PRE AREA 100 23562
SUB01-PRE AREA 1 242
SUB01-PRE AREA 25 17060
• *SUB01-PRE JCT 1 4887
*SUB01-PRE JCT 2 7006
*SUB01-PRE JCT 10 13160
*SUB01-PRE JCT 100 23562
*SUB01-PRE JCT 1 242
*SUB01-PRE JCT 25 17060
SUB02-BYPASS AREA 1 626
SUB02-BYPASS AREA 2 906
SUB02-BYPASS AREA 10 1725
SUB02-BYPASS AREA 100 3120
SUB02-BYPASS AREA 1 4
SUB02-BYPASS AREA 25 2247
*SUB02-POST JCT 1 8672 R
*SUB02-POST JCT 2 14994 R
*SUB02-POST JCT 10 32402 R
*SUB02-POST JCT 100 60072 R
*SUB02-POST JCT 1 2624 R
*SUB02-POST JCT 25 42943 R
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
716.00 -------- -------- ------------
1.28
716.00 1.81
715.00 3.27
715.00 5.61
721.00 .06
715.00 4.16
730.00 1.20
730.00 1.76
729.00 3.37
727.00 6.04
737.00 .01
729.00 4.38
730.00 1.20
730.00 1.76
729.00 3.37
727.00 6.04
737.00 .01
729.00 4.38
716.00 .26
716.00 .39
715.00 .74
715.00 1.34
723.00 .00
715.00 .97
716.00 .31
716.00 .44
722.00 2.43
721.00 10.91
905.00 .02
725.00 7.11
•
S/N:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event cu.ft Trun
--------- --
---------------
*SUB02-PRE -- ----
JCT ------
1 -
5772
*SUB02-PRE JCT 2 8351
*SUB02-PRE JCT 10 15897
*SUB02-PRE JCT 100 28747
*SUB02-PRE JCT 1 243
*SUB02-PRE JCT 25 20706
SUB02-PRE AREA 1 5772
SUB02-PRE AREA 2 8351
SUB02-PRE AREA 10 15897
SUB02-PRE AREA 100 28747
SUB02-PRE AREA 1 243
SUB02-PRE AREA 25 20706
• SUB03-POST AREA 1 4548
SUB03-POST AREA 2 6207
SUB03-POST AREA 10 10821
SUB03-POST AREA 100 18317
SUB03-POST AREA 1 455
SUB03-POST AREA 25 13662
*SUB03-POST JCT 1 4548
*SUB03-POST JCT 2 6207
*SUB03-POST JCT 10 10821
*SUB03-POST JCT 100 18317
*SUB03-POST JCT 1 455
*SUB03-POST JCT 25 13662
SUB03-PRE AREA 1 7225
SUB03-PRE AREA 2 10359
SUB03-PRE AREA 10 19457
SUB03-PRE AREA 100 34838
SUB03-PRE AREA 1 358
SUB03-PRE AREA 25 25225
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
------ -------- ------------
---------
748.00 --
.85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
748.00 .85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
716.00 1.96
715.00 2.68
715.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
716.00 1.96
715.00 2.68
715.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
748.00 1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
is
SIN:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
----- cu.ft Trun

*SUB03-PRE
JCT -
1 ---------- --
7225
*SUB03-PRE JCT 2 10359
*SUB03-PRE JCT 10 19457
*SUB03-PRE JCT 100 34838
*SUB03-PRE JCT 1 358
*SUB03-PRE JCT 25 25225
SUB04-POST AREA 1 821
SUB04-POST AREA 2 1147
SUB04-POST AREA 10 2074
SUB04-POST AREA 100 3609
SUB04-POST AREA 1 43
SUB04-POST AREA 25 2653
• *SUB04-POST JCT 1 821
'SUB04-POST JCT 2 1147
*SUB04-POST JCT 10 2074
*SUB04-POST JCT 100 3609
*SUB04-POST JCT 1 43
*SUB04-POST JCT 25 2653
SUB04-PRE AREA 1 2931
SUB04-PRE AREA 2 4202
SUB04-PRE AREA 10 7895
SUB04-PRE AREA 100 14136
SUB04-PRE AREA 1 144
SUB04-PRE AREA 25 10235
*SUB04-PRE JCT 1 2931
*SUB04-PRE JCT 2 4202
*SUB04-PRE JCT 10 7895
*SUB04-PRE JCT 100 14136
*SUB04-PRE JCT 1 144
*SUB04-PRE JCT 25 10235
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
-
--------
---------
748.00 -------- -------- -
-
-
1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
•
S/N:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID Type Event cu.ft Trun min
---------------
*SUB05-PRE -- ----
JCT ------
1 ---------- --
5648 ---------
749.00
*SUB05-PRE JCT 2 8139 747.00
*SUB05-PRE JCT 10 15401 747.00
*SUB05-PRE JCT 100 27729 747.00
*SUB05-PRE JCT 1 255 762.00
*SUB05-PRE JCT 25 20019 747.00
SUB05A-PRE AREA 1 3066 756.00
SUB05A-PRE AREA 2 4437 756.00
SUB05A-PRE AREA 10 8447 756.00
SUB05A-PRE AREA 100 15276 756.00
SUB05A-PRE AREA 1 128 788.00
SUB05A-PRE AREA 25 11002 756.00
• SUB05B-PRE AREA 1 2582 742.00
SUB05B-PRE AREA 2 3702 742.00
SUB05B-PRE AREA 10 6955 742.00
SUB05B-PRE AREA 100 12453 742.00
SUB05B-PRE AREA 1 127 749.00
SUB05B-PRE AREA 25 9017 742.00
SUB06-POST AREA 1 2016 716.00
SUB06-POST AREA 2 3002 716.00
SUB06-POST AREA 10 5960 716.00
SUB06-POST AREA 100 11117 715.00
SUB06-POST AREA 1 44 801.00
SUB06-POST AREA 25 7878 715.00
*SUB06-POST JCT 1 2016 716.00
*SUB06-POST JCT 2 3002 716.00
*SUB06-POST JCT 10 5960 716.00
*SUB06-POST JCT 100 11117 715.00
*SUB06-POST JCT 1 44 801.00
*SUB06-POST JCT 25 7878 715.00
•
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
.74
1.10
2.18
3.96
.01
2.85
.36
.55
1.09
2.00
.00
1.43
.41
.61
1.19
2.14
.00
1.55
.81
1.26
2.57
4.80
.00
3.40
.81
1.26
2.57
4.80
.00
3.40
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:13 PM 10/15/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event cu.ft
---------- Trun
--
---------------
SUB06-PRE -- ----
AREA ------
1 11447
SUB06-PRE AREA 2 16560
SUB06-PRE AREA 10 31522
SUB06-PRE AREA 100 57002
SUB06-PRE AREA 1 483
SUB06-PRE AREA 25 41059
*SUB06-PRE JCT 1 11447
*SUB06-PRE JCT 2 16560
*SUB06-PRE JCT 10 31522
*SUB06-PRE JCT 100 57002
*SUB06-PRE JCT 1 483
*SUB06-PRE JCT 25 41059
• *SUB07-POST JCT 1 40513 R
"SUB07-POST JCT 2 52807 R
*SUB07-POST JCT 10 86036 R
*SUB07-POST JCT 100 138929 R
*SUB07-POST JCT 1 9933
*SUB07-POST JCT 25 106168 R
*SUB07-PRE JCT 1 39063
*SUB07-PRE JCT 2 50114
*SUB07-PRE JCT 10 80555
*SUB07-PRE JCT 100 130117
*SUB07-PRE JCT 1 9221
*SUB07-PRE JCT 25 99292
SUB07A-POST AREA 1 1229
SUB07A-POST AREA 2 2090
SUB07A-POST AREA 10 4955
SUB07A-POST AREA 100 10443
SUB07A-POST AREA 1 0
SUB07A-POST AREA 25 6944
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
--- -------- ------------
---------
747.00 -----
1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
724.00 6.98
723.00 9.72
723.00 18.50
721.00 39.73
728.00 .80
723.00 27.09
726.00 7.07
725.00 10.04
725.00 18.71
724.00 33.21
730.00 .80
724.00 24.10
721.00 .42
720.00 .77
716.00 2.04
716.00 4.49
1.00 .00
716.00 2.94
•
S/N:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event cu.ft Trun
-- --
---------------
SUB07A-PRE -- ----
AREA ------
1 --------
2884
SUB07A-PRE AREA 2 4906
SUB07A-PRE AREA 10 11632
SUB07A-PRE AREA 100 24519
SUB07A-PRE AREA 1 0
SUB07A-PRE AREA 25 16302
SUB07B-POST AREA 1 1474
SUB07B-POST AREA 2 2096
SUB07B-POST AREA 10 3887
SUB07B-POST AREA 100 6892
SUB07B-POST AREA 1 83
SUB07B-POST AREA 25 5016
• SUB07B-PRE AREA 1 1256
SUB07B-PRE AREA 2 1800
SUB07B-PRE AREA 10 3383
SUB07B-PRE AREA 100 6058
SUB07B-PRE AREA 1 48
SUB07B-PRE AREA 25 4386
SUB07C-POST AREA 1 34946
SUB07C-POST AREA 2 43430
SUB07C-POST AREA 10 65563
SUB07C-POST AREA 100 99563
SUB07C-POST AREA 1 9196
SUB07C-POST AREA 25 78627
SUB07C-PRE AREA 1 34946
SUB07C-PRE AREA 2 43430
SUB07C-PRE AREA 10 65563
SUB07C-PRE AREA 100 99563
SUB07C-PRE AREA 1 9196
SUB07C-PRE AREA 25 78627
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
-- -------- ------------
---------
731.00 ------
.48
731.00 1.00
728.00 2.83
728.00 6.38
1.00 .00
728.00 4.13
734.00 .29
734.00 .42
734.00 .80
734.00 1.43
740.00 .00
734.00 1.04
737.00 .24
737.00 .36
733.00 .69
733.00 1.25
732.00 .00
733.00 .90
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:13 PM 10/15/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-
----------
----- Type Event cu.ft Trun
-
TO WETLAND
#1 ----
AREA ------
1 ----------
21481
TO WETLAND #1 AREA 2 27849
TO WETLAND #1 AREA 10 44859
TO WETLAND #1 AREA 100 71505
TO WETLAND #1 AREA 1 3743
TO WETLAND #1 AREA 25 55049
TO WETLAND #2 AREA 1 18259
TO WETLAND #2 AREA 2 24012
TO WETLAND #2 AREA 10 39542
TO WETLAND #2 AREA 100 64091
TO WETLAND #2 AREA 1 2755
TO WETLAND #2 AREA 25 48910
• TO WETLAND #3 AREA 1 23025
TO WETLAND #3 AREA 2 30951
TO WETLAND #3 AREA 10 52722
TO WETLAND #3 AREA 100 87679
TO WETLAND #3 AREA 1 2748
TO WETLAND #3 AREA 25 66009
TO WETLAND #4 AREA 1 7202
TO WETLAND #4 AREA 2 9610
TO WETLAND #4 AREA 10 16185
TO WETLAND #4 AREA 100 26684
TO WETLAND #4 AREA 1 932
TO WETLAND #4 AREA 25 20181
WETLAND #1 IN POND 1 21481
WETLAND #1 IN POND 2 27849
WETLAND #1 IN POND 10 44859
WETLAND #1 IN POND 100 71505
WETLAND #1 IN POND 1 3743
WETLAND #1 IN POND 25 55049
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
-
---
---------
715.00 -------- -------- -----
-
--
9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
715.00 3.11
715.00 4.14
715.00 6.88
715.00 11.07
720.00 .35
715.00 8.49
715.00 9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
•
SIN:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
---------
---
----- Type
---- Event
------ cu.ft
---------- Trun
--
WETLAND #1 OUT POND 1 8047 R
WETLAND #1 OUT POND 2 14089 R
WETLAND #1 OUT POND 10 30678 R
WETLAND #1 OUT POND 100 56953 R
WETLAND #1 OUT POND 1 2621 R
WETLAND #1 OUT POND 25 40697 R
WETLAND #2 IN POND 1 18259
WETLAND #2 IN POND 2 24012
WETLAND #2 IN POND 10 39542
WETLAND #2 IN POND 100 64091
WETLAND #2 IN POND 1 2755
WETLAND #2 IN POND 25 48910
WETLAND #2 OUT POND 1 11946 R
•
WETLAND #2 OUT POND 2 17529 R
WETLAND #2 OUT POND 10 32763 R
WETLAND #2 OUT POND 100 57066 R
WETLAND #2 OUT POND 1 1964 R
WETLAND #2 OUT POND 25 42012 R
WETLAND #3 IN POND 1 23025
WETLAND #3 IN POND 2, 30951
WETLAND #3 IN POND 10 52722
WETLAND #3 IN POND 100 87679
WETLAND #3 IN POND 1 2748
WETLAND #3 IN POND 25 66009
WETLAND #3 OUT POND 1 16870 R
WETLAND #3 OUT POND 2 24589 R
WETLAND #3 OUT POND 10 46052 R
WETLAND #3 OUT POND 100 80736 R
WETLAND #3 OUT POND 1 2144
WETLAND #3 OUT POND 25 59217 R
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
------------
---------
1139.00 --------
.12 --------
371.89 17235
825.00 .42 372.03 18803
736.00 2.22 372.63 25503
724.00 10.06 373.52 36042
1031.00 .03 370.39 2661
725.00 6.79 372.99 29753
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
760.00 .54 348.93 10458
732.00 1.54 349.18 12514
726.00 4.42 350.08 19931
724.00 11.20 351.00 27698
1165.00 .02 347.80 1948
723.00 10.34 350.38 22382
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
734.00 1.44 347.38 11206
725.00 5.10 347.77 13746
722.00 15.00 348.63 19407
719.00 30.41 349.10 22563
1265.00 .02 345.85 1837
719.00 22.97 348.80 20577

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:13 PM 10/15/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event cu.ft Trun
---------
WETLAND ----
#4 ----
IN ----
POND ------
1 ----------
7202
WETLAND #4 IN POND 2 9610
WETLAND #4 IN POND 10 16185
WETLAND #4 IN POND 100 26684
WETLAND #4 IN POND 1 932
WETLAND #4 IN POND 25 20181
WETLAND #4 OUT POND 1 2889 R
WETLAND #4 OUT POND 2 5216 R
WETLAND #4 OUT POND 10 11657 R
WETLAND #4 OUT POND 100 22053 R
WETLAND #4 OUT POND 1 677
WETLAND #4 OUT POND 25 15606 R
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft
- cu.ft
------------
---------
715.00 --------
3.11 -------
715.00 4.14
715.00 6.88
715.00 11.07
720.00 .35
715.00 8.49
1010.00 .05 351.67 5557
792.00 .20 351.78 6014
730.00 1.02 352.40 8562
719.00 9.26 352.80 10295
909.00 .01 350.27 644
723.00 4.73 352.67 9728

•
SIN:
Bentley PondPack (10.00.027.00)
1:13 PM
Bentley Systems, Inc.
10/15/2010
•

POST-DEVELOPMENT HYDROLOGIC
CALCULATIONS
0
0
TOWN HALL COMMONS
PLT-10000
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TOWN HALL COMMONS RUNOFF VOLUME COMPUTATIONS
PLT-10000 (Using SCS CNMethod: Input Data)
• 'FABLE l: PRE-DEVELOPMENT COVER CONDITIONS
J. FINCH, PE
10/11/2010
Cover Cond itions [acres]
Facility ID Area [acres] - ----
Impervious Wooded Open Pond
*Theoretical - To Wetland #1 3.22 0.00 3.22 0.00 0.00
*Theoretical - To Wetland #2 3.00 0.05 2.93 0.02 0.00
*Theoretical - To Wetland #3 4.36 0.00 4.36 0.00 0.00
t
*Theoretical - To Wetland #4 1.30 0.00 1.30 0.00 0.00
Totals = 11.89 0.05 11.82 0.02 I 0.00
* Theoretical = For the purposes of the pre-development runoff volume calculations, the post-development
drainage areas to the proposed wetlands were overlain onto the pre-development topo and a corresponding
SCS CN extracted.
TABLE 2: POST-DEVELOPMENT COVER CONDITIONS
Facility ID I Area [acres]
To Wetland #1 3.22
To Wetland #2 3.00
To Wetland #3 4.36
__ ___ -
To Wetland 94 -1.3-
Totals = 11.89
•
Cover Conditions
[acres]
Impervious _
Wooded Open Pond
1
63 0
00 41
1 0.18
. . .
1.26 010 1.49 0.15
1.23 000 301 0.12
0.68 0.00 0.56 0.06

4.81 0.10 6.47 0.51
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TOWN HALL COMMONS HYDROLOGIC CALCULATIONS J. FINCH, PE
PLT-10000 Post-development - Subbasin #1 10/4/2010

Assume:
C7
Total Roadway Impervious Area = 871 SF
= 0.02 acres
Total ROW Sidewalk Impervious Area = 322 SF
= 0.01 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.03 -
Onsite open 80 0.56 Assume good condition
Onsite wooded 77 0.14 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area =
Composite SCS CN =
% Impervious =
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
0.73 acres
0.0011 sq.mi.
80
3.8%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes (= 0.29*SCS Lag)

Type.... Runoff CN-Area
Name.... SUB01-POST
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
80 .730 80.00
COMPOSITE AREA & WEIGHTED CN ---> .730 80.00 (80)
...........................................................................
...........................................................................
•
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB01-POST
Page 1.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
-------------------------
-------------------------
•
•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS
PLT-10000 Post-development - Subbasin #2 - To Wetland #1
•
ID
Assume:
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG 'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 6.5%
HSG'D' = 93.5%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
Total Single-Family Residential Lots = 15.75 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 47,250 SF
= 1.08 acres
Total Roadway Impervious Area = 18,144 SF
= 0.42 acres
Total ROW Sidewalk Impervious Area = 5,793 SF
= 0.13 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 1.63 -
Onsite open 80 1.41 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.18 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
J. FINCH, PE
10/4/2010
Total area = 3.22 acres
0.0050 sq.mi.
Composite SCS CN = 90
% Impervious = 50.7%
B. Time of Concentration Information
* "Time of concentration was assumed to be 5 minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS Lag)
Type.... Runoff CN-Area
Name.... TO WETLAND #1
Page 2.09
. File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
•
•
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
90 3.220 90.00
COMPOSITE AREA & WEIGHTED CN ---> 3.220 90.00 (90)
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... TO WETLAND #1
Page 1.17
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 5.00 min

•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume.
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 73.7%
HSG'D' = 26.3%
Cover Condition SCS CN Comments
Impervious 98
Open 76 Assume good condition
Wooded 72 Assume good condition
•
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 76 0.19 Assume good condition
Onsite wooded 72 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 76 0.00 Assume good condition
Offsite wooded 72 0.00 Assume good condition
Offsite and 100 0.00 -
Total area =
Composite SCS CN =
% Impervious =
HYDROLOGIC CALCULATIONS
Post-development - Subbasin #2 Bypass
0.19 acres
0.0003 sq.mi.
76
0.0%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
J. FINCH, PE
10/4/2010
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes (= 0.29*SCS Lag)
0
Type.... Runoff CN-Area
Name.... SUB02-BYPASS
Page 2.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
76 .190 76.00
COMPOSITE AREA & WEIGHTED CN ---> .190 76.00 (76)
...........................................................................
...........................................................................
•
•
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB02-BYPASS
Page 1.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
HYDROLOGIC CALCULATIONS
Post-development - Subbasin #3
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume.
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
•
•
Total Single-Family Residential Lots = 1.50 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 4,500 SF
= 0.10 acres
Total Roadway Impervious Area = 1,741 SF
= 0.04 acres
Total ROW Sidewalk Impervious Area = 662 SF
= 0.02 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.16 -
Onsite open 80 0.79 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area = 0.95 acres
0.0015 sq.mi.
Composite SCS CN = 83
% Impervious = 16.7%
B. Time of Concentration Information
***Time ofconcentration was assumed to be 5 minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS La
J. FINCH, PE
10/4/2010
Type.... Runoff CN-Area
Name.... SUB03-POST
Page 2.03
0. File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C RUC CN
-------------------------------- ---- --------- ----- ----- ------
83 .950 83.00
COMPOSITE AREA & WEIGHTED CN ---> .950 83.00 (83)
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB03-POST
Page 1.05
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 5.00 min
-------------------------
-------------------------

•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
HYDROLOGIC CALCULATIONS
Post-development - Subbasin #4
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume.
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG 'C' = 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown

Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.20 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.00 Assume good condition
Offsite wooded 77 0.00 Assume good condition
Offsite and 100 0.00 -
Total area =
Composite SCS CN =
% Impervious =
J. FINCH, PE
10/4/2010
0.20 acres
0.0003 sq.mi.
80
0.0%
B. Time of Concentration Information
***Time of concentration was assumed to be S minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes (= 0.29*SCS Lag)
0
Type.... Runoff CN-Area
Name.... SUB04-POST
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
•
Soil/Surface Description
--------------------------------
Page 2.04
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
80 .200 80.00
COMPOSITE AREA & WEIGHTED CN ---> .200 80.00 (80)
•
S/N:
Bentley PondPack (10.00.027.00)
11:19 AM
Bentley Systems, Inc.
10/7/2010
Type.... Tc Calcs
Name.... SUB04-POST
Page 1.07
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
-------------------------
-------------------------
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
Aliftm
•
•
Assume:
HYDROLOGIC CALCULATIONS
Post-development - To Wetland #2
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG 'A' = 0.0%
HSG 'B' = 0.0%
HSG'C' = 3.7%
HSG'D' = 96.3%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown
Total Single-Family Residential Lots = 10.50 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 31,500 SF
= 0.72 acres
Total Roadway Impervious Area = 17,477 SF
= 0.40 acres
Total ROW Sidewalk Impervious Area = 5,843 SF
= 0.13 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 1.26 -
Onsite open 80 1.48 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.15 -
Offsite impervious 98 0.00 -
Offsite open 80 0.01 Assume good condition
Offsite wooded 77 0.10 Assume good condition
Offsite and 100 0.00 -
J. FINCH, PE
10/4/2010
Total area = 3.00 acres
0.0047 sq.mi.
Composite SCS CN = 88
% Impervious = 42.0%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS Lag)
Type.... Runoff CN-Area
Name.... TO WETLAND #2
•
•
•
Page 2.10
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C RUC CN
---- --------- ----- ----- ------
88 3.000 88.00
COMPOSITE AREA & WEIGHTED CN ---> 3.000 88.00 (88)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... TO WETLAND #2
Page 1.19
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0 TIME OF CONCENTRATION CALCULATOR

Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min

•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS
PLT-10000 Post-development - To Wetland #3
0 1 " '
Assume:
•
J
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG 'A' = 0.0%
HSG'B' = 0.0%
HSG'C' = 9.6%
HSG'D' = 90.4%
Cover Condition SCS CN Comments
Impervious 98
Open 79 Assume good condition
Wooded 76 Assume good condition
J. FINCH, PE
10/4/2010
A. Watershed Breakdown
Total Single-Family Residential Lots = 6 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 18,000 SF
= 0.41 acres
Total Roadway Impervious Area = 6,953 SF
= 0.16 acres
Total ROW Sidewalk Impervious Area = 2,395 SF
= 0.05 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.63 -
Onsite open 79 1.06 Assume good condition
Onsite wooded 76 0.00 Assume good condition
Onsite and 100 0.08 -
Offsite impervious 98 0.61 Includes Measured & 10% impervious on offsite area
Offsite open 79 1.95 Assume good condition
Offsite wooded 76 0.00 Assume good condition
Offsite and 100 0.04 -
Total area = 4.36 acres
0.0068 sq.mi.
Composite SCS CN = 85
% Impervious = 28.3%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS Lag)
Type.... Runoff CN-Area
Name.... TO WETLAND #3

•
•
Page 2.11
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
85 4.360 85.00
COMPOSITE AREA & WEIGHTED CN ---> 4.360 85.00 (85)
SIN:
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Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... TO WETLAND #3
Page 1.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
-------------------------
-------------------------

•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000 .
•
Assume:
HYDROLOGIC CALCULATIONS
Post-development - Subbasin #6
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 30.1%
HSG'C' = 0.0%
HSG'D' = 69.9%
Cover Condition SCS CN Comments
Impervious 98
Open 74 Assume good condition
Wooded 70 Assume good condition
A. Watershed Breakdown
•
Total Single-Family Residential Lots = 0.25 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 750 SF
= 0.02 acres
Total Roadway Impervious Area = 0 SF
= 0.00 acres
Total ROW Sidewalk Impervious Area = 0 SF
= 0.00 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.02 _
Onsite open 74 0.38 Assume good condition
Onsite wooded 70 0.33 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 74 0.00 Assume good condition
Offsite wooded 70 0.00 Assume good condition
Offsite and 100 0.00 -
J. FINCH, PE
10/7/2010
Total area = 0.73 acres
0.0011 sq.mi.
Composite SCS CN = 73
% Impervious = 2.4%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
•
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS Lag)
Type.... Runoff CN-Area
Name.... SUB06-POST

•
•
Page 2.05
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
73 .730 73.00
COMPOSITE AREA & WEIGHTED CN ---> .730 73.00 (73)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB06-POST
Page 1.09
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 5.00 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS
PLT-10000
Assume.
HYDROLOGIC CALCULATIONS
Post-development - To Wetland #4
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 55.4%
HSG'C' = 0.0%
HSG'D' = 44.6%
Cover Condition SCS CN Comments
Impervious 98
Open 69 Assume good condition
Wooded 65 Assume good condition
J. FINCH, PE
10/4/2010
A. Watershed Breakdown
•
Total Single-Family Residential Lots = 6 Lots
Impervious Per Single-Family Lot (Inc House, Patio, D/W, S/W) = 3,000 SF
Total Impervious Area From Single-Family Lots = 18,000 SF
= 0.41 acres
Total Roadway Impervious Area = 10,497 SF
= 0.24 acres
Total ROW Sidewalk Impervious Area = 751 SF
= 0.02 acres
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.67 -
Onsite open 69 0.46 Assume good condition
Onsite wooded 65 0.00 Assume good condition
Onsite and 100 0.06 -
Offsite impervious 98 0.01 -
Offsite oven 69 0.10 Assume good condition
Offsite wooded 65 0.00 Assume good condition
Offsite and 100 0.00 -
Total area =
Composite SCS CN =
% Impervious =
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes
•
1.30 acres
0.0020 sq.mi.
86
514%
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes (= 0.29*SCS La
Type.... Runoff CN-Area
Name.... TO WETLAND #4
Page 2.12
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
C
•
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
86 1.300 86.00
COMPOSITE AREA & WEIGHTED CN ---> 1.300 86.00 (86)
S/N:
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Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... TO WETLAND #4
Page 1.23
0 File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
is
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
•
TOWN HALL COMMONS
PLT-10000
HYDROLOGIC CALCULATIONS
Post-development - Subbasin VA
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Assume:
HSG'A' = 0.0%
HSG'B' = 75.0%
HSG'C' = 0.0%
HSG'D' = 25.0%
Cover Condition SCS CN Comments
Impervious 98
Open 66 Assume good condition
Wooded 61 Assume good condition
•
A. Watershed Breakdown
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 66 0.48 Assume good condition
Onsite wooded 61 0.44 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 66 0.00 Assume good condition
Offsite wooded 61 0.00 Assume good condition
Offsite and 100 0.00 -
Total area =
Composite SCS CN =
% Impervious =
0.92 acres
0.0014 sq.mi.
63
0.0%
B. Time of Concentration Information
***Time of concentration was assumed to be S minutes
J. FINCH, PE
10/7/2010
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes (= 0 29*SCS Lag)

Type.... Runoff CN-Area
Name.... SUB07A-POST
C
•
0-
Page 2.06
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
63 .920 63.00
COMPOSITE AREA & WEIGHTED CN ---> .920 63.00 (63)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB07A-POST
•
Page 1.11
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
Total Tc: 5.00 min
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS J. FINCH, PE
PLT-10000 Post-development - Subbasin #7B 10/4/2010
1. SCS CURVE NUMBERS
•
Assume:
HSG'A' = 0.0%
HSG'B' = 0.0%
HSG'C'= 0.0%
HSG'D' = 100.0%
Cover Condition SCS CN Comments
Impervious 98 -
Open 80 Assume good condition
Wooded 77 Assume good condition
H. POST-DEVELOPMENT
A. Watershed Breakdown
E
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.04 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 0.00 -
Offsite open 80 0.05 Assume good condition
Offsite wooded 77 0.31 Assume good condition
Offsite pond 100 0.00 -
Total area = 0.40 acres
0.0006 sq.mi.
Composite SCS CN = 78
% Impervious = 0.0%
B. Time of Concentration Information
***Time of concentration is calculated using the SCS Segme ntal Approach (TR-55).
Segment 1: Overland Flow
Length = 200 ft
Height = 4.05 ft
Slope = 0.0203 ft/ft
Manning's n = 0.40 Woods - Light Underbrush
P (2-year/24-hour) = 3.43 inches (RDU, NC)
Segment Time = 35.93 minutes
Segment 2: Concentrated Flow
Length = 118 ft
Height = 5.95 ft
Slope = 0.0504 ft/ft
Paved ? = No
Velocity = 3.62 ft/sec
Segment Time = 0.54 minutes
Time of Concentration = 36.48 minutes
SCS Lag Time = 21.89 minutes (SCS Lag = 0.6* Tc)
Time Increment = 6.35 minutes (= 0.29*SCS Lag)
is
Type.... Runoff CN-Area
Name.... SUB07B-POST

11
•
Page 2.07
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
78 .400 78.00
COMPOSITE AREA & WEIGHTED CN ---> .400 78.00 (78)
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB07B-POST

Page 1.13
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 36.48 min
------------------------------------------------------------------------
Total Tc: 36.48 min
is
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
TOWN HALL COMMONS HYDROLOGIC CALCULATIONS J. FINCH, PE
PLT-10000 Post-development - Subbasin #7C 10/4/2010

Assume:
HSG Impervious Open Wooded
A 98 39 30
B 98 61 55
C 98 74 70
D 98 80 77
HSG'A' = 0.0%
HSG'B' = 2.0%
HSG'C' = 0.0%
HSG'D' = 98.0%
Cover Condition SCS CN Comments
Impervious 98
Open 80 Assume good condition
Wooded 77 Assume good condition
A. Watershed Breakdown

Contributing Area SCS CN Area [acres] Comments
Onsite impervious 98 0.00 -
Onsite open 80 0.00 Assume good condition
Onsite wooded 77 0.00 Assume good condition
Onsite and 100 0.00 -
Offsite impervious 98 2.96 -
Offsite open 80 0.15 Assume good condition
Offsite wooded 77 0.31 Assume good condition
Offsite and 100 0.60 -
Total area = 4.02 acres
0.0063 sq.mi.
Composite SCS CN = 96
% Impervious = 73.6%
B. Time of Concentration Information
***Time of concentration was assumed to be 5 minutes due to amount of existing offsite impervious
Time of Concentration = 5.00 minutes
SCS Lag Time = 3.00 minutes (SCS Lag = 0.6* Tc)
Time Increment = 0.87 minutes = 0.29*SCS Lag)
C. Reach Information
Concentrated Flow

Length =
Height =
Slope =
Paved ? =
Velocity =
Segment Time =
203
7
0.0345
No
3.00
1.13
ft
ft
ft/ft
ft/sec
minutes
Type.... Runoff CN-Area
Name.... SUB07C-POST
Page 2.08
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
RUNOFF CURVE NUMBER DATA
Soil/Surface Description
--------------------------------
Impervious
Area Adjustment Adjusted
CN acres %C %UC CN
---- --------- ----- ----- ------
96 4.020 96.00
COMPOSITE AREA & WEIGHTED CN ---> 4.020 96.00 (96)

0-
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Tc Calcs
Name.... SUB07C-POST
Page 1.15
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: 5.00 min
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: 5.00 min
-------------------------
-------------------------
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
•
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0
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Project3\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
W Wfilu. OMM$44 't
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Town Hall Common
Total
Depth
Return Event in
1 2.8400
2 3.4300
10 4.9600
100 7.3000
wQ Vol 1.0000
25 5.8600
Return HYG Vol Qpeak
Node ID
------------- Type
---- ---- Event
-- cu.ft Trun min

COMBINE
JCT ----
1 ---------- --
36397 ---------
725.00
COMBINE JCT 2 45503 724.00
COMBINE JCT 10 69426 723.00
COMBINE JCT 100 106433 723.00
COMBINE JCT 1 9257 728.00
COMBINE JCT 25 83620 723.00
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
r?
•
Rainfall
Type
----------------
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
RNF ID
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
6.73
9.26
16.19
27.49
.80
20.48
COMBINE PT JCT 1 36178 725.00 6.69
COMBINE PT JCT 2 45208 724.00 9.21
COMBINE PT JCT 10 68923 723.00 16.11
COMBINE PT JCT 100 105598 723.00 27.36
COMBINE PT JCT 1 9221 729.00 .80
COMBINE PT JCT 25 82990 723.00 20.39
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
-- cu.ft Trun

*CRAVEN - PRE
JCT ----
1 ----------
23340
*CRAVEN - PRE JCT 2 31610
*CRAVEN - PRE JCT 10 54470
*CRAVEN - PRE JCT 100 91385
*CRAVEN - PRE JCT 1 2557
*CRAVEN - PRE JCT 25 68481
CRAVEN - PRE AREA 1 23340
CRAVEN - PRE AREA 2 31610
CRAVEN - PRE AREA 10 54470
CRAVEN - PRE AREA 100 91385
CRAVEN - PRE AREA 1 2557
CRAVEN - PRE AREA 25 68481
• *CRAVEN-POST JCT 1 28814 R
*CRAVEN-POST JCT 2 42116 R
*CRAVEN-POST JCT 10 78814 R
*CRAVEN-POST JCT 100 137801 R
*CRAVEN-POST JCT 1 4109
*CRAVEN-POST JCT 25 101228 R
EX POND - PREIN POND 1 34946
EX POND - PREIN POND 2 43430
EX POND - PREIN POND 10 65563
EX POND - PREIN POND 100 99563
EX POND - PREIN POND 1 9196
EX POND - PREIN POND 25 78627
EX POND - PREOUT POND 1 34923
EX POND - PRECUT POND 2 43408
EX POND - PRECUT POND 10 65540
EX POND - PREOUT POND 100 99541
EX POND - PRECUT POND 1 9174
EX POND - PREOUT POND 25 78604
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
721.00 --------
8.26 -------- ------------
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
740.00 1.85
725.00 6.52
723.00 18.44
720.00 41.36
1001.00 .04
721.00 32.69
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
----------------- Type
---- Event
------ cu.ft Trun min cfs ft cu.ft

EX POND-POST IN
POND
1 ---------- --
34946 ---------
715.00 --------
14.09 -------- ------------
EX POND-POST IN POND 2 43430 715.00 17.28
EX POND-POST IN POND 10 65563 715.00 25.50
EX POND-POST IN POND 100 99563 715.00 37.95
EX POND-POST IN POND 1 9196 715.00 3.95
EX POND-POST IN POND 25 78627 715.00 30.30
EX POND-POST OUT POND 1 34923 724.00 6.52 366.48 12652
EX POND-POST OUT POND 2 43408 723.00 8.96 366.56 14754
EX POND-POST OUT POND 10 65540 722.00 15.63 366.74 19255
EX POND-POST OUT POND 100 99541 722.00 26.46 366.94 24585
EX POND-POST OUT POND 1 9174 728.00 .80 366.15 4010
EX POND-POST OUT POND 25 78604 722.00 19.75 366.82 21494
EXPOND OUT-PRE JCT 1 34923 724.00 6.52
•
EXPOND OUT-PRE JCT 2 43407 723.00 8.96
EXPOND OUT-PRE JCT 10 65540 722.00 15.63
EXPOND OUT-PRE JCT 100 99541 722.00 26.46
EXPOND OUT-PRE JCT 1 9173 728.00 .80
EXPOND OUT-PRE JCT 25 78604 722.00 19.75
EXPONDOUT-POST JCT 1 34923 724.00 6.52
EXPONDOUT-POST JCT 2 43407 723.00 8.96
EXPONDOUT-POST JCT 10 65540 722.00 15.63
EXPONDOUT-POST JCT 100 99541 722.00 26.46
EXPONDOUT-POST JCT 1 9173 728.00 .80
EXPONDOUT-POST JCT 25 78604 722.00 19.75
*SUBO1-POST JCT 1 2998 716.00 1.28
*SUBO1-POST JCT 2 4189 716.00 1.81
*SUBO1-POST JCT 10 7573 715.00 3.27
*SUBO1-POST JCT 100 13175 715.00 5.61
*SUB01-POST JCT 1 221 721.00 .06
*SUBO1-POST JCT 25 9686 715.00 4.16
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return
Node ID
-------------- Type
--- Event

SUB01-POST ----
AREA ------
1
SUB01-POST AREA 2
SUB01-POST AREA 10
SUB01-POST AREA 100
SUB01-POST AREA 1
SUB01-POST AREA 25
SUB01-PRE
SUB01-PRE
SUB01-PRE
SUB01-PRE
SUB01-PRE
SUB01-PRE
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
• SUB01-PRE
*SUBO1-PRE
*SUBO1-PRE
*SUBO1-PRE
*SUBO1-PRE
*SUBO1-PRE
SUB02-BYPASS
SUB02-BYPASS
SUB02-BYPASS
SUB02-BYPASS
SUB02-BYPASS
SUB02-BYPASS
*SUB02-POST
*SUB02-POST
*SUB02-POST
*SUB02-POST
*SUB02-POST
*SUB02-POST
1?
JCT
JCT
JCT
JCT
JCT
JCT
AREA
AREA
AREA
AREA
AREA
AREA
JCT
JCT
JCT
JCT
JCT
JCT
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
Max
HYG Vol Qpeak Qpeak Max WSEL Pond Storage
cu.ft
-------- Trun
-- min cfs ft cu.ft

2998 ---------
716.00 -------- -------- ------------
1.28
4189 716.00 1.81
7573 715.00 3.27
13175 715.00 5.61
221 721.00 .06
9686 715.00 4.16
4887 730.00 1.20
7006 730.00 1.76
13160 729.00 3.37
23562 727.00 6.04
242 737.00 .01
17060 729.00 4.38
4887 730.00 1.20
7006 730.00 1.76
13160 729.00 3.37
23562 727.00 6.04
242 737.00 .01
17060 729.00 4.38
626 716.00 .26
906 716.00 .39
1725 715.00 .74
3120 715.00 1.34
4 723.00 .00
2247 715.00 .97
8661 R 716.00 .31
14983 R 716.00 .44
32390 R 722.00 2.43
60061 R 721.00 10.87
2630 R 894.00 .02
42931 R 725.00 7.11
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID
----- Type Event cu.ft Trun min
-------
--
*SUB02-PRE --- ----
JCT ------
1 ---------- --
5772 ---------
748.00
*SUB02-PRE JCT 2 8351 748.00
*SUB02-PRE JCT 10 15897 747.00
*SUB02-PRE JCT 100 28747 741.00
*SUB02-PRE JCT 1 243 766.00
*SUB02-PRE JCT 25 20706 741.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
.85
1.28
2.52
4.61
.01
3.30
SUB02-PRE AREA 1 5772 748.00 .85
SUB02-PRE AREA 2 8351 748.00 1.28
SUB02-PRE AREA 10 15897 747.00 2.52
SUB02-PRE AREA 100 28747 741.00 4.61
SUB02-PRE AREA 1 243 766.00 .01
SUB02-PRE AREA 25 20706 741.00 3.30
SUB03-POST AREA 1 4548 716.00 1.96
•
SUB03-POST AREA 2 6207 715.00 2.68
SUB03-POST AREA 10 10821 715.00 4.64
SUB03-POST AREA 100 18317 715.00 7.71
SUB03-POST AREA 1 455 721.00 .16
SUB03-POST AREA 25 13662 715.00 5.82
*SUB03-POST JCT 1 4548 716.00 1.96
*SUB03-POST JCT 2 6207 715.00 2.68
*SUB03-POST JCT 10 10821 715.00 4.64
*SUB03-POST JCT 100 18317 715.00 7.71
*SUB03-POST JCT 1 455 721.00 .16
*SUB03-POST JCT 25 13662 715.00 5.82
SUB03-PRE AREA 1 7225 748.00 1.04
SUB03-PRE AREA 2 10359 748.00 1.55
SUB03-PRE AREA 10 19457 748.00 3.01
SUB03-PRE AREA 100 34838 748.00 5.41
SUB03-PRE AREA 1 358 765.00 .01
SUB03-PRE AREA 25 25225 748.00 3.92
•
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- --- Event cu.ft Trun

*SUB03-PRE -
JCT ------
1 ---------- --
7225
*SUB03-PRE JCT 2 10359
*SUB03-PRE JCT 10 19457
*SUB03-PRE JCT 100 34838
*SUB03-PRE JCT 1 358
*SUB03-PRE JCT 25 25225
SUB04-POST AREA 1 821
SUB04-POST AREA 2 1147
SUB04-POST AREA 10 2074
SUB04-POST AREA 100 3609
SUB04-POST AREA 1 43
SUB04-POST AREA 25 2653
*SUB04-POST JCT 1 821
•
*SUB04-POST JCT 2 1147
*SUB04-POST JCT 10 2074
*SUB04-POST JCT 100 3609
*SUB04-POST JCT 1 43
*SUB04-POST JCT 25 2653
SUB04-PRE AREA 1 2931
SUB04-PRE AREA 2 4202
SUB04-PRE AREA 10 7895
SUB04-PRE AREA 100 14136
SUB04-PRE AREA 1 144
SUB04-PRE AREA 25 10235
*SUB04-PRE JCT 1 2931
*SUB04-PRE JCT 2 4202
*SUB04-PRE JCT 10 7895
*SUB04-PRE JCT 100 14136
*SUB04-PRE JCT 1 144
*SUB04-PRE JCT 25 10235
Max
Qpeak Qpeak Max WSEL Pond Storage
min
- cfs ft cu.ft
--------
748.00 -------- -------- ------------
1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event cu.ft Trun

*SUB05-PRE
JCT ------
1 ---------- --
5648
*SUB05-PRE JCT 2 8139
*SUB05-PRE JCT 10 15401
*SUB05-PRE JCT 100 27729
*SUB05-PRE JCT 1 255
*SUB05-PRE JCT 25 20019
SUB05A-PRE AREA 1 3066
SUB05A-PRE AREA 2 4437
SUB05A-PRE AREA 10 8447
SUB05A-PRE AREA 100 15276
SUB05A-PRE AREA 1 128
SUB05A-PRE AREA 25 11002
SUB05B-PRE AREA 1 2582
•
SUB05B-PRE AREA 2 3702
SUB05B-PRE AREA 10 6955
SUB05B-PRE AREA 100 12453
SUB05B-PRE AREA 1 127
SUB05B-PRE AREA 25 9017
SUB06-POST AREA 1 2016
SUB06-POST AREA 2 3002
SUB06-POST AREA 10 5960
SUB06-POST AREA 100 11117
SUB06-POST AREA 1 44
SUB06-POST AREA 25 7878
*SUB06-POST JCT 1 2016
*SUB06-POST JCT 2 3002
*SUB06-POST JCT 10 5960
*SUB06-POST JCT 100 11117
*SUB06-POST JCT 1 44
*SUB06-POST JCT 25 7878
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
749.00 -------- -------- ------------
.74
747.00 1.10
747.00 2.18
747.00 3.96
762.00 .01
747.00 2.85
756.00 .36
756.00 .55
756.00 1.09
756.00 2.00
788.00 .00
756.00 1.43
742.00 .41
742.00 .61
742.00 1.19
742.00 2.14
749.00 .00
742.00 1.55
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
•
SIN:
Bentley PondPack (10.00.027.00)
11:47 AM
Bentley Systems, Inc.
10/19/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0-
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID
-------------- Type
--- ---- Event
- cu.ft Trun min

SUB06-PRE
AREA -
----
1 ---------- --
11447 ---------
747.00
SUB06-PRE AREA 2 16560 747.00
SUB06-PRE AREA 10 31522 747.00
SUB06-PRE AREA 100 57002 747.00
SUB06-PRE AREA 1 483 781.00
SUB06-PRE AREA 25 41059 747.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
1.62
2.45
4.86
8.88
.02
6.37
*SUB06-PRE JCT 1 11447 747.00 1.62
*SUB06-PRE JCT 2 16560 747.00 2.45
*SUB06-PRE JCT 10 31522 747.00 4.86
*SUB06-PRE JCT 100 57002 747.00 8.88
*SUB06-PRE JCT 1 483 781.00 .02
*SUB06-PRE JCT 25 41059 747.00 6.37
*SUB07-POST JCT 1 40513 R 724.00 6.98
•
kSUB07-POST JCT 2 52807 R 723.00 9.72
*SUB07-POST JCT 10 86036 R 723.00 18.50
*SUB07-POST JCT 100 138929 R 721.00 39.73
*SUB07-POST JCT 1 9933 728.00 .80
*SUB07-POST JCT 25 106168 R 723.00 27.09
*SUB07-PRE JCT 1 39063 726.00 7.07
*SUB07-PRE JCT 2 50114 725.00 10.04
*SUB07-PRE JCT 10 80555 725.00 18.71
*SUB07-PRE JCT 100 130117 724.00 33.21
*SUB07-PRE JCT 1 9221 730.00 .80
*SUB07-PRE JCT 25 99292 724.00 24.10
SUB07A-POST AREA 1 1229 721.00 .42
SUB07A-POST AREA 2 2090 720.00 .77
SUB07A-POST AREA 10 4955 716.00 2.04
SUB07A-POST AREA 100 10443 716.00 4.49
SUB07A-POST AREA 1 0 1.00 .00
SUB07A-POST AREA 25 6944 716.00 2.94
C
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID
-------------- Type
-- Event cu.ft Trun min

SUB07A-PRE - ----
AREA ------
1 ---------- --
2884 ---------
731.00
SUB07A-PRE AREA 2 4906 731.00
SUB07A-PRE AREA 10 11632 728.00
SUB07A-PRE AREA 100 24519 728.00
SUB07A-PRE AREA 1 0 1.00
SUB07A-PRE AREA 25 16302 728.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
.48
1.00
2.83
6.38
.00
4.13
SUB07B-POST AREA 1 1474 734.00 .29
SUB07B-POST AREA 2 2096 734.00 .42
SUB07B-POST AREA 10 3887 734.00 .80
SUB07B-POST AREA 100 6892 734.00 1.43
SUB07B-POST AREA 1 83 740.00 .00
SUB07B-POST AREA 25 5016 734.00 1.04
SUB07B-PRE AREA 1 1256 737.00 .24
•
SUB07B-PRE AREA 2 1800 737.00 .36
SUB07B-PRE AREA 10 3383 733.00 .69
SUB07B-PRE AREA 100 6058 733.00 1.25
SUB07B-PRE AREA 1 48 732.00 .00
SUB07B-PRE AREA 25 4386 733.00 .90
SUB07C-POST AREA 1 34946 715.00 14.09
SUB07C-POST AREA 2 43430 715.00 17.28
SUB07C-POST AREA 10 65563 715.00 25.50
SUB07C-POST AREA 100 99563 715.00 37.95
SUB07C-POST AREA 1 9196 715.00 3.95
SUB07C-POST AREA 25 78627 715.00 30.30
SUB07C-PRE AREA 1 34946 715.00 14.09
SUB07C-PRE AREA 2 43430 715.00 17.28
SUB07C-PRE AREA 10 65563 715.00 25.50
SUB07C-PRE AREA 100 99563 715.00 37.95
SUB07C-PRE AREA 1 9196 715.00 3.95
SUB07C-PRE AREA 25 78627 715.00 30.30
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0-
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
------------
--- Type Event cu.ft Trun min cfs ft cu.ft

TO WETLAND --
#1 ----
AREA ------
1 ---------- --
21481 ---------
715.00 -------- -------- ------------
9.20
TO WETLAND #1 AREA 2 27849 715.00 11.82
TO WETLAND #1 AREA 10 44859 715.00 18.62
TO WETLAND #1 AREA 100 71505 715.00 28.90
TO WETLAND #1 AREA 1 3743 716.00 1.56
TO WETLAND #1 AREA 25 55049 715.00 22.59
TO WETLAND #2 AREA 1 18259 715.00 7.87
TO WETLAND #2 AREA 2 24012 715.00 10.29
TO WETLAND #2 AREA 10 39542 715.00 16.63
TO WETLAND #2 AREA 100 64091 715.00 26.27
TO WETLAND #2 AREA 1 2755 716.00 1.09
TO WETLAND #2 AREA 25 48910 715.00 20.35
TO WETLAND #3 AREA 1 23025 716.00 9.94
•
TO WETLAND #3 AREA 2 30951 715.00 13.36
TO WETLAND #3 AREA 10 52722 715.00 22.49
TO WETLAND #3 AREA 100 87679 715.00 36.57
TO WETLAND #3 AREA 1 2748 720.00 1.00
TO WETLAND #3 AREA 25 66009 715.00 27.91
TO WETLAND #4 AREA 1 7202 715.00 3.11
TO WETLAND #4 AREA 2 9610 715.00 4.14
TO WETLAND #4 AREA 10 16185 715.00 6.88
TO WETLAND #4 AREA 100 26684 715.00 11.07
TO WETLAND #4 AREA 1 932 720.00 .35
TO WETLAND #4 AREA 25 20181 715.00 8.49
WETLAND #1 IN POND 1 21481 715.00 9.20
WETLAND #1 IN POND 2 27849 715.00 11.82
WETLAND #1 IN POND 10 44859 715.00 18.62
WETLAND #1 IN POND 100 71505 715.00 28.90
WETLAND #1 IN POND 1 3743 716.00 1.56
WETLAND #1 IN POND 25 55049 715.00 22.59
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----
---- Type
- Event cu.ft Trun
----
WETLAND
#1 -----
OUT --
-
POND ------
1 ----------
8036 --
R
WETLAND #1 OUT POND 2 14078 R
WETLAND #1 OUT POND 10 30666 R
WETLAND #1 OUT POND 100 56941 R
WETLAND #1 OUT POND 1 2627 R
WETLAND #1 OUT POND 25 40685 R
WETLAND #2 IN POND 1 18259
WETLAND #2 IN POND 2 24012
WETLAND #2 IN POND 10 39542
WETLAND #2 IN POND 100 64091
WETLAND #2 IN POND 1 2755
WETLAND #2 IN POND 25 48910
WETLAND #2 OUT POND 1 11946 R
WETLAND #2 OUT POND 2 17529 R
WETLAND #2 OUT POND 10 32763 R
WETLAND #2 OUT POND 100 57066 R
WETLAND #2 OUT POND 1 1964 R
WETLAND #2 OUT POND 25 42012 R
WETLAND #3 IN POND 1 23025
WETLAND #3 IN POND 2 30951
WETLAND #3 IN POND 10 52722
WETLAND #3 IN POND 100 87679
WETLAND #3 IN POND 1 2748
WETLAND #3 IN POND 25 66009
WETLAND #3 OUT POND 1 16870 R
WETLAND #3 OUT POND 2 24589 R
WETLAND #3 OUT POND 10 46052 R
WETLAND #3 OUT POND 100 80736 R
WETLAND #3 OUT POND 1 2144
WETLAND #3 OUT POND 25 59217 R
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
-
---------
1117.00 --------
.12 --------
371.89 --------
---
17237
823.00 .42 372.03 18804
736.00 2.22 372.63 25503
724.00 10.02 373.52 36065
997.00 .03 370.39 2657
725.00 6.78 372.99 29755
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
760.00 .54 348.93 10458
732.00 1.54 349.18 12514
726.00 4.42 350.08 19931
724.00 11.20 351.00 27698
1165.00 .02 347.80 1948
723.00 10.34 350.38 22382
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
734.00 1.44 347.38 11206
725.00 5.10 347.77 13746
722.00 15.00 348.63 19407
719.00 30.41 349.10 22563
1265.00 .02 345.85 1837
719.00 22.97 348.80 20577
•
SIN:
Bentley PondPack (10.00.027.00)
11:47 AM
Bentley Systems, Inc.
10/19/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\'Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
---------
---
----- Type
-- Event cu.ft Trun min cfs ft cu.ft

WETLAND
#4
IN --
POND ------ --
1 --------
7202 -- ---------
715.00 --------
3.11 -------- ------------
WETLAND #4 IN POND 2 9610 715.00 4.14
WETLAND #4 IN POND 10 16185 715.00 6.88
WETLAND #4 IN POND 100 26684 715.00 11.07
WETLAND #4 IN POND 1 932 720.00 .35
WETLAND #4 IN POND 25 20181 715.00 8.49
WETLAND #4 OUT POND 1 2889 R 1010.00 .05 351.67 5557
WETLAND #4 OUT POND 2 5216 R 792.00 .20 351.78 6014
WETLAND #4 OUT POND 10 11657 R 730.00 1.02 352.40 8562
WETLAND #4 OUT POND 100 22053 R 719.00 9.26 352.80 10295
WETLAND #4 OUT POND 1 677 909.00 .01 350.27 644
WETLAND #4 OUT POND 25 15606 R 723.00 4.73 352.67 9728
•
•
SIN:
Bentley Systems, Inc.
Bentley Pon dPack (10. 00.027.00) 11:47 AM 10/19/2010
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0 * 100-4C 7AUAiW ft%MQ6 4
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Town Hall Common
Total
Depth
Return Event in
1 2.8400
2 3.4300
10 4.9600
100 7.3000
WQ Vol 1.0000
25 5.8600
Rainfall
Type
----------------
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
1w iS a? u?MO
it2 b#3?
RNF ID
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
is
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
------ Type
--- ---- Event
------ cu.ft Trun
--------- min cfs ft cu.ft

COMBINE
JCT
1 - --
36397 ---------
725.00 -------- -------- ------------
6.73
COMBINE JCT 2 45503 724.00 9.26
COMBINE JCT 10 69426 723.00 16.19
COMBINE JCT 100 106433 723.00 27.49
COMBINE JCT 1 9257 728.00 .80
COMBINE JCT 25 83620 723.00 20.48
COMBINE PT JCT 1 36178 725.00 6.69
COMBINE PT JCT 2 45208 724.00 9.21
COMBINE PT JCT 10 68923 723.00 16.11
COMBINE PT JCT 100 105598 723.00 27.36
COMBINE PT JCT 1 9221 729.00 .80
COMBINE PT JCT 25 82990 723.00 20.39
C
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 1011512010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
------ cu.ft Trun

*CRAVEN - PRE
JCT
1 ----------
23340
*CRAVEN - PRE JCT 2 31610
*CRAVEN - PRE JCT 10 54470
*CRAVEN - PRE JCT 100 91385
*CRAVEN - PRE JCT 1 2557
*CRAVEN - PRE JCT 25 68481
CRAVEN - PRE AREA 1 23340
CRAVEN - PRE AREA 2 31610
CRAVEN - PRE AREA 10 54470
CRAVEN - PRE AREA 100 91385
CRAVEN - PRE AREA 1 2557
CRAVEN - PRE AREA 25 68481
• *CRAVEN-POST JCT 1 28813 R
*CRAVEN-POST JCT 2 42118 R
*CRAVEN-POST JCT 10 78820 R
*CRAVEN-POST JCT 100 137808 R
*CRAVEN-POST JCT 1 4111
*CRAVEN-POST JCT 25 101235 R
EX POND - PREIN POND 1 34946
EX POND - PREIN POND 2 43430
EX POND - PREIN POND 10 65563
EX POND - PREIN POND 100 99563
EX POND - PREIN POND 1 9196
EX POND - PREIN POND 25 78627
EX POND - PREOUT POND 1 34923
EX POND - PRECUT POND 2 43408
EX POND - PRECUT POND 10 65540
EX POND - PRECUT POND 100 99541
EX POND - PRECUT POND 1 9174
EX POND - PREOUT POND 25 78604
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs
- ft cu.ft

721.00 -------
8.26 -------- ------------
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
740.00 1.85
725.00 6.52
723.00 18.44
720.00 41.36
1148.00 .04
721.00 32.69
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494
E
SIN:
Bentley PondPack (10.00.027.00)
1:53 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
----------------- Type
---- Event
------ cu.ft Trun
---- min cfs ft cu.ft

EX POND-POST IN
POND
1 ------ --
34946 ---------
715.00 --------
14.09 -------- ------------
EX POND-POST IN POND 2 43430 715.00 17.28
EX POND-POST IN POND 10 65563 715.00 25.50
EX POND-POST IN POND 100 99563 715.00 37.95
EX POND-POST IN POND 1 9196 715.00 3.95
EX POND-POST IN POND 25 78627 715.00 30.30
EX POND-POST OUT POND 1 34923 724.00 6.52 366.48 12652
EX POND-POST OUT POND 2 43408 723.00 8.96 366.56 14754
EX POND-POST OUT POND 10 65540 722.00 15.63 366.74 19255
EX POND-POST OUT POND 100 99541 722.00 26.46 366.94 24585
EX POND-POST OUT POND 1 9174 728.00 .80 366.15 4010
EX POND-POST OUT POND 25 78604 722.00 19.75 366.82 21494
• EXPOND OUT-PRE JCT 1 34923 724.00 6.52
EXPOND OUT-PRE JCT 2 43407 723.00 8.96
EXPOND OUT-PRE JCT 10 65540 722.00 15.63
EXPOND OUT-PRE JCT 100 99541 722.00 26.46
EXPOND OUT-PRE JCT 1 9173 728.00 .80
EXPOND OUT-PRE JCT 25 78604 722.00 19.75
EXPONDOUT-POST JCT 1 34923 724.00 6.52
EXPONDOUT-POST JCT 2 43407 723.00 8.96
EXPONDOUT-POST JCT 10 65540 722.00 15.63
EXPONDOUT-POST JCT 100 99541 722.00 26.46
EXPONDOUT-POST JCT 1 9173 728.00 .80
EXPONDOUT-POST JCT 25 78604 722.00 19.75
*SUBO1-POST JCT 1 2998 716.00 1.28
*SUBO1-POST JCT 2 4189 716.00 1.81
*SUBO1-POST JCT 10 7573 715.00 3.27
*SUBO1-POST JCT 100 13175 715.00 5.61
*SUB01-POST JCT 1 221 721.00 .06
*SUBO1-POST JCT 25 9686 715.00 4.16
J
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------------- Type
-- ---- Event
------ cu.ft
---- Trun min cfs ft cu.ft

SUB01-POST
AREA
1 ------
2998 -- ---------
716.00 -------- -------- ------------
1..28
SUBO1-POST AREA 2 4189 716.00 1.81
SUBO1-POST AREA 10 7573 715.00 3.27
SUBO1-POST AREA 100 13175 715.00 5.61
SUB01-POST AREA 1 221 721.00 .06
SUBO1-POST AREA 25 9686 715.00 4.16
SUBO1-PRE AREA 1 4887 730.00 1.20
SUBO1-PRE AREA 2 7006 730.00 1.76
SUBO1-PRE AREA 10 13160 729.00 3.37
SUBO1-PRE AREA 100 23562 727.00 6.04
SUB01-PRE AREA 1 242 737.00 .01
SUBO1-PRE AREA 25 17060 729.00 4.38
• *SUBO1-PRF JCT 1 4887 730.00 1.20
*SUBO1-PRE JCT 2 7006 730.00 1.76
*SUBO1-PRE JCT 10 13160 729.00 3.37
*SUBO1-PRE JCT 100 23562 727.00 6.04
*SUB01-PRE JCT 1 242 737.00 .01
*SUBO1-PRE JCT 25 17060 729.00 4.38
SUB02-BYPASS AREA 1 626 716.00 .26
SUB02-BYPASS AREA 2 906 716.00 .39
SUB02-BYPASS AREA 10 1725 715.00 .74
SUB02-BYPASS AREA 100 3120 715.00 1.34
SUB02-BYPASS AREA 1 4 723.00 .00
SUB02-BYPASS AREA 25 2247 715.00 .97
*SUB02-POST JCT 1 8672 R 716.00 .31
*SUB02-POST JCT 2 14994 R 716.00 .44
*SUB02-POST JCT 10 32402 R 722.00 2.43
*SUB02-POST JCT 100 60072 R 721.00 10.91
*SUB02-POST JCT 1 2624 R 905.00 .02
*SUB02-POST JCT 25 42943 R 725.00 7.11
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
--- cu.ft Trun

*SUB02-PRE
JCT ---
1 ---------- --
5772
*SUB02-PRE JCT 2 8351
*SUB02-PRE JCT 10 15897
*SUB02-PRE JCT 100 28747
*SUB02-PRE JCT 1 243
*SUB02-PRE JCT 25 20706
SUB02-PRE
SUB02-PRE
SUB02-PRE
SUB02-PRE
SUB02-PRE
SUB02-PRE
is SUB03-POST
SUB03-POST
SUB03-POST
SUB03-POST
SUB03-POST
SUB03-POST
*SUB03-POST
*SUB03-POST
*SUB03-POST
*SUB03-POST
*SUB03-POST
*SUB03-POST
SUB03-PRE
SUB03-PRE
SUB03-PRE
SUB03-PRE
SUB03-PRE
SUB03-PRE
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft

748.00 -------- -------- ------------
.85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
748.00 .85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
716.00 1,96
715.00 2 68
115.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
716.00 1.96
715.00 2.68
715.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
748.00 1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
JCT
JCT
JCT
JCT
JCT
JCT
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
5772
8351
15897
28747
243
20706
4548
6207
10821
18317
455
13662
4548
6207
10821
18317
455
13662
7225
10359
19457
34838
358
25225
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
-------------- Type
--- ---- Event
------ cu.ft Trun min cfs ft cu.ft

*SUB03-PRE
JCT
1 ---------- --
7225 ---------
748.00 -------- -------- ------------
1.04
*SUB03-PRE JCT 2 10359 748.00 1.55
*SUB03-PRE JCT 10 19457 748.00 3.01
*SUB03-PRE JCT 100 34838 748.00 5.41
*SUB03-PRE JCT 1 358 765.00 .01
*SUB03-PRE JCT 25 25225 748.00 3.92
SUB04-POST AREA 1 821 716.00 .35
SUB04-POST AREA 2 1147 715.00 .49
SUB04-POST AREA 10 2074 715.00 .90
SUB04-POST AREA 100 3609 715.00 1.54
SUB04-POST AREA 1 43 720.00 .01
SUB04-POST AREA 25 2653 715.00 1.14
• *SUB04-POST JCT 1 821 716.00 .35
*SUB04?POST JCT 2 1147 715.00 .49
*SUB04-POST JCT 10 2074 715.00 .90
*SUB04-POST JCT 100 3609 715.00 1.54
*SUB04-POST JCT 1 43 720.00 .01
*SUB04-POST JCT 25 2653 715.00 1.14
SUB04-PRE AREA 1 2931 749.00 .42
SUB04-PRE AREA 2 4202 749.00 .63
SUB04-PRE AREA 10 7895 743.00 1.22
SUB04-PRE AREA 100 14136 743.00 2.20
SUB04-PRE AREA 1 144 751.00 .00
SUB04-PRE AREA 25 10235 743.00 1.59
*SUB04-PRE JCT 1 2931 749.00 .42
*SUB04-PRE JCT 2 4202 749.00 .63
*SUB04-PRE JCT 10 7895 743.00 1.22
*SUB04-PRE JCT 100 14136 743.00 2.20
*SUB04-PRE JCT 1 144 751.00 .00
*SUB04-PRE JCT 25 10235 743.00 1.59
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
------ cu.ft Trun

*SUB05-PRE
JCT
1 ---------- --
5648
*SUB05-PRE JCT 2 8139
*SUB05-PRE JCT 10 15401
*SUB05-PRE JCT 100 27729
*SUB05-PRE JCT 1 255
*SUB05-PRE JCT 25 20019
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
--
-

749.00 -
---- -------- ------------
.74
747.00 1.10
747.00 2.18
747.00 3.96
762.00 .01
747.00 2.85
756.00 .36
756.00 .55
756.00 1.09
756.00 2.00
788.00 .00
756.00 1.43
742.00 .41
742.00 .61
742.00 1.19
742.00 2.14
749.00 .00
742.00 1.55
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
SUB05A-PRE AREA 1
SUB05A-PRE AREA 2
SUB05A-PRE AREA 10
SUB05A-PRE AREA 100
SUB05A-PRE AREA 1
SUB05A-PRE AREA 25
• SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
JCT
JCT
JCT
JCT
JCT
JCT
l
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
•
3066
4437
8447
15276
128
11002
2582
3702
6955
12453
127
9017
2016
3002
5960
11117
44
7878
2016
3002
5960
11117
44
7878
SIN:
Bentley PondPack (10.00.027.00)
1:53 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
------ cu.ft Trun

SUB06-PRE
AREA
1 ----------
11447 --
SUB06-PRE AREA 2 16560
SUB06-PRE AREA 10 31522
SUB06-PRE AREA 100 57002
SUB06-PRE AREA 1 483
SUB06-PRE AREA 25 41059
*SUB06-PRE JCT 1 11447
*SUB06-PRE JCT 2 16560
*SUB06-PRE JCT 10 31522
*SUB06-PRE JCT 100 57002
*SUB06-PRE JCT 1 483
*SUB06-PRE JCT 25 41059
• *SUB07-POST JCT 1 40513 R
*SUB07-POST JCT 2 52807 R
*SUB07-POST JCT 10 86036 R
*SUB07-POST JCT 100 138929 R
*SUB07-POST JCT 1 9933
*SUB07-POST JCT 25 106168 R
*SUB07-PRE JCT 1 39063
*SUB07-PRE JCT 2 50114
*SUB07-PRE JCT 10 80555
*SUB07-PRE JCT 100 130117
*SUB07-PRE JCT 1 9221
*SUB07-PRE JCT 25 99292
SUB07A-POST AREA 1 1229
SUB07A-POST AREA 2 2090
SUB07A-POST AREA 10 4955
SUB07A-POST AREA 100 10443
SUB07A-POST AREA 1 0
SUB07A-POST AREA 25 6944
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
-

747.00 -------- -------- ---------
--
1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
724.00 6,GR
723.00 9.72
723.00 18.50
721.00 39.73
728.00 .80
723.00 27.09
726.00 7.07
725.00 10.04
725.00 18.71
724.00 33.21
730.00 .80
724.00 24.10
721.00 .42
720.00 .77
716.00 2.04
716.00 4.49
1.00 .00
716.00 2.94
•
S/N:
Bentley PondPack (10.00.027.00)
1:53 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
--- cu.ft Trun

SUB07A-PRE
AREA ---
1 ---------- --
2884
SUB07A-PRE AREA 2 4906
SUB07A-PRE AREA 10 11632
SUB07A-PRE AREA 100 24519
SUB07A-PRE AREA 1 0
SUB07A-PRE AREA 25 16302
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
SU$Q7B-PRF
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft

731.00 -------- -------- ------------
.48
731.00 1.00
728.00 2.83
728.00 6.38
1.00 .00
728.00 4.13
734.00 .29
734.00 .42
734.00 .80
734.00 1.43
740.00 .00
734.00 1.04
737.00 .24
737.00 .36
733.00 .69
733.00 1.25
732.00 .00
733.00 .90
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
is
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
1474
2096
3887
6892
83
5016
1256
1800
3383
6058
48
4386
34946
43430
65563
99563
9196
78627
34946
43430
65563
99563
9196
78627
S/N:
Bentley PondPack (10.00.027.00)
1:53 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
0
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
-----------
------ Type
---- Event
------ cu.ft Trun
--- min cfs ft cu.ft

TO WETLAND
#1
AREA
1 ------- --
21481 ---------
715.00 -------- -------- ------------
9.20
TO WETLAND #1 AREA 2 27849 715.00 11.82
TO WETLAND #1 AREA 10 44859 715.00 18.62
TO WETLAND #1 AREA 100 71505 715.00 28.90
TO WETLAND #1 AREA 1 3743 716.00 1.56
TO WETLAND #1 AREA 25 55049 715.00 22.59
TO WETLAND #2 AREA 1 18259 715.00 7.87
TO WETLAND #2 AREA 2 24012 715.00 10.29
TO WETLAND #2 AREA 10 39542 715.00 16.63
TO WETLAND #2 AREA 100 64091 715.00 26.27
TO WETLAND #2 AREA 1 2755 716.00 1.09
TO WETLAND #2 AREA 25 48910 715.00 20.35
TO WETLAND #3 AREA 1 23025 71.6.00 9.94
•
TO WETLAND #3 AREA 2 30951 715.00 13.36
TO WETLAND #3 AREA 10 52722 '715.00 22.49
TO WETLAND #3 AREA 100 87679 715.00 36.57
TO WETLAND #3 AREA 1 2748 720.00 1.00
TO WETLAND #3 AREA 25 66009 715.00 27.91
TO WETLAND #4 AREA 1 7202 715.00 3.11
TO WETLAND #4 AREA 2 9610 715.00 4.14
TO WETLAND #4 AREA 10 16185 715.00 6.88
TO WETLAND #4 AREA 100 26684 715.00 11.07
TO WETLAND #4 AREA 1 932 720.00 .35
TO WETLAND #4 AREA 25 20181 715.00 8.49
WETLAND #1 IN POND 1 21481 715.00 9.20
WETLAND #1 IN POND 2 27849 715.00 11.82
WETLAND #1 IN POND 10 44859 715.00 18.62
WETLAND #1 IN POND 100 71505 715.00 28.90
WETLAND #1 IN POND 1 3743 716.00 1.56
WETLAND #1 IN POND 25 55049 715.00 22.59
C
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
----
----- Type
---- Event
------ cu.ft
- Trun min cfs ft cu.ft

WETLAND
#1
OUT
POND
1 ---------
8047 --
R ---------
1139.00 --------
.12 --------
371.89 ------------
17235
WETLAND #1 OUT POND 2 14089 R 825.00 .42 372.03 18803
WETLAND #1 OUT POND 10 30678 R 736.00 2.22 372.63 25503
WETLAND #1 OUT POND 100 56953 R 724.00 10.06 373.52 36042
WETLAND #1 OUT POND 1 2621 R 1031.00 .03 370.39 2661
WETLAND #1 OUT POND 25 40697 R 725.00 6.79 372.99 29753
WETLAND #2 IN POND 1 18259 715.00 7.87
WETLAND #2 IN POND 2 24012 715.00 10.29
WETLAND #2 IN POND 10 39542 715.00 16.63
WETLAND #2 IN POND 100 64091 715.00 26.27
WETLAND #2 IN POND 1 2755 716.00 1.09
WETLAND #2 IN POND 25 48910 715.00 20.35
WETLAND #2 OUT POND 1 11946 R 760.00 .54 348.93 10458
•
WETLAND #2 OUT POND 2 17529 R 732.00 1.54 349.18 12514
WETLAND #2 OUT POND 10 32763 R 726.00 4.42 350.08 19931
WETLAND #2 OUT POND 100 57066 R 724.00 11.20 351.00 27698
WETLAND #2 OUT POND 1 1964 R 1165.00 .02 347.80 1948
WETLAND #2 OUT POND 25 42012 R 723.00 10.34 350.38 22382
WETLAND #3 IN POND 1 23025 716.00 9.94
WETLAND #3 IN POND 2 30951 715.00 13.36
WETLAND #3 IN POND 10 52722 715.00 22.49
WETLAND #3 IN POND 100 87679 715.00 36.57
WETLAND #3 IN POND 1 2748 720.00 1.00
WETLAND #3 IN POND 25 66009 715.00 27.91
WETLAND #3 OUT POND 1 16869 R 734.00 1.44 347.38 11205
WETLAND #3 OUT POND 2 24592 R 725.00 5.10 347.77 13745
WETLAND #3 OUT POND 10 46058 R 722.00 15.00 348.63 19406
WETLAND #3 OUT POND 100 80743 R 719.00 30.41 349.10 22563
WETLAND #3 OUT POND 1 2147 866.00 .02 345.85 1838
WETLAND #3 OUT POND 25 59224 R 719.00 22.97 348.80 20577
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
---------
---
----- Type
---- Event
------ cu.ft Trun min cfs ft cu.ft

WETLAND
#4
IN
POND
1 ----------
7202 -- ---------
715.00 --------
3.11 -------- ------------
WETLAND #4 IN POND 2 9610 715.00 4.14
WETLAND #4 IN POND 10 16185 715.00 6.88
WETLAND #4 IN POND 100 26684 715.00 11.07
WETLAND #4 IN POND 1 932 720.00 .35
WETLAND #4 IN POND 25 20181 715.00 8.49
WETLAND #4 OUT POND 1 2889 R 1010.00 .05 351.67 5557
WETLAND #4 OUT POND 2 5216 R 792.00 .20 351.78 6014
WETLAND #4 OUT POND 10 11657 R 730.00 1.02 352.40 8562
WETLAND #4 OUT POND 100 22053 R 719.00 9.26 352.80 10295
WETLAND #4 OUT POND 1 677 909.00 .01 350.27 644
WETLAND #4 OUT POND 25 15606 R 723.00 4.73 352.67 9728
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:53 PM 10/15/2010
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Project3\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
* 7045?0p%?Fw 7#Vr1LV"*9 p6j"t44 4
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Town Hall Common
6TW is or.+ wERM
*2, 4w 3)
Total
Depth Rainfal l
Return Event
---------
- in Type RN F ID
--
-
-
1 ------
2.8400 ----------
Synthetic ------
Curve -------
TypeII --------
24hr
2 3.4300 Synthetic Curve TypeII 24hr
10 4.9600 Synthetic Curve TypeII 24hr
100 7.3000 Synthetic Curve TypeII 24hr
WQ Vol 1.0000 Synthetic Curve TypeII 24hr
25 5.8600 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
•
Return HYG Vol Qpeak
Node ID
------------- Type
---- ---- Event
------ cu.ft Trun
-- min

COMBINE
JCT
1 -------- --
36397 ---------
725.00
COMBINE JCT 2 45503 724.00
COMBINE JCT 10 69426 723.00
COMBINE JCT 100 106433 723.00
COMBINE JCT 1 9257 728.00
COMBINE JCT 25 83620 723.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
6.73
9.26
16.19
27.49
.80
20.48
COMBINE PT JCT 1 36178 725.00 6.69
COMBINE PT JCT 2 45208 724.00 9.21
COMBINE PT JCT 10 68923 723.00 16.11
COMBINE PT JCT 100 105598 723.00 27.36
COMBINE PT JCT 1 9221 729.00 .80
COMBINE PT JCT 25 82990 723.00 20.39
•
S/N:
Bentley PondPack (10.00.027.00)
1:55 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID
---
------- Type
- ---- Event
------ cu.ft Trun
---------- -- min
---------
------
*CRAVEN - PRE JCT 1 23340 721.00
*CRAVEN - PRE JCT 2 31610 721.00
*CRAVEN - PRE JCT 10 54470 721.00
*CRAVEN - PRE JCT 100 91385 721.00
*CRAVEN - PRE JCT 1 2557 724.00
*CRAVEN - PRE JCT 25 68481 721.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
8.26
11.19
19.06
31.27
.70
23.75
CRAVEN - PRE AREA 1 23340 721.00 8.26
CRAVEN - PRE AREA 2 31610 721.00 11.19
CRAVEN - PRE AREA 10 54470 721.00 19.06
CRAVEN - PRE AREA 100 91385 721.00 31.27
CRAVEN - PRE AREA 1 2557 724.00 .70
CRAVEN - PRE AREA 25 68481 721.00 23.75
• *CRAVEN-POST JCT 1 28825 R 740.00 1.85
*CRAVEN-POST JCT 2 42131 R 725.00 6.52
*CRAVEN-POST JCT 10 78830 R 723.00 18.44
*CRAVEN-POST JCT 100 137817 R 722.00 37.74
*CRAVEN-POST JCT 1 4137 1027.00 .04
*CRAVEN-POST JCT 25 101245 R 720.00 30.99
EX POND - PREIN POND 1 34946 715.00 14.09
EX POND - PREIN POND 2 43430 715.00 17.28
EX POND - PREIN POND 10 65563 715.00 25.50
EX POND - PREIN POND 100 99563 715.00 37.95
EX POND - PREIN POND 1 9196 715.00 3.95
EX POND - PREIN POND 25 78627 715.00 30.30
EX POND - PREOUT POND 1 34923 724.00 6.52 366.48 12652
EX POND - PREOUT POND 2 43408 723.00 8.96 366.56 14754
EX POND - PREOUT POND 10 65540 722.00 15.63 366.74 19255
EX POND - PREOUT POND 100 99541 722.00 26.46 366.94 24585
EX POND - PREOUT POND 1 9174 728.00 .80 366.15 4010
EX POND - PREOUT POND 25 78604 722.00 19.75 366.82 21494
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
is
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
----------------- Type
---- Event
------ cu.ft Trun
---------- -- min
--------- cfs
-------- ft cu.ft
-------- ------------
EX POND-POST IN POND 1 34946 715.00 14.09
EX POND-POST IN POND 2 43430 715.00 17.28
EX POND-POST IN POND 10 65563 715.00 25.50
EX POND-POST IN POND 100 99563 715.00 37.95
EX POND-POST IN POND 1 9196 715.00 3.95
EX POND-POST IN POND 25 78627 715.00 30.30
EX POND-POST OUT POND 1 34923 724.00 6.52 366.48 12652
EX POND-POST OUT POND 2 43408 723.00 8.96 366.56 14754
EX POND-POST OUT POND 10 65540 722.00 15.63 366.74 19255
EX POND-POST OUT POND 100 99541 722.00 26.46 366.94 24585
EX POND-POST OUT POND 1 9174 728.00 .80 366.15 4010
EX POND-POST OUT POND 25 78604 722.00 19.75 366.82 21494
EXPOND OUT-PRE JCT 1 34923 724.00 6.52
EXPOND OUT-PRE JCT 2 43407 723.00 8.96
EXPOND OUT-PRE JCT 10 65540 722.00 15.63
EXPOND OUT-PRE JCT 100 99541 722.00 26.46
EXPOND OUT-PRE JCT 1 9173 728.00 .80
EXPOND OUT-PRE JCT 25 78604 722.00 19.75
EXPONDOUT-POST JCT 1 34923 724.00 6.52
EXPONDOUT-POST JCT 2 43407 723.00 8.96
EXPONDOUT-POST JCT 10 65540 722.00 15.63
EXPONDOUT-POST JCT 100 99541 722.00 26.46
EXPONDOUT-POST JCT 1 9173 728.00 .80
EXPONDOUT-POST JCT 25 78604 722.00 19.75
*SUB01-POST JCT 1 2998 716.00 1.28
*SUB01-POST JCT 2 4189 716.00 1.81
*SUB01-POST JCT 10 7573 715.00 3.27
*SUB01-POST JCT 100 13175 715.00 5.61
*SUB01-POST JCT 1 221 721.00 .06
*SUB01-POST JCT 25 9686 715.00 4.16
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event cu.ft Trun min cfs ft cu.ft
-------- -------- ------------
----------------
SUB01-POST - ----
AREA ------
1 ----------
2998 -- ---------
716.00 1.28
SUBO1-POST AREA 2 4189 716.00 1.81
SUBO1-POST AREA 10 7573 715.00 3.27
SUBO1-POST AREA 100 13175 715.00 5.61
SUB01-POST AREA 1 221 721.00 .06
SUBO1-POST AREA 25 9686 715.00 4.16
SUBO1-PRE AREA 1 4887 730.00 1.20
SUBO1-PRE AREA 2 7006 730.00 1.76
SUBO1-PRE AREA 10 13160 729.00 3.37
SUBO1-PRE AREA 100 23562 727.00 6.04
SUB01-PRE AREA 1 242 737.00 .01
SUBO1-PRE AREA 25 17060 729.00 4.38
• *SUBO1-PRE JCT 1 4887 730.00 1.20
*SUBO1-PRE JCT 2 7006 730.00 1.76
*SUBO1-PRE JCT 10 13160 '729.00 3.37
*SUBO1-PRE JCT 100 23562 727.00 6.04
*SUB01-PRE JCT 1 242 737.00 .01
*SUBO1-PRE JCT 25 17060 729.00 4.38
SUB02-BYPASS AREA 1 626 716.00 .26
SUB02-BYPASS AREA 2 906 716.00 .39
SUB02-BYPASS AREA 10 1725 715.00 .74
SUB02-BYPASS AREA 100 3120 715.00 1.34
SUB02-BYPASS AREA 1 4 723.00 .00
SUB02-BYPASS AREA 25 2247 715.00 .97
*SUB02-POST JCT 1 8672 R 716.00 .31
*SUB02-POST JCT 2 14994 R 716.00 .44
*SUB02-POST JCT 10 32402 R 722.00 2.43
*SUB02-POST JCT 100 60072 R 721.00 10.91
*SUB02-POST JCT 1 2624 R 905.00 .02
*SUB02-POST JCT 25 42943 R 725.00 7.11
•
SIN:
Bentley PondPack (10.00.027.00)
1:55 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
•
E
Return HYG Vol Qpeak
Node ID
---------- Type
--- ---- Event
------ cu.ft Trun
---------- -- min
---------
----
*SUB02-PRE JCT 1 5772 748.00
*SUB02-PRE JCT 2 8351 748.00
*SUB02-PRE JCT 10 15897 747.00
*SUB02-PRE JCT 100 28747 741.00
*SUB02-PRE JCT 1 243 766.00
*SUB02-PRE JCT 25 20706 741.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
.85
1.28
2.52
4.61
.01
3.30
SUB02-PRE AREA 1 5772 748.00 .85
SUB02-PRE AREA 2 8351 748.00 1.28
SUB02-PRE AREA 10 15897 747.00 2.52
SUB02-PRE AREA 100 28747 741.00 4.61
SUB02-PRE AREA 1 243 766.00 .01
SUB02-PRE AREA 25 20706 741.00 3.30
SUB03-POST AREA 1 4548 716.00 1.96
SUB03-POST AREA 2 6207 715.00 2.68
SUB03-POST AREA 10 10821 715.00 4.64
SUB03-POST AREA 100 18317 715.00 7.71
SUB03-POST AREA 1 455 721.00 .16
SUB03-POST AREA 25 13662 715.00 5.82
*SUB03-POST JCT 1 4548 716.00 1.96
*SUB03-POST JCT 2 6207 715.00 2.68
*SUB03-POST JCT 10 10821 715.00 4.64
*SUB03-POST JCT 100 18317 715.00 7.71
*SUB03-POST JCT 1 455 721.00 .16
*SUB03-POST JCT 25 13662 715.00 5.82
SUB03-PRE AREA 1 7225 748.00 1.04
SUB03-PRE AREA 2 10359 748.00 1.55
SUB03-PRE AREA 10 19457 748.00 3.01
SUB03-PRE AREA 100 34838 748.00 5.41
SUB03-PRE AREA 1 358 765.00 .01
SUB03-PRE AREA 25 25225 748.00 3.92
SIN:
Bentley PondPack (10.00.027.00) 1:55 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event
-
-- cu.ft Trun
---------- -- min
--------- cfs ft cu.ft
-------- -------- ------------
---------------
*SUB03-PRE -- ----
JCT -
--
1 7225 748.00 1.04
*SUB03-PRE JCT 2 10359 748.00 1.55
*SUB03-PRE JCT 10 19457 748.00 3.01
*SUB03-PRE JCT 100 34838 748.00 5.41
*SUB03-PRE JCT 1 358 765.00 .01
*SUB03-PRE JCT 25 25225 748.00 3.92
SUB04-POST AREA 1 821 716.00 .35
SUB04-POST AREA 2 1147 715.00 .49
SUB04-POST AREA 10 2074 715.00 .90
SUB04-POST AREA 100 3609 715.00 1.54
SUB04-POST AREA 1 43 720.00 .01
SUB04-POST AREA 25 2653 715.00 1.14
• *SUB04-POST JCT 1. 821 716.00 .35
*SUB04-POST JCT 2 1147 715.00 .49
*SUB04-POST JCT 10 2074 715.00 .90
*SUB04-POST JCT 100 3609 715.00 1.54
*SUB04-POST JCT 1 43 720.00 .01
*SUB04-POST JCT 25 2653 715.00 1.14
SUB04-PRE AREA 1 2931 749.00 .42
SUB04-PRE AREA 2 4202 749.00 .63
SUB04-PRE AREA 10 7895 743.00 1.22
SUB04-PRE AREA 100 14136 743.00 2.20
SUB04-PRE AREA 1 144 751.00 .00
SUB04-PRE AREA 25 10235 743.00 1.59
*SUB04-PRE JCT 1 2931 749.00 .42
*SUB04-PRE JCT 2 4202 749.00 .63
*SUB04-PRE JCT 10 7895 743.00 1.22
*SUB04-PRE JCT 100 14136 743.00 2.20
*SUB04-PRE JCT 1 144 751.00 .00
*SUB04-PRE JCT 25 10235 743.00 1.59

SIN:
Bentley PondPack (10.00.027.00)
1:55 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event cu.ft Trun min
--------- cfs
-------- ft cu.ft
-------- ------------
---------------
*SUB05-PRE -- ----
JCT ------
1 ----------
5648 --
749.00 .74
*SUB05-PRE JCT 2 8139 747.00 1.10
*SUB05-PRE JCT 10 15401 747.00 2.18
*SUB05-PRE JCT 100 27729 747.00 3.96
*SUB05-PRE JCT 1, 255 762.00 .01
*SUB05-PRE JCT 25 20019 747.00 2.85
SUB05A-PRE AREA 1 3066 756.00 .36
SUB05A-PRE AREA 2 4437 756.00 .55
SUB05A-PRE AREA 10 8447 756.00 1.09
SUB05A-PRE AREA 100 15276 756.00 2.00
SUB05A-PRE AREA 1 128 788.00 .00
SUB05A-PRE AREA 25 11002 756.00 1.43
• SUB05B-PRE AREA 1 2582 742.00 .41
SUB05B-PRE AREA 2 3702 742.00 .61
SUB05B-PRE AREA 10 6955 742.00 1.19
SUB05B-PRE AREA 100 12453 742.00 2.14
SUB05B-PRE AREA 1 127 749.00 .00
SUB05B-PRE AREA 25 9017 742.00 1.55
SUB06-POST AREA 1 2016 716.00 .81
SUB06-POST AREA 2 3002 716.00 1.26
SUB06-POST AREA 10 5960 716.00 2.57
SUB06-POST AREA 100 11117 715.00 4.80
SUB06-POST AREA 1 44 801.00 .00
SUB06-POST AREA 25 7878 715.00 3.40
*SUB06-POST JCT 1 2016 716.00 .81
*SUB06-POST JCT 2 3002 716.00 1.26
*SUB06-POST JCT 10 5960 716.00 2.57
*SUB06-POST JCT 100 11117 715.00 4.80
*SUB06-POST JCT 1 44 801.00 .00
*SUB06-POST JCT 25 7878 715.00 3.40
•
SIN: Bentley Systems, Inc.
Bentley Pond Pack (10 .00.027.00) 1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type
-- ---- Event
------ cu.ft
---------- Trun
--
---------------
SUB06-PRE AREA 1 11447
SUB06-PRE AREA 2 16560
SUB06-PRE AREA 10 31522
SUB06-PRE AREA 100 57002
SUB06-PRE AREA 1 483
SUB06-PRE AREA 25 41059
*SUB06-PRE JCT 1 11447
*SUB06-PRE JCT 2 16560
*SUB06-PRE JCT 10 31522
*SUB06-PRE JCT 100 57002
*SUB06-PRE JCT 1 483
*SUB06-PRE JCT 25 41059
• *SUB07-.POST JCT 1 40513 R
*SUB07-POST JCT 2 52807 R
*SUB07-POST JCT 10 86036 R
*SUB07-POST JCT 100 138929 R
*SUB07-POST JCT 1 9933
*SUB07-POST JCT 25 106168 R
*SUB07-PRE JCT 1 39063
*SUB07-PRE JCT 2 50114
*SUB07-PRE JCT 10 80555
*SUB07-PRE JCT 100 130117
*SUB07-PRE JCT 1 9221
*SUB07-PRE JCT 25 99292
SUB07A-POST AREA 1 1229
SUB07A-POST AREA 2 2090
SUB07A-POST AREA 10 4955
SUB07A-POST AREA 100 10443
SUB07A-POST AREA 1 0
SUB07A-POST AREA 25 6944
Max
Qpeak Qpeak Max WSEL Pond Storage
min
----- cfs ft cu.ft
-------- -------- ------------
----
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
724.00 6.98
723.00 9.72
723.00 18.50
721.00 39.73
728.00 .80
723.00 27.09
726.00 7.07
725.00 10.04
725.00 18.71
724.00 33.21
730.00 .80
724.00 24.10
721.00 .42
720.00 .77
716.00 2.04
716.00 4.49
1.00 .00
716.00 2.94
•
SIN:
Bentley PondPack (10.00.027.00)
Bentley Systems, Inc.
1:55 PM 10/15/2010
•
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
------ cu.ft Trun
---------- --
SUB07A-PRE AREA 1 2884
SUB07A-PRE AREA 2 4906
SUB07A-PRE AREA 10 11632
SUB07A-PRE AREA 100 24519
SUB07A-PRE AREA 1 0
SUB07A-PRE AREA 25 16302
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
SUB07B-POST
• SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
•
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
SIN:
Bentley PondPack (10.00.027.00)
1474
2096
3887
6892
83
5016
1256
1800
3383
6058
48
4386
34946
43430
65563
99563
9196
78627
34946
43430
65563
99563
9196
78627
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
-------- -------- ------------
731.00 .48
731.00 1.00
728.00 2.83
728.00 6.38
1.00 .00
728.00 4.13
734.00 .29
734.00 .42
734.00 .80
734.00 1.43
740.00 .00
734.00 1.04
'737.00 .24
737.00 .36
'/33.00 .69
733.00 1.25
732.00 .00
733.00 .90
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
Bentley Systems, Inc.
1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
u
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
------------
----- Type
---- Event
------ cu.ft Trun
---------- min cfs ft cu.ft

TO WETLAND
#1
AREA
1 --
21481 ---------
715.00 -------- -------- ------------
9.20
TO WETLAND #1 AREA 2 27849 715.00 11.82
TO WETLAND #1 AREA 10 44859 715.00 18.62
TO WETLAND #1 AREA 100 71505 715.00 28.90
TO WETLAND #1 AREA 1 3743 716.00 1.56
TO WETLAND #1 AREA 25 55049 715.00 22.59
TO WETLAND #2 AREA 1 18259 715.00 7.87
TO WETLAND #2 AREA 2 24012 715.00 10.29
TO WETLAND #2 AREA 10 39542 715.00 16.63
TO WETLAND #2 AREA 100 64091 715.00 26.27
TO WETLAND #2 AREA 1 2755 716.00 1.09
TO WETLAND #2 AREA 25 48910 715.00 20.35
• TO WETLAND #3 AREA 1 23025 716.00 9.94
TO WETLAND #3 AREA 2 30951 715.00 13.36
TO WETLAND #3 AREA 10 52722 715.00 22.49
TO WETLAND #3 AREA 100 87679 715.00 36.57
TO WETLAND #3 AREA 1 2748 720.00 1.00
TO WETLAND #3 AREA 25 66009 715.00 27.91
TO WETLAND #4 AREA 1 7202 715.00 3.11
TO WETLAND #4 AREA 2 9610 715.00 4.14
TO WETLAND #4 AREA 10 16185 715.00 6.88
TO WETLAND #4 AREA 100 26684 715.00 11.07
TO WETLAND #4 AREA 1 932 720.00 .35
TO WETLAND #4 AREA 25 20181 715.00 8.49
WETLAND #1 IN POND 1 21481 715.00 9.20
WETLAND #1 IN POND 2 27849 715.00 11.82
WETLAND #1 IN POND 10 44859 715.00 18.62
WETLAND #1 IN POND 100 71505 715.00 28.90
WETLAND #1 IN POND 1 3743 716.00 1.56
WETLAND #1 IN POND 25 55049 715.00 22.59
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
----
----- Type
---- Event
------ cu.ft
-- Trun min cfs ft cu.ft

WETLAND
#1
OUT
POND
1 --------
8047 --
R ---------
1139.00 --------
.12 --------
371.89 ------------
17235
WETLAND #1 OUT POND 2 14089 R 825.00 .42 372.03 18803
WETLAND #1 OUT POND 10 30678 R 736.00 2.22 372.63 25503
WETLAND #1 OUT POND 100 56953 R 724.00 10.06 373.52 36042
WETLAND #1 OUT POND 1 2621 R 1031.00 .03 370.39 2661
WETLAND #1 OUT POND 25 40697 R 725.00 6.79 372.99 29753
WETLAND #2 IN POND 1 18259 715.00 7.87
WETLAND #2 IN POND 2 24012 715.00 10.29
WETLAND #2 IN POND 10 39542 715.00 16.63
WETLAND #2 IN POND 100 64091 715.00 26.27
WETLAND #2 IN POND 1 2755 716.00 1.09
WETLAND #2 IN POND 25 48910 715.00 20.35
• WETLAND #2 OUT POND 1 11958 R 760.00 .54 348.93 10458
WETLAND #2 OUT POND 2 17541 ',,:R 732.00 1.54 349.18 12514
WETLAND #2 OUT POND 10 32774 R 726.00 4.42 350.08 19931
WETLAND #2 OUT POND 100 57075 R 724.00 9.08 351.16 29063
WETLAND #2 OUT POND 1 1990 R 939.00 .02 347.80 1918
WETLAND #2 OUT POND 25 42022 R 724.00 8.25 350.44 22929
WETLAND #3 IN POND 1 23025 716.00 9.94
WETLAND #3 IN POND 2 30951 715.00 13.36
WETLAND #3 IN POND 10 52722 715.00 22.49
WETLAND #3 IN POND 100 87679 715.00 36.57
WETLAND #3 IN POND 1 2748 720.00 1.00
WETLAND #3 IN POND 25 66009 715.00 27.91
WETLAND #3 OUT POND 1 16869 R 734.00 1.44 347.38 11205
WETLAND #3 OUT POND 2 24592 R 725.00 5.10 347.77 13746
WETLAND #3 OUT POND 10 46058 R 722.00 15.01 348.63 19407
WETLAND #3 OUT POND 100 80743 R 720.00 28.80 349.17 23021
WETLAND #3 OUT POND 1 2147 866.00 .02 345.85 1838
WETLAND #3 OUT POND 25 59223 R 720.00 22.95 348.80 20579
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:55 PM 10/15/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
-----
---- Type
---- Event
------ cu.ft
- Trun min cfs ft cu.ft

WETLAND
#4
IN
POND
1 -
--------
7202 -- ---------
715.00 --------
3.11 -------- ------------
WETLAND #4 IN POND 2 9610 715.00 4.14
WETLAND #4 IN POND 10 16185 715.00 6.88
WETLAND #4 IN POND 100 26684 715.00 11.07
WETLAND #4 IN POND 1 932 720.00 .35
WETLAND #4 IN POND 25 20181 715.00 8.49
WETLAND #4 OUT POND 1 2889 R 1010.00 .05 351.67 5557
WETLAND #4 OUT POND 2 5216 R 792.00 .20 351.78 6014
WETLAND #4 OUT POND 10 11657 R 730.00 1.02 352.40 8562
WETLAND #4 OUT POND 100 22053 R 719.00 9.26 352.80 10295
WETLAND #4 OUT POND 1 677 909.00 .01 350.27 644
WETLAND #4 OUT POND 25 15606 R 723.00 4.73 352.67 9728
•
•
S/N:
Bentley PondPack (10.00.027.00)
1:55 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
loowpvc V""Offet vab
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Town Hall Common
Total
Depth
Return Event in
1 2.8400
2 3.4300
10 4.9600
100 7.3000
WQ Vol 1.0000
25 5.8600
Rainfall
Type
----------------
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
7 w K oN u4?
#21# 3 E
S(e*&s W,NoT
RNF ID
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
•

Return HYG Vol Qpeak Qpeak Max WSEL
Node ID
--------
------ Type
--- ---- Event
------ cu.ft Trun min cfs ft

COMBINE
JCT
1 ---------- --
36397 ---------
725.00 -------- --------
6.73
COMBINE JCT 2 45503 724.00 9.26
COMBINE JCT 10 69426 723.00 16.19
COMBINE JCT 100 106433 723.00 27.49
COMBINE JCT 1 9257 728.00 .80
COMBINE JCT 25 83620 723.00 20.48
COMBINE PT JCT 1 36178 725.00 6.69
COMBINE PT JCT 2 45208 724.00 9.21
COMBINE PT JCT 10 68923 723.00 16.11
COMBINE PT JCT 100 105598 723.00 27.36
COMBINE PT JCT 1 9221 729.00 .80
COMBINE PT JCT 25 82990 723.00 20.39
E
Max
Pond Storage
cu.ft
------------
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
- Type
---- Event
------ cu.ft
---------- Trun
----------------
*CRAVEN - PRE JCT 1 23340
*CRAVEN - PRE JCT 2 31610
*CRAVEN - PRE JCT 10 54470
*CRAVEN - PRE JCT 100 91385
*CRAVEN - PRE JCT 1 2557
*CRAVEN - PRE JCT 25 68481
CRAVEN - PRE AREA 1 23340
CRAVEN - PRE AREA 2 31610
CRAVEN - PRE AREA 10 54470
CRAVEN - PRE AREA 100 91385
CRAVEN - PRE AREA 1 2557
CRAVEN - PRE AREA 25 68481
• *CRAVEN-POST Jr,T 1 28655 R
*CRAVEN-POST JCT 2 41973 R
*CRAVEN-POST JCT 10 78696 R
*CRAVEN-POST JCT 100 137702 R
*CRAVEN-POST JCT 1 3409
*CRAVEN-POST JCT 25 101119 R
EX POND - PREIN POND 1 34946
EX POND - PREIN POND 2 43430
EX POND - PREIN POND 10 65563
EX POND - PREIN POND 100 99563
EX POND - PREIN POND 1 9196
EX POND - PREIN POND 25 78627
EX POND - PREOUT POND 1 34923
EX POND - PREOUT POND 2 43408
EX POND - PREOUT POND 10 65540
EX POND - PREOUT POND 100 99541
EX POND - PREOUT POND 1 9174
EX POND - PREOUT POND 25 78604
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--- cfs
-------- ft
-------- cu.ft
------------
------
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
741.00 1.87
725.00 6.56
723.00 18.63
722.00 36.08
1059.00 .04
720.00 30.18
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494
•
SIN:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
----------------- Type
---- Event
------ cu.ft Trun
---------- -- min
--------- cfs
-------- ft cu.ft
-------- ------------
EX POND-POST IN POND 1 34946 715.00 14.09
EX POND-POST IN POND 2 43430 715.00 17.28
EX POND-POST IN POND 10 65563 715.00 25.50
EX POND-POST IN POND 100 99563 715.00 37.95
EX POND-POST IN POND 1 9196 715.00 3.95
EX POND-POST IN POND 25 78627 715.00 30.30
EX POND-POST OUT POND 1 34923 724.00 6.52 366.48 12652
EX POND-POST OUT POND 2 43408 723.00 8.96 366.56 14754
EX POND-POST OUT POND 10 65540 722.00 15.63 366.74 19255
EX POND-POST OUT POND 100 99541 722.00 26.46 366.94 24585
EX POND-POST OUT POND 1 9174 728.00 .80 366.15 4010
EX POND-POST OUT POND 25 78604 722.00 19.75 366.82 21494
• EXPOND OUT-PRE JCT 1 34923 724.00 6.52
EXPOND OUT-PRE JCT 2 43407 723.00 8.96
EXPOND OUT-PRE JCT 10 65540 722.00 15.63
EXPOND OUT-PRE JCT 100 99541 722.00 26.46
EXPOND OUT-PRE JCT 1 9173 728.00 .80
EXPOND OUT-PRE JCT 25 78604 722.00 19.75
EXPONDOUT-POST JCT 1 34923 724.00 6.52
EXPONDOUT-POST JCT 2 43407 723.00 8.96
EXPONDOUT-POST JCT 10 65540 722.00 15.63
EXPONDOUT-POST JCT 100 99541 722.00 26.46
EXPONDOUT-POST JCT 1 9173 728.00 .80
EXPONDOUT-POST JCT 25 78604 722.00 19.75
*SUB01-POST JCT 1 2998 716.00 1.28
*SUB01-POST JCT 2 4189 716.00 1.81
*SUB01-POST JCT 10 7573 715.00 3.27
*SUB01-POST JCT 100 13175 715.00 5.61
*SUB01-POST JCT 1 221 721.00 .06
*SUB01-POST JCT 25 9686 715.00 4.16
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
is
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event cu.ft Trun
- min
--------- cfs ft cu.ft
-------- -------- ------------
----------------
SUB01-POST - ----
AREA ------
1 ----------
2998 - 716.00 1.28
SUBO1-POST AREA 2 4189 716.00 1.81
SUBO1-POST AREA 10 7573 715.00 3.27
SUBO1-POST AREA 100 13175 715.00 5.61
SUB01-POST AREA 1 221 721.00 .06
SUB01-POST AREA 25 9686 715.00 4.16
SUBO1-PRE AREA 1 4887 730.00 1.20
SUBO1-PRE AREA 2 7006 730.00 1.76
SUBO1-PRE AREA 10 13160 729.00 3.37
SUBO1-PRE AREA 100 23562 727.00 6.04
SUB01-PRE AREA 1 242 737.00 .01
SUBO1-PRE AREA 25 17060 729.00 4.38
• *SUBO1-PRE JCT 1 4887 730.00 1.20
*SUBO1-PRE JCT 2 7006 730.00 1.76
*SUBO1-PRE JCT 10 13160 729.00 3.37
*SUBO1-PRE JCT 100 23562 727.00 6.04
*SUB01-PRE JCT 1 242 737.00 .01
*SUBO1-PRE JCT 25 17060 729.00 4.38
SUB02-BYPASS AREA 1 626 716.00 .26
SUB02-BYPASS AREA 2 906 716.00 .39
SUB02-BYPASS AREA 10 1725 715.00 .74
SUB02-BYPASS AREA 100 3120 715.00 1.34
SUB02-BYPASS AREA 1 4 723.00 .00
SUB02-BYPASS AREA 25 2247 715.00 .97
*SUB02-POST JCT 1 8672 R 716.00 .31
*SUB02-POST JCT 2 14994 R 716.00 .44
*SUB02-POST JCT 10 32402 R 722.00 2.43
*SUB02-POST JCT 100 60072 R 721.00 10.91
*SUB02-POST JCT 1 2624 R 905.00 .02
*SUB02-POST JCT 25 42943 R 725.00 7.11
•
rj
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------------- Type
-- ---- Event
------ cu.ft Trun
---------- -- min
--------- cfs ft cu.ft
-------- -------- ------------
*SUB02-PRE JCT 1 5772 748.00 .85
*SUB02-PRE JCT 2 8351 748.00 1.28
*SUB02-PRE JCT 10 15897 747.00 2.52
*SUB02-PRE JCT 100 28747 741.00 4.61
*SUB02-PRE JCT 1 243 766.00 .01
*SUB02-PRE JCT 25 20706 741.00 3.30
SUB02-PRE AREA 1 5772 748.00 .85
SUB02-PRE AREA 2 8351 748.00 1.28
SUB02-PRE AREA 10 15897 747.00 2.52
SUB02-PRE AREA 100 28747 741.00 4.61
SUB02-PRE AREA 1 243 766.00 .01
SUB02-PRE AREA 25 20706 741.00 3.30
• SUB03-POST AREA 1 4548 716.00 1.96
SUB03-POST AREA 2 6207 715.00 2.68
SUB03-POST AREA 10 10821 715.00 4.64
SUB03-POST AREA 100 18317 715.00 7.71
SUB03-POST AREA 1 455 721.00 .16
SUB03-POST AREA 25 13662 715.00 5.82
*SUB03-POST JCT 1 4548 716.00 1.96
*SUB03-POST JCT 2 6207 715.00 2.68
*SUB03-POST JCT 10 10821 715.00 4.64
*SUB03-POST JCT 100 18317 715.00 7.71
*SUB03-POST JCT 1 455 721.00 .16
*SUB03-POST JCT 25 13662 715.00 5.82
SUB03-PRE AREA 1 7225 748.00 1.04
SUB03-PRE AREA 2 10359 748.00 1.55
SUB03-PRE AREA 10 19457 748.00 3.01
SUB03-PRE AREA 100 34838 748.00 5.41
SUB03-PRE AREA 1 358 765.00 .01
SUB03-PRE AREA 25 25225 748.00 3.92
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
is
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
------- Type
-- ---- Event
------ cu.ft Trun
---------- --
--------
*SUB03-PRE JCT 1 7225
*SUB03-PRE JCT 2 10359
*SUB03-PRE JCT 10 19457
*SUB03-PRE JCT 100 34838
*SUB03-PRE JCT 1 358
*SUB03-PRE JCT 25 25225
SUB04-POST AREA 1 821
SUB04-POST AREA 2 1147
SUB04-POST AREA 10 2074
SUB04-POST AREA 100 3609
SUB04-POST AREA 1 43
SUB04-POST AREA 25 2653
• *SUB04-POST JCT 1 821
*SUB04-POST JCT 2 1147
*SUB04-POST JCT 10 2074
*SUB04-POST JCT 100 3609
*SUB04-POST JCT 1 43
*SUB04-POST JCT 25 2653
SUB04-PRE AREA 1 2931
SUB04-PRE AREA 2 4202
SUB04-PRE AREA 10 7895
SUB04-PRE AREA 100 14136
SUB04-PRE AREA 1 144
SUB04-PRE AREA 25 10235
*SUB04-PRE JCT 1 2931
*SUB04-PRE JCT 2 4202
*SUB04-PRE JCT 10 7895
*SUB04-PRE JCT 100 14136
*SUB04-PRE JCT 1 144
*SUB04-PRE JCT 25 10235
Qpeak
min
748.00
748.00
748.00
748.00
765.00
748.00
716.00
715.00
715.00
715.00
720.00
715.00
716.00
715.00
715.00
715.00
720.00
715.00
749.00
749.00
743.00
743.00
751.00
743.00
749.00
749.00
743.00
743.00
751.00
743.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
1.04
1.55
3.01
5.41
.01
3.92
.35
.49
.90
1.54
.01
1.14
.35
.49
.90
1.54
.01
1.14
.42
.63
1.22
2.20
.00
1.59
.42
.63
1.22
2.20
.00
1.59
•
S/N:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
is
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
------ cu.ft Trun

*SUB05-PRE
JCT
1 ---------- --
5648
*SUB05-PRE JCT 2 8139
*SUB05-PRE JCT 10 15401
*SUB05-PRE JCT 100 27729
*SUB05-PRE JCT 1 255
*SUB05-PRE JCT 25 20019
SUB05A-PRE AREA 1
SUB05A-PRE AREA 2
SUB05A-PRE AREA 10
SUB05A-PRE AREA 100
SUB05A-PRE AREA 1
SUB05A-PRE AREA 25
• SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
SUB05B-PRE
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST
*SUB06-POST

AREA
AREA
AREA
AREA
AREA
AREA
JCT
JCT
JCT
JCT
JCT
JCT
1
2
10
100
1
25
1
2
10
100
1
25
3066
4437
8447
15276
128
11002
2582
3702
6955
12453
127
9017
2016
3002
5960
11117
44
7878
2016
3002
5960
11117
44
7878
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
-------- -------- ------------
749.00 .74
747.00 1.10
747.00 2.18
747.00 3.96
762.00 .01
747.00 2.85
756.00 .36
756.00 .55
756.00 1.09
756.00 2.00
788.00 .00
756.00 1.43
742.00 .41
742.00 .61
742.00 1.19
742.00 2.14
749.00 .00
742.00 1.55
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
SIN:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
--- cu.ft Trun

SUB06-PRE
AREA ---
1 ----------
11447 --
SUB06-PRE AREA 2 16560
SUB06-PRE AREA 10 31522
SUB06-PRE AREA 100 57002
SUB06-PRE AREA 1 483
SUB06-PRE AREA 25 41059
*SUB06-PRE JCT 1 11447
*SUB06-PRE JCT 2 16560
*SUB06-PRE JCT 10 31522
*SUB06-PRE JCT 100 57002
*SUB06-PRE JCT 1 483
*SUB06-PRE JCT 25 41059
• *SUB07-POST JCT 1 40513 R
*SUB07-POST JCT 2 52807 R
*SUB07-POST. JCT 10 86036 R
*SUB07-POST JCT 100 138929 R
*SUB07-POST JCT 1 9933
*SUB07-POST JCT 25 106168 R
*SUB07-PRE JCT 1 39063
*SUB07-PRE JCT 2 50114
*SUB07-PRE JCT 10 80555
*SUB07-PRE JCT 100 130117
*SUB07-PRE JCT 1 9221
*SUB07-PRE JCT 25 99292
SUB07A-POST AREA 1 1229
SUB07A-POST AREA 2 2090
SUB07A-POST AREA 10 4955
SUB07A-POST AREA 100 10443
SUB07A-POST AREA 1 0
SUB07A-POST AREA 25 6944
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
-------
-

747.00 - --
----- ------------
1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
724.00 6.98
723.00 9.72
723.00 18.50
721.00 39.73
728.00 .80
723.00 27.09
726.00 7.07
725.00 10.04
725.00 18.71
724.00 33.21
730.00 .80
724.00 24.10
721.00 .42
720.00 .77
716.00 2.04
716.00 4.49
1.00 .00
716.00 2.94
•
S/N:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
is
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
------ cu.ft Trun
-----

SUB07A-PRE
AREA
1 ----- --
2884
SUB07A-PRE AREA 2 4906
SUB07A-PRE AREA 10 11632
SUB07A-PRE AREA 100 24519
SUB07A-PRE AREA 1 0
SUB07A-PRE AREA 25 16302
Qpeak
min
731.00
731.00
728.00
728.00
1.00
728.00
SUB07B-POST AREA 1
SUB07B-POST AREA 2
SUB07B-POST AREA 10
SUB07B-POST AREA 100
SUB07B-POST AREA 1
SUB07B-POST AREA 25
• SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07B-PRE
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-POST
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
SUB07C-PRE
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
AREA
1
2
10
100
1
25
1
2
10
100
1
25
1
2
10
100
1
25
•
1474
2096
3887
6892
83
5016
1256
1800
3383
6058
48
4386
34946
43430
65563
99563
9196
78627
34946
43430
65563
99563
9196
78627
734.00
734.00
734.00
734.00
740.00
734.00
737.00
737.00
733.00
733.00
732.00
733.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
.48
1.00
2.83
6.38
.00
4.13
.29
.42
.80
1.43
.00
1.04
.24
.36
.69
1.25
.00
.90
14.09
17.28
25.50
37.95
3.95
30.30
14.09
17.28
25.50
37.95
3.95
30.30
SIN:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-----------
------ Type
---- Event
----- cu.ft Trun

TO WETLAND
#1
AREA -
1 ----------
21481
TO WETLAND #1 AREA 2 27849
TO WETLAND #1 AREA 10 44859
TO WETLAND #1 AREA 100 71505
TO WETLAND #1 AREA 1 3743
TO WETLAND #1 AREA 25 55049
TO WETLAND #2 AREA 1 18259
TO WETLAND #2 AREA 2 24012
TO WETLAND #2 AREA 10 39542
TO WETLAND #2 AREA 100 64091
TO WETLAND #2 AREA 1 2755
TO WETLAND #2 AREA 25 48910
• TO WETLAND #3 AREA 1 23025
TO WETLAND #3 AREA 2 30951
TO WETLAND #3 AREA 10 52722
TO WETLAND #3 AREA 100 87679
TO WETLAND #3 AREA 1 2748
TO WETLAND #3 AREA 25 66009
TO WETLAND #4 AREA 1 7202
TO WETLAND #4 AREA 2 9610
TO WETLAND #4 AREA 10 16185
TO WETLAND #4 AREA 100 26684
TO WETLAND #4 AREA 1 932
TO WETLAND #4 AREA 25 20181
WETLAND #1 IN POND 1 21481
WETLAND #1 IN POND 2 27849
WETLAND #1 IN POND 10 44859
WETLAND #1 IN POND 100 71505
WETLAND #1 IN POND 1 3743
WETLAND #1 IN POND 25 55049
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--------- cfs ft cu.ft
-------- ----
- ------------
715.00 ---
9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
715.00 3.11
715.00 4.14
715.00 6.88
715.00 11.07
720.00 .35
715.00 8.49
715.00 9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
•
S/N:
Bentley PondPack (10.00.027.00)
2:04 PM
Bentley Systems, Inc.
10/15/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
----
----- Type
---- Event
------ cu.ft Trun min cfs ft cu.ft

WETLAND
#1
OUT
POND
1 ----------
8047 --
R ---------
1139.00 --------
.12 --------
371.89 ------------
17235
WETLAND #1 OUT POND 2 14089 R 825.00 .42 372.03 18803
WETLAND #1 OUT POND 10 30678 R 736.00 2.22 372.63 25503
WETLAND #1 OUT POND 100 56953 R 724.00 10.06 373.52 36042
WETLAND #1 OUT POND 1 2621 R 1031.00 .03 370.39 2661
WETLAND #1 OUT POND 25 40697 R 725.00 6.79 372.99 29753
WETLAND #2 IN POND 1 18259 715.00 7.87
WETLAND #2 IN POND 2 24012 715.00 10.29
WETLAND #2 IN POND 10 39542 715.00 16.63
WETLAND #2 IN POND 100 64091 715.00 26.27
WETLAND #2 IN POND 1 2755 716.00 1.09
WETLAND #2 IN POND 25 48910 715.00 20.35
• WETLAND #2 OUT POND 1 11786 R 758.00 348.93 10493
WETLAND #2 OUT POND 2 17382 R 730.00 1.57 349.19 12586
WETLAND #2 OUT POND 10 32638 R 726.00 4.55 350.09 20005
WETLAND #2 OUT POND 100 56959 R 725.00 8.42 351.22 29637
WETLAND #2 OUT POND 1 1263 1371.00 .02 347.84 2230
WETLAND #2 OUT POND 25 41896 R 724.00 7.48 350.48 23280
WETLAND #3 IN POND 1 23025 716.00 9.94
WETLAND #3 IN POND 2 30951 715.00 13.36
WETLAND #3 IN POND 10 52722 715.00 22.49
WETLAND #3 IN POND 100 87679 715.00 36.57
WETLAND #3 IN POND 1 2748 720.00 1.00
WETLAND #3 IN POND 25 66009 715.00 27.91
WETLAND #3 OUT POND 1 16869 R 734.00 1.44 347.38 11211
WETLAND #3 OUT POND 2 24592 R 725.00 5.10 347.77 13747
WETLAND #3 OUT POND 10 46058 R 722.00 15.01 348.63 19407
WETLAND #3 OUT POND 100 80743 R 721.00 27.80 349.23 23431
WETLAND #3 OUT POND 1 2147 866.00 .02 345.85 1838
WETLAND #3 OUT POND 25 59224 R 720.00 22.92 348.80 20582
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
----
----- Type
---- Event
------ cu.ft
-------- Trun min cfs ft cu.ft

WETLAND
#4
IN
POND
1 --
7202 -- ---------
715.00 --------
3.11 -------- ------------
WETLAND #4 IN POND 2 9610 715.00 4.14
WETLAND #4 IN POND 10 16185 715.00 6.88
WETLAND #4 IN POND 100 26684 715.00 11.07
WETLAND #4 IN POND 1 932 720.00 .35
WETLAND #4 IN POND 25 20181 715.00 8.49
WETLAND #4 OUT POND 1 2889 R 1010.00 .05 351.67 5557
WETLAND #4 OUT POND 2 5216 R 792.00 .20 351.78 6014
WETLAND #4 OUT POND 10 11657 R 730.00 1.02 352.40 8562
WETLAND #4 OUT POND 100 22053 R 719.00 9.26 352.80 10295
WETLAND #4 OUT POND 1 677 909.00 .01 350.27 644
WETLAND #4 OUT POND 25 15606 R 723.00 4.73 352.67 9728
is
is
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 2:04 PM 10/15/2010
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
• V10&%VZVHUQ"fMX aQuica
MASTER DESIGN STORM SUMMARY CIsoo
Network Storm Collection: Town Hall Common
?? 110ko CL"W)
Total
Depth Rainfal l
Return Event
------------ in
- Type RNF ID

1 -----
2.8400 ----------
Synthetic ------
Curve ------
TypeII ----------
24hr
2 3.4300 Synthetic Curve TypeII 24hr
10 4.9600 Synthetic Curve TypeII 24hr
100 7.3000 Synthetic Curve TypeII 24hr
WQ Vol 1.0000 Synthetic Curve TypeII 24hr
25 5.8600 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
•
Return HYG Vol Qpeak
Node ID
------------- Type
---- ---- Event
----- cu.ft Trun min

COMBINE
JCT -
1 ---------- --
36397 ---------
725.00
COMBINE JCT 2 45503 724.00
COMBINE JCT 10 69426 723.00
COMBINE JCT 100 106433 723.00
COMBINE JCT 1 9257 728.00
COMBINE JCT 25 83620 723.00
Max
Qpeak Max WSEL Pond Storage
cfs ft cu.ft
-------- -------- ------------
6.73
9.26
16.19
27.49
.80
20.48
COMBINE PT JCT 1 36178 725.00 6.69
COMBINE PT JCT 2 45208 724.00 9.21
COMBINE PT JCT 10 68923 723.00 16.11
COMBINE PT JCT 100 105598 723.00 27.36
COMBINE PT JCT 1 9221 729.00 .80
COMBINE PT JCT 25 82990 723.00 20.39
•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.02
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
C7
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
--
- cu.ft Trun

*CRAVEN - PRE
JCT -
--
1 ----------
23340
*CRAVEN - PRE JCT 2 31610
*CRAVEN - PRE JCT 10 54470
*CRAVEN - PRE JCT 100 91385
*CRAVEN - PRE JCT 1 2557
*CRAVEN - PRE JCT 25 68481
CRAVEN - PRE AREA 1 23340
CRAVEN - PRE AREA 2 31610
CRAVEN - PRE AREA 10 54470
CRAVEN - PRE AREA 100 91385
CRAVEN - PRE AREA 1 2557
CRAVEN - PRE AREA 25 68481
• *CRAVEN-POST JCT 1 41231
kCRAVEN-POST JCT 2 54910
*CRAVEN-POST JCT 10 92210
*CRAVEN-POST JCT 100 151718
*CRAVEN-POST JCT 1 5450
*CRAVEN-POST JCT 25 114865
EX POND - PREIN POND 1 34946
EX POND - PREIN POND 2 43430
EX POND - PREIN POND 10 65563
EX POND - PREIN POND 100 99563
EX POND - PREIN POND 1 9196
EX POND - PREIN POND 25 78627
EX POND - PRECUT POND 1 34923
EX POND - PREOUT POND 2 43408
EX POND - PRECUT POND 10 65540
EX POND - PRECUT POND 100 99541
EX POND - PRECUT POND 1 9174
EX POND - PRECUT POND 25 78604
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
721.00 --------
8.26 -------- ------------
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
721.00 8.26
721.00 11.19
721.00 19.06
721.00 31.27
724.00 .70
721.00 23.75
723.00 8.76
723.00 11.59
721.00 24.35
722.00 36.13
743.00 .29
720.00 30.76
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494
•
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
---- cu.ft Trun

EX POND-POST IN
POND --
1 ---------- --
34946
EX POND-POST IN POND 2 43430
EX POND-POST IN POND 10 65563
EX POND-POST IN POND 100 99563
EX POND-POST IN POND 1 9196
EX POND-POST IN POND 25 78627
EX POND-POST OUT POND 1 34923
EX POND-POST OUT POND 2 43408
EX POND-POST OUT POND 10 65540
EX POND-POST OUT POND 100 99541
EX POND-POST OUT POND 1 9174
EX POND-POST OUT POND 25 78604
• EXPOND OUT-PRE JCT 1 34923
EXPOND OUT-PRE JCT 2 43407
EXPOND OUT-PRE JCT 10 65540
EXPOND OUT-PRE JCT 100 99541
EXPOND OUT-PRE JCT 1 9173
EXPOND OUT-PRE JCT 25 78604
EXPONDOUT-POST JCT 1 34923
EXPONDOUT-POST JCT 2 43407
EXPONDOUT-POST JCT 10 65540
EXPONDOUT-POST JCT 100 99541
EXPONDOUT-POST JCT 1 9173
EXPONDOUT-POST JCT 25 78604
*SUB01-POST JCT 1 2998
*SUB01-POST JCT 2 4189
*SUB01-POST JCT 10 7573
*SUB01-POST JCT 100 13175
*SUB01-POST JCT 1 221
*SUB01-POST JCT 25 9686
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
715.00 --------
14.09 -------- ------------
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
724.00 6.52 366.48 12652
723.00 8.96 366.56 14754
722.00 15.63 366.74 19255
722.00 26.46 366.94 24585
728.00 .80 366.15 4010
722.00 19.75 366.82 21494
724.00 6.52
723.00 8.96
722.00 15.63
722.00 26.46
728.00 .80
722.00 19.75
724.00 6.52
723.00 8.96
722.00 15.63
722.00 26.46
728.00 .80
722.00 19.75
716.00 1.28
716.00 1.81
715.00 3.27
715.00 5.61
721.00 .06
715.00 4.16
C
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- ---- Event
- cu.ft Trun

SUB01-POST
AREA -----
1 ---------- --
2998
SUB01-POST AREA 2 4189
SUB01-POST AREA 10 7573
SUB01-POST AREA 100 13175
SUB01-POST AREA 1 221
SUB01-POST AREA 25 9686
SUB01-PRE AREA 1 4887
SUB01-PRE AREA 2 7006
SUB01-PRE AREA 10 13160
SUB01-PRE AREA 100 23562
SUB01-PRE AREA 1 242
SUB01-PRE AREA 25 17060
• *SUB01-PRE JCT 1 4887
kSUB01-PRE JCT 2 7006
*SUB01-PRE JCT 10 13160
*SUB01-PRE JCT 100 23562
*SUB01-PRE JCT 1 242
*SUB01-PRE JCT 25 17060
SUB02-BYPASS AREA 1 626
SUB02-BYPASS AREA 2 906
SUB02-BYPASS AREA 10 1725
SUB02-BYPASS AREA 100 3120
SUB02-BYPASS AREA 1 4
SUB02-BYPASS AREA 25 2247
*SUB02-POST JCT 1 22059
*SUB02-POST JCT 2 28705
*SUB02-POST JCT 10 46507
*SUB02-POST JCT 100 74513
*SUB02-POST JCT 1 3699
*SUB02-POST JCT 25 57204
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
716.00 -------- -------- ------------
1.28
716.00 1.81
715.00 3.27
715.00 5.61
721.00 .06
715.00 4.16
730.00 1.20
730.00 1.76
729.00 3.37
727.00 6.04
737.00 .01
729.00 4.38
730.00 1.20
730.00 1.76
729.00 3.37
727.00 6.04
737.00 .01
729.00 4.38
716.00 .26
716.00 .39
715.00 .74
715.00 1.34
723.00 .00
715.00 .97
722.00 2.26
725.00 3.37
722.00 9.89
721.00 11.66
750.00 .16
721.00 10.58
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.05
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event cu.ft Trun

*SUB02-PRE
JCT ------
1 ---------- --
5772
*SUB02-PRE JCT 2 8351
*SUB02-PRE JCT 10 15897
*SUB02-PRE JCT 100 28747
*SUB02-PRE JCT 1 243
*SUB02-PRE JCT 25 20706
SUB02-PRE AREA 1 5772
SUB02-PRE AREA 2 8351
SUB02-PRE AREA 10 15897
SUB02-PRE AREA 100 28747
SUB02-PRE AREA 1 243
SUB02-PRE AREA 25 20706
SUB03-POST AREA 1 4548
•
SUB03-POST AREA 2 6207
SUB03-POST AREA 10 10821
SUB03-POST AREA 100 18317
SUB03-POST AREA 1 455
SUB03-POST AREA 25 13662
*SUB03-POST JCT 1 4548
*SUB03-POST JCT 2 6207
*SUB03-POST JCT 10 10821
*SUB03-POST JCT 100 18317
*SUB03-POST JCT 1 455
*SUB03-POST JCT 25 13662
SUB03-PRE AREA 1 7225
SUB03-PRE AREA 2 10359
SUB03-PRE AREA 10 19457
SUB03-PRE AREA 100 34838
SUB03-PRE AREA 1 358
SUB03-PRE AREA 25 25225
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--- cfs ft cu.ft
------
748.00 -------- -------- ------------
.85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
748.00 .85
748.00 1.28
747.00 2.52
741.00 4.61
766.00 .01
741.00 3.30
716.00 1.96
715.00 2.68
715.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
716.00 1.96
715.00 2.68
715.00 4.64
715.00 7.71
721.00 .16
715.00 5.82
748.00 1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.06
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event cu.ft Trun

*SUB03-PRE
JCT ------
1 ---------- --
7225
*SUB03-PRE JCT 2 10359
*SUB03-PRE JCT 10 19457
*SUB03-PRE JCT 100 34838
*SUB03-PRE JCT 1 358
*SUB03-PRE JCT 25 25225
SUB04-POST AREA 1 821
SUB04-POST AREA 2 1147
SUB04-POST AREA 10 2074
SUB04-POST AREA 100 3609
SUB04-POST AREA 1 43
SUB04-POST AREA 25 2653
• *SUB04-POST JCT 1
*SUB04-POST JCT 2
*SUB04-POST JCT 10
*SUB04-POST JCT 100
*SUB04-POST JCT 1
*SUB04-POST JCT 25
SUB04-PRE AREA 1
SUB04-PRE AREA 2
SUB04-PRE AREA 10
SUB04-PRE AREA 100
SUB04-PRE AREA 1
SUB04-PRE AREA 25
*SUB04-PRE JCT 1
*SUB04-PRE JCT 2
*SUB04-PRE JCT 10
*SUB04-PRE JCT 100
*SUB04-PRE JCT 1
*SUB04-PRE JCT 25
•
821
1147
2074
3609
43
2653
2931
4202
7895
14136
144
10235
2931
4202
7895
14136
144
10235
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
748.00 -------- -------- ------------
1.04
748.00 1.55
748.00 3.01
748.00 5.41
765.00 .01
748.00 3.92
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
716.00 .35
715.00 .49
715.00 .90
715.00 1.54
720.00 .01
715.00 1.14
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
749.00 .42
749.00 .63
743.00 1.22
743.00 2.20
751.00 .00
743.00 1.59
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.07
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-------------- Type
--- ---- Event
- cu.ft Trun

*SUB05-PRE
JCT -----
1 ---------- --
5648
*SUB05-PRE JCT 2 8139
*SUB05-PRE JCT 10 15401
*SUB05-PRE JCT 100 27729
*SUB05-PRE JCT 1 255
*SUB05-PRE JCT 25 20019
SUB05A-PRE AREA 1 3066
SUB05A-PRE AREA 2 4437
SUB05A-PRE AREA 10 8447
SUB05A-PRE AREA 100 15276
SUB05A-PRE AREA 1 128
SUB05A-PRE AREA 25 11002
• SUB05B-PRE AREA 1 2582
SUB05B-PRE AREA 2 3702
SUB05B-PRE AREA 10 6955
SUB05B-PRE AREA 100 12453
SUB05B-PRE AREA 1 127
SUB05B-PRE AREA 25 9017
SUB06-POST AREA 1 2016
SUB06-POST AREA 2 3002
SUB06-POST AREA 10 5960
SUB06-POST AREA 100 11117
SUB06-POST AREA 1 44
SUB06-POST AREA 25 7878
*SUB06-POST JCT 1 2016
*SUB06-POST JCT 2 3002
*SUB06-POST JCT 10 5960
*SUB06-POST JCT 100 11117
*SUB06-POST JCT 1 44
*SUB06-POST JCT 25 7878
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
749.00 -------- -------- ------------
.74
747.00 1.10
747.00 2.18
747.00 3.96
762.00 .01
747.00 2.85
756.00 .36
756.00 .55
756.00 1.09
756.00 2.00
788.00 .00
756.00 1.43
742.00 .41
742.00 .61
742.00 1.19
742.00 2.14
749.00 .00
742.00 1.55
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40
716.00 .81
716.00 1.26
716.00 2.57
715.00 4.80
801.00 .00
715.00 3.40

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.08
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- --- Event cu.ft Trun

SUB06-PRE -
AREA ------
1 ---------- --
11447
SUB06-PRE AREA 2 16560
SUB06-PRE AREA 10 31522
SUB06-PRE AREA 100 57002
SUB06-PRE AREA 1 483
SUB06-PRE AREA 25 41059
*SUB06-PRE JCT 1 11447
*SUB06-PRE JCT 2 16560
*SUB06-PRE JCT 10 31522
*SUB06-PRE JCT 100 57002
*SUB06-PRE JCT 1 483
*SUB06-PRE JCT 25 41059
• *SUB07-POST JCT 1 44806
*SUB07-POST JCT 2 57181
*SUB07-POST JCT 10 90544
*SUB07-POST JCT 100 143539
*SUB07-POST JCT 1 10167
*SUB07-POST JCT 25 110723
*SUB07-PRE JCT 1 39063
*SUB07-PRE JCT 2 50114
*SUB07-PRE JCT 10 80555
*SUB07-PRE JCT 100 130117
*SUB07-PRE JCT 1 9221
*SUB07-PRE JCT 25 99292
SUB07A-POST AREA 1 1229
SUB07A-POST AREA 2 2090
SUB07A-POST AREA 10 4955
SUB07A-POST AREA 100 10443
SUB07A-POST AREA 1 0
SUB07A-POST AREA 25 6944
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft cu.ft
---------
747.00 -------- -------- ------------
1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
747.00 1.62
747.00 2.45
747.00 4.86
747.00 8.88
781.00 .02
747.00 6.37
724.00 7.83
723.00 10.76
722.00 22.88
722.00 39.68
728.00 .83
721.00 29.31
726.00 7.07
725.00 10.04
725.00 18.71
724.00 33.21
730.00 .80
724.00 24.10
721.00 .42
720.00 .77
716.00 2.04
716.00 4.49
1.00 .00
716.00 2.94
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.09
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
--------------- Type
-- -- Event cu.ft Trun
-

SUB07A-PRE --
AREA ------
1 ----------
-
2884
SUB07A-PRE AREA 2 4906
SUB07A-PRE AREA 10 11632
SUB07A-PRE AREA 100 24519
SUB07A-PRE AREA 1 0
SUB07A-PRE AREA 25 16302
SUB07B-POST AREA 1 1474
SUB07B-POST AREA 2 2096
SUB07B-POST AREA 10 3887
SUB07B-POST AREA 100 6892
SUB07B-POST AREA 1 83
SUB07B-POST AREA 25 5016
SUB07B-PRE AREA 1 1256
•
SUB07B-PRE AREA 2 1800
SUB07B-PRE AREA 10 3383
SUB07B-PRE AREA 100 6058
SUB07B-PRE AREA 1 48
SUB07B-PRE AREA 25 4386
SUB07C-POST AREA 1 34946
SUB07C-POST AREA 2 43430
SUB07C-POST AREA 10 65563
SUB07C-POST AREA 100 99563
SUB07C-POST AREA 1 9196
SUB07C-POST AREA 25 78627
SUB07C-PRE AREA 1 34946
SUB07C-PRE AREA 2 43430
SUB07C-PRE AREA 10 65563
SUB07C-PRE AREA 100 99563
SUB07C-PRE AREA 1 9196
SUB07C-PRE AREA 25 78627
Max
Qpeak Qpeak Max WSEL Pond Storage
min
-- cfs ft cu.ft
-------
731.00 -------- -------- ------------
.48
731.00 1.00
728.00 2.83
728.00 6.38
1.00 .00
728.00 4.13
734.00 .29
734.00 .42
734.00 .80
734.00 1.43
740.00 .00
734.00 1.04
737.00 .24
737.00 .36
733.00 .69
733.00 1.25
732.00 .00
733.00 .90
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
715.00 14.09
715.00 17.28
715.00 25.50
715.00 37.95
715.00 3.95
715.00 30.30
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.10
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
0-
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-----------
------ Type
---- Event
-- cu.ft Trun

TO WETLAND
#1
AREA ----
1 ----------
21481
TO WETLAND #1 AREA 2 27849
TO WETLAND #1 AREA 10 44859
TO WETLAND #1 AREA 100 71505
TO WETLAND #1 AREA 1 3743
TO WETLAND #1 AREA 25 55049
TO WETLAND #2 AREA 1 18259
TO WETLAND #2 AREA 2 24012
TO WETLAND #2 AREA 10 39542
TO WETLAND #2 AREA 100 64091
TO WETLAND #2 AREA 1 2755
TO WETLAND #2 AREA 25 48910
TO WETLAND #3 AREA 1 23025
•
TO WETLAND #3 AREA 2 30951
TO WETLAND #3 AREA 10 52722
TO WETLAND #3 AREA 100 87679
TO WETLAND #3 AREA 1 2748
TO WETLAND #3 AREA 25 66009
TO WETLAND #4 AREA 1 7202
TO WETLAND #4 AREA 2 9610
TO WETLAND #4 AREA 10 16185
TO WETLAND #4 AREA 100 26684
TO WETLAND #4 AREA 1 932
TO WETLAND #4 AREA 25 20181
WETLAND #1 IN POND 1 21481
WETLAND #1 IN POND 2 27849
WETLAND #1 IN POND 10 44859
WETLAND #1 IN POND 100 71505
WETLAND #1 IN POND 1 3743
WETLAND #1 IN POND 25 55049
Max
Qpeak Qpeak Max WSEL Pond Storage
min
-- cfs ft cu.ft
-------
715.00 -------- -------- ------------
9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
715.00 3.11
715.00 4.14
715.00 6.88
715.00 11.07
720.00 .35
715.00 8.49
715.00 9.20
715.00 11.82
715.00 18.62
715.00 28.90
716.00 1.56
715.00 22.59
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.11
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
•
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID
-=------
----
----- Type
--- Event cu.ft Trun

WETLAND
#1
OUT -
POND ------
1 ----------
21434
WETLAND #1 OUT POND 2 27800
WETLAND #1 OUT POND 10 44782
WETLAND #1 OUT POND 100 71393
WETLAND #1 OUT POND 1 3696
WETLAND #1 OUT POND 25 54957
WETLAND #2 IN POND 1 18259
WETLAND #2 IN POND 2 24012
WETLAND #2 IN POND 10 39542
WETLAND #2 IN POND 100 64091
WETLAND #2 IN POND 1 2755
WETLAND #2 IN POND 25 48910
WETLAND #2 OUT POND 1 18225
•
WETLAND #2 OUT POND 2 23978
WETLAND #2 OUT POND 10 39508
WETLAND #2 OUT POND 100 64057
WETLAND #2 OUT POND 1 2721
WETLAND #2 OUT POND 25 48875
WETLAND #3 IN POND 1 23025
WETLAND #3 IN POND 2 30951
WETLAND #3 IN POND 10 52722
WETLAND #3 IN POND 100 87679
WETLAND #3 IN POND 1 2748
WETLAND #3 IN POND 25 66009
WETLAND #3 OUT POND 1 23007
WETLAND #3 OUT POND 2 30932
WETLAND #3 OUT POND 10 52703
WETLAND #3 OUT POND 100 87661
WETLAND #3 OUT POND 1 2729
WETLAND #3 OUT POND 25 65990
Max
Qpeak Qpeak Max WSEL Pond Storage
min
--- cfs
- ft cu.ft
------
726.00 ------
-
2.13 --------
372.62 ------------
9118
726.00 3.24 372.85 11746
723.00 9.38 373.20 15927
724.00 10.77 373.91 24532
750.00 .16 371.95 1570
724.00 9.90 373.46 19060
715.00 7.87
715.00 10.29
715.00 16.63
715.00 26.27
716.00 1.09
715.00 20.35
725.00 2.24 349.53 7033
726.00 2.70 349.81 9347
724.00 7.23 350.37 14046
725.00 8.48 351.34 22393
743.00 .12 348.78 1021
724.00 7.71 350.72 17053
716.00 9.94
715.00 13.36
715.00 22.49
715.00 36.57
720.00 1.00
715.00 27.91
723.00 6.55 347.90 5816
722.00 8.94 348.12 7261
721.00 17.28 348.69 11022
721.00 27.79 349.23 14699
742.00 .16 347.12 765
719.00 23.32 348.82 11944
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010
Type.... Master Network Summary Page 2.12
Name.... Watershed
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID
--------
----
----- Type
---- Event
---- cu.ft Trun min cfs ft cu.ft

WETLAND
#4
IN
POND --
1 ---------- --
7202 ---------
715.00 --------
3.11 -------- ------------
WETLAND #4 IN POND 2 9610 715.00 4.14
WETLAND #4 IN POND 10 16185 715.00 6.88
WETLAND #4 IN POND 100 26684 715.00 11.07
WETLAND #4 IN POND 1 932 720.00 .35
WETLAND #4 IN POND 25 20181 715.00 8.49
WETLAND #4 OUT POND 1 7181 725.00 .88 352.25 2664
WETLAND #4 OUT POND 2 9589 725.00 1.07 352.48 3637
WETLAND #4 OUT POND 10 16164 721.00 5.42 352.70 4549
WETLAND #4 OUT POND 100 26663 720.00 8.88 352.91 5497
WETLAND #4 OUT POND 1 911 733.00 .04 351.68 301
WETLAND #4 OUT POND 25 20160 718.00 7.27 352.76 4833
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:50 AM 10/19/2010

FINAL STORMWA TER WETLAND W DESIGN
CALCULATIONS
• -_

TOWN HALL COMMONS
PLT-10000
TOWN HALL COMMONS STORMWATER WETLAND #1
PLT-10000
• Stage-Storage Function
Project Name: Town Hall Commons
Designer: J. Finch, PE
Job Number: PLT-10000
Date: 10/5/2010
•
J. FINCH, PE
10/5/2010
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Volume
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (CF)
370.00 0.0 7,289
371.00 1.0 9,227 8258 8258 8258 1.01
372.00 2.0 10,490 9859 9859 18116 1.97
373.00 3.0 11.837 11164 11164 29280 2.95
374.00 4.0 13,266 12551 12551 41832 3.99
375.00 5.0 14,776 14021 14021 55852 5.10
Storage vs. Stage
60000
y = 8121.5x''84'
50000
Rz = 0.9994
. 40000
LL
V
930000
0
0)20000
10000
0 t --4
0.0 1.0 2.0 Stagj.oeet) 4.0 5.0 6.0
Ks = 8121.5
b = 1.1841
0
TOWN HALL COMMONS STORMWATER WETLAND #1 J. FINCH, PE
PLT-10000 10/5/2010
• _> Stage - Storage Function
Ks = 8121.5
b= 1.1841
•
Zo = 370.00
Elevation
[feet] Storage Elevation
[cf] [acre-feet] [feet] 100-Year
[c1] [acre-feet]
370.00 0 0.000 370.00 - -
370.20 1208 0.028 370.20 - -
370.40 2744 0.063 370.40 - -
370.60 4436 0.102 370.60 - -
370.80 6236 0.143 370.80 - -
371.00 8121 0.186 371.00 - -
371.20 10078 0.231 371.20 - -
371.40 12097 0.278 371.40 - -
371.60 14169 0.325 371.60 - -
371.80 16289 0.374 371.80 0 0.000
372.00 18454 0.424 372.00 2164 0.050
372.20 20659 0.474 372.20 4369 0.100
372.40 22900 0.526 372.40 6611 0.152
372.60 25177 0.578 372.60 8888 0.204
372.80 27486 0.631 372.80 11197 0.257
373.00 29826 0.685 373.00 13537 0.311
373.20 32195 0.739 373.20 15905 0.365
373.40 34591 0.794 373.40 18301 0.420
373.60 37013 0.850 373.60 20724 0.476
373.80- ' 39460 0.906 373.80 23171 0.532
374.00 41931 0.963 374.00 25642 0.589
374.20 44425 1.020 374.20 28135 0.646
374.40 46941 1.078 374.40 30651 0.704
374.60 49478 1.136 374.60 33188 0.762
374.80 52035 1.195 374.80 35745 0.821
375.00 54612 1.254 375.00 38322 0.880
E
Type.... Vol: Elev-Volume
Name.... WETLAND #1
Page 3.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
USER DEFINED VOLUME RATING TABLE
Elevation Volume
(ft) (cu.ft)
is
C7
370.00 0
370.20 1208
370.40 2744
370.60 4436
370.80 6236
371.00 8121
371.20 10078
371.40 12097
371.60 14169
371.80 16289
372.00 18454
372.20 20659
372.40 22900
372.60 25177
372.80 27486
373.00 29826
373.20 32195
373.40 34591
373.60 37013
373.80 39460
374.00 41931
374.20 44425
374.40 46941
374.60 49478
374.80 52035
375.00 54612
S/N: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Outlet Input Data
Name.... Wetland#1
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
REQUESTED POND WS ELEVATIONS:
Min.'Elev.= 370.00 ft
Increment = .10 ft
Max. Elev.= 375.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure
----------------- No.
---- Outfall
---- E1, ft E2, ft

Orifice-Circular
01 ---
---> BA ---------
371.800 ---------
375.000
Inlet Box RI ---> BA 372.800 375.000
Orifice-Circular SI ---> BA 370.000 375.000
Culvert-Circular BA ---> TW 370.000 375
000
TW SETUP, DS Channel .
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:43 AM 10/19/2010
Type.... Outlet Input Data
Name.... Wetland#1
Page 2.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = 01
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 3
Invert Elev. = 371.80 ft
Diameter = .5000 ft
Orifice Coeff. _ .600
•
Structure ID = RI
Structure Type
---------------- = Inlet Box
--
# of Openings ------------------
= 1
Invert Elev. = 372.80 ft
Orifice Area = 16.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 16.00 ft
Weir Coeff. = 3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Structure ID = SI
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 370.00 ft
Diameter = .1146 ft
Orifice Coeff. _ .600

SIN: Bentley Systems, Inc.
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Type.... Outlet Input Data
Name.... Wetland#1
Page 2.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = BA
Structure Type
---------------- = Culvert-Circular
--
No. Barrels ------------
= 1 ------
Barrel Diameter = 1.2500 ft
Upstream Invert = 370.00 ft
Dnstream Invert = 369.80 ft
Horiz. Length = 39.00 ft
Barrel Length = 39.00 ft
Barrel Slope = .00513 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000 (forward entrance loss)
Kb = .023225 (per ft of full flow)
Kr = .5000 (reverse entrance loss)
HW Convergence = .001 +/- ft
• INLET CONTROL DATA...
Equation form 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) _ .000
T2 ratio (HW/D) = 1.304
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 370.00 ft ---> Flow = 4.80 cfs
At T2 Elev = 371.63 ft ---> Flow = 5.49 cfs
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:43 AM 10/19/2010
Type.... Outlet Input Data
Name.... Wetland#1
Page 2.04
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments :
OUTLET STRUCTURE INPUT DATA
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:43 AM 10/19/2010
Type.... Composite Rating Curve
Name.... Wetland#1
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****

•
WS Elev, Total Q Notes
-------- -------- ----- --- Converge
----------
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
-------- - Contributi ng Structures

370.00
.00
Free ----
Outfall -----------
(no Q: 01 ---
,RI ------------
,SI,BA)
370.10 .01 Free Outfall SI,BA (no Q: 01,RI)
370.20 .02 Free Outfall SI,BA (no Q: 01,RI)
370.30 .02 Free Outfall SI,BA (no Q: 01,RI)
370.40 .03 Free Outfall SI,BA (no Q: O1,RI)
370.50 .03 Free Outfall SI,BA (no Q: O1,RI)
370.60 .03 Free Outfall SI,BA (no Q: O1,RI)
370.70 .04 Free Outfall SI,BA (no Q: 01,RI)
370.80 .04 Free Outfall SI,BA (no Q: O1,RI)
370.90 .04 Free Outfall SI,BA (no Q: O1,RI)
371.00 .05 Free Outfall SI,BA (no Q: O1,RI)
371.10 .05 Free Outfall SI,BA (no Q: O1,RI)
371.20 .05 Free Outfall SI,BA (no Q: 01,RI)
371.30 .05 Free Outfall SI,BA (no Q: O1,RI)
371.40 .06 Free Outfall SI,BA (no Q: 01,RI)
371.50 .06 Free Outfall SI,BA (no Q: 01,RI)
371.60 .06 Free Outfall SI,BA (no Q: 01,RI)
371.70 .06 Free Outfall SI,BA (no Q: O1,RI)
371.80 .06 Free Outfall SI,BA (no Q: O1,RI)
371.90 .13 Free Outfall 01,SI,BA (no Q: RI)
372.00 .33 Free Outfall 01,SI,BA (no Q: RI)
372.10 .63 Free Outfall O1,SI,BA (no Q: RI)
372.20 1.00 Free Outfall 01,SI,BA (no Q: RI)
372.30 1.48 Free Outfall 01,SI,BA (no Q: RI)
372.40 1.74 Free Outfall 01,SI,BA (no Q: RI)
372.50 1.96 Free Outfall 01,SI,BA (no Q: RI)
372.60 2.17 Free Outfall 01,SI,BA (no Q: RI)
372.70 2.35 Free Outfall 01,SI,BA (no Q: RI)
372.80 2.52 Free Outfall 01,SI,BA (no Q: RI)
372.90 4.19 Free Outfall 01,RI,SI,BA
373.00 6.95 Free Outfall 01,RI,SI,BA
373.10 8.90 Free Outfall 01,RI,SI,BA
373.20 9.37 Free Outfall RI,BA (no Q: Ol,SI)
373.30 9.56 Free Outfall RIBA (no Q: 01,SI)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:43 AM 10/19/2010
Type.... Composite Rating Curve
Name.... Wetland#1
Page 2.22
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
•
•
WS Elev, Total Q Notes
-------- -------- ----- --- Converge
------
----
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
---- Contributing Structures

373.40
9.77 -
Free --- -----
Outfall -------
RIBA ----
(no ---
Q: ------------
O1,SI)
373.50 9.98 Free Outfall RI,BA (no Q: O1,SI)
373.60 10.18 Free Outfall RI,BA (no Q: O1,SI)
373.70 10.37 Free Outfall RIBA (no Q: O1,SI)
373.80 10.56 Free Outfall RIBA (no Q: 01,SI)
373.90 10.75 Free Outfall RIBA (no Q: O1,SI)
374.00 10.93 Free Outfall RIBA (no Q: O1,SI)
374.10 11.11 Free Outfall RI,BA (no Q: O1,SI)
374.20 11.29 Free Outfall RIBA (no Q: O1,SI)
374.30 11.45 Free Outfall RIBA (no Q: O1,SI)
374.40 11.62 Free Outfall RIBA (no Q: O1,SI)
374.50 11.78 Free Outfall RIBA (no Q: O1,SI)
374.60 11.94 Free Outfall RIBA (no Q: O1,SI)
374.70 12.09 Free Outfall RIBA (no Q: O1,SI)
374.80 12.25 Free Outfall RI,BA (no Q: O1,SI)
374.90 12.40 Free Outfall RIBA (no Q: O1,SI)
375.00 12.56 Free Outfall RI,BA (no Q: O1,SI)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:43 AM 10/19/2010
TOWN HALL COMMONS STORMWATER WETLAND #1
PLT-10000 SIZING CALCULATIONS
• _> Determination of Water Quality Volume (WQ V)
WQ v = (P) (R V) (A)112
where,
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total area, A = 3.22 acres
Impervious area = 1.63 acres
Percent impervious cover, I = 50.7 %
Rainfall, P = 1.0 inches
Calculated values:
Rv= 0.51
WQv= 0.14 acre-ft
= 5924 cf.
_> Stormwater Wetland Required Surface Area Calculation
WQ Volume = 5924 cf
Maximum Ponding Depth = 12 inches
Surface Area Required at Normal Pool = 5924 SF
-> Associated Pond Depth in Stormwater Weiland
Ks= 8121.5
b = 1.1841
V = 5924
Normal Pool Elevation = 370 feet
WQ Elevation = 370.77 feet
-> Determination of 1-Yr Pre:-Post Volume Storage Provided by Facility
Input data:
Control Orifice (3 x 6" Dia) Invert = 371.80 feet
Normal Pool Elevation = 370.00 feet
Calculated values:
1-Yr Pre-Dev Runoff Volume (To Wetland #1) = 10,971 cf
1-Yr Post-Dev Runoff Volume (To Wetland #1) = 21,576 cf
1-Yr Pre-Post Volume Difference= 10,606 cf
Ks= 8121.5
• b= 1.1841
Storage Provided @ Orifice Invert 16,289 feet
J. FINCH, PE
10/5/2010
•
TOWN HALL COMMONS
PLT-10000
SIPHON DESIGN
WETLAND #1-1" WQ VOLUME
D orifice = 1.375 inch
# orifices = 1
Ks = 8121.5
b = 1.1841
Cd siphon = 0.60
Normal Pool Elevation = 370.00 feet
Orifice Invert = 369.50 feet
1" WQ Volume = 5924 cf
WSEL @ 1" Runoff Volume = 370.77 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.422 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.010 sf
Q = 0.0323 cfs

Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 2.13 days
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the 1" storm runoff, with a required time of about 2.13 days.
B.R. FINCH, PE
10/4/2010

TOWN HALL COMMONS
PLT-10000
SIPHON DESIGN
WETLAND #1-1 YR PRE-POST VOLUME B.R. FINCH, PE
10/4/2010
D orifice = 1.375 inch
# orifices = 1
Ks = 8121.5
b = 1.1841
Cd siphon = 0.60
Normal Pool Elevation = 370.00 feet
Orifice invert = 369.50 feet
1" Pre-Post Volume = 16289 cf
WSEL @ 1-Yr Pre-Post Volume = 371.80 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.767 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.010 sf
Q = 0.0435 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 4.34 days. I

Conclusion : Use 1- 1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the difference in 1-Yr Pre-Post Runoff Volume, with a required time of about 4.34 days.

•
E
PIPE DESIGN SPECIFICATIONS:
1. ASTM C 764Latest
-- -- Class III, IV, & V
2. AASHTO M-1704Latest
JOINT DESIGN SPECIFICATIONS:
1. ASTM C-443-Latest
2. ASTM C-361-Latest
t
3. Joint Type-R4 with "O" Ring
Rubber Gaskets.
X
s
JI
GS - ° GL TSa
I a
° d °°
4
°
WT...._
°
AS F41 AST TD GD a °
°
»?..?-._.-.vim. n..®? d ,..?.,...,..u«.....a..m?. 04 o
OI I X16"
ID --{ GAP

ID
WT
JT
GD
TD
AS
OI
GW
GS
GL
TS
AST
X
OD Pounds
Per
Foot
Plant
12" B-2114 3 112" 15.260" 14.725" .063" 14.606" .377' 11116" 1" 1" 1/8" 5 314" 19 5/16" 123 VB
15" C-3 31/2" 18.759" 18.224" .063" 18.105" .377" 11/16" 1" 1" 1/8" 51/2" 23 5/16" 191 VB
18" C41/4 31/2" 21.787" 21.252" .063" 21.133" .377" 11116" 1" 1" 118" 6" 26112' 249 VB
24" C- 3 3/4 3 7/8" 29.138" 28.950" .063" 28.408" .400 7/8" 13116" 1" 3/32" 6" 351/2" 367 VB
N.T.S.
Oldcastle Precast
N.C. Products
920 Withers Road Raleigh, NC.27603
Phone: [phone] Fax: [phone]
8'='0" RINGABS
FILE NAME: 450SPC812RTG2_DET.DWG
ISSUE DATE: JULY, 2008
www.oldcastlepmmtcom
Reinforced "O" RING
Modified Bell & Spigot
Copyright @ 2005 owcamu Precast.i..
•

TOWN HALL COMMONS
PLT-10000
Wetland#1
Square Riser/Barrel Anti-Flotation Calculation Sheet
Input Data =>
Inside length of riser = 4.00 feet
Inside width of riser = 4.00 feet
Wall thickness of riser = 6.00 inches
Base thickness of riser = 8.00 inches
Base length of riser = 5.00 feet
Base width of riser = 5.00 feet
Inside height of Riser = 2.80 feet
Concrete unit weight = 142.0 PCF
OD of barrel exiting manhole = 21.00 inches
Size of drain pipe (if present) = 8.0 inches
Number of detention orifices (if present) = 3
Size of detention orifice (if present) = 6.0 inches
Trash Rack water displacement = 38.00 CF
Concrete Present in Riser Structure =>
Total amount of concrete:
Adjust for openings:
Base of Riser = 16.667 CF
Riser Walls = 25.200 CF
Opening for barrel = 1.203 CF
Opening for drain pipe = 0.175 CF
Opening for detention orifice = 0.295 CF
JW Caldwell, PE
10/5/2010
Note: NC;N-,vds lists unit wt. of
manhole con ycte 1t 141. PC F.
Total Concrete present, adjusted for openings = 40.195 CF
Weight of concrete present = 15708 lbs
Amount of water displaced by Riser Structure =>
Displacement by concrete = 40.195 CF
Displacement by open air in riser = 44.800 CF
Displacement by trash rack = 38.000 CF
Total water displaced by riseribarrel structure = 122.995 CF
Weight of water displaced = 7675 lbs
•
Calculate amount of concrete to be added to riser =>
® 0?,e ?f66 INa4oEP
IN Wit 5T4'X-TVf-E
Safety factor to use = 1.25 {recommond 1.25 or higher)
Must add = 3886 lbs concrete for buoyancy
Concrete unit weight for use = 142 PCF (note above observation for NCP concrete)
Buoyant weight of this concrete = 79.60 PCF
Buoyant, with safety factor applied = 63.68 PCF w
Therefore, must add = 61.023 CF f concrete 1N 1V0J T?0,A-5 7-0 9{r CIO-
Jo
?G
TOWN HALL COMMONS Wetland#1 JW Caldwell, PE
PLT-10000` f 10/5/2010
Standard base described above = 16.667 jCF f concrete iN 4AS? 666
•
Therefore, base design must have = 77.689 CF of concrete
tail- e?cl?M'j o?lelS
Calculate size of base for riser assembly => ?I
Length =
Width =
Thickness =
Concrete Present =
Check validity of base as designed =>
8.000 feet
8.000 feet
15.0 inches
80.000 CF
OK
Total Water Displaced = 186.328 CF
Total Concrete Present = 103.528 CF
Total Water Displaced = 11627 lbs
Total Concrete Present = 14701 lbs
Actual safetyfactor = 1.26
is
Results of design =>
Base length = 8.00 feet
Base width = 8.00 feet
Base Thickness = 15.00 inches
CY of concrete total in base = 2.96 CY
Concrete unit weight in added base >= 142 PCF
7xft 0,vwli of fbVIOw
(elk also 13 /W?E4)
OK

•
TOWN HALL COMMONS
PLT-10000
WETLAND #1
Velocity Dissinator
NRCD Land Quality Section
Pipe Design
B.R. FINCH, PE
10/5/2010
Entering the following values will provide you with the expected outlet velocity and depth of flow in a pipe,
assuming the Manning's roughness number is constant over the entire length of the pipe.
Flow Q,o (cfs) = 2.22 Ems"' Qio "E0 U(b `1?k vLTF& , jewrtN6
Slope S (%) = 0.53 f_SvuV C coNSEKvAnvt)
Pipe Diameter Do (in) = 15
Manning's `n' = 0.013
Flow Depth (ft) = 0.60
Outlet Velocity (fps) = 3.779
•
d50 Stone Thickness
(inches) Class (inches)
3 A 9 F
6 B 22
13 B or 1 22
23 2 27
Width = La + Do
Width = 5 + 1.25
Width (ft) = 6.25 Use 7-ft
NRCD Land Quality Section
NYDOT Dissipator Design Results
Pipe Diameter (ft) = 1.25
Outlet Velocity (fps) = 3.78
Apron Length (ft) = 5.00
Use NCDOT Class `A' Rip Rap
d50 = 4"
5'L x TW x 9"Thick
0
•

FINAL STORMWATER WETLAND #2 DESIGN
CALCULATIONS
0
n
TOWN HALL COMMONS
PLT-10000
TOWN HALL COMMONS STORMWATER WETLAND #2
PLT-10000
• Stage-Storage Function
Project Name: Town Hall Commons
Designer: J. Finch, PE
Job Number: PLT-10000
Date: 10/5/2010
•
J. FINCH, PE
10/5/2010
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Volume
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (CF)
347.50 0.0 6,468
348.00 0.5 7,062 6765 3383 3383 0.51
349.00 1.5 7,920 7491 7491 10874 1.48
350.00 2.5 8,376 8148 8148 19022 2.48
351.00 3.5 8,818 8597 8597 27619 3.49
352.00 4.5 9,232 9025 9025 36644 4.53
352.50 5.0 9.426 9329 4665 41308 5.05
Storage vs. Stage
45000
40000 y = 7103.5x'0'
35000 RZ = 0.9999
C30000
V
m 25000
20000
c (% 15000
10000
5000
0
0.0 1.0 2.0 Stag.#eet) 4.0 5.0 6.0
Ks = 7103.5
b = 1.0867
0
TOWN HALL COMMONS STORMWATER WETLAND #2 J. FINCH, PE
PLT-10000 10/5/2010
• _> Stage - Storage Function
Ks= 7103.5
b = 1.0867
Zo = 347.50
•
Elevation
[feet] Storage Elevation
[cf] [acre-feet] [feet] 100-Year
[cf] [acre-feet]
347.50 0 0.000 347.50 - -
347.70 1236 0.028 347.70 - -
347.90 2624 0.060 347.90 - -
348.10 4077 0.094 348.10 - -
348.30 5574 0.128 348.30 - -
348.50 7103 0.163 348.50 - -
348.70 8660 0.199 348.65 0 0.000
348.90 10239 0.235 348.85 1574 0.036
349.10 11838 0.272 349.05 3168 0.073
349.30 13455 0.309 349.25 4781 0.110
349.50 15087 0.346 349.45 6409 0.147
349.70 16733 0.384 349.65 8052 0.185
349.90 18393 0.422 349.85 9708 0.223
350.10 20064 0.461 350.05 11377 0.261
350.30 21747 0.499 350.25 13057 0.300
350.50 23440 0.538 350.45 14747 0.339
350.70 25143 0.577 350.65 16448 0.378
350.90 26855 0.617 350.85 18158 0.417
351.10 28576 0.656 351.05 19877 0.456
351.30 30306 0.696 351.25 21604 0.496
351.50 32043 0.736 351.45 23339 0.536
351.70 33788 0.776 351.65 25082 0.576
351.90 35540 0.816 351.85 26832 0.616
352.10 37298 0.856 352.05 28590 0.656
352.30 39064 0.897 352.25 30353 0.697
352.50 40836 0.937 352.45 32124 0.737
352.50 32567 0.748
0
Type.... Vol: Elev-Volume
Name.... WETLAND #2
Page 3.04
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
USER DEFINED VOLUME RATING TABLE
•

Elevation Volume
(ft)
----------- (cu.ft)
----------
347.50 0
347.70 1236
347.90 2624
348.10 4077
348.30 5574
348.50 7103
348.70 8660
348.90 10239
349.10 11838
349.30 13455
349.50 15087
349.70 16733
349.90 18393
350.10 20064
350.30 21747
350.50 23440
350.70 25143
350.90 26855
351.10 28576
351.30 30306
351.50 32043
351.70 33788
351.90 35540
352.10 37298
352.30 39064
352.50 40836
SIN:
Bentley PondPack (10.00.027.00) 11:19 AM
Bentley Systems, Inc.
10/7/2010
Type.... Outlet Input Data
Name.... Wetland#2
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 347.50 ft
Increment = .10 ft
Max. Elev.= 352.50 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure
----------------- No.
---- Outfall
------- E1, ft
--------- E2, ft
-------
Orifice-Circular 01 ---> BA 348.650 --
352.500
Inlet Box RI ---> BA 350.000 352.500
Orifice-Circular SI ---> BA 347.500 352.500
Culvert-Circular BA ---> TW 344.500 352.500
•
TW SETUP, DS Channel
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Outlet Input Data
Name.... Wetland#2
Page 2.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = 01
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 3
Invert Elev. = 348.65 ft
Diameter = .5000 ft
Orifice Coeff. _ .600
•
Structure ID = RI
Structure Type
------------------ = Inlet Box
------------------
# of Openings = 1
Invert Elev. = 350.00 ft
Orifice Area = 16.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 16.00 ft
Weir Coeff. = 3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Structure ID = SI
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 347.50 ft
Diameter = .1042 ft
Orifice Coeff. _ .600
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Outlet Input Data
Name.... Wetland#2
Page 2.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = BA
Structure Type
------------------ = Culvert-Circular
------------------
No. Barrels = 1
Barrel Diameter = 1.2500 ft
Upstream Invert = 344.50 ft
Dnstream Invert = 341.35 ft
Horiz. Length = 35.00 ft
Barrel Length = 35.14 ft
Barrel Slope = .09000 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = 3.0000
Kb = .023225
Kr = 3.0000
HW Convergence = .001
•
•
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) = 1.115
T2 ratio (HW/D) = 1.262
Slope Factor = -.500
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/- ft
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 345.89 ft ---> Flow = 4.80 cfs
At T2 Elev = 346.08 ft ---> Flow = 5.49 cfs
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Outlet Input Data
Name.... Wetland#2
Page 2.04
0 File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
11
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****

•
WS Elev, Total Q Notes
-------- -------- ------ -- Converge ---------- ---- -----------
Elev. Q TW El ev Error
ft
-------- cfs
------- ft
------ +/-ft
-- ----- - Contributing Structures
-------------------------
347.50 .00 Free Outfall (no Q: 01 ,RI,SI,BA)
347.60 .01 Free Outfall SI,BA (no Q: Ol,RI)
347.70 .02 Free Outfall SI,BA (no Q: O1,RI)
347.80 .02 Free Outfall SI,BA (no Q: Ol,RI)
347.90 .02 Free Outfall SI,BA (no Q: O1,RI)
348.00 .03 Free Outfall SI,BA (no Q: O1,RI)
348.10 .03 Free Outfall SI,BA (no Q: O1,RI)
348.20 .03 Free Outfall SI,BA (no Q: O1,RI)
348.30 .04 Free Outfall SI,BA (no Q: O1,RI)
348.40 .04 Free Outfall SI,BA (no Q: O1,RI)
348.50 .04 Free Outfall SI,BA (no Q: O1,RI)
348.60 .04 Free Outfall SI,BA (no Q: O1,RI)
348.65 .04 Free Outfall SI,BA (no Q: O1,RI)
348.70 .06 Free Outfall 01,SI,BA (no Q: RI)
348.80 .90 Free Outf_all 01,SI,BA (no Q: RI)
348.90 .45 Free Outfali 01,SI,BA (no Q: RI)
349.00 .80 Free Outfall 01,SI,BA (no Q: RI)
349.10 1.20 Free Outfall O1,SI,BA (no Q: RI)
349.20 1.60 Free Outfall Ol,SI,BA (no Q: RI)
349.30 1.85 Free Outfall 01,SI,BA (no Q: RI)
349.40 2.06 Free Outfall 01,SI,BA (no Q: RI)
349.50 2.25 Free Outfall O1,SI,BA (no Q: RI)
349.60 2.43 Free Outfall 01,SI,BA (no Q: RI)
349.70 2.59 Free Outfall 01,SI,BA (no Q: RI)
349.80 2.75 Free Outfall 01,SI,BA (no Q: RI)
349.90 2.90 Free Outfall 01,SI,BA (no Q: RI)
350.00 3.03 Free Outfall 01,SI,BA (no Q: RI)
350.10 4.69 Free Outfall 01,RI,SI,BA
350.20 7.58 Free Outfall 01,RI,SI,B A
350.30 9.82 Free Outfall 01,RI,SI,B A
350.40 10.51 Free Outfall 01,RI,SI,B A
350.50 10.63 Free Outfall RI,BA (no Q: 01,SI)
350.60 10.75 Free Outfall RIBA (no Q: O1,SI)
350.70 10.86 Free Outfall RIBA (no Q: 01,SI)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Composite Rating Curve
Name.... wetland#2
Page 2.22
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:

17?
WS Elev, Total Q
----------------
Elev. Q
ft cfs
350.80 10.98
350.90 11.09
351.00 11.20
351.10 11.31
351.20 11.42
351.30 11.53
351.40 11.64
351.50 11.74
351.60 11.85
351.70 11.95
351.80 12.05
351.90 12.15
352.00 12.26
352.10 12.36
352.20 12.45
352.30 12.55
352.40 12.65
352.50 12.75
***** COMPOSITE OUTFLOW SUMMARY ****
-------- Converge
TW Elev Error
ft +/-ft
-------- -----
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Notes
-----------------------
Contributing Structures
RI,BA (no Q: Ol,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RIBA (no Q: 01,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
RIBA (no Q: 01,SI)
RIBA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: nl,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: 01,SI)
SIN:. Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:03 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.20
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE Jo - qg
Project Title: Town Hall Commons arw
Project Comments:
***** COMPGoITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
•
•
WS Elev, Total Q Notes
-------- -------- -------- Converge ---------- --- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-------- +/-ft
- Contributi ng Structures

347.50
.00
343.06 ---- -
.000 ----------
(no Q: 01 ---------------
,RI,SI,BA)
347.60 .01 343.06 .000 SI,BA (no Q: O1,RI)
347.70 .02 343.06 .000 SI,BA (no Q: O1,RI)
347.80 .02 343.06 .000 SI,BA (no Q: O1,RI)
347.90 .02 343.06 .000 SI,BA (no Q: O1,RI)
348.00 .03 343.06 .000 SI,BA (no Q: O1,RI)
348.10 .03 343.06 .000 SI,BA (no Q: O1,RI)
348.20 .03 343.06 .000 SI,BA (no Q: O1,RI)
348.30 .04 343.06 .000 SI,BA (no Q: O1,RI)
348.40 04 343.06 .000 SI,BA (no Q: O1,RI)
348.50 .04 343.06 .000 SI,BA (no Q: O1,RI)
348.60 .04 343.06 .000 SI,BA (no Q: O1,RI)
348.65 .04 343.06 .000 SI,BA (no Q: O1,RI)
348.70 .06 343.06 .000 01,SI,BA (no Q: RI)
348.80 .20 343.06 .000 01,SI,BA (no Q: RI)
348.90 .45 343.06 .000 01,SI,BA (no Q: RI)
349.00 .80 343.06 .000 01,SI,BA (no Q: RI)
349.10 1.20 343.06 .000 01,SI,BA (no Q: RI)
349.20 1.60 343.06 .000 01,SI,BA (no Q: RI)
349.30 1.85 343.06 .000 01,SI,BA (no Q: RI)
349.40 2.06 343.06 .000 01,SI,BA (no Q: RI)
349.50 2.25 343.06 .000 01,SI,BA (no Q: RI)
349.60 2.43 343.06 .000 01,SI,BA (no Q: RI)
349.70 2.59 343.06 .000 01,SI,BA (no Q: RI)
349.80 2.75 343.06 .000 01,SI,BA (no Q: RI)
349.90 2.90 343.06 .000 01,SI,BA (no Q: RI)
350.00 3.03 343.06 .000 01,SI,BA (no Q: RI)
350.10 4.69 343.06 .000 01,RI,SI,BA
350.20 7.58 343.06 .000 01,RI,SI,BA
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:12 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
WS Elev, Total Q
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.

•
Elev. Q
ft
-------- cfs

350.30 -------
9.82
350.40 10.51
350.50 10.63
350.60 10.75
350.70 10.86
350.80 10.98
350.90 11.09
351.00 11.20
351.10 11.31
351.20 11.42
351.30 11.53
351.40 11.64
351.50 11.74
351.60 11.85
351.70 11.95
351.80 12.05
351.90 12.15
352.00 12.26
352.10 12.36
352.20 12.45
352.30 12.55
352.40 12.65
352.50 12.75
***** COMPOSITE OUTFLOW SUMMARY ****
Notes
-------- Converge -------------------------
ft +/-ft
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
343.06 .000
SIN:
Bentley PondPack (10.00.027.00)
Contributing Structures
O1,RI,SI,BA
O1,RI,SI,BA
RIBA (no Q: O1,SI)
RIBA (no Q: 01,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: O1,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: 01.,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: O1,SI)
RI,BA (no Q: O1,SI)
RI,BA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RIBA (no Q: O1,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: O1,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
RI,BA (no Q: 01,SI)
11:12 AM
Bentley Systems, Inc.
10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.20
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons- .
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY *^-r*
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
-------- -------- -------- Converge
----------
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
------- +/-ft Contributi ng Structures

347.50
.00 -
347.06 ----- -
.000 -------------------------
(no Q: 01,RI,SI,BA)
347.60 .01 347.06 .000 SI,BA (no Q: O1,RI)
347.70 .02 347.06 .000 SI,BA (no Q: O1,RI)
347.80 .02 347.06 .000 SI,BA (no Q: O1,RI)
347.90 .02 347.06 .000 SI,BA (no Q: 01,RI)
348.00 .03 347.06 .000 SI,BA (no Q: Ol,RI)
348.10 .03 347.06 .000 SI,BA (no Q: Ol,RI)
348.20 .03 347.06 .000 SI,BA (no Q: O1,RI)
348.30 .04 347.06 .000 SI,BA (no Q: 01,RI)
•
348.40 .04 347.06 .000 ST,BA (no n: 01,RI)
348.50 .04 347.06 .000 SI,BA (no Q: 01,RI)
348.60 .04 347.06 .000 SI,BA (no Q: O1,RI)
348.65 .04 347.06 .000 SI,BA (no Q: O1,RI)
348.70 .06 347.06 .000 01,SI,BA (no Q: RI)
348.80 .20 347.06 .000 O1,SI,BA (no Q: RI)
348.90 .45 347.06 .000 O1,SI,BA (no Q: RI)
349.00 .80 347.06 .000 01,SI,BA (no Q: RI)
349.10 1.20 347.06 .000 01,SI,BA (no Q: RI)
349.20 1.61 347.06 .000 01,SI,BA (no Q: RI)
349.30 1.85 347.06 .000 01,SI,BA (no Q: RI)
349.40 2.06 347.06 .000 01,SI,BA (no Q: RI)
349.50 2.25 347.06 .000 01,SI,BA (no Q: RI)
349.60 2.43 347.06 .000 O1,SI,BA (no Q: RI)
349.70 2.59 347.06 .000 O1,SI,BA (no Q: RI)
349.80 2.75 347.06 .000 O1,SI,BA (no Q: RI)
349.90 2.90 347.06 .000 01,SI,BA (no Q: RI)
350.00 3.04 347.06 .000 01,SI,BA (no Q: RI)
350.10 4.68 347.06 .000 01,RI,SI,BA
350.20 6.86 347.06 .000 01,RI,SI,BA

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:24 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
-------- -------- -------- Converge ------ ----- -- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft Contributing Structures

350.30
8.07 --------
347.06 -----
.000 --------------
01,RI,SI,BA ------------
350.40 8.20 347.06 .000 01,RI,SI,BA
350.50 8.32 347.06 .000 RI,BA (no Q: O1,SI)
350.60 8.44 347.06 .000 RI,BA (no Q: O1,SI)
350.70 8.56 347.06 .000 RIBA (no Q: O1,SI)
350.80 8.68 347.06 .000 RIBA (no Q: O1,SI)
350.90 8.79 347.06 .000 RIBA (no Q: 01,SI)
351.00 8.90 347.06 .000 RIBA (no Q: O1,SI)
• 351.10
351.20 9.02
9.13 347.06
347.06 .000
.000 RI,BA
RI,BA (no
(no Q:
Q: Ol,SI)
O1,SI)
351.30 9.24 347.06 .000 RIBA (no Q: O1,SI)
351.40 9.35 347.06 .000 RIBA (no Q: O1,SI)
351.50 9.45 347.06 .000 RI,BA (no Q: O1,SI)
351.60 9.56 347.06 .000 RI,BA (no Q: O1,SI)
351.70 9.66 347.06 .000 RIBA (no Q: O1,SI)
351.80 9.77 347.06 .000 RIBA (no Q: 01,SI)
351.90 9.87 347.06 .000 RIBA (no Q: 01,SI)
352.00 9.97 347.06 .000 RIBA (no Q: Ol,SI)
352.10 10.07 347.06 .000 RIBA (no Q: Ol,SI)
352.20 10.17 347.06 .000 RIBA (no Q: Ol,SI)
352.30 10.27 347.06 .000 RIBA (no Q: Ol,SI)
352.40 10.37 347.06 .000 RI,BA (no Q: O1,SI)
352.50 10.46 347.06 .000 RI,BA (no Q: O1,SI)
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:24 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
•
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .001 (+/- ft)
FLOW PATH: Elev= 349.8; Branch: SI-BA-TW
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
•
•
Page 2.20
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
WS Elev, Total Q
----------------
Elev. Q
ft cfs
347.50
347.60
347.70
347.80
347.90
348.00
348.10
348.20
348.30
348.40
348.50
348.60
348.65
348.70
348.80
348.90
349.00
349.10
349.20
349.30
349.40
349.50
349.60
349.70
349.80
349.90
350.00
350.10
TW Elev
ft
100#0-to WrW
(oAFicG uNCUx?EO?
Notes
Converge -------------------------
Error
+/-ft Contributing Structures
----- --------------------------
.00 347.70 .000 (no Q: 01,RI,SI,BA)
.00 347.70 .000 (no Q: 01 ,RI,SI,BA)
.00 347.70 .000 (no Q: 01 ,RI,SI,BA)
.01 347.70 .000 SI,BA (no Q: Ol,RI)
.02 347.70 .000 SI,BA (no Q: Ol,RI)
.02 347.70 .000 SI,BA (no Q: 01,RI)
.03 347.70 .000 SI,BA (no Q: Ol,RI)
.03 347.70 .000 SI,BA (no Q: O1,RI)
.03 347.70 .000 SI,BA (no 0. 01,RT)
.03 347.70 .000 SI,BA (no Q: Ol,RI)
.04 347.70 .000 SI,BA (no Q: Ol,RI)
.04 347.70 .000 SI,BA (no Q: Ol,RI)
.04 347.70 .000 SI,BA (no Q: Ol,RI)
.06 347.70 .000 Ol,SI,BA (no Q: RI)
.20 347.70 .000 01,SI,BA (no Q: RI)
.45 347.70 .000 01,SI,BA (no Q: RI)
.79 347.70 .001 O1,SI,BA (no Q: RI)
1.20 347.70 .001 01,SI,BA (no Q: RI)
1.60 347.70 .000 O1,SI,BA (no Q: RI)
1.84 347.70 .000 01,SI,BA (no Q: RI)
2.05 347.70 .000 01,SI,BA (no Q: RI)
2.25 347.70 .000 01,SI,BA (no Q: RI)
2.42 347.70 .000 01,SI,BA (no Q: RI)
2.59 347.70 .000 01,SI,BA (no Q: RI)
2.74 347.70 .001 01,SI,BA (no Q: RI)
2.89 347.70 .000 O1,SI,BA (no Q: RI)
3.03 347.70 .000 O1,SI,BA (no Q: RI)
4.67 347.70 .000 01,RI,SI,B A
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:37 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .001 (+/- ft)
FLOW PATH: Elev= 349.8; Branch: SI-BA-TW
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
•
•
WS Elev, Total Q Notes
-------- -------- -------- Converge ------ ----- -- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-------- +/-ft
----- - Contributing
---
- Structures

350.20
6.33
347.70
.000 --
-------
01,RI,SI,BA ------------
350.30 7.23 347.70 .000 RIBA (no Q: O1,SI)
350.40 7.37 347.70 .000 RI,BA (no Q: 01,SI)
350.50 7.51 347.70 .000 RIBA (no Q: O1,SI)
350.60 7.64 347.70 .000 RIBA (no Q: O1,SI)
350.70 7.77 347.70 .000 RI,BA (no Q: O1,SI)
350.80 7.90 347.70 .000 RIBA (no Q: O1,SI)
350.90 8.02 347.70 .000 RIBA (no Q: 01,SI)
351.00 8.15 347.70 .000 RIBA (no Q: 01,SI)
351.10 8.27 347.70 .000 RIBA (no Q: O1,SI)
351.20 8.39 347.70 .000 RI,BA (no Q: O1,SI)
351.30 8.51 347.70 .000 RIBA (no Q: 01,SI)
351.40 8.63 347.70 .000 RI,BA (no Q: O1,SI)
351.50 8.74 347.70 .000 RI,BA (no Q: O1,SI)
351.60 8.86 347.70 .000 RIBA (no Q: Ol,SI)
351.70 8.97 347.70 .000 RIBA (no Q: O1,SI)
351.80 9.08 347.70 .000 RIBA (no Q: 01,SI)
351.90 9.19 347.70 .000 RI,BA (no Q: O1,SI)
352.00 9.30 347.70 .000 RIBA (no Q: 01,SI)
352.10 9.41 347.70 .000 RI,BA (no Q: O1,SI)
352.20 9.52 347.70 .000 RIBA (no Q: O1,SI)
352.30 9.62 347.70 .000 RIBA (no Q: O1,SI)
352.40 9.72 347.70 .000 RI,BA (no Q: O1,SI)
352.50 9.83 347.70 .000 RI,BA (no Q: O1,SI)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:37 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
•
Page 2.13
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
•
•
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q
----------------
Elev. Q
ft cfs
348.65
348.75
348.85
348.95
349.05
349.15
349.25
349.35
349.45
349.55
349.65
349.75
349.85
349.95
350.00
350.05
350.15
350.25
350.35
350.45
350.55
350.65
350.75
350.85
350.95
351.05
351.15
351.25
351.35
.00
.07
.27
.56
.94
1.41
1.68
1.90
2.10
2.29
2.46
2.62
2.76
2.90
2.97
3.58
5.47
6.91
7.21
7.34
7.48
7.61
7.74
7.87
8.00
8.12
8.25
8.37
8.49
Notes
-------- Converge -------------------------
TTT Pl o?? 1'. rr?r
ft +/-ft
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347,77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
347.77 .000
Contributing Structures
(no Q: RI,OI,BA)
01,BA (no Q: RI)
01,BA (no Q: RI)
O1,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,3A (no Q: RI)
O1,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
01,BA (no Q: RI)
RI,OI,BA
RI,OI,BA
RI,OI,BA
RI,OI,BA
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RIBA (no Q: 01)
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RI,BA (no Q: 01)
RIBA (no Q: 01)
? !ol)-Yte 7W -W
.. &.Of- .4 Oak Fick
(6M95r-LTDr- i
S/N:
Bentley PondPack (10.00.027.00)
3:58 PM
Bentley Systems, Inc.
10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#2
Page 2.14
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
is
•
WS Elev, Total Q Notes
-------- -------- -------- Converge
------
----
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-------- +/-ft Contributing Structures

351.45
8.61
347.77 ----- -
.000 ------
RIBA ----
(no ---
Q: ------------
01)
351.55 8.72 347.77 .000 RI,BA (no Q: O1)
351.65 8.84 347.77 .000 RIBA (no Q: O1)
351.75 8.95 347.77 .000 RIBA (no Q: O1)
351.85 9.06 347.77 .000 RI,BA (no Q: O1)
351.95 9.17 347.77 .000 RI,BA (no Q: O1)
352.05 9.28 347.77 .000 RI,BA (no Q: O1)
352.15 9.39 347.77 .000 RIBA (no Q: O1)
352.25 9.50 347.77 .000 RI,BA (no Q: O1)
352.35 9.60 347.77 .000 RIBA (no Q: O1)
352.45 9.70 347.77 .000 RI,BA (no Q: O1)
352.50 9.76 347.77 .000 RIBA (no Q: O1)
S/N:
Bentley PondPack (10.00.027.00)
3:58 PM
Bentley Systems, Inc.
10/5/2010
•
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2

TOWN HALL COMMONS STORA WATER WETLAND #2
PLT-10000 SIZING CALCULATIONS
• _> Determination of Water Quality Volume " v)
WQ v = (P) (R v)(A)/12
where,
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total area, A = 3.00 acres
Impervious area = 1.26 acres
Percent impervious cover, I = 42.0 %
Rainfall, P = 1.0 inches
Calculated values:
Rv = 0.43
WQv= 0.11 acre-ft
= 4656 cf.
_> Storntwaier Wetland Required Surface Area Calculation
WQ Volume = 4656 cf.
Maximum Ponding Depth = 12 inches
Surface Area Required at Normal Pool = 4656 SF
_> Associated Pond Depth to Stormwater Wedand
Ks = 7103.5
b = 1.0867
V = 4656
Normal Pool Elevation = 347.50 feet
WQ Elevation = 348.18 feet
=> Determination of 1-Yr Pre-Post Volume Storage Provided by Facility
Input data:
Control Orifice (3 x 6" Dia) Invert = 348.65 feet
Normal Pool Elevation = 347.50 feet
Calculated values:
1-Yr Pre-Dev Runoff Volume (To Wetland #2) = 10,559 cf
1-Yr Post-Dev Runoff Volume (To Wetland #2) = 18,537 cf
1-Yr Pre-Post Volume Difference = 7,978 cf
Ks = 7103.5
b = 1.0867
• Storage Provided Orifice Invert = 8,269 feet
J. FINCH, PE
10/5/2010
•
TOWN HALL COMMONS
PLT-10000
SIPHON DESIGN
WETLAND #2 -1" WQ VOLUME
D orifice = 1.25 inch
# orifices = 1
Ks = 7104.4
b = 1.086
Cd siphon = 0.60
Normal Pool Elevation = 347.50 feet
Orifice Invert = 347.00 feet
1" WQ Volume = 4656 cf
WSEL @ 1" Runoff Volume = 348.18 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.393 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.009 sf
Q = 0.0257 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 2.10 days
•
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the 1" storm runoff, with a required time of about 2.10 days.
B.R. FINCH, PE
10/4/2010

TOWN HALL COMMONS WETLAND #2 -1 YR PRE-POST VOLUME
PLT-10000
• SIPHON DESIGN
D orifice = 1.25 inch
# orifices = 1
Ks = 7103.5
b = 1.0867
Cd siphon = 0.60
Normal Pool Elevation = 347.50 feet
Orifice Invert = 347.00 feet
1" Pre-Post Volume = 8269 cf
WSEL @ 1-Yr Pre-Post Volume = 348.65 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.550 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.009 sf
Q = 0.0304 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 3.14 days
•
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the difference in 1-Yr Pre-Post Runoff Volume, with a required time of about 3.14 days.
B.R. FINCH, PE
10/5/2010
E

WT 4,

PIPE DESIGN SPECIFICATIONS:
1. ASTM C 76-Latest
Class III, IV, & V
2. AASHTO M-1704Latest
JOINT DESIGN SPECIFICATIONS:
1. ASTM C-443-Latest
2. ASTM C-361-Latest
3. Joint Type-114 with "O" Ring
Rubber Gaskets.
x
i a d
a d
?- d JT OD
- GS .., ? _ d ° GL TSB ? ? •?.)
t tl ad °
C 9 d
i? a Q
d
C d d d
a
d 10 ,4 AST TD GD
d
° a° GW d
A
01
ID GAP

ID
WT
JT
GD
TD
AS
OI
GW
GS
GL
TS
AST
X
OD Pounds
Per
Foot
Plant
12" B-2114 31/2" 15.260" 14.725" .063" 14.606" .377" 11/16" 1" 1" 1/8" 5 3/4" 19 5116" 123 VB
15" C-3 31/2" 18.759" 18.224" .063" 18.105" .377" 11/16" 1" 1" 1/8" 51/2" 23 5116" 191 VB
18" C-3 1/4 31/2" 21.787" 21.252" .063" 21.133" .377" 11/16" 1" 1" 1/8" 6" 261/2' 249 VB
24" C- 3 3/4 3 7/8" 29.138" 28.950" .063" 28.408" .400 7/8" 13/16" 1" 3132" 6" 351/2" 367 VB
•i
Oldcastle Precast
N.C. Products
920 Withers Road Raleigh, NC.27603
Phone: [phone] Fox: 919.772.1209
N.T.S.
8'='0" RINGABS
FILE NAME: 450SPC812RTG2_DET.DWG
ISSUE DATE: JULY, 2008 i
Reinforced "O" RING
Modified Bell & Spigot
Copyright 0 2005 Omammi?prmst,im.
TOWN HALL COMMONS Wetland#2 JW Caldwell, PE
PLT-10000 10/5/2010
•
Spuare Riser/Barrel Anti-Flotation Calculation Sheet
Input Data =>
Inside length of riser = 4.00 feet
Inside width of riser = 4.00 feet
Wall thickness of riser = 6.00 inches
Base thickness of riser = 8.00 inches
Base length of riser = 5.00 feet
Base width of riser = 5.00 feet
Inside height of Riser = 5.50 feet
Concrete unit weight = 142.0 PCF
OD of barrel exiting manhole = 21.00 inches
Size of drain pipe (if present) = 8.0 inches
Number of detention orifices (if present) = 3
Size of detention orifice (if present) = 6.0 inches
Trash Rack water displacement = 38.00 CF
Concrete Present in Riser Structure =>
Total amount of concrete:
•
Adjust for openings:
Base of Riser = 16.667 CF
Riser Walls = 49.500 CF
Opening for barrel = 1.203 CF
Opening for drain pipe = 0.175 CF
Opening for detention orifice = 0295 CF
Note: \C Products lists unit 1t1. of
manhole can -ete at 1.42 PCF.
Total Concrete present, adjusted for openings = 64.495 CF
Weight of concrete present = 9158 lbs
Amount of water displaced by Riser Structure =>
Displacement by concrete = 64.495 CF
Displacement by open air in riser = 88.000 CF
Displacement by trash rack = 38.000 CF
Total water displaced by riser/barrel structure = 190.495 CF
Weight of water displaced = 11887 lbs
Calculate amount of concrete to be added to riser =>
K130e 666- (W-4,-OW l N
P 5W- 5-W-7aC t^'EI6Mfi
066PIT-
Safety factor to use = 1.25 (recommend t.25 er hi gher)
Must add = 5700 lbs concrete for buoyancy
Concrete unit weight for use = 142 PCF (note above observation for NCP concrete)
Buoyant weight of this concrete = 79.60 PCF
Buoyant, with safety factor applied = 63.68 PCF
• Therefore, must add = 1concrete
VII IW p? C4+? ?, /l;cv6p
IV ",91 va-- -P ?`? pw- W
TOWN HALL COMMONS Wetland#2 JW Caldwell, PE
PLT-10000 fly*V-rof GRCl? 10/5/2010
Standard base described above = 16.667 CF of concrete
• Therefore, base design must have = 106.182 C of concrete
E
Td j,?,E?Gf a1=?21 SEA 1
Calculate size of base for riser assembly => h
L (??cw,otr?f& 0 Dill z
Length = 8.000 feet
Width = 8.000 feet
Thickness = 20.0 inches
Concrete Present = 106.667 CF
Check validity of base as designed =>
Total Water Displaced = 280.495 CF
Total Concrete Present = 154.495 CF
Total Water Displaced = 17503 lbs
Total Concrete Present = 21938 lbs
Actual safetyfactor = 1.25
Results of design =>
•
fib- t'Ejw o? 0?
P o 6
o''rzl5?? B/t
I S I??
OK
Base length = 8.00 feet
Base width = 8.00 feet
Base Thickness = 20.00 inches
CY of concrete total in base = 3.95 CY
Concrete unit weight in added base >= 142 PCF
OK
0
•

FINAL STORMWA TER WETLAND #3 DESIGN
CALCULATIONS
•
0
TOWN HALL COMMONS
PLT-10000
TOWN HALL COMMONS STORMWATER WETLAND #3 J. FINCH, PE
PLT-10000 10/5/2010
• Stage-Storage Function
Project Name: Town Hall Commons
Designer: J. Finch, PE
Job Number: PLT-10000
Date: 10/5/2010
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Volume
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (CF)
345.50 0.0 5,195
346.00 0.5 5,635 5415 2708 2708 0.50
347.00 1.5 6,273 5954 5954 8662 1.48
348.00 2.5 6,590 6432 6432 15093 2.48
349.00 3.5 6,910 6750 6750 21843 3.49
350.00 4.5 7,234 7072 7072 28915 4.53
350.25 4.8 7.316 7275 1819 30734 4.79
•
0
Ks = 5666.2
b = 1.0793
TOWN HALL COMMONS STORMWATER WETLAND #3 J. FINCH, PE
PLT-10000 10/5/2010
• _> Stage - Storage Function
Ks = 5666.2
b = 1.0793
Zo = 345.50
•
Elevation
[feet] Storage Elevation
[cf] [acre-feet] [feet] 100-Year
[cf] [acre-feet]
345.50 0 0.000 345.50 - -
345.70 997 0.023 345.70 - -
345.90 2108 0.048 345.90 - -
346.10 3265 0.075 346.10 - -
346.30 4453 0.102 346.30 - -
346.50 5666 0.130 346.50 - -
346.70 6898 0.158 346.70 - -
346.90 8147 0.187 346.90 - -
347.00 8777 0.201 347.00 0 0.000
347.20 10047 0.231 347.20 1269 0.029
347.40 11328 0.260 347.40 2551 0.059
347.60 12620 0.290 347.60 3843 0.088
347.80 13922 0.320 347.80 5145 0.118
348.00 15233 0.350 348.00 6456 0.148
348.20 16552 0.380 348.20 7775 0.178
348.40 17880 0.410 348.40 9103 0.209
348.60 19214 0.441 348.60 10437 0.240
348.80 20555 0.472 348.80 11778 0.270
349.00 21903 0.503 349.00 13126 0.301
349.20 23257 0.534 349.20 14480 0.332
349.40 24617 0.565 349.40 15840 0.364
349.60 25982 0.596 349.60 17205 0.395
349.80 27352 0.628 349.80 18575 0.426
350.00 28728 0.660 350.00 19951 0.458
350.20 30108 0.691 350.20 21331 0.490
350.25 30454 0.699 350.25 21677 0.498

Type.... Vol: Elev-Volume
Name.... WETLAND #3
•
Page 3.05
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
USER DEFINED VOLUME RATING TABLE
•
•
Elevation Volume
(ft)
----------- (cu.ft)
-----

345.50 -----
0
345.70 997
345.90 2108
346.10 3265
346.30 4453
346.50 5666
346.70 6898
346.90 8147
347.00 8777
347.20 10047
347.40 11328
347.60 12620
347.80 13922
348.00 15233
348.20 16552
348.40 17880
348.60 19214
348.80 20555
349.00 21903
349.20 23257
349.40 24617
349.60 25982
349.80 27352
350.00 28728
350.20 30108
350.25 30454
SIN:
Bentley PondPack (10.00.027.00) 11:19 AM
Bentley Systems, Inc.
10/7/2010
Type.... Outlet Input Data
Name.... Wetland#3
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments :
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 345.50 ft
Increment = .10 ft
Max. Elev.= 350.25 ft
**********************************************
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
-----------------
Orifice-Circular ----
01 -------
---> BA ---------
347.000 ---------
350.250
Inlet Box RI ---> BA 348.500 350.250
Orifice-Circular SI ---> BA 345.500 350.250
Culvert-Circular BA ---> TW 341.000 350.250
. TW.SETUP, DS Channel.
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Outlet Input Data
Name.... Wetland#3
•
Page 2.02
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = 01
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 3
Invert Elev. = 347.00 ft
Diameter = 1.0000 ft
Orifice Coeff. _ .600
•
Structure ID = RI
Structure Type =
------------------- Inlet Box
-----------------
# of Openings = 1
Invert Elev. = 348.50 ft
Orifice Area = 25.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 20.00 ft
Weir Coeff. = 3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Structure ID = SI
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 345.50 ft
Diameter = .1042 ft
Orifice Coeff. _ .600
•
SIN:
Bentley PondPack (10.00.027.00) 11:13 AM
Bentley Systems, Inc.
10/5/2010
Type.... Outlet Input Data
Name.... Wetland#3
Page 2.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = BA
Structure Type = Culvert-Circular
-------------------
No. Barrels = -----------
1 ------
Barrel Diameter = 2.0000 ft
Upstream Invert = 341.00 ft
Dnstream Invert = 340.15 ft
Horiz. Length = 45.00 ft
Barrel Length = 45.01 ft
Barrel Slope = .01889 ft/ft
OUTLET CONTROL DATA ...
Mannings n = .0130
Ke = 3.0000 (forward entrance loss)
Kb = .012411 (per ft of full flow)
Kr = 3.0000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA. ..
• Equation form 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) = 1.151
T2 ratio (HW/D) = 1.297
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 343.30 ft ---> Flow = 15.55 cfs
At T2 Elev = 343.59 ft ---> Flow = 17.77 cfs
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMhIARY ****
Cl
•
WS Elev, Total Q Notes
-------- -------- ----- --- Converge
----------
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
-------- ----- Contributing Structures

345.50
.00
Free
Outfall -----------
(no Q: 01 ---
,RI ------------
,SI,BA)
345.60 .01 Free Outfall SI,BA (no Q: O1,RI)
345.70 .02 Free Outfall SI,BA (no Q: O1,RI)
345.80 .02 Free Outfall SI,BA (no Q: O1,RI)
345.90 .02 Free Outfall SI,BA (no Q: O1,RI)
346.00 .03 Free Outfall SI,BA (no Q: O1,RI)
346.10 .03 Free Outfall SI,BA (no Q: O1,RI)
346.20 .03 Free Outfall SI,BA (no Q: Ol,RI)
346.30 .04 Free Outfall SI,BA (no Q: O1,RI)
346.40 .04 Free Outfall SI,BA (no Q: O1,RI)
346.50 .04 Free Outfall SI,BA (no Q: Ol,RI)
346.60 .04 Free Outfall SI,BA (no Q: O1,RI)
346.70 .04 Free Outfall SI,BA (no Q: O1,RI)
346.80 .05 Free Outfall SI,BA (no Q: O1,RI)
346.90 .05 Free Outfall SI,BA (no Q: O1,RI)
347.00 .05 Free Outfall SI,BA (no Q: O1,RI)
347.10 .15 Free Outfall 01,SI,BA (no Q: RI)
347.20 .45 Free Outfall 01,SI,BA (no Q: RI)
347.30 .93 Free Outfall 01,SI,BA (no Q: RI)
347.40 1.56 Free Outfall 01,SI,BA (no Q: RI)
347.50 2.34 Free Outfall 01,SI,BA (no Q: RI)
347.60 3.27 Free Outfall O1,SI,BA (no Q: RI)
347.70 4.29 Free Outfall 01,SI,BA (no Q: RI)
347.80 5.40 Free Outfall 01,SI,BA (no Q: RI)
347.90 6.58 Free Outfall 01,SI,BA (no Q: RI)
348.00 8.08 Free Outfall 01,SI,BA (no Q: RI)
348.10 8.85 Free Outfall 01,SI,BA (no Q: RI)
348.20 9.56 Free Outfall 01,SI,BA (no Q: RI)
348.30 10.21 Free Outfall 01,SI,BA (no Q: RI)
348.40 10.83 Free Outfall 01,SI,BA (no Q: RI)
348.50 11.41 Free Outfall 01,SI,BA (no Q: RI)
348.60 13.86 Free Outfall 01,RI,SI,BA
348.70 17.85 Free Outfall 01,RI,SI,BA
348.80 22.84 Free Outfall 01,RI,SI,BA
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.22
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
•
•
WS Elev, Total Q Notes
-------- -------- ----- --- Converge
------
-------
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
-------- ----- Contributing Structures

348.90
26.87
Free -
Outfall ------
01,RI, -------
SI,BA ------------
349.00 28.99 Free Outfall 01,RI, SI,BA
349.10 30.45 Free Outfall 01,RI, SI,BA
349.20 30.87 Free Outfall RI,BA (no Q: Ol,SI)
349.30 31.14 Free Outfall RI,BA (no Q: 01,SI)
349.40 31.40 Free Outfall RI,BA (no Q: Ol,SI)
349.50 31.67 Free Outfall RI,BA (no Q: O1,SI)
349.60 31.93 Free Outfall RI,BA (no Q: Ol,SI)
349.70 32.19 Free Outfall RI,BA (no Q: 01,SI)
349.80 32.45 Free Outfall RIBA (no Q: O1,SI)
349.90 32.70 Free Outfall RI,BA (no Q: Ol,SI)
350.00 32.95 Free Outfall RIBA (no Q: 01,SI)
350.10 33.20 Free Outfall RI,BA (no Q: 01,SI)
350.20 33.69 Free Outfall RI,BA (no Q: 01,SI)
350.25 33.76 Free Outfall RI,BA (no Q: 01,SI)
SIN:
Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.20
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMNiiiA ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
-------- -------- -------- Converge ---------- ---- -----------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-----
- +/-ft Contributing Structures

345.50
.00 -
-
341.96 ----- -
.000 -------------------------
(no Q: 01,RI,SI,BA)
345.60 .01 341.96 .000 SI,BA (no Q: O1,RI)
345.70 .02 341.96 .000 SI,BA (no Q: O1,RI)
345.80 .02 341.96 .000 SI,BA (no Q: O1,RI)
345.90 .02 341.96 .000 SI,BA (no Q: O1,RI)
346.00 .03 341.96 .000 SI,BA (no Q: O1,RI)
346.10 .03 341.96 .000 SI,BA (no Q: 01,RI)
346.20 .03 341.96 .000 SI,BA (no Q: O1,RI)
346.30 .04 341.96 .000 SI,BA (no Q: O1,RI)
• 346.40 .04 341.96 ..000 SI,BA (no Q: 01,RI)
346.50 .04 341.96 .000 SI,BA (no Q: O1,RI)
346.60 .04 341.96 .000 SI,BA (no Q: 01,RI)
346.70 .04 341.96 .000 SI,BA (no Q: 01,RI)
346.80 .05 341.96 .000 SI,BA (no Q: Ol,RI)
346.90 .05 341.96 .000 SI,BA (no Q: 01,RI)
347.00 .05 341.96 .000 SI,BA (no Q: 01,RI)
347.10 .15 341.96 .000 01,SI,BA (no Q: RI)
347.20 .45 341.96 .000 01,SI,BA (no Q: RI)
347.30 .93 341.96 .000 01,SI,BA (no Q: RI)
347.40 1.56 341.96 .000 01,SI,BA (no Q: RI)
347.50 2.34 341.96 .000 01,SI,BA (no Q: RI)
347.60 3.27 341.96 .000 Ol,SI,BA (no Q: RI)
347.70 4.29 341.96 .000 01,SI,BA (no Q: RI)
347.80 5.40 341.96 .000 01,SI,BA (no Q: RI)
347.90 6.58 341.96 .000 01,SI,BA (no Q: RI)
348.00 8.08 341.96 .000 01,SI,BA (no Q: RI)
348.10 8.85 341.96 .000 O1,SI,BA (no Q: RI)
348.20 9.56 341.96 .000 01,SI,BA (no Q: RI)
348.30 10.21 341.96 .000 01,SI,BA (no Q: RI)
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
-------- -------- -------- Converge ------------- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft Contributing Structures

348.40
10.83 --------
341.96 ----- -
.000 -------------
01,SI,BA (no ------------
Q: RI)
348.50 11.41 341.96 .000 O1,SI,BA (no Q: RI)
348.60 13.86 341.96 .000 O1,RI,SI,BA
348.70 17.85 341.96 .000 O1,RI,SI,BA
348.80 22.84 341.96 .000 01,RI,SI,BA
348.90 26.87 341.96 .000 O1,RI,SI,BA
349.00 28.99 341.96 .000 O1,RI,SI,BA
349.10 30.45 341.96 .000 O1,RI,SI,BA
349.20 30.87 341.96 .000 RIBA (no Q: Ol,SI)
349.30 31.14 341.96 .000 RI,BA (no Q: 01,SI)
•
349.40 31.40 341.96 .000 RI,BA (no Q: O1,SI)
349.50 31.67 341.96 .000 RI,BA (no Q: O1,SI)
349.60 31.93 341.96 .000 RIBA (no Q: O1,SI)
349.70 32.19 341.96 .000 RIBA (no Q: O1,SI)
349.80 32.45 341.96 .000 RIBA (no Q: O1,SI)
349.90 32.70 341.96 .000 RIBA (no Q: O1,SI)
350.00 32.95 341.96 .000 RIBA (no Q: Ol,SI)
350.10 33.20 341.96 .000 RI,BA (no Q: O1,SI)
350.20 33.69 341.96 .000 RI,BA (no Q: O1,SI)
350.25 33.76 341.96 .000 RI,BA (no Q: O1,SI)
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:13 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.20
is File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARf °t**
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
C:
•
WS Elev, Total Q Notes
-------- -------- -------- Converge
----------
---
------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-------- +/-ft
----- Contributing Structures

345.50
.00
343.21 -
.000 ----------
(no Q: 01 ---------------
,RI,SI,BA)
345.60 .01 343.21 .000 SI,BA (no Q: O1,RI)
345.70 .02 343.21 .000 SI,BA (no Q: Ol,RI)
345.80 .02 343.21 .000 SI,BA (no Q: Ol,RI)
345.90 .02 343.21 .000 SI,BA (no Q: O1,RI)
346.00 .03 343.21 .000 SI,BA (no Q: 01,RI)
346.10 .03 343.21 .000 SI,BA (no Q: O1,RI)
346.20 .03 343.21 .000 SI,BA (no Q: 01,RI)
346.30 .04 343.21 .000 SI,BA (no Q: O1,RI)
346.40 .04 343.21 .000 SI,BA (no n: O1,RI)
346.50 .04 343.21 .000 SI,BA (no Q: O1,RI)
346.60 .04 343.21 .000 SI,BA (no Q: O1,RI)
346.70 .04 343.21 .000 SI,BA (no Q: O1,RI)
346.80 .05 343.21 .000 SI,BA (no Q: Ol,RI)
346.90 .05 343.21 .000 SI,BA (no Q: O1,RI)
347.00 .05 343.21 .000 SI,BA (no Q: O1,RI)
347.10 .15 343.21 .000 01,SI,BA (no Q: RI)
347.20 .45 343.21 .000 01,SI,BA (no Q: RI)
347.30 .93 343.21 .000 01,SI,BA (no Q: RI)
347.40 1.56 343.21 .000 01,SI,BA (no Q: RI)
347.50 2.34 343.21 .000 01,SI,BA (no Q: RI)
347.60 3.26 343.21 .000 01,SI,BA (no Q: RI)
347.70 4.28 343.21 .000 01,SI,BA (no Q: RI)
347.80 5.40 343.21 .000 01,SI,BA (no Q: RI)
347.90 6.58 343.21 .000 01,SI,BA (no Q: RI)
348.00 8.08 343.21 .000 01,SI,BA (no Q: RI)
348.10 8.85 343.21 .000 01,SI,BA (no Q: RI)
348.20 9.55 343.21 .000 01,SI,BA (no Q: RI)
348.30 10.21 343.21 .000 01,SI,BA (no Q: RI)
` ZS^tot Tw ?ih
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:24 AM 101512010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.21
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
•
•
WS Elev, Total Q Notes
-------- -------- -------- Converge ------------- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft Contributing Structures

348.40
10.82 --------
343.68 ----- -
.000 -------------
01,SI,BA (no ------------
Q: RI)
348.50 11.41 343.68 .000 O1,SI,BA (no Q: RI)
348.60 13.85 343.68 .000 O1,RI,SI,BA
348.70 17.86 343.68 .000 O1,RI,SI,BA
348.80 22.84 343.68 .000 O1,RI,SI,BA
348.90 24.97 343.68 .000 O1,RI,SI,BA
349.00 26.63 343.68 .000 O1,RI,SI,BA
349.10 27.48 343.68 .000 O1,RI,SI,BA
349.20 27.73 343.68 .000 RIBA (no Q: O1,SI)
349.30 27.98 343.68 .000 RI,BA (no Q: O1,SI)
349.40 28.23 343.68 .000 RIBA (no Q: O1,SI)
349.50 28.47 343.68 .000 RIBA (no Q: O1,SI)
349.60 28.72 343.68 .000 RI,BA (no Q: O1,SI)
349.70 28.96 343.68 .000 RIBA (no Q: O1,SI)
349.80 29.20 343.68 .000 RIBA (no Q: O1,SI)
349.90 29.44 343.68 .000 RIBA (no Q: O1,SI)
350.00 29.68 343.68 .000 RIBA (no Q: O1,SI)
350.10 29.91 343.68 .000 RI,BA (no Q: O1,SI)
350.20 30.14 343.68 .000 RIBA (no Q: O1,SI)
350.25 30.26 343.68 .000 RIBA (no Q: O1,SI)
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:38 AM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.13
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
**^** COMPOSITE OUTFLOW SUMMARY ****
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
•
•
WS Elev, Total Q Notes
-------- -------- -------- Converge ------- --- --- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft
-------- +/-ft Contrib uting Structures

347.00
.00
343.69 -----
.000 --------
(no Q: ------
RI,OI ------------
,BA)
347.10 .10 343.69 .000 O1,BA (no Q: RI)
347.20 .40 343.69 .000 O1,BA (no Q: RI)
347.30 .87 343.69 .000 O1,BA (no Q: RI)
347.40 1.50 343.69 .000 O1,BA (no Q: RI)
347.50 2.27 343.69 .000 O1,BA (no Q: RI)
347.60 3.21 343.69 .000 O1,BA (no Q: RI)
347.70 4.22 343.69 .000 O1,BA (no Q: RI)
347.80 5.34 343.69 .000 O1,BA (no Q: RI)
3e-7 an 6 s1) 343.69 .000 01,BA (no Q: RI)
348.00 8.02 343.69 .000 O1,BA (no Q: RI)
348.10 8.79 343.69 .000 O1,BA (no Q: RI)
348.20 9.50 343.69 .000 O1,BA (no Q: RI)
348.30 10.14 343.69 .000 O1,BA (no Q: RI)
348.40 10.76 343.69 .000 O1,BA (no Q: RI)
348.50 11.34 343.69 .000 O1,BA (no Q: RI)
348.60 13.79 343.69 .000 RI,O1,BA
348.70 17.79 343.69 .000 RI,O1,B A
348.80 22.79 343.69 .000 RI,O1,B A
348.90 24.95 343.69 .000 RI,O1,B A
349.00 26.61 343.69 .000 RI,O1,BA
349.10 27.45 343.69 .000 RI,O1,BA
349.20 27.71 343.69 .000 RIBA (no Q: O1)
349.30 27.96 343.69 .000 RIBA (no Q: O1)
349.40 28.21 343.69 .000 RIBA (no Q: O1)
349.50 28.45 343.69 .000 RIBA (no Q: O1)
349.60 28.70 343.69 .000 RIBA (no Q: O1)
349.70 28.93 343.69 .000 RI,BA (no Q: O1)
349.80 29.18 343.69 .000 RIBA (no Q: O1)

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 3:58 PM 10/5/2010
Type.... Composite Rating Curve
Name.... Wetland#3
Page 2.14
File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign-100Yr.
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments :
***** COMPOSITE OUTFLOW SUMMARY ***-
CUMULATIVE HGL CONVERGENCE ERROR .000 (+/- ft)
* Max. convergence errors shown may also occur for
flow paths other than the ones listed above.
WS Elev, Total Q Notes
---------------- -------- Converge -------------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------ -------- ----- --------------------------
349.90 29.41 343.69 .000 RI,BA (no Q: 01)
350.00 29.65 343.69 .000 RIBA (no Q: O1)
350.10 29.88 343.69 .000 RIBA (no Q: O1)
350.20 30.11 343.69 .000 RIBA (no Q: O1)
350.25 30.23 343.69 .000 RI,BA (no Q: O1)
•
•
SIN:
Bentley PondPack (10.00.027.00)
3:58 PM
Bentley Systems, Inc.
10/5/2010
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TOWN HALL COMMONS STORMWATER WETLAND #3
PLT-10000 SIZING CALCULATIONS
• => Determination of Water Quality Volume (WQ v)
WQ v = (P) (R v) (A)/12
where,
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total area, A = 4.36 acres
Impervious area = 1.24 acres
Percent impervious cover, I = 28.4 %
Rainfall, P = 1.0 inches
Calculated values:
Rv = 0.31
WQv= 0.11 acre-ft
= 4843 cf.
=> Stormwater Wdland Required Surface Area Calculation
WQ Volume = 4843 cf.
Maximum Ponding Depth = 12 inches
• Surface Area Required at Normal Pool = 4843 SF
=> Associated Pond Depth in Stormwater Wetland
Ks = 5666.2
b = 1.0793
V = 4843
Normal Pool Elevation = 345.50 feet
WQ Elevation = 346.36 feet
=> Determination of 1-Yr Prey-Post Volume Storage Provided by Facility
Input data:
Control Orifice (3 x 12" Dia) Invert = 347.00 feet
Normal Pool Elevation = 345.50 feet
Calculated values:
1-Yr Pre-Dev Runoff Volume (To Wetland #3) = 14,668 cf
1-Yr Post-Dev Runoff Volume (To Wetland #3) = 23,318 cf
1-Yr Pre-Post Volume Difference 8,650 cf
Ks = 5666.2
b = 1.0793
• Storage Provided @ Orifice Invert = 8,777 feet
J. FINCH, PE
10/5/2010

TOWN HALL COMMONS WETLAND
PLT-10000
SIPHON DESIGN
D orifice =
# orifices =
Ks =
b=
Cd siphon =
Normal Pool Elevation =
Orifice Invert =
1" WQ Volume =
WSEL @ 1" Runoff Volume =
#3 - 1" WQ VOLUME
1.25 inch
1
5666
1.0767
0.60
345.50 feet
345.00 feet
4843 cf
346.36 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.455 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.009 sf
Q = 0.0277 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 2.03 days
•
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the 1" storm runoff, with a required time of about 2.03 days.
B.R. FINCH, PE
10/4/2010
0
•
TOWN HALL COMMONS WETLAND #3 -1 YR PRE-POST VOLUME
PLT-10000
SIPHON DESIGN
D orifice = 1.25 inch
# orifices = 1
Ks = 0
b = 5666.2
Cd siphon = 0.60
Normal Pool Elevation = 345.50 feet
Orifice invert = 345.00 feet
1" Pre-Post Volume = 8777 cf
WSEL @ 1-Yr Pre-Post Volume = 347.00 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.667 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.009 sf
Q = 0.0335 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 3.03 days
•
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the difference in 1-Yr Pre-Post Runoff Volume, with a required time of about 3.03 days.
B.R. FINCH, PE
10/5/2010
0
r
PIPE DESIGN SPECIFICATIONS:
1. ASTM C 76-Latest
Class III, N, & V
G- 2. AASNTO M-170-Latest
JOINT DESIGN SPECIFICATIONS:
1. ASTM C443-Latest
' 2. ASTM C-361-Latest
3. Joint Type-114 with "O" Ring
Rubber Gaskets.

.G
X
fE ° JT °
?GS GL TSa ° 4
1 °
L
WT 4
4 a
AST TD °
a4 GW <4
°
01 GAP
ID - P

ID
WT
JT
GD
TD
AS
OI
GW
GS
GL
TS
AST
X
OD Pounds
Per
Foot
Plant
12" B-2 114 3 1/2" 15.260" 14.726" .063" 14.606" .377" 11116" 1" 1" 1/8" 5 314" 19 5116" 123 VB
15" C-3 31/2" 18.759" 18.224" .063" 18.105" .377" 11116" 1" 1" 1/8" 51/2" 23 5116" 191 VB
18" C-3 1/4 3 1/2" 21.787" 21.252" .063" 21.133" .377" 11/16" 1" 1" 118" 6" 261/2' 249 VB
24" C- 3 3/4 3 7/8" 29.138" 28.950" .063" 28.408" .400 7/8" 13/16" 1" 3/32" 6" 351/2" 367 VB
N.T.S
Oldbasfe Precast
N.C. Products
920 Withers Road Raleigh, NC.27603
Phone: [phone] Fox: 919.7721209
8'='0" RINGABS
FILE NAME: 450SPC812RTG2-DET.DWG
ISSUE DATE: JULY, 2008
wwwAdcastleprecastcom
Reinforced "O" RING
Modified Bell & Spigot
Copyright O 2005 owoasapmaec,ine.
TOWN HALL COMMONS Wetland#3 JW Caldwell, PE
PLT-10000 10/5/2010
•
Square Riser/Barrel Anti-Flotation Calculation Sheet
Input Data =>
Inside length of riser =
Inside width of riser =
Wall thickness of riser =
Base thickness of riser =
Base length of riser =
Base width of riser =
Inside height of Riser =
Concrete unit weight =
OD of barrel exiting manhole =
Size of drain pipe (if present) _
Number of detention orifices (if present) _
Size of detention orifice (if present) _
Trash Rack water displacement =
Concrete Present in Riser Structure =>
Total amount of concrete:
•
Adjust for openings:
Base of Riser =
Riser Walls =
Opening for barrel =
Opening for drain pipe -
Opening for detention orifice -
5.00 feet
5.00 feet
6.00 inches
8.00 inches
6.00 feet
6.00 feet
7.50 feet
142.0 PCF
31.50 inches
8.0 inches
3
12.0 inches
61.70 CF
24.000 CF
82.500 CF
2.706 CF
0.175 CF
1.178 CF
Note: NC Products lists unit wt. of
manholo cony eta at 142 PC F.
Total Concrete present, adjusted for openings = 102.441 CF
Weight of concrete present = 14547 lbs
Amount of water displaced by Riser Structure =>
Displacement by concrete = 102.441 CF
Displacement by open air in riser = 187.500 CF
Displacement by trash rack = 61.700 CF
Total water displaced by riser/barrel structure = 351.641 CF
Weight of water displaced = 21942 lbs
Calculate amount of concrete to be added to riser =>
gat ( F It'XWO o Id
Safety factor to use = 1.25 (recommend 1.25 of higher)
Must add = 12881 lbs concrete for buoyancy
Concrete unit weight for use = 142 PCF (note above observation for NCP concrete)
Buoyant weight of this concrete = 79.60 PCF
Buoyant, with safety factor applied = 63.68 PCF
• Therefore, must add = 202.282 CF of concrete
INElbtl'rr or 6D` NWW
ti? ft-00177 N -P SA p-lxe 60-
TOWN HALL COMMONS Wetland#3 JW Caldwell, PE
PLT-10000 tniF-? of ;5010
Standard base described above = 124.000 CF f concrete Ir, RaSc-/-
• Therefore, base design must have = 226.282 CF of concrete
Calculate size of base for riser assembly => -P-/)q7- u r.IGr f OF F-I
at5i= CINa'-a,i& !3"ofew
Length = 9.000 feet 6060
Width = 9.000 feet
Thickness = 34.0 inches
Concrete Present = 229.500 CF OK
Check validity of base as designed =>
Tam wEi(.H-/ a F MC
1(Iavlok'=o C 0V P,( 6A3C-
l 5 vc(-uDEo)
Total Water Displaced = 557.141 CF
Total Concrete Present = 307.941 CF
Total Water Displaced = 34766 lbs
Total Concrete Present = 43728 lbs
Actual safetyfactor = 1.26

OK
Results of design =>
Base length = 9.00 feet '
Base width = 9.00 feet
Base Thickness = 34.00 inches
CY of concrete total in base = 8.50 CY
Concrete unit weight in added base >= 142 PCF
r ?
?J
TOWN HALL COMMONS WETLAND #2 & 3 B.R. FINCH, PE
PLT-10000 10/5/2010
•
Velocity Dissipator
NRCD Land Quality Section
Pipe Design
Entering the following values will provide you with the expected outlet velocity and depth of flow in a pipe,
assuming the Manning's roughness number is constant over the entire length of the pipe.
Flow Qlo (cfs) = 18.44 Qio !e/}5EO 46x1 it hea OraFAt,(, l P& M"
Slope S (%) = 1.89?,? ?[oNM7I?nf)
Pipe Diameter Do (in) = 30
Manning's `n' = 0.013
Flow Depth (ft) = 0.98
Outlet Velocity (fps) = 10.283
NRCD Land Quality Section
NYDOT Dissipator Design Results
U
Pipe Diameter (ft) = 2.50
Outlet Velocity (fps) = 10.28
Apron Length (ft) = 1 5.00
d50 Stone Thickness
(inches) Class (inches)
3 A 9
-? 6 B 22
13 Bor1 22
23 2 27
Width = La + Do
Width = 15 + 2.5
Width (ft) = 17.5 Use 18-ft
Use NCDOT Class `B' Rip Rap
d50 = 8"
15'L x 18'W x 22"Thick
0
•

FINAL STORMWA TER WETLAND #4 DESIGN
CALCULATIONS
0
0
TOWN HALL COMMONS
PLT-10000
•
TOWN HALL COMMONS STORMWATER WETLAND #4
PLT-10000
Stage-Storage Function
Project Name: Town Hall Commons
Designer: J. Finch, PE
Job Number: PLT-10000
Date: 10/5/2010
•
J. FINCH, PE
10/5/2010
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Volume
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (CF)
350.00 0.0 2,631
351.00 1.0 3,472 3051 3051 3051 1.01
352.00 2.0 4,008 3740 3740 6791 1.97
353.00 3.0 4,565 4287 4287 11078 2.98
354.00 4.0 5.144 4854 4854 15932 4.05
Storage vs. Stage
18000
16000 1 189
y = 3023.7x
14000 R2 = 0.9996
uV0000
60000--
.28000
N
6000
4000
2000
0
0.0 0.5 1.0 1.5 Stage (W4 3.0 3.5 4.0 4.5
Ks = 3023.7
b = 1.189
0
TOWN HALL COMMONS STORMWATER WETLAND #4 J. FINCH, PE
PLT-10000 10/5/2010
• _> Stage - Storage Function
Ks = 3023.7
b = 1.189
•
Zo = 350.00
Elevation
[feet] Storage Elevation
[cf] [acre-feet] [feet] 100-Year
[cf] [acre-feet]
350.00 0 0.000 0 - -
350.20 446 0.010 0
T - -
350.40 1017 0.023 350.40 - -
350.60 1647 0.038 0 - -
350.80 2319 0.053 350.80 - -
351.00 3024 0.069 351.00 - -
351.20 3756 0.086 351.20 - -
351.40 4511 0.104 351.40 - -
351.60 5287 0.121 351.60 0 0.000
351.80 6082 0.140 351.80 795 0.018
352.00 6894 0.158 352.00 1607 0.037
352.20 7721 0.177 352.20 2434 0.056
352.40 8563 0.197 352.40 3275 0.075
352.60 9418 0.216 352.60 4130 0.095
352.80 10285 0.236 352.80 4998 0.115
353.00 11164 0.256 353.00 5877 0.135
353.20 12055 0.277 353.20 6768 0.155
353.40 12956 0.297 353.40 7669 0.176
353.60 13867 0.318 353.60 8580 0.197
353.80 14788 0.339 353.80 9500 0.218
354.00 15718 0.361 354.00 10430 0.239
0
Type.... Vol: Elev-Volume
Name.... WETLAND #4
Page 3.06
is File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
USER DEFINED VOLUME RATING TABLE
Elevation Volume
(ft)
----------- (cu.ft)
----------
350.00 0
350.20 446
350.40 1017
350.60 1647
350.80 2319
351.00 3024
351.20 3756
351.40 4511
351.60 5287
351.80 6082
352.00 6894
352.20 7721
352.40 8563
352.60 9418
352.80 10285
353.00 11164
353.20 12055
353.40 12956
353.60 13867
353.80 14788
354.00 15718
•
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 11:19 AM 10/7/2010
Type.... Outlet Input Data
Name.... Wetland#4
Page 2.01
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 350.00 ft
Increment = .10 ft
Max. Elev.= 354.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure
----------------- No.
---- Outfall
----
-- E1, ft
------ E2, ft
---------
Orifice-Circular OR -
---> BA ---
351.600 354.000
Inlet Box RI ---> BA 352.500 354.000
Orifice-Circular SI ---> BA 350.000 354.000
Culvert-Circular BA ---> TW 348.000 354.000
• TW SETUP, DS Channel
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
Type.... Outlet Input Data
Name.... Wetland#4
Page 2.02
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = OR
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 3
Invert Elev. = 351.60 ft
Diameter = .3333 ft
Orifice Coeff. _ .600
Structure ID = RI
Structure Type
------------------ = Inlet Box
-

# of Openings -----------------
= 1
Invert Elev. = 352.50 ft
Orifice Area = 16.0000 sq.ft
Orifice Coeff. _ .600
• Weir Length 16.00 ft
Weir Coeff. -
3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Structure ID = SI
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 350.00 ft
Diameter = .0625 ft
Orifice Coeff. _ .600
is
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
Type.... Outlet Input Data
Name.... Wetland#4
Page 2.03
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = BA
Structure Type
------------------ = Culvert-Circular
--

No. Barrels ---------
= 1 -------
Barrel Diameter = 1.2500 ft
Upstream Invert = 348.00 ft
Dnstream Invert = 347.75 ft
Horiz. Length = 23.00 ft
Barrel Length = 23.00 ft
Barrel Slope = .01087 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000
Kb = .023225
Kr = .5000
HW Convergence = .001
•
•
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) = 1.155
T2 ratio (HW/D) = 1.301
Slope Factor = -.500
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/- ft
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 349.44 ft ---> Flow = 4.80 cfs
At T2 Elev = 349.63 ft ---> Flow = 5.49 cfs
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
Type.... Outlet Input Data
Name.... Wetland#4
Page 2.04
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 40
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
I
J
F- -I
L J
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
Type.... Composite Rating Curve
Name.... Wetland#4
Page 2.17
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge ---------- --- ------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
-------- Contributing Structures

350.00
.00
Free -----
Outfall -----------
(no Q: OR ---------------
,RI,SI,BA)
350.10 .00 Free Outfall SI,BA (no Q: OR,RI)
350.20 .00 Free Outfall SI,BA (no Q: OR,RI)
350.30 .01 Free Outfall SI,BA (no Q: OR,RI)
350.40 .01 Free Outfall SI,BA (no Q: OR,RI)
350.50 .01 Free Outfall SI,BA (no Q: OR,RI)
350.60 .01 Free Outfall SI,BA (no Q: OR,RI)
350.70 .01 Free Outfall SI,BA (no Q: OR,RI)
350.80 .01 Free Outfall SI,BA (no Q: OR,RI)
350.90 .01 Free Outfall SI,BA (no Q: OR,RI)
351.00 .01 Free Outfall SI,BA (no Q: OR,RI)
351.10 .01 Free Outfall SI,BA (no Q: OR,RI)
351.20 .02 Free Outfall SI,BA (no Q: OR,RI)
351.30 .02 Free Outfall SI,BA (no Q: OR,RI)
• 351.40 .02 Free Outfall SI,BA (no Q: OR,RI)
351.50 .02 Free Outfall SI,BA (no Q: OR,RI)
351.60 .02 Free Outfall SI,BA (no Q: OR,RI)
351.70 .07 Free Outfall OR,SI,BA (no Q: RI)
351.80 .22 Free Outfall OR,SI,BA (no Q: RI)
351.90 .44 Free Outfall OR,SI,BA (no Q: RI)
352.00 .63 Free Outfall OR,SI,BA (no Q: RI)
352.10 .75 Free Outfall OR,SI,BA (no Q: RI)
352.20 .85 Free Outfall OR,SI,BA (no Q: RI)
352.30 .94 Free Outfall OR,SI,BA (no Q: RI)
352.40 1.03 Free Outfall OR,SI,BA (no Q: RI)
352.50 1.10 Free Outfall OR,SI,BA (no Q: RI)
352.60 2.69 Free Outfall OR,RI,SI,BA
352.70 5.54 Free Outfall OR,RI,SI,BA
352.80 9.19 Free Outfall OR,RI,SI,BA
352.90 12.36 Free Outfall OR,RI,SI,BA
353.00 12.56 Free Outfall RI,BA (no Q: OR,SI)
353.10 12.71 Free Outfall OR,RI,SI,BA
353.20 12.86 Free Outfall RI,BA (no Q: OR,SI)
353.30 13.01 Free Outfall RI,BA (no Q: OR,SI)
•
SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
Type.... Composite Rating Curve
Name.... Wetland#4
Page 2.18
• File.... X:\Projects\PLT\PLT-10000\Storm\Site Plan Approval\Design Files\SWMFDesign.ppw
Title... Project Date: 5/12/2010
Project Engineer: J. Finch, PE
Project Title: Town Hall Commons
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ------ -- Converge
------
----
---
------------
Elev. Q TW El ev Error
ft
-------- cfs
------- ft
------ +/-ft
-- Contributing Structures

353.40
13.15
Free -----
Outfall -------
RIBA ----
(no ---
Q: ------------
OR,SI)
353.50 13.29 Free Outfall RIBA (no Q: OR,SI)
353.60 13.43 Free Outfall RIBA (no Q: OR,SI)
353.70 13.57 Free Outfall RIBA (no Q: OR,SI)
353.80 13.71 Free Outfall RIBA (no Q: OR,SI)
353.90 13.85 Free Outfall RIBA (no Q: OR,SI)
354.00 13.99 Free Outfall RIBA (no Q: OR,SI)
•

SIN: Bentley Systems, Inc.
Bentley PondPack (10.00.027.00) 1:30 PM 10/15/2010
TOWN HALL COMMONS STORMWATER WETLAND #4
PLT-10000 SIZING CALCULATIONS
• => Determination of Water Quality Volume (WQ v)
WQ v = (P) (R v)(A)/12
where,
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(I) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Total area, A = 1.30 acres
Impervious area = 0.68 acres
Percent impervious cover, I = 52.4 %
Rainfall, P = 1.0 inches
Calculated values:
Rv = 0.52
WQv= 0.06 acre-ft
= 2462 cf.
Stormwater Wetland Required Surface Area Calculation
WQ Volume = 2462 cf.
Maximum Ponding Depth = 12 inches
Surface Area Required at Normal Pool= 2462 SF
_> Associated Pond Depth in Stormwater Wetland
Ks = 3023.7
b = 1.189
V = 2462
Normal Pool Elevation = 350.00 feet
WQ Elevation = 350.84 feet
=> Determination of I-Yr Pre-Post Volume Storage, Provided by Facility
Input data:
Control Orifice (3 x 4" Dia) Invert= 351.60 feet
Normal Pool Elevation= 350.00 feet
Calculated values:
1-Yr Pre-Dev Runoff Volume (To Wetland #4) = 2,024 cf
1-Yr Post-Dev Runoff Volume (To Wetland 44) = 7,148 cf
1-Yr Pre-Post Volume Difference = 5,124 cf
Ks = 3023.7
• b - 1.189
Storage rrovided @ Orifice Invert 5,2x7 feet
J. FINCH, PE
10/5/2010
•
TOWN HALL COMMONS
PLT-10000
SIPHON DESIGN
WETLAND #4 -1" WQ VOLUME
D orifice = 0.75 inch
# orifices = 1
Ks = 3023.7
b = 1.189
Cd siphon = 0.60
Normal Pool Elevation = 350.00 feet
Orifice Invert = 349.50 feet
1" WQ Volume = 2462 cf
WSEL @ 1" Runoff Volume = 350.84 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.447 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.003 sf
Q = 0.0099 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 2.89 days
•
Conclusion : Use 1- 0.75" Diameter PVC inverted siphon to drawdown the accumulated volume
from the 1" storm runoff, with a required time of about 2.89 days.
B.R. FINCH, PE
10/4/2010
•
r
?J
TOWN HALL COMMONS
PLT-10000
SIPHON DESIGN
WETLAND #4 -1 YR PRE-POST VOLUME B.R. FINCH, PE
10/5/2010
D orifice = 0.75 inch
# orifices = 1
Ks = 3023.7
b = 1.189
Cd siphon = 0.60
Normal Pool Elevation = 350.00 feet
Orifice Invert = 349.50 feet
1" WQ Volume = 5287 cf
WSEL @ 1" Runoff Volume = 351.60 feet
Using the average head over the orifice (assuming average head is
one-third the total depth), the result would be:
Average driving head on orifice = 0.700 feet
Orifice composite loss coefficient = 0.600
Cross-sectional area of 1.25" orifice = 0.003 sf
Q = 0.0124 cfs
Drawdown Time = Volume / Flowrate / 86400 (sec/day)
Drawdown Time = 4.95 days
•
Conclusion : Use 1-1.25" Diameter PVC inverted siphon to drawdown the accumulated volume
from the difference in 1-Yr Pre-Post Runoff Volume, with a required time of about 4.95 days.
.7

d
r'
i?
PIPE DESIGN SPECIFICATIONS:
1. ASTM C 764Latest
Class III, IV, & V
2. AASHTO M-1704Latest
JOINT DESIGN SPECIFICATIONS: E
1. ASTM C443-1-atest
2. ASTM C-361-1-atest
3. Joint Type-114 with "O" Ring
Rubber Gaskets.

X
i
t
t
JT d a d OD d a
GS GL I TSB a !
d
? Od
d a
ad
a ?4
a
? a
a a
? d G
a ?
d ASd AST TD GD
a d
0
a
a GW p d
da d
01 I y6..
ID ~{ GAP

ID
WT
JT
GD
TD
AS
OI
GW
GS
GL
TS
AST
X
OD Pounds
Per
Foot
Plant
12" B-2 114 31/2" 15.260" 14.725" .063" 14.606" .377" 11/16" 1" 1" 1/8" 5 3/4" 19 5/16" 123 VB
15" C-3 3 1/2" 18.759" 18.224" .063" 18.105" .377" 11/16" 1" 1" 1/8" 51/2" 23 5/16" 191 VB
18" C31/4 31/2" 21.787" 21.262" .063" 21.133" .377" 11/16" 1" 1" 1/8" 6" 26112' 249 VB
24" C- 3 3/4 3 7/8" 29.138" 28.950" .063" 28.408" .400 7/8" 13/16" 1" 3/32" 6" 351/2" 367 VB
c
st
10 Oldcastle Pr
e
a
N.C. Products
920 Withers Road Raleigh, NC.27603
Phone: [phone] Fox: 919.772.1209
N.T.S.
8'='0" RING-RBS
FILE NAME: 450SPC812RTG2_DET.DWG
? ISSUE DATE: JULY, 2008
unuu nWn'QHnn?nw?e4 wwm
Reinforced "O" RING
Modified Bell & Spigot
© 2005 owoas,d:arast,lre
r
U
TOWN HALL COMMONS
PLT-10000
Total amount of concrete:
Base of Riser = 16.667 CF
Riser Walls = 22.500 CF
•
Opening for barrel = 1.203 CF
Opening for drain pipe = 0.175 CF
Square Riser/Barrel Anti-Flotation Calculation Sheet
Input Data =>
Inside length of riser = 4.00 feet
Inside width of riser = 4.00 feet
Wall thickness of riser = 6.00 inches
Base thickness of riser = 8.00 inches
Base length of riser = 5.00 feet
Base width of riser = 5.00 feet
Inside height of Riser = 2.50 feet
Concrete unit weight = 142.0 PCF
OD of barrel exiting manhole = 21.00 inches
Size of drain pipe (if present) = 8.0 inches
Trash Rack water displacement = 38.00 CF
Concrete Present in Riser Structure =>
Adjust for openings:
Total Concrete present, adjusted for openings =
Weight of concrete present =
Amount of water displaced by Riser Structure =>
Displacement by concrete = 37.789 CF
Displacement by open air in riser = 40.000 CF
Displacement by trash rack = 38.000 CF
JW Caldwell, PE
10/5/2010
Note: NC Noducts lists unit wt. 4
manholo con zcta at 142 PCF.
37.789 CF
5366 lbs
Total water displaced by riser/barrel structure = 115.789 CF
Weight of water displaced = 7225 lbs
•
Calculate amount of concrete to be added to riser =>
Safety factor to use = 1.25 (recommend 1.25 (m lu ghco
Must add = 3665 lbs concrete for buoyancy
Wetland #4
ow ft c l Nu-oil
)u 96FA
Concrete unit weight for use =
Buoyant weight of this concrete =
Buoyant, with safety factor applied =
142 PCF (note above observation for NCP concrete)
79.60 PCF
63 6R PCF
Therefore, must add =
Standard based described above =
Therefore, base design must have =
VOCKIttT OF coN , L'CC
E57.561 CF of concrete (N Aw ?^l -P ® (1 ve45E2
6t1sr=
J 16.667 C of concrete
tn.Gt (I °1'T a ? ('rnct? I ?ti
15C of concrete pw- 6A:5G-
Itia'aw& rd"OP-lurkA(. 6l50
TOWN HALL COMMONS Wetland #4 JW Caldwell, PE
PLT-10000 10/5/2010
• Calculate size of base for riser assembly =>
Length =
Width =
Thickness =
Concrete Present =
Check validity of base as designed =>
8.000 feet
8.000 feet
14.0 inches
74.667 CF
Total Water Displaced =
Total Concrete Present =
Total Water Displaced =
Total Concrete Present =
Actual safety factor
Results of design =>
•
OK
173.789 CF
95.789 CF
10844 lbs
13602 lbs
1.25
6 0( 80134=
OK
Base length = 8.00 feet
Base width = 8.00 feet
Base Thickness = 14.00 inches
CY of concrete total in base = 2.77 CY
Concrete unit weight in added base >= 142 PC"F
0
L J
TOWN HALL COMMONS
PLT-10000
WETLAND #4
Velocity Dissipator
NRCD Land Quality Section
Pipe Design
B.R. F[NCH, PE
12/3/2010
Entering the following values will provide you with the expected outlet velocity and depth of flow in a pipe,
assuming the Manning's roughness number is constant over the entire length of the pipe.
Flow Qto (cfs) = 254---- AMASO A Ir - AM-4 a"1n/G
Slope S (%) = 1.14 S`M
Pipe Diameter Do (in) = 36 ?'f?s? P(r? fGrlt)
Manning's 'n' = 0.013
Flow Depth (ft) = 1.23
Outlet Velocity (fps) = 9.193
•
NRCD Land Quality Section
NFDOT Dissipator Design Results
Pipe Diameter (ft) = 3.00
Outlet Velocity (fps) = 9.19
Apron Length (ft) = 18.00
d50 Stone Thickness
(inches) Class (inches)
3 A 9
-+ 6 B 22
13 B or 1 22
23 2 27
Width = La + Do
Width = 18 + 3
Width (ft) = 21
Use NCDOT Class `B' Rip Rap
d50 = 8"
18'L x 2VW x 22"Thick

•
•
ANALYSIS OF EXISTING OFFSITE TWIN
LADES WET POND BMP
0
0
TOWN BALL COMMONS
PLT-10000
•
•
Project Name: Twin Lakes - Parcel B
City/State: Cary, NC
Project #i: 204177.71
Date: 6-Apr-06
Table 1. 1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
Removal Fffirienrv in fhp Phvdmnnf
% Impervious
Cover Permanent Pool Depth (feet)
3.0 4.0 5.0 6.0 7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 651 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
- - .•.? .v uvvaic ucx ivianegement rracuces, pg- 5, April 1999
STORMWATER BMP 5 PARCEL B - WET POND (25% TN Removal)

Land Use Area
(ac) % IA Imp. Area
(ac)
Impervious 1.47 100 1.5

Lots
6.65
40 _
2.7
Open Space 0.85 0 0.0
Mite 2.11 60 1.3
Totals 11.08 5.4
Total % Impervious Surface Area = 48.7 %
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio = 2.02 % From Table 1.1
BMP5
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/] 00
SA acres
9749 sq. ft_ ------_---- /ItINIP'1"M ONO 5A gfaviK$7
L° L Pool
Normal pool elevation = 356.0 feet
Surface area provided = 0.360acres
15679 sq. ft. ---- y C E516P 5A P9PJ10EP
1-Inch Runoff Volume Calculation ..,,,,, ` PRWt!)W = 13, t{-* Si
Using the runoff volume calculations in the "Simple Method" as described by Schueler (i 987) ?j'??bp??
Rv = 0.05 + 0.009(1) where, Rv = Runoff coefficient, in./in-
I = Percent impervious
Rv = 0.49 in./in-
0

Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.4 re ft
640 cu. ft. --
Water quality pool elevation =
Storage volume provided =
Twin Lakes BMP Sizing.xls
® M ItilaiL I wa vowmE 5Toj4iii
jeRAA #*P
357.20 feet
0.461 acre-ft
0081 cu. E9r Vj Wa %40L,. ,WC- 5WAe r
egwww
ASGOU t>wOt. AVM E -ROVA" I 194Q-: Aa
?l,001 ?
TOWN HALL COMMONS EXISTING OFFSITE TWIN LAKES SW WETLAND
PLT-10000
• Stage-Storage Function
Project Name: Town Hall Commons
Designer: J. Finch, PE
Job Number: PLT-10000
Date: 10/6/2010
J. FINCH, PE
10/6/2010
"VIC-r PORMP
?baL -;v9 Acf-
AO&
MIN N)Pnf
Pm?c. SAf 9f0j'A
•
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Volume
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) 1SF) (SF) (CF) (CF) (CF)
356.06 0.0 13,476

357.00
0.9
5.
14647 _
13768
13768
0.94
358.00 1.9 17,248 16533 16533 30301 1.93
359.00 2.9 18.714 17981 17981 48282 2.94
359.66 3.6 19.439 19077 12591 60873 3.62
Storage vs. Stage
70000
60000 y = 14683x' joss
50000 RZ = 0.9999
LL
V 40000
m
rn
c 30000
20000
10000
0
0.0 0.5 1.0 1.5 Stag; Weet) 2.5 3.0 3.5 4.0
Ks = 14683
b = 1.1055
is
TOWN HALL COMMONS EXISTING OFFSITE TWIN LAKES SW WETLAND J. FINCH, PE
PLT-10000 10/11/2010
•
•
Stage - Storage Function
Ks = 14683
b= 1.1055
Zo = 356.06
Elevation Storage
[feet] [cf]
.._ [acre-feet]
, FO? C
?$Ul ?f? (TiF1L' 3 ?O
356.06 O 0.000
356.26 - . 2478 0.057 f J]a- ceE Ead ' 3V• 4
356.46 5332 0.
122
356.66 -
8.348 -_ 1.
1
_. 0.192 --, lglll L? in(611 Zlt 8Dy
356.86 11473 0.263
? R 1 D = G10C
l'?jN ?6t
357.06 14683 0.337 5(
?
357.26 17962 0.412
357.46 21299 0.489
357.49 21804 0.501
357.56 22987 0.528
357.76 26398 0.606
357.96 29852 0.685
358.16 33345 0.765
358.36 36873 0.846
358.56 40433 0.928
358.76 44024 1.011
358.96 47643 1.094
359.16 51288 1.177
359.36 54958 1.262
359.56 58652 1.346
359.66 60507 1.389
r
.7
FINAL TN EXPORT CALCULATIONS
is
0
TOWN HALL COMMONS
PLT-10000
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