20080781 Ver 1_Stormwater Info_20080506

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SURFACE WATER
MANAGEMENT REPORT
GASTON MALL
REDEVELOPMENT PROJECT
NW CORNER OF COX ROAD
AND FRANKLIN BLVD
GASTONIA, NC
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PP-GASTON MALL, LLC
January 2008
Woolpert Project No. 064961
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TABLE OF CONTENTS
Page(s)
Abstract ................................................................................. 1
Existing Conditions ................ 1
............................................... . . ..
Proposed Conditions .................................................................. 1
Criteria .................................................................................. 6
Methodology ................................................................
Computations ........................................................................... 9
Addenda A, Dated 2/29/08
Exhibits:
A - Location Map ............................................................ 2
B - Existing Conditions Map ............................................... 3
C - Soils Map ................................................................. 4
D - Proposed Overall Site Plan ............................................. 5
E - Paving and Grading Plan .............. ....... 17-20
F - Drainage Area Map ...................................................... 21
G - Drainage Sub-Basin Map ................................................ 22
Tables:
1 - Summary Tabulation ..................................................... 13
2 - Underground Detention, Stage vs. Storage ........................... 14
3 - Storm Filter Sizing ............................ : .... 15
..................... .
Appendices:
A - Hydraulic Calculations
B - Runoff and Detention Calculations - Out Parcel A
C - Runoff and Detention Calculations - Out Parcel B
D - Runoff and Detention Calculations - Area C
E - Runoff and Detention Calculations - Area D
F - Runoff and Detention Calculations - Area E
G - Runoff and Detention Calculations - Area F
H - Runoff and Detention Calculations - Area G
I - Runoff and Detention Calculations - Area H
3 - Routing Calculations - Area H
K - Bio-Retention Area Calculations
L - Storm Filter Sizing Calculations
M - Storm Filter Plan and Detail
N - Storm Filter Operation and Maintenance
Attachments
ABSTRACT
Pearson Properties plans to redevelop the existing Gaston Mall located at the southwest corner of
Cox Road and Interstate 85 in the City of Gastonia, North Carolina. A location map is included
as Exhibit A on page 2 for reference. The plan for redevelopment includes a mix of demolition,
re-construction, and refurbishment to portions of the existing mall and new construction on the
previously vacant portion of the property. Construction is anticipated to be sequenced in order to
assist in maintaining existing business operations as required during the renovation.
The project boasts some unique requirements, such as a FEMA Letter of Map Revision, a large
culvert or bridge crossing over Duhart's creek which runs thru the site, a significant length of
retaining wail, and a private roadway thru the property that connects Cox Road and Franklin
Boulevard.
EXISTING CONDITIONS
The site consists of roughly 44 acres. A little less than half of the property is occupied by the
existing mall, which was built sometime around 1970. For reference, the Existing Conditions
Plan is included as Exhibit Bon page 3 of this report.
Duhart's Creek and Tributary D-8 flow through the site. These two features are the focal point of
the 100 year flood plain which encompasses a fair portion of the property including part of the
existing parking lot.
A fifteen foot (15') diameter culvert conveys Duhart's creek from the west side of the mall to the
east side of Cox Road. A series of drainage inlets and pipe convey runoff from the-east and south
side of the mall directly to said culvert. Conveyance is controlled by the inlet and pipe size only.
The parking areas lying along the northwest portion of the site convey thru either a combination
of pipes and inlets or overland flow into Tributary D-8.
The westerly portion of the site is undeveloped at this time. A significant grade change exists
between the extents of the property to the southwest at the frontage along both East Club Drive
and Franklin Road and the existing mall.
PROPOSED CONDITIONS
An overall site plan is included as Exhibit D on page 5
The existing restaurant in the northeast portion of the site will be razed and replaced by a new
strip mall. A retaining wall is planned for along Cox Road in order to blend this portion of the
development into the overall plan. A small detention area shall be constructed just north of this
building to assist in reducing potential surcharge of the existing inlets north of Harris Teeter.
Woolpert,_Inc Gaston Mall Redevelopment Project 1
January 2008 PP Gaston Mall, LC
Exhibit A - Location Map
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The center portion of the existing mall will be razed to allow construction of the new thru
roadway. Some of the retail shops on the south side of the existing Harris Teeter will be re-
developed. The remaining portions of the existing mall will benefit from refurbishment.
The northwesterly portion of the site will be developed. The area is identified as Retail 1 on the
overall site plan. Underground detention will be incorporated into this phase of development to
meet water quality and quantity criterion. Underground detention was chosen due to practicality
and proximity to the point of discharge.
A bi.o-retention area will be added to the rear of Retail 1 in order to provide stormwater storage
and assist in meeting the water quality requirements.
Two out-parcels will be graded for future development. Each of these parcels shall require water
management facilities for both stormwater quality and quantity at time of development.
A proposed roadway will connect Cox Road and Franklin Boulevard. Said roadway will provide
access to the parcels within the development. The roadway design will include a grade change of
approximately fifty vertical feet between the existing mall and the connection to Franklin Road
Woolpert, Inc Gaston Mall Redevelopment
January 2008 PP Gaston Mall, LLC
CRITERIA
Several review entities have either jurisdiction over the development of this project. These
include the City of Gastonia, Gaston County Natural Resources Department and the Army Corps
of Engineers. For ease of reference, excerpts from the criterion are outlined below.
A. In accordance with the City requirements, the criteria for the stormwater management
system is based upon the pre-development versus the post-development rate of discharge from the
site for both the two and ten year, 24 hour storm events. The City codes states in Section 17-
140(c):
Both the two-year and ten year frequency storms shall be used in determining the amount of
stormwater runoff generated. Control structure release rates shall approximate peak runoff rates
for the two-year and ten-year storms, with emergency overflow capable of handling the 50 year
discharge....Impoundmentfacilities located within automobile parking areas shall not exceed a
maximum water depth of six inches.... Storage volume shall be adequate to attenuate the post-
development peak discharge rates to pre-developed discharge rates for the two-year and ten-year
storms. Routing calculations must be used to demonstrate that the storage volume is adequate.
For detention basins, all detention volume shall be drained within 72 hours....
Because the site is a redevelopment project, the term "predevelopment" can be interpreted as
either the existing condition or the property prior to any development. For that reason, the City
code adds clarity to the issue in Section 17-140(d):
Full storm-water detention requirements (the same as if. the site was undeveloped) shall apply to
redevelopment of sites, conversions and expansions meeting any of the following thresholds:
(1) Redevelopment of a site involving the razing of 50 percent or more of the total first floor square
footage of all buildings on the site (as used herein, the term "razing" shall also include the removal of
exterior building walls to the floor level); or
(2) Reconstruction of 50 percent or more of the total square footage of all impervious surface areas,
excluding buildings, on the site; or
(4) Any increase of 50 percent or more in the amount of impervious surface area on the site existing
upon February 15, 2000, or any incremental increase which results in a total cumulative increase in
50 percent or more in the amount of impervious surface on the site existing upon February 15, 2000.
For areas of the site undergoing redevelopment, a coefficient of runoff of 0.25 shall be used
Expansions or redevelopment of sites which are less than the above thresholds shall only be required
to install stormwater detention for the incremental increase in impervious surface area over the
amount of impervious surface existing immediately prior to such expansion or redevelopment.
Based upon application of the code and the level of anticipated development and redevelopment,
the proposed improvements do not exceed any of the aforementioned thresholds.
The County states in Section 13.b.6 and 7 of the stormwater ordinance that "Stormwater detention
shall be provided to insure that the rate of discharge for the I year, 24 hour storm does not exceed the
predevelopment rate of discharge. In order to demonstrate this, inflow/outflow calculations shall also be
submitted for any stormwater detention ponds" and "All Stormwater systems shall be designed and built to
route at a minimum the 25 year 24 hour storm safely" respectively. The requirement to not exceed the
rate of discharge for the 1 year, 1 day storm event shall be excluded from this analysis as the City
criteria is more stringent. The routing calculation for the 25 year, 1 day storm event shall be
included because the potential suitor of the Retail 1 site requires that the inlets not be surcharged
more than 6" for the particular event.
B. The City requires that the hydraulic gradient does not exceed the rim elevation for the 10
year storm event. This analysis of the conveyance system is accomplished using Hydroflow
Storm Sewers (2005) for the hydraulic calculations. For this project, modifications to the existing
Woolpert, Inc Gaston Mall Redevelopment Project
January 2008 PP Gaston Mall,. LLC
drainage system and patterns are expected. Data for the existing system will be compiled from
combining survey data, available plan sets for the existing mall, and field observation.
C. The City and County require that the discharge water meet the minimum requirements for
stormwater quality. The County states in Section 13.b.1 and 2 of the stormwater ordinance that
"The measures shall control and treat at a minimum the stormwater runofffrom the first inch of rainfall
volume leaving the project site. Runoff volume drawdown time shall be a minimum of 48 hours, but not
more than 120 hours. " and "All structural stormwater treatment systems used to meet the requirements of
this ordinance shall be designed to have a minimum of 85% average annual removal for Total Suspended
Solids (TSS) " respectively.
The water quality calculation shall be based upon the new and re-constructed portions of the site.
These areas are further defined in the methodology and calculation section of this report.
An underground detention system and bio-retention area shall be employed to meet both the
stormwater management and water quality needs of the site. With the assistance of Contech
Stormwater Solutions, a vault utilizing Contech's Stormfilter units shall be implemented to meet
the requirements for stormwater quality for the discharge from the underground detention system.
D. Lastly, an analysis will be provided to ensure that the volume of discharge does not
exceed that of the existing condition. Although not part of the City nor County code, it is duly
noted that a number of residents participated in public hearings at both the Planning and Zoning
Commission and City Council. According to the oral testimony, residents living along Duhart 's
Creek downstream of this property have a history of flooding. Generally speaking, the residents
spoke in opposition citing that the level of flooding will be heightened. While rising water may
be limited to the rear yards and the like, exercise of fiduciary judgment mandates that the design
consider a potential increase of runoff volume generated by the improvements to the property.
METHODOLOGY
The computations methods employed by this analysis are three fold. They are as follows:
1. Analyze and size the conveyance system for adequate drainage.
2. Analyze and design the stormwater storage requirement and discharge structure to
regulate the rate of discharge.
3. Integrate and design a system(s) adequate to meet the stormwater quality requirements.
Because this is a redevelopment project, idiosyncrasies and inherent challenges are to be
anticipated. The following is a catalog of the necessary steps in the three analysis listed above.
ANALYZE AND DESIGN THE CONVEYANCE SYSTEM
As with most drainage systems, runoff is conveyed using drainage inlets and piped connections.
This portion of the analysis focuses on the sizing of the conveyance system.
A. Determine the existing drainage patterns Included in the attachments are the
construction plans for the mall thru the years and the current survey of the property. Using
these pieces of information coupled, with field observation, the existing drainage system can
be created.
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January 2008 PP Gaston Mall, LLC
B. Identify deficiencies in the existing drainage system. The existing drainage system is tied
directly into the 15 foot underground culvert that conveys Duhart's Creek thru developed
portion of the site. Changes due to site modifications over the years and comparison to
current criteria will likely bring to light deficiencies in the existing system.
C. Design the proposed grading and drainage system. After identifying potential
deficiencies, the proposed design must properly integrate portions of the existing drainage
system to remain into the proposed improvements.
D. Analyze the conveyance network. Analyze the drainage system(s) using Hydroflow
Storm Sewers (2005) for hydraulic calculations and adjust the pipe sizes if necessary to meet
the criteria.
STORMWATER STORAGE AND DISCHARGE STRUCTURE DESIGN
The second portion of the analysis is the sizing of the detention basin. Because the discharge
structure is closely tied to the water quality calculation, the design of this facet will be deferred to
the final part of the report.
A. Identify the drainage sub-basins within the project The project is broken into several
distinctly segregated sub-basins.
B. Categorize how the drainage sub-basins within the project should be analyzed.
C. Compute the detention required and the allowable rates of discharge. The required
volume and allowable discharge rates is computed using the existing conditions versus the
proposed conditions for the 2, 10 and 25 year storm events. The computation is performed
using Pondpack by Haestaed Methods. The analysis is based on the rational method and
comparing the existing against post developed flow rates and runoff volumes. The design of
the discharge structure will be deferred until the water quality volume and storage
requirement has been analyzed.
D. Design the underground detention system. The design will done based upon the required
amount. The layout and design effort will be assisted by Contech Stormwater Solutions.
STORMWATER QUALITY DESIGN
The final aspect of the stormwater management system is water quality volume. The rate of
discharge from the water quality system can then be used in the design of a discharge structure.
A. Categorize how the drainage sub-basins within the project should be analyzed. Special
consideration is required due to the nature of this project. For example, new construction or
re-development shall meet the requirements. Existing areas may be excluded. Future
development of parcels will require their own water quality.
B. Design a system(s) to meet the water quality requirement. The requirement will be
satisfied through a combination of bio-retention and stormfilter units by Contech Stormwater
Solutions. The bio-retention will be located to the west of Retail 1. The stormfilter unit will
be located within the parking area of Retail 1.
Woolpert, Inc Gaston Mall Redevelopment Project
January 2008 PP Gaston Mall, LLC
C. Design the by-pass system for the allowable rate of discharge. This design of the
structure is included at this juncture as it dependent upon and integral to the design of the
stormfilter units.
COMPUTATIONS
1. ANALYZE AND DESIGN THE CONVEYANCE SYSTEM
A. Determine the existing drainage patterns
The Existing Conditions Plan is included as Exhibit B on page 3. Runoff from the existing
site discharges directly into the existing 15 foot culvert via drainage inlets and pipe or runs
overland to the D-8 Tribrutary of Duhart's Creek. It also appears that the improvements have
changed slightly from the original design plans over the course of time, likely due to small
improvements that were not properly documented.
B. Identify deficiencies in the existing drainage system
The FIRM map covering the property indicates that the 100 Year flood plain encompasses a
sizable portion of the existing parking lot. The flood plain elevation is +710.0.
It must be noted and stressed that the existing system is tied directly to the Duhart's Creek.
There is no detention system. Thus the controlling factor of the existing drainage system is
the size of the pipe which comprises the conveyance system.
Similarly, the site presently has no means of providing water quality for the runoff.
Lastly, there are a number of inlets on the site that are connected to the conveyance system by
means of piped tees. The inclusion of this configuration can place limitations on the ability to
properly maintain the drainage network.
C. Desigi the proposed grading and drainage system
The paving and grading plans are included as Exhibit E on pages 17 thru 20 for reference.
The site has been divided into three pipe conveyance networks. They are briefly identified as
follows:
1. The portion of the existing system to remain. This network lies in the southeasterly
portion of the property at the northwest corner of Franklin Road and Cox Road. The
network ties directly into the 15 foot culvert pipe running thru the site. The upper end of
this hydraulic network is proposed to be redirected to the proposed detention area.
2. The portion of the site lying on the south side of Duhart's Creek. This portion of the
site includes the private thru roadway lying south of the crossing of Duhart's Creek,
Outparcel "A" (1.07 acres), and the Outparcel "B" (1.47 acres). This network will be
analyzed using a fixed tailwater elevation of +700.
3. The remainder of the developed site. This portion includes the new parking and drive
aisles, the existing parking and drive aisles serving Mary Joe's and Harris Teeter, the re-
developed portion of the site atthe northeast corner, and the balance of the private thru
roadway. This tailwater elevation for the analysis of this network will be set to the invert
elevation of the underground detention facilities.
vvooipert, inc Gaston Mali Redevelopment Project
January 2008 PP Gaston Mail, H C
D. Analyze the conveyance network
A drainage area map is included as Exhibit F on page 21. The map provides both
contributing areas and numerical identifiers, which reflect the inlet number as taken from the
construction plans. Each portion of the conveyance system is then analyzed using Hydroflow
Storm Sewers (2005)
Appendix A is the result of the hydraulic calculations. The number system employed by the
spreadsheet corresponds to the inlet numbers on the drainage area map.
Page 2 of Appendix A is the analysis of the portion of the site identified in 1.C.2 on page 9.
Assumptions have been made to include the discharge received from Outparcel "A",
Outparcel "B" and from the "Lanier Property". (Note: The Lanier Property is under different
ownership. Due to an agreement between owners, discharge from this property will be
conveyed via the drainage network running thru the private roadway.)
Page 1 of Appendix A is the analysis of the portion of the site identified in I.C.3 on page 9.
This conveyance system includes both existing and proposed drainage inlets and pipe. The
existing inlets included in this portion of the network had been connected directly to the 15
foot culvert. Consideration should be given to two factors not represented in the calculations.
First, a small detention area has been added to the northeast corner of the site. This area is
included in order to alleviate surcharging that may be experienced at upper end of the
hydraulic grade-line during periods of high intensity. Secondly, localized flooding may exist
for short durations during short storm events having a high intensity of precipitation.
The portion of the site identified in 1.C.1 on page 9 is omitted from the analysis. There is a
net reduction in contributory areas as a result of the improvements.
2. STORMWATER STORAGE AND DISCHARGE STRUCTURE DESIGN
A. Identify the drainage sub-basins
Exhibit G on page 22 is the sub-basin map. The property has been divided in accordance to
how the various areas are computed and incorporated into the surface water management
calculations. A further description of the areas and the application is provided in item 2.B.
below.
B. Categorize how the drainage sub-basins should be analyzed.
The following is a summary of the drainage sub-basins within the project limits and their
application in the analysis.
L Outparcel "A" consists of approximately 1.09 acres. The parcel is located in the
southwesterly portion of the site and fronts Franklin Boulevard. This parcel will require
stormwater management facilities and water quality provisions upon development. The
area is excluded from the analysis, but included for informational purposes using
assumed data. A drainage connection is included as shown in the proposed construction
plans. A rate of discharge from this area is assumed in the pipe sizing calculations.
2. Outparcel "B" consists of approximately 1.47 acres. The parcel is located to the north
of OutparceI A. This parcel will require stormwater management facilities and water
quality provisions upon development. The area is excluded from the analysis, but
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January 2008 PP Gaston Mall, LLC
included for informational purposes using assumed data. A drainage connection is
included as shown in the proposed construction plans. A rate of discharge from this area
is assumed in the pipe sizing calculations.
3. "Area C" consists of approximately 6.64 acres in the southeast comer of the site. The
acreage consists of existing parking areas and buildings that will remain. Runoff from
this area discharges directly to the 15 foot culvert pipe running thru the site. This area
will benefit from the addition of pervious areas throughout the parking area.
4. "Area D" consists of approximately 1.47 acres in the southwesterly portion of the site.
The area is comprised of the private thru roadway lying south of the proposed culvert /
bridge crossing. Due to the grading requirements of the roadway, providing storage and
regulating the rate of discharge (beyond pipe control) within the area limits is not
practical. Discharge from this area is anticipated to be pipe controlled. Compensating
storage and rate of discharge is proposed within Area H.
5. "Area E" consists of approximately 4.67 acres in the northwest portion of the site.
The acreage is comprised of the proposed retail 1 building, the drive aisle to the north of
the building and the bio-retention area. Runoff from the building and drive aisle will be
discharged to the bio-retention area. The design calculations for the water quality volume
to be met with the bio-retention area are included in Appendix K of this report.
6. "Area F" consists of approximately 9.12 acres. This area is comprised of Duhart's
Creek and the pervious areas contributing directly to the creek up to the 100 year flood
plain (+710.0). For the purpose of this report, the time of concentration is halved for the
post developed condition.
7. "Area G" consists of approximately 4.55 acres. The area is comprised of the existing
Mary Joe's, Harris Teeter and a portion of the existing mall building together with the
existing parking areas to the north. In the current condition, runoff from this area is
conveyed either directly to the 15 foot diameter culvert pipe via a pipe network or to the
D-8 Tributary via overland flow. As this area is presently developed and shall remain, it
is excluded from the water quality calculation. In the proposed condition, runoff from
these areas will be directed to the proposed underground detention system to be
constructed within the parking area of Retail 1. For the purpose of these calculations, the
rate and volume of runoff is based upon the existing condition having a "C" factor of
0.25.
8. "Area H" is the balance of the site. This area is comprised of the proposed parking lot
for Retail 1 and Mary Joe's, the private thru roadway lying on the north side of the
bridge, a majority of the existing building in the southeast quadrant of the property, the
proposed shops and ancillary parking at the northeast corner of the site. The combined
acreage is approximately 15.91 acres. Runoff is conveyed to the underground detention
facility to be located within the Retail 1 parking lot. Water quality will be provided for
this area.
C. Compute the detention requirement and the allowable rates of discharge.
In the post developed stage, the dominant means of conveyance to Duhart's Creek will be via
a series of pipes and inlets. Attenuation of runoff to meet the storage requirements of the site
will be accomplished through implementation of an underground detention system to be
located in the new parking area of Area "H", located in the northwesterly portion of the
property.
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January 2008 PP Gaston Mall, LLC
Certain portions of the site do not lend themselves to providing storage and limiting the rate
of discharge. These areas are defined as:
1. The private drive/road lying south of the proposed bridge due to the slope of the
roadway.
2. Portions of the existing drainage system will remain directly connected to the existing
15 diameter culvert. Replacement of the existing pipes due to inadequate sizes need to
convey runoff to the proposed underground detention is likely not the best use of
monetary resources for this project. Furthermore, the parking area being served by the
pipe connections is to remain open to the public to service the existing business.
3. Duharts Creek and the areas immediately adjacent to it. These areas are pervious and
located both within and outside the 100 year floodplain. Runoff from these areas, such
as the creek's banks and the slope transitions in the westerly part of the site, will convey
directly via overland flow to the creek. It should be noted that these areas will either be
vegetated or remain in a natural state.
The rate of discharge and the proposed underground detention system to be placed with Area
"H" will be designed to compensate for the three areas list above. That is to say, the net
result for the site will be to meet the City criteria.
Each of the eight "areas" were modeled using Pondpack software by Haestead Methods. The
modified rational method was used in order to compute the rates of discharge and volume of
attenuation required for the various storm events for each area. The time of concentration for
the undeveloped sites was developed using the Kirpich method. A multiplier of two was
used. A coefficient of runoff of 0.25 was used for undeveloped portions of the sites. The
time of concentration for the developed sites was set at 5 minutes. A coefficient of runoff of
0.85 was used for developed portions of the sites. The multiplier for the undeveloped site
coupled with a small time of concentration was selected to yield conservative results when
comparing the pre-developed and post-developed conditions.
The computations, performed using Pondpack by Haestaad Methods, are included as
Appendix B thru I. The analysis compares the pre-developed flow rates and volumes against
the post-development flow rates and volumes. The analysis is done for the 2, 10 and 25 Year
storm events. A summary of the results are as follows in Table 1 on page 13. Areas "A",
"B" and "C" are included for informational purposes only. Areas "A" and "B" are
anticipated to provide both detention and water quality prior to discharging into the private
roadway's conveyance system upon development. Line "I" is the sum of the differences for
the pre versus post rates and volume of Areas "D", 47% "G" and "H". For example, the
difference in the peak rate for the 10 year storm event for Areas "D", "F", "G" and "H" is
2.50, 2.36, 8.42 and 21.84 efs respectively. The sum, 33.43 cfs, is computed in line I at the
bottom of the table. This method is employed so the net result meets the City criteria.
Similarly, Line I identifies the design parameters for the allowable rate of discharge and/or
volume to be detained within the underground detention area. (Note: Area "E" demonstrates
a net increase in storage. An increase in rate is not applicable and therefore omitted.)
Woolpert, Inc Gaston Mall Redevelopment Project 12
January 2008 PP Gaston Mail, LC
Table 1 - Summary Tabulation
2 YEAR STORM 10 YEAR STORM 25 YEAR STORM
PEAK RATE VOLUME PEAK RATE VOLUME PEAK RATE VOLUME
(.is) (Ac Ft) (ofs) (Ac Ft) (ofs) (Ac Ft)
a
a
a OUTPARCEL 1 -1.094 Acres Note: Area shall TV it's own detentionM/OV upon development)
Proposed 3.08 0.089 3-87 0.128 4.29 0-142
Difference 1.52 0.045 1.68 0.064 207 0.070
Predeveloped 1.56 0.044 1.99 0.064 2.22 0.072
OUTPARCEL B with FUTURE BLDG 7 -1.47 Acres (Note: Area shall provide it's own detentionANOV upon development)
W Proposed 4.14 0.120 5.20 0.172 5.76 0
190
W M
Q Difference 2.05 0.061 2.53 0.086 .
2.78 0094
F
'
Predeveloped 2.09 0.059 2.67 0.086 2.98 0.096
Q AREA DIRECTLY DISCHARGING TO 15' DIA PIPE - 6.64 Acres (Note - Area has addition of landscape islands only)
W Proposed 32.1 n!a 40.98 We 45.76 nla
Difference 0:00 M
00:
Predeveloped n/a :40:9B ... nta ;:: n/a
a PORTION OF PRIVATE DRIVE -1.47 Acres
W Proposed 4.04 0.123 5.09 0.175 5.64 0
194

a Difference 2.02 0.063
I ° 2.50. ' 0.088
. .
.::::275 -99?

Predeveloped
.;`2.02' -- 0 060
2 59 7;: 0.087 ,,
"2Bg 0.097
RETAIL 1 BLDG AND ANCILLARY, BIO-RETENTION -4.67 Acres
w
W W Proposed'
Difference 0 0.366/0.306
-6 42 0.000 15.84 0.529/0.378
r 7.63 -O 3 17.58 0.581/0.379
.. 8.41' -0.082
Predeveloped 827 0.259 9a7.,; 0.285
Q DUHARTS CREEK AND CONTRIBUTING AREA - 9.12 Acres (Note - The Post To is 112 the Pre To)
W Proposed 8 0.097 17.97 0.124 20.07 0.138

Q Difference F: 1;9T 0.014 2.36 OA16 266
Predeveloped 0.083 3i= 15 61.:ic: 0.108 ->i17;41•?: 0.120
a HARRIS TEETER I MARY JO'S AND PARKING -4.55 Acres (Note- Ex Conditions uses a •C- value of 0.25 for this area)
0 Proposed
13-25
04
16.6
0.574

15.67 0.755
W

Q Difference 676
0 .210
.. 8.42
0-296
_.

.`
0.321
Ex. Conditions ,-6;47`i 0.492 -" 0.276 0.434
a PRIMARY SITE -15.91 Acres

=
I.U
Pro
55
0
105
75.85
1
M

Q D fference 16 60
0
.250
51
04323
21
24.27 `' ?' It
. `.-... _.....
Ex Conditions ' .ir.: 0.555 :1-:54.34`- 0.722 i 60:27:rf`: 0.800
SUMMARY OF HIGHLIGHTED BLOCKS IN COLUMN
Allowable peak rate of discharge from 2 2
_
Primary Development 31.10 0.537 33.43
0.723 40.00
0.800

1 Peak rate is measured as flow cresting the earthen dam of bioretention area and does not include discharge via the
infiltration. Volume shown is runoff volume and retained volume.
2 Volume does not include a net reduction in runoff volume discharged from the Retail 1as demonstrated in line E.
The acreage for the bio-retention area is included in the Line E
D. Using the summation from Table 1, design the underground detention system
According to Line I of Table 1 above, the underground detention system must provide a
minimum of 0.723 and 0.800 acre feet in the 10 year and 25 year storm event respectively.
The underground detention system consists of 2,500 lineal feet of 60" pipe and 266 lineal feet
of 48" pipe. The invert elevation of the pipes is +701.50. The volumetric equivalent of the
pipes is utilized in the routing calculations. Table 2 on page 14 lists the stage against
available storage. Using the table, the required volume and equivalent stage within the
underground detention system is,as follows:
10 Year, 1 day storm event - 0.761 Ac.Ft 4 Elevation 704.42
25 Year, 1 day storm event - 0.800 Ac-Ft -> Elevation 704.77
The underground detention system provides adequate storage capacity. Additional storage
will be required to meet the discharge requirements.
Woolpert, Inc Gaston Mail Redevelopment Project 13
January 2008 PP Gaston Mall, H C
Table 2 - Underground Detention, Stage vs. Storage
Elev. Vol.
(Ft) (ACFt)
701.55 0.00
701.60 0.01
701.65 0.01
701.70 0.02
701.75 0.02
701.80 0.03
701.85 0.04
701.90 0.05
701.95 0.05
702.00 0.06
702.05 0.07
702.10 0.08
702.15 0.09
702.20 0.10
702.25 0.12
702.30 0.13
702.35 0.14
702.40 0.15
702.45 0.16
702.50 0.18
Elev. Vol.
(Ft) (AcFt)
702.55 0.19
702.60 0.20
702.65 0.21
702.70 0.23
702.75 0.24
702.80 0.25
702.85 0.27
702.90 0.28
702.95 0.30
703.00 0.31
703.05 0.33
703.10 0.34
703.15 0.35
703.20 0.37
703.25 0.38
703.30 0.40
703.35 0.41
703.40 0.43
703.45 0.44
703.50 0.46
Elev. Vol.
(Ft) (AcFt)
703.55 0.47
703.60 0.49
703.65 0.51
703.70 0.52
703.75 0.54
703.80 0.55
703.85 0.57
703.90 0.58
703.95 0.60
704.00 0.61
704.05 0.63
704.10 0.64
704.15 0.66
704.20 0.68
704.25 0.69
704.30 0.71
704.35 0.72
704.40 0.74
704.45 0.75
704.50 0.77
STORMWATER QUALITY DESIGN
Elev. Vol.
(Ft) (AcFt)
704.55 0.78
704.60 0.80
704.65 0.81
704.70 0.83
704.75 0.84
704.80 0.86
704.85 0.87
704.90 0.89
704.95 0.90
705.00 0.91
705.05 0.93
705.10 0.94
705.15 0.95
705.20 0.97
705.25 0.98
705.30 0.99
705.35 1.01
705.40 1.02
705.45 1.03
705.50 1.04
Elev. Vol.
(Ft) (AcFt)
705.55 1.05
705.60 1.07
705.65 1.08
705.70 1.09
705.75 1.10
705.80 1.11
705.85 1.12
705.90 1.13
705.95 1.14
706.00 1.14
706.05 1.15
706.10 1.16
706.15 1.17
706.20 1.18
706.25 1.18
706.30 1.19
706.35 1.19
706.40 1.20
706.45 1.20
706.50 1.20
A. Categorize the drainage sub-basins within the project for water quality
The following is list of the areas described in section 23 of this section together with the
application of each in determining the appropriate volume requirements for stormwater
quality.
Outparcel A and B shall satisfy the requirements for water quality upon development. The
parcels are not included in these calculations.
With the exception of added landscape islands, Areas C and G shall remain virtually the same
as in the existing condition and are therefore excluded from water quality calculations. It
should be noted that runoff from Area G will be routed thru the proposed StormFilter system
located in Area H.
Area E shall satisfy the requirement for water quality through the use of the bio-retention area
located to the west of the proposed Retail 1 building. Refer to section 3.13 of this section of
the report for additional information.
Area F is Duhart's Creek, the banks and those areas that are directly connected. Area F is
excluded from water quality calculations.
Water quality shall be provided for the entirety of Area H. As previously stated, this area
includes new development, re-development and an existing building. Due to grading
constraints, providing water quality for Area D is impractical. Inclusion of the existing
building within Area H is adequate compensation for Area D.
Woolpert, Inc Gaston Mall Redevelopment Project 14
January2008 PP Gaston Mall, LLG
In summary, the area used for the water quality and the method of meeting the requirement
shall be as follows:
Area E, 4.67 acres, in a bio-retention area
Area H, 15.91 acres, in a StormFilter system
B. Prepare the water quality calculations
The water quality design is divided into two components which are segregated by the large
culvert pipe to be serviced by the D-8 tributary of Duhart's Creek.
A bio-retention system is designed to serve Area E. The design calculations for the area are
included in Appendix K of this report. The design uses the allowable depth of twelve inches
within the facility.
Water quality for Area H is met through the implementation of 102 StormFilter units by
Contech Stormwater Solutions. Runoff is initially conveyed to the underground detention
area and thru a vault which houses the StormFilter network. After the proper volume is
attained in the underground detention, runoff may discharge via a weir controlled by-pass. A
summary of the design calculation prepared by Contech is shown in Table 3 below. The
complete design calculation is included as Appendix L and M.
Table 3 - StormFilter Sizing
StormFilter Sizing - Water Qualit
Proiect Name:
Date: y Volume Based
Gaston Man
1/1712008
Input xXX
- -
aesult - XX7t
SITE CHARACTERISTIC INPUT
Design Storm, P (inches) 1.00 -
Total Area, AT (acres) 15.91
Impervious Area, Ai (acres) 13.04
Water Quality Volume, WQv (cu ft) 45489
Average Rainfall, (inches) 45
Runoff Coefficient, C 0.84
Pretreatment efficiency, (/) 30k
EMC of TSS, (mg/L)' 54.2
ANNUAL MASS LOAD CALCULATIONS
Annual Mass Load, (tbs) 6,659
Required Filter Efficiency, (%) 0.79 \lJ?Nair Ir^ 11
Allowable Load per Cartridge, (lbs) 36
Number of Cartridges Required 102
STOATir
SYSTEM DESIGN ?,? SCsLUT1®E?4S?.
Vault Size Box Culvert
vvoolperi, inc Gaston Mail Redevelopment Project 15
January 2008 PP Gaston Mail, LLC
C. Design the by-pass system for the allowable rate of discharge
The stormfilter system is designed to provide water quality. Runoff that exceeds this volume
is discharged to Duhart's Creek. The rate of discharge is limited to meet the existing
conditions. For this particular project, Area "H" not only provides additional storage to
compensate for other portions of the project, but it also compensates for the acceptable rate of
discharge.
A weir will be placed within a structure between the underground detention system and the
point of discharge to Duhart's Creek. The weir data is included in the routing calculations for
the primary site, which is included as Appendix J.
Line I of Table 1 on page 13 computes the allowable discharge rate for Area "IT'. 'The
computed rate is according to the calculations included in Appendix J. The allowable and
computed rate of discharges is as follows:
2 Year, 1 day storm event - 31.10 cfs (allowable) / 12.27 (computed)
10 Year, 1 day storm event - 33.43 cfs (allowable) / 21.52 (computed)
25 Year, 1 day storm event - 40.00 cfs (allowable) / 32.95 (computed)
The computed water surface elevation for the various storm events is as follows:
2 Year, 1 day storm event - Elevation +705.37
10 Year, 1 day storm event - Elevation +706.68
25 Year, 1 day storm event - Elevation +708.42
CONCLUSION
The City's ordinance prohibits the peak rate of discharge in the developed condition to exceed
that of the pre-developed condition for the 10 year storm event. While some of the projects sub-
basins do not meet the criteria, the project when viewed in totality does meet the city requirement.
The computations also demonstrate that the net volume discharged from the site is not increased
for the various storm events. This provision and consideration is included in the analysis due to
the sensitivity expressed by the residents downstream of the site along Duharts Creek.
The proposed system meets the allowable discharge rate criteria for the various storm events.
Finally, the existing condition also has no provision for meeting water quality requirements. The
project meets the volumetric requirements for all new construction and areas undergoing
complete re-development.
G:\SD\Ptoj acts\Gaston Mall Redevelo-t\64961 Gaston Mall\Engineecing\Sto= Design\PONDPACC\Rational - 9th set of talc's\sto-atez managment
-1-t.doc
wooipert, Inc Gaston Mall Redevelopment Project 16
January.2008 PP Gaston Mali, LLC
2/20/2008 11:29 AM Pipe Calculations 1 of 1
From To Drainage C C x A Inlet R
i R

Point

1

Point

0

Area

.276

Factor

.9

Increment

0

25

Cumm.

7
6

Time

in.
9
54 a
n
Fall

/
5
99 unoff

Q

.:.:;??:C;,;

.,•;,4(!ti`!::::

:?9.;:. ,

.::::;;:;:;:;:>:

•.;?Slapa

:::<•;;:;:o:»;;:;::

;t

>:i:i>:»s>:i:>:i:

apacity

Q
C.FS.
VEL.

by slope)
F.P.S.

low

Time
MIN.

emarks

33
31
0.48
0.9 .
0.43 .
5
68 .
8
69 .
6
22 39.37
35
35 701.50
701
6 701.50 94.0 0.00% 48 0.00 0 #DIV/0!

34
33
0.45
0.9
0
41 .
5
25 .
8
01 .
6
41 .
33
6 .
2 701.50 164.0 0.08% 48 40.48 3 0.75

35

34

0.49

0
9 .

0
44 .

4
84 .

7
72 .

6
49 .
2 701.70 701.62 120.0 0.07% 48 37.28 (3pyQ=$
Q 'pjf

36
35
0.62 .
0.9 .
0
56 .
3
31 .
7
31 .
6
60 31 Al
21 701.95 701.70 100.0 0.25% 42 50.44 5.53 0.30

37
36
0.24
0.9 .
0
22 .
2
75 .
6
80 .
6
74 .86
1 702.25 701.95 126.0 0.25% 36 33.44 5.04 0.42
. . . . 8.55 702.64 702.25 153.0 0.25% 36 33.44 785 0
53
.
J 63 0.58 0
9 0
52 1
51 6
03 6
94

l
J
0.00 .
0
9 .
0
00 .
0
99 .
5
77 .
7
01 10.47 703.25
F7 703.00
'` 95.0 0.26% 24 11.64 4.19 0.38 {j$jo-{Qj':

G
l
1.10 .
0
9 .
0
99 .
0
99 .
5
00 .
7
22 6.91 3 3 `. : 7f?3: ?¢> 45.4 0.20% 21 7.07 3.35 0.23 'A Y t ©+la; a : t+ E .:........ '

40

41-A

64

40

0.05

0.05 .

0.5

0
5 .

0.02

0
02 .

0.09

0
07 .

6.69

6
36 .

6.76

6
85 7.12

0.62 Z¢`$`?

706.20 >`09<>s

704.40 202.7

169.0 0.69%

1.07% 15

15 5.38

6.68
4.39
3.41
0. 77
0.83

... .............

41-B
41-A
0
05 .
0
5 .
0
02 .
0
05 .
.
6
04 .
6 0.47 706.75 706.20 60.0 0.92% 15 6.20 2.99 0.33

41-C
41-B .
0.05 .
0
5 .
0
02 .
0
02 .
5
00 .94
7
22 0.32 707.35 706.75 55.0 1.09% 15 6.77 2.83 0.32

62
37
0.43 .
0
9 .
0
39 .
2
54 .
6
60 .
6
79 0.17
17 707.90 707.35 110.0 0.50% 15 4.58 1.77 1.04

63
62
0.42 .
0
9 .
0
37 .
2
15 .
6
40 .
6
84 .21 702.85 702.64 68.7 0.40% 30 26.01 5.66 0.20

61
63
0.30 .
0
9 .
0
27 .
0
27 .
5
00 .
7
22 14.70 703.00 702.85 67.0 0.50% 24 16.04 5.79 0.19 A?fkl!?$p..... ?;6`iE::;:.':

58
39
0.29 .
0
9 .
0
26 .
0
64 .
5
10 .
7
19 1.92 704.24 703.75 25.5 1.00% 15 6.48 4.60 0.09

59
58
0.42 .
0
9 .
0
38 .
0
38 .
5
00 .
7
22 4.60 703.41 703.00 62.0 1.00% 18 10.53 5.76 0.18
. . . . . 2.73 703.71 703.41 30.0 1.00% 18 10.53 5.00 0.117

53 35 0
45 0
9 0
41 1
08 5
60 7
06

54
53 .
0
50 .
0
9 .
0
45 .
0
68 .
5
38 .
7
1 7.65 702.70 702.20 99.1 0.50% 24 16.04 5.05 0.33

55
58
54
31 .
0.25
0
77 .
0.9
0
9 .
0.23
0
69 .
0.23
1
07 .
5.00
5
10 .
2
7.22
7
19 4.80
1.62 703.32
704.57 702.70
703.57 74.0
100.0 0.85%
1.000% 18
15 9.71
6.48 5.48
4.39 0.23
0.38
. . . . . . 7.71 702.65 701.75 90.3 1.00% 18 10.53 6.51 0.23
Page 1
Appendix A
Gaston Mall Storm 1b.xls
2/1/2008 2:44 PM
Prniach ('a clnn 00a/1 _ I ino 9
Pipe Calculations
From To Drainage C C x A Inlet Rain Runoff Invert Elm -' i r? Iii ---
- - :,
C
it
V

Point

50
49
Point

51
50
Area

0.07
0
26
Factor

0.9
0
9
Increment

0.07
0
24
Cumm.

1.08
1
01
Time
Min.
5.66
5
58
Fall
In/Hr
7.04
Q
C.F.S.
24.15

C',?rl
700.09

L=nrl
700.00

?'
37.7

.25%

P,-
36 apac
y
Q
C.F.S.
33.44 EL.
(by slope)
F.P.S.
5.15 Flow
Time
MIN.
0.12 Remarks

48
49 .
0
17 .
0
9 .
0
15 .
0
78 .
5
41 7.06 23.70 722.18 719.50 67.0 4.00% 24 45.37 14.60 0.08

47
48 .
0
12 .
0
9 .
0
11 .
0
63 .
5
28 7.11 22.05 728.10 722.38 143.1 4.00% 24 45.37 14.34 0.17

46
47 .
0
24 .
0.9 .
0
22 .
0
22 .
5
00 7.15 19.21 740.32 728.60 146.5 8.00% 18 29.79 17.91 0.14

45
47 .
0
12
0
9 .
0
10 .
0
30 .
5
20 7.22
7 14.61 747.77 740.77 87.5 8.00% 15 18.32 16.58 0.09

44
45 .
0
22 ,
0
9 .
0
20 .
0
20 .
5 .17 11.21 746.83 740.52 76.3 8.00% 18 29.79 15.67 0.08
. . . . .00 7.22 5.11 762.00 750.00 150.1 8.00% 15 18.32 12.79 0.20
Notes:
1 Inlet 48 is calculated to convey 1.81 cfs peak flow from the "Lanier property" as a result of future development. The additional flow is included hereto.
2 Inlet 47 Is calculated to convey 1.70 cfs peak flow from the "Lanier property" as a result of future development. The additional flow is included hereto.
3 Inlet 46 is calculated to convey 3.97 cfs peak flow from the "Lanier property" as a result of future development. The additional flow is included hereto.
4 Inlet 45 is calculated.to convey 5.37 cfs peak flow from the "Future Bldg 7" as a result of future development. The additional flow is included hereto.
5 Inlet 44 is calculated to convey 3.69 cfs peak flow from the "Outparcel A" as a result of future development. The additional flow Is included hereto.
6 Actual flow rates contributing as described in notes 1 thru 5 to be determined upon development.
1 of 1
Page 2
Appendix A
Gaston Mall Storm 2.xls
2/1/2008 2:49 PM
Protect: Gaston Mall - I ina 3
Pipe Calculations
From To Drainage C C x A Inlet Rain Runoff In rel1l rwt fit ! 5/a
u C
it

Point
Point
Area
Factor
Ecrement
Cumm.
Time
Min.
-
Fall
In/Hr
Q
C.F.S
L:',7?g1
nt1-; _
i, ,., u
u,!

= , Li apac
y
Q
C.F.S. VEL.
(by slope)
F.P.S. Flow
Time
MIN. Remarks
23

B
C 24

24
B 0.28

0
0
53 0.9

0.9
0
9 0.25

0.00
0
47 0.25

2.04
2
04 5.00-

5.00
5
0
7.22
7.22
1.81
14.75

702.30

701.50 _
102.0
80.0
1.00%
1.00%
18
18
10.53
10.53
4.46
5.96
0.38
0.22
. . . . .
0 7.22 14.75 703.77 701.80 164.0 1.20% 24 85
24 8
25 0
33
D C 0.25 0.85 0.21 1.57 5.00 7.22 11.33 7Q5 66 705 09 ' 93
.7
0.61% _
10 .
85
4 .
2
75 .
0
57
E D 0.90 0.85 0.76 1.36 5.00 7.22 9.82 7R6,34 705 a8 89.2 0.54% .
57
4 .
2
56 ,
0
58
F C 0.70 0.85 0.80 0.80 5.00 7:22 4.32 7j6,q 7pEa 4h. 97.5 0.10% 8 .
1.99 .
1.'13 .
1.44
Page 3
Appendix A
1 of'I
Gaston Mall Stonn 3.xls
211/2008 2:53 PM
Pipe Calculations
Project: Gaston Mall - Line 4
From To Drainage C C x A Inlet Rain Runoff Inval
Point
29 Point
59 Area
0.09718 Factor
0
9 Increment
0
09 Cumm.

30
1 Time
Min. Fall
In/Nr
11
0? ppQr
C.F.S. -- ?'y Capacity
C.F.S. VEL.
(by slope)
F.P.S. Flow
Time
MIN

28
27

29

28

0.34

1.00
,
0.9

0.9
.
0.31

0.90
.
1.21

0,90
5.00
5.00

5.00
7.22
7.22

7.22
9.35
8.72

6
50
702.24
703.32

705
31
701.75
702.44

70
5
48.8
8
8.0
1.00%

.00%
1
18

18
10.53

10.53
6.73

6.66 .
0.12

0.22
. . 3.
7 108.9 1.60% 15 8.19 7.41 0.25
Page 4
1 of 1
Appendix A
Gaston Mall Storm 4.xls
2/112008 2:56 PM
Pipe Calculations 1 of 1
Project: Gaston Mall - Target Line
From To Drainage C C x A Inlet Rain Runoff Inver
d t E
le - ? -,,,
t
^ 777
---
Point

23 Point

2 Area

.71 Factor

.9 Increment

.54 Cumm.

1
54 Time
Min. _

5
00 Fall
In/1 tr

7
22 Q
C. F. S

11 (,;, "

_ ?
- T

. Capacity
Q
C. F. S. VEL.
(by slope)
F. P. S. Flow
Time
MIN. Remar/cs

22 -

21 ---- -

O.BO -

0.9 -

0.72 ,
----
2
28 .
---
5
00 .

7
22 .11

16
31 706.99 705.59 93.0 1.50% 18 12.90 8.21 0.19
'-?
7
e QC' 71,
itr
21

19
1 19

1
18 0.00

0.00
0.657 0,9

0:9
0.9 0.00

0.00
0.59 .
2.26
2.26
6.89 .
5.00
5.00
5.00 .
7.22
7.22
7.22 .
16.31
16.31
49.75 705.59
704.94
704.51
703.32 704.94
704.51
703.32
703.00 65.0
43,0
1190
32.0 1.00%
1.00%
1.00%
1.00% 24
30
30
30 22.68
41.13
41.13
41.13 _7.86
7.89
7.89
8.38 0.14
0.09
0.25
0.06

. ;
3a
3
2 3
2
1 0,02
0.22
0.05 0.9
0.9
0.9 0.02
0.20
0.05 0,02
4.00
4,04 5.00
5.00
5.00 7.22
7.22
7.22 0.13
28.85
29.17 707.96
706.05
703.28 706.80
703.53
702.00 116.0
252.0
128.0 1.00%
1.00%
1.00% 15
24
24 6.48
22.68
22.68 2.09
7.22
7.22 0.92
0.58
0.30

1
4 3 0.51 0.9 0.46 3.78 5.00 7.22 27.29 710.41 706.30 411.0 1.00% 24 22
68 7
22 0
95
. . .
9
8 8
7 0.56
0.00 0.9
0.9 0.50
0
00 0.50
0
50 5.00
5
00 7.22
7
22 3.62 704.89 704.89 74.7 O.DO°,o 15 0.00 0.00
7
6 6
5 1.01
1.04 0.9
0
9 .
0.91
0
94 .
1.41
2
35 .
5.00
5
00 .
7.22 3.62
10.19 704.89
704.89 704.89
704.89 57.3
'124.0 0,009c
O.OU°'° 36
36 0.00
0.00 0.00
0.00 A
5 4 1.075 .
0
9 .
0
97 .
3
32 .
5
00 7.22 16.97 704.89 704.89 124.0 0.00°l0 36 0.00 0.00

.
.
.
.
7.22
23.96
70489
704.89
111.0
U.00'Su
36
000
0.00 #DIV/OI
Page 5
Appendix A
Gaston Mall Storm new lar0et.xls
"OUTPARCEL A"
Table of Contents
xxxxxxx*xxxxxxxxxxxxxx MASTER SUMMARY xxxxxxxxxxxxxxxxxxxxxx
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
*xxxxxxxxxxxxxxxxxxxxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table 2.01
2 year Gastonia 2 Yr I-D-F Table ........................ 2.02
25 Year Gastonia 25 Yr I-D-F Table 2.03
+xxxxxxxxxxxxxxxxxxxxxx HYG ADDITION xxxxxxxxxxxxxxxxxxxxxxx
OUT 10.......... 2 Yr Node: Addition Summary ............. 3.01
OUT 10.......... 10 Yr Node: Addition Summary ............. 3.03
OUT 10.......... 25 Yr Node: Addition Summary ............. 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING *xxxxxxxxxxxxxxxxxxxxxx
OUTPARCEL A IN 2 Yr Node: Pond Inflow Summary .......... 4.01
OUTPARCEL A IN 10 Yr Node: Pond Inflow Summary .......... 4.03
OUTPARCEL A IN 25 Yr Node: Pond Inflow Summary .......... 4.05
****************** RATIONAL METHOD CALCS *******************
OUTPARCEL A..... PRE C and Area ..................... 5.01
OUTPARCEL A..... 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Hyg .................. 5.03
OUTPARCEL A..... POST C and Area .................... 5.04
OUTPARCEL A..... 10 Yr
Rational Predev. Peak Q ....... :.... 5.05
Mod. Rational Hyg .................. 5.06
OUTPARCEL A..... 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Hyg .................. 5.08
OUTPARCEL A APPENDIX B
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational 3 set of calc's\RATIONAL OUTPARCEL A.PPW
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
x
x
x
x
* MODIFIED RATIONAL METHOD x
x ---- Grand Summary For All Storm Frequencies ----
x
*
x
x
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxxxxxx
*xxxxxxxxxxxxx:txxxx*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxx**xxxxxxxxx
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Area = 1.094 acres Tc = .0833 hrs
.............
VOLUMES
Freq. Adjusted Duration I Qpeak Allowable) Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
------------ cfs
---- cfs ac-ft
- ac-ft

2 .850
.3500
3.2880 --
3.08 --------------
1.56 ---
----
.089 ----------
.045
10 .850 .4000 4.1240 3.87 1.99 .128 .064
25 .850 .4000 4.5720 4.29 2.22 .142 .070
OUTPARCEL A APPENDIX B
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID Gastonia
Rainfall
Return Event Type IDF ID
------------ --------------- ----------------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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

*OUT 10
JCT
2 -
.089 ---------
.0833 --------
3.08 -------- ------------
*OUT 10 JCT 10 .128 .0833 3.87
*OCT 10 JCT 25 .142 .0833 4.29
OUTPARCEL A AREA 2 .089 .0833 3.08
OUTPARCEL A AREA 10 .128 .0833 3.87
OUTPARCEL A AREA 25 .142 .0833 4.29
OUTPARCEL A IN POND 2 .089 .0833 3.08
OUTPARCEL A IN POND 10 .128 .0833 3.87
OUTPARCEL A IN POND 25 .142 .0833 4.29
OUTPARCEL A OUT POND 2 .089 .0833 3.08
OUTPARCEL A OUT POND 10 .128 .0833 3.87
OUTPARCEL A OUT POND 25 .142 .0833 4.29
OUTPARCEL A APPENDIX B
Page 3 of 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
--------- Intens., in/hr
--
.0833 -----------
7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F.Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
--

.0833 ---------
5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
----

.0833 -------
8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
OUTPARCEL A APPENDIX B
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS OUTPARCEL A IN INLETS 2 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS 2 Yr .089 .0833 3.08
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 2 Yr .089 .0833 3.08
Type.... Node: Addition Summary Page 3.02
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 3.08 cfs
Time to Peak = .0833 hrs
HYG Volume = .089 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------I-----------------------------------------
---------------------
.0000 I .00 3.08 3.08 3.08 3.08
.4165 I .62 .00
OUTPARCEL A APPENDIX 6
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS OUTPARCEL A IN INLETS 10 Yr
INFLOWS TO: OUT 10
------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
------------------------------------------------------------------------
INLETS 10 Yr .128 .0833 3.87
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 10 Yr .128 .0833 3.87
Type.... Node: Addition Summary Page 3.04
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 3.87 cfs
Time to Peak = .0833 hrs
HYG Volume = .128 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time i Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I---------------------------------------------
-----------------
.0000 I .00 3.87 3.87 3.87 3.87
.4165 I 3.10 .00
OUTPARCELA
Page 6 of 16
APPENDIX B
J
Type.... Node: Addition Summary Page 3.05
Name.... OUT 10 Event: 25 yr
File.... C:\Gaston Mail Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
------------------------------------------- -----------

INLETS OUTPARCEL A IN ---------------------
INLETS 25 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft
-------------------------------------
---------- hrs cfs
-
---
INLETS 25 Yr .142 -----------------------
,0833 4.29
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft
-------------------------------------------- hrs cfs
--------
OUT 10 25 Yr .142 ----------------------
.0833 4.29
Type.... Node: Addition Summary Page 3.06
Name..., OUT 10 Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 25 Yr
---------
--------------------------
Peak Discharge = 4.29 cfs
- Time to Peak = .0833 hrs
HYG Volume = .142 ac-ft
------------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first
--------- I----------------------------- value in each row.
-------------
.0000 I .00 4.29 4.29 -•-------------------
4.29 4.29
.4165 I 3.44 .00
OUTPARCEL A
APPENDIX B
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... OUTPARCEL A IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUTP_z1RCEL A IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
------------------------------------------------ -------------------------
ADDLINK 20 OUTPARCEL A OUTPARCEL A 2 Yr
INFLOWS TO: OUTPARCEL A IN
--------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
oUTPARCEL A 2 Yr .089 .0833 3.08
TOTAL FLOW INTO: OUTPARCEL A IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------
OUTPARCEL A IN 2 Yr .089 .0833 3.08
Type.... Node: Pond Inflow Summary Page 4.02
Name.... OUTPARCEL A IN Event: 2 yr
File.:.. C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUTPARCEL A IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 3.08 cfs
Time to Peak = .0833 hrs
HYG Volume = .089 ac-ft
-----------------------------------
HYDROCRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I---------------------------------------------
-----------------
.0000 I .00 3.08 3.08 3.08 3.08
.4163 I .62 .00
OUTPARCELA
Page 8 of 16
APPENDIX B
Type.... Node: Pond Inflow Summary Page 4.03
Name.... OUT-PARCEL A IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUTPARCEL A IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 OUTPARCEL A OUTPARCEL A 10 Yr
INFLOWS TO: OUTPARCEL A IN
---------- ------------------ -
-- ---
- - Volume Peak Time Peak Flow
HYG file
----------- H..G ID
------------------ =
HYG
---- g
to
------ ac-ft
----- hrs cfs

OUTPARCEL A
10
Yr ------
.128 -------------
.0833 -----------
3.87
TOTAL FLOW INTO: OUTPARCEL A IN
----------- ------------------- ---- ---- - Volume Peak Time Peak Flow
HYG file
----------- HYG ID
------------------- HYG
---- tag
----- ac-ft
---- hrs cfs

OUTPARCEL A IN
10
Yr -------
.128 -------------
.0833 -----------
3.87
Type.... Node: Pond Inflow Summary Page 4.04
Name.... OUTPARCEL A IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 10 Year. Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUTPARCEL A IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 3.87 cfs
Time to Peak = .0833 hrs
HYG Volume = .128 ac-ft
------------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs 1 Time on left represents time for first value in each row.
--------- I---------------------------------------------
.0000 1 .00 3.87 3.87 3.87 3.87
.4165 1 3.10 .00
OUTPARCELA
APPENDIX B
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name..... OUTP_ARCEL A IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of Calc's\RATIONAL OUTPARCEL A.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUTPARCEL A IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
------------------------------------------------------------------------
ADDLINK 20 OUTPARCEL A OUTPARCEL A 25 Yr
INFLOWS TO: OUTPARCEL A IN
--------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-----------------------------------------------------------------------
OUTPARCEL A 25 Yr .142 .0833 4.29
TOTAL FLOW INTO: OUTPARCEL A IN
------------------------------------ Volume Peak Time Peak Flow
HYG file HYG ID H G tag ac-ft hrs cfs
--------------------------------------------------------------------
OUTP_ARCEL A IN 25 Yr .142 .0833 4.29
Type.... Node: Pond Inflow Summary Page 4.06
Name.... OUTPARCEL A IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUTPARCEL A IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 4.29 cfs
Time to Peak = .0833 hrs
HYG Volume = .142 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (Cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
------ I-------------------------------------------------------------
.0000 .00 4.29 4.29 4.29 4.29
.4165 I 3.44 .00
OUTPARCEL A APPENDIX B
Page 10 of 16
Type.... C and Area Page 5.01
Name.... OUTPARCEL A Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
RATIONAL, C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Predeveloped Condition .2500 1.094 .274
WEIGHTED C & TOTAL AREA ---> .2500 1.094 .274
OUTPARCEL A APPENDIX B
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name:... OUTPARCEL A Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD-PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .0833 hrs
-----------------------------
Tag Freq C C adj I C I Area Peak Q
(years) factor final in/hr acres 1 cfs
----- ------ -----
2 Yr 2 .250 1.000 1 .250 5.6400 1.094 1 1.56
-----------------------------
Type.... Mod. Rational Hyg Page 5.03
Name.... OUTPARCEL A Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Td = .3500 hrs
------------------------------
Tag Freq C C adj I C I Area 1 Peak Q
(years) factor 1 final in/hr acres 1 cfs
----- ------ -----
2 Yr 2 .850 1.000 1 .850 3.2880 1.094 I 3.08
-----------------------------
HYG file =
HYG ID = OUTPARCEL A
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 3.08 cfs
Time to Peak = .0833 hrs
HYG Volume = .089 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (Cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I----------------
---------------------------------------------
.0000 1 .00 3.08 3.08 3.08 3.08
.4165 1 .62 .00
OUTPARCEL A APPENDIX B
Page 12 of 16
Type.... C and Area Page 5.04
Name.... OQTPARCEL A Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Bldg 7 Development .8500 1.094 .930
WEIGHTED C & TOTAL AREA ---> .8500 1.094 .930
OUTPARCEL A APPENDIX B
Page 13 cf 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... OUTPARCEL A Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .0833 hrs
----------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I-----------------------------
10 Yr 10 .250 1.000 1 .250 7.2000 1.094 1.99
-----------------------------
Type.... Mod. Rational Hyg Page 5.06
Name.... OUTPARCEL A Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Td = .4000 hrs
.-----------------------------
Tag Freq C C adj C I Area I Peak Q
(years) factor I final in/hr acres 1 cfs
----- ------ ----- ------ I ----------------------------- I ----------
10 Yr 10 .850 1.000 1 .850 4.1240 1.094 3.87
-----------------------------
HYG file =
HYG ID = OUTPARCEL A
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 3.87 cfs
Time to Peak = .0833 hrs
HYG Volume = .128 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 1 .00 3.87 3.87 3.87 3.87
.4165 1 3.10 .00
OUTPAROELA
APPENDIX B
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... OUTPARCEL A Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL A.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .0833 hrs
.-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I----------------------------
25 Yr 25 .250 1.000 I .250 8.0400 1.094 2.22
-----------------------------
Type.... Mod. Rational Hyg Page 5.08
Name.... OUTPARCEL A Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Td = .4000 hrs
.-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ i----------------------- =-
--I
25 Yr 25 .850 1.000 I .850 4.5720 1.094 I 4.29
-----------------------------
HYG file =
HYG ID = OUTPARCEL A
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 4.29 cfs
Time to Peak = .0833 hrs
HYG Volume = .142 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time'increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------I--------------------------------------------------------------
.0000 I .00 4.29 4.29 4.29 4.29
.4165 I 3.44 .00
OUTPARCEL A APPENDIX B
Page 15 of 16
Appendix A A-1
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- 0 -----
OUT 10 2 Yr... 3.01, 3.03, 3.05
OUTPARCEL A PRE... 5.01, 5.02, 5.03,
5.04, 5.05, 5.06, 5.07, 5.08
OUTPARCEL A IN 2 Yr... 4.01, 4.03,
4.05
----- W -----
Watershed... 1.01, 1.02
OUTPARCEL A APPENDIX 6
Page 16 of 16
"OUTPARCEL B"
Table of Contents
xxxxxxxxxxxxxxxxxxxxx MASTER SUMMARY
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary 1.02
xxxxxxxxxxxxxxxxxxxxxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ........................ 2.01
2 year Gastonia 2 Yr I-D-F Table ........................ 2.02
25 Year Gastonia 25 Yr I-D-F Table ........................ 2.03
xxxxx+xxxxxxxxxxxxxxx** POND ROUTING xxxxxxxxx+xxxxxxxxxxxxx
SITE IN 2 Yr Node: Pond Inflow Summary .......... 3.01
SITE IN 10 Yr Node: Pond Inflow Summary .......... 3.03
SITE IN 25 Yr Node: Pond Inflow Summary .......... 3.05
xxxxxxxxxxxxxxxxxx RATIONAL METHOD CALCS xxxxxxxxxxxxxxxxxxx
OUTPARCEL B...... PRE C and Area ........................ 4.01
OUTPARCEL B...... 2 Yr
Rational Predev. Peak Q ............ 4.02
Mod. Rational Hyg ................ 4.03
OUTPARCEL B...... POST C and Area ...................... 4.04
OUTPARCEL B...... 10 Yr
Rational Predev. Peak Q ............ 4.05
Mod. Rational Hyg .................. 4.06
OUTPARCEL B...... 25 Yr
Rational Predev. Peak Q ............ 4.07
Mod. Rational Hyg .................. 4.08
OUTPARCEL B APPENDIX C
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL OUTPARCEL B.PPW
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxx*xxxxxxxxxxxxxxx
*
x
*
x
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
x
x
x
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx**xx*xxxxxxxxx*xx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxxxxx*xx:xxxxxxxxxx+**xxxxxxxx*xxxx
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Area = 1.470 acres Tc = .0833 hrs
VOLUMES
Freq. Adjusted Duration I Qpeak Allowablei Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
------------ cfs cfs I ac-ft ac-ft

2 .850
.3500
3.2880 -------
4.14 ---------- ---
2.09 I --------
.120 ----------
.061
10 .850 .4000 4.1240 5.20 2.67 ( .172 .086
25 .850 .4000 4.5720 5.76 2.98 I .190 .094
OUTPARCEL B APPENDIX C
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.:.. C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID Gastonia
Rainfall
Return Event Type IDF ID
------------ --------------- ----------------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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

OUTPARCEL B
AREA 2
.120 -
------
.0833 -------- -------- ------------
4.14
OUTPARCEL B AREA 10 .172 .0833 5.20
OUTPARCEL B AREA 25 .190 .0833 5.76
*OUT 10 AT 2 .120 .0833 4.14
*OUT 10 JCT 10 .172 .0833 5.20
*OUT 10 JCT 25 .190 .0833 5.76
SITE IN POND 2 .120 .0833 4.14
SITE IN POND 10 .172 .0833 5.20
SITE IN POND 25 .190 .0833 5.76
SITE OUT POND 2 .120 .0833 4.14
SITE OUT POND 10 .172 .0833 5.20
SITE OUT POND 25 .190 .0833 5.76
OUTPARCEL B APPENDIX C
Page 3 d 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of caic's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.....I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
---

.0833 --------
5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mali Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
---

.0833 --------
8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
OUTPARCEL B
Page 4 of 16
APPENDIX C
Type.... Node: Addition Summary Page 3.01
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 2 Yr
INFLOWS T0: OUT 10
-------------------------------------- Volume
HYG file HYG ID HYG tag ac-ft
------------------------------------------------
INLETS 2 Yr .120
TOTAL FLOW INTO: OUT 10
Peak Time Peak Flow
hrs cfs
----------------------
.0833 4.14
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs AS
-------------------------------------------------------------------------.
OUT 10 2 Yr .120 .0833 4.14
Type.... Node: Addition Summary Page 3.02
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.14 cfs
Time to Peak = .0833 hrs
HYG Volume = .120 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 I .00 4.14 4.14 4.14 4.14
.4165 I .84 .00
OUTPARCEL B APPENDIX C
Page 5 d 16
Type.... Node: Addition Summary Page 3.03
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mail Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 10 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS 10 Yr .172 .0833 5.20
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 10 Yr .172 .0833 5.20
Type.... Node: Addition Summary Page 3.04
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.20 cfs
Time to Peak = .0833 hrs
HYG Volume = .172 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time ?. Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I------------------------------------------------------------
.0000 I .00 5.20 5.20 5.20 5.20
.4165 I 4.17 .00
OUTPARCEL B APPENDIX C
Page 6 of 16
Type.... Node: Addition Summary Page 3.05
Name.... OUT 10 Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 25 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS 25 Yr .190 .0833 5.76
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag _ ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 25 Yr .190 .0833 5.76
Type.... Node: Addition Summary Page 3.06
Name.... OUT 10 Event: 25 yr
File.... Q \Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 5.76 cfs
Time to Peak = 0833 hrs
HYG Volume = .190 ac-ft
------------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
---------I-------------------------------------------------------------
.0000 .00 5.76 5.76 5.76 5.76
.4165 4.62 .00
OUTPARCEL B APPENDIX C
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 OUTPARCEL B OUTPARCEL B 2 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
OUTPARCEL B 2 Yr .120 .0833 4.14
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SITE IN 2 Yr .120 .0833 4.14
Type.... Node: Pond Inflow Summary Page 4.02
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAI, FUTURE BLDG 7.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.14 cfs
Time to Peak = .0833 hrs
HYG Volume = .120 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I-------------------------------------------------------
.0000 .00 4.14 4.14 4.14 4.14
.4165 .84 .00
OUTPARCEL B APPENDIX C
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 OUTPARCEL B OUTPARCEL B 10 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUTP_ARCEL B 10 Yr .172 .0833 5.20
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
SITE IN 10 Yr .172 .0833 5.20
Type.... Node: Pond Inflow Summary Page 4.04
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG '7.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.20 cfs
Time to Peak = .0833 hrs
HYG Volume = .172 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs j Time on left represents time for first value in each row.
--------- I --------------------------------------------------------------
.0000 I .00 5.20 5.20 5.20 5.20
.4165 I 4.17 .00
OUTPARCEL B APPENDIX C
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 OUTPARCEL B OUTPARCEL B 25 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUTPARCEL B 25 Yr .190 .0833 5.76
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
----------------------------------------------------------------=----------
SITE IN 25 Yr .190 .0833 5.76
Type.... Node: Pond Inflow Summary Page 4.06
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 25 Yr y._
-----------------------------------
Peak Discharge = 5.76 cfs
Time to Peak = .0833 hrs
HYG Volume = .190 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I--------------------------------------------------------------
.0000 .00 5.76 5.76 5.76 5.76
.4165 4.62 .00
OUTPARCEL B APPENDIX C
Page 10 of 16
Type.... C and Area Page 5.01
Name.... OUTPARCEL B Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ---------
Predeveloped Condition .2500 1.470 .368
WEIGHTED C & TOTAL AREA ---> .2500 1.470 .368
OUTPARCEL B APPENDIX C
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... OUTPARCEL B Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .0833 hrs
.-----------------------------
Tag Freq C C adj I C I Area ( Peak Q
(years) factor I final in/hr acres I cfs
----- ------ -----
2 Yr 2 .250 1.000 I .250 5.6400 1.470 2.09
-----------------------------
Type.... Mod. Rational Hyg Page 5.03
Name.... OUTPARCEL B Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Td = .3500 hrs
.-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ----------
2 Yr 2 .850 1.000 1 .850 3.2880 1.470 I 4.14
-----------------------------
HYG file =
HYG ID = OUTPARCEL B
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.14 cfs
Time to Peak = .0833 hrs
HYG Volume = .120 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
------i--------------------------------------------------------------
.0000 I .00 4.14 4.14 4.14 4.14
.4165 I .84 .00
OUTPARCEL B APPENDIX C
Page 12 of 16
Type.... C and Area Page 5.04
Name.... OUTPARCEL B Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
RATIONAL C COEFFICIENT DATA
.........................................................................
.........................................................................
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Bldg 7 Development .8500 1.470 1.250
WEIGHTED C & TOTAL AREA ---> .8500 1.470 1.250
.........................................................................
.........................................................................
OUTPARCEL B APPENDIX C
Page 13 of 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... OUTPARCEL B Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .0833 hrs
-----------------------------
Tag Freq C C adj C I Area Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .250 1.000 .250 7.2000 1.470 I 2.67
-----------------------------
Type.... Mod. Rational Hyg Page 5.06
Name.... OUTPARCEL B Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Td = .4000 hrs
-----------------------------
Tag Freq C C adj I C I Area i Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .850 1.000 I .850 4.1240 1.470 I 5.20
-----------------------------
HYG file =
HYG ID = OUTPARCEL B
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.20 cfs
Time to Peak = .0833 hrs
HYG Volume = .172 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time,increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------=-----------------------------------
.0000 ( .00 5.20 5.20 5.20 5.20
.4165 I 4.17 .00
OUTPARCEL B APPENDIX C
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... OUTPARCEL B Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL FUTURE BLDG 7.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .0833 hrs
-----------------------------
Tag Freq C C adj C I Area I Peak Q
(years) factor final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I --------
25 Yr 25 .250 1.000 1 .250 8.0400 1.470 1 2.98
-----------------------------
Type.... Mod. Rational Hyg Page 5.0B
Name.... OUTPARCEL B Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Td = .4000 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I ----------------------------- I ----------
25 Yr 25 .850 1.000 1 .850 4.5720 1.470 5.76
-----------------------------
HYG file =
HYG ID = OUTPARCEL B
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 5.76 cfs
Time to Peak = .0833 hrs
HYG Volume = .190 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 5.76 5.76 5.76 5.76
.4165 I 4.62 .00
OUTPARCEL B APPENDIX C
Page 15of16
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr.... 2.03
----- F -----
OUTPARCEL B PRE... 5.01, 5.02, 5.03,
5.04, 5.05, 5.06, 5.07, 5.08
----- 0 -----
OUT 10 2 Yr... 3.01, 3.03, 3.05
----- S -----
SITE IN 2 Yr... 4.01, 4.03,
4.05
----- W -----
Watershed... 1.01, 1.02,
A-1
OUTPARCEL B APPENDIX C
Page 16 of 16
AREA C
(Portion of site directly connected
To 151 diameter culvert)
Table of Contents
xxxxxxxxxx+xxxxxxxxxxx MASTER SUMMARY xxxxxxx*xxxxxxxxxxxxxx
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
xxxxxxxxxxxxxxxxxxxxxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ........................ 2.01
2 year Gastonia 2 Yr I-D-F Table 2.02
25 Year Gastonia 25 Yr I-D-F Table ........................ 2.03
xxxxxxxxxx*xxxxx+xx***+ HYG ADDITION ******xxxxxxxxxxxxxxxxx
OUT 10.......... 2 Yr Node: Addition Summary ............. 3.01
OUT 10.......... 10 Yr Node: Addition Summary ............. 3.03
OUT 10.......... 25 Yr Node: Addition Summary ............. 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING xxxxxxxxxxxxxxxxxxxxxxx
INLETS IN 2 Yr Node: Pond Inflow Summary .......... 4.01
INLETS IN 10 Yr Node: Pond Inflow Summary .......... 4.03
INLETS IN 25 Yr Node: Pond Inflow Summary .......... 4.05
xxxxx*xxxx*xxxxxxx RATIONAL METHOD CALCS xxxxxxxxxxxxxxxxxxx
AREA C
C and Area 5.01
AREA C 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Hyg .................. 5.03
AREA C POST
C and Area ......................... 5.04
AREA C 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational Hyg .................. 5.06
AREA C 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Hyg .................. 5.08
AREA C APPENDIX D
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of caic's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
*xxxxxxxxxxxxxxrxxx**xxxx**xxx***xxx*xxxx*xx*xx*:xx**x:xxx**xxx*xxx*xxxx
*xxxxxxxx**xxxxxxxx*xxxxxx**xxx*xxxxxxxxxxxxxxx*xxx***xxx****xxxxxxxxxxx
x
x
x
x
x MODIFIED RATIONAL METHOD
x ---- Grand Summary For All Storm Frequencies ----
x
x
x
x
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxx*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Area = 5.770 acres Tc = .0833 hrs
VOLUMES „
Freq. Adjusted Duration I Qpeak Allowablel Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
--------- cfs cfs I ac-ft ac-ft
2 .850 .4000 3.0520 15..09 6.03 1 .499 .304
10 .850 .6333 3.2680 16.16 7.82 I .846 .444
25 .850 .6667 3.5700 17.65 8.69 1 .973 .502
AREA C APPENDIX D
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID Gastonia
Rainfall
Return Event Type IDF ID
------------ --------------- ----------------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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

INLETS
IN
POND
2
.499
.0833 -------
15.09 -------- ------------
INLETS IN POND 10 .846 .0833 16.16
INLETS IN POND 25 .973 .0833 17.65
INLETS OUT POND 2 .499 .0833 15.09
INLETS OUT POND 10 .846 .0833 16.16
INLETS OUT POND 25 .973 .0833 17.65
*OUT 10 JCT 2 .499 .0833 15.09
*OUT 10 JCT 10 .846 .0833 16.16
*OUT 10 JCT 25 .973 .0833 17.65
AREA C AREA 2 .499 .0833 15.09
AREA C AREA 10 .846 .0833 16.16
AREA C AREA 25 .973 .0833 17.65
AREA C APPENDIX D
Page 3of16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
--------

.0833 ---
7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
--------

.0833 ---
5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
------

.0833 -----
8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA C APPENDIX D
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 2 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
DIRECT CONNECT 2 Yr .499 .0833 15.09
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG.tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 2 Yr .499 .0833 15,09
Type.... Node: Addition Summary Page 3.02
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE. PPW
Storm..-. 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 15.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .499 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 .00 15.09 15.09 15.09 15:09
.4165 I 12.10 .00
AREA C APPENDIX D
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... OUT 10 Event: 10 yr
File.... C.:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 10 Yr
INFLOWS TO: OUT 10
---------------------------
HYG file HYG ID
---------------------------
DIRECT CONNECT
---------- Volume
HYG tag ac-ft
---------------------
10 Yr .846
Peak Time Peak Flow
hrs cfs
----------------------
.0833 16.16
TOTAL FLOW INTO: OUT 10
------------------------
HYG file HYG ID
------------------------
OUT 10
----------- Volume
HYG tag ac-ft
--------------------
10 Yr .846
Peak Time Peak Flow
hrs cfs
---------------------
.0833 16.16
Type.... Node: Addition Summary Page 3.04
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 16.16 cfs
Time to Peak = .0833 hrs
HYG Volume = .846 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------
.0000 I .00 16.16 16.16 16.16 16.16
.4165 I 16.16 16.16 16.16 9.75 .00
AREA C APPENDIX D
Page 6 of 16
Type.... Node: Addition Summary Page 3.05
Name.... OUT 10 Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 25 Yr
INFLOWS TO! OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
DIRECT CONNECT 25 Yr .973 .0833 17.65
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 25 Yr .973 .0833 17.65
Type.... Node: Addition Summary Page 3.06
Name.... OUT 10 Event: 25 yr
File.... CAGaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge 17.65 cfs
Time to Peak = .0833 hrs
HYG Volume = .973 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time i Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 I .00 17.65 17.65 17.65 17.65
.4165 I 17.65 17.65 17.65 17.65 .06
.8330 I .00
AREA C APPENDIX D
Page 7d 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... INLETS IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
------------------------- ------------------------------------------------
ADDLINK 20 SE PART OF SITE SE PART OF SITE 2 Yr
INFLOWS TO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SE PART OF SITE 2 Yr .499 .0833 15.09
TOTAL FLOW INTO: INLETS IN
--------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS IN 2 Yr .499 .0833 15.09
Type.... Node: Pond Inflow Summary Page 4.02
Name.... INLETS IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 2 Y-r
-----------------------------------
Peak Discharge = 15.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .499 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 .00 15.09 15.09 15.09 15.09
.4165 12.10 .00
AREA C APPENDIX D
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... INLETS IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 10 Year Gastonia Taa: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 SE PART OF SITE SE PART OF SITE 10 Yr
INFLOWS TO: INLETS IN
--------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SE PART OF SITE 10 Yr .846 .0833 16.16
TOTAL FLOW INTO: INLETS IN
--------- ----------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS IN 10 Yr .846 .0833 16.16
Type.... Node: Pond Inflow Summary Page 4.04
Name.... INLETS IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 16.16 cfs
Time to Peak = .0833 hrs
HYG Volume = .846 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 .00 16.16 16.16 16.16 16.16
.4165 16.16 16.16 16.16 9.75 .00
AREA C APPENDIX D
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... INLETS IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 SE PART OF SITE SE PART OF SITE 25 Yr
INFLOWS TO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
SE PART OF SITE 25 Yr .973 .0833 17.65
TOTAL FLOW INTO: INLETS IN
---- ---------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS IN 25 Yr .973 .0833 17.65
Type.... Node: Pond Inflow Summary Page 4.06
Name.... INLETS IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 17.65 cfs
Time to Peak = .0833 hrs
HYG Volume = .973 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------I--------------------------------------------------------------
.0000 I .00 17.65 17.65 17.65 17.65
.4165 I 17.65 17.65 17.65 17.65 .06
.8330 I .00
AREA C APPENDIX D
Page 10 of 16
Type.... C and Area Page 5.01
Name.... SE PART OF SITE Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
RATIONAL C COEFFICIENT DATA
. ...................................................
-------------------------------------------------------------------------
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Developed portion at SE corner conn .2500 5.770 1.443
WEIGHTED C & TOTAL AREA ---> .2500 5.770 1.443
AREA C APPENDIX D
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... SE PART OF SITE Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .2032 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I --------
2 Yr 2 .250 1.000 I .250 4.1434 5.770 I 6.03
-----------------------------
Type.... Mod. Rational Hyg Page. 5.03
Name.... SE PART OF SITE Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ---------
2 Yr 2 2 year Gastonia -`
Td = .4000 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor i final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------i ----------
2 Yr 2 .850 1.000 I .850 3.0520 5.770 I 15.09
-----------------------------
HYG file =
HYG ID = SE PART OF SITE
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 15.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .499 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------I----------------------
.0000 I .00 15.09 15.09 15.09 15.09
.4165 I 12.10 .00
AREA C APPENDIX D
Page 12 of 16
Type.... C and Area Page 5.04
Name.... SE PART OF SITE Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Developed portion at SE corner cone .8500 5.770 4.905
WEIGHTED C & TOTAL AREA ---> .8500 5.770 4.905
AREA C APPENDIX D
Page 13 of 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... SE PART OF SITE Event: 10 yr
File:... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .2032 hrs
-----------------------------
Tag Freq C C adj I C I Area Peak Q
(years) factor final in/hr acres 1 cfs
----- ------ ----- ------ i-----------------------------I
10 Yr 10 .250 1.000 .250 5.3761 5.770 1 7.82
-----------------------------
Type.... Mod. Rational Hyg Page 5.06
Name.... SE PART OF SITE Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Td = .6333 hrs
.-----------------------------
Tag Freq C C adj C I Area Peak Q.
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ---------
10 Yr 10 .850 1.000 I .850 3.2680 5.770 1 16.16
--------------------------
HYG file =
HYG ID = SE PART OF SITE
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 16.16 cfs
Time to Peak = .0833 hrs
HYG Volume = .846 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I- Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 16.16 16.16 16.16 16.16
.4165 1 16.16 16.16 16.16 9.75 .00
Type.... Rational Predev. Peak Q Page 5.07
AREA C
Page 14 of 16
APPENDIX D
Name.... SE PART OF SITE Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\RATIONAL DIRECTLY CONNECTED TO
PIPE.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .2032 hrs
-----------------------------
Tag Freq C C adj C I Area Peak Q
(years) factor final in/hr acres cfs
----- ------ ----- ----------------------------------- I --------
25 Yr 25 .250 1.000 .250 5.9751 5.770 8.69
-----------------------------
Type.... Mod. Rational Hyg Page 5.08
Name.... SE PART OF SITE Tag: 25 Yr Event: 25 Vr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------- ----------------
25 Yr 25 25 Year Gastonia
Td = .6667 hrs
------------------------------
Tag Freq C C adj C I Area Peak Q
(years) factor final in/hr acres cfs
----- ------ ----- ------ I-----------------------------I --------
25 Yr 25 .850 1.000 .850 3.5700 5.770 17.65
-----------------------------
HYG file =
HYG ID = SE PART OF SITE
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 17.65 cfs
Time to Peak = .0833 hrs
HYG Volume = .973 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------
-----------------
.0000 .00 17.65 17..65 17.65 17.65
.4165 17.65 17.65 17.65 17.65 .06
.8330 I .00
AREA C APPENDIX D
Page 15 of 16
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia.25 Yr... 2.03
----- I -----
INLETS IN 2 Yr... 4.01, 4.03,
4.05
----- 0 -----
OUT 10 2 Yr... 3.01, 3.03, 3.05
----- S -----
SE PART OF SITE PRE... 5.01, 5.02,
5.03, 5.04, 5.05, 5.06, 5.07,
5.08
----- W -----
Watershed... 1.01, 1.02
A-1
AREA C APPENDIX D
Page 16 of 16
AREA D
Table o Contents
xxxxxxxxxxxxxxxxxxxxxx MASTER SUMMARY xxxxxxxx*xxx-rxxxxxxxx
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
xxxxxxxxxxxxxxxxxxxxxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ........................ 2.01
2 year Gastonia 2 Yr I-D-F Table 2.02
25 Year Gastonia 25 Yr I-D-F Table ........................ 2.03
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING x xxxxxxxxxxxxxxxxxxxxxx
DIRECT CONNECT.. 2 Yr Node: Addition Summary 3.01
DIRECT CONNECT. 10 Yr Node: Addition Summary ............. 3,03
DIRECT CONNECT..25 Yr Node: Addition Summary ............. 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING xxxxxxxxxxxxxxxxxxxxxxx
SITE IN 2 Yr Node: Pond Inflow Summary .......... 4.01
SITE IN 10 Yr Node: Pond Inflow Summary ...... .... 4.03
SITE IN 25 Yr Node: Pond Inflow Summary ........ .... 4.05
xxxxxxxxxxxxxxxx xx RATIONAL METHOD CALCS xxxxxxx*xxxxxxxxxxx
AREA D ....... PRE C and Area ........ ............. 5.01
AREA D ....... 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Hyg ..... ............. 5.03
AREA D ....... POST C and Area ....... ............. 5.04
AREA D ....... 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational Hyg ..... ............. 5.06
AREA D ....... 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod,. Rational Hyg ..... ............. 5.08
AREA D
APPENDIX E
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxxxxxxxxxxxxxx***xxxxxxx
xxxxxxxxxxxxxxx*xxxxxxxxxx xlx xx x-txxxxxxx*xxxxx***xx*:rxx*xxxxx**xxxxx::tx**
x x
x x
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For A11 Storm Frequencies ----
x *
x x
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxxxxxxxxxxxxxxxxxxx**xxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*:txxxxxxxxxxxxxxxxx
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)

................ Area =
......... 1.470 acres
............
....... Tc
............... = .0833
....... hrs
...........
................ ......... ............ ...... ............... ..................
VOLUMES
Freq. Adjusted Duration I Qpeak Allowable) Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
------------ cfs
------- cfs I
---------- --- ac-ft
------- ac-ft
-----
2 .850 .3667 3.2093 4.04 2.02 .123 .063
10 .850 .4167 4.0400 5.09 2.59 .175 .088
25 .850 .4167 4.4800 5.64 2.89 .194 .097
AREA D
APPENDIX E
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID
Gastonia
Rainfall
Return Event Type IDF ID
------------ --------------- ----------------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*Node=Outfall; +Node=Diversion;)
(True= 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

*DIRECT
CONNECT
JCT
2
.123 ---------
.0833 --------
4.04 -------- ------------
*DIRECT CONNECT JCT 10 .175 .0833 5.09
*DIRECT CONNECT JCT 25 .194 .0833 5.64
SITE IN POND 2 .123 .0833 4.04
SITE IN POND 10 .175 .0833 5.09
SITE IN POND 25 .194 .0833 5.64
SITE OUT POND 2 .123 .0833 4.04
SITE OUT POND 10 .175 .0833 5.09
SITE OUT POND 25 .194 .0833 5.64
AREA D AREA 2 .123 .0833 4.04
AREA D AREA 10 .175 .0833 5.09
AREA D AREA 25 .194 .0833 5.64
AREA D APPENDIX E
Page 3 of 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
-----------
.0833 7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -------
.0833 6.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA D
APPENDIX E
j
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... DIRECT CONNECT Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: DIRECT CONNECT
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID "HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 2 Yr
INFLOWS TO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS 2 Yr .123 .0833 4.04
TOTAL FLOW INTO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
- DIRECT CONNECT 2 Yr .123 .0833 4.04
Type.... Node: Addition Summary Page 3.02
Name.... DIRECT CONNECT Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = DIRECT CONNECT
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.04 cfs
Time to Peak = .0833 hrs
HYG Volume = .123 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (Cfs)
Time Output Time increment = .0633 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 I .00 4.04 4.04 4.04 4.04
.4165 1.62 .00
AREA D
APPENDIX E
Page 5 of 16 -
Type.... Node: Addition Summary Page 3.03
Name.... DIRECT CONNECT Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: DIRECT CONNECT
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
--------------------------------------------------------------------------
INLETS SITE IN INLETS 10 Yr
INFLOWS TO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS 10 Yr .175 .0833 5.09
TOTAL FLOW INTO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
DIRECT CONNECT 10 Yr .175 .0833 5.09
Type.... Node: Addition Summary Page 3.04
Name.... DIRECT CONNECT Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = DIRECT CONNECT
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .175 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 5.09 5.09 5.09 5.09
.4165 1 5.09 .01 .00
AREA D
APPENDIX E
Page 6 of 16
Type.... Node: Addition Summary Page 3.05
Name.... DIRECT CONNECT Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: DIRECT CONNECT
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 25 Yr
INFLOWS TO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS 25 Yr .194 .0833 5.64
TOTAL FLOW INTO: DIRECT CONNECT
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
---------------------------------------------------------------------------
DIRECT CONNECT 25 Yr .194 .0833 5.64
Type.... Node: Addition Summary Page 3.06
Name.... DIRECT CONNECT Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = DIRECT CONNECT
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 5.64 cfs
Time to Peak = .0833 hrs
HYG Volume = .194 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
---------I-------------------------------------------------------------
.0000 l .00 5.64 5.64 5.64 5.64
.4165 I 5.64 .01 .00
AREA D
APPENDIX E
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mail Pondpack\Rational - 3 set of calc's\
-------------------------------------------------------------------------
-----------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 THRU ROAD THRU ROAD 2 Yr
------------------------------------------------------------------------
--------------------------------------------------------------------------
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
THRU ROAD 2 Yr .123 .0833 4.04
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
SITE IN 2 Yr .123 .0833 4.04
Type.... Node: Pond Inflow Summary Page 4.02
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.04 cfs
Time to Peak = .0833 hrs
HYG Volume = .123 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 I .00 4.04 4.04 4.04 4.04
.4165 I 1.62 .00
AREA D
APPENDIX E
Page 8 of 16 "
Type.... Node: Pond Inflow Summary Page 4.03
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall.Pondpack\Rational - 3 set of calc's\THRU ROAD RATION_AL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
------------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 THRU ROAD THRU ROAD 10 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
THRU ROAD 10 Yr .175 .0833 5.09
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
SITE IN 10 Yr .175 .0833 5.09
Type.... Node: Pond Inflow Summary Page 4.04
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .175 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 1 .00 5.09 5.09 5.09 5.09
.4165 1 5.09 .01 .00
AREA D
APPENDIX E
Page 9 of 16
Type.... Node: Pond Inflow'Summary Page 4.05
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory; C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINR 20 THRU ROAD THRU ROAD 25 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
THRU ROAD 25 Yr .194 .0833 5.64
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SITE IN 25 Yr .194 .0833 5.64
Type.... Node: Pond Inflow Summary Page 4.06
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 5.64 cfs
Time to Peak = .0833 hrs
HYG Volume = .194 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I-----------------
--------------------------------------------
.0000 .00 5.64 5.64 5.64 5.64
.4165 I 5.64 .01 .00
AREA D
APPENDIX E
Page 10 of 16
Type.... C and Area Page 5.01
Name.... THRII ROAD Tag: PRE.
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRII ROAD RATIONAL.PPW
RATIONAL C COEFFICIENT.DATA
Area C x Area
Soil/Surface
------------ Description
--------------- C acres acres

Predeveloped -----
Condition -------- ----------
.2500 1.470 ----------
.368
WEIGHTED C & TOTAL AREA ---> .2500 1.470 .368
AREA D APPENDIX E
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... THRU ROAD Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .0962 hrs
.-----------------------------.
Tag Freq C C adj 1 C I Area 1 Peak Q
(years) factor 1 final in/hr acres 1 cfs
----- ------ ----- ------ I-----------------------------I ---=------
2 Yr 2 .250 1.000 1 .250 5.4550 1.470 2.02
------------------------------
Type.... Mod. Rational Hyg Page 5.03
Name.... THRU ROAD Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of ca7.c's\
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Td = .3667 hrs
-----------------------------
Tag Freq C C adj 1 C I Area 1 Peak Q
(years) factor 1 final in/hr acres 1 cfs
----- ------ ----- ------ I-----------------------------I ----------
2 Yr 2 .850 1.000 .850 3.2093 1.470 1 4.04
-----------------------------
HYG file =
HYG ID = THRU ROAD
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 4.04 cfs
Time to Peak = .0833 hrs
HYG Volume = .123 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------i----------------------------------------------
.0000 1 .00 4.04 4.04 4.04 4.04
AREA D APPENDIX E
Page 12 of 16
.4165 1.62 .00
Type.... C and Area Page 5.04
Name.... THRII ROAD Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRII ROAD RATIONAL.PPW
RATIONAL C COEFFICIENT DATA
-------------------------------------------------------------------------
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Private Roadway .8500 1.470 1.250
WEIGHTED C & TOTAL AREA ---> .8500 1.470 1.250
.........................................................................
j
AREA D
APPENDIX E
Page 13 d 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... THRU ROAD Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .0962 hrs
------------_-----------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .250 1.000 I .250 6.9780 1.470 I 2.59
-----------------------------
Type.... Mod. Rational Hyg Page 5.06
Name.... THRU ROAD Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Td = .4167 hrs
-----------------------------
Tag Freq C C adj C I Area I Peak Q
(years) factor final in/hr acres I cfs
----- ------ ----- ------ I------------------------------I --------
10 Yr 10 .850 1.000 I .850 4.0400 1.470 5.09
-----------------------------
HYG file =
HYG ID = THRU ROAD
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 5.09 cfs
Time to Peak = .0833 hrs
HYG Volume = .175 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I--------------------------------------------------------------
.0000 I .00 5.09 5.09 5.09 5.09
.4165 5.09 .01 .00
AREA D
APPENDIX E
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... THRU ROAD Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\THRU ROAD RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .0962 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I-----------------------------I ----------
25 Yr 25 .250 1.000 .250 7.7902 1.470 I 2.89
-----------------------------
Type.... Mod. Rational Hyg Page 5.08
Name.... THRU ROAD Tag: 25 Yr Event: 25 yr
File..... C:\Gaston Mall Pondpack\Rational - 3 set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Td = .4167 hrs
-----------------------------
Tag Freq C C adj I C I Area Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
25 Yr 25 .850 1.000 I .850 4.4800 1.470 I 5.64
-----------------------------
HYG file =
HYG ID = THRU ROAD
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 5.64 cfs
Time to Peak = .0833 hrs
HYG Volume = .194 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I-------------------------- 7--------------------------
.0000 I .00 5.64 5.64 5.64 5.64
.4165 I 5.64 .01 .00
AREA D
APPENDIX E
Page 15 of 16
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- D -----
DIRECT CONNECT 2 Yr... 3.01, 3.03,
3.05
----- S SITE IN 2 Yr... 4.01, 4.03,
4.05
----- T -----
THRU ROAD PRE... 5.01, 5.02, 5.03,
5.04, 5.05, 5.06, 5.07, 5.08
----- W -----
Watershed... 1.01, 1.02
A-1

AREA D
APPENDIX E
Page 16 of 16
AREA E
Table of Contents
xxxxxxxxxxxxxxxxxxxxxx MASTER SUMMARY xxxxxxxxxxxxxxxxxxx*xx
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
xxxxxxxxxxxxxxxxxxxtxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxx**
10 Year Gastonia 10 Yr I-D-F Table .................. 2.01
2 year Gastonia 2 Yr I-D-F Table .................. 2.02
25 Year Gastonia 25 Yr I-D-F Table .................. 2.03
xxxxxxx+xxxxxtxxxxxxxxx HYG ADDITION xxxxxxxxxxxxxxxxxxxxxxx
CONTROLLED...... 2 Yr Node: Addition Summary ....... 3.01
CONTROLLED...... 10 Yr Node: Addition Summary ....... 3.03
CONTROLLED...... 25 Yr Node: Addition Summary ....... 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING xxxxxxxxxxxxxxxxxxxxxxx
BIO-RETENTIONIN 2 Yr Node: Pond Inflow Summary .... 4.01
BIO-RETENTIONIN 10 Yr Node: Pond Inflow Summary .... 4.03
BIO-RETENTIONIN 25 Yr Node: Pond Inflow Summary .... 4.05
xxxxxkxxxxxxxxxxxx RATIONAL METHOD CALCS xxxxxxx*:xxxxxxxxxx
RETAIL 1/BIORETENT PRE C and Area ................... 5.01
RETAIL 1/BIORETENT 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Graph ................ 5.03
RETAIL 1/BIORETENT POST
C and Area ......................... 5.04
RETAIL 1/BIORETENT 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational.Graph .. .............. 5.06
RETAIL 1/BIORETENT 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Graph .. .............. 5.08
AREA E APPENDIX F
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mail Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
* *
* x
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
* *
x *
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Area = 4.670 acres Tc = .0833 hrs
VOLUMES
Freq. Adjusted Duration I Qpeak Allowablel Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
----
-- cfs cfs I ac-ft ac-ft

2 .817
.3500 ---
---
3.2880 ------
12.64 ----------- I---
6.42 l -------
.366 -----------
.185
10 .817 .4000 4.1240 15.86 8.21 l .524 .259
25 .817 .4000 4.5720 17.58 9.17 .581 .285
AREA E APPENDIX F
Page 2 d 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
MASTER DESIGN STORM SUMMARY
Default Network De sign Storm File, ID Gastonia
Rainfall
Return Event
------------ Type IDF ID
--------------- --------
--------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Net work
( *Node=Outfall; +Node=Diversi on;)
(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
-------- ------------
BIO-RETENTIONIN POND 2 .365 .0900 12.64
BIO-RETENTIONIN POND 10 .524 .0900 15.85
BIO-RETENTIONIN POND 25 .581 .0900 17.58
BIO-RETENTIONOUT POND 2 .000 .0100 .00 703.97 .365
BID-RETENTIONOUT POND 10 .146 .3900 15.84 704.04 .395
BIO-RETENTIONOUT POND 25 .203 .3800 17.58 704.05 .396
*CONTROLLED JCT 2 .000 .0100 .00
*CONTROLLED JCT 10 .146 .3900 15.84
*CONTROLLED JCT 25 .203 .3800 17.58
TARGET/BIORETENT AREA 2 .365 L .0933 12.64
TARGET/BIORETENT AREA 10 .524 L .0933 15.86
TARGET/BIORETENT AREA 25 .581 L .0933 17.56
AREA E APPENDIX F
Page 3 of 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
------- intens., in/hr
----
.0833 -----------
7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
------- Intens., in/hr
----
.0833 -----------
5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
---- intens., in/hr
-------
.0833 -----------
8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA E APPENDIX F
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... CONTROLLED Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG
---------------------------------------- file
---------- HYG ID
------ HYG tag

INLETS BIO-RETENTIONIN -----
INLETS -------------
2 Yr
INFLOWS TO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
------ hrs cfs

INLETS 2 Yr ---
.000 -----------
.0100 -------------
.00
TOTAL FLOW INTO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
----- hrs cfs

CONTROLLED 2 Yr -----
.000 ----------
.0100 -------------
.00
Type.... Node: Addition Summary Page 3.02
Name.... CONTROLLED Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 2 Yr
-----------------------------------
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0100 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 .00 .00
AREA E APPENDIX F
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... CONTROLLED Event: 10 yr
File..,. C:\Gaston Mall Pondpack\Rational - 4th se t of calc's\ RETAIL 1 BIORETENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID
----------- HYG to
-

INLETS BIO-RETENTIONIN
INLETS ------------
10 Yr
INFLOWS TO: CONTROLLED
----------------------- ----------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
---
- hrs cfs

INLETS 10 Yr -
---
.146 ------------
.3900 -------------
15.84
TOTAL FLOW INTO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
---
- hrs cfs

CONTROLLED 10 Yr -
---
.146 ------------
.3900 -------------
15.84
Type.... Node: Addition Summary Page 3.04
Name.... CONTROLLED Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\ RETAIL 1 B_IORE_TENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 10 Yr
---
-
-
-------------------
Peak Discharge = -----------
15.84 cfs
Time to Peak = .3900 hrs
HYG Volume =
------------------------ .146 ac-ft
-----------
HYDROGRAPH ORDINATES (cfs)
Time I Output Tim e increment = .0100 hrs
hrs
------I Time on left represen
----------------------- ts time for first value in each row.

.3300 I --
.00 7.02 -----------
12.85 ---------------
14.99 ---
15.62
.3800 15.79 15.84 15.70 14.97 13.56
.4300 I 11.84 10.05 8.26 6.48 4.75
.4800 I 3.07 1.77 1.05 .67 .46
.5300 I ,33 .24 .18 .14 .11
.5800 I .09 .08 .06 .05 .04
.6300 I .04 .04 .03 .03 .03
.6800 I .02 .02 .02 .02 .01
.7300 I .01 .01 .01 .01 .01
.7800 I .01 .01 .01 .01 .00
.8300 I .00 ,00 .00 .00
AREA E APPENDIX F
Page 6 of 16
Type.... Node: Addition Summary Page 3.05
Name.... CONTROLLED Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\ RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
--------------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS BIO-RETENTIONIN INLETS 25 Yr
INFLOWS TO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS 25 Yr .203 .3800 17.58
TOTAL FLOW INTO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
CONTROLLED 25 Yr .203 .3800 17.58
Type.... Node: Addition Summary Page 3.06
Name.... CONTROLLED Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\ RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 17.58 cfs
Time to Peak = .3800 hrs
HYG Volume = .203 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0100 hrs
hrs I
---------
- Time on
----------- left represents
-------------- time for first value in each row.
I
.3000
.00 -
6.19 ---------
13.68 ---------------
16.51 -----------
17.30
.3500 17.51 17.56 17.57 17.58 17.58
.4000 17.40 16.58 14.99 13.07 11.08
.4500 I 9.09 7.12 5.19 3.33 1.90
.5000 I 1.11 .71 .48 .34 .25
.5500 I .19 .15 .12 .10 .08
.6000 I .06 .05 .05 .04 .04
.6500 I .03 .03 .03 .02 .02
.7000 I .02 .02 .01 .01 .01
.7500 I .01 .01 .01 .01 .01
.8000 .01 .01 .00 .00 .00
.8500 .00 .00
AREA E APPENDIX F
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... BIO-RETENTIONIN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\ RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: BIO-RETENTIONIN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
WARNING: Adding in hydrograph that is truncated on left...
WARNING: Missed peak when adding hydrograph...
ADDLINK 20 TARGET/BIORETENT TARGET/BIORETENT2 Yr
INFLOWS TO: BIO-RETENTIONIN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
TARGET/BIORETENT 2 Yr .365 .0933 12.64
TOTAL FLOW INTO: BIO-RETENTIONIN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
BIO-RETENTIONIN 2 Yr .365 .0900 12.64
Type.... Node: Pond Inflow Summary Page 4.02
Name.... BIO-RETENTIONIN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = 310-RETENTIONIN
HYG Tag = 2 Yr
-----------
------------------
Peak Discharge = 12.64 ------
cfs
Time to Peak = .0900 hrs
HYG Volume = .365
----------------------------- ac-ft
------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0100 hrs
hrs
------ I Time on left represents time for
--------------
---- first value in each row.

.0000 1 -
------------
.00 1.52 -----
3.03 ----------------
4.55 -------
6.07
.0500 7.59 9.10 10.62 12.14 12.64
.1000 1 12.64 12.64 12.64 12.64 12.64
.1500 1 12.64 12.64 12.64 12.64 12.64
.2000 12.64 12.64 12.64 12.64 12.64
.2500 1 12.64 12.64 12.64 12.64 12.64
.3000 1 12.64 12.64 12.64 12.64 12.64
.3500 1 12.31 11.12 9.61 8.09 6.57
.4000 1 5.06 3.54 2.02 Si . .00
AREA E APPENDIX F
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... BIO-RETENTIONIN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: BIO-RETENTIONIN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
--------------------------------------------------------------------------
ADDLINK 20 TARGET/BIORETENT TARGET/BIORETENT10 Yr
INFLOWS TO: BIO-RETENTIONIN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
TARGET/BIORETENT 10 Yr .524 .0933 15.86
TOTAL FLOW INTO: BIO-RETENTIONIN
---------------------------------------- Volume Peak_ Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
BIO-RETENTIONIN 10 Yr .524 .0900 15.85
Type.... Node: Pond Inflow Summary Page 4.04
Name.... BIO-RETENTIONIN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = BIO-RETENTIONIN
HYG Tag = 10
----------- Yr
---
Peak Discharge ----------------
= 15.85 -----
cfs
Time to Peak = .0900 hrs
HYG Volume
-------------- = .524
---------------- ac-ft
-----
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0100 hrs
hrs
---------I Time on lef
--------------- t represents time for
--------------- first value in each row.

.0000
.00 -
1.90 -----
3.81 ----------------
5.71 ----------
7.61
.0500 9.51 11.42 13.32 15.22 15.85
.1000 15.86 15.86 15.86 15.86 15.86
.1500 15.86 15.86 15.86 15.86 15.86
.2000 15.86 15.86 15.86 15.86 15.86
.2500 15.86 15.86 15.86 15.86 15.86
.3000 15.86 15.86 15.86 15.86 15.86
.3500 15.86 15.86 15.86 15.86 15.86
.4000 15.44 13.95 12.05 10.15 8.24
.4500 6.34 4.44 2.54 .63 .00
AREA E APPENDIX F
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... BIO-RETENTIONIN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: BIO-RETENTIONIN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 TARGET/BIORETENT TARGET/BIORETENT25 Yr
INFLOWS TO: BIO-RETENTIONIN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
TARGET/BIORETENT 25 Yr .581 .0933 17.58
TOTAL FLOW INTO: BIO-RETENTIONIN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
BIO-RETENTIONIN 25 Yr .581 .0900 17.58
Type.... Node: Pond Inflow Summary Page 4.06
Name.... BIO-RETENTIONIN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = BIO-RETENTIONIN
HYG Tag = 25 Yr
---------------
--------------
Peak Discharge = 17.58 ------
cfs
Time to Peak = .0900 hrs
HYG Volume = .581
----------------------------- ac-ft
------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0100 hrs
hrs
------ I Time on left represents time for
----------------------------- first value in each row.

.0000 1 -
.00 2.11 ------
4.22 ----------------
6.33 ---------
8.44
.0500 10.55 12.66 14.77 16.88 17.58
.1000 1 17.58 17.58 17.58 17.58 17.58
.1500 17.58 17.58 17.58 17.58 17.58
.2000 1 17.58 17.58 17.58 17.58 17.58
.2500 17.58 17.58 17.58 17.58 17.58
.3000 1 17.58 17.58 17.58 17.58 17.58
.3500 I 17.58 17.58 17.58 17.58 17.58
.4000 1 17.11 15.47 13.36 11.25 9.14
.4500 I 7.03 4.92 2.81 .70 .00
AREA E APPENDIX F
Page 10 of 16 "
Type.... C and Area Page 5.01
Name.... TARGET/BIORETENT Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
RATIONAL C COEFFICIENT DATA
-------------------------------------------------------------------------
Area C x Area
Soil/Surface
------------- Description C
-------------- acres acres

Predeveloped ----- --------
Portion of the site .2500 ----------
4.670 ----------
1.168
WEIGHTED C & TOTAL AREA ---> .2500 4.670 1.168
AREA E APPENDIX F
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... TARGET/BIORETENT Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .0962 hrs
.-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- - ----- ------ i-------------
2 Yr 2 .250 1.000 I .250 5.4546 4.670 6.42
-----------------------------
Type.... Mod. Rational Graph Page 5.03
.Name.... TARGET/BIORETENT Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 2 yr I Allowable Outflow: 6.42 cfs
* 'C' Adjustment: 1.000 Required Storage: .185 ac-ft
*--------------------------------------------------------------------*
* Peak Inflow: 12.64 cfs
* HYG File: 2 Yr
**********************************************************************
Q I Td = .3500 hrs I Return Freq: 2 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I i
I I
Tc= .0833 hrs
I I = 5.6396 in/hr I Area = 4.670 acres
Q = 21.68 cfs I Weighted C = .817
I Adjusted C = .817
I I 1
I Required Storage
-- .185 ac-ft I Td= .3500 hrs
I I I = 3.2880 in/hr
I x x x x x x x I x x x x x x x x x x x Q= 12.64 cfs
l I
I x x
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 6.42 cfs
x o Ix (Allow.Outflow)
i o i 1
I x o NOT TO SCALE I x
°
o I x
------------------------ I ----------------------------- I ------------
.1420 hrs .3910 hrs T
AREA E APPENDIX F
Page 12 of 16
Type.... C and Area Page 5.04
Name.... TARGET/BIORETENT Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Primary Development .9000 4.070 3.663
Bio-retention .2500 .600 .150
WEIGHTED C & TOTAL AREA ---> .8165 4.670 3.813
.........................................................................
.........................................................................
AREA E APPENDIX F
Page 13 of 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... TARGET/BIORETENT Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .0962 hrs
-----------------------------
Tag Freq C C adj I C I Area 1 Peak Q
(years) factor 1 final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .250 1.000 1 .250 6.9776 4.670 I 8.21
-----------------------------
Type.... Mod. Rational Graph Page 5.06
Name.... TARGET/BIORETENT Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Q
* RETURN FREQUENCY: 10 yr Allowable Outflow: 8.21 cfs
* 'C' Adjustment: 1.000 Required Storage: .259 ac ft
*---------------------------------------------------------------------*
* Peak Inflow: 15.86 cfs
* HYG File: 10 Yr
Td = .4000 hrs 1 Return Freq: 10 yr
- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I .
I
I x
I •
I X O
I o
I o
AREA E
I
I
Tc= .0833 hrs
I = 7.1995 in/hr I Area = 4.670 acres
Q = 27.68 cfs i Weighted C = .817
I• 1 Adjusted C = .817
. I I
I Required Storage
-- .259 ac-ft Td= .4000 hrs
I I I = 4.1240 in/hr
x x x x x x xlx x x x x x x x x x x Q= 15.86 cfs
i
x x
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 8.21 cfs
0 I• Ix (A11ow.Outflow)
0 1 1
I 'NOT TO SCALE I x
I
I I x
------------ I ----------------------------- I ------------
.1419 hrs .4402 hrs T
Page 14 of 16
APPENDIX F
Type.... Rational Predev. Peak Q Page 5.07
Name.... TARGET/BIORETENT Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .0962 hrs
-----------------------------
Tag Freq C C adj C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ----------------------------------- I --------
25 Yr 25 .250 1.000 I .250 7.7898 4.670 I 9.17
-----------------------------
Type.... Mod. Rational Graph Page 5.08
Name.... TARGET/BIORETENT Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\RETAIL 1 BIORETENTION.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 25 yr I Allowable Outflow: 9.17 cfs
* 'C' Adjustment: 1.000 Required Storage: .285 ac-ft
*--------------------------------------------------------------------*
* Peak Inflow: 17.58 cfs
* HYG File: 25 Yr
Q I Td = .4000 hrs I Return Freq: 25 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I I
I I
I Tc= .0833 hrs
I I = 8.0394 in/hr Area = 4.670 acres
Q = 30.91 cfs I Weighted C = .817
1• I Adjusted C = .817
I I I
I Required Storage I
-- .285 ac-ft I Td= .4000 hrs
I I I = 4.5720 in/hr
x x x x x x x l x x x x x x x x x x x Q= 17.58 cfs
I I
x x
o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o Q= 9.17 cfs
x o i. Ix (Allow.Outflow)
o I 1
x o NOT TO SCALE x
o 1
l o I x
------------------------ I------------------------------ I------------
.1419 hrs .4399 hrs T
AREA E APPENDIX F
Page 15 of 16
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- B -----
BIO-RETENTIONIN 2 Yr... 4.01, 4.03,
4.05
----- C -----
CONTROLLED 2 Yr... 3.01, 3.03, 3.05
------ T -----
TARGET/BIORETENT PRE... 5.01, 5.02,
5.03, 5.04, 5.05, 5.06, 5.07,
5.08
----- W -----
Watershed... 1.01, 1.02
A-1
AREA E APPENDIX F
Page 16 of 16
DU'HARTS CREEK A14-D CONTRIBUTING AREA
Table of Contents
f:
xxxx+*xxxxxxxxxxxxxxxx MASTER SUMMARY xxxxxxxx*xxxxxxxxxxxxx
watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
xxxxxxxxxi-xxxxxxxxxxxx RAINFALL DATA *xxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ........................ 2.01
2 year Gastonia 2 Yr I-D-F Table ........................ 2.02
25 Year Gastonia 25 Yr I-D-F Table ........................ 2.03
xxxxxxxxxxxxxxxxxxxxxxx HYG ADDITION xxxxxxxxxxxxxxxxxxxxxxx
CREEK........... 2 Yr Node: Addition Summary ............. 3.01
CREEK........... 10 Yr Node: Addition Summary ............. 3.03
CREEK........... 25 Yr Node: Addition Summary ............. 3.05
xx*xxxi:xxxxxxxxxxxxxxxx POND ROUTING **xxxxxxxxxxxxxxxxxxxxx
SITE IN 2 Yr Node: Pond Inflow Summarv .......... 4.01
SITE IN 10 Yr Node: Pond Inflow Summary .......... 4.03
SITE IN 25 Yr Node: Pond Inflow Summary 4.05
xxxxx*x-,:xxxxxxxxxx RATIONAL METHOD CALCS xxx*x*:x*x*xx*x++
CREEK........... PRE
C and Area ......................... 5.01
CREEK........... 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Hyg .... .............. 5.03
CREEK........... POST
C and Area ........... .............. 5.04
CREEK........... 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational Hyg .................. 5.06
CREEK........... 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Hyg .................. 5.08
AREA F APPENDIX G
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREER RATIONAL.PPW
* *
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
*
* *
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)

................ Area =
......... 9.120 acres
...........
....... Tc
............... = .0833
....... hrs
...........
................ ......... ........... ....... ............... ..................
VOLUMES
Freq. Adjusted Duration. I Qpeak Allowable) Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
----------- cfs
------- cfs I
- ac-ft ac-ft
2 .271 .0833 5.6400 14.08 12.11 .097 .014
10 .271 .0833 7.2000 17.97 15.61 .124 .016
25 .271 .0833 8.0400 20.07 17.41 .138 .018
AREA F APPENDIX G
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mail Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID
Return Event
------------
2 Yr
10 Yr
25 Yr
Rainfall
Type
I-D-F Curve
I-D-F Curve
I-D-F Curve
Gastonia
IDF ID
----------------
2 year Gastonia
10 Year Gastonia
25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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

CREEK -
AREA
2 -
.097 --
------
.0833 -------- -------- ------------
14.08
CREEK AURA 10 .124 .0833 17.97
CREEK AREA 25 .138 .0833 20.07
*CREEK JCT 2 .097 .0833 14.08
*CREEK JCT 10 .124 .0833 17.97
*CREEK JCT 25 .138 .0833 20.07
SITE IN POND 2 .097 .0833 14.08
SITE IN POND 10 .124 .0833 17.97
SITE IN POND 25 .138 .0833 20.07
SITE OUT POND 2 .097 .0833 14.08
SITE OUT POND 10 .124 .0833 17.97
SITE OUT POND 25 .138 .0833 20.07
AREA F APPENDIX G
Page 3 of 16
Type.... I-D-F Table Page 2.01.
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
-------

.0833 ----
7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 5.6400
1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
---------- intens., in/hr
-
.0833 -----------
8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA F APPENDIX G
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... CREEK Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CREEK
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 2 Yr
INFLOWS TO: CREEK
-------- -------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
--------------------------------------
- ac-ft
- hrs cfs
-
INLETS 2 Yr -----------
.097 ---------
.0833 -------------
14.08
TOTAL FLOW INTO: CREEK
-------- -------------------------------- Volume Peak Time Peak Flow
HYG file
-------- HYG ID HYG tag
-------------------------------- ac-ft
---------- hrs cfs

CREEK 2 Yr --
.097 ---------
.0833 -------------
14.08
Type.... Node: Addition Summary Page 3.02
Name.... CREEK Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set o f calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CREEK
HYG Tag = 2 Yr
-------------
-----------------
Peak Discharge = 14.08 -----
cfs
Time to Peak = .0833 hrs
HYG Volume = .097
------------------------------ ac-ft
-----
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .08 33 hrs
hrs
-------- I Time on left represents time for first
-
------------------------- value in each row.

.0000 I
------
I .00 14.08 -----------
.00 ---------- ----------
AREA F APPENDIX G
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... CREEK Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CREEK
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
---=--------------------------------------------------------------------
------------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 10 Yr
INFLOWS TO: CREEK
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
------------------------------------------------------------------------
INLETS 10 Yr .124 .0833 17.97
TOTAL FLOW INTO: CREEK
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
CREEK 10 Yr .124 .0833 17.97
Type.... Node: Addition Summary Page 3.04
Name.... CREEK Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CREEK
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 17.97 cfs
Time to Peak = .0833 hrs
HYG Volume = 124 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I-------------------------------------------------------------
.0000 1 .00 17.97 .00
AREA F APPENDIX G
Page 6 of 1.6
Type.... Node: Addition Summary Page 3.05
Name.... CREEK Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CREEK
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
-----------------------------------------------------------------------
-------------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
INLETS SITE IN INLETS 25 Yr
INFLOWS TO: CREEK
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS 25 Yr .138 .0833 20.07 .
TOTAL FLOW INTO: CREEK
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs As
-------------------------------------------------------------------------
CREEK ' 25 Yr .138 .0833 20.07
Type.... Node: Addition Summary Page 3.06
Name.... CREEK Event: 25 yr
File.... Q \Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONA'L.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CREEK
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 20.07 cfs
Time to Peak = .0833 hrs
HYG Volume = .138 ac-ft
-----------------------------.------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row,
------ I-------------------------------------------------------------
.0000 1 .00 20.07 .00
AREA F APPENDIX G
Page 7 016
Type.... Node: Pond Inflow Summary Page 4.01
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
--------------------------------------------------------------------------
ADDLINK 20 CREEK CREEK 2 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
CREEK 2 Yr .097 .0833 14.08
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HY"G file HYG ID HYG tag ac-ft hrs cf.s
--------------------------------------------------------------------------
SITE IN 2 Yr .097 .0833 14.08
Type.... Node: Pond Inflow Summary Page 4.02
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack.\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file -
HYG ID = SITE IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 14.08 cfs
Time to Peak = .0833 hrs
HYG Volume = .097 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 .00 14.08 .00
AREA F APPENDIX G
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 CREEK CREEK 10 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
CREEK 10 Yr .124 .0833 17.97
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SITE IN 10 Yr .124 .0833 17.97
Type.... Node: Pond Inflow Summary Page 4.04
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 17.97 cfs
Time to Peak = .0833 hrs
HYG Volume = .124 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I-------------------------------------------------------------
.0000 1 .00 17.97 .00
AREA F APPENDIX G
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 CREEK CREEK 25 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
CREEK 25 Yr .138 .0833 20.07
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SITE IN 25 Yr .138 .0833 20.07
Type.... Node: Pond Inflow Summary Page 4.06
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 20.07 cfs
Time to Peak = .0833 hrs
HYG Volume = .138 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I--------------------------------------------------------------
.0000 1 .00 20.07 .00
AREA F APPENDIX G ?y
Page 10 of 16
Type.... C and Area Page 5.01
Name.... CREEK Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational 4th set of calc's\CREEK RATIONAL.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Duharts Creek - Contributing .2500 8.860 2.215
Duharts Creek - Creek Line 1.0000 .260 .260
WEIGHTED C & TOTAL AREA ---> .2714 9.120 2.475
.......................................................................
.......................................................................
AREA F APPENDIX G
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... CREEK Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 vear Gastonia
Tc = .1382 hrs
-----------------------------
Tag Freq C C adj I C I Area Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
2 Yr 2 .271 1.000 .271 4.8531 9.120 I 12.11
-----------------------------
Type.... Mod. Rational Graph Page 5.03
Name.... CREEK Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 2 yr I Allowable Outflow: 12.11 cfs
* 'C' Adjustment: 1.000 I Required Storage: .014 ac-ft
* STORM DURATION = Tc for Max.Storage
*--------------------------------------------------------------------*
* Peak Inflow: 14.08 cfs
* HYG File: 2 Yr
Q I
Tc= .0833 hrs
I = 5.6400 in/hr Area = 9.120 acres
Q = 14.08 cfs Weighted C = .271
Adjusted C = .271
Required Storage
----------- .014 ac-ft
• I-
I .
• I •
0 0 o Q = 12.11 cfs
0 I. (A11ow.Outflow)
o I ,
0 I NOT TO SCALE
I
--------------------- -------------------------
.0949 hrs T
AREA F APPENDIX G
Page 12 of 16
Type.... C and Area Page 5.04
Name.... CREEK Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
RATIONAL C COEFFICIENT DATA
Area C x Area
Soil/Surface Description
---------------------------- C acres acres
----
Duharts Creek - Contributing --------
.2500 ----------
8.860 ----------
2.215
Duharts Creek - Creek Line 1.0000 .260 .260
WEIGHTED C & TOTAL AREA ---> .2714 9.120 2.475
AREA F APPENDIX G
Page 13 of 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... CREEK Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .1382 hrs
-----------------------------
Tag Freq C C adj C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------i ----------
10 Yr 10 .271 1.000 I .271 6.2557 9.120 I 15.61
-----------------------------
Type.... Mod. Rational Graph Page 5.06
Name.... CREEK Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 10 yr I Allowable Outflow: 15.61 cfs
* 'C' Adjustment: 1.000 I Required Storage: .016 ac-ft
* STORM DURATION - Tc for Max.Storage
*--------------------------------------------------------------------*
* Peak Inflow: 17.97 cfs
* HYG File: 10 Yr
**********************************************************************
Q
Tc= .0633 hrs
I = 7.2000 in/hr Area = 9.120 acres
Q = 17.97 cfs Weighted C = .271
Adjusted C = .271
Required Storage
----------- .016 ac-ft
I-
I
I
0 0 o Q = 15.61 cfs
0 (Allow.0utflow)
o I .
0 I NOT TO SCALE
D i
----------------------I------------------------
.0942 hrs T
AREA F APPENDIX G
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... CREEK Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25• Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .1382 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
25 Yr 25 .271 1.000 I .271 6.9776 9.120 I 17.41
-----------------------------
Type.... Mod. Rational Graph Page 5.08
Name.... CREEK Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\CREEK RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 25 yr I Allowable Outflow: 17.41 cfs
* 'C' Adjustment: 1.000 I. Required Storage: .018 ac-ft
* STORM DURATION = Tc for Max.Storage
*--------------------------------------------------------------------*
* Peak Inflow: 20.07 cfs
* HYG File: 25 Yr
Q I
Tc= .0833 hrs
I = 8.0400 in/hr Area = 9.120 acres
Q = 20.07 cfs Weighted C = .271
Adjusted C = .271
Required Storage
----------- -01B ac-ft
• I.
I .
i
0 0 o Q = 17.41 cfs
o I• (Allow.0utflow)
o I .
o NOT TO SCALE
0 i =________
> I
---------------------------.-------------------
.0943 hrs T
AREA F APPENDIX G
Page 15 of 16
Appendix A A-1
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- C -----
CREEK PRE... 5.01, 3.01, 5.02, 5.03,
5.04, 3.03, 5.05, 5.06, 3.05,
5.07, 5.08
----- S -----
SITE IN 2 Yr... 4.01, 4.03,
4.05
----- W -----
Watershed... 1.01, 1.02
AREA F APPENDIX G
Page 16 of 16
AREA G
Table of Contents
xxxxxxxxxxxxxxxxxxxxxx MASTER SUMMARY xxxx*xxxxxxxxxxxxxxxxx
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
xxxxxxxxxxxxxxxxx*xxxx RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ....................... 2.01
2 year Gastonia 2 Yr I-D-F Table ....................... 2.02
25 Year Gastonia 25 Yr I-D-F Table ....................... 2.03
xxxxxxxxxxxxxxxxxxxxxxx HYG ADDITION xxxxxxx:xxxxxxxxxxxxxxx
OUT 10.......... 2 Yr Node: Addition Summary ............. 3.01
OUT 10......... 10 Yr Node: Addition Summary ............. 3.03
OUT 10......... 25 Yr Node: Addition Summary ............. 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING xxxxxxxxxxxxxxxxxxxxxxx
INLETS IN 2 Yr Node: Pond Inflow Summary .......... 4.01
INLETS IN 10 Yr Node: Pond Inflow Summary ......... 4.03
INLETS IN 25 Yr Node: Pond Inflow Summary ......... 4.05
xxxxxxxxxxxxxxxxxx RATIONAL METHOD CALCS xxxxxxxxxxxxxxxxxxx
HARRIS TEETER... PRE
C and Area ......................... 5.01
HARRIS TEETER... 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Graph ................ 5.03
HARRIS TEETER... POST
C and Area ......................... 5.04
HARRIS TEETER... 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational Graph ................ 5.06
HARRIS TEETER... 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Graph 5.08
AREA G APPENDIX H
Page 1 of 16
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mail Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARRING.PPW
************************************************************************
* *
* *
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
* *
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)

................ Area =
......... 4.550 acres
............
...... Tc
............... = .0833
........ hrs
..........
................ ......... ............ ...... ............... ..................
VOLUMES
Freq. Adjusted Duration I Qpeak Allowablel Inflow Storage
years 'C'
---------------- hrs
--------- in/hr
-------- cfs cfs I ac-ft ac-ft
2 .900 .3667 3.2093 13.25 6.47 ; .402 .210
10 .900 .4167 4.0400 16.68 8.26 .574 .296
25 .900 .5833 3.7950 15.67 9.22 l .755 .321
AREA G APPENDIX H
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID Gastonia
Rainfall
Return Event Type IDF ID
------------ --------------- ----------------
2 Yr I-D-F Curve 2 year Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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

HARRIS
TEETER
AREA
2 ----------
.402
HARRIS TEETER AREA 10 .574
HARRIS TEETER AREA 25 .755
INLETS IN POND 2 .402
INLETS IN POND 10 .574
INLETS IN POND 25 .755
INLETS OUT POND 2 .402
INLETS OUT POND 10 .574
INLETS OUT POND 25 .755
*OUT 10 JCT 2 .402
*OUT 10 JCT 10 .574
*OUT 10 JCT 25 .755
Max
Qpeak Qpeak Max WSEL Pond Storage
hrs
------- cfs ft ac-ft
------

.0833 -- -------- -------------
13.25
.0833 16.68
.0833 15.67
.0833 13.25
.0833 16.68
.0833 15.67
.0833 13.25
.0833 16.68
.0833 15.67
.0833 13.25
.0833 16.68
.0833 15.67
AREA G APPENDIX H
Page 3 of 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs
----------- Intens., in/hr
---

.0833 --------
7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA G APPENDIX H
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
------------------------------------------------------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 2 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
DIRECT CONNECT 2 Yr .402 .0833 13.25
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 2 Yr .402 .0833 13.25
Type.... Node: Addition Summary Page 3.02
Name.... OUT 10 Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 13.25 cfs
Time to Peak .0833 hrs
HYG Volume = .402 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 .00 13.25 13.25 13.25 13.25
.4165 5.32 .00
AREA G APPENDIX H
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 10 Yr
INFLOWS TO: OUT 10
----------- ------ ------------ ---- ------ - Volume Peak Time Peak Flow
HYG file
----------- HYG
------ ID
------------ HYG
---- tag
------ ac-ft
---------- hrs cfs

DIRECT CONNECT
10
Yr -
.574 -------------
.0833 ----------
16.68
TOTAL FLOW INTO: OUT 10
----------- ------ ------------ ---- ------ - Volume Peak Time Peak Flow
HYG file
----------- HYG
------ ID
------------ HYG
----- tag
---- ac-ft hrs cfs

OUT
10
10 -
Yr -----------
.574 -------------
.0833 ----------
16.68
Type.... Node: Addition Summary Page 3.04
Name.... OUT 10 Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 16.68 cfs
Time to Peak = .0833 hrs
HYG Volume = .574 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I -------------------------------------------------------------
.0000 I .00 16.68 16.68 16.68 16.68
.4165 I 16.68 .03 .00
AREA G APPENDIX H
Page 6 of 16
Type.... Node: Addition Summary Page 3.05
Name.... OUT 10 Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: OUT 10
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
DIRECT CONNECT INLETS IN DIRECT CONNECT 25 Yr
INFLOWS TO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
DIRECT CONNECT 25 Yr .755 .0833 15.67
TOTAL FLOW INTO: OUT 10
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
OUT 10 25 Yr .755 .0833 15.67
Type.... Node: Addition Summary Page 3.06
Name.... OUT 10 Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = OUT 10
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 15.67 cfs
Time to Peak = .0833 hrs
HYG Volume = .755 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
-----------------------------------------------------------------------
.0000 .00 15.67 15.67 15.67 15.67
.4165 15.67 15.67 15.67 .04 .00
AREA G APPENDIX H
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... INLETS IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc`s\HARRIS TEETER AND PARKING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 HARRIS TEETER HARRIS TEETER 2 Yr
INFLOWS TO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
HARRIS TEETER 2 Yr .402 .0833 13.25
TOTAL FLOW INTO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS IN 2 Yr .402 .0833 13.25
Type.... Node: Pond Inflow Summary Page 4.02
Name.... INLETS IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 13.25 cfs
Time to Peak = .0833 hrs
HYG Volume = .402 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (Cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I-------------------------------------------------------------
.0000 I .00 13.25 13.25 13.25 13.25
.4165 I 5.32 .00
AREA G APPENDIX H
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... INLETS IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
--------------------------------------------------------------------------
ADDLINK 20 HARRIS TEETER HARRIS TEETER 10 Yr
INFLOWS TO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
HARRIS TEETER 10 Yr .574 .0833 16.68
TOTAL FLOW INTO: INLETS IN
----------------------------- ----------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
INLETS IN 10 Yr .574 .0833 16.68
Type.... Node: Pond Inflow Summary Page 4.04
Name.... INLETS IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of talc's\HARRIS TEETER AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 16.68 cfs
Time to Peak = .0833 hrs
HYG Volume = .574 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I --------------------------------------------------------------
.0000 .00 16.68 16.68 16.68 16.68
.4165 I 16.68 .03 .00
AREA G APPENDIX H
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... INLETS IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: INLETS IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG to
----------------------------------------------------- --------------------
ADDLINK 20 HARRIS TEETER HARRIS TEETER 25 Yr
INFLOWS TO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
HARRIS TEETER 25 Yr .755 .0833 15.67
TOTAL FLOW INTO: INLETS IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
INLETS IN 25 Yr .755 .0833 15.67
Type.... Node: Pond Inflow Summary Page 4.06
Name.... INLETS IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = INLETS IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 15.67 cfs
Time to Peak = .0833 hrs
HYG Volume = .755 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I----------------------------
.0000 .00 15.67 15.67 15.67 15.67
.4165 15.67 15.67 15.67 .04 .00
AREA G APPENDIX H
Page 10 of 16
Type.... C and Area Page 5.01
Name.... HARRIS TEETER Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND P.ARKING.PPW
RATIONAL C COEFFICIENT DATA
.........................................................................
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Developed portion at SE corner conn .2500 4.550 1.138
WEIGHTED C & TOTAL AREA ---> .2500 4.550 1.138
AREA G APPENDIX H
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... HARRIS TEETER Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING. PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
2 Yr 2 2 year Gastonia
Tc = .0833 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I-----------------------------i --=-------
2 Yr 2 .250 1.000 I .250 5.6400 4.550 I 6.47
-----------------------------
Type.... Mod. Rational Graph Page 5.03
Name.... HARRIS TEETER Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CIA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
**********************************************************************
* RETURN FREQUENCY: 2 yr Allowable Outflow: 6.47 cfs
* 'C' Adjustment: 1.000 I Required Storage: .210 ac-ft
*-----------------------------------------------=-------------------=*
* Peak Inflow: 13.25 cfs
* HYG File: 2 Yr x
Q I Td = .3667 hrs I Return Freq: 2 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I I
i I
I Tc= .0833 hrs
I I = 5.6400 in/hr I Area = 4.550 acres
Q = 23.29 cfs I Weighted C = .900
I I• I Adjusted C = .900
I I I
I I Required Storage
I -- .210 ac-ft I Td= .3667 hrs
I I I I = 3.2093 in/hr
I x x x x x x x l x x x x x x x x x x x Q= 13.25 cfs
I i
i x x
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 6.47 cfs
I x o I. Ix (Allow.Outflow)
I 0 I I
X o I NOT TO SCALE x
t o I I x
------------------------ I--------- =------------------- I------------
.1435 hrs .4093 hrs T
AREA G APPENDIX H
Page 12 of 16
Type.... C and Area Page 5.04
Name.... HARRIS TEETER Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
RATIONAL C COEFFICIENT DATA
Area C X Area
Soil/Surface Description C acres acres
-------------------------------- -------- ----------- ----------
Developed portion at SE corner conn .9000 4.550 4.095
WEIGHTED C & TOTAL AREA ---> .9000 4.550 4.095
AREA G APPENDIX H
Page 13 of 16
Type.... Rational Predev. Peak Q Page 5.05
Name.... HARRIS TEETER Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CIA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .0833 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .250 1.000 .250 7.2000 4.550 I 8.26
-----------------------------
Type.... Mod. Rational Graph Page 5.06
Name.... HARRIS TEETER Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER. AND PARKING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for. Maximum Required Storage ----
Method T
Q = CIA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
**********************************************************************
* RETURN FREQUENCY: 10 yr Allowable Outflow: 8.26 cfs
x 'C' Adjustment: 1.000 I Required Storage: .296 ac-ft
*--------------------------------------------------------------------*.
* Peak inflow: 16.68 cfs =
* HYG File: 10 Yr
Q I Td = .4167 hrs I Return Freq: 10 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I I
I i
I Tc= .0833 hrs
I I = 7.2000 in/hr I Area = 4.550 acres
Q = 29.73 cfs i Weighted C = .900
i• Adjusted C = .900
I I I
I Required Storage I
I -- .296 ac-ft I Td= .4167 hrs
I I I I = 4.0400 in/hr
I x x x x x x x i x x x x x x x x x x x Q= 16.68 cfs
i I
i x x
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 8.26 cfs
x 0 I• Ix (Allow.Outflow)
I o I 1
I x o I NOT TO SCALE x
I o i 1
I o I x
------------------------ I-----------------------------
.1435 hrs .4587 hrs T
AREA G APPENDIX H
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... HARRIS TEETER Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .0833 hrs
------------------.
Tag Freq C C adj C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I --------
25 Yr 25 .250 1.000 I .250 8.0400 4.550 I 9.22
-----------------------------
Type.... Mod. Rational Graph Page 5.08
Name.... HARRIS TEETER Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\HARRIS TEETER AND PARKING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 25 yr I Allowable Outflow: 9.22 cfs
* 'C' Adjustment: 1.000 Required Storage: .321 ac-ft
*--------------------------------------------------------------------*
* Peak Inflow: 15.67 cfs
* HYG File: 25 Yr
Q I Td = .5833 hrs I Return Freq: 25 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
i I
I I
I Tc= .0833 hrs 1
I = 8.0400 in/hr I Area = 4.550 acres
I Q = 33.20 cfs I Weighted C = .900
I• I Adjusted C = .900
I I I
I Required Storage
-- .321 ac-ft I Td= .5833 hrs
I I I I I= 3.7950 in/hr
x x x x x x x l x x x x x x x x x x x Q= 15.67 cfs
I i
x x
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o Q= 9.22 cfs
i x 0 I• Ix (Allow.Outflow)
o I 1
I x 0 I NOT TO SCALE X
I I x
------------------------i-----------------------------I------------
.1435 hrs .6176 hrs T
AREA G APPENDIX H
Page 15 of 16
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- H -----
HARRIS TEETER PRE... 5.01, 5.02,
5.03, 5.04, 5.05, 5.06, 5.07,
5.08
----- I -----
INLETS IN 2 Yr... 4.01, 4.03,
4.05
----- 0 -----
OUT 10 2 Yr... 3.01, 3.03, 3.05
----- W -----
Watershed... 1.01, 1.02
A-1
AREA G APPENDIX H
Page 16 of 16
PRIMARY SITE
Table of Contents
xxxxxxxxxxxxxxxxxxxxxx MASTER SUMMARY xxxxxxxxxxxxxxxxxxxxxx
Watershed....... Mod. Rational Grand Summary 1.01
Master Network Summary ............. 1.02
xxx****xxxx*xxx**xx**x RAINFALL DATA xxxxxxxxxxxxxxxxxxxxxxx
10 Year Gastonia 10 Yr I-D-F Table ........................ 2.01
2 year Gastonia 2 Yr I-D-F Table ........................ 2.02
25 Year Gastonia 25 Yr I-D-F Table ........................ 2.03
xxxxxxxxxxxxxxxxxx**xxx HYG ADDITION x*xx*xxxxx**xx.xxxxxxx*.*
CONTROLLED...... 2 Yr Node: Addition Summary ............. 3.01
CONTROLLED...... 10 Yr Node: Addition Summary ............. 3.03
CONTROLLED...... 25 Yr Node: Addition Summary ............. 3.05
xxxxxxxxxxxxxxxxxxxxxxx POND ROUTING xxxxxxxxxxxxxxxxxxxxxxx
SITE IN 2 Yr Node: Pond Inflow Summary .......... 4.01
SITE IN 10 Yr Node: Pond Inflow Summary .......... 4.03
SITE IN 25 Yr Node: Pond Inflow Summary .......... 4.05
****************** RATIONAL METHOD CALCS *******************
PRIMARY SITE.... PRE
C and Area ......................... 5.01
PRIMARY SITE.... 2 Yr
Rational Predev. Peak Q ............ 5.02
Mod. Rational Hyg .................. 5.03
PRIMARY SITE.... POST
C and Area ......................... 5.04
PRIMARY SITE.... 10 Yr
Rational Predev. Peak Q ............ 5.05
Mod. Rational Hyg .................. 5.06
PRIMARY SITE.... 25 Yr
Rational Predev. Peak Q ............ 5.07
Mod. Rational Hyg .................. 5.08
AREA H APPENDIX I
Page 1 of 16 -
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
* *
* *
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
* *
* *
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)

................ Area =
......... 15.910 acres
.................. Tc
............... = .0833
....... hrs
...........
................ ......... .......... ........ ............... ..................
VOLUMES
Freq. Adjusted Duration I Qpeak Allowable] Inflow Storage
years IV
---------------- hrs
--------- in/hr
---------- cfs
--------- cfs I
---------- --- ac-ft
------- ac-ft
-----------
2 .820 .1667 4.4448 58.47 41.87 I .805 .250
10 .820 .1667 5.7657 75.85 54.34 I 1.045 .323
25 .820 .1667 6.4265 84.54 60.27 I 1.164 .364
AREA H APPENDIX I
Page 2 of 16
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID
Rainfall
Return Event Type
------------ -----------
2 Yr I-D-F Curve
10 Yr I-D-F Curve
25 Yr I-D-F Curve
Gastonia
IDF ID
----------------
2 year Gastonia
10 Year Gastonia
25 Year Gastonia
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return BYG Vol Qpeak
Node ID
------------ Type Event ac-ft Trun hrs
-
*CONTROLLED ---- ----
JCT ------
2 ---------- --
.805 ---------
.1666
*CONTROLLED JCT 10 1.045 .1666
*CONTROLLED JCT 25 1.164 .1666
PRIMARY SITE AREA 2 .805 .1666
PRIMARY SITE AREA 10 1.045 .1666
PRIMARY SITE AREA 25 1.164 .1666
SITE IN POND 2 .805 .1666
SITE IN POND 10 1.045 .1666
SITE IN POND 25 1.164 .1666
SITE OUT POND 2 .805 .1666
SITE OUT POND 10 1.045 .1666
SITE OUT POND 25 1.164 .1666
Max
Qpeak Max WSEL Pond Storage
cfs ft ac-ft
------- -------- ------------
58.47
75.85
84.54
58.47
75.85
84.54
58.47
75.85
84.54
58.47
75.85
84.54
AREA H APPENDIX I
Page 3 of 16
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 5.6400
.1670 4.4400
.2500 3.7600
.5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
AREA H APPENDIX I
Page 4 of 16
Type.... Node: Addition Summary Page 3.01
Name.... CONTROLLED Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAP H ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG
---------------------------------------- file
---------- HYG ID
------- HYG tag

OUTLET SITE IN ----
OUTLET -------------
2 Yr
INFLOWS TO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
--- hrs cfs

OUTLET 2 Yr ------
.805 -----------
.1666 -------------
58.47
TOTAL FLOW INTO: CONTROLLED
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag
----------------------------------------- ac-ft
------- hrs cfs

CONTROLLED 2 Yr ---
.805 ----------
.1666 -------------
58.47
Type.... Node: Addition Summary Page 3.02
Name.... CONTROLLED Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 58.47 cfs
Time to Peak = .1666 hrs
HYG Volume = .805 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 58.45 58.47 .07 .00
AREA H APPENDIX I
Page 5 of 16
Type.... Node: Addition Summary Page 3.03
Name.... CONTROLLED Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
OUTLET SITE IN OUTLET 10 Yr
INFLOWS TO: CONTROLLED
--------------------
HYG file HYG ID
-----------------------
OUTLET
TOTAL FLOW INTO: CONTROLLED
----------------------------
HYG file HYG ID
----------------------------
CONTROLLED
---------- Volume Peak Time Peak Flow
HYG tag ac-ft hrs cfs
--------------------------------------------
10 Yr 1.045 .1666 75.85
---------- Volume Peak Time Peak Flow
HYG tag ac-ft hrs cfs
--------------------------------------------
10 Yr 1.045 .1666 75.85
Type.... Node: Addition Summary Page 3.04
Name.... CONTROLLED Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 75.85 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.045 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 .00 75.82 75.85 .09 .00
AREA H APPENDIX I
Page 6 Of 16
Type.... Node: Addition Summary Page 3.05
Name.... CONTROLLED Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: CONTROLLED
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
OUTLET SITE IN OUTLET 25 Yr
INFLOWS TO: CONTROLLED
-----------------------
HYG file HYG ID
-----------------------
OUTLET
TOTAL FLOW INTO: CONTROLLED
----------------------------
HYG file HYG ID
----------------------------
CONTROLLED
---------- Volume Peak Time Peak Flow
HYG tag ac-ft hrs cfs
--------------------------------------------
25 Yr 1.164 .1666 84.54
---------- Volume Peak Time Peak Flow
HYG tag ac-ft hrs cfs
------------------------------------- ------
25 Yr 1.164 .1666 84.54
Type.... Node: Addition Summary Page 3.06
Name.... CONTROLLED Evert: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = CONTROLLED
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 84.54 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.164 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
---------i-------------------------------------------------------------
.0000 .00 84.51 84.54 .10 .00
AREA H APPENDIX I
Page 7 of 16
Type.... Node: Pond Inflow Summary Page 4.01
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
- ---------- ------------------------- -
Upstream Link ID Upstream Node ID. HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 PRIMARY SITE PRIMARY SITE 2 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
----------------------------------------------------- -------------------
PRIMARY SITE 2 Yr .805 .1666 58.47
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
SITE IN 2 Yr .805 .1666 58.47
Type.... Node: Pond Inflow Summary Page 4.02
Name.... SITE IN Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 2 Yr
-----------------------------------
Peak Discharge = 58.47 cfs
Time to Peak = .166.6 hrs
HYG Volume = .805 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I--------------------------------------------------------------
.0000 1 .00 58.45 58.47 .07 .00
AREA H APPENDIX I
Page 8 of 16
Type.... Node: Pond Inflow Summary Page 4.03
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
Upstream Link ID Upstream Node ID HYG file HYG ID HYG tag
--------------------------------------------------------------------------
ADDLINK 20 PRIMARY SITE PRIMARY SITE 10 Yr
INFLOWS TO: SITE IN
----------- ------------------ ----- ----- - Volume Peak Time Peak Flow
HYG file
----------- HYG ID
------------------ HYG
----- tag
----- ac-ft
-
- hrs cfs

PRIMARY SITE
10
Yr -
--------
1.045 -------------
.1666 ----------
75.85
TOTAL FLOW INTO: SITE IN
----------- ------------------ ----- ----- - Volume Peak Time Peak Flow
HYG file
----------- HYG ID
------------------ HYG
----- tag
----- ac-ft
----
-- hrs cfs

SITE IN
10
Yr -
----
1.045 -------------
.1666 ----------
75.85
Type.... Node: Pond Inflow Summary Page 4.04
Name.... SITE IN Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 75.85 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.045 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time 1 Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
--------- I-------------------------------------------------------
.0000 1 .00 75.82 75.85 .09 .00
AREA H APPENDIX I
Page 9 of 16
Type.... Node: Pond Inflow Summary Page 4.05
Name.... SITE IN Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY FOR HYDROGRAPH ADDITION
at Node: SITE IN
HYG Directory: C:\Gaston Mall Pondpack\Rational - 4th set of calc's\
-----------------------------
Upstream Link ID Upstream Node ID HYG file HYG ID HYG taa
--------------------------------------------------------------------------
ADDLINK 20 PRIMARY SITE PRIMARY SITE 25 Yr
INFLOWS TO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
-------------------------------------------------------------------------
PRIMARY SITE 25 Yr 1.164 .1666 84.54
TOTAL FLOW INTO: SITE IN
---------------------------------------- Volume Peak Time Peak Flow
HYG file HYG ID HYG tag ac-ft hrs cfs
--------------------------------------------------------------------------
SITE IN 25 Yr 1.164 .1666 84.54
Type.... Node: Pond Inflow Summary Page 4.06
Name.... SITE IN Event: 25 yr.
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PR.IMARY SITE RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TOTAL NODE INFLOW...
HYG file =
HYG ID = SITE IN
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 84.54 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.164 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs Time on left represents time for first value in each row.
------ I----------------
----------------------------------------------
.0000 1 .00 84.51 84.54 .10 .00
AREA H APPENDIX 1
Page 10 of 16
Type.... C and Area Page 5.01
Name.... PRIMARY SITE Tag: PRE
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
RATIONAL C COEFFICIENT DATA
------------------------------------------------------------------------
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Predeveloped Portion of the site .2500 5.028 1.257
Ex. Developed .8500 10.882 9.250
WEIGHTED C & TOTAL AREA ---> .6604 15.910 10.507
AREA H APPENDIX I
Page 11 of 16
Type.... Rational Predev. Peak Q Page 5.02
Name.... PRIMARY SITE Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAR DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag
----- Freq
----- File
- IDF Curve

2 Yr -
2 ----
- ------ ----------------
2 year Gastonia
T'c = .2265 hrs
--

Tag
Freq
C
C adj ---------------------------
I C I Area
Peak Q

----- (years)
------
----- factor
------ I final in/hr acres 1
--
- cfs

2 Yr
2
.660
1.000 -
------------------------- I
I
1 .660 3.9523 15.910 I
----------------------------- ----------
41.87
Type.... Mod. Rational Graph Page 5.03
Name.... PRIMARY SITE Tag: 2 Yr Event: 2 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 2 yr I Allowable Outflow: 41.87 cfs
* 'C' Adjustment: 1.000 1 Required Storage: .250 ac-ft
*---------------------------------------------------------------------*
* Peak Inflow: 58.47 cfs
* HYG File: 2 Yr
**********************************************************************
Q
Td = .1667 hrs I Return Freq: 2 yr
------ Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I
I
Tc= .0833 hrs
I = 5.6396 in/hr 1 Area = 15.910 acres
Q = 74.19 cfs I Weighted C = .820
I• I Adjusted C = .820
• I I
I Required Storage
-- .250 ac-ft I Td= .1667 hrs
I I = 4.4448 in/hr
x x x x x x x I x x x x x x x x x x x Q= 58.47 cfs
• I
x x
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 41.87 cfs
x o I. Ix (Allow.Outflow)
o 1
x o 1 NOT TO SCALE I x
0 1 _____= I
0 I I x
-----------------------I-----------------------------I------------
.1196 hrs .1903 hrs T
AREA H APPENDIX I
Page 12 of 16
Type.... C and Area Page 5.04
Name.... PRIMARY SITE Tag: POST
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
RATIONAL C COEFFICIENT DATA
-------------------------------------------------------------------------
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Primary Development .8200 15.910 13.046
WEIGHTED C & TOTAL AREA ---> .8200 15.910 13.046
AREA H APPENDIX I
Page 13 of 16
-
Type.... Rational Predev. Peak Q Page 5.05
Name.... PRIMARY SITE Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Tc = .2265 hrs
.-----------------------------.
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I --------
10 Yr 10 .660 1.000 I .660 5.1289 15.910 I 54.34
-----------------------------
Type.... Mod. Rational Graph Page 5.06
Name.... PRIMARY SITE Tag: 10 Yr Event: 10 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRI_MARY SITE RATIONAL.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
**********************************************************************
* RETURN FREQUENCY: 10 yr I Allowable Outflow: 54.34 cfs
* 'C' Adjustment: 1.000 I Required Storage: .323 ac-ft
*-------------------------------------
-------------------------------
* Peak Inflow: 75.85 cfs
* HYG File: 10 Yr
Q I Td = .1667 hrs I Return Freq: 10 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I I
i I
I Tc= .0833 hrs
I I = 7.1995 in/hr Area = 15.910 acres
Q = 94.71 cfs I Weighted C = .820
I I• I Adjusted C = .820
I i I
I Required Storage I
I -- .323 ac-ft Td= .1667 hrs
i i I I I= 5.7657 in/hr
I x x x x x x x l x x x x x x x x x x x Q= 75.85 cfs
I I
I x x
I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 54.34 cfs
I x o I. Ix (Allow.Outflow)
i o I 1
I x o NOT TO SCALE I x
I 0 I
l 0 1 x
------------------------ I----------=------------------I------------
.1189 hrs .1903 hrs T
AREA H APPENDIX I
Page 14 of 16
Type.... Rational Predev. Peak Q Page 5.07
Name.... PRIMARY SITE Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONA-L.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Tc = .2265 hrs
.-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I ----------------------------- I ----------
25 Yr 25 .660 1.000 1 .660 5.6885 15.910 I 60.27
-----------------------------
Type.... Mod. Rational Graph Page 5.08
Name.... PRIMARY SITE Tag: 25 Yr Event: 25 yr
File.... C:\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE RATIONAL.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD
---- Graphical Summary for Maximum Required Storage ----
Method T
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
* RETURN FREQUENCY: 25 yr I Allowable outflow: 60.27 cfs
* 'C' Adjustment: 1.000 1 Required Storage: .364 ac-ft
*--------------------------------------------------------------------*
* Peak Inflow: 84.54 cfs
* HYG File: 25 Yr
Q I Td = .1667 hrs I Return Freq: 25 yr
/------- Approx. Duration for Max. Storage ------/ C adj.factor:1.000
I I
I I
Tc= .0833 hrs I
I I = 8.0394 in/hr 1 Area = 15.910 acres
I Q = 105.76 cfs 1 Weighted C = .820
I- Adjusted C = .820
I I 1
I I Required Storage I
-- .364 ac-ft I Td= .1667 hrs
I I l I = 6.4265 in/hr
x x x x x x x l x x x x x x x x x x x Q= 84.54 cfs
I I
x x
0 0 0 0 0 0 0 0 0° 0° 0 0 0 0 Q= 60.27 cfs
x o 1. Ix (Allow.Outflow)
I 0 I 1
1 x 0 NOT TO SCALE I x
I ° I I x
------------------------ I-----------------------------
.1192 hrs .1906 hrs T
AREA H
APPENDIX I
Page 15 of 16
Appendix A
Index of Starting Page Numbers for ID Names
----- 1 -----
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- C -----
CONTROLLED 2 Yr... 3.01, 3.03, 3.05
----- P -----
PRIMARY SITE PRE... 5.01, 5.02,
5.03, 5.04, 5.05, 5.06, 5.07,
5.08
----- S SITE IN 2 Yr... 4.01, 4.03,
4.05
----- W -----
Watershed... 1.01, 1.02
A-1
AREA H APPENDIX I
Page 16 of 16
ROUTING CALCULATIONS
FOR AREA H
Table of Contents
x,r+*:rx*f***txxxx***:t MASTER SUMMARY ***x*xt:tx*x,r*,r:**+x
Watershed....... Mod. Rational Grand Summary ........ 1.01
Master Network Summary ............. 1.02
:* ***rx t.x xt*+t RAINFALL DATA *******=xt**z rx *rtx*
10 Year Gastonia 10 Yr I-D-F Table .................. 2.01
2 year Gastonia 2 Yr I-D-F Table ................... 2.02
25 Year Gastonia 25 Yr I-D-F Table .................. 2.03
50 Year Gastonia 50 Yr I-D-F Table .................. 2.04
xx*****x:r*****x,r** TIME VS.VOL ******xx:r-r*+***tx:?i:t
SITE.......... 2 Yr Time vs. Volume 3.01
SITE......... 10 Yr Time vs. Volume ................. 3.03
SITE......... 25 Yr Time vs. Volume ................. 3.05
SITE......... 50 Yr Time vs. Volume ................. 3.07
* ****************** OUTLET STRUCTURES *********************
Out to Creek.... Outlet Input Data .................. 4.01
Composite Rating Curve ............. 4.05
****************** RATIONAL METHOD CALCS *******************
PRIMARY SITE.... Rational Predev. Peak Q ............ 5.01
PRIMARY SITE.... PRE C and Area ..................... 5.02
PRIMARY SITE.... 2 Yr
Mod. Rational Storm Calcs .......... 5.03
Mod. Rational Hyg .................. 5.04
PRIMARY SITE.... POST C and Area ..................... 5.05
PRIMARY SITE.... 10 Yr
Mod. Rational Storm Calcs .......... 5.06
Mod. Rational Hyg .................. 5.07
PRIMARY SITE.... 25 Yr
Mod. Rational Storm Calcs .......... 5.06
Mod. Rational Hyg .................. 5.09
AREA H ROUTING CALCULATIONS
Page 1 of 35
APPENDIX J
Type.... Mod. Rational Grand Summary Page 1.01
Name.... Watershed
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
************************************************************************
* *
*
* MODIFIED RATIONAL METHOD
* ---- Grand Summary For All Storm Frequencies ----
* *
* *
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)

................ Area =
......... 20.460 acres
.................. Tc
............... = .0833
....... hrs
...........
................ ......... ......... ......... ............... ..................
VOLUMES
Freq. Adjusted Duration I Qpeak Allowable) Inflow Storage
years 'C' hrs in/hr cfs cfs ac-ft ac-ft
--------------- --------- ----------------------------- I ---------------------
2 .861 .2000 4.1696 74.07 46.40 I .. 1.224 .483
10 .861 .2000 5.4101 96.11 60.22 1.589 .626
25 .861 .2000 6.0145 106.85 66.79 1.766 .698
50 .861 .2000 6.4627 114.81 71.75 1.898 .751

AREA H ROUTING CALCULATIONS APPENDIX J
Page 2 of 35
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
MASTER DESIGN STORM SUMMARY
Default Network Design Storm File, ID Gastonia
Rainfall
Retu
---- rn Event
-------- Type
--- IDF ID

2
Yr -----------
I-D-F Curve - -------
2 year ---------
Gastonia
10 Yr I-D-F Curve 10 Year Gastonia
25 Yr I-D-F Curve 25 Year Gastonia
50 Yr I-D-F Curve 50 Year Gastonia
---------------------------
ICPM CALCULATION TOLERANCES
Target Convergence= .000 cfs +/-
Max. Iterations = 50 loops
ICPM Time Step = .0250 hrs
Output Time Step = .0833 hrs
ICPM Ending Time = 35.0000 hrs
-------------------------------
MASTER NETWORK SUMMARY
Modified Rational Method Network
(*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
-

CS
POND
2 ---------
.974
CS POND 10 1.492
CS POND 25 1.761
CS POND 50 1.659
CS OUT POND 2 1.126
CS OUT POND 10 1.505
CS OUT POND 25 1.646
CS OUT POND 50 1.750
Max
Qpeak Qpeak Max WSEL Pond Storage
hrs
------- cfs
-------- ft
------ ac-ft

14.27 -- ------------
.2499 26.08
.2499 37.68
.2499 37.58
.2499 12.27 705.19 .000
.3332 21.52 705.59 .000
.2499 32.95 706.01 .000
.2499 36.36 706.12 .000
AREA H ROUTING CALCULATIONS APPENDIX J
Page 3 of 35
Type.... Master Network Summary Page 1.03
Name.... Watershed
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4 th set of cal c's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
------
-----------
ICPM CALCULATION
---------------- -----------
TOLERANCES ---
------------
Target Convergence= .000 ---
cfs +/-
Max. Iterations = 50 loops
ICPM Time Step = .0250 hrs
Output Time Step = .0833 hrs
ICPM Ending Time
----------------- = 35.0000
------------ hrs
--
MASTER NETWORK SUMMARY
Modified Rational Method Network
( *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

*DUHARTS CREEK JCT
2 -- --
1.125 -------
.2499 --------
12.27 -------- ------------
*DUHARTS CREEK JCT 10 1.504 .3332 21.52
*DUHARTS CREEK JCT 25 1.646 .2499 32.95
*DUHARTS CREEK JCT 50 1.749 .2499 36.36
PRIMARY SITE AREA 2 1.224 .1666 74.07
PRIMARY SITE AREA 10 1.589 .1666 96.11
PRIMARY SITE AREA 25 1,766 .1666 106.85
PRIMARY SITE AREA 50 1.898 .1666 114.81
SITE POND 2 1.184 .1666 71.10
SITE POND 10 1.536 .1666 92.25
SITE POND 25 1.707 .1666 102.56
SITE POND 50 1.834 .1666 110.20
SITE OUT POND 2 974 .2499 14.27 705.37 1.011
SITE OUT POND 10 1.492 .2499 26.08 706.68 1.204
SITE OUT POND 25 1.761 .2499 37.68 708.42 1.267
SITE OUT. POND 50 1.659 .2499 37.58 708.68 1.339
AREA H ROUTING CALCULATIONS APPENDIX J
Page 4 or 35
Type.... I-D-F Table Page 2.01
Name.... 10 Year Gastonia Tag: 10 Yr Event: 10 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- ---------
--
.0833 7.2000
.1670 5.7600
.2500 4.8800
.5000 3.6200
1.0000 2.3000
Type.... I-D-F Table Page 2.02
Name.... 2 year Gastonia Tag: 2 Yr Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc`s\
Storm... 2 year Gastonia Tag: 2 Yr
Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- --------
---
.0833 5.6400
.1670 4.4400
.2500 3.7600
5000 2.5800
1.0000 .9500
Type.... I-D-F Table Page 2.03
Name.... 25 Year Gastonia Tag: 25 Yr Event: 25 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
Rainfall-Intensity-Duration Curve
Time,,hrs Intens., in/hr
----------- -----------
.0833 8.0400
.1670 6.4200
.2500 5.4000
.5000 4.0200
1.0000 2.6700
Type.... I-D-F Table Page 2.04
Name.... 50 Year Gastonia Tag: 50 Yr Event: 50 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 50 Year Gastonia Tag: 50 Yr
" Rainfall-Intensity-Duration Curve
Time, hrs Intens., in/hr
----------- -----------
.0833 8.6400
.1670 6.9000
.2500 5.8000
.5000 4.3800
1.0000 2.9600
AREA N ROUTING CALCULATIONS APPENDIX J
Page 5 of 35
Type.... Time vs. Volume Page 3.01
Name.... SITE Tag: 2 Yr Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondp ack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TIME vs. VOLUME (ac-ft)
Time I Output Time increment = .0833 hrs
hrs I Time on left
---------------- represents
----------- time for first
-- value in each row.

.0000 I
.000
.242 ------------ -
.698 --------
.980 ------------
1.011
.4165 .957 .912 .876 .848 .824
.8330 I .807 .792 .777 .722 .672
1.2495 I .626 .578 .554 .545 ,510
1.6660 .477 ,447 .416 .393 .372
2.0825 .351 .331 .313 .290 .269
2.4990 I .250 .238 .227 .217 .200
2.9155 .187 .178 ,171 .161 .150
3.3320 I .139 .130 .122 .115 .109
3.7485 .103 .096 .090 .084 .079
4.1650 .074 .070 .066 .062 .058
4.5815 I .055 .051 .049 .046 .043
4.9980 I .041 .039 .037 .035 .033
5.4145 .032 .030 .029 .028 .027
5.8310 I .026 .025 .024 .023 .022
6.2475 .021 .020 .020 .019 .019
6.6640 I .018 .017 .017 .016 .016
7.0805 I .016 .015 .015 .014 .014
7.4970 I .014 .013 .013 .013 .012
7.9135 I .012 .012 .011 .011 .011
8.3300 .011 .010 .010 .010 .010
8.7465 I .010 .009 ,009 .009 ,009
9.1630 .009 .009 .008 .008 .008
9.5795 I .008 .008 .008 .008 .007
9.9960 I ,007 .007 .007 .007 .007
10.4125 .007 .007 .007 .006 .006
10.8290 .006 .006 .006 .006 .006 r
11.2455 I .006 .006 .006 .006 .005
11.6620 ( .005 .005 .005 .005 .005
12.0785 I .005 .005 .005 .005 .005
12.4950 I .005 .005 .005 .005 .005
12.9115 I .004 .004 ,004 .004 .004 r
13.3280 I .004 .004 .004 .004 .004
13.7445 I .004 .004 .004 .004 .004
14.1610 I .004 .004 ,004 .004 .004
14.5775 I ,004 .004 .004 .004 .004
14.9940 I .004 .003 .003 .003 .003
15.4105 I .003 .003 .003 .003 .003
15.8270 I .003 .003 .003 .003 .003
16.2435 .003 .003 .003 .003 .003
16.6600 I .003 ,003 .003 .003 .003
17.0765 I .003 .003 .003 .003 .003
17.4930 .003 .003 .003 .003 .003
AREA H ROUTING CALCULATIONS APPENDIX J -
Page 6 of 35
Type.... Time vs. Volume Page 3.02
Name.... SITE Tag: 2 Yr Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondp ack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
TIME vs. VOLUME (ac-ft)
Time Output Time increment = .0833 hrs
hrs I
---------I---- Time on left
------------ represents
----- time for first value in each row.

17.9095 I

.003 ------

.003 ---------------

.003 -
-------
.003
------------
.003
18.3260 I .002 .002 .002 .002 .002
18.7425 .002 .002 .002 .002 .002
19.1590 .002 .002 .002 .002 .002
19.5755 I .002 .002 .002 .002 .002
19.9920 .002 .002 .002 :002 .002
20.4085 I .002 .002 .002 .002 .002
20.8250 I .002 .002 .002 .002 .002
21.2415 I .002 .002 .002 .002 .002
21.6580 I .002 .002 .002 .002 .002
22.0745 I .002 .002 .002 .002 .002
22.4910 .002 .002 .002 .002 .002
22.9075 I .002 .002 .002 .002 .002
23.3240 I .002 .002 .002 .002 .002
23.7405 ) .002 .002 .002 .002 .002
24:1570 .002 .002 .002 .002 .002
24.5735 I .002 .002 .002 .002 .002
24.9900 I .002 .002 .002 .002 .001
25.4065 I .001 .001 .001 .001 .001
25.8230 I .001 .001 .001 .001 .001
26.2395 I .001 .001 .001 .001 .001
26.6560 I .001 .001 .001 .001 .001
27.0725 I .001 .001 .001 .001 .001
27.4890 I .001 .001 .001 .001 .001
27.9055 I .001 .001 .001 .001 .001
28.3220 I .001 .001 .001 .001 .001
28.7385 I .001 .001 .001 .001 .001
29.1550 .001 .001 .001 .001 .001
29.5715 .001 .001 .001 .001 .001
29.9880 I .001 .001 .001 .001 .001
30.4045 I .001 .001 .001 .001 .001
30.8210 I .001 .001 .001 .001 .001
31.2375 .001 .001 .001 .001 .001
31.6540 I .001 .001 .001 .001 .001
32.0705 I .001 .001 .001 .001 .001
32.4870 i .001 .001 .001 .001 .001
32.9035 .001 .001 .001 .001 .001
33.3200 I .001 .001 .001 .001 .-001
33.7365 I .001 .001 .001 .001 .001
34.1530 I .001 .001 .001 .001 .001
34.5695 .001 .001 .001 .001 .001
34.9860 I .001
AREA H ROUTING CALCULATIONS
Page 7 of 35
APPENDIX J
Type.... Time vs. Volume Page 3.03
Name.... SITE Tag: 10 Yr Event: 10 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th se t of calc's\PRIMARY SITE WITH HT AND
MS FOR ROUTI NG.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TIME vs. VOLUME (ac-ft)
Time Output Time increment = .0833 hrs
hrs
-------- Time on left
-I----------------- represents time for first
------- value in each row.

.0000
.000 ------
.312 ------------
.889 ------
1.204 --------------
1.186
.4165 1.090 1.015 .957 .913 .877
.8330 .848 .825 .807 .792 .734
1.2495 .682 .629 .602 .593 .553
1.6660 .517 .484 .450 .433 .397
2.0825 .374 .354 .336 .317 .300
2.4990 .284 .265 .246 .229 .219
2.9155 .205 .194 .186 .175 .163
3.3320 .151 .142 .134 .126 .117
3.7485 .110 .103 .098 .093 .086
4.1650 .081 .076 .072 .067 .063
4.5815 .059 .056 .053 .050 .047
4.9980 .044 .042 .040 .038 .036
5.4145 .? - .034 .032 .031 .030 .028
5.8310 .027 .026 .025 .024 .023
6.2475 .022 .021 .021 .020 .019
6.6640 .019 .018 .018 .017 .017
7.0805 .016 .016 .015 .015 .014
7.4970 .014 .014 .013 .013 .013
7.9135 .012 .012 .012 .012 .011
8.3300 .011 .011 .011 .010 .010
8.7465 .010 .010 .010 .009 .009
9.1630 .009 .009 .009 .008 .008
9.5795 .008 .008 .008 .008 .008
9.9960 .007 .007 .007 .007 .007
10.4125 .007 .007 .007 .007 .006
10.8290 .006 .006 .006 .006 .006
11.2455 .006 .006 .006 .006 .006
11.6620 .006 .005 .005 .005 .005
12.0785 .005 .005 .005 .005 .005
12.4950 .005 .005 .005 .005 .005
12.9115 .005 .005 .004 .004 .004
13.3280 .004 .004 .004 .004 .004
13.7445 .004 .004 .004 .004 .004
14.1610 .004 .004 .004 .004 .004
14.5775 .004 .004 .004 .004 .004
14.9940 .004 .004 .003 .003 .003
15.4105 .003 .003 .003 .003 .003
15.8270 ) .003 .003 .003 .003 .003
16.2435 .003 .003 .003 .003 .003
16.6600 .003 .003 .003 .003 .003
17.0765 .003 .003 .003 .003 .003
17.4930 .003 .003 .003 .003 .003
AREA H ROUTING CALCULATIONS APPENDIX J
Page 8 of 35
Type.... Time vs. Volume Page 3.04
Name.... SITE Tag: 10 Yr Event: 10 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTI NG.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
TIME vs. VOLUME (ac-ft)
Time I Output Time increment = .0833 h rs
hrs
-------- I Time on left
-I----------------- represents time for first
-------
- value in each row.

17.9095
I .003 ------
.003 --
---------
.003 -------
.003 ------------
.003
18.3260 I .003 .002 .002 .002 .002
18.7425 .002 .002 .002 .002 .002
19.1590 I .002 .002 .002 .002 .002
19.5755 I .002 .002 .002 .002 .002
19.9920 I .002 .002 .002 .002 .002
20.4085 I .002 .002 .002 .002 .002
20.8250 I .002 .002 .002 .002 .002
21.2415 I .002 .002 .002 .002 .002
21.6580 I .002 .002 .002 .002 .002
22.0745 I .002 .002 .002 .002 .002
22.4910 I .002 .002 .002 .002 .002
22.9075 .002 .002 .002 .002 .002
23.3240 I .002 .002 .002 .002 .002
23.7405 I .002 .002 .002 .002 .002
24.1570 I .002 .002 .002 .002 .002
24.5735 I .002 .002 .002 .002 .002
24.9900 I .002 .002 .002 .002 .002
25.4065 I .002 .001 .001 .001 .001
25.8230 .001 .001 .001 .001 .001
26.2395 I 001 .001 .001 .001 .001
26.6560 .001 .001 .001 .001 .001
27.0725 I .001 .001 .001 .001 .001
27.4890 I .001 .001 .001 .001 .001
27.9055 I .001 .001 .001 .001 .001
28.3220 I ,001 .001 .001 .001 .001
28.7385 I .001 .001 .001 .001 .001
29.1550 I .001 .001 .001 .001 .001
29.5715 I .001 .001 .001 .001 .001
29.9880 I .001 .001 .001 .001 .001.
30.4045 I .001 .001 .001 .001 .001
30.821.0 I .001 .001 .001 .001 .001
31.2375 I .001 .001 .001 .001 .001
31.6540 I .001 .001 .001 .001 .001
32.0705 I .001 .001 .001 .001 .001
32.4870 I .001 .001 .001 .001 .001
32.9035 I .001 .001 .001 .001 .001
33.3200 I .001 .001 .001 .001 .001
33.7365 I .001 .001 .001 .001 .001
34.1530 I .001 .001 .001 .001 .001
34.5695 I .001 .001 .001 .001 ,001
34.9860 I .001
AREA H ROUTING CALCULATIONS APPENDIX J
Page 9 of 35
Type.... Time vs. Volume Page 3.05
Name.... SITE Tag: 25 Yr Event: 25 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set o f calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTI NG.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TIME vs. VOLUME (ac-ft)
Time Output Time increment = .0833 hrs
hrs
-------- I Time on left
-I----------------- represents time for first
----- value in each row.

.0000
.000 --------
.346 ------------
.977 ----------
1.267 ----------
1.213
.4165 I 1.120 1.038 .975 .927 .888
.8330 .858 .833 .811 .793 .733
1.2495 I .676 .667 .638 .595 .555
1.6660 i .516 .480 .474 .455 .427
2.0825 I .395 .363 .334 .316 .300
2.4990 I .285 .271 .257 .244 .228
2.9155 I .213 .205 .190 .176 .163
3.3320 I .154 .148 .140 .131 .122
3.74B5 .113 .106 .099 .093 .088
4.1650 I .083 .078 .073 .069 .065
4.5815 I .061 .057 .054 .051 .048
4.9980 .045 .043 .040 .038 .036
5.4145 I .035 .033 .032 .030 .029
5.8310 I .028 .026 .025 .024 .023
6.2475 .023 .022 .021 .020 .020
6.6640 I .019 .018 .018 .017 .017
7.0805 I .016 .016 .015 .015 .015
7.4970 I .014 .014 .014 .013 .013
7.9135 I .013 .012 .012 .012 .011
8.3300 .011 .011 .011 .010 .010
8.7465 I .010 .010 .010 .009 .009
9.1630 .009 .009 .009 .009 .008
9.5795 I .008 .008 .008 .008 .008
9.9960 .008 .007 .007 .007 .007
10.4125 I .007 .007 .007 .007 .007
10.8290 .006 .006 .006 .0066 .006
11.2455 I .006 .0066 .006 .006 .006
11.6620 I .006 .005 .005 .005 .005
12.0785 I .005 .005 .005 .005 .005
12.4950 I .005 .005 .005 .005 .005
12.9115 I .005 .005 .004 .004 .004
13.3280 I .004 .004 .004 .004 .004
13.7445 I .004 .004 .004 .004 .004 _,
14.1610 I .004 .004 .004 .004 .004
14.5775 I .004 .004 .004 .004 .004
14.9940 I .004 .004 .004 .003 .003
15.4105 I .003 .003 .003 .003 .003
15.8270 I .003 .003 .003 .003 .003
16.2435 I .003 .003 .003 .003 .003
16.6600 I .003 .003 .003 .003 .003
17.0765 .003 .003 .003 .003 .003
17.4930 I .003 .003 .003 .003 .003
AREA H ROUTING CALCULATIONS APPENDIX J
Page 10 of 35
Type.... Time vs. volume Page 3.06
Name.... SITE Tag: 25 Yr Event: 25 yr
rile.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of Calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTI NG.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
TIME vs. VOLUME (ac-ft)
Time Output Time increment = .0833 h rs
hrs
-------- Time on left
-I----------------- represents time for first
---------- value in each row.

17.9095
.003 --
.003 -------------
.003 -------
.003 ---
.003
18.3260 .003 .003 .002 .002 .002
18.7425 .002 .002 .002 .002 .002
19.1590 .002 .002 .002 .002 .002
19.5755 .002 .002 .002 .002 .002
19.9920 .002 .002 .002 .002 .002
20.4085 .002 .002 .002 .002 .002
20.8250 .002 .002 .002 .002 .002
21.2415 .002 .002 .002 .002 .002
21.6580 .002 .002 .002 .002 .002
22.0745 .002 .002 .002 .002 .002
22.4910 .002 .002 .002 .002 .002
22.9075 .002 .002 .002 .002 .002
23.3240 .002 .002 .002 .002 .002
23.7405 .002 .002 .002 .002 .002
24.1570 .002 .002 .002 .002 .002
24.5735 .002 .002 .002 .002 .002
24.9900 .002 .002 .002 .002 .002
25.4065 I .002 .001 .001 .001 .001
25.8230 .001 .001 .001 .001 .001
26.2395 .001 .001 .001 .001 .001
26.6560 .001 .001 .001 .001 .001
27.0725 .001 .001 .001 .001 .001
27.4890 .001 .001 .001 .001 .001
27.9055 .001 .001 .001 .001 .001
28.3220 .001 .001 .001 .001 .001
28.7385 .001 .001 .001 .001 .001
29.1550 .001 .001 .001 .001 .001
29.5715 .001 .001 .001 .001 .001
29.9880 .001 .001 .001 .001 .001
30.4045 .001 .001 .001 .001 .001
30.8210 .001 .001 .001 .001 .001
31.2375 .001 .001 .001 .001 .001
31.6540 .001 .001 .001 .001 .001
32.0705 .001 .001 .001 .001 .001
32.4870 .001 .001 .001 .001 .001
32.9035 .001 .001 .001 .001 .001
33.3200 .001 .001 .001 .001 .001
33.7365 .001 .001 .001 .001 .001
34.1530 .001 .001 .001 .001 .001
34.5695 .001 .001 .001 .001 .001
34.9860 .001
AREA H ROUTING CALCULATIONS APPENDIX J
Page 11 of 35

Type....
Time vs. Volume tr• i
Page 3.07
Name.... SITE Tag: 50 Yr Eve nt: 50 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTI NG.PPW
Storm... 50 Year Gastonia Tag: 50 Yr
TIME vs. VOLUME (ac-ft)
Time I Output Time increment = .0833 hrs
hrs
-------- ( Time on left
-I----------------- represents time for first
----------- value in each row.

.0000

I .000 --

.371 -------
-----
1.044
----------
1.339
----------
1.257
.4165 I 1.152 1.062 .993 .941 .899
.8330 I .866 .840 .820 .801 .747
1.2495 I .735 .684 .637 .593 .549
1.6660 I .526 .518 .485 .454 .426
2.0825 I .402 .378 .356 .330 .305
2.4990 I .282 .268 .255 ,243 .232
2.9155 I .221 .204 .189 .176 .167
3.3320 .161 .152 .141 .131 .124
3.7485 .117 .109 .102 .095 .089
4.1650 I .084 .079 .075 .070 .066
4.5815 I .062 .058 .055 .052 .049
4.9980 I .046 .043 .041 .039 .037
5.4145 I .035 .034 .032 .030 .029
5.8310 .028 .027 .026 .025 .024
6.2475 I .023 .022 .021 .020 .020
6.6640 I .019 .019 .018 .017 .017
7.0805 I .016 .016 .016 .015 .015
7.4970 I .014 .014 .014 .013 .013 T
7.9135 .013 .012 .012 .012 .011
8.3300 I .011 .011 .011 .010 .010
8.7465 I .010 .010 .010 .009 .009
9.1630 .009 .009 .009 .009 .008
9.5795 I .008 .008 .008 .008 .008
9.9960 I .008 .007 .007 .007 .007
10.4125 .007 .007 .007 .007 .007
10.8290 .006 .006 .006 .006 .006
11.2455 I .006 .006 .006 .006 .006
11.6620 I .006 .005 .005 .005 .005
12.0785 i .005 .005 .005 .005 ,005
12.4950 .005 .005 .005 .005 .005
12.9115 I .005 .005 .004 .004 .004
13.3280 i .004 .004 .004 .004 .004
13.7445 .004 .004 .004 .004 .004
14.1610 I .004 .004 .004 .004 ,004
14.5775 .004 .004 .004 .004 .004
14.9940 .004 .004 .004 .003 .003
15.4105 I .003 .003 .003 .003 .003
2.5.8270 .003 .003 .003 .003 .003
16.2435 I .003 .003 .003 .003 .003
16.6600 I .003 .003 .003 .003 .003
17.0765 I ,003 .003 .003 .003 .003
17.4930 I .003 .003 .003 .003 .003
AREA H ROUTING CALCULATIONS APPENDIX J
Page 12 of 35
Type.... Time vs. Volume Page 3.08
Name.... SITE Tag: 50 Yr Event: 50 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th se t of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 50 Year Gastonia Tag: 50 Yr
TIME vs. VOLUME (ac-ft)
Time Output Time increment = .0833 hrs
hrs
-------- I Time on left
-I----------------- represents time for first
------ value in each row.

17.9095

I .003 -------

.003 ---
---------
.003
------
.003
--------------
.003
18.3260 I .003 .003 .002 .002 .002
18.7425 I .002 .002 .002 .002 .002
19.1590 .002 .002 .002 .002 .002
19.5755 I .002 .002 .002 .002 .002
19.9920 .002 .002 .002 .002 .002
20.4085 I .002 .002 .002 .002 .002
20.8250 .002 .002 .002 .002 .002
21.2415 I .002 .002 .002 .002 .002
21.6580 I .002 .002 .002 .002 .002
22.0745 I .002 .002 .002 .002 .002
22.4910 I .002 .002 .002 .002 .002
22.9075 I .002 .002 .002 .002 .002
23.3240 I .002 .002 .002 .002 .002
23.7405 .002 .002 .002 .002 .002
24.1570 I .002 .002 .002 .002 .002
24.5735 .002 .002 .002 ,002 .002
24.9900 I .002 .002 .002 .002 .002
25.4065 I .002 .001 .001 .001 .001
25.8230 .001 .001 .001 .001 .001
26.2395 I .001 .001 .001 .001 .001
26.6560 I .001 .001 .001 .001 ,001
27.0725 I .001 .001 .001 .001 .001
27.4890 I .001 .001 .001 .001 .001
27.9055 I .001 .001 .001 .001 .001
28.3220 I .001 .001 ,001 .001 .001
28.7385 I 001 .001 .001 .001 .001
29.1550 I .001 .001 .001 .001 .001
29.5715 I .001 .001 .001 .001 .001
29.9880 I .001 .001 .001 .001 .001
30.4045 I .001 .001 .001 .001 ,001
30.8210 I .001 .001 .001 .001 .001
31.2375 I .001 .001 .001 .001 .001
31.6540 I .001 .001 .001 .001 001
32.0705 1 .001 .001 .001 .001 .001
32.4870 I .001 .001 .001 .001 .001
32.9035 I .001 .001 .001 .001 .001
33.3200 I .001 .001 .001 .001 .001
33.7365 I .001 .001 .001 .001 .001
34.1530 I .001 .001 .001 ,001 .001
34.5695 I .001 .001 .001 .001 .001
34.9860 I .001
AREA H ROUTING CALCULATIONS APPENDIX J
Page 13 of 35
Type.... Outlet Input Data Page 4.01
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 700.00 ft
Increment = .03 ft
Max. Elev.= 71.0.00 ft
**********************************************
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
G--- Reverse Flow ')nly (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall. E1, ft E2, ft
----------------- ---- ------- --------- ---------
User Defined Table U0 ---> TW .000 710.000
Weir-Rectangular WO ---> CO 704.420 710.000
Culvert-Circular CO ---> TW 700.000 710.000
TW SETUP, DS Channel
AREA H ROUTING CALCULATIONS APPENDIX J
Page 14 of 35
Type.... Outlet Input Data Page 4.02
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4t1i set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
OUTLET STRUCTURE INPUT DATA
Structure ID = U0
Structure Type = User Defined Table
------------------------------------
ELEV-FLOW RATING TABLE
Elev, ft Flow, cfs
--------- ---------
700.00 .00
701.50 .00
702.00 .75
702.50 1.60
704.00 1.70
709.50 1.70
710.00 1.70
Structure ID
Structure Type
--------------
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
Wo
Weir-Rectangular
----------------
1
704.42 ft
5.00 ft
3.130000
Weir TW effects (Use adjustment equation)
AREA H ROUTING CALCULATIONS APPENDIX J
Page 15 of 35
Type.... Outlet Input Data Page 4.03
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
OUTLET STRUCTURE INPUT DATA
Structure ID = Co
Structure Type = Culvert-Circular
------------------------------------
No. Barrels = 1
Barrel Diameter = 2.5000 ft
Upstream Invert = 700.00 ft
Dnstream Invert = 698.50 ft
Horiz. Length = 140.00 ft
Barrel Length = 140.01 ft
Barrel Slope = .01071 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0210
Ke = .5000 (forward entrance loss)
Kb = .024052 (per ft of full flow)
Kr .5000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0078
Inlet Control M = 2.0000
inlet Control c = .03790
Inlet Control Y = .690C
Tl ratio (HW/D) = 1,130
T2 ratio (HW/D) = 1.291
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below Tl ele:
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 = 702.83 ft ---> Flow = 27.16 cfs
At T2 Elev = 703.23 ft ---> Flow = 31.05 cfs
AREA H ROUTING CALCULATIONS APPENDIX J
Page 16 of 35
Type.... Outlet Input Data Page 4.04
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack_\Rational - 4th'set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
OUTLET STRUCTURE INPUT DATA
Structure ID = TW
Structure Type = TW SETUP, DS Channel
-------------------------------------
FREE OUTF_ALL 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
AREA H ROUTING CALCULATIONS APPENDIX J
Page 17 of 35
Type.... Composite Rating Curve Page 4.05
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of talc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge
-------------------------
Elev. Q TW Elev Error
ft
-------- cfs
------- f
----- t +/-ft
--- --- Contrib uti ng Structures

701.65
.23
Free --
Outfall ----
UO ----
(no ---
Q: -------------
WO,CO)
701.68 .26 Free Outfall UO (no Q: WO,CO)
701.70 .30 Free Outfall UO (no Q: WO,CO)
701.73 .34 Free Outfall UO (no Q: WO,CO)
701.75 .38 Free .Outfall UO (no Q: WO,CO)
701.78 .41 Free Outfall UO (no Q: WO,CO)
701.80 .45 Free Outfall UO (no Q: WO,CO)
701.83 .49 Free Outfall UO (no Q: WO,CO)
701.85 .52 Free Outfall UO (no Q: WO,CO)
701.88 .56 Free Outfall UO (no Q: WO,CO)
701.90 .60 Free Outfall UO (no Q: WO,CO)
701.93 .64 Free Outfall UO (no Q: WO,CO)
701.95 .68 Free Outfall UO (no Q: WO,CO)
701.98 .71 Free Outfall UO (no Q: WO,CO)
702.00 .75 Free Outfall UO (no Q: WO,CO)
702.03 .79 Free Outfall UO (no Q: WO,CO)
702.05 .83 Free Outfall UO (no Q: WO,CO)
702.08 .88 Free Outfall UO (no Q: WO,CO)
702.10 .92 Free Outfall UO (no Q: WO,CO)
702.13 .96 Free Outfall UO (no Q: WO,CO)
702.15 1.01 Free Outfall UO (no Q: WO,CO)
702.18 1.05 Free Outfall UO (no Q: WO,CO)
702.20 1.09 Free Outfall UO (no Q: WO,CO)
702.23 1.13 Free Outfall UO (no Q: WO,CO)
702.25 1.16 Free Outfall UO (no Q: WO,CO)
702.28 1.22 Free Outfall UO (no Q: WO,CO)
702.30 1.26 Free Outfall UO (no Q: WO,CO)
702.33 1.30 Free Outfall UO (no Q: WO,CO)
702.35 1.34 Free Outfall UO (no Q: WO,CO)
702.38 1.39 Free Outfall UO (no Q: WO,CO)
702.40 1.43 Free Outfall UO (no Q: WO,CO)
702.43 1.47 Free Outfall UO (no Q: WO,CO)
702.45 1.52 Free Outfall UO (no Q: WO,CO)
AREA H ROUTING CALCULATIONS APPENDIX J
Page 18 of 35
Type.... Composite Rating Curve
Name.... Out to Creek
Page 4.06
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th'set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q No tes
-------- -------- ----- --- Converge --- ---
-
---
---------------
E1ev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- --- Contributi ng Structures

702.48
1.56
Free --
Outfall ----
UO ----
(no ---
Q: ---------------
WO,CO)
702.50 1.60 Free Outfall UO (no Q: WO,CO)
702.53 1.60 Free Outfall UO (no Q: WO,CO)
702.55 1.60 Free Outfall UO (no Q: WO,CO)
702.58 1.61 Free Outfall UO (no Q: WO,CO)
702.60 1.61 Free Outfall UO (no Q: WO,CO)
702.63 1.61 Free Outfall UO (no Q: WO,CO)
702.65 1.61 Free Outfall UO (no Q: WO,CO)
702.68 1.61 Free Outfall UO (no Q: WO,CO)
702.70 1.61 Free Outfall UO (no Q: WO,CO)
702.73 1.61 Free Outfall UO (no Q: WO,CO)
702.75 1.62 Free Outfall UO (no Q: WO,CO)
702.78 1.62 Free Outfall UO (no Q: WO,CO)
702.80 1.62 Free Outfall UO (no Q: WO,CO)
702.83 1.62 Free Outfall UO (no Q: WO,CO)
'102.85 1.62 Free Outfall UO (no Q: WO,CO)
702.88 1.63 Free Outfall UO (no Q: WO,CO)
702.90 1.63 Free Outfall UO (no Q: WO,CO)
702.93 1.63 Free Outfall UO (no Q: WO,CO)
702.95 1.63 Free Outfall UO (no Q: WO,CO)
702.98 1.63 Free Outfall UO (no Q: WO,CO)
703.00 1.63 Free Outfall UO (no Q: WO,CO)
703.03 1.64 Free Outfall UO (no Q: W0,C0)
703.05 1.64 Free Outfall UO (no Q: WO,CO)
703.08 1.64 Free Outfall UO (no Q: WO,CO)
703.10 1.64 Free Ou.tfall UO (no Q: WO,CO)
703.13 1.64 Free Outfall UO (no Q: WO,CO)
703.15 1.64 Free Outfall UO (no Q: WO,CO)
703.18 1.64 Free Outfall UO (no Q: WO,CO)
703.20 1.65 Free Outfall UO (no Q: WO,CO)
703.23 1.65 Free Outfall UO (no Q: WO,CO)
703.25 1.65 Free Outfall UO (no Q: WO,CO)
703.28 1.65 Free Outfall UO (no Q: WO,CO)
AREA H ROUTING CALCULATIONS APPENDIX J
Page 19 of 35
Type.... Composite Rating Curve Page 4.07
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge ----------
---------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------- -------- ----- --------------------------
703.30 1.65 Free Outfall UO (no Q: WO,CO)
703.33 1.66 Free Outfall UO (no Q: WO,CO)
703.35 1.66 Free outfall UO (no Q: WO,CO)
703.38 1.66 Free Outfall UO (no Q: WO,CO)
703.40 1.66 Free Outfall UO (no Q: WO,CO)
703.43 1.66 Free Outfall UO (no Q: WO,CO)
703.45 1.66 Free Outfall UO (no Q: WO,CO)
703.48 1.66 Free Outfall UO (no Q: WO,CO)
703.50 1.67 Free Outfall UO (no Q: WO,CO)
703.53 1.67 Free Outfall UO (no Q: WO,CO)
703.55 1.67 Free Outfall UO (no Q: WO,CO)
703.58 1.67 Free Outfall UO (no Q:,WO,CO)
703.60 1.67 Free Outfall UO (no Q: WO,CO)
703.63 1.68 Free Outfall UO (no Q: WO,CO)
703.65 1.68 Free Outfall UO (no Q. WO,CO)
703.68 1.68 Free Outfall UO (no Q: WO,CO)
703.70 1.68 Free Outfall UO (no Q: WO,CO)
703.73 1.68 Free Outfall UO (no Q: WO,CO)
703.75 1.68 Free Outfall UO (no Q: WO,CO)
703.78 1.69 Free Outfall UO (no Q: WO,CO)
703.80 1.69 Free Outfall UO (no Q: WO,CO)
703.83 1.69 Free Outfall UO (no Q: WO,CO)
703.85 1.69 Free Outfall UO (no Q: WO,CO)
703.88 1.69 Free Outfall UO (no Q: WO,CO)
703.90 1.69 Free Outfall UO (no Q: WO,CO)
703.93 1.69 Free Outfall UO (no Q: WO,CO)
703.95 1.70 Free Outfall UO (no Q: WO,CO)
703.98 1.70 Free Outfall UO (no Q: WO,CO)
704.00 1.70 Free Outfall UO (no Q: WO,CO)
704.03 1.70 Free Outfall UO (no Q: WO,CO)
704.05 1.70 Free Outfall UO (no Q: WO,CO)
704.08 1.70 Free Outfall UO (no Q: WO,CO)
704.10 1.70 Free Outfall UO (no Q: WO,CO)
AREA H ROUTING CALCULATIONS APPENDIX J " l
Page 20 of 35
Type.... Composite Rating Curve
Name.... Out to Creek
Page 4.08
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engine er: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- - Contributing Structures

704.13
1.70
Free ----
Outfall -----------
UO (no Q: ---------------
WO,CO)
704.15 1.70 Free Outfall UO (no Q: WO,CO)
704.18 1.70 Free Outfall UO (no Q: WO,CO)
704.20 1.70 Free Outfall UO (no Q: WO,CO)
_ 704.23 1.70 Free Outfall UO (no Q: WO,CO)
704.25 1.70 Free Outfall UO (no Q: WO,CO)
704.28 1.70 Free Outfall UO (no Q: WO,CO)
704.30 1.70 Free Outfall UO (no Q: WO,CO)
704.33 1.70 Free Outfall UO (no Q. WO,CO)
704.35 1.70 Free outfall UO (no Q: WO,CO)
704.38 1.70 Free Outfall UO (no Q: WO,CO)
704.40 1.70 Free Outfall UO (no 0: WO,CO)
704.42 1.70 Free Outfall UO (no Q: WO,CO)
704.43 1.71 Free Outfall U0,W0,C0
704.45 1.78 Free Outfall UO,WO,CO
704.48 1.90 Free Outfall UO,WO,CO
704.50 2.05 Free Outfall UO,WO,CO
704.53 2.23 Free Outfall UO,WO,CO
704.55 2.43 Free Outfall UO,WO,CO
704.58 2.66 Free Outfall UO,WO,CO
704.60 2.89 Free Outfall UO,WO,CO
704.63 3.15 Free Outfall UO,WO,CO
704.65 3.43 Free Outfall UO,WO,CO
704.68 3.71 Free Outfall UO,WO,CO
704.70 4.02 Free Outfall UO,WO,CO
704.73 4.34 Free Outfall UO,WO,CO
704.75 4.67 Free Outfall UO,WO,CO
704.78 5.01 Free Outfall UO,WO,CO
704.80 5.37 Free outfall UO,WO,CO
704.83 5.73 Free Outfall UO,WO,CO
704.85 6.11 Free Outfall UO,WO,CO
704.88 6.50 Free Outfall UO,WO,CO
704.90 6.91 Free Outfall UO,WO,CO
AREA H ROUTING CALCULATIONS APPENDIX J
Page 21 Df 35
Type.... Composite Rating Curve Page 4.09
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mail Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge ------- -------------------
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- Contributing Structures

704.93
7.32
Free -----
Outfall --------------------------
UO,Wo,C0
704.95 7.74 Free Outfall U0,WO,C0
704.98 8.17 Free Outfall UO,W0,Co
705.00 8.61 Free Outfall UO,WO,CO
705.03 9.07 Free Outfall UO,WO,Co
705.05 9.53 Free Outfall U0,Wo,C0
705.08 9.99 Free Outfall UO,W0,C0
705.10 10.48 Free Outfall U0,W0,C0
705.13 10.97 Free Outfall U0,W0,C0
705.15 11.43 Free Outfall UO,WO,CO
705.18 11.97 Free outfall U0,W0,C0
705.20 12.48 Free Outfall UO,WO,CO
705.23 13.00 Free Outfall U0,W0,C0
705.25 13.54 Free outfall UO,WO,CO
705.28 14.07 Free Outfall U0,W0,C0
705.30 14.61 Free Outfall U0,W0,C0
705.33 15.15 Free outfall U0,W0,C0
705.35 15.74 Free Outfall U0,W0,C0
705.38 16.31 Free Outfall U0,W0,C0
705.40 16.88 Free Outfall UO,W0,CO
705.43 17.46 Free Outfall U0,W0,C0
705.45 18.07 Free Outfall U0,W0,C0
705.48 18.65 Free Outfall U0,W0,C0
705.50 19.27 Free Dutfall U0,W0,C0
705.53 19.88 Free Outfall UO,Wo,CO
705.55 20.49 Free Outfall U0,W0,C0
705.58 21.14 Free outfall U0,W0,C0
705.60 21.77 Free Outfall U0,WO,Co
705.63 22.40 Free Outfall UO,W0,C0
705.65 23.05 Free Outfall U0,W0,C0
705.68 23.71 Free Outfall U0,WO,CO
705.70 24.37 Free Outfall U0,W0,CO
705.73 25.04 Free Outfall U0,W0,C0
AREA H ROUTING CALCULATIONS APPENDIX J
Page 22 of 35
Type.... Composite Rating Curve Page 4.10
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge
-------------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------- -------- ----- --------------------------
705.75 25.70 Free Outfall U0,W0,C0
705.78 26.38 Free Outfall UO,WO,Co
105.80 27.07 Free Outfall UO,W0,C0
705.83 27.76 Free Outfall U0,W0,C0
705.85 28.46 Free Outfall UO,W0,C0
705.88 29.18 Free Outfall U0,W0,C0
705.90 29.88 Free Outfall U0,W0,C0
705.93 30.59 Free Outfall UO,WO,CO
705.95 31.31 Free Outfall UO,WO,CO
705.98 32.04 Free Outfall U0,W0,CO
706.00 32.78 Free Outfall UO,WO,CO
706.03 33.52 Free Outfall Uo,WO,Co
706.05 34.27 Free Outfall UO,WO,CO
706.08 35.02 Free Outfall U0,W0,C0
706.10 35.78 Free Outfall U0,WO,CO
706.13 36.39 Free Outfall U0,WO,CO
706.15 36.83 Free Outfall UO,WO,Co
706.18 37.21 Free Outfall Uo,WO,Co
706.20 37.55 Free Outfall Uo,W0,C0
706.23 37.84 Free Outfall UO,W0,C0
706.25 38.15 Free Outfall UO,WO,CO
706.28 38.43 Free Outfall UO,WO,Co
706.30 38.68 Free Outfall Uo,WO,Co
706.33 38.92 Free Outfall UO,WO,CO
706.35 39.19 Free Outfall Uo,W0,C0
706.38 39.43 Free Outfall UO,W0,C0
706.40 39.66 Free Outfall UO,W0,C0
706.43 39.88 Free Outfall Uo,W0,C0
706.45 40.09 Free Outfall Uo,W0,C0
706.48 40.29 Free Outfall UO,W0,C0
706.50 40.49 Free Outfall UO,WO,Co
706.53 40.69 Free Outfall Uo,W0,C0
706.55 40.88 Free Outfall Uo,W0,C0
AREA H ROUTING CALCULATIONS APPENDIX J
Page 23 of 35
Type.... Composite Rating Curve Page 4.11
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS E1ev, Total Q Notes
-------- -------- ----- --- Converge -----------------------
Elev. Q TW Elev Error
ft
-------- cfs
------- ft +/-ft
-------
- Contributing Structures

706.58
41.07
Free - --
--
Outfall ------------------------
U0,w0,C0
706.60 41.24 Free Outfall U0,w0,C0
706.63 41.43 Free Outfall U0,w0,C0
706.65 41.60 Free Outfall UO,WO,CO
706.68 41.77 Free Outfall UO1WO,CO
706.70 41.93 Free Out-fall U0,w0,C0
706.73 42.11 Free Outfall UO,WO,CO
706.75 42.26 Free Outfall UO,WO,CO
706.78 42.42 Free Outfall UO,WO,CO
706.80 42.62 Free Outfall UO,WO,CO
706.83 42.78 Free Outfall UO,WO,CO
706.85 42.93 Free Outfall UO,w0,C0
706.88 43.08 Free Outfall U0,W0,C0
706.90 43.22 Free Outfall UO,WO,CO
706.93 43.37 Free Outfall UO,WO,CO
706.95 43.51 Free Outfall UO,WO,CO
706.98 43.65 Free Outfall U0,w0,C0
707.00 43.79 Free Outfall UO,WO,CO
707.03 43.93 Free Outfall UO,WO,CO
707.05 44.06 Free Outfall UO,WO,CO
707.08 44.19 Free Outfall UO,WO,CO
707.10 44.32 Free Outfall UO,WO,CO
707.13 44.46 Free Outfall UO,WO,CO
707.15 44.58 Free Outfall UO,WO,CO
707.18 44.71 Free Outfall U0,w0,C0
707.20 44.83 Free Outfall UO,WO,CO
707.23 44.95 Free Outfall UO,WO,CO
707.25 45.07 Free Outfall U0,w0,C0
707.28 45.19 Free Outfall UO,WO,CO
707.30 45.32 Free Outfall UO,WO,CO
707.33 45.43 Free Outfall U0,w0,C0
707.35 45.56 Free Outfall U0,w0,C0
707.38 45.66 Free Outfall UO,WO,CO
AREA H ROUTING CALCULATIONS APPENDIX J
Page 24 of 35
Type.... Composite Rating Curve Page 4.12
Name.... Out to Creek
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th'set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Title... Project Date: 3/20/2007
Project Engineer: Woolpert
Project Title: Gaston Mall - Predeveloped
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge -------------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------- -------- ----- --------------------------
707.40 45.77 Free Outfall UO,WO,Co
707.43 45.90 Free Outfall UO,WO,CO
707.45 46.00 Free Outfall U0,W0,C0
707.48 46.12 Free Outfall UO1WO,CO
707.50 46.23 Free Outfall UO,WO,CO
707.53 46.35 Free Outfall UO,WO,CO
707.55 46.45 Free Outfall U0,W0,C0
707.58 46.57 Free Outfall U0,W0,C0
_ 707.60 46.67 Free Outfall UO,WO,CO
707.63 46.78 Free Outfall U0,W0,C0
707.65 46.69 Free Outfall UO,WO,CO
'707.68 46.99 Free Outfall U0, inWO, CO
707.70 47.09 Free Outfall UO,WO,CO
707.73 47.20 Free Outfall UO,WO,CO
707.75 47.30 Free Outfall U0,W0,C0
707.78 47.40 Free Outfall U0,W0,C0
707.80 47.51 Free Outfall UO,WO,CO
707.83 47.62 Free Outfall UO,WO,CO
707.85 47.72 Free Outfall U0,W0,C0
707.88 47.81 Free Outfall UO,WO,CO
707.90 47.92 Free Outfall U0,W0,C0
'707.93 48.01 Free Outfall Uo,W0,C0
707.95 48.11 Free Outfall Uo,W0,C0
707.98 48.21 Free Outfall UO,WO,CO
708.00 48.30 Free Outfall Uo,W0,C0
708.03 48.40 Free Outfall UO,WO,CO
708.05 48.50 Free Outfall U0,W0,C0
708.08 48.60 Free Outfall Uo,W0,C0
708.10 48.69 Free Outfall UO,WO,CO
708.13 48.79 Free Outfall UO,Wa,Co
708.15 48.88 Free Outfall UO,WO,.CO
708.18 48.98 Free Outfall UO,WO,CO
708.20 49.07 Free Outfall U0,W0,C0
AREA H ROUTING CALCULATIONS APPENDIX J
Page 25 of 35
Type.... Rational Predev. Peak Q Page 5.01
Name.... PRIMARY SITE Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
SUMMARY OF RATIONAL METHOD PEAK DISCHARGES
--- PREDEVELOPED CONDITIONS ---
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag
----- Freq
------ File
------- IDF Curve

2 Yr
2 ----- ----------------
2 year Gastonia
Tc = .2265 hrs

Tag
Freq
C C adj .-----------------------------.
I C I Area I Peak Q

----- (years)
------ factor
----- ------ 1 final in/hr acres cfs

2 Yr
2
.569 1.000 I-----------------------------I ----------
1 .569 3.9523 20.460 1 46.40
-----------------------------
AREA H ROUTING CALCULATIONS APPENDIX J
Page 26 of 35
Type.... C and Area Page 5.02
Name.... PRIMARY SITE Tag: PRE
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIM_ARY SITE WITH HT AND
MJ FOR ROUTING.PPW
RATIONAL C COEFFICIENT DATA
.................................
............
............
................
--------------------------------- ------------ ------------
Area ----------------
C x Area
Soil/Surface Description
- -------------------------------- C
- acres acres

Predeveloped Portion of the site -------
.2500 ----------
5.028 ----------
1.257
Ex. Developed .8500 10.882 9.250
Harris Teeter / Mary Joes and Parki .2500 4.550 1.138
WEIGHTED C & TOTAL AREA ---> .5691 20.460 11.644
AREA H ROUTING CALCULATIONS APPENDIX J
Page 27 of 35
Type.... Mod. Rational Storm Calcs Page 5.03
Name.... PRIMARY SITE Tag: 2 Yr Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL METHOD
---- Summary for Single Storm Frequency ----
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
RETURN FREQUENCY: 2 yr 'C
-------------------------- ' Adjustment = 1.0
------------------- 00Allowable
------------ Q = 46.40
---------- cfs
---------
Hydrograph Storm Duration, Td = .2000 hrs Tc = .0833 hrs
Hydrograph File: 2 Yr
VOLUMES
Wtd. Adjusted Duration Intens. Area Qpeak I Inflow Storage
'C' 'C' hrs
-------------------------- in/hr acres
----------- cfs 1 ac-ft ac-ft

.861 .861 .0833 --------
5.6396 20.460 --------- --
100.19 I ----------
.690 ---------
.361
.861 .861 .1667 4.4448 20.460 78.96 I 1.088 .468
********** **:***************************:****************** Storage Maximum
.861 .861 .2000 4.1696 20.460 74.07 I 1.224 .483

.861 .861 .2500 3.7600 20.460 66.80 1.380 .458
.861 .861 .3333 3.3667 20.460 59.81 I 1.648 .419
.861 .861 .5000 2.5800 20.460 45.83 1 Qpeak < Qallow
_i
AREA H ROUTING CALCULATIONS APPENDIX J
Page 28 of 35
Type.... Mod. Rational Hyg Page 5.04
Name.... PRIMARY SITE Tag: 2 Yr Event: 2 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 2 year Gastonia Tag: 2 Yr
MODIFIED RATIONAL, METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq
--- File IDF Curve
-- ------ -
2 Yr 2 ----------- ----------------
2 year Gastonia
Td = .2000 hrs
-

Tag Freq ---------------------
C C adj C I -------
Area
Peak Q
(years)
----- ------ - factor final in/hr
---- ------ acres cfs

2 Yr 2 ----------------------
.861 1.000 .861 4.1696
---------------------- -------I
20.460
------- ----------
74.07
HYG file =
HYG ID = PRIMARY SITE
HYG
--- Tag = 2 Yr
-
-
---
-
Peak -
--
-----------------------
Discharge = 74.07 cfs
Time to Peak = .1666 hrs
HYG
---- Volume = 1.224 ac-ft
-------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .08 33 hrs
hrs T
--------- I ----- ime on left represents time for first
------------------ value in each row.

.0000 I -------------------
.00 74.05 74.07 ----------
29.72 ----------
.00
AREA H ROUTING CALCULATIONS APPENDIX J
Page 29 of 35
Type.... C and Area Page 5.05
Name.... PRIMARY SITE Tag: POST
rile.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
RATIONAL C COEFFICIENT DATA
.........................................................................
.........................................................................
-------------------------------------------------------------------------
Area C x Area
Soil/Surface Description C acres acres
-------------------------------- -------- ---------- ----------
Primary Development .8500 15.910 13.524
Harris Teeter / Mary Joes and Parki .9000 4.550 4.095
WEIGHTED C & TOTAL AREA ---> .8611 20.460 17.619
.......................................................................
.......................................................................
AREA H ROUTING CALCULATIONS APPENDIX J -"
Page 30 of 35
Type.... Mod. Rational Storm Calcs Page 5.06
Name.... PRIMARY SITE Tag: 10 Yr Event: 10 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD
---- Summary for Single Storm Frequency ----
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
RETURN FREQUENCY:
----------------- 10 yr 'C' Adjustment = 1.000A1lowable
----------------------------------------- Q = 60.22
---------- cfs
--------
Hydrograph Storm Duration, Td = .2000 hrs Tc = .0833 hrs
Hydrograph File: 10 Yr
: ................. ......... ............ ....... ............. ..................
VOLUMES
Wtd. Adjusted Duration Intens. Area Qpeak I Inflow Storage
'C' 'C' -hrs in/hr acres cfs I ac-ft ac-ft
-----------------
.861 .861 ---------
.0833 ------------
7.1995 --------
20.460 -------- ---
127.90 ----------
.881 --------
.436
.861 .861 .1667 5.7657 20.460 102.43 1.411 .606
**************** *******************:*********************** Storage Maximum
.861 .861 .2000 5.4101 20.460 96.11 1.589 .626

.861 .861 .2500 4.6800 20.460 86.69 1.791 .593
.861 .861 .3333 4.4600 20.460 79.23 2.183 .584
.861 .861 .5000 3.6200 20.460 64.31 2.657 .266
.861 .861 .6667 3.1800 20.460 56.49 Qpeak < Qallow
AREA H ROUTING CALCULATIONS
Page 31 of 35
APPENDIX J
Type.... Mod. Rational Hyg Page 5.07
Name.... PRIMARY SITE Tag: 10 Yr Event: 10 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\
Storm... 10 Year Gastonia Tag: 10 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 / (12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
10 Yr 10 10 Year Gastonia
Td = .2000 hrs
.-----------------------------.
Tag Freq C C adj C I Area Peak Q
(years) factor I final in/hr acres I cfs
----- ------ ----- ------ I-----------------------------I ----------
10 Yr 10 .861 1.000 I .861 5.4101 20.460 I 96.11
-----------------------------
HYG file =
HYG ID = PRIMARY SITE
HYG Tag = 10 Yr
-----------------------------------
Peak Discharge = 96.11 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.589 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
---------I--------------------------------------------------------------
.0000 I .00 96.08 96.11 38.56 .00
AREA H ROUTING CALCULATIONS APPENDIX J
Page 32 of 35
Type.... Mod. Rational Storm Calcs Page 5.08
Name.... PRIMARY SITE Tag: 25 Yr Event: 25 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rational - 4th set of calc's\PRIMARY SITE WITH HT AND
MJ FOR ROUTING.PPW
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD
---- Summary for Single Storm Frequency ----
Q = C--LA * Units Conversion; Where Conversion = 43560 / (1.2 * 3600)
RETURN FREQUENCY: 25 yr 'C' Adjustment = 1.000Allowable Q = 66.79 cfs
----------------------------------------------------------------------------
Hydrograph Storm Duration, Td = .2000 hrs Tc = .0833 hrs
Hydrograph File: 25 Yr
...................
VOLUMES
Wtd. Adjusted Duration Intens. Area Qpeak I Inflow Storage
'C' 'C' hrs in/hr acres cfs ac-ft ac-ft
--------------------------------------------
---------- °--------------------
.861 .861 .0833 8.0394 20.460 142.62 .984 .476
,861 .861 .1667 6.4265 20.460 114.17 1.573 .680
xxxxxxxxxxx k:rxxxxxx**xxx**xxx:rxxxx**xxxxx,rxx**xx*x**xxxxxxx* Storage Maximum
.861 .861 .2000 6.0145 20.460 106.85 1.766 .698
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xxxx**xxxx****xxxx*xxx*xxxx
.861 .861 .2500 5.4000 20.460 95.93 1.962 .655
.861 .861 .3333 4.9400 20.460 87.76 2.418 .645
.861 .861 .5-000 4.0200 20.460 71.41 2.951 .299
.861 .861 .6667 3.5700 20.460 63.42 Qpeak < Qallow
AREA H ROUTING CALCULATIONS APPENDIX J
Page 33 of 35
Type.... Mod. Rational Hyg Page 5.09
Name.... PRIMARY SITE Tag: 25 Yr Event: 25 yr
File.... C:\My Stuff\Gaston Mall Pondpack\Rationai - 4th set of calc's\
Storm... 25 Year Gastonia Tag: 25 Yr
MODIFIED RATIONAL METHOD HYDROGRAPH
Q = CiA * Units Conversion; Where Conversion = 43560 /.(12 * 3600)
Tag Freq File IDF Curve
----- ------ ------------ ----------------
25 Yr 25 25 Year Gastonia
Td = .2000 hrs
-----------------------------
Tag Freq C C adj I C I Area I Peak Q
(years) factor I final in/hr acres cfs
----- ------ ----- ------ I-----------------------------I ----------
25 Yr 25 .861 1.000 I .861 6.0145 20.460 I 106.85
-----------------------------
HYG file =
HYG ID = PRIMARY SITE
HYG Tag = 25 Yr
-----------------------------------
Peak Discharge = 106.85 cfs
Time to Peak = .1666 hrs
HYG Volume = 1.766 ac-ft
-----------------------------------
HYDROGRAPH ORDINATES (cfs)
Time I Output Time increment = .0833 hrs
hrs I Time on left represents time for first value in each row.
--------- I-------------------------------------------------------------
.0000 ( .00 106.81 106.85 42.86 .00
AREA H ROUTING CALCULATIONS APPENDIX J
Page 34 of 35
Appendix A
Index of Starting Page Numbers for ID Names
10 Year Gastonia 10 Yr... 2.01
----- 2 -----
2 year Gastonia 2 Yr... 2.02
25 Year Gastonia 25 Yr... 2.03
----- 5 -----
50 Year Gastonia 50 Yr... 2.04
----- 0 -----
Out to Creek... 4.01
----- P -----
PRIMARY SITE... 5.01, 5.02, 5.03,
5.04, 5.05, 5.06, 5.07, 5.08,
5.09, 3.01, 3.03, 3.05, 3.07
----- W -----
Watershed... 1.01, 1.02
AREA H ROUTING CALCULATIONS
Page 35 of 35
A-1
APPENDIX J
Gaston Mail Redevelopment
Detention / Bioretention Design
Total Drainage Area (Ac.) 4.38 AC
Drainage Area Breakdown (Pre)
Area (AC) C Value
Pervious 438 0.25
Impervious 0 0.9
Drainage Area Breakdown (Post)
Area (AC) C Value
Pervious 0.59 0.25
Impervious 3.79 0.9
Biorention Design
Runoff Volume Determined b
Pre Development
Runoff Volume
Design Storm
Volume Required
/ Simple Method
R, = 0.05 + 0.90 IA
R„ = 0.05
1.D0 (in)
V = 3630 RD*P.v*A
V = 794.97 CF
Post Development
Runoff Volume R„ = 0.05 + 0.90 IA
k = 0.826767
Design Stone 1.00 (n)
Volume Required V = 3630 RD*Rv*A
V = 13176.9 CF
Gastonia 10Yr Rainfall Intensity (in/hr)
Peak Flow. (Pre)
Q = CiA
Q =(436)(7.26)(.25)
Q = 7.95 CFS
Composite C 0.812443
Peak Flow (Pre)
Q = CIA
Q =(4.36)(7.26)(.81)
Q = 25.83 CFS
7.26
Rv = Runoff Coefficient
IA = Impervious Fraction (Impervous Area/Total Area)
V = Volume of Runoff
RD = Design Storm Runoff Depth
A = Drainage Area (AC)
Rv = Runoff Coefficient
IA = Impervious Fraction (Impervous Area/Total Area)
V = Volume of Runoff
RD = Design Storm Runoff Depth
A = Drainage Area (AC)
APPENDIX i<
Gaston Mall Redevelopment
Detention / Bioretention Design
Total Drainage Area (Ac.) 4.38 AC
Drainage Area Breakdown (Pre)
Area (AC) C Value
Pervious 4.38 0.25
Impervious D 0.9
Drainage Area Breakdown (Post)
Area (AC) C Value
Pervious 0.59 D25
Impervious 3.79 0.9
Detention Design
Runoff Volume Determined b,
Pre Development
Runoff Volume
Design Storm
Volume Required
i Simple Method
Rv = O.D5 + 0.90 IA
R„ = 0.05
4.97 (in)
V = 3630 Ro*Rv*A
V = 3951.001 CF
Post Development
Runoff Volume RV = 0.05 + 0.90 IA
R„ = 0.828767
Design Storm 4.97 (in)
Volume Required V = 3630 Ro*Rv*A
V = 65489.19 CF
Amount Required to Detain (Pre - Post)
Storage Volume Required 61538.19 CF
Gastonia 10Yr Rainfall Intensity (in/hr)
Peak Flow (Pre)
Q = CiA
Q =(4.36)(7.26)(.25)
Q = 7.95 CFS
Composite C 0.812443
Peak Flow (Pre)
Q=CiA
Q =(4.36)(726)(.81)
Q = 25.83 CFS
7.26
Rv = Runoff Coefficient
IA = Impervious Fraction (Impervous Areal i otal Area)
NOAA 10YR 24HR Rainfall Depth
V = Volume of Runoff
RD = Design Storm Runoff Depth
A = Drainage Area (AC)
Rv = Runoff Coefficient
IA = Impervious Fraction (Impervous Area/Total Area)
V = Volume of Runoff
RD = Design Storm Runoff Depth
A = Drainage Area (AC)
APPENDIX K
SURFACE WATER
MANAGEMENT REPORT
ADDENDA "A"
GASTON MALL
REDEVELOPMENT PROJECT
NW CORNER OF COX ROAD
AND FRANKLIN BLVD
GASTONIA, NC
PP-GASTON MALL, LLC
February 29, 2008
Woolpert Project No. 064961
ADDENDA A
Overview
An amendment Chapter 14, of the City of Gastonia ("City") Ordinances was made effective February lst
2008. The amendment was promulgated by the North Carolina Environmental Management Commission
in response to the Federal Phase H Stormwater Regulations. The amendment added Division 4,
Management of Post Development Stormwater Runoff.
Computations
A copy of the proposed ordinance referenced above as well as a supplementary manual published by the
City is attached to this addendum for reference. According to the definitions provided, the parking lot
expansion addition and the retail 1 building are considered a "high density project". An excerpt from
Section 14-738(c)(1) provides the water quality standard for high density development as follows:
The measures shall control and treat the difference in the stormwater runoff volume leaving the project site between the
pre- and post- development conditions for, at a minimum, the f rst inch of rain.
i. Treatment volume drawdown time shall be a minimum of 48 hours, but not more than 96 hours.
ii. The measure shall discharge the treatment volume at a rate equal to or less than the pre-development
discharge rate for the one year, 24 hour storm event.
iii. ,411 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 (TSS) from the treatment
volume; any system designed in compliance with the manual shall be considered to have the TSS removal
efficiency indicated in that manual. Treatment" trains" shall be considered to have removal efficiencies
equal to the treatment sum of the various components of the "train ".
Attached to this addendum is an "impervious area map" depicting the areas considered for this analysis.
Area 1 is a portion of the new thru roadway to be constructed. Area 2 is the Retail 1 building, some
associated parking areas and the area set aside for a bio-retention area. Area 3 is a new impervious area
used for parking for Retail 1. The remainder of the site is divided into three categories: Existing
development, Duhart's creek and the adjoining pervious area(s) and future development, which shall be
required to meet the water quality standards at the time of development.
Area 1 is limited in design capacity to meet the City's requirement for water quality due to slope on the
roadway. For that reason, Area 4 shall be used to compensate within the water quality calculation. Said
area is of equal size and contiguous to area 3. Area 4 is currently an existing parking lot servicing the
existing mall.
Runoff from Area 2 is routed to the bio-retention area. The bio-retention area shall be created using fill
meeting having a permeability rate of approximately 2 inches per hour. The location of the bio-retention
is complimentary to Duhart's Creek and the mitigation area encompassing same. According to Chapter
12 of the NC DENR Stormwater BMP manual, the use of bio-retention shall result in a credit of 85%
removal and meeting the peak runoff attenuation.
Runoff from Area 3 and 4 is routed to the underground detention system and shall be treated by the
Stormfilter system located under the parking lot. Refer to the construction plans and section 33 and 3.C
on page 15 and 16 respective of the report for additional information. According to Table 3 on page 15,
the volume of water treated to meet the TSS requirement exceeds the City required minimum. The
system does not meet the treatment volume drawdown minimum of 48 hours. However, it should be
Woolpert, Inc Gaston Mall Redevelopment - Phase II Addenda
January 29, 2008 P.P. Gaston Mall, LLC
Rev February 28, 2008
noted that the drawdown rate is a function of the number of cartridges and available head. Because the
system is a filter-type, not meeting the minimum time requirement should not be construed as a
deficiency.
The table below shows the total flows for the pre and post development conditions for the 1 year storm
event for the combination of area 3 and 4 from the attached impervious area map. A Coefficient of runoff
of 0.25 was used for the existing conditions. The computations were performed using Pondpack by
Haestaed Methods. The output data for the routing analysis is attached to this addendum. The rate of
discharge thru the storm filters is conservatively assumed as 1.67 cfs. (Note: The rate of discharge for
the stormfilter system is roughly 7.48 pm per cartridge for a system having 10 feet of available head.)
Existing Conditions Post-improvement
Discharge Storage Routed Discharge Storage Routed
E (cfs) (Ac-Ft) Stage (ft) (cfs) (Ac-Ft) Stage (ft)
6
64 0.044 774.88 0.67 0.084 774.97
.
The system meets Section 14-738(c)(1)ii of the City ordinance.
G:tSD\Proje \Gaton MaH Rod-iop-t\64961 G-Ma11tF giaeeringl9to DesiptPONDPACY.Vtntiona1-4thse1 ofcalc'stPhM 11 addmda.doe
Woolpert, Inc Gaston Mali Redevelopment- Phase II Addenda 2
January 29, 2008 P.P. Gaston Mall, LLC
Rev February 28, 2008

/
-ld
.2d3F
a
/ LCPER'E
,1 11
jl I 11 lx/) E1 1
-g. FR9fih7.I.N 4V
- EA 1 = 1.47 Acres
- (TO BE COMPENSATED BY AREA 4)
AREA 2 = 4.94 Ames
/
(TO BE ROUTED TO BIO-RETENTION AREA)
- - - - - _
- _ _ _ -_ ,xiEaSTATE es EnSieouNp - - - - - - - ? - - - - -1
LIMITS OF EXISTIN(3-_ ------------------------------------
PARKING LOT ----
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?-?-- -- .- E FP.MPL(,V EL4T ]00' F/IV --.---
- - --------- -----------
d/}}
--------------
AREA 3 = 4.61 Acres
- (TO BE ROUTED THROUGH
UNDERGROUND STORAGE FACILITY)
AREA 4 = 1.47 Acres 0 1 60 320 480
(COMPENSATING FOR AREA 1. TO
BE ROUTED THROUGH
-UNDERGROUND STORAGE FACILITY) NORTy GRAPHIC SCALE IN FEET
CIE.
W
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to
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U'AAUIF Qv Sizing Proposal
STORMWATER
Gaston Mall
Stormwater Treatment System/Design Summary
Gastonia, NC
Information provided:
® Total contributing area = 15.91 acres
® Impervious area = 13.04 acres
Water Quality Volume = 45,489 fe
® Presiding agency = City of Gastonia
Design Requirement:
Provide 85% Total Suspended Solids removal
® Mass load design method
® Design rainfall depth = 1.0"
® Cartridge operating flow rate = 7.5 GPM (36 pound mass load removal capability prior to occlusion)
® Media = Perlite/Zeolite/GAC
i Drop required from inlet to outlet = 18"
Size and cost estimates:
The Stormwater Management StormFilter® is a passive siphon-actuated, flow-through, stormwater
filtration system consisting of a structure that houses rechargeable, media-filled. fitter cartridges. The
StormFilter works by passing stormwater through the media-filled cartridges, which trap particulates
and adsorb pollutants such as dissolved metals, nutrients, and hydrocarbons.
The Volume StormFilter is designed to act as "capture and treat" system. This system will treat the
entire Water Quality Volume (WQv), which is stored upstream of the filter in a pipe detention system.
The system is sized according to the annual mass load method as described in the CONTECN
Stormwater Solutions Inc. design manual. Essentially, this method models the total mass load of TSS,
in pounds, generated from the site on an annualized basis, using the information above. The number
of cartridges required to meet this mass load requirement is then calculated, as a function of the total
mass than can be removed per cartridge prior to required filter changeout.
The StormFilter for this site was sized to provide 102 cartridges in order to meet the mass load
requirement. We can accommodate 102 cartridges using a Box Culvert StormFilter (see attached
drawing). This sizing includes 30% pretreatment with a pretreatment sump that can store 30% of the
annual mass load expected for this site (1997 Ibs in 29 ft3). A 4'x6' vault with 2 foot sump provides this
pretreatment. The StormFilter and pretreatment sump combined are designed to provide 85%
TSS removal, per NC state water quality design requirements. The estimated cost of this system,
complete and delivered to the jobsite, is available upon request. The contractor is responsible for
installing the vault and all external plumbing.
c€) ntechstormwater.com
Mid-Atlantic:
521 Progress Drive, Suite H, Unthicun, MD 21090
Tall-free: 386-740-3318 Fax: [phone]
1123/2008 CONTECH Engineer.MRP
Sizing Summary
Maintenance:
The StormFilter requires regular maintenance to operate effectively. The expected maintenance
interval is 12-18 months, but may vary depending on weather and site conditions. CONTECH
Stormwater Solutions Inc. offers full maintenance services to all of our clients, as well as a cartridge
exchange program to facilitate owner provided maintenance. Please contact CONTECH or navigate to
contechstormwater.com for more information in this regard. if you have any questions or concerns
regarding CONTECH Stormwater Solutions design for this project, please call our Stormwater
Consultant, Jack Moore, at 843.224.1726.
APPENDTA L
StormFilter Sizinci - Water Quality
Project N'arne:
Date: Volume Basest
Gaston Mall
1/17/2008
Input XXX
? Result XXX
SITE CHARACTERISTIC INPUT
Design Storm, P (inches) 1.00
Total Area, AT (acres) 15.911
Impervious Area, A, (acres) 13.04
Water Quality Volume, WQv (cu ft) 45489
Average Rainfall, (inches) 45
Runoff Coefficient, C 0.64
Pretreatment efficiency, (%) ?30%
EMC of 'rSS, (mg/L)* 54.2
ANNUAL MASS LOAD CALCULATIONS
Annual Mass Load, (Ibs) 6,659
Requires! Filter Efficiency, (/a) 0.79 /.
Avow
Allowable Load per Cartridge, (Ibs) 36 _
,"

Number of Cartridges Required
1t12 ....
T RMATER .
SYSTEM DESIGN
Vault Size P)OX cuivert
D>
-o
m
z
0
r
TS-0037
Detention Summary
Proiect Name:
Date:
Gaston Mail
1/23/2008
Stgmge Requirement
Water Quality Volume, WQv (cf) 45480
Required WQV storage (75% WQV) (cf) 34117
Ripe Length
Storage provided in 266' of 48" pipe (cf) 3343
Storage provided in 2,500' of 60" pipe (cf) 40087
Invert of detention system 701.5'
Water Quality Storage
WQV Depth in 60" and 48" 2.02'
Water Quality Volume water surface elevation 704.42'
WQV storage provided in Box Culvert StormFilter (cf) 1783
Storage in 60" and 48" pip below elevation 704.42' (cf) 32330

Summary ?"MMI
Total WQV storage (cf) 34122
STRMATE
"
°
"
Total storage (cf) 54213 mo
°
?
{
I
]
-Q
m
z
r
TS-BO37
u VIE AM U101
PRELIMINARY
m = = " NOT APPROVED FOR
FABRICATION OR CONSTRUCTION
STORMWATER
?- SOLUTIONS INC.
6u" UNDERGROUND DETENTION SYSTEM
GASTON MALL REDEVELOPMENT

2
1
0 1-24-08 PRELIMINARY / PROPOSAL DRAWINGS KJW
N0. DA7E DESCRIPTION DRAWN BY APPROVED BY
THE UNDERSIGNED HEREBY APPROVES THE ATTACHED (5) PAGES.
CUSTOMER DATE---
NOTES:
1) ALL ELEVATIONS, DIMENSIONS AND LOCATIONS OF RISERS AND INLETS,
SHALL. BE VERIFIED BY THE ENGINEER PRIOR TO RELEASING FOR
FABRICATION.
2) IN SITUATIONS WHERE A FINE-GRAINED BACKFILL MATERIAL IS USED
ADJACENT TO THE PIPE SYSTEM, AND ESPECIALLY IN SITUATIONS
INVOLVING HIGH GROUNDWATER TABLES, CONSIDERATION SHOULD BE
GIVEN TO THE USE OF GASKETED PIPE JOINTS. AT THE VERY LEAST,
THE PIPE JOINTS SHOULD BE WRAPPED IN A SUITABLE, NON-WOVEN
GEOTEXTILE FABRIC TO PREVENT INFILTRATION OF FINES INTO THE
PIPE SYSTEM.
3) ALL FITTINGS AND REINFORCEMENT COMPLY WITH ASTMM A998.
4) SYSTEM MADE FROM: 60" 0, 5".1", ALT2, 14gD., CSP.
5) MINIMUM COVER HEIGHT FOR PIPE DESCRIBED IN NOTE #4 IS 12".
6) CONSIDERATIONS FOR CONSTRUCTION EQUIPMENT LOADS MUST BE
TAKEN IIJTO ACCOUNT. SEE DETAIL 3, PAGE P5.
7) ALL PIPE DIMENSIONS ARE SUBJECT TO MANUFACTURERS
TOLERANCES.
8) ALL RISERS AND STUBS ARE 2 2/y" X Y2" CORRUGATION AND 16 GAGE,
UNLESS OTHERWISE NOTED.
9) RISERS TO BE FIELD TRIMMED TO FINAL GRADE, MAY BE FITTED WITH
LADDER OR STEPS AS REQUIRED BY ENGINEER OF RECORD. FOR
TYPICAL MANHOLE DETAIL, SEE DETAIL 4, PAGE P5.
10) SYSTEM IS DESIGNED FOR H2O AND H25 LOADING.
GASTONIA, NC
INDEX:
P1 COVER SHEET
P2-P3 PRELIMINARY LAYOUT
P4-P5CONSTRUCTION DETAILS
SPECIFICATION FOR CORRUGATED STEEL PIPE-ALUMINIZED TYPE 2 STEEL:
SCOPE
THIS SPECIFICATION COVERS THE MANUFACTURE AND INSTALLATION OF THE
CORRUGATED STEEL PIPE (CSP) DETAILED IN THE PROJECT PLANS.
MATERIAL
THE ALUMINIZED TYPE 2 STEEL COILS SHALL CONFORM TO THE APPLICABLE
REQUIREMENTS OF AASHTO M 274 OR ASTM A 929.
EEL
THE CSP SHALL BE MANUFACTURED IN ACCORDANCE WITH THE APPLICABLE
REQUIREMENTS OF AASHTO M-36 OR ASTM A750. THE PIPE SIZES,
GAUGES AND CORRUGATIONS SHALL BE AS SHOWN ON THE PROJECT
PLANS.
ALL FABRICATION OF THE PRODUCT SHALL OCCUR WITHIN THE
UNITED STATES.
HANDLING & ASSEMBLY
SHALL BE IN ACCORDANCE WITH NCSPA'S (NATIONAL CORRUGATED STEEL
PIPE ASSOCIATION) RECOMMENDATIONS.
INSTALLATION
SHALL BE IN ACCORDANCE WITH AASHTO STANDARD SPECIFICATIONS FOR
HIGHWAY BRIDGES, SECTION 26, DIVISION II OR ASTM A 798 AND IN
CONFORMANCE WITH THE PROJECT PLANS AND SPECIFICATIONS. IF THERE
ARE ANY INCONSISTENCIES OR CONFLICTS THE CONTRACTOR SHOULD
DISCUSS AND RESOLVE WITH THE PROJECT ENGINEER.
IT IS ALWAYS THE CONTRACTOR'S RESPONSIBILITY TO FOLLOW OSHA
GUIDELINES FOR SAFE PRACTICES.
CONSTRUCTION LOADS
CONSTRUCTION LOADS MAY BE HIGHER THAN FINAL LOADS. FOLLOW THE
MANUFACTURER'S OR NCSPA GUIDELINES.
NOTE:
1. LOCATION OF ALL MANHOLES, STUBS, INLETS,
OUTLETS AND OUTLET CONTROL STRUCTURES, TO
BE SPECIFIED 3Y PROJECT ENGINEER OF RECORD
PRIOR TO FABRICATION.
2. ALL RECOMMENDED REINFORCING ON THE SYSTEM
WILL BE DESIGNED BY MANUFACTURER TO CONFORM
TO ASTM A998 AFTER PURCHASE ORDER IS ISSUED.
INSTALLATION SPECIFICATON_
PRE-CONSTRUCTION MEETING
PRIOR TO INSTALLATION OF THE DETENTION SYSTEM A PRE-CONSTRUCTION
MEETING SHALL BE CONDUCTED. THOSE REQUIRED TO ATTEND ARE THE
SUPPLIER OF THE DETEN110N SYSTEM, THE GENERAL CONTRACTOR, SUB
CONTRACTORS AND THE ENGINEER.
FOUNDATION /BEDDING PREPARATION
PRIOR TO PLACING THE BEDDING, THE FOUNDATION MUST BE CONSTRUCTED TO
A UNIFORM AND STABLE GRADE. IN THE EVEIJT THAT UNSUITABLE FOUNDATION
MATERIALS ARE ENCOUNTERED DURING EXCAVATION, THEY SHALL BE REMOVED
AND BROUGHT BACK TO THE GRADE W T}i A FILL MATERIAL AS APPROVED BY
THE ENGINEER. ONCE THE FOUNDATION PREPARATION IS COMPLETE, THE
4 INCHES OF A WELL-GRADED GRANULAR MATERIAL SHALL BE PLACED AS THE
BEDDING.
BACKFILL
THE BACKFILL SHALL BE AN Al. A2 OR A3 GRANULAR FILL PER AASHTO IA-145
OR A WELL-GRADED GRANULAR FILL AS APPROVED BY THE ENGINEER (SEE
INSTALLATION GUIDELINES). THE MATERIAL SHALL BE PLACED IN 8-INCH LOOSE
LIFTS AND COMPACTED TO 909, AASHTO T99 STANDARD PROCTOR DENSITY.
WHEN PLACING THE FIRST LIFTS OF BACKFILL IT IS IMPORTANT TO MAKE SURE
THAT THE BACKFILL IS PROPERLY COMPACTED UNDER AND AROUND THE PIPE
HAUNCHES. BACKFILL SHALL BE PLACED SUCH THAT THERE IS NO MORE THAN
A TWO LIFT DIFFERENTIAL BETWEEN ANY OF THE PIPES AT ANY TIME DURING
THE BACKFILL PROCESS. THE BACKFILL SHALL BE ADVANCED ALONG THE
LENGTH OF THE DETENTION SYSTEM AT THE SAME RATE TO AVOID DIFFERENTIAL
LOADING ON THE PIPE.
OTHER ALTERNATE BACKFILL MATERIAL MAY BE ALLOWED DEPENDING ON SITE
SPECIFIC CONDITIONS. REFER TO TYPICAL BACKFILL DETAIL WITHIN THIS SET
OF PLANS FOR TYPE OF MATERIAL REQUIRED.
MINIMUM COVER
BACKFILL SHALL BE PLACED TO THE PROPER ELEVATION OVER THE SYSTEM AS
OUTLINED IN THE PLANS. MINIMUM COVER FOR CONSTRUCTION LOADING NEEDS
TO BE DETERMINED BASED ON THE TYPE OF EQUIPMENT THAT IS PLANNED FOR
CONSTRUCTION. PROPER COVER FOR CONSTRUCTION EQUIPMENT SHALL BE
DETERMINED PRIOR TO ]HE PRE-CONSTRUCTION MEETING BY THE ENGINEER.
CONTECH PROJECT ID # 3D984
3D" GRATE
INLET RISER
RIM = 709.00'
INV = 701.50'
15" STUB
INV = 705. DO'S
REINFORCED BULKHEAD
OUTLET CONTROL (TYP. OF 6)
STRUCTURE 30" STUB
WEIR ELEV. = 704.42' IIJV = 701.50'
24" STUB, 15" STUB
INV = 701.5 INV = 701.5
BOX CULVERT
STORMFILTER WITH
102 CARTRIDGES
4'X6' PRETREATMENT
VAULT W/ 2'-0" SUMP
120'-9"
36" RISER
-0" RIM = 71D.D0'
i INV = 701.50'
- - -36" RISER
3-4 RIM = 710.D0'
INV = 7D1.5D'
46" CIAP
INV = 701.50'
CONNECTS TO
DRAINAGE SYSTEM
-FULL LENGTH NOT SHOWN
18" STUB
INV = 705.00'
30' GRATE 30' GRATE `o
-9" INLET RISER INLET RISER 103'-3"
I RIM = 700' RIM = 70.00'
INV = 7011..50' IIJV = 701.SD'? ,
1B" STUB
390'-6" INV = 705.00'
HUGGER BAND 30" TRANSFER PIPE 35" RISER
SEE DETAIL INV = 701.50' RIM - 710.00
P3 (TYP OF 5) INV = 701.SD' 10'-6"
0
I
To
0
P3 18" STUB
36" RISER INV = 705.00'
RIM = 710.00' _
INV = 701.50'
24" STUB `?18" STUB 10'-6"
INV = 7D1.90' IIJV = 705.00'
PRELIMINARY LAYOUT
PRELIMINARY
NOT APPROVED FOR
FABRICATION OR CONSTRUCTION
3

1
0 1-24-08 PRELIMINARY / PROPOSAL DRAWMGS KJW
110. DATE _ DESCRIPTION DRAWN 6Y APPROVED BY
SCALE : 1"=35'
STORAGE VOLUME PROVIDED = 52430 C.F.
NOTE:
1, LOCATION OF ALL MANHOLES, STUBS, INLETS,
OUTLETS AND OUTLET CONTROL STRUCTURES, TO
BE SPECIFIED BY PROJECT ENGINEER OF RECORD
PRIOR TO FABRICATION.
2. ALL RECOMMENDED REINFORCING ON THE SYSTEM
WILL BE DESIGNED BY MANUFACTURER TO CONFORM
TO ASTM A998 AFTER PURCHASE ORDER IS ISSUED. STORMW
aozs
TED = TO BE DETERMINED CONTECH IDS 30984
NOTFS;
PIPE IS 6D"; ALT2; 14GA.; 5"x1"
PIPE IS 4B"; ALT2; 14GA.; 2 2/3"X1/2"
SPACING BETWEEN PIPES 15 2'-6"
p @?/{ SYSTEM INVERT IS 7D1.50"
IRELIMINAI tl LAYOUT
60" UNDERGROUND DETENTION SYSTEM
GASTON MALL REDEVELOPMIENT
GASTONIA. NC sHep? T.,
640'-0"
ULTRAFLO CULVERT LAYOUT
SCALE : 1" = 50'
PRELIMINARY
NOT APPROVED FOR
FABRICATION OR CONSTRUCTION
3
z
1
D 1-24-08 PRELIMINARY /PROPOSAL ORAMNGS KJW
NO. DATE DESCRIPTION DRAWN BY APPROVE. BY
NOTE:
1. LOCATION OF ALL MANHOLES, STUBS, INLETS,
OUTLETS AND OUTLET CONTROL STRUCTURES, TO
BE SPECIFIED BY PROJECT ENGINEER OF RECORD
PRIOR TO FABRICATION.
2. ALL RECOMMENDED REINFORCING ON THE SYSTEM
WILL BE DESIGNED BY MANUFACTURER TO CONFORM
TO ASTM A998 AFTER PURCHASE ORDER IS ISSUED.
TBD = TO BE DETERMINED
NOTES:
PIPE IS 72"; ALT2; ULTRAFLO; 12GA.
SPACING BETWEEN PIPES IS 3'-0'
SYSTEM INVERT IS 701.00"
60" UNDERGROUND DETENTION SYSTEM
GASTON MALL REDEVELOPMENT "eY
GASTONIA, NC ."EP3 OF S
12-1 /8"
10'
0-RING H-12 HUGGER
GASKET BAND
T, BAR & STRAP O-RING GASKET
NECTOR
E)
GI
3.) NORMAL ROADWAY EMBANKMENT FILL
PLACED IN 8" LIFTS AND COMPACTED
TO MIN. 90% STANDARD DENSITY PER
AASHTO T-99.
4.) 12" MIN. FOR DIAMETERS THROUGH 96"
18" MIN. FOR DIAMETERS FROM 102"
TO 144" DISTANCE IS MEASURED FROM
TOP OF PIPE TO TOP OF RIGID
PAVEMENT OR BOTTOM OF FLEXIBLE
PAVEMENT.
5.) WELL-GRADED GRANULAR FILL MATERIAL
FROM SPRINGLINE UP. TO BE COMPACTED
TO MIN. 90% STANDARD DENSITY PER
AASHTO T-99.)
6.) 12"0 THRU 84"0 2 2/3" X 1/2"
CSP, GAGE PER AASHTO SECTION 12.
REFER TO PROJECT DRAWINGS.
8.) STANDARD SPACING IN TABLE, SPECIAL
SPACING IS SUBJECT TO APPROVAL BY
CONTECH CONSTRUCTION PRODUCTS INC.
SPACING CHART PER AISI
AND NCSPA GUIDELINES
DIAMETER REQUIRED SPACING
UP TO 24
"
1 12
24" - 72
"
1/2 PIPE DIA
72" AND UP 36"
9.) CONTECH C4D NON-WOVEN GEOTEXTILE AS
REQUIRED TO PREVENT SOIL MIGRATION.
10.) RELATIVELY LOOSE GRANULAR BEDDING,
ROUGHLY SHAPED TO FIT THE BOTTOM OF
THE PIPE, FROM SPRINGLINE OF PIPE TO
4"-6" BELOW BOTTOM OF PIPE. (STONE
OR OTHER SUITABLE GRANULAR MATERIAL).
TYPICAL BACKFILL DETAIL
P4 SCALE: N.T.S.
PRELIMINARY
NOT APPROVED FOR
FABRICATION OR CONSTRUCTION
3

1
0 1-24-08 PRELIMINARY / PROPOSAL DRAWINGS KJW
NO. DATE DESCRIPT m DRAWN BY APPROVED BY
NOTE:
1. LOCATION OF ALL MANHOLES, STUBS, INLETS,
OUTLETS AND OUTLET CONTROL STRUCTURES, TO
BE SPECIFIED BY PROJECT ENGINEER OF RECORD
PRIOR TO FABRICATION.
2. ALL RECOMMENDED REINFORCING ON THE SYSTEM
WILL BE DESIGNED BY MANUFACTURER TO CONFORM
TO ASTM A998 AFTER PURCHASE ORDER IS ISSUED.
TBD = TO BE DETERMINED CONTECHID9 30984
NCH
60" UNDERGROUND DETENTION SYSTEM
GASTON MALL REDEVELOPMENT
caSTnldtO we zNEOa na s
"0 BAR H-12
HUGGER
"0 BOLT
1 3/B" THK. 7"
WIDE FLAT
NEOPRENE GASKET
FLAT GASKET
H-12 HUGGER
BAND
NO GASKET
GASKETED
SECTION
GENERAL NOTES
'
1. REFER TO CONTECH BAND SELECTION GUIDE FOR BAND WIDTH, GAGE, AND FASTENER
TYPES.
2. BANDS FOR PIPE-ARCH ARE THE SAME AS FOR EQUIVALE14T DIAMETER ROUND PIPE.
3. BANDS ARE NORMALLY FURNISHED AS FOLLOWS:
12" THRU 48" 1-PIECE
54" THRU 96" 2-PIECE
102" THRU 144" 3-PIECES.
4. BAND FASTENERS ARE ATTACHED WITH SPOT WELDS, RIVETS OR HAND WELDS. ALL
ALUMINUM BANDS, BOTH SINGLE AND DOUBLE BB&S, ARE FURNISHED WITH A
14 GAGE ALUMINUM BACK-UP PLATE WELDED TO THE BAND AND THE STRAP.
5. REROLLED ANNULAR END CORRUGATIONS ARE NORMALLY 2-2/3" X 1/2".
6. DIMENSIONS ARE SUBJECT TO MANUFACTURING TOLERANCES.
7. ORDER SHALL DESIGNATE GASKET OPTION.
2 H-12 HUGGER BAND DETAIL
P4 SCALE: N.T.S.
1.) RIGID OR FLEXIBLE PAVEMENT 7.) 54"0 THRU 144"0 3" X 1" OR 5" X 1" CSP
GAGE PER AASHTO SECTION 12.
2.) GRANULAR ROAD BASE REFER TO PROJECT DRAWINGS.
CONNECTION DETAIL
SINGLE
BOLT. BAR & STRAP
Z
0
°
TRAFFIC RATED MANHOLE
? N OR CATCH BASIN (BY
} o

11: 0 CONTRACTOR)
GRATE FRAME INSIDE
?-'
Z C)
a
VEHICULAR WEARING SURFACE
DIAMETER SHOULD
o (BY CONTRACTOR) EQUAL APPROXIMATELY
a
w
(RISER 0+ 3")
o o
rFINISHED GRADE a m
i
!I SIZE, REINFORCING
COMPACTED BY ENGINEER
SUB GRADE
CUT RISER TO FINAL CMP RISER BASE COLLAR/SLAB
ELEVATION IN FIELD
(BY CONTRACTOR)
CONSTRUCTION LOADS:
FOR TEMPORARY CONSTRUCTION VEHICLE LOADS, AN EXTRA AMOUNT OF COMPACTED COVER MAY BE REQUIRED OVER THE TOP
OF THE PIPE. THE HEIGHT-OF-COVER SHALL MEET THE MINIMUM REQUIREMENTS SHOWN IN THE TABLE BELOW. THE USE OF
HEAVY CONSTRUCTION EQUIPMENT NECESSITATES GREATER PROTECTION FOR THE PIPE THAN FINISHED GRADE COVER MINIMUMS
FOR NORMAL HIGHWAY TRAFFIC.

PIPE SPAN AXLE LOADS (kips)
INCHES
16-50 50-75 75-110110-15
MI NIMUM C OVER (F T
12-42 2.0 2.5 3.0 3.0
48-72 3.0 3.0 3.5 4.0
78-120 3.0 3.5 4.0 4.0
126-144 3.5 4.0 4.5 4.5
'MINIMUM COVER MAY VARY, DEPENDING ON LOCAL CONDITIONS. THE CONTRACTOR MUST PROVIDE THE ADDITIONAL COVER REQUIRED TO
AVOID DAMAGE TO THE PIPE. MINIMUM COVER IS MEASURED FROM THE TOP OF THE PIPE TO THE TOP OF THE MAINTAINED CONSTRUCTION
ROADWAY SURFACE.
(-3--? CONSTRUCTION LOADING DIAGRAM
P5 SCALE: N.T.S.
PRELIMINARY
NOT APPROVED FOR
FABRICATION OR CONSTRUCTION
3
2
i
0 1-24-08 PRELIMINARY / PROPOSAL DRAWINGS KJW
140. DATE DESCRIPTION DRAWN BY APPROVED BY
NOTE:
1. LOCATION OF ALL MANHOLES, STUBS, INLETS,
OUTLETS AND OUTLET CONTROL STRUCTURES, TO
BE SPECIFIED BY PROJECT ENGINEER OF RECORD
PRIOR TO FABRICATION.
2. ALL RECOMMENDED REINFORCING ON THE SYSTEM
WILL BE DESIGNED BY MANUFACTURER TO CONFORM
TO ASTM A998 AFTER PURCHASE ORDER IS ISSUED.
TBD = TO BE DETERMINED _ CONTECHID# 30994
ACCESS LADDER--/
(BY MANUFACTURER)
SECTION AA
A-A
USE FLEXIBLE JOINT
MATERIAL TO PREVENT
CONCRETE FROM
CONTACTING THE
RISER IN ANY WAY
REINFORCED CONCRETE MANHOLE
NOTES: CAP DESIGNED BY ENGINEER
1. THE CONCRETE CAP SHALL BE SIZED AND DESIGNED BY OTHERS
SO THAT THE LOADS ARE TRANSMITTED TO THE SOIL, AND NOT
THE RISER.
2. THE CONCRETE CAP SHALL BE SIZED TO PROVIDE AN ADEQUATE
BOTTOM AREA BASED 014 THE ALLOWABLE BEARING CAPACITY
OF THE SOIL.
3. THE FLEXIBLE JOINT MATERIAL (RECYCLED VINYL OR EQ.) TO BE
STIFF ENOUGH SO THAT THE CONCRETE CAN NEVER ENGAGE
WITH THE RISER CORRUGATIONS.
MANHOLE CAP DETAIL
P5 SCALE: N.T.S.
60" UNDERGROUND DETENTION SYSTEM
GAST014 MALL REDEVELOPMENT
GASTONIA, NC PI 50F5
LN 18,
STORMWATER
The Storrnwater
Operation and Maintenance
Management StormFilter®
Vault, Cast-In-Place, and Linear Units
Important. These guidelines should be used
as a part of your site stormwa ter
management plan.
Description
The Stormwater Management StormFilter®
(StormFilter) is a passive, flow-through,
stormwater filtration system. The system is
comprised of one or more vaults that house
rechargeable, media-filled, filter cartridges.
The StormFilter works by passing
stormwater through the media-filled
cartridges, which trap particulates and
adsorb materials such as dissolved metals
and hydrocarbons. Once filtered through the
media, the treated stormwater is directed to
a collection pipe or discharged into an open
channel drainage way.
The StormFilter is offered in multiple
configurations, including vault, linear, catch
basin, manhole, and cast-in-place. The
vault, linear, manhole, and catch basin
models utilize pre-manufactured units to
ease the design and installation processes.
The cast-in-place units are customized for
larger flows and may be either covered or
uncovered underground units.
Purpose
The StormFilter is a passive, flow-through,
stormwater filtration system designed to
improve the quality of stormwater runoff
from the urban environment before it enters
receiving waterways. It is intended to
function as a Best Management Practice
(BMP) to meet federal, state, and local
requirements for treating runoff in
compliance with the Clean Water Act.
Through independent third party studies, it
has been demonstrated that the StormFilter
is highly effective for "treatment of first flush
flows and for treatment of flow-paced flows
during the latter part of a storm. In general,
the StormFilter's efficiency is highest when
pollutant concentrations are highest. The
primary non-point source pollutants targeted
for removal by the StormFilter are:
suspended solids (TSS), oil and grease,
soluble metals, nutrients, organics, and
trash and debris.
Sizing
The StormFilter is sized to treat the peak
flow of a water quality design storm. The
peak flow is determined from calculations
based on the contributing watershed
hydrology and from a design storm
magnitude set by the local stormwater
management agency. The particular size of
a StormFilter unit is determined by the
number of filter cartridges (see Figure 1)
required to treat this peak flow.
The flow rate through each filter cartridge is
adjustable, allowing control over the amount
of contact time between the influent and the
filter media. The maximum flow rate
through each cartridge can be adjusted to
between 5 and 15 gpm using a calibrated
restrictor disc at the base of each filter
cartridge. Adjustments to the cartridge flow
rate will affect the number of cartridges
required to treat the peak flow.
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Basic Function
The StormFilter is designed to siphon
stormwater runoff through a filter cartridge
containing media. A variety of filter media is
available and can be customized for each
site to target and remove the desired levels
of sediments, dissolved phosphorus,
dissolved metals, organics, and oil and
grease. In many cases, a combination of
media is recommended to maximize the
effectiveness of the stormwater pollutant
removal.

Figure 1. The StormFilter Cartridge
Priming System Function
When stormwater in the StormFilter unit
enters a StormFilter cartridge, it percolates
horizontally through the cartridge's filter
media and collects in the center tube of the
cartridge, where the float in the cartridge is
in a closed (downward) position.
Water continues to pass through the filter
media and into the cartridge's center tube.
The air in the cartridge is displaced by the
water and purged from beneath the filter
hood through the one-way check valve
located in the cap. Once the center tube is
gilled with water (approximately 18 inches
deep), there is enough buoyant force on the
float to open the float valve and allow the
treated water in the center tube to flow into
the under-drain manifold. This cause's the
check valve to close, initiating a siphon that
draws polluted water throughout the full
surface area and volume of the filter. Thus,
the entire filter cartridge is used to filter
water throughout the duration of the storm,
regardless of the water surface elevation in
the unit. This siphon continues until the
water surface elevation drops to the
elevation of the hood's scrubbing
regulators.
The cartridges are connected to the under-
drain manifold with a plastic connector.
Since some media used is potentially
buoyant, a threaded connector affixed to the
under-drain manifold (with glue or other
adhesive) is necessary to ensure that the
cartridge isn't lifted out of place. For the
heavier compost media, a slip connector is
used.
The StormFilter is also equipped with flow
spreaders that trap floating debris and
surface films, even during overflow
conditions. Depending on individual site
characteristics, some systems are equipped
with high and/or base flow bypasses. High
flow bypasses are installed when the
calculated peak storm event generates a
flow that overcomes the overflow capacity of
the system. This is especially important for
precast systems. Base flow bypasses are
sometimes installed to bypass continuous
inflows caused by ground water seepage,
which usually do not require treatment. All
StormFilter units are designed with an
overflow. The overflow operates when the
inflow rate is greater than the treatment
capacity of the filter cartridges.
©2006 CONTECH Stormwater Solutions Toll-free: 800.548.466.7 2 of 9
contechstormwater.com Vault, CI? and Linear StormFilter Operation and Maintenance Guidelines
Maintenance Guidelines
The primary purpose of the StormFilter is to
filter out and prevent pollutants from
entering our waterways. Like any effective
filtration system, periodically these
pollutants must be removed to restore the
StormFilter to its full efficiency and
effectiveness.
Maintenance requirements and frequency
are dependent on the pollutant load
characteristics of each site.
Maintenance activities may be required in
the event of a chemical spill or due to
excessive sediment loading from site
erosion or extreme storms. It is also good
practice to inspect the system after severe
storm events.
Types of Maintenance
Presently, procedures have been developed
for two levels of maintenance:
a inspection/minor maintenance
® Major maintenance.
Inspection/minor maintenance activities are
combined since minor maintenance does
not require special equipment and typically
little or no materials are in need of disposal.
Inspection/minor maintenance typically
involves:
a Inspection of the vault itself
® Removal of vegetation and
trash and debris.
Major maintenance typically includes:
a Cartridge replacement
Sediment removal
Important: Applicable safety (OSHA) and
disposal regulations should be followed
during all maintenance activities.
Two scheduled inspections/maintenance
activities should take place during the year.
First, an inspection/minor maintenance
activity should be done. During the minor
maintenance activity (routine inspection,
debris removal), the need for major
maintenance should be determined and, if
disposal during major maintenance will be
required, samples of the sediments and
media should be obtained.
Second, if required, a major maintenance
activity (replacement of the filter cartridges
and associated sediment removal) should
be performed.
In addition to these two scheduled activities,
it is important to check the condition of the
StormFilter unit after major storms for
damage caused by high flows and for high
sediment accumulation that may be caused
by localized erosion in the drainage area. It
may be necessary to adjust the
maintenance activity schedule depending
on the actual operating conditions
encountered by the system.
In general, minor maintenance activities will
occur late in the rainy season, and major
maintenance will occur in late summer to
early fall when flows into the system are not
likely to be present.
Maintenance Activity Frequency
The primary factor controlling timing of
maintenance for the StormFilter is
sedimentation.
Maintenance Activity Timing
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contechstormwater.com Vault, CIP and Linear StormFiiter Operation and Maintenance Guidelines
A properly functioning system will remove
solids from water by trapping particulates in
the porous structure of the filter media. The
flow through the system will naturally
decrease as more and more solids are
trapped. Eventually the flow through the
system will be low enough to require
replacement of the cartridges. It may be
possible to extend the usable span of the
cartridges by removing sediment from
upstream trapping devices on an as-needed
basis in order to prevent material from being
re-suspended and discharged to the
system.
Site conditions greatly influence
maintenance requirements. StormFilter
units located in areas with erosion or active
construction should be inspected and
maintained more often than those in fully
stabilized areas.
The maintenance frequency may be
adjusted as additional monitoring
information becomes available during the
inspection program. Areas that develop
known problems should be inspected more
frequently than areas that demonstrate no
problems, particularly after large storms.
Ultimately, inspection and maintenance
activities should be scheduled based on the
historic records and characteristics of an
individual StormFilter system. It is
recommended that the maintenance agency
develop a database to properly manage
StormFilter maintenance programs.
Prior to the development of the
maintenance database, the following
maintenance frequencies should be
followed:
Inspection/minor maintenance
• Onetime per year
• After Major Storms
Major maintenance
One time per year
In the event of a chemical spill
Frequencies should be updated as required.
The recommended initial frequency for
inspection/minor maintenance is two times
per year for precast units. StormFilter units
should be inspected after all major storms.
Sediment removal and cartridge
replacement on an annual basis is
recommended until further knowledge is
gained about a particular system.
Once an understanding of site
characteristics has been established,
maintenance may not be needed for one to
two years, but inspection is warranted.
Maintenance Methods
InspectionlMinor Maintenance
The primary goal of a maintenance
inspection is to assess the condition of the
cartridges relative to the level of sediment
loading. It may be desirable to conduct this
inspection during a storm to observe the
relative flow through the filter cartridges. If
the submerged cartridges are severely
plugged, large amounts of sediments will be
present and very little flow will be
discharged from the drainage pipes. If this
is the case, it is likely that the cartridges
need to be replaced.
Warning: In the case of a spill, the worker
should abort maintenance activities until the
proper guidance is obtained. Notify the
local hazard control agency and CONTECH
Stormwater Solutions immediately.
To conduct an inspection and/or minor
maintenance:
Important: Maintenance must be performed
by a utility worker familiar with StormFilter
u n its.
1. If applicable, set up safety equipment to
protect pedestrians from fall hazards
due to open vault doors or when work is
being done near walkways or roadways.
2. Visually inspect the external condition of
the unit and take notes concerning
defects/problems.
©2006 CONTECH Stonwater Solutions Toll-tee: 800.548.4667 4 of 9
contechstormwater.com Vault, CiP and Linear StormFilter Operation and Maintenance Guidelines
Important: This activity will require that
workers enter the vault to remove the
cartridges from the drainage system.
Method 1:
a. Using an appropriate sling, attach
the cable from the boom, crane, or
tripod to the cartridge being
removed. Contact CONTECH
Stormwater Solutions for
specifications on appropriate
attachment devices.
This activity will require that workers
enter the vault to remove the
cartridges from the drainage system
and place them under the vault
opening for lifting.
Important: Note that cartridges
containing media other than the leaf
media require unscrewing from their
threaded connectors. Take care not
to damage the manifold connectors.
This connector should remain
installed in the manifold and capped
if necessary.
b. Remove the used cartridges
(250 lbs. each). from the vault.
Important: Care must be used to
avoid damaging the cartridges
during removal and installation. The
cost of repairing components
damaged during maintenance will be
the responsibility of the owner
unless CONTECH Stormwater
Solutions performs the maintenance
activities and damage is not related
to discharges to the system.
c. Set the used cartridge aside or
load onto the hauling truck.
d. Continue steps a through c until
all cartridges have been removed.
Method 2:
a. Unscrew the cartridge cap.
b. Remove the cartridge hood.
c. Tip the cartridge on its side.
Important: Note that cartridges
containing media other than the leaf
media require unscrewing from their
threaded connectors. Take care not
to damage the manifold connectors.
This connector should remain
installed in the manifold and capped
if necessary.
d. Empty the cartridge onto the vault
floor.
e. Set the empty, used cartridge
aside or load onto the hauling truck.
f. Continue steps a through e until
all cartridges have been removed.
9. Remove deposited sediment from the
floor of the vault and, if large amounts
are present, from the forebay. This can
usually be accomplished by shoveling
the sediment into containers, which,
once full, are lifted mechanically from
the vault and placed onto the hauling
truck. If Method 2 in Step 8 is used to
empty the cartridges, or in cases of
extreme sediment loading, a vactor
truck may be required.
10. Once the sediments are removed,
assess the condition of the vault and the
condition of the manifold and
connectors. The connectors are short
sections of 2-inch schedule 40 PVC, or
threaded schedule 80 PVC that should
protrude above the floor of the vault.
a. If required, apply a light coating of
FDA approved silicon grease to the
outside of the exposed portion of
the connectors. This ensures a
watertight connection between the
cartridge and the drainage pipe.
b. Replace any damaged connectors.
11. Using the boom, crane, or tripod, lower
and install the new cartridges. Once
9)2006 CONTECH Stormwater Solutions Tolkiree: 800.548.4667 6 of 9
contechstormwateccom Vault, CIP and Linear StormFlter Operation and Maintenance Guidelines
again, take care not to damage
connections.
12. Close and. fasten the door.
13. Remove safety equipment.
14. Make notes about the local drainage
area relative to ongoing construction,
erosion problems, or high loadings of
other materials to the system.
15. Finally, dispose of the residual materials
in accordance with applicable
regulations. Make arrangements to
return the used cartridges to CONTECH
Stormwater Solutions.
Related Maintenance Activities
(Performed on an as-needed basis)
StormFilter units are often just one of many
components in a more comprehensive
stormwater drainage and treatment system.
The entire system may include catch
basins, detention vaults, sedimentation
vaults and manholes, detention/retention
ponds, swales, artificial wetlands, and other
miscellaneous components.
In order for maintenance of the StormFilter
to be successful, it is imperative that all
other components be properly maintained.
The maintenance/repair of upstream
facilities should be carried out prior to
StormFilter maintenance activities.
In addition to considering upstream
facilities, it is also. important to correct any
problems identified in the drainage area.
Drainage area concerns may include:
erosion problems, heavy oil and grease
loading, and discharges of inappropriate
materials.
Material Disposal
The accumulated sediment found in
stormwater treatment and conveyance
systems must be handled and disposed of
in a manner that will not allow the material
to affect surface or ground water. It is
possible for sediments to contain
measurable concentrations of heavy metals
and organic chemicals (such as pesticides
and petroleum products). Areas with the
greatest potential for high pollutant loading
include industrial areas and heavily traveled
roads.
Sediments and water must be disposed of
in accordance with all applicable waste
disposal regulations. It is not appropriate to
discharge untreated materials back to the
stormwater drainage system.
Part of arranging for maintenance to occur
should include coordination of disposal of
solids (landfill coordination) and liquids
(municipal vacuum truck decant facility,
local wastewater treatment plant, on-site
treatment and discharge).
Owners should contact the local public
works department and inquire about how
the department disposes of their street
waste residuals. CONTECH Stormwater
Solutions will determine disposal methods
or reuse of the media contained in the
cartridges. If the material has been
contaminated with any unusual substance,
the cost of special handling and disposal
will be the responsibility of the owner.
©2006 CON TECH Stormwater Solutions Toll-;Fee: 800.548.4667 7 of 9
contechstormwater.com Vault, CI° and Linear StormFilter Operation and Maintenance Guidelines
Date: Personnel:
Location:
System Type: Vault Cast-In-Place Linear
System Observations
Media Months in Service:
Oil and Grease in Forebay: Yes No
Sediment Depth in Forebay:
Sediment Depth on Vault Floor:
Structural Damage:
Estimated Flow from Drainage Pipes (if available):
Cartridges Submerged: Yes No How Deep:
StormFilter Minor Maintenance Activities (check off if done and dive description':)
Trash and Debris Removal:
Minor Structural Repairs:
Drainage Area Report
Excessive Oil and Grease Loading: Yes No Source:
Sediment Accumulation on Pavement: Yes No Source:
Erosion of Landscaped Areas: Yes No Source:
Items Needing Further Work:
Other Comments:
System Size:
Review the condition reports from the previous minor and major maintenance visits.
©2006 CONTECH Stormwater Solutions Toll-free: 800.548.4667 8 of 9
contechstormwater.com Vault, CIP and Linear StornnFilter Operation and Maintenance Guidelines
MT-TO M 1117M M?
Date:
Location:
System Type: Vault Cast-In-Place Linear
List Safety Procedures and Equipment Used:
System Size:
System Observations
Media Months in Service:
Oil and Grease in Forebay: Yes No
Sediment Depth in Forebay:
Sediment Depth on Vault Floor:
Structural Damage:
Drainage Area Report
Excessive Oil and Grease Loading: Yes No Source:
Sediment Accumulation on Pavement: Yes No Source:
Erosion of Landscaped Areas: Yes No Source:
StormFilter Cartridge Replacement Maintenance Activities
Remove Trash and Debris: Yes No Details:
Replace Cartridges: Yes No Details:
Sediment Removed: Yes No Details:
Quantity of Sediment Removed (estimate?):
Minor Structural Repairs: Yes No Details:
Residuals (debris, sediment) Disposal Methods:
Notes:
Personnel:
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contechstormwaieccom Vault, CIP and Linear StormFilter Operation and Maintenance Guidelines