20061376 Ver 1_Report_20060926 (3)

NOVARTIS VACCINES & DIAGNOSTICS
USFCC
HOLLY SPRINGS, NC
BEST MANAGEMENT POND
WET DETENTION POND
DESIGN CALCULATIONS
Jacobs Job No. 22COl 103
SEPTEMBER 22, 2006 RJACOBS
Li -ALCULATION COVER SHEET
PROJECT USFCC JOB NO 22CO1103 DEPARTMENT Civil
CLIENT Novarits Vaccines & Diagnostics CALC. NO. Multiple
SUBJECT BMP Wet Detention Pond - Outlet, Emergency Spillway, Sed Basin, Discharge Apron
ORIGINATOR Ed Kubrin DATE 9/06
CHECKER Various DATE 9/06
PURPOSE OF ISSUANCE
REV
NO. PAGES DESCRIPTION ORIG. DATE CHKD. DATE APRV. DATE
A Issued for Permitting and
Information

COMMENTS: These calculations are in support of an application for a 401 Certification to the North Carolina
Division of Water Quality. The calculations are as follows:
Calc #2, BMP Wet Detention Pond
Calc #1, Wet Detention Pond:
Note Section D, Calc #1, Pond Outlet Structure and Emergeny Spillway
Calc #4, Sediment Basin
Calc #7, Outlet Protection
Note that Calc #1 was prepared using Bentley Pondpack software.
Reference Dwgs: Jacobs Dwg Nos. 00-C-30-99-11, 12, 20,21,22
Calc Cover-BMP Wet Detention Multiple.DOC 02/19/96
CALCULATION COVER SHEET
-'JE PROJECT USFCC JOB NO. 22C01103 DEPARTMENT Civil
CLIENT Novartis Vaccines & Diagnostics CALC. NO. C-2
SUBJECT BMP Wet Detention Pond
ORIGINATOR Ed Kubrin DATE 9/20/06
CHECKER Vance Holt/Tim Horstman DATE 9/20/06
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PURPOSE OF ISSUANCE
REV
NO. PAGES DESCRIPTION ORIG. DATE CHKD. DATE APRV. DATE
A 13 Issued for Permitting and
Information

COMMENTS: These calculations are in support of an application for a 401 Certification to the North Carolina
Division of Water Quality.
Reference Dwgs: Jacobs Dwg Nos. 00-C-30-99-20, 21, 22
Calc Cover-BMP Wet Detention.DOC 02/19/96
Water (duality Narrative
Project: Novartis USFCC
Location: Town of Holly Springs, N. C.
Date: September 22, 2006
Introduction
The purpose of this project is to construct a Pharmaceutical manufacturing facility on a
site located in Holly Springs NC.The facility will produce a flu vaccine. The project will
impact an existing wetlands and perennial streams. The impacts will be less than 1 acre of
wetland and 300 LF of stream. 17 acres of impervious area will be created. A 401permit
has been applied for. As a condition of approval fi-om DWQ a Best Management Practice
(BMP) wet detention pond is proposed to remove 85% of the TSS and to provide
nitrogen reduction. This narrative and calculations support the design of the BMP pond
and the associated erosion control measures
Site Description
At present the site is a wooded area in a rolling terrain. Two perennial streams exist on
the site, one in the North and one in the South. The south stream drains into Thomas Mill
pond and the North proceeds off site eventually draining into Harris Reservoir. Drainage
patterns at the site go to both of these streams.
Erosion Control Measures
The facility being constructed will consist of the following buildings on an 82 tract of
land:
• Bulk Manufacturing Building
• Fill Finish/ Packaging Building
• Warehouse Building
• Facility Operations Building
• Administration/Quality Operations Building
• Yard area for utilities, recycling and trash
• Roads, parking, dock aprons and guard house
• Connector Spine
These buildings create 17 acres of impervious area. Approximately 48 acres of area will
be disturbed and graded. 31 acres will be grass open space. 34 acres, both to the North
and South, will remain wooded and be protected undisturbed open space. Erosion control
measures will be used to keep sediment out of the existing perennial stream. Silt fences,
sediment traps, construction entrances, tree protection fences, and later a sediment basin
will be used. New flow patterns will direct flow into the sediment basin. At completion of
rough grading construction, areas will be seeded, all roads will be gravel covered, and
storm inlet protection will be installed. New flow patterns and storm sewers will direct
flow to the sediment basin. At completion of construction sediment will be removed and
properly disposed of at the sediment basin. The sediment basin will then become the wet
detention pond with water quality control. This pond will also be used to control peak
discharges to predeveloped conditions.
v/' , ,
Design Requirements
Tlie following design requircmcnts (taken from N('DFNR Manual of Stormwater Best
Management Practices, dated April 1999) were used to size the proposed BMP pond:
• Pernianent pool using Table 1.1 using a pond depth of 6 ft. and an impervious of
65% for a full site build out.
• Forebay sized to 20% of the permanent pool volume.
• Temporary pool sized for the 1 inch of rainfall (65% impervious area).
• A 4 inch orifice on a floating skimmer was selected to detain temporary volume
for 4 to 5 days.
• A gabion rock berm will separate the forebay area.
• The pond will also be used to store peak attenuation storage for the 2 yr and the
10 yr storm event.
Plantinp,s at the Pond
At the completion of the grading phase of the stormwater pond construction, erosion
control matting and seeding of a herbaceous ground cover inside the pond should be
conducted to prevent erosion. Once the seeding has taken hold, tree and shrub species
should be installed. The shrubs should be planted on 8-foot centers and the trees should
be planted on 12-foot centers, resulting in a plant density of approximately 1,000 stems
per acre. These plantings are to be installed from the edge of the littoral zone uphill to
the top of the pond structure. A minimum of three species of trees and three species of
shrubs should be utilized to insure minimally adequate plant diversity; however, five
species from both the trees and shrubs categories is highly recommended.
Approximately three shrubs should be planted for every tree, so there should be a shrub
to tree ratio of 3:1. Proportions of specific species to be planted will be based on
availability at time of installation. The size of the plants during installation is important,
tree and shrub species purchased in three-gallon pots is preferable (especially for the tree
species); however, a minimum of one-gallon containers should be used when acquiring
all plants from a nursery. The relatively mature size requirements will help ensure
survivability, as well as, give some assurance that the plants are of size enough to readily
contribute to the bioretention process. The plant material layout should resemble a
random and natural placement of plants rather than a standard landscaped approach with
trees and shrubs in rows. More specific information concerning preparation, installation,
fertilization, and stabilization will be included in contractor specifications. Below is a list
of recommended trees and shrubs appropriate for use for this stormwater pond.
Trees
red maple (Ater rubrum)
eastern red cedar (Juniperus virginiana)
sweet gum (Liquidambar stvraciflua)
sycamore (Platanus occidentalis)
willow oak (Quercus phellos)
black gum (Nvssa svlvatica)
Shrubs
inkberry (Ilex glabra)
spicebush (Lindera banzoin)
arrow-wood (Viburnum dentatum)
sweet pepperbush (Clethra alnifolia)
wax-myrtle (Myrica cerifera)
silky dogwood (Cornus amomum)
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General
a. Basin shape should minimize dead storage areas and short circuiting. Length to width
ratios should be 3:1 or greater. (Barfield, et al., 1981, pp. 426-429; Florida DEP, 1982,
pg. 6-289).
b. If the basin is used as a sediment trap during construction, all sediment deposited during
construction must be removed before normal operation begins.
c. Aquatic vegetation should be included for a wetland type detention basin (Maryland
DNR, March 1987; Schueler, 1987, Chapter 4 and 9). A minimum ten foot wide shallow
sloped shelf is needed at the edge of the basin for safety and to provide appropriate
conditions for aquatic vegetation (Schueler, 1987). This shelf should be sloped 6:1 or
flatter and extend to a depth of 2 feet below the surface of the permanent pool (Shaver
and Maxted, DNREC, 1994). A list of suitable wetland species and propagation
techniques are provided in Schueler (1987) and Maryland DNR (1987).
d. An emergency drain (with a pipe sized to drain the pond in less than 24 hours) should be
installed in all ponds to allow access for riser repairs and sediment removal (Schueler,
1987).
Table 1.1 Surface Area to Drainage Area Ratio For Permanent Pool Sizing For 85% Pollutant
Removal Efficiency in the Piedmont
% Impervious Permanent Pool Denth (feet)
Cover 3.0 4.0 5.0 6.0 7.0 8.0 9.0
in 0-59 0-49 0-43 0-35 0.31 0.29 0-26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
Notes: Numbers given in the body of the table are given in percentages.
Coastal SA/DA ratios can be obtained from the local DWQ Regional Office.
PN 22CO11 Noval 111
--06
Holly Springs, N. C.
Wet Detention Pond Calculations
Total Impoundment Volume

Elevation (FTC- jArea SF j - - Depth (FT) Avg Area (SF) Volume (CF)
- - 308- - --4082 -- - -- ! --- - __ -- --- ...
- 3 ? 6582, 6582
311 9081'1 - -
- ---- -
31 --- -14035, 14035
314, 189881

3?
217631 1 20376 20376
-
- -- ---- ---- - -1.75' -----
24245
-42428
316.75 26726,
0.65 33373 21692
317.4; 40020. '
-

--
----
1 61 - -
- -
-
- 42942',
68706
319;
- 320
-- 322
45863
?-
1 ? 472961 47296
48729 - -
{---- -- - - - 51691 103382
- - -- -- -
54653?- -- ?-_- _
! L
-- - - r -- - - -- - -
Totals i 3244961
PN 22CO1- NovaFM RUll
-J06
Holly Springs, N. C.
Wet Detention Pond Calculations
Perm and Temp Pool Volumes

Elevation (FT) Area SF Depth (FT)
- - - -- 1 1 rt_---
314
-- -- - ' - 1898-_
- - - Avg Area (SF)
+ Volume (CF)

--? --- --- - i
- - ._1 20376
20376
315 21763
i
751
1 24245, 42428
-
31
_?

6726
267261
- L _ ----
-
? i
-
- -- -

i
- L
Totals 44620, 62803

Notes: ------- -
1. Volume available of 62,803 CF is greater than volume required of 60,392 CF.
n
- -
2. Elevation 314 FT is the water quality permanent pool elevatio
.
3. Elevation 316.75 FT is the temporary water quality pool elevation for a 1" storm.
4. Elevation 308 FT is the bottom of the permanent pool.
5. Surface area available at elev 314 FT is 18,988 SF which is greater than the surface required of 18,831 SF.
Faircloth Skimmer -13ct1?1 di lot- Sedorient ;t?;Ii?:
Page 1 of 2
Price list
Effective April 17, 2006
Please note price change effective April 17, 2006. This is the first Increase In skimmer co;
years. The current price of materials has risen significantly in the past 8 months, and we hav,
cottage industry to a business with increased overhead. We appreciate your ongoing t:
Size Price • Shipping Shipping Description
Surcharge Est of Surcharge west
Mississippi River of Mississippi
River
$490.00 Included in price. $13 Drains approximately 3,283
Skimmer cu. ft In 24 hrs., 6,588 cu. ft
basin approximately 48'x 4
or 22,982 cu. ft in
7 days.
2-112" $595.00 Included in price. $14 Drains approximately 6,500
Skimmer cu. ft In 24 hrs., 11,000 cu.
48 hrs. (a basin approximat
66' x 68' x 4' deep), or 38,61
cu. ft In 7 days.
3" $720.00 Included in price. $17 Drains approximately 8,500
Skimmer cu. It In 24 hrs., 17,000 cu.'
48 hrs. (a basin approximat
4' deep) or 69,500 cubic
feet in 7 days.
4" $996.00 Included in price. $23 Drains approximately 18,26
Skimmer cu. ft. In 24 hrs., 36,534 cu.
In 2 days, (a basin
approximately 95' x 95'x 5'
deep), or 127,869 cu. ft In'
days.
5" $1,480.00 Extra charge - Extra charge - Drains approximately 32,83
Skimmer example: about example: about cu. ft In 24 hrs., 65,664 cu.,
$110 shipping $130 shipping 2 days, or 229,824 cu. ft in
charge to PA charge to CA, days.
6" $2,200.00 Extra charge - Extra charge - Drains approximately 61,84
Skimmer example: about example: about cu, ft In 24 hrs., 103,680 cu
$130 shipping $265 shipping in 2 days, or 362,880 cu. ft
charge to PA charge to CA 7 days.
' 5% Discount if paid within 30 days. See. Manual.for. detailed specifications
Does not include pipe for the barrel,
available locally at plumping dealers.
Prices and specifications subject to change without notice.
IMPORTANT NOTES
Prices include shipping EXCEPT for the 5" and 6" skimmers, which must be shipped by truck.
The skimmer size (for example 4" skimmer") is the maximum size of the orifice for that model.
can be made smaller using the supplied plug and cutter to adjust the flow rate to drain the vob
particular basin in the required time.
Flow rates are the maximum with the orifice wide open.
Flow rates given assume no additional flow into the basin after the storm (such as base flow)
restrictions at the outlet (for example, submerged outlet).
Approximate sediment basin size given as examples assumes 2:1 interior side slopes.
The skimmer includes the float, inlet with vent, rope, orifice plug and cutter, and flexible joint.
DOES NOT INCLUDE pipe for the barrel or arm between the inlet and flexible joint, which is
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http://www.fairclothskimrner.coin/slzesprices.htini 6/22/2006
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H@m
Determining Orifice Size
for the
Faircloth Skimmer
March 2005
Important note: The orifice sizing chart in the Pennsylvania
Erosion Control Manual DOES NOT APPLY to Faircloth Skimmers.
It will give the wrong size skimmer. Please use the information
below to choose the size skimmer required for the basin volume
and the orifice size.
Determining the orifice required to drain the sediment basin in the required time involves:
#1, determining the size skimmer required based on the volume of the sediment basin tQ
be drained and the maximum capacity of the particular skimmer with the orifice wide
open; and #2, then determining the radius of the orifice by dividing the volume of the
basin to the drained by a factor for the number of days to drain the basin, which gives
the required area of the orifice, then calculating the orifice radius using Area = it r2 and
solving for r. The cutter can be adjusted to that radius and the orifice cut in the
plastic plug that fits into the inlet.
1. Approximate skimmer maximum capacities based on the typical draw down
requirements, which can vary between States and jurisdictions and watersheds.
If one skimmer does not provide enough capacity, multiple skimmers can be
used to drain the basin. Multiply the 24-hour figure by the number of days
needed.
2" skimmer. 3,283 cubic feet in 24 hours
with a 2" head 6,566 cubic feet in 2 days
22,982 cubic feet in 7 days
2 %" skimmer: 5,500 cubic feet in 24 hours
with a 2" head 11,000 cubic feet in 2 days
38,500 cubic feet in 7 days
3" skimmer: 9,774 cubic feet in 24 hours
with a 3" head 19,547 cubic feet in 2 days
68,415 cubic feet in 7 days
4" skimmer: 18,267 cubic feet in 24 hours
with a 3.3" head 36,534 cubic feet in 2 days
127,869 cubic feet in 7 days
5" skimmer: 32,832 cubic feet in 24 hours
with a 4" head 65,664 cubic feet in 2 days
229,824 cubic feet in 7 days
5 ?'
6" skimmer: 51,840 cubic feet in 24 hours
with a 5" head 103,680 cubic feet in 2 days
362,880 cubic feet in 7 days
2. Factors (in cubic feet of flow per square inch of opening through a round orifice
for the draw down times shown) to use in determining the orifice radius for a
particular basin volume to be drained. This quick method works because the
orifice is centered and has a constant head.
An alternative method is to use the orifice equation with the head for a particular
skimmer shown on the previous page and determine the required orifice to give
the required flow for the volume and draw down time.
2" skimmer: 1,123 to drain the basin in 24 hours
2,246 to drain the basin in 2 days
7,861 to drain the basin in 7 days
2 %2" skimmer: 1,144 to drain the basin in 24 hours
2,304 to drain the basin in 2 days
8,064 to drain the basin in 7 days
3" skimmer: 1,382 to drain the basin in 24 hours
2,765 to drain the basin in 2 days
9,677 to drain the basin in 7 days
4" skimmer: 1,454 to drain the basin in 24 hours
2,909 to drain the basin in 2 days
10,178 to drain the basin in 7 days
5" skimmer: 1,642 to drain the basin in 24 hours
3,283 to drain the basin in 2 days
11,491 to drain the basin in 7 days
6" skimmer: 1,814 to drain the basin in 24 hours
3,628 to drain the basin in 2 days
12,701 to drain the basin in 7 days
The size skimmer necessary for the sediment basin and the required orifice
radius for the skimmer should be shown on the sediment and erosion control
plan for each basin. During the skimmer installation the required orifice can be
cut in the plastic plug using the supplied cutter and installed in the skimmer using
the instructions with the skimmer.
The plan review and enforcement authority may require the calculations showing
that the skimmer used can drain the basin in the required time.
J. W. Faircloth & Son, Inc.
Post Office Box 757
412-A Buttonwood Drive
Hillsborough, North Carolina 27278
Telephone [phone]
FAX [phone]
Revised 2.-2-01; 3-3-05
WET [WETLAND] DETENTION 6ASIN OPERATION AND MAINILNANGE AGREEMENI
[Wetland maintenance wording is bracketed. Please modify the document as appropriate.]
-'he wet [wetland] detention basin system is defined as the wet [wetland] detention basin, pretreatment
Including forebays and the vegetated filter if one is provided.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wet [wetland] detention basin system for sediment accumulation, erosion, trash
accumulation, vegetated cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within
2 to 5 days as designed.
2. Repair eroded areas immediately, re-seed as necessary to maintain good vegetative cover, mow
vegetative cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to
maintain proper functioning.
4. Remove accumulated sediment from the wet [wetland] detention basin system semi-annually or when
depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be
disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact
water quality (i.e. stockpiling near a wet [wetland] detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading and not readily penetrate into accumulated sediments.
When the permanent pool depth reads "IT-C-1 feet in the main pond, the sediment shall be removed.
[For stormwater wetlands: If the elevation of the marsh areas exceed the permanent pool elevation, the
sediment should be removed to design levels. This shall be performed by removing the upper 6 inches of
soil and stockpiling it. Then the marsh area shall be excavated six inches below design elevations.
Afterwards the stockpiled soil should be spread over the marsh surface. The soil should not be stockpiled
for more than two weeks.]
When the permanent pool depth reads 4-G feet in the forebay [and micro-pool], the sediment shall
be removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation %21 C
Sediment moval EI. ?C_14117 \75%
S
----------------- a Sediment Removal Elevation 75%
Bottom E vation' 5 /o
Rn4fnm FIav?4inn s??G,•?;. ? 75 /
FOREBAY MAIN POND
Page 1 of 2
5. kemove cattails ano otP c r it diuE uus wetlano plant: v i c,n they cover 5U% of the basin surface. These
plants shall be encouMoe-CI It ('tc.vV along the vegetate-( shelf and forebay berm.
[For wetlands: Wetland planting densities in the marsh areas should be maintained by replanting bare
areas as needed. Wetland plants should be encouraged to grow in the marsh areas.]
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet [wetland] detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any
changes to the system or responsible party.
Print name:
Title:
Address: x'115 ?-IL t, i?Mn"VU)L'y ?yVog
Phor
Sign,
-Pate
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, Judie M. Ware a Notary Public for the State of raliferr?ia
County of Alameda do hereby certify that StenhPn Tnhncnn
personally appeared before me this 20th day of September 120 6 , and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
I JUDIE M WARE06556
V COMM. 15
SEAL O NOTARY PUBLIC CALIFORNIA Q
ply commission expires coM MErXP DAAt1, UNTY
9,2008
Page 2 of 2
Project No. WW__ (to hcp1.o1)i(lrdhr DUO)
DIVISION 01, WATER QI,AI.1"1')' - 401 WET DETENTION BASIN WORKSHEET
DWQ Stormwater Manag,ement PI n_ c\,ic\\-
A complete storniwater management plan submittal includes a wet detention basin worksheet for each basin,
design calculations, plans and specifications showing all basin and outlet structure details, and a fully executed
operation and maintenance agreement. An incomplete submittal package will result in a request for additional
information and will substantially delay final review and approval of the project.
1. PROJECT INFORMATION (pleasc complete the following information):
... j-2 r-C e
Project Name : N QyAr1Z 70,; r-
Contact Person: $V kyP??,l?! /?hnl? GL'"- Phone Number: (?ti??) $5?? XD??
For projects with multiple basins, specifv which basin this worksheet applies to: Orl', 80',el ?l
Basin Bottom Elevation ft. (average elevation of the floor of the basin)
Permanent Pool Elevation ?7 14-, c _ ft. (elevation of the orifice invert out)
Temporary Pool Elevation 1G.? ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area I gR g? sq. ft. (water surface area at permanent pool elevation)
Drainage Area ac. (on-site and off-site drainage to the basin)
Impervious Area I ? • ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 11,041,5; cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume /,2$00i cu. ft. (volume detained on top of the penmanent pool)
Forebay Volume Zo9*-?+_ cu. ft.
SA/DA used l • G5 (surface area to drainage area ratio)
Diameter of Orifice q-' in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Applicants Initials
The temporary pool controls runoff from the 1 inch storm event.
K The basin length to width ratio is greater than 3:1.
?1 K The basin side slopes are no steeper than 3:1.
?? le. A submerged and vegetated perimeter shelf at less than 6:1 is provided.
WK Vegetation to the permanent pool elevation is specified.
0i 1 __ An emergency drain is provided to drain the basin.
lu V. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
ilk- The temporary pool draws down in 2 to 5 days.
WIL The forebay volume is approximately equal to 20% of the total basin volume.
fA-Sediment storage is provided in the penmanent pool.
Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
???H A site specific operation and maintenance (O&M) plan is provided.
{ A vegetation management/mowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
?(?? A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
?I?' A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of]
CALCULAT ION COVER SHEET
PROJECT USFCC JOB NO. 22C01103 DEPARTMENT Civil
CLIENT Novarits Vaccines & Diagnostics CALC. NO. C-1
SUBJECT BMP Wet Detention Pond - Stormwater Quantities, Outlet, and Emergency Spillway
ORIGINATOR Ed Kubrin DATE 9/06
CHECKER Mark Smith DATE 9/06
U
9,,4
PURPOSE OF ISSUANCE
REV
NO. PAGES DESCRIPTION ORIG. DATE CHKD. DATE APRV. DATE
A 125 Issued for Permitting and
Information

COMMENTS: These calculations are in support of an application for a 401 Certification to the North Carolina
Division of Water Quality.
Note that these calculations were prepared using Bentley Pondpack software.
Reference Dwgs: Jacobs Dwg Nos. 00-C-30-99-11, 12, 20, 21, 22
Calc Cover-BMP Pondpack Calc-OUtlet.DOC; Emergency Spill.DOC 02/19/96
Calculation #1
Wet Detention Pond
Stormwater Ouantity Control
Table of Contents
Section Description
A Input Summary
B Drainage Area 1
C Drainage Area 2,3
D Pond Outlet Structure/
Emergency Spillway
Appendix A Pre & Post Conditions Maps
Wet Detention Pond Plan
Appendix B Soils Map
Vegetative Analysis Map
Project: Novartis USFCC
Location: TBD
Date: 7/16/2006
Subject: Site Land Use
Predeveloped Land Use Type B Soil
Land Use Designation
Drainage Area Total Area A B C
D E
DA1 18.6 18.6
DA2 23.3 23.3
DA3 29.5 29.5
Acres 71.4 0 0 71.4 0 0 0
Post Developed Land Use
Drainage Area Total Area
Type B Soil
Land Use Designation
A B C
DA-1a 8.8 0.5 2 6.3
DA-2a 15 8.8 6.2
DA-3a 23 10 3 10
DA-(1,2,3)b 26.2 8.7 17.5
Acres 73 28 22.5 22.5
Land Use Legend
A Grass "Good"
B Pavement/Buildings
C Woods "Good"
71.4
73
Novartis
22COI 16S
July 2006
Pre Developed Drainage Areas
2 yr P= 3.6
Drainage Area Designation: DA-1
Total Length: 1770
Drainage Area: 17 Acres
Flow Type
Sheet flow
Shallow flow
Channel flow
Channel flow
Travel
Distance Slope Wetted Perimeter Flow Area
Mnnninn'c "n" Ift.) (ft/ftl (feet) Iso. ft.1
0.4 200 0.07
240 0.12
0.06 630 0.05 80 180
0.06 1140 0.014 80 180
2210
Drainage Area Designation: DA-2
Total Length: 1730
Drainage Area: 23.3 Acres
Flow Type
Sheet flow
Shallow flow
Shallow flow
Channel flow
Travel
Distance Slope Wetted Perimeter Flow Area
Mnnninn'c "n" Ift 1 /ft/ftl (fPP?l Inn_ ft_I
0.4 200 0.08
330 0.055
350 0.011
0.06 850 0.052 80 180
1730
Drainage Area Designation: DA-3
Total Length: 1690
Drainage Area: 29.5 Acres
Flow Type
Sheet flow
Shallow flow
Channel flow
Channel flow
Channel flow
Travel
Distance Slope Wetted Perimeter Flow Area
Manninn's "n" Ift_1 Ift/ftl (feet) (an. ft.)
0.4 200 0.05
125 0.16
0.06 660 0.05 80 180
0.06 410 0.02 80 180
0.06 295 0.047 80 180
1690
Novartis
22COl 16S
July 2006
Post Developed Drainage Areas
2 yr P= 3.6
Drainage Area Designation: DA-1a
Total Length: 1480 LF
Drainage Area: 9.2 Acres
Flow Type
Sheet flow
Channel flow (existing)
Channel flow (existing)
Travel
Distance Slope Wetted Perimeter Flow Area
Manninn's "n" Ift.l Ift/M Ifpptl Isn_ ft l
0.24 200 0.10
0.06 230 0.053 80 180
0.06 1270 0.013 80 180
1700
Drainage Area Designation: DA-2a
Total Length: 1150'
Drainage Area: 9.3 Acres
Flow Type
Sheet flow
Shallow flow
Channel flow (existing)
Travel
Distance Slope Wetted Perimeter Flow Area
Manninn's "n" Ifil MIM /fpptl fcn_ ftI
0.24 200 0.01
675 0.01
0.06 700 0.052 80 180
1575
Drainage Area Designation: DA-3a
Total Length: 1790
Drainage Area: 23 Acres
Flow Type
Sheet flow
Shallow flow
Channel flow (new)
Culvert
Channel flow (new)
Existing channel
Travel
Distance Slope Wetted Perimeter Flow Area
Manninn's "n" Ift.1 Ift/ftl /fpptl /sn_ ft _1
0.4 200 0.05
125 0.16
0.06 660 0.05 80 180
0.009 100 0.0075 9.5 7
0.06 410 0.02 80 180
0.06 295 0.047 80 180
1790
Drainage Area Designation: DA-(1,2,3)b
Total Length: 1130
Drainage Area: 28.3 Acres
Flow Type
Sheet flow
Shallow flow
HDPE Culvert
Travel
Distance Slope Wetted Perimeter Flow Area
Manninn's "n" Ift_1 /ft/ftl Ifpptl /en ft 1
0.24 200 0.0075
50 0.0075
0.009 1720 0.008 9.5 7
1970
Project: Novartis USFCC
Location: TBD
Date: 7/16/2006
Subject: Reach Route DA3 to Outlet
Calculate "time translation" to convey water down Perennial Stream to common Outlet
Flow Area Wet Perimeter Hydraulic Radius R Slope S Mannings N
104 64 1.625 0.01 0.06
Velocity V fps Time hr
3.44 0.10
Length ft
1260
V=1.49'(R^0.67)'(S^0.5)/N
T=L/(V'3600)
Job Fi ] e : I : AC1VI LAPONDF1(F , ; '- ; 1 1 ',;E] 0[1'1'\ FREDA] . FFP
Rain Dir: I: AC IV IL\PONCI;.i:F'„ i_i I i_.??'CLGP}
JOB TITLE
Project Date: 9/19/2006
Project Engineer: Ed Kubrin
Project Title: Novartis Holly Springs
Project Comments:
Predeveloped Conditions and Discharge from 2, 10 & 100 yr storm
events in Drainage Area #1
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 7:54 AM 9/21/2006

Out DA 1

DA 1
D/', Pre100
50
40

.` 30

v
3
0
ix
20

i
10

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Time (hrs)
DA1 Pre 2
DA1 Pre 10
:%;4.:_z?7r„1113 DA1 Pre100
Job File: I: ACIVIL\PONDFACK\PREDTF"J! : ? . i ! ` I i-P1'=.. 1 11
Rain Dir: I:\CIVIL\PONDPACK\PREDEVELOFLD\
JOB TITLE
Project Date: 9/19/2006
Project Engineer: Ed Kubrin
Project Title: Novartis Holly Springs
Project Comments:
Predeveloped Conditions and Discharge from 2, 10 & 100 yr storm
events in Drainage Area #1
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 7:29 AM 9/21/2006
Jot: F' le: I : \CIVI1 \FOF:I ! LCI r: I'kr.f,A] .1'r':
Rain Dir: 1: ACIVIL\PON1!i H_? l I i-,! iqi VLLOI'ED\

******************* *+ MASTER SUMMARY ****+**+**+**++***+*+*
Watershed....... Master. Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
Holly Springs NC Design Storms ...................... 2.01
***+**a+****+++*++*+** TC CALCULATIONS +**++**++++**+*+++*+*
DA1 ............. Tc Calcs ........................... 3.01
+*+*+*+++****+++++***+ CN CALCULATIONS ***+++**+*+*+******++
DA1 ............. Runoff CN-Area ..................... 4.01
*****++*++**+++***+* RUNOFF HYDROGRAPHS ****+**+*********+**
Unit Hyd. Equations ................ 5.01
DA1 ............. Pre 2
Unit Hyd. Summary .................. 5.03
DA1 ............. Pre 10
Unit Hyd. Summary .................. 5.04
DA1 ............. Pre100
Unit Hyd. Summary .................. 5.05
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Table of Contents
I
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Holly Springs NC
Total
Depth Rainfall
Return Event in Type RNF ID
------------
Pre 2 ------
3.6000 ----------------
Synthetic Curve ----------------
TypeII 24hr
Pre 10 5.2800 Synthetic Curve TypeII 24hr
Pre100 8.0000 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

4 Return HYG Vol
ode ID
------------- Type
---- ---- Event
------ ac-ft Trun
---------- --
DA1 AREA 2 .589
DA1 AREA 10 1.740
DA1 AREA 100 4.315
*OUT DA1 JCT 2 .589
*OUT DA1 JCT 10 1.740
*OUT DA1 JCT 100 4.315
Qpeak
hrs
12.2700
12.2100
12.1600
12.2700
12.2100
12.1600
Max
Qpeak Max WSEL Pond Storage
cfs ft ac-ft
-------- -------- ------------
3.38
15.49
44.44
3.38
15.49
44.44
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Master Networ}? Fca E i.01
Name.... Watershed
File.... I:\CIVIL\POND PF.CK\IREDEVELOPED\PREDAl.ppw

Title... Project Date: 7/19/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Predeveloped Conditions and Discharge from 2, 10 &
100 yr storm events in Drainage Area #1
DESIGN STORMS SUMMARY
Design Storm File,ID = Holly Springs NC
Storm Tag Name = Pre 2
Data Type, File, ID =
Storm Frequency =
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Synthetic Storm TypeII 24hr
2 yr
3.6000 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Pre 10
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.2800 in
Duration Multiplier = I
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Pre100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Design Storms
Name.... Holly Springs NC
File.... I:\CIVIL\PONDPACK\PREDEVELOPEC\PREDAI.ppw

........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .4000
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .070000 ft/ft
Avg.Velocity .16 ft/sec
Segment #1 Time: .3559 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 240.00 ft
Slope .120000 ft/ft
Unpaved
Avg.Velocity 5.59 ft/sec
Segment #2 Time: .0119 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 180.0000 sq.ft
Wetted Perimeter 80.00 ft
Hydraulic Radius 2.25 ft
Slope .050000 ft/ft
Mannings n .0600
Hydraulic Length 630.00 ft
Avg.Velocity 9.53 ft/sec
Segment #3 Time: .0184 hrs
------------------------------------------------------------------------
S/N: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
4:17 PM
Bentley Systems, Inc.
9/20/2006
Type.... TC Calcs
Name.... DA1
Fil.e.... I:\CIVIL\PONDPACK\P1.EDEVELOPED\PREDA1.ppw
Segment $4: Tc: TR-55 Channel
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
Avg.Velocity
180.0000 sq. f.t
80.00 ft
2.25 ft
.014000 ft/ft
.0600
1140.00 ft
5.05 ft/sec
F`,:cr .01
Segment 04 Time: .0628 hrs
-------------------------------------------------------------------------
Total Tc: .4490 hrs
-------------------------
S/N: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
4:17 PM
Bentley Systems, Inc.
9/20/2006
Type.... Tc Calcs
Name.... DA1
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDAl.ppw
F'ac?
-----------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
SCS TR-55 Sheet Flow =--------------------------------------- -----
Tc = (.007 * ((n * Lf)**0.8)) / (P** .5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
___= SCS TR-55 Shallow Concentrated Flow
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
4:17 PM
Bentley Systems, Inc.
9/20/2006
T"'j)( .... Tc calcF
Namt.... DAi
File.... I:ACIVIL\PONDFACE\PI?FDEVELOPED\PREDAl.ppw
,'aaF 3.03
___= SCS Channel Flow =__________________________________=====
R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
Hydraulic radius
Flow area, sq.ft.
Wetted perimeter, ft
Velocity, ft/sec
Slope, ft/ft
Manninos n
Time of ccncentration, hrs
Flow length, ft
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Tc Calcs
Name.... DA1
parr . r.;
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Woods - good 55 18.600 55.00
COMPOSITE AREA & WEIGHTED CN ---> 18.600 55.00 (55)
...........................................................................
...........................................................................
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Runoff CN-Arec. "race 4.01
Namur.... DA1
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
DEFINITION OF TERMS: ------------------------------------------------
At = Total area (acres): At = Ai+Ap
Ai = Impervious area (acres)
Ap = Pervious area (acres)
CNi = Runoff curve number for impervious area
CNp = Runoff curve number for pervious area
fLoss = f loss constant infiltration (depth/time)
gKs = Saturated Hydraulic Conductivity (depth/time)
Md = Volumetric Moisture Deficit
Psi = Capillary Suction (length)
hK = Horton Infiltration Decay Rate (time-1)
fo = Initial Infiltration Rate (depth/time)
fc = Ultimate(capacity)Infiltration Rate (depth/time)
Ia = Initial Abstraction (length)
dt = Computational increment (duration of unit excess rainfall)
Default dt is smallest value of 0.1333Tc, rtm, and th
(Smallest dt is then adjusted to match up with Tp)
?JDdt = User specified override computational main time increment
(only used if UDdt is => .1333Tc)
D(t) = Point on distribution curve (fraction of P) for time step t
K = 2 / (1 + (Tr/Tp)): default K = 0.75: (for Tr/Tp = 1.67)
Ks = Hydrograph shape factor
Unit Conversions * K:
((1hr/3600sec) * (lft/12in) * ((5280ft)**2/sq.mi)) * K
Default Ks = 645.333 * 0.75 = 484
Lag = Lag time from center of excess runoff (dt) to Tp: Lag = 0.6Tc
P = Total precipitation depth, inches
Pa(t) = Accumulated rainfall at time step t
Pi(t) = Incremental rainfall at time step t
qp = Peak discharge (cfs) for lin. runoff, for lhr, for 1 sq.mi.
_ (Ks * A * Q) / Tp (where Q = lin. runoff, A=sq.mi.)
Qu(t) = Unit hydrograph ordinate (cfs) at time step t
Q(t) = Final hydrograph ordinate (cfs) at time step t
Rai(t)= Accumulated runoff (inches) at time step t for impervious area
Rap(t)= Accumulated runoff (inches) at time step t for pervious area
Rii(t)= Incremental runoff (inches) at time step t for impervious area
Rip(t)= Incremental runoff (inches) at time step t for pervious area
R(t) = Incremental weighted total runoff (inches)
Rtm = Time increment for rainfall table
Si = S for impervious area: Si = (1000/CNi) - 10
Sp = S for pervious area: Sp = (1000/CNp) - 10
t = Time step (row) number
Tc = Time of concentration
Tb = Time (hrs) of entire unit hydrograph: Tb = Tp + Tr
Tp = Time (hrs) to peak of a unit hydrograph: Tp = (dt/2) + Lag
Tr = Time (hrs) of receding limb of unit hydrograph: Tr = ratio of Tp
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Unit Hyd. Equataon?
Name....
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDAI.ppw
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
PRECIPITATION: --- ---- ----------------------------------------
Column (1): Time for time step t
Column (2): D(t) = Point on distribution curve for time step t
Column (3): Pi(t) = Pa(t) - Pa(t:-1): Col-(4) - Preceding Col.(4)
Column (4): Pa(t) = D(t) x P: Col.(2) x P
PERVIOUS AREA RUNOFF (using SCS Runoff CN Method) ------------------------
Column (5): Rap(t) = Accumulated pervious runoff for time step t
If (Pa(t) is <= 0.2Sp) then use: Rap(t) = 0.0
If (Pa(t) is > 0.2Sp) then use:
Rap(t) _ (Col.(4)-0.2Sp)**2 / (Col.(4)+0.8Sp)
Column (6): Rip(t) = Incremental pervious runoff for time step t
Rip(t) = Rap(t) Rap(t-1)
Rip(t) = Col.(5) for current row - Col.(5) for preceding row.
IMPERVIOUS AREA RUNOFF ---------------------------------------------------
Column (7 & 8)... Did not specify to use impervious areas.
INCREMENTAL WEIGHTED RUNOFF: ----------------------------------------------
Column (9): R(t) _ (Ap/At) x Rip(t) + (Ai/At) x Rii(t)
R(t) _ (Ap/At) x Ccl.(6) + (Ai/At) x Col.(8)
SCS UNIT HYDROGRAPH METHOD: -----------------------------------------------
Column (10): Q(t) is computed with the SCS unit hydrograph method
using Ro and Quo.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Unit Hyd. Er,u: ,.. Pace 5.02
Name....
File.... I:ACIVIL\PONDPACK\PREPEVELOPED\PREDA1.ppw
SCS UNIT HYDP.OGRAPH METHOD
STORM EVENT: 2 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 3.6000 in
I:\CIVIL\PONDPACK\PREDEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\PREDEVELOPED\
- DA1 Pre 2
.4490 hrs
18.600 acres Runoff CN= 55
Computational Time Increment = .05987 hrs
Computed Peak Time 12.2724 hrs
Computed Peak Flow = 3.39 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2702 hrs
Peak Flow, Interpolated Output = 3.38 cfs
--------------------------------------------
DRAINAGE AREA
ID:DA1
CN = 55
Area = 18.600 acres
S = 8.1818 in
0.2S = 1.6364 in
Cumulative Runoff
-------------------
.3801 in
.589 ac-ft
HYG Volume... .589 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .44899 hrs (ID: DA1)
Computational Incr, Tm = .05987 hrs = 0.20000 Tp
Unit Hyd. Shape Fact or = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 46.94 cfs
Unit peak time Tp = .29933 hrs
Unit receding limb, Tr = 1.19730 hrs
Total unit time, Tb = 1.49663 hrs
j c / r
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/2.0/2006
Type.... Unit Hyd. Summary
Name.... DAI Tag: Fl(E
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA1.ppw
Storm... TypeII 24hr Tag: Pre 2
P,-? (!, .I'--
Event- : , Yi
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 5.2800 in
I:\CIVIL\PONDPACK\PREDEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\PREDEVELOPED\
- DAI Pre 10
.4490 hrs
18.600 acres Runoff CN= 55
Computational Time Increment = .05987 hrs
Computed Peak Time = 12.2125 hrs
Computed Peak Flow = 15.51 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2102 hrs
Peak Flow, Interpolated Output = 15.49 cfs
DRAINAGE AREA
ID:DAl
CN = 55
Area = 18.600 acres
S = 8.1818 in
0.2S = 1.6364 in
Cumulative Runoff
-------------------
1.1227 in
1.740 ac-ft
HYG Volume... 1.740 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .44899 hrs (ID: DAI)
Computational Incr, Tm = .05987 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 46.94 cfs
Unit peak time Tp = .29933 hrs
Unit receding limb, Tr = 1.19730 hrs
Total unit time, Tb = 1.49663 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley Pond Pack (10.00.023.00) 4:17 PM 9/20/2006
Type.... Unit Hyd. Sum=n... r: e 5.04
Name.... DA1 IC 1u Event: 1.0 yr
File. ... 1:\CIVIL\PONDPAC'K\]1<F,DEVELOPED\PREDAl.ppw
'? 1, ,
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
Rain File -ID - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
HYG File - ID = - DA1 Pre100
Tc = .4490 hrs
Drainage Area = 18.600 acres Runoff CN= 55
--------------------------------------------
Computational Time Increment = .05987 hrs
Computed Peak Time = 12.1526 hrs
Computed Peak Flow = 44.53 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1602 hrs
Peak Flow, Interpolated Output = 44.44 cfs
DRAINAGE AREA
ID:DA1
CN - 55
Area = 18.600 acres
S = 8.1818 in
0.25 = 1.6364 in
Cumulative Runoff
-------------------
2.7841 in
4.315 ac-ft
HYG Volume... 4.315 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .44899 hrs (ID: DA1)
Computational Incr, Tm = .05987 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 46.94 cfs
Unit peak time Tp = .29933 hrs
Unit receding limb, Tr = 1.19730 hrs
Total unit time, Tb = 1.49663 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:17 PM 9/20/2006
Job File: I: ACIVIL\PONDPACK\FCc'.° ? vr? }=F ns i r... PpW
Rain Dir: I:\CIVIL\PONDPACK\F0S7' LLVtLCFLU,
JOB TITLE
--------------------------
Project Date: 9/20/2006
Project Engineer: Ed Kubrin
Project Title: Novartis Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, & 100 yr storm
events in Drainage Area #1. Post developed discharge volume is
less than predeveloped discharge volume.
Post developed DA#1 is reduced in size. Impervious area added to
DA1,2,3b and routed through Pond DA 123.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 7:53 AM 9/21/2006
40
30':

U
3 20i
0

101
I

8 9 10 11
OUTFlA l-
DeV100

OUTDAIA Dev 2
OUTDAIA Dev 10
OUTDAIA Dev100
12 13 14 15 16 17 18 19 20 21 22 23 24 25
Time (hrs)
PondMaker Design Wizard
Pre DevM Pre Dev Post Dev Post Total
Return
:
peak
Volume
Peak
Volume
Event (cfs) (ac-ft) (cfs) (ac-ft)
2 3.3848 0.58907 7.1140 0.59033
10 15.4947 1.74009 17.9517 1.35117
100 44.4352 4.31524 39.1488 2.85569
Estimated Interp. W.S. Freeboard
Storage Elev. Depth
(ac-ft) (ft) (ft)
0.00000 0.0000 FAIL
0.00000 0.0000 FAIL
0.00000 0.0000 FAIL
JoL File: I : ACTVII,A} ONl'T : 17F TT=DI :..: .
Rain Dir: I:ACIV1L\PONL,}h.LGVLi,OFliD\
JOB TITLE
--------------------------
--------------------------
Project Date: 7/20/2006
Project Engineer: Ed Kubri.n
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, & 100 yr storm
events in Drainage Area 01. Post developed discharge volume is
less than predeveloped discharge volume.
Post developed DA#1 is reduced in size. Impervious area added to
DA1,2,3b and routed through Pond DA 123.

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Job File: I:ACIVIL\PONDPPCK,AFC:" .:)',', ? 1' 1' ".":A]A.1-PW
Rain Dir: I:\CIVIL\PONDPACK\POET DEVELOPED\
***********+*+*+++*+++ MASTER SUMMARY *++*+++++*+++*+++*++++
Watershed....... Master Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
Holly Springs NC Design Storms ...................... 2.01
+**********++**+**++++ TC CALCULATIONS *+++++++**+a+++++++++
DATA............ Tc Calcs ........................... 3.01
***++*****+*a+*+**++++ CN CALCULATIONS *****+*++*+**+++*++++
DATA............ Runoff CN-Area ..................... 4.01
******************** RUNOFF HYDROGRAPHS *****************+++
Unit Hyd. Equations ................ 5.01
DATA............ Dev 2
Unit Hyd. Summary .................. 5.03
DATA............ Dev 10
Unit Hyd. Summary .................. 5.04
DATA............ Dev100
Unit Hyd. Summary .................. 5.05
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
J L.
T a h I ( of Contents
MASTER DESIGN STORM SUMMARY
Network Storm Collection: [lolly Springs NC
Total
Depth Rainfall
Return Event in Type RNF ID
-
-
------------
Dev 2 ------
3.6000 ----------------
Synthetic Curve ---------
TypelI --
----
24hr
Dev 10 5.2800 Synthetic Curve TypeIl 24hr
Dev100 8.0000 Synthetic Curve TypeIl 24hr
i
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall.; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol
Node ID Type Event
------ ac-ft Trun
----------
-----------
DATA ------ ----
AREA 2 .590
DATA AREA 10 1.351
DATA AREA 100 2.856
*OUTDAlA JCT 2 .590
*OUTDAlA JCT 10 1.351
*OUTDAlA JCT 100 2.856
PONDDAlA IN POND 2 .590
PONDDAlA IN POND 10 1.351
PONDDAIA IN POND 100 2.856
PONDDAIA OUT POND 2 .590
PONDDAlA OUT POND 10 1.351
PONDDAlA OUT POND 100 2.856
Max
Qpeak Qpeak Max WSEL Pond Storage
hr.s
-------- cfs ft ac-ft
-------- -------- ------------
-
12.0900 7.11
12.0800 17.95
12.0500 39.15
12.0900 7.11
12.0800 17.95
12.0500 39.15
12.0900 7.11
12.0800 17.95
12.0500 39.15
12.0900 7.11
12.0800 17.95
12.0500 39.15
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:19 PM
Bentley Systems, Inc.
9/20/2006
Type.... Master Network Sunminr-.
Name.... Watershed
File.... I:\CIVIL\PONDPACK\POST DEVELOPS M POSTDAla.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, &
100 yr storm events in Drainage Area #l. Post
developed discharge volume is less than predeveloped
discharge volume.
Post developed DA#1 is reduced in size. Impervious
area added to DA1,2,3b and routed through Pond DA 123.
DESIGN STORMS SUMMARY
Design Storm File,ID =
Storm Tag Name = Dev 2
Holly Springs NC
Pa";?
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev 10
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.2800 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Type .... De =j an St oI 111 01
Name.... Holly Springs IQ(
File.... I:\CIVIL\PONDPACK\POS'' DEVELOPED\POSTDA1a.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #l: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .100000 ft/ft
Avg.Velocity .27 ft/sec
Segment #1 Time: .2051 hrs
------------------------------------------------------------------------
Segment #2: Tc:
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
TR-55 Channel
180.0000 sq.ft
80.00 ft
2.25 ft
.052000 ft/ft
.0600
230.00 ft
Avg.Velocity 9.72 ft/sec
Segment #2 Time: .0066 hrs
------------------------------------------------------------------------
Segment #3: Tc:
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
TR-55 Channel
180.0000 sq.ft
80.00 ft
2.25 ft
.013000 ft/ft
.0600
1270.00 ft
Avg.Velocity 9.86 ft/sec
Segment #3 Time: .0726 hrs
------------------------------------------------------------------------
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Type.... Tc Ca lcs
Name.... DA1A
File.... 1:\CIVIL\PONDPACK\POST DEVELOPED\POSTDAla.ppw

-------------------------
-------------------------
Total Tc: .2842 hrs
-------------------------
-------------------------
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Tyhe.... Tc Cake 3.02
Name.... DAM
Fi.le.... I:\CIVIL\PONDFAC}C\PCRT DEVELOPED\POSTDA1a.ppw
-------------------------------------------------------------------------
Tc Equations used...
-------------------------------------------------------------------------
___= SCS TR-55 Sheet Flow ______------ _____---- _____
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft_
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
__= SCS Channel Flow ___________
R = Aq / Wp
V = (1.99 * (R**(2/3)) * (Sf**-0.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
Hydraulic radius
Flow area, sq.ft.
Wetted perimeter, ft
Velocity, ft/sec
Slope, ft/ft
Mannings n
Time of concentration, hrs
Flow length, ft
S/N: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:19 PM
Bentley Systems, Inc.
9/20/2006
Type.... Tc Ca1cs
Name.... DATA

RUNOFF CURVE NUMBER DATA
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
--------------------------------
Open space (Lawns,parks etc.) - Goo ----
61 ---------
.500 ----- ----- ------
61.00
Impervious Areas - Paved parking to 98 2.000 98.00
Woods - good 55 6.300 55.00
COMPOSITE AREA & WEIGHTED CN ---> 8.800 65.11 (65)
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Type.... Runoff CN-Al'( r
Name.... DATA
P'
Fhce 4.01
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
DEFINITION OF TERMS: ------------------------------------------------
At = Total area (acres): At = Ai+Ap
Ai = Impervious area (acres)
Ap = Pervious area (acres)
CNi = Runoff curve number for impervious area
CNp = Runoff curve number for pervious area
fLoss = f loss constant infiltration (depth/time)
gKs = Saturated Hydraulic Conductivity (depth/time)
Md = Volumetric Moisture Deficit
Psi = Capillary Suction (length)
hK = Horton Infiltration Decay Rate (time^-1)
fo = Initial Infiltration Rate (depth/time)
fc = Ultimate(capacity)Infiltration Rate (depth/time)
Ia = Initial Abstraction (length)
dt = Computational increment (duration of unit excess rainfall)
Default dt is smallest value of 0.1333Tc, rtm, and th
(Smallest dt is then adjusted to match up with Tp)
UDdt = User specified override computational main time increment
(only used if UDdt is => .1333Tc)
D(t) = Point on distribution curve (fraction of P) for time step t
K = 2 / (1 + (Tr/Tp)): default K = 0.75: (for. Tr/Tp = 1.67)
Ks = Hydrograph shape factor
= Unit Conversions * K:
_ ((lhr/3600sec) * (lft/12in) * ((5280ft)**2/sq.mi)) * K
Default Ks = 645.333 * 0.75 = 484
Lag = Lag time from center of excess runoff (dt) to Tp: Lag = 0.6Tc
P = Total precipitation depth, inches
Pa(t) = Accumulated rainfall at time step t
Pi(t) = Incremental rainfall at time step t
qp = Peak discharge (cfs) for tin. runoff, for lhr, for 1 sq.mi.
_ (Ks * A * Q) / Tp (where Q = lin. runoff, A=sq.mi.)
Qu(t) = Unit hydrograph ordinate (cfs) at time step t
Q(t) = Final hydrograph ordinate (cfs) at time step t
Rai(t)= Accumulated runoff (inches) at time step t for impervious area
Rap(t)= Accumulated runoff (inches) at time step t for pervious area
Rii(t)= Incremental runoff (inches) at time step t for impervious area
Rip(t)= Incremental runoff (inches) at time step t for pervious area
R(t) = Incremental weighted total runoff (inches)
Rtm = Time increment for rainfall table
Si = S for impervious area: Si = (1000/CNi) - 10
Sp = S for pervious area: Sp = (1000/CNp) - 10
t = Time step (row) number
Tc = Time of concentration
Tb = Time (hrs) of entire unit hydrograph: Tb = Tp + Tr
Tp = Time (hrs) to peak of a unit hydrograph: Tp = (dt/2) + Lag
Tr = Time (hrs) of receding limb of unit hydrograph: Tr = ratio of Tp
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:19 PM
Bentley Systems, Inc.
9/20/2006
Type.... Unit Hyd. Lquat]on< Iz:n
Name....
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDAla.ppw
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
PRECIPITATION: -----------------------------------------------------------
Column (1): Time for time step t
Column (2): D(t) = Point on distribution curve for time step t
Column (3): Pi(t) = Pa(t) - Pa(t-1): Col.(4) - Preceding Col.(4)
Column (9): Pa(t) = D(t) x P: Col.(2) x P
PERVIOUS AREA RUNOFF (using SCS Runoff CN Method) ------------------------
Column (5): Rap(t) = Accumulated pervious runoff for time step t
If (Pa(t) is <= 0.2Sp) then use: Rap(t) = 0.0
If (Pa(t) is > 0.2Sp) then use:
Rap(t) = (Col.(9)-0.2Sp)**2 / (Col.(4)+0.8Sp)
Column (6): Rip(t) = Incremental pervious runoff for time step t
Rip(t) = Rap(t) - Rap(t-1)
Rip(t) = Col.(5) for current row - Col.(5) for preceding row.
IMPERVIOUS AREA RUNOFF ---------------------------------------------------
Column (7 & 8)... Did not specify to use impervious areas.
INCREMENTAL WEIGHTED RUNOFF: ---------------------------------------------
Column (9): R(t) = (Ap/At) x Rip(t) + (Ai/At) x Rii(t)
R(t) = (Ap/At) x Col.(6) + (Ai/At) x Col.(8)
SCS UNIT HYDROGRAPH METHOD: ----------------------------------------------
Column (10): Q(t) is computed with the SCS unit hydrograph method
using Ro and Quo.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Typ( . ... Unit Hyd. Equr aE .02
Name....
File.... I:ACIVIL\POND FACK\PCST DEVELOPED\POST DAla.ppw
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 3.6000 in
1:\CIVIL\PONDPACK\POST DEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\POST DEVELOPED\
- DA1A Dev 2
.2842 hrs
6.800 acres Runoff CN= 65
--------------------------------------------
Computational Time Increment = .03790 hrs
Computed Peak Time - 12.0686 hrs
Computed Peak Flow = 7.12 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.0902 hrs
Peak Flow, Interpolated Output = 7.1.1 cfs
--------------------------------------------
-------------------------------------------
DRAINAGE AREA
ID:DAIA
CN = 65
Area = 8.800 acres
S 5.3846 in
0.2S = 1.0769 in
Cumulative Runoff
------------------
.8050 in
.590 ac-ft
HYG Volume... .590 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .28422 hrs (ID: DA1A)
Computational Incr, Tm = .03790 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Reced ing/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 35.08 cfs
Unit peak time Tp = .18948 hrs
Unit receding limb, Tr = .75792 hrs
Total unit time, Tb = .94740 hrs

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Type.... Unit Hyd. Summary Fc.cF
Name.... DATA Tag: Dev 2 Event: - yr
File.... I:\CIVIL\PONDPACK\POST DFVELOPED\POSTDAla.ppw
Storm... TypeII 24hr 'log: Dev 2
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration = 24.0000 hrs Rain Depth = 5.2800 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Di.r = L•\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = - DATA Dev 10
Tc = .2842 hrs
Drainage Area = 8.800 acres Runoff CN= 65
Computational Time Increment = .03790 hrs
Computed Peak Time = 12.0888 hrs
Computed Peak Flow = 17.99 cfs
Time Increment for HYG File - .0100 hrs
Peak Time, Interpolated Output = 12.0802 hrs
Peak Flow, Interpolated Output = 17.95 cfs
DRAINAGE AREA
ID:DAIA
CN = 65
Area = 8.800 acres
S = 5.3846 in
0.2S = 1.0769 in
Cumulative Runoff
-------------------
1.8426 in
1.351 ac-ft
HYG Volume... 1.351 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .28422 hrs (ID: DATA)
Computational Incr, Tm = .03790 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(l+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 35.08 cfs
Unit peak time Tp = .18948 hrs
Unit receding limb, Tr = .75792 hrs
Total unit time, Tb = .94740 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Type.... Unit Hyd. `unuo.: adF- .01 `
Name.... DATA Dev Ic Event: 10 yr
File.... I:\CIVIL\PONDPACK\1=CST DEVELOPED\POSTDAla.ppv.
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = - DATA Dev100
Tc = .2842 hrs
Drainage Area = 6.800 acres Runoff CN= 65
Computational Time Increment = .03790 hrs
Computed Peak Time = 12.0509 hrs
Computed Peak Flow = 39.19 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.0502 hrs
Peak Flow, Interpolated Output = 39.15 cfs
DRAINAGE AREA
ID:DAlA
CN = 65
Area = 8.800 acres
S = 5.3846 in
0.2S = 1.0769 in
Cumulative Runoff
-------------------
3.8942 in
2.856 ac-ft
HYG Volume... 2.856 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .28422 hrs (ID: DATA)
Computational Incr, Tm = .03790 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 35.08 cfs
Unit peak time Tp = .18948 hrs
Unit receding limb, Tr = .75792 hrs
Total unit time, Tb = .94740 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:19 PM 9/20/2006
Jot, >:i le: I:ACIVIIAFGi,1i`? 'I'." 1 1 1' I''FLOFE '\I'F.FDA2b?.l
Rain Dir: I:ACIVIL\PGNL-ire i <v.I i i_iL` L],G}I D\
JOB TITLE
---------------------
Project Date: 7/12/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Predeveloped conditions and discharge from 2,10,&100 yr. storm
events in Drainage Area #2 and #3.

SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
D 2
3
N
v
v
Reach 10
•
Out 10 Junc 10
140
I
I
120 1
1001)
80
3
0
60
40
20
0
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Time (hrs)
ouU 1( Pre100

OUT 10 Pre 2
OUT 10 Pre 10
OUT 10 Pre100
Table of Contents
********************** MASTER SUMMARY **********************
Watershed....... Master Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
Holly Springs NC Design Storms ...................... 2.01
*****.**************** TC CALCULATIONS ************+********
DA2 ............. Tc Calcs ........................... 3.01
DA3 ............. Tc Calcs ........................... 3.05
********************** CN CALCULATIONS *******+*************
DA2 ............. Runoff CN-Area ..................... 4.01
DA3 ............. Runoff CN-Area ..................... 4.02
******************** RUNOFF HYDROGRAPHS ********************
Unit Hyd. Equations ................ 5.01
DA2 ............. Pre 10
Unit Hyd. Summary .................. 5.03
DA2 ............. Pre100
Unit Hyd. Summary .................. 5.04
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
TUbIP of Content,-
DA3 ............. Pre 2
Unit Hyd. Summary .................. 5.05
DA3 ............. Pre 1.0
Unit Hyd. Summary .................. 5.06
DA3 ............. Pre100
Unit Hyd. Summary .................. 5.0'7
SIN: 68YXYWGYMXBD
PondPack (10.00.016.00)
4:28 PM
Jacobs Engineering Group
8/8/2006
Type.... Master Network Summary F
Name.... Watershed
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&-.ppw
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Holly Springs NC
Total
Depth Rainfall
Return Event in Type RNF ID
------------
Pre 2 ------
3.6000 -----------------
Synthetic Curve -----------
TypeII 24hr
Pre 10 5.2800 Synthetic Curve TypeII 24hr
Pre100 8.0000 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type
-
--- Event
------ ac-ft Trun
-
- hrs cfs ft ac-ft
-------------
DA2 ---
-
AREA
2 --
--
---- --
.738 ---------
12.2400 -------- -------- ------------
4.30
DA2 AREA 10 2.180 12.1800 19.77
DA2 AREA 100 5.406 12.1700 56.69
DA3 AREA 2 .934 12.2600 5.30
DA3 AREA 10 2.760 12.2000 24.26
DA3 AREA 100 6.844 12.1900 69.70
JUNC 10 JCT 2 .934 12.2600 5.30
JUNC 10 JCT 10 2.760 12.2000 24.26
JUNC 10 JCT 100 6.844 12.1900 69.70
*OUT 10 JCT 2 1.672 12.3000 9.20
*OUT 10 JCT 10 4.940 12.2400 41.93
*OUT 10 JCT 100 12.250 12.2300 121.53
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
4
TypE.... Design Sterm:Faac 2.01 ??-Name.... Holly Springs N?
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Title... Project Date: 7/12/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Predeveloped conditions and discharge from 2,10,&100
yr. storm events in Drainage Area #2 and #3.
DESIGN STORMS SUMMARY
Design Storm File,ID =
Storm Tag Name = Pre 2
Holly Springs NC
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Pre 10
Data Type, File, ID =
Storm Frequency =
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Synthetic Storm TypeII 24hr
10 yr
5.2800 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Pre100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Tc Calcs
Name.... DA2
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Pao( Ci7
...................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: TR-55 Sheet
Mannings n .4000
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .080000 ft/ft
Avg.Velocity .16 ft/sec
Segment #1 Time: .3374 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 300.00 ft
Slope .055000 ft/ft
Unpaved
Avg.Velocity 3.78 ft/sec
Segment #2 Time: .0220 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Shallow
Hydraulic Length 350.00 ft
Slope .011000 ft/ft
Unpaved
Avg.Velocity 1.69 ft/sec
Segment #3 Time: .0575 hrs
------------------------------------------------------------------------
S/N: 68YXYWGYMXBD
PondPack (10.00.016.00)
4:28 PM
Jacobs Engineering Group
8/8/2006
Typ(,.... Tc Ca IcF
Name.... DA2
File.... L•\CIVIL\PONDPACV\PPEDEVELOPED\PREDA2&3.ppw
Segment #4: Tc: TR-55 Channel
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
Avg.Velocity
9.72 ft/sec
Pacc _.02
Segment #4 Time: .0243 hrs
------------------------------------------------------------------------
--------------------------
-------------------------
Total Tc: .4412 hrs
-------------------------
-------------------------
S/N: 68YXYWGYMXBD
PondPack (10.00.016.00)
180.0000 sq.ft
80.00 ft
2.25 ft
.052000 ft/ft
.0600
850.00 ft
4:28 PM
Jacobs Engineering Group
8/8/2006
Type.... Tc Calcs
Name.... DA2
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Pace . O;
-------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
___= SCS TR-55 Sheet Flow ________________
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
___= SCS TR-55 Shallow Concentrated Flow
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Tvpc..._ Tc Calcs Pac, .04
Name.... DA2
File.... I:\CIVIL\PONDPACI<\PRECEVELOPED\PREDA2&3.ppw
___= SCS Channel Flow __________________°______________________________
R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf'O.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
Hydraulic radius
Flow area, sq.ft.
Wetted perimeter, ft
Velocity, ft/sec
Slope, ft/ft
Mannings n
Time of concentration, hrs
Flow length, ft
SIN: 68YXYWGYMXBD
PondPack (10.00.016.00)
4:28 PM
Jacobs Engineering Group
8/8/2006
Type.... Tc Calcs
Name.... DA3
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Pr.o( . W
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .4000
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .050000 ft/ft
Avg.Velocity .14 ft/sec
Segment #1 Time: .4072 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 125.00 ft
Slope .160000 ft/ft
Unpaved
Avg.Velocity 6.45 ft/sec
Segment #2 Time: .0054 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 180.0000 sq.ft
Wetted Perimeter 80.00 ft
Hydraulic Radius 2.25 ft
Slope .050000 ft/ft
Mannings n .0600
Hydraulic Length 660.00 ft
Avg.Velocity 9.53 ft/sec
Segment #3 Time: .0192 hrs
------------------------------------------------------------------------
S/N: 68YXYWGYMXBD
PondPack (10.00.016.00)
4:28 PM
Jacobs Engineering Group
8/8/2006
Typ( .... Tc Ca k e
Name.... DA3
File.... I:\CIVIL\PONDPACK\PhL•'DEVELOPED\PREDA2&3.ppw
Segment #4: Tc: TR-55 Channel
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
Avg.Velocity
6.03 ft/sec
Paqe 3.06 y
Segment #4 Time: .0189 hrs
------------------------------------------------------------------------
Segment #5: Tc: TR-55 Channel
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
Avg.Velocity
9.24 ft/sec
Segment #5 Time: .0089 hrs
------------------------------------------------------------------------
--------------------------
-------------------------
Total Tc: .4596 hrs
-------------------------
-------------------------
180.0000 sq.ft
80.00 ft
2.25 ft
.020000 ft/ft
.0600
410.00 ft
180.0000 sq.ft
80.00 ft
2.25 ft
.047000 ft/ft
.0600
295.00 ft
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Tc Calcs
Name.... DA3
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Pa cc .I? -i
-------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
___= SCS TR-55 Sheet Flow =------------------ ---________________
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4) )
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
___= SCS TR-55 Shallow Concentrated Flow
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Ty)--,c .... Tc Cal cs
Name.... DA3
File.... I:\CIVIL\PONDPACK\PPEDEVELOPED\PREDA2&3.ppw
I aae 3. 08
___= SCS Channel Flow =___------------------------- ____________________
R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
Hydraulic radius
Flow area, sq.ft.
Wetted perimeter, ft
Velocity, ft/sec
Slope, ft/ft
Mannings n
Time of concentration, hrs
Flow length, ft
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Runoff CN-Area
Name.... DA2
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Paa( ! . (I1
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- ---------- ----- ----- ------
Woods - good 55 23.300 55.00
COMPOSITE AREA & WEIGHTED CN ---> 23.300 55.00 (55)
...........................................................................
...........................................................................
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Typc Runoff C'N-Arc
Name.... DAS
Pane 9 . 02 ?yh
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres oC %UC CN
-------------------------------- ---- --------- ----- ----- ------
Woods - good 55 29.500 55.00
COMPOSITE AREA & WEIGHTED CN ---> 29.500 55.00 (55)
...........................................................................
...........................................................................
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 9:28 PM 8/8/2006
Type.... Unit Hyd. Equation=
Name....
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)

DEFINITION OF TERMS: ------------------------------------------------
At = Total area (acres): At = Ai+Ap
Ai = Impervious area (acres)
Ap = Pervious area (acres)
CNi = Runoff curve number for impervious area
CNp = Runoff curve number for pervious area
fLoss = f loss constant infiltration (depth/time)
gKs = Saturated Hydraulic Conductivity (depth/time)
Md = Volumetric Moisture Deficit
Psi = Capillary Suction (length)
hK = Horton Infiltration Decay Rate (time^-1)
fo = Initial Infiltration Rate (depth/time)
fc = Ultimate(capacity)Infiltration Rate (depth/time)
Ia = Initial Abstraction (length)
dt = Computational increment (duration of unit excess rainfall)
Default dt is smallest value of 0.1333Tc, rtm, and th
(Smallest dt is then adjusted to match up with Tp)
UDdt = User specified override computational main time increment
(only used if UDdt is => .1333Tc)
D(t) = Point on distribution curve (fraction of P) for time step t
K = 2 / (1 + (Tr/Tp)): default K = 0.75: (for Tr/Tp = 1.67)
Ks = Hydrograph shape factor
= Unit Conversions * K:
= ((lhr/3600sec) * (lft/12in) * ((5280ft)**2/sq.mi)) * K
Default Ks = 645.333 * 0.75 = 484
Lag = Lag time from center of excess runoff (dt) to Tp: Lag = 0.6Tc
P = Total precipitation depth, inches
Pa(t) = Accumulated rainfall at time step t
Pi(t) = Incremental rainfall at time step t
qp = Peak discharge (cfs) for lin. runoff, for lhr, for 1 sq.mi.
= (Ks * A * Q) / Tp (where Q = tin. runoff, A=sq.mi.)
Qu(t) = Unit hydrograph ordinate (cfs) at time step t
Q(t) = Final hydrograph ordinate (cfs) at time step t
Rai(t)= Accumulated runoff (inches) at time step t for impervious area
Rap(t)= Accumulated runoff (inches) at time step t for pervious area
Rii(t)= Incremental runoff (inches) at time step t for impervious area
Rip(t)= Incremental runoff (inches) at time step t for pervious area
R(t) = Incremental weighted total runoff (inches)
Rtm = Time increment for rainfall table
Si = S for impervious area: Si = (1000/CNi) - 10
Sp = S for pervious area: Sp = (1000/CNp) - 10
t = Time step (row) number
Tc = Time of concentration
Tb = Time (hrs) of entire unit hydrograph: Tb = Tp + Tr
Tp = Time (hrs) to peak of a unit hydrograph: Tp = (dt/2) + Lag
Tr = Time (hrs) of receding limb of unit hydrograph: Tr = ratio of Tp
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Equations Pace 5.02
Name....
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
PRECIPITATION: -----------------------------------------------------------
Column (1): Time for time step t
Column (2): D(t) = Point on distribution curve for time step t
Column (3): Pi(t) = Pa(t) - Pa(t-1): Col.(4) - Preceding Col.(4)
Column (4): Pa(t) = D(t) x P: Col.(2) x P
PERVIOUS AREA RUNOFF (using SCS Runoff CN Method) ------------
Column (5): Rap(t) = Accumulated pervious runoff for time step t
If (Pa(t) is <= 0.2Sp) then use: Rap(t) = 0.0
If (Pa(t) is > 0.2Sp) then use:
Rap(t) = (Col.(4)-0.2Sp)**2 / (Col.(4)+0.8Sp)
Column (6): Rip(t) = Incremental pervious runoff for time step t
Rip(t) = Rap(t) - Rap(t-1)
Rip(t) = Col.(5) for current row - Col.(5) for preceding row.
IMPERVIOUS AREA RUNOFF ---------------------------------------------------
Column (7 & 8)... Did not specify to use impervious areas.
INCREMENTAL WEIGHTED RUNOFF: ---------------------------------------------
Column (9): R(t) _ (Ap/At) x Rip(t) + (Ai/At) x Rii(t)
R(t) _ (Ap/At) x Col.(6) + (Ai/At) x Col.(8)
SCS UNIT HYDROGRAPH METHOD: ----------------------------------------------
Column (10): Q(t) is computed with the SCS unit hydrograph method
using Ro and Quo.
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Summary
Name.... DA2 ?y: tre 10
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Storm... TypeII 24hr Tag: Pre 10
Page 5.03
i/!?
Event: 10 yr
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration = 24.0000 hrs Rain Depth = 5.2800 in
Rain Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
HYG File - ID = - DA2 Pre 10
Tc = .4412 hrs
Drainage Area = 23.300 acres Runoff CN= 55
--------------------------------------------
--------------------------------------------
Computationa] Time Increment = .05883 hrs
Computed Peak Time = 12.1768 hrs
Computed Peak Flow = 19.80 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1802 hrs
Peak Flow, Interpolated Output = 19.77 cfs
--------------------------------------------
DRAINAGE AREA
ID:DA2
CN = 55
Area = 23.300 acres
S = 8.1818 in
0.2S = 1.6364 in
Cumulative Runoff
-------------------
1.1227 in
2.180 ac-ft
HYG Volume... 2.180 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .44119 hrs (ID: DA2)
Computational Incr, Tm = .05883 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(l+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 59.84 cfs
Unit peak time Tp = .29413 hrs
Unit receding limb, Tr = 1.17650 hrs
Total unit time, Tb = 1.47063 hrs
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Summary Page `x.04
Name.... DA2 Tag: Prel00 Event: 100 yr
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Storm... TypelI 24hr Tag: Pre7.00
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
HYG File - ID = - DA2 Pre100
Tc = .4412 hrs
Drainage Area = 23.300 acres Runoff CN= 55
Computational Time Increment = .05883 hrs
Computed Peak Time = 12.1768 hrs
Computed Peak Flow = 56.88 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1702 hrs
Peak Flow, Interpolated Output = 56.69 cfs
DRAINAGE AREA
ID:DA2
CN = 55
Area = 23.300 acres
S = 8.1818 in
0.2S = 1.6364 in
Cumulative Runoff
-------------------
2.7841 in
5.406 ac-ft
HYG Volume... 5.406 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .44119 hrs (ID: DA2)
Computational Incr, Tm = .05883 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 59.84 cfs
Unit peak time Tp = .29413 hrs
Unit receding limb, Tr = 1.17650 hrs
Total unit time, Tb = 1.47063 hrs
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Summary Paae 5.05
Name.... DA3 Par: Pre 2 Event: 2 yr
File.... I:\CIVIL\PONDPACK\PRE'DEVELOPED\PREDA2&3.ppw
Storm... TypeII 24hr Tag: Pre 2
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration = 24.0000 hrs Rain Depth = 3.6000 in
Rain Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
HYG File - ID = - DA3 Pre 2
Tc = .4596 hrs
Drainage Area = 29.500 acres Runoff CN= 55
Computational Time Increment = .06128 hrs
Computed Peak Time = 12.2555 hrs
Computed Peak Flow = 5.31 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2602 hrs
Peak Flow, Interpolated Output = 5.30 cfs
DRAINAGE AREA
ID:DA3
CN = 55
Area = 29.500 acres
S = 8.1818 in
0.25 = 1.6364 in
Cumulative Runoff
-------------------
.3801 in
.934 ac-ft
HYG Volume... .934 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS k****
Time Concentration, Tc = .45958 hrs (ID: DA3)
Computational Incr, Tm = .06128 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 72.73 cfs
Unit peak time Tp = .30639 hrs
Unit receding limb, Tr = 1.22555 hrs
Total unit time, Tb = 1.53193 hrs
i
G x/11
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Summary Page 5.06
Name.... DA3 Tag: Pre 10 Event: i0 yr
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
Storm... TypeII 24hr Tag: Pre 10
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration = 24.0000 hrs Rain Depth = 5.2800 in
Rain Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\PREDEVELOPED\
HYG File - ID = - DA3 Pre 10
Tc = .4596 hrs
Drainage Area = 29.500 acres Runoff CN= 55
Computational Time Increment - .06128 hrs
Computed Peak Time = 12.1942 hrs
Computed Peak Flow = 24.34 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2002 hrs
Peak Flow, Interpolated Output = 24.26 cfs
--------------------------------------------
--------------------------------------------
DRAINAGE AREA
ID:DA3
CN = 55
Area = 29.500 acres
S = 8.1818 in
0.25 = 1.6364 in
Cumulative Runoff
-------------------
1.1227 in
2.760 ac-ft
HYG Volume... 2.760 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .45958 hrs (ID: DA3)
Computational Incr, Tm = .06128 hrs = 0.20000 Tp
Unit Hyd. Shape Factor =
K = 483.43/645.333, K
Receding/Rising, Tr/Tp =
Unit peak, (1P =
Unit peak time Tp =
Unit receding limb, Tr =
Total unit time, Tb =
483.432 (37.46% under rising limb)
.7491 (also, K = 2/(1+(Tr/Tp))
1.6698 (solved from K = .7491)
72.73 cfs
.30639 hrs
1.22555 hrs
1.53193 hrs
SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Type.... Unit Hyd. Summary Page 5.07
Name.... DA3 'rz,g: Pre100 Event: 100 yr
File.... I:\CIVIL\PONDPACK\PREDEVELOPED\PREDA2&3.ppw
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 8.0000 in
I:\CIVIL\PONDPACK\PREDEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\PREDEVELOPED\
- DA3 Pre100
.4596 hrs
29.500 acres Runoff CN= 55
Computational Time Increment = .06128 hrs
Computed Peak Time - 12.1942 hrs
Computed Peak Flow = 69.80 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1902 hrs
Peak Flow, Interpolated Output = 69.70 cfs
DRAINAGE AREA
ID:DA3
CN = 55
Area = 29.500 acres
S = 8.1818 in
0.2S = 1.6364 in
Cumulative Runoff
-------------------
2.7841 in
6.844 ac-ft
HYG Volume... 6.844 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .45958 hrs (ID: DA3)
Computational Incr, Tm = .06128 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 72.73 cfs
Unit peak time Tp = .30639 hrs
Unit receding limb, Tr = 1.22555 hrs
Total unit time, Tb = 1.53193 hrs

SIN: 68YXYWGYMXBD Jacobs Engineering Group
PondPack (10.00.016.00) 4:28 PM 8/8/2006
Job File: I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.PPW
Rain Dir: I:\CIVIL\PONDPACK\POST DEVELOPED\
JOB TITLE
Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, and 100 yr
storm events in drainage area DA2a, DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is less in area
than DA3 (predeveloped). Areas from DA1, 2, & 3 (predeveloped)
create DA1,2,3b in the post developed conditions. This DA 1,2,3b
area is routed through the pond.
Target outflow volumes are determined from the outfall point
OUTDA123. Predeveloped peak discharges from the 1,2,&100 yr strom
events are used for the allowable target discharge rate.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006

0
v
PONDDA123

a"
DA 1,2,3b
A -d REACH DA3a

OUTDA123 Junc 10
250-
2001
150!
VN
3
0
100
50
Hydrograph
OUTDA123
Dev100
OUTDA123 Dev 2
OUTDA123 Dev 10
OUTDA123 Dev100
0
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Time (hrs)
Job File: I:ACIVIL\PONDPACK\PC'S'!' DEVELOPED\POST DA2`TF,'T2.PPW
Rain Dir: I: \CIVIL\PONDFiiCK\P(j:;'1' DEVELOPED\
********************** MASTER SUMMARY **********************
Watershed....... Master Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
Holly Springs NC Design Storms ...................... 2.01
Holly Springs NC Dev 2
Design Storms ...................... 2.02
********************** TC CALCULATIONS ******************+**
DA1,2,39 ........ Tc Calcs ........................... 3.01
DA2A............ Tc Calcs ........................... 3.04
DA3A............ Tc Calcs ........................... 3.07
********************** CN CALCULATIONS *********************
DA1,2,3B........ Runoff CN-Area ..................... 4.01
DA2A............ Runoff CN-Area ..................... 4.02
DA3A............ Runoff CN-Area ..................... 4.03
******************** RUNOFF HYDROGRAPHS ********************
Unit Hyd. Equations ................ 5.01

SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:02 PM
Bentley Systems, Inc.
8/29/2006
Table of Contents
i
DA1,2,3B........ Dev 2
Unit Hyd. Summary .................. 5.03
DA1,2,3B........ Dev 10
Unit Hyd. Summary .................. 5.09
DA1,2,3B........ Dev].00
Unit Hyd. Summary .................. 5.05
DA2A............ Dev 2
Unit Hyd. Summary .................. 5.06
DA2A............ Dev 10
Unit Hyd. Summary .................. 5.07
DA2A............ Dev100
Unit Hyd. Summary .................. 5.08
DA3A............ Dev 2
Unit Hyd. Summary .................. 5.09
DA3A............ Dev 10
Unit Hyd. Summary .................. 5.10
DA3A............ Dev100
Unit Hyd. Summary .................. 5.11
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Table of Contents ii ?lI /?I:t
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Holly Springs NC
Total
Depth Rainfall
Return Event in Type RNF ID
-
----
------------
Dev 2 ------
3.6000 ----------------
Synthetic Curve ----------
-
TypeII 24hr
Dev 10 5.2800 Synthetic Curve TypelI 24hr
Dev100 8.0000 Synthetic Curve TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type
-- Event
------ ac-ft Trun
---------- hrs
---------- cfs ft ac-ft
-------- -------- ------------
-------------
DA1,2,3B ---- --
AREA 2 4.775 12.2200 41.64
DA1,2,3B AREA 10 8.142 12.2200 70.77
DA1,2,3B AREA 100 13.823 12.2200 118.30
DA2A AREA 2 .667 12.3800 3.77
DA2A AREA 10 1.745 12.3300 13.07
DA2A AREA 100 4.028 12.2500 33.13
DA3A AREA 2 1.359 12.2000 11.50
DA3A AREA 10 3.237 12.1900 32.31
DA3A AREA 100 7.031 12.1900 73.82
JUNC 10 JCT 2 1.359 12.2000 11.50
JUNC 10 JCT 10 3.237 12.1900 32.31
JUNC 10 JCT 100 7.031 12.1900 73.82
*OUTDA123 JCT 2 6.800 12.3000 56.69
*OUTDA123 JCT 10 13.124 12.2900 115.44
*OUTDA123 JCT 100 24.883 12.2500 224.45
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak Qpeak Max WSEL
Node ID Type Event ac-ft Trun
-------- -- hrs
--------- cfs ft
-------- --------
------------
PONDDA123 -----
IN ----
POND ------
2 --
4.775 12.2200 41.64
PONDDA123 IN POND 10 8.142 12.2200 70.77
PONDDA123 IN POND 100 13.823 12.2200 118.30
PONDDA123 OUT POND 2 4.775 12.2200 41.64
PONDDA123 OUT POND 10 8.142 12.2200 70.77
PONDDA123 OUT POND 100 13.823 12.2200 118.30
Max
Pond Storage
ac-ft
------------
S/N: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:02 PM
Bentley Systems, Inc.
8/29/2006
Type.... Master Network :umn:r Page 1.02
Name.... Watershed
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
DESIGN STORMS SUMMARY
Design Storm File,ID =
Storm Tag Name = Dev 2
Holly Springs NC
Data Type, File, ID = Synthetic Storm TypeII 24hr.
Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev 10
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.2800 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Design Storms Page 2.01
Name.... Holly Springs NC
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
DESIGN STORMS SUMMARY
Design Storm File,ID = Holly Springs NC
Storm Tag Name = Dev 2
Data Type, File, ID =
Storm Frequency -
Total Rainfall Depth=
Duration Multiplier =
Resulting Duration =
Resulting Start Time=
Synthetic Storm TypeII 24hr
2 yr
3.6000 in
1
24.0000 hrs
.0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev 10
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.2800 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Design Storms Page 2.02
Name.... Holly Springs HC Event: 2 yr
File.... I:\CIVIL\PONDPACK\POS'I' DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev 2
? pI -
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .007500 ft/ft
Avg.Velocity .10 ft/sec
Segment #1 Time: .5780 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 50.00 ft
Slope .007500 ft/ft
Unpaved
Avg.Velocity 1.40 ft/sec
Segment #2 Time: .0099 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 7.0000 sq.ft
Wetted Perimeter 9.50 ft
Hydraulic Radius .74 ft
Slope .008000 ft/ft
Mannings n .0090
Hydraulic Length 1720.00 ft
Avg.Velocity 12.08 ft/sec
Segment #3 Time: .0396 hrs
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: .6275 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs
Name.... DA1,2,3B
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Paae 3.01
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
___= SCS TR-55 Sheet Flow
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
___= SCS TR-55 Shallow Concentrated Flow _______________________________
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs
Name.... DA1,2,3B
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
___= SCS Channel Flow =___
R = Aq / Wp
v = (1.99 * (R**(2/3)) (Sf**-0.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
Hydraulic radius
Flow area, sq.ft.
Wetted perimeter, ft
Velocity, ft/sec
Slope, ft/ft
Mannings n
Time of concentration, hrs
Flow length, ft
Page 3.02
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs Paqe 3.03
Name.... DA1,2,3B
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .010000 ft/ft
Avg.Velocity .11 ft/sec
Segment #1 Time: .5152 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 675.00 ft
Slope .010000 ft/ft
Unpaved
Avg.Velocity 1.61 ft/sec
Segment #2 Time: .1162 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 180.0000 sq.ft
Wetted Perimeter 80.00 ft
Hydraulic Radius 2.25 ft
Slope .052000 ft/ft
Mannings n .0600
Hydraulic Length 700.00 ft
Avg.Velocity 9.72 ft/sec
Segment #3 Time: .0200 hrs
------------------------------------------------------------------------
-------------------------
-------------------------
Total Tc: .6514 hrs
-------------------------
-------------------------
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs
Name.... DA2A
File.... I:\CIVIL\PONDPACK\POS'I' DEVELOPED\POSTDA23TEST2.ppw
Paae 3.04 rl /? l
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
==== SCS TR-55 Sheet Flow =___---
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
_=== SCS TR-55 Shallow Concentrated Flow
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs Page 05
Name.... DA2A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
==== SCS Channel Flow
R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n
Tc = (Lf /
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
V) / (3600sec/hr)
= Hydraulic radius
= Flow area, sq.ft.
= Wetted perimeter, ft
= Velocity, ft/sec
= Slope, ft/ft
= Mannings n
= Time of concentration, hrs
= Flow length, ft
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs
Name.... DA2A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TFST2.ppw
Page 3.06 b I A ?e
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .4000
Hydraulic Length 200.00 ft
2yr, 24hr P 3.6000 in
Slope .050000 ft/ft
Avg.Velocity .14 ft/sec
Segment #1 Time: .4072 hrs
-------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 125.00 ft
Slope .160000 ft/ft
Unpaved
Avg.Velocity 6.45 ft/sec
Segment #2 Time: .0054 hrs
----- ------------------------------------------------------------------
Segment #3: Tc:
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
TR-55 Channel
180.0000 sq.ft
80.00 ft
2.25 ft
.050000 ft/ft
.0600
660.00 ft
Avg.Velocity 9.53 ft/sec
Segment #3 Time: .0192 hrs
------------------------------------------------------------------------
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Tc Calcs
Name.... DA3A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Segment #4: Tc:
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
TR-55 Channel
7.0000 sq.ft
9.50 ft
.74 ft
.007500 ft/ft
.0090
100.00 ft
Avg.Velocity 11.70 ft/sec
Page 3.07
Segment #4 Time: .0024 hrs
------------------------------------------------------------------------
Segment #5: Tc: TR-55 Channel
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
180.0000 sq.ft
80.00 ft
2.25 ft
.020000 ft/ft
.0600
410.00 ft
Avg.Velocity 6.03 ft/sec
Segment #5 Time: .0189 hrs
------------------------------------------------------------------------
Segment #6: Tc:
Flow Area
Wetted Perimeter
Hydraulic Radius
Slope
Mannings n
Hydraulic Length
TR-55 Channel
180.0000 sq.ft
80.00 ft
2.25 ft
.047000 ft/ft
.0600
295.00 ft
Avg.Velocity 9.24 ft/sec
Segment #6 Time: .0089 hrs
------------------------------------------------------------------------
Total Tc: .4620 hrs
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:02 PM
Bentley Systems, Inc.
8/29/2006
Type.... Tc Calcs
Name.... DA3A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
/I?-
Page 3.08
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------
SCS TR-55 Sheet Flow
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, o
_=== SCS TR-55 Shallow Concentrated Flow
Unpaved surface:
V = 16.1345 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr).
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:02 PM
Bentley Systems, Inc.
8/29/2006
Type.... Tc Calcs
Name.... DA3A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Paqe 3.09
___= SCS Channel Flow
R = Aq / Wp
V = (1.49 * (R**(2/3)) (Sf**-0.5)) / n
Tc = (Lf /
Where: R
Aq
Wp
V
Sf
n
Tc
Lf
V) / (3600sec/hr)
= Hydraulic radius
= Flow area, sq.ft.
= Wetted perimeter, ft
= Velocity, ft/sec
= Slope, ft/ft
= Mannings n
= Time of concentration, hrs
= Flow length, ft
SIN: 68YXYWGYMXBD
Bentley PondPack (10.00.023.00)
5:02 PM
Bentley Systems, Inc.
8/29/2006
Type.... Tc Ca.lcs
Name.... DA3A
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\P0STDA23TEST2.ppw
Page 3.10
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open space (Lawns,parks etc.) - Goo 61 8.700 61.00
Impervious Areas - Paved parking to 98 17.500 98.00
COMPOSITE AREA & WEIGHTED CN ---> 26.200 85.71 (86)
...........................................................................
...........................................................................
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Runoff CN-Area
Name.... DA1,2,3B
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
PagE: 9 . 01
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C RUC CN
-------------------------------- ---- --------- ----- ----- ------
Open space (Lawns,parks etc.) - Goo 61 8.800 61.00
Woods - good 55 6.200 55.00
COMPOSITE AREA & WEIGHTED CN ---> 15.000 58.52 (59)
...........................................................................
...........................................................................
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Runoff CN-Area Page 4.02 l'
Name.... DA2A
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description
------
---
-
---
- CN acres oC %UC CN
-
-
-------
-
--------
Open space (Lawns,parks etc.) - Goo ----
61 ---------
10.000 ----- ----- ------
61.00
Impervious Areas - Paved parking to 98 3.000 98.00
Woods - good 55 10.000 55.00
COMPOSITE AREA S WEIGHTED CN ---> 23.000 63.22 (63)
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Runoff CN-Area Paqe 4.03 `
Name.... DA3A
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
DEFINITION OF TERMS: ------------------------------------------------
At = Total area (acres): At = Ai+Ap
Ai = Impervious area (acres)
Ap = Pervious area (acres)
CNi = Runoff curve number for impervious area
CNp = Runoff curve number for pervious area
fLoss = f loss constant infiltration (depth/time)
gKs = Saturated Hydraulic Conductivity (depth/time)
Md = Volumetric Moisture Deficit
Psi = Capillary Suction (length)
hK = Horton Infiltration Decay Rate (time^-1)
fo = Initial Infiltration Rate (depth/time)
fc = Ultimate(capacity)Infiltration Rate (depth/time)
Ia = Initial Abstraction (length)
dt = Computational increment (duration of unit excess rainfall)
Default dt is smallest value of 0.1333Tc, rtm, and th
(Smallest dt is then adjusted to match up with Tp)
UDdt = User specified override computational main time increment
(only used if UDdt is => .1333Tc)
D(t) = Point on distribution curve (fraction of P) for time step t
K = 2 / (1 + (Tr/Tp)): default K = 0.75: (for Tr/Tp = 1.67)
Ks = Hydrograph shape factor
Unit Conversions * K:
_ ((lhr/3600sec) * (lft/12in) * ((5280ft)**2/sq.mi)) * K
Default Ks = 645.333 * 0.75 = 484
Lag = Lag time from center of excess runoff (dt) to Tp: Lag = 0.6Tc
P = Total precipitation depth, inches
Pa(t) = Accumulated rainfall at time step t
Pi(t) = Incremental rainfall at time step t
qp = Peak discharge (cfs) for lin. runoff, for lhr, for 1 sq.mi.
_ (Ks * A * Q) / Tp (where Q = lin. runoff, A=sq.mi.)
Qu(t) = Unit hydrograph ordinate (cfs) at time step t
Q(t) = Final hydrograph ordinate (cfs) at time step t
Rai(t)= Accumulated runoff (inches) at time step t for impervious area
Rap(t)= Accumulated runoff (inches) at time step t for pervious area
Rii(t)= Incremental runoff (inches) at time step t for impervious area
Rip(t)= Incremental runoff (inches) at time step t for pervious area
R(t) = Incremental weighted total runoff (inches)
Rtm = Time increment for rainfall table
Si = S for impervious area: Si = (1000/CNi) - 10
Sp = S for pervious area: Sp = (1000/CNp) - 10
t = Time step (row) number
Tc = Time of concentration
Tb = Time (hrs) of entire unit hydrograph: Tb = Tp + Tr
Tp = Time (hrs) to peak of a unit hydrograph: Tp = (dt/2) + Lag
Tr = Time (hrs) of receding limb of unit hydrograph: Tr = ratio of Tp
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Equations Page 5.01
Name....
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
SCS UNIT HYDROGRAPH METHOD
(Computational Notes)
PRECIPITATION: --------------------------------
---------------------------
Column (1): Time for time step t
Column (2): D(t) = Point on distribution curve for time step t
Column (3): Pi(t) = Pa(t) - Pa(t-1): Col.(4) - Preceding Col.(4)
Column (9): Pa(t) = D(t) x P: Col.(2) x P
PERVIOUS AREA RUNOFF (using SCS Runoff CN Method) -----------
Column (5): Rap(t) = Accumulated pervious runoff for time step t
If (Pa(t) is <= 0.2Sp) then use: Rap(t) = 0.0
If (Pa(t) is > 0.2Sp) then use:
Rap(t) = (Co1.(4)-0.2Sp)**2 / (Col.(4)+0.8Sp)
Column (6): Rip(t) = Incremental pervious runoff for time step t
Rip(t) = Rap(t) - Rap(t-1)
Rip(t) = Col.(5) for current row - Col.(5) for preceding row.
IMPERVIOUS AREA RUNOFF --------------------------------------------------
Column (7 & 8)... Did not specify to use impervious areas.
INCREMENTAL WEIGHTED RUNOFF: ----------------------------------------------
Column (9): R(t) = (Ap/At) x Rip(t) + (Ai/At) x Rii(t)
R(t) = (Ap/At) x Col.(6) + (Ai/At) x Col.(8)
SCS UNIT HYDROGRAPH METHOD: ----------------------------------------------
Column (10): Q(t) is computed with the SCS unit hydrograph method
using Ro and Quo.

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Equations Paap 02
Name....
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration = 24.0000 hrs Rain Depth = 3.6000 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = work pad.hyg - DA1,2,3B Dev 2
Tc = .6275 hrs
Drainage Area = 26.200 acres Runoff CN = 86
Computational Time Increment = .08366 hrs
Computed Peak Time = 12.2148 hrs
Computed Peak Flow = 41.64 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2202 hrs
Peak Flow, Interpolated Output = 41.64 cfs
DRAINAGE AREA
ID:DA1,2,3B
CN = 86
Area = 26.200 acres
S = 1.6279 in
0.2S = .3256 in
Cumulative Runoff
-------------------
2.1871 in
4.775 ac-ft
HYG Volume... 4.775 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .62747 hrs (ID: DA1,2,3B)
Computational Incr, Tm = .08366 hrs = 0.20000 Tp
Unit Hyd. Shape Factor
K = 483.43/645.333, K
Receding/Rising, Tr/Tp
Unit peak, qp
Unit peak time Tp
Unit receding limb, Tr
Total unit time, Tb
483.432 (37.46% under rising limb)
.7491 (also, K = 2/(1+(Tr/Tp))
1.6698 (solved from K = .7491)
47.31 cfs
.41832 hrs
1.67326 hrs
2.09158 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley Pond Pack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.03
Name.... DA1,2,3B ;'a?: !)ev z Event: 2 yr
F'ile.... I:\CIVIL\PONDPAW POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev 2
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 5.2800 in
I:\CIVIL\PONDPACK\POST DEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\POST DEVELOPED\
work pad.hyg - DA1,2,3B Dev 10
.6275 hrs
26.200 acres Runoff CN= 86
Computational Time Increment - .08366 hrs
Computed Peak Time = 12.2148 hrs
Computed Peak Flow = 70.81 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2202 hrs
Peak Flow, Interpolated Output = 70.77 cfs
DRAINAGE AREA
ID:DA1,2,3B
CN = 86
Area = 26.200 acres
S = 1.6279 in
0.25 = .3256 in
Cumulative Runoff
-------------------
3.7291 in
8.142 ac-ft
HYG Volume... 8.142 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .62747 hrs (ID: DA1,2,3B)
Computational Incr, Tm = .08366 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(l+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 47.31 cfs
Unit peak time Tp = .41832 hrs
Unit receding limb, Tr = 1.67326 hrs
Total unit time, Tb = 2.09158 hrs

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.04
Name.... DA1,2,3B Tag: Dev 10 Event: 10 yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev 10
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = work _pad.hyg - DA1,2,3B Dev100
Tc = .6275 hrs
Drainage Area = 26.200 acres Runoff CN= 86
Computational Time Increment = .08366 hrs
Computed Peak Time = 12.2148 hrs
Computed Peak Flow = 118.41 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2202 hrs
Peak Flow, Interpolated Output = 118.30 cfs
---------------------------------------------
--------------------------------------------
DRAINAGE AREA
ID:DA1,2,3B
CN = 86
Area = 26.200 acres
S = 1.6279 in
0.25 = .3256 in
Cumulative Runoff
-------------------
6.3314 in
13.824 ac-ft
HYG Volume... 13.823 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .62747 hrs (ID: DA1,2,3B)
Computational Incr, Tm = .08366 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 47.31 cfs
Unit peak time Tp = .41832 hrs
Unit receding limb, Tr = 1.67326 hrs
Total unit time, Tb = 2.09158 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.05
Name.... DA7.,2,3B 7c:c: Dev100 Event: 100 yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev100

SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 3.6000 in
I:\CIVIL\PONDPACK\POST DEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\POST DEVELOPED\
work pad.hyg - DA2A Dev 2
.6514 hrs
15.000 acres Runoff CN= 59
Computational Time Increment = .08685 hrs
Computed Peak Time = 12.4194 hrs
Computed Peak Flow - 3.78 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.4102 hrs
Peak Flow, Interpolated Output = 3.78 cfs
DRAINAGE AREA
ID:DA2A
CN = 59
Area = 15.000 acres
S - 6.9492 in
0.25 = 1.3898 in
Cumulative Runoff
-------------------
.5333 in
.667 ac-ft
HYG Volume... .667 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .65137 hrs (ID: DA2A)
Computational Incr, Tm = .08685 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.468 under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 26.09 cfs
Unit peak time Tp = .43424 hrs
Unit receding limb, Tr = 1.73697 hrs
Total unit time, Tb = 2.17122 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Paae '5.06
Name.... DA2A Tag: Dev 2 Event: 2 yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev 2
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration = 24.0000 hrs Rain Depth = 5.2800 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = work pad.hyg - DA2A Dev 10
Tc = .6514 hrs
Drainage Area = 15.000 acres Runoff CN= 59
Computational Time Increment = .08685 hrs
Computed Peak Time = 12.3325 hrs _
Computed Peak Flow = 13.08 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.3302 hrs
Peak Flow, Interpolated Output = 13.07 cfs
DRAINAGE AREA
ID:DA2A
CN = 59
Area = 15.000 acres
S = 6.9492 in
0.2S = 1.3898 in
Cumulative Runoff
-------------------
1.3962 in
1.745 ac-ft
HYG Volume... 1.745 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .65137 hrs (ID: DA2A)
Computational Incr, Tm = .08685 hrs = 0.20000 Tp
Unit Hyd. Shape Factor
K = 483.43/645.333, K
Receding/Rising, Tr/Tp
Unit peak, qp
Unit peak time Tp
Unit receding limb, Tr
Total unit time, Tb
483.432 (37.46% under rising limb)
.7491 (also, K = 2/(1+(Tr/Tp))
1.6698 (solved from K = .7491)
26.09 cfs
.43424 hrs
1.73697 hrs
2.17122 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.07
Name .... DA2A I;ev 10 Event: 1.0 yr
File.... I:\CIVIL\PONDPACK\I?OS7' DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr 'fag: Dev 10
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 8.0000 in
I:\CIVIL\PONDPACK\POST DEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\POST DEVELOPED\
work pad.hyg - DA2A Dev100
.6514 hrs
15.000 acres Runoff CN= 59
Computational Time Increment = .08685 hrs
Computed Peak Time = 12.2457 hrs
Computed Peak Flow = 33.13 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2502 hrs
Peak Flow, Interpolated Output = 33.13 cfs
DRAINAGE AREA
ID:DA2A
CN = 59
Area = 15.000 acres
S = 6.9492 in
0.2S = 1.3898 in
Cumulative Runoff
-------------------
3.2225 in
4.028 ac-ft
HYG Volume... 4.028 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .65137 hrs (ID: DA2A)
Computational Incr, Tm = .08685 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 26.09 cfs
Unit peak time Tp = .43424 hrs
Unit receding limb, Tr = 1.73697 hrs
Total unit time, Tb = 2.17122 hrs

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.08
Name.... DA2A Tag: Dev100 Event: 100 yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr Tag: Dev100
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 2 year storm
Duration
Rain Dir
Rain File -ID
Unit Hyd Type
HYG Dir
HYG File - ID
Tc
Drainage Area
24.0000 hrs Rain Depth = 3.6000 in
I:\CIVIL\PONDPACK\POST DEVELOPED\
- TypeII 24hr
Default Curvilinear
I:\CIVIL\PONDPACK\POST DEVELOPED\
work pad.hyg - DA3A Dev 2
.4620 hrs
23.000 acres Runoff CN= 63
--------------------------------------------
--------------------------------------------
Computational Time Increment = .06159 hrs
Computed Peak Time = 12.1956 hrs
Computed Peak Flow = 11.52 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.2002 hrs
Peak Flow, Interpolated Output = 11.50 cfs
--------------------------------------------
--------------------------------------------
DRAINAGE AREA
ID:DA3A
CN = 63
Area = 23.000 acres
S = 5.8730 in
0.2S = 1.1746 in
Cumulative Runoff
-------------------
.7089 in
1.359 ac-ft
HYG Volume... 1.359 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .46196 hrs (ID: DA3A)
Computational Incr, Tm = .06159 hrs = 0.20000 Tp
Unit Hyd. Shape Fact or = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 56.41 cfs
Unit peak time Tp = .30797 hrs
Unit receding limb, Tr = 1.23188 hrs
Total unit time, Tb = 1.53985 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Page 5.09
Name .... DA3A 'i ?I u : Dev 2 Event: 2 yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Storm... TypeII 24hr. Tag: Dev 2
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 10 year storm
Duration = 24.0000 hrs Rain Depth = 5.2800 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = work_pad.hyg - DAM Dev 10
Tc = .4620 hrs
Drainage Area = 23.000 acres Runoff CN= 63
--------------------------------------------
--------------------------------------------
Computational Time Increment = .06159 hrs
Computed Peak Time = 12.1956 hrs
Computed Peak Flow = 32.39 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1902 hrs
Peak Flow, Interpolated Output = 32.31 cfs
DRAINAGE AREA
ID:DA3A
CN = 63
Area = 23.000 acres
S = 5.8730 in
0.25 = 1.1746 in
Cumulative Runoff
-------------------
1.6891 in
3.237 ac-ft
HYG Volume... 3.237 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .46196 hrs (ID: DA3A)
Computational Incr, Tm = .06159 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 56.41 cfs
Unit peak time Tp = .30797 hrs
Unit receding limb, Tr = 1.23188 hrs
Total unit time, Tb = 1.53985 hrs

SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Type.... Unit Hyd. Summary Paae 5.10
Name.... DA3A 'rag: Dev 1U Event: 10 Yr
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
SCS UNIT HYDROGRAPH METHOD
STORM EVENT: 100 year storm
Duration = 24.0000 hrs Rain Depth = 8.0000 in
Rain Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
Rain File -ID = - TypeII 24hr
Unit Hyd Type = Default Curvilinear
HYG Dir = I:\CIVIL\PONDPACK\POST DEVELOPED\
HYG File - ID = work pad.hyg - DA3A Dev100
Tc = .4620 hrs
Drainage Area = 23.000 acres Runoff CN= 63
Computational Time Increment = .06159 hrs
Computed Peak Time = 12.1956 hrs
Computed Peak Flow = 73.85 cfs
Time Increment for HYG File = .0100 hrs
Peak Time, Interpolated Output = 12.1902 hrs
Peak Flow, Interpolated Output = 73.82 cfs
DRAINAGE AREA
ID:DA3A
CN = 63
Area = 23.000 acres
S = 5.8730 in
0.25 = 1.1746 in
Cumulative Runoff
-------------------
3.6687 in
7.032 ac-ft
HYG Volume... 7.031 ac-ft (area under HYG curve)
***** SCS UNIT HYDROGRAPH PARAMETERS *****
Time Concentration, Tc = .46196 hrs (ID: DAM)
Computational Incr, Tm = .06159 hrs = 0.20000 Tp
Unit Hyd. Shape Factor = 483.432 (37.46% under rising limb)
K = 483.43/645.333, K = .7491 (also, K = 2/(1+(Tr/Tp))
Receding/Rising, Tr/ Tp = 1.6698 (solved from K = .7491)
Unit peak, qp = 56.41 cfs
Unit peak time Tp = .30797 hrs
Unit receding limb, Tr = 1.23188 hrs
Total unit time, Tb = 1.53985 hrs
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 5:02 PM 8/29/2006
Job File: I: ACIVIL\PONDPP.CK\P0>,T PFVELOPED\POST DA 23TFPPW
Rain Dir: 1: \CIVIL\POND1,ACK\i'US'i DEVELOPED\

JOB TITLE
--------------------------
Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, and 100 yr
storm events in drainage area DA2a, DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is less in area
than DA3 (predeveloped). Areas from DA1, 2, & 3 (predeveloped)
create DA1,2,3b in the post developed conditions. This DA 1,2,3b
area is routed through the pond.
Target outflow volumes are determined from the outfall point
OUTDA123. Predeveloped peak discharges from the 1,2,&100 yr strom
events are used for the allowable target discharge rate.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:52 PM 8/29/2006
Type.... Target Outflow Volume EstimaCes
Name.... PONDDA123
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
DETENTION STORAGE ESTIMATES -- Target Peak Outflow Rate
Return Peak In Target Lower
Events
-------- (cfs)
----------- (cfs)
---------- (ac-f t)
--

2
56.693
9.198 ------
2.453
10 115.440 41.933 2.734
100 224.448 121.526 2.961
CALCULATION TIME RANGES
Lower
Return From To
Events (hrs) (hrs)
--------
2 -------
11.82 ------
13.43
10 11.95 12.79
100 12.01 12.59
Page 0.01
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:52 PM 8/29/2006
I iydrogr?.pl, I C' l / i , / '
OU1 DA123 Dev100
250-
2001
150
U
3
0
LL
100
50
I
0
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Time (hrs)
Minimum Est 100
OUTDA123 Dev100
Hydrograph
OUTDA123 Dev 10
120
100
80
in
w
U
3 60
0
U-
40
1
20
Minimum Est 10
?- OUTDA123 Dev 10
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Time (hrs)
hydrog ri.
OUTDA123 Dev 2
60
50
40
in
U
3 30
0
6=
20
10
Minimum Est 2
-'? OUTDA123 Dev 2
Time (hrs)
0
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Section D
Calc#1 Pond Outlet Structure/
Emergency Spillway
Job File: I: \CIVIL\PONDPACK\ POST DEVELOPED\POSTDA23TEST2.PPW
Rain Dir: I:\CIVIL\PONDPACK\POST DEVELOPED\

JOB TITLE
---------------------------
--------------------------
Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10, and 100 yr
storm events in drainage area DA2a, DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is less in area
than DA3 (predeveloped). Areas from DA1, 2, & 3 (predeveloped)
create DA1,2,3b in the post developed conditions. This DA 1,2,3b
area is routed through the pond.
Target outflow volumes are determined from the outfall point
OUTDA123. Predeveloped peak discharges from the 1,2,&100 yr strom
events are used for the allowable target discharge rate.
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Job File: I:\CIVIL\PONDPACK\POST DEVELOPED\ POSTDA23TFST2. PPW
Rain Dir: I:ACIVIL\PONDPACK\POST DEVELOPED\
******************** OUTLET STRUCTURES *********************
Outlet DA123b... Outlet Input Data .................. 1.01
Composite Rating Curve ............. 1.06
060
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Table of Contents
i
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 316.70 ft
Increment = .10 ft
Max. Elev.= 320.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Inlet Box R1 ---> TW 319.200 320.000
Inlet Box R2 ---> TW 319.200 320.000
Inlet Box RO ---> TW 319.200 320.000
Orifice-Circular 00 ---> TW 316.750 320.000
TW SETUP, DS Channel
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Type.... Outlet Input Data Page 1.01 1040
Name.... Outlet DA123b I
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
OUTLET STRUCTURE INPUT DATA
Structure ID = R1
Structure Type =
------------------- Inlet Box
--

# of Openings - ---------------
1
Invert Elev. = 319.20 ft
Orifice Area = 3.6000 sq.ft
Orifice Coeff. _ .600
Weir Length = 4.50 ft
Weir Coeff. = 3.330
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Orifice H to crest= Yes
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Type.... Outlet Input Data Page 1.02
Name.... Outlet DA123b
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a. is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
OUTLET STRUCTURE INPUT DATA
Structure ID = R2
Structure Type =
------
- Inlet Box
-
-
----------
# of Openings = -----------------
1
Invert Elev. - 319.20 ft
Orifice Area = 2.4000 sq.ft
Orifice Coeff. _ .600
Weir Length = 3.00 ft
Weir Coeff. = 3.330
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Orifice H to crest= Yes
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Type.... Outlet Input Data Page 1.03
(ID?(2`?
Name.... Outlet DA123b
?... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
OUTLET STRUCTURE INPUT DATA
Structure ID = RO
Structure Type =
-------
--- Inlet Box
----
-----
# of Openings = -----------------
1
Invert Elev. = 319.20 ft
Orifice Area = 3.6000 sq.ft
Orifice Coeff. _ .600
Weir Length = 9.50 ft
Weir Coeff. - 3.330
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Orifice H to crest= Yes
Structure ID = 00
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 316.75 ft
Diameter = 1.0000 ft
Orifice Coeff. _ .600
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Type.... Outlet Input Data
Name.... Outlet DA123b
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge --- ----------------------
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- ----- Contributing Structures
------------
-

316.70
.00
Free
Outfall
None -
------------
contributing
316.75 .00 Free Outfall None contributing
316.80 .00 Free Outfall 00
316.90 .07 Free Outfall 00
317.00 .16 Free Outfall 00
317.10 .39 Free Outfall 00
317.20 .62 Free Outfall 00
317.30 .91 Free Outfall 00
317.40 1.23 Free Outfall 00
317.50 1.59 Free Outfall 00
317.60 1.97 Free Outfall 00
317.70 2.38 Free Outfall 00
317.80 2.80 Free Outfall 00
317.90 3.05 Free Outfall 00
318.00 3.27 Free Outfall 00
318.10 3.49 Free Outfall 00
318.20 3.68 Free Outfall 00
318.30 3.87 Free Outfall 00
318.40 4.05 Free Outfall 00
318.50 4.23 Free Outfall 00
Page 1.05
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
Type.... Composite Rating Curvu
Name.... Outlet DA123b
Page 1.06
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge - ---- ---- ---- -----
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- ----- Contr
------ ibuting
-----
-- Structures

318.60
4.39
Free
Outfall
00 - ------------
318.70 4.55 Free Outfall 00
318.80 4.71 Free Outfall 00
318.90 4.86 Free Outfall 00
319.00 5.00 Free Outfall 00
319.10 5.14 Free Outfall 00
319.20 5.28 Free Outfall R1 +R2 +RO +00 G1=
319.30
319.40 6.68
9.12 Free
Free Outfall
Outfall R1
Rl +R2
+R2 +RO
+RO +00
+00
L 'L?/?2L`
?_q 2 L
119.50 12.24 Free Outfall R1 +R2 +RO +00 r
319.60 15.90 Free Outfall R1 +R2 +RO +00
319.70 20.04 Free Outfall Rl +R2 +RO +00
319.80 24.61 Free Qutfall R1 +R2 +RO +00
319.90
320 29.56
34
86 Free
F Outfall
tf
ll
O R1
R1 +R2
R2 +RO
O +00
00
&A-Y04r GV
16 P
4
Y ? ?
. QQ
, , reg a
u + +R + -
-
r S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PM 8/31/2006
320
319
F
v
5 318
w
317
3161
0
Elev. vs. Flow
Outlet DA123b
10 20 30
Flow (cfs)
40
Outlet DA123b
Type.... Target Outflow Volume Estimates Page 0.01
Name.... PONDDA123
File.... I:\CIVIL\PONDPACK\POST DEVELOPED\POSTDA23TEST2.ppw
DETENTION STORAGE ESTIMATES -- Target Peak Outflow Rate
Return Peak In Target Lower
Events (cfs) (cfs) (ac-ft)
--------
10 ---56.693--
115.440 ---9.198---- 2.4 @>`L319.4 PejD 1lOL Z,!rttF"r 61C•
41.933 2.734 14-520.0 Fbr1D VOL = 3, 2Urc r O?
100 224.448 121.526 1
CALCULATION TIME RANGES
Lower
Return From To
Events (hrs) (hrs)
--------
2 -------
11.82 ------
13.43
10 11.95 12.79
100 12.01 12.59
I 1 +/1 ez 51,
SIN: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 4:52 PM 8/29/2006
i
HOLLY SPRINGS N.C.
PN 22COl 16S CAMPUS A POND "BORROW AREA" CALCULATIONS 8/30/2006
Peak Attenuat ion Stora ge
BO RROW END AREA
AREA DIST AVG. AREA s VOLUME (c
F316.75 26726
0.65 33373 21692.45
317.4 40020
1.6 42941.5 68706.4
319 45863
0.4 46436 18574,4
319.4 47009
0.6 47869 28721.4
320 48729

TOTALS 170620 137695
AC-FT 3.16

NOTE
1. Volume ava ilable 3.1 6 AC-FT is greater than volume re quired of 2.73 AC-FT.
10 r redevelo ed dischar ed/10 r post developed stored).

2. Elevation 314 is the water quality permanent pool elevation.
Elevation 316.75 is top of storage for water 1" water quality pool

3. Elevation 320 is the invert elevation of the emergency s pillway.

Profile
Scenario: Base
Pond Outlet
Riser
Sta: 0+00 ft
Inv Out: 308.00 ft
D;-, a)n nn R
320.00
315.00
310.00 Elevation (ft)
- 1 305.00
300.00
2+00
Station (ft)
Title: Aardvark Holly springs Project Engineer: EJK
i:\civil\pondpack\pondoutlet.stm StormCAD v5.6 [05.06.012.00]
08/31/06 01:14:56 ntley Systems, Inc. Haestad Methods Solution Center Watertown, CT 05795 USA [phone] Page 1 of 1
0+00 1+00
Calculation Results Summary
Scenario: Base
>>>> Info: Subsurface Network Rooted by: 0-1
»» Info: Subsurface Analysis iterations: 1
>>>> Info: Convergence was achieved.
CALCULATION SUMMARY FOR SURFACE NETWORKS
I Label I Inlet I Inlet I Total I Total I Capture I Gutter I Gutter I
I I Type I Intercepted I Bypassed I Efficiency I Spread I Depth I
i I I Flow I Flow I (?) I (ft) (ft) I
i I I (cfs) I (cfs) I
----
- I
-
---
----- I
-------- I
--------I
I-------I--------------- I----------------------------------- I
( Riser I Generic Inlet I Generic Default 100% 1 0.00
-------------------------------------------------------------- ---
-
- I
0.00 1
----------- --
-
I
100.0 I
------------- 0.00 I
--------- 0.00 1
---------
CALCULATION SUMMARY FOR SUBSURFACE NETWORK WITH ROOT: 0-1
I Label I Number I Section I Section I Length I Total I Average I Hydraulic I Hydraulic I
I I of I Size I Shape I (ft) I System I Velocity I Grade I Grade I
I I Sections I I Flow I (ft/s) I Upstream I Downstream I
I I I I I I (cfs) I
-
-
---
- I
---------- (ft)
----------- I (ft) I
------------I
I-------I---------- I--------- I---------
------- I
-
--- I
I
I P-1 1 1 1 30 inch I Circular 1 160.00 1 34.90 1
----------------------------------------------------------- I
16.67 1
----------- 310.01
----------- I
I 301.11 I
--------------
I Label I Total I Ground I Hydraulic I Hydraulic I
I I System I Elevation I Grade I Grade I
I I Flow I (ft) I Line In I Line Out I
I I (cfs) I
-
----
-------
----------- I (ft) I
----------- I (ft) I
-----------I
I
-
I-
- I
10-1 I 34.90 1 314.00 I
1 300.00 1 300.00 1
1 Riser 1 34.90 1
------------------ 320.00
----------- 1 310.54 1
------------- 310.01 1
------------
Completed: 08/31/2006 01:12:08 PM
Title: Aardvark Holly springs Project Engineer: EJK
is\civil\pondpack\pondoutlet.stm StormCAD v5.6 [05.06.012.00]
08/31/06 01:14:3ntley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone] Page 1 of 1

Wet Detention Pond Emergency Spillway
Project Description
Friction Method Manning Formula
Solve For Discharge
Input Data
Roughness Coefficient 0.030
Channel Slope 0.07000 ft/ft
Normal Depth 1.00 ft
Left Side Slope 3.00 ft/ft (H:V)
Right Side Slope 3.00 ft/ft (H:V)
Bottom Width 15.00 ft
Results
Discharge 210.68 ft3/s
Flow Area 18.00 ft2
Wetted Perimeter 21.32 ft
Top Width 21.00 ft
Critical Depth 1.63 ft
Critical Slope 0.01233 ft/ft
Velocity 11.70 ft/s
Velocity Head 2.13 ft
Specific Energy 3.13 ft
Froude Number 2.23
Flow Type Supercritical
GVF;Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GV? "Outpul"t, Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.00 ft
Critical Depth 1.63 ft
Channel Slope 0.07000 ft/ft
Critical Slope 0.01233 ft /ft

Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster (08.01.066.00]
9121/2006 10:48:62 AM 27 Slemons Company Drive Suite 200 W Watertown, CT 06796 USA [phone] Page 1 of 1

Appendix A
Calc. #1 Pre & Post Conditions Maps
Wet Detention Pond Plan
r----------------------------
,-,:' I
\A
I
I
I
I
- I
I

- - - - - -- - - - -- - -- -

=z' - RA'
A
C
/
i I

i
?v art xcvrsrur ws wrw .wAwm rm• wrz

1.

/ LEGEND

'ti ?. ????••? .u¢uvu rurAW
y

LZ

Me sEE ? ? \ 0) NO VA RT I S
-__.._ ??. ..- --_. -. _ -..-?• rwvertnt vttIYESA OUCnosrres
rnoca USFCC
w?wc K. arrnn.¢ ouwc r.c wn; nnc .
// raum rp n[.c. STORNwATER MANAGEMENT
PRE-DE`/ELOPMENT PLAN
M01 K
?r KR.
O{WIN
KrIF P.O.ICCI rMrlfA wrw4 M»!OI rr[Y
22COT1-XX 00-C-40-99-11 A
____-_ um n[ ne. »nc-co[twr r!w.wc
i
--- -------- -------------------------------- ---------------------- l
LAND UK DESONATNNI
O saw

K
?
N

O
b6 fi l,+

yygs i

0) NOVARTIS

- ? ? - - ? NOVARTI$ vACCM6 A DuG!ASMS

USFCC
Rn art Rns1ow oounnw r,weto a• nrz u nxnio+ naom w?.c o. .uw a ouw y .+.[ nrz 'mc.
?? Is1?ED /q R(Kw ??5 mvuM STORMWATER MANAGEMENT
POST DEVELOPMENT PLAN
Q?

; acRC woetr nwaw oiwinc aRO wn
3 '
T1-xx
22CO 00-G-RO-99-12 A

--------------------------------------------------------------------------------
Jv '
CGENERAL NOTES
°n...w. m....s
AN,
n ?\ / ? - i Tr®w. wo w.?
I
I x \` deb _ ?.
'E 32 ?
?< \ \ a
?
?? I
- r I
\ \ / aanur ld . "? / - ??????p?. 1660 M'on Roof
I ?> \ / ? roa ?(/ ? ? ?MNiV??7 Gnunrio4. Onw 431/0 I
X,
NO VART I S
/
NOVARTIS VACCINES& DIAGNOSTICS
,\ / ? / ?? u504EEN OA6 PN[wwT
I , / ., '. \ ? ? l///? '/ ( ? ?' NOM.T SPRIGi NORMGVtpM,,
PROJECT: USFCC
I RE DATE REMS oN O[xRpnO •PPROVEn REV O.rE REV yon oeStR P ON NAME DATE T TLE I
I * 09/20/06 DES" STATUS X55 ow CIVIL
? 1 6? DISC LEAD SITE I
Q?C• PROd. ENG. ENLARGED PLAN - DETENTION POND
S2 OUAU1Y
??aV SCALE PROJECT NUMBER DPANNL NUMBER REV I
p?P NOTED 22COl1,XX 00-C-30-99-20 A
I I
L---------------------------------------------- -------------- 6100 rx.E NP. o0-c-0o-s9-lO.oNc J
Appendix B
Calc. #1 Soils Map
Vegetative Analysis Map

tV
z
8

m? a
a
LEGEND c 2
(? U CJ

SYMOL SOIL NAM LIMITATION LIMI"G FA'*OR
S '
NOTES
LIATODAN SERIES:

}
Y STEEP
WELL 1
SOILS INFORMATION TAKEN FROM USDA SOIL
N
I
T
OF GENT
Y SLOPING TO MOOERAT m
ALTAVISTA SLIGHT NONE
A'A ,
.
.
TINE MAYODAN SERIES CO
S
S
S
L
DRAINED S LS THAT ARE DEEP W MODERATELY DEEP OVER HARO ROCK. THESE CONSERVATION SERNCE SOIL SURVEY FOR WAKE C
R
OF BOLT T
OUNTY, J
ON
SOLS ARE ON ROUNDED OPACES THAT HAVE A DIFFERENCE IN ELEVA
NORTH CAROLINA, ISSUED NOVEMBER. 1970, MAP IFS 82 AND
THEY CGLJPY LAN AR
ET BETWEEN THE REST AND LOWEST POINTS
5
F Z
®
MIE MAYODAN MODERATE SLOPES > 157 .
0
E
WHERE THEY HAVE FORMED UNDER FOREST BJ.
THE WESTERN PART OF THE CWNTY a

Mg6 MAYOJAN MODERATE COARSE FRAGMENTS .
IHE MATERIAL IN vmlOf THEY FORMED HAS WEATHERED FROM SANDSTONE.
THE WATER TABLE -ANS BELOW THE
F 0: iRIASSC ACL
'
AN
MA
L.
f
k
M982 MgrODAN MODERATE COARSE FRAGMENTS L
MUDS
ONE.
D S
I
SOLJM rr/Q^

LO =, MgC MAYOOAN MODERATE COARSE FRAGMENTS WCRSHAM SERIES:

THE WORSHAM SERIES CONSISTS OF NEARLY LEVEL AND F TLY SLOPING, DEEP, vJ N
MaC2 MAVODhN MODERATE COARSE FRAGMENTS POORLY DRAINED SOPS OF PIEDMONT UPLANDS. THESE SMS OCCUPY SMALL AREAS
DIROUDHOUT THE COUNTY. AT THE HEADS OF DRAWACEWATS. W FOOT SLOPES. AND
O

IGHT NONE
S IN SLIGHT DEPRESS- THEY HAVE FARMED UNDER FOREST W TRANSLOCATEO
WEATHERED FROM MOST KINDS OF ROCKS UNDERLYING
ATERA
AND IN MATERIA
FOR REVIEW ONLY-
_
NYC MAYODAN
L L
M
L
_S AREA. A SEASONALLY HIGH WATER TABLE IS APPRDKWATELY Al THE SURFACE. NOT FOR CONSTRUCTION
L_L M>'J MAYOOgN MODERATE SLOPES > T07.

MfD2 MAYODAN MODERATE SLOPES > TOR AETANSTA SERIES! GRAPHIC SCALE
-
l'kiLS DRAWING IS IE PROPERTY OF
k 9NFEt
THE ALTANSTA SERIES CONSSTS OF NEARLY LEVEL AND GEHRY SLOPING, DEEP.
CES THE AREAS ARE
RR I SpsldsE l NvTM, PA PA i G`-2 .0
W y SEVERE FLOODING/HIGH WATER TABLE
Y A
MODERATELY WELL DRAINED SOILS ON LOW STREAM TE
THE SDLS
T LARGE AND ARE NEAR THE MA,OR STREAMS IN THE CDJHTY
FAIR rW?
?rr?= F Fi wa
? li

- M1
.
I
I.... a
HAVE FORMED IN ALLUVIAL DEPCSITS J.131. FOREST VEGETAIW. A SEASONAL RICH _r

•
•

Rt0'CCF

AFAR
WATER TABLE IS AT A DEPTH OF APPROAIMAIEIY 2 FEET. M?A?W ??? 236-00

Ln -
ti
0 0
i J Eol CALCULATION COVER SHEET
PROJECT USFCC JOB NO. 22C01103 DEPARTMENT Civil
CLIENT Novartis Vaccines & Diagnostics CALC. NO. C-4
SUBJECT BMP Wet Detention Pond - Sediment Basin Calculations
ORIGINATOR Ed Kubrin DATE 9/06
CHECKER Tim Horstman DATE 9/06
??HUiir?hr
Q??, CARU??2%%
SS/p•
/W809584
.
I'G INS. ''k,
.
A N C E
gIZ1106
PURPOSE OF ISSUANCE
REV
NO. PAGES DESCRIPTION ORIG. DATE CHKD. DATE APRV. DATE
A 9 Issued for Permitting and
Information

COMMENTS: These calculations are in support of an application for a 401 Certification to the North Carolina
Division of Water Quality.
Calc Cover-BMP Pond Sediment Basin.DOC 02/19/96
Calculation #4
Sediment Basin Calculations

a'`s f
f ?
Project: Novartis USFCC
Location: Holly Springs, N.C.
Date: 8/31/2006
Subject: Erosion Control Sediment Basins
The following calculations for Sediment Ponds follows the "Town of Holly Springs Engineering Design
and Construction Standards", Section 4.03 F and NCDENR Erosion and Sediment Control
Planning and Design Manual.
1. Rational Method Discharge from a 10 yr storm
Values determined from "Stormwater Design Manual" Wake County.
Sed. Basin "C" "I" Area Ac "Q" Discharge (cfs)
DA1,2,3b 0.5 4.1 26.2 53.71
Note: "C" coefficient of land use use is based on "Graded Clayey Soil, 0-5%". C=0.50
"I" detemined from the 10 yr, storm event with a time duration of 25 minutes.
See attached sheets for determination of "C" , "I", and "A"
2. Minimum Storage Capacity
Sed. Basin Drainage Area Min. Vol CF/Ac Volume Reauired Volume Available
DA1,2,3b 26.2 1800 47160 147423
Volume available from elevation 308 to elevation 316.75
3. Minimum Surface Area
Surface Area Reauired
Sed. Trap "Q" Discharge (cfs) A=0.01-Q (SF) Surface Area Available
DA1,2,3b 53.71 23396 26726
Surface area available at elevation 316.75
"Q" in surface area required, is the discharge from the 10 yr storm event.
4. Principal Spillway Capacity
Sed. Trap Reqd. Capacity Capacity Available
DA1,2,3b 5.24 34.86
The "Capacity Available" is for the permanent wet detention pond (See Calculation #1).
5. Emergency Spillway Capacity
Q 10 yr
Sed. Trap Discharge (cfs) Capacity Available
DA1,2,3b 53.71 210.68
The "Capacity Available" is for the permanent wet detention pond (See Calculation #1).
I:\CIVIL\STORMWATER MANAGEMENT CALCS\Calculation #4 - Sediment Basins\SedBasin.xls
Woodlands 0.20-0.25
Parks, cemeteries 0.25
Playgrounds 0.35
Lawns:
Sandy soil, flat, 2% 0.10
Sandy soil, average, 2 - 7% 0.15
Sandy soil, steep, > 7% 0.20
Clay soil, flat, 2% 0.17
Clay soil, average, 2 - 7% 0.22
Clay soil, steep, > 7% 0.35
Graded or no plant cover
Sandy soil, flat, 0 - 5% 0.30
Sandy soil, flat, 5 - 10% 0.40
Clayey soil, flat, 0 - 5% 0.50 4
Clayey soil, average, 5 - 10% 0.60
Residential:
Single-family (R - 4) 0.50
Single-family (R - 6) 0.55
Multi-family (R - 10) 0.60
Multi-family (R - 20) 0.70
Multi-family (R - 30) 0.75
Business:
O & 1 (I, II, 111) 0.85
11 & 12 0.85-0.95
Shopping Centers 0.85-0.95
Streets:
Gravel areas 0.50
Drives, walks, and roofs 0.95
Asphalt and Concrete 0.95-1.00
It is often desirable to develop a composite runoff coefficient based on the percentage of different types of
surfaces in the drainage areas. Composites can be made with the values from Table 2.2 by using
percentages of different land uses, as illustrated in Equation 2.2. In addition, more detailed composites
can be made with coefficients for different surface types such as roofs, asphalt, and concrete streets,
drives and walks. The composite procedure can be applied to an entire drainage area or to typical
"sample" blocks as a guide to the selection of reasonable values of the coefficient for an entire area.
Composite C =
C1*A1 + C2*A2 +... Cx*Ax
Al+A2+...Ax
(2.2)
2.2.3 Rainfall intensity
The rainfall intensity (1) is the average rainfall rate in in./hr for a duration equal to the time of concentration
for a selected return period. Once a particular return period has been selected for design and a time of
concentration calculated for the drainage area, the rainfall intensity can be determined from the intensity-
duration-frequency (IDF) data for the City of Raleigh given in Table 2.3.
rr-? S?a?`/'2a.JA?er ?GS?4n 'liLnda r
I'i'O?'1 : cJJ

To
p
a?
z
IOW
F-
-"^'- 1 ?yl
Figure 2.1
Rational Formula - Overland Time of Flow Nomograph

Z?M ??.?S T, ?a .1-
Table 2.3. Intensity - Duration - Frequency Table
City of Raleigh North Carolina
Fre uenc rs
Duration 2 5 10 25 50 100
5 min 5.76 6.58 7.22 8.19 8.96 9.72
10 4.76 5.54 6.13 7.01 7.71 8.40
15 4.04.- 4.74 5.25 6.03 6.64 7.24
20 3.47 4.12 5.42 5.93 6.47
30 2.70 3.28 3.71 4.32 4.80 5.28
40 2.28 2.77 3.70 4.08 4.48
50 1.94 2.38 2.71 3.19 3.53 3.88
60 1.70 2.12 2.41 2.84 3.17 3.50
90 1.22 1.52 1.74 2.06 2.29 2.53
2 hr 0.95 1.20 1.37 1.62 1.81 2.00
3 0.71 0.89 1.02 1.21 1.35 1.50
6 0.44 0.56 0.65 0.77 0.86 0.96
12 0.26 0.33 0.39 0.46 0.52 0.57
24 0.15 0.19 0.22 0.27 0.30 0.33Lil
JA Ito", 3.6 4.5(9 5.2a (.48 -I -2 ?.atI-
(Developed by Dr. H.R. Malcom, North Carolina State University, Dept. of Civil Engineering, and the
authors based on NOAA HYDRO-35 and USWB TP-40)
2.2.4 Time Of Concentration
Use of the rational formula requires the time of concentration (tc) for each design point within the
drainage basin. The duration of rainfall is then set equal to the time of concentration and is used to
estimate the design average rainfall intensity (1). The time of concentration consists of an overland flow
time to the point where the runoff enters a defined drainage feature (i.e., open channel) plus the time of
flow in a closed conduit or open channel to the design point.
There are several acceptable methods for calculating the time of concentration, including a simple
nomograph for use with the rational formula or the use of routing equations such as the kinematic wave or
Kirpich equations.
2.2.4.1 Simple Nomograph
Figure 2.1 is a simple nomograph that can be used to estimate overland flow time. For each drainage
area, the distance is determined from the inlet to the most remote point in the tributary area. From a
topographic map, the average slope is determined for the same distance. The runoff coefficient (C) is
determined by the procedure described in a subsequent section of this chapter.
To obtain the total time of concentration, the pipe or open channel flow time must be calculated and
added to the inlet time. After first determining the average flow velocity in the pipe or channel, the travel
time is obtained by dividing velocity into the pipe or channel length. Velocity can be estimated by using
the nomograph shown on Figure 2.2. Note: time of concentration cannot be less than 5 minutes.
2.2.4.2 Kinematic Wave
Another method that can be used to determine the overland flow portion of the time of concentration is
the "Kinematic Wave Nomograph - Figure 2.3." The kinematic wave method incorporates several
variables including rainfall intensity and Manning "n". In using the nomograph, the engineer has two
unknowns starting the computations, the time of concentration and the rainfall intensity. The problem is
attempting to determine a rainfall intensity, which in turn actually determines the time of concentration.
Thus, the problem is one of iteration. A value of "I" must be assumed, compute a time of concentration
and then check back to see if the rainfall intensity that was assumed is consistent with the rainfall

IN-
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3 -? - ;
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l /
?
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uv Dve .nso< oaa s?a .ae«mrn m a?.vo. ocsoan. .r..orto m.?w .o. artz«a wwcs Z r.e drt nnF?
// rssum <m AT.,e. X45 STORMWATER MANAGEMENT
? POST DEVELOPMENT PUN
?
Q
out
2V S41L wq¢'r F1?EA DA.wC xu4w AN
? '

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22CO -XX
fl
00-C-40-99-12
A

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HOLLY SPRINGS N.C.
PN 22COl 16S CAMPUS A POND "BORROW AREA" CALCULATIONS 8/30/2006
Sediment Basin Storacie
BO RROW END AREA
ELEVATION AREA DIST AVG. AREA sf) VOLUME (c
308 4082
3 14034.5 42104
311 9081
3 22857 68571
314 18988
1 10881.5 10882
315 21763
2.75 13363 36748
316.75 26726

S wzrAcii A

V®WM A\IAILAB !.6

TOTALS 61136 158304
AC-FT

NOTES

I-

Type.... Composite Rating Curve
Name.... Outlet DA123b
Page 1.06
6/'-?'?eftl:? 111
Title... Project Date: 7/20/2006
Project Engineer: Ed Kubrin
Project Title: Aardvark Holly Springs
Project Comments:
Post developed conditions and discharge for 2, 10,
and 100 yr storm events in drainage area DA2a,
DA123B, and DA3a.
DA2a is less in area than DA2 (predeveloped). DA3a is
less in area than DA3 (predeveloped). Areas from DA1,
2, & 3 (predeveloped) create DA1,2,3b in the post
developed conditions. This DA 1,2,3b area is routed
through the pond.
Target outflow volumes are determined from the
outfall point OUTDA123. Predeveloped peak discharges
from the 1,2,&100 yr strom events are used for the
allowable target discharge rate.
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
-------- -------- ----- --- Converge - ---- ---- ---- --------
Elev. Q TW E lev Error
ft
-------- cfs
------- f
----- t +/-ft
--- ----- Contr
------ ibut
---- ing
---- Structures
--
-

318.60
4.39
Free
Outfall
00 -
--------
318.70 4.55 Free Outfall 00
318.80 4.71 Free Outfall 00
318.90 4.86 Free Outfall 00
319.00 5.00 Free Outfall 00
319.10 5.14 Free Outfall 00
319.20 5.28 Free Outfall R1 +R2 +RO +00
319.30
319.40 6.68
9.12 Free
Free Outfall
Outfall R1
R1 +R2
+R2 +RO
+RO +00
+00 p
4------'L 2 1 fZ?:?L
-319.50 12.24 Free Outfall R1 +R2 +RO +00
319.60 15.90 Free Outfall R1 +R2 +RO +00
319.70 20.04 Free Outfall R1 +R2 +RO +00
319.80 24.61 Free Outfall Rl +R2, +RO +00
319.90 Z2,516- Free Outfall R1 +R2 +RO +00 p
O
"L??
320,OQ 3 ,Fre, Outfall R1 +R2 +RO +Q
Q t
4 16Y?2IEF,,G?V -
,

a=9 Z CAS
a-
Q:. 41.9 cis 0-
S/N: 68YXYWGYMXBD Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 12:48 PIM 8/31/2006
ut/'
Wet Detention Pond Emergency Spillw
a y
Prallect'Descr ption
Friction Method Manning Formula
Solve For Discharge
IrTOUt Data
Roughness Coefficient 0.030
Channel Slope 0.07000 ft/ft
Normal Depth 1.00 ft
Left Side Slope 3.00 ft/ft (H:V)
Right Side Slope 3.00 ft/ft (H:V)
Bottom Width 15.00 ft
(?@SUItS I
Discharge
21
?

Flow Area 0.68
ft /s G /tP sal I i
AUK !?
18.00 ft:
Wetted Perimeter 21.32 ft
Top Width 21.00 ft
Critical Depth 1.63 ft
Critical Slope 0.01233 ft/ft
Velocity 11.70 ft/s
Velocity Head 2.13 ft
Specific Energy 3.13 ft
Froude Number 2.23
Flow Type Supercritical
jn?sllt -bata
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
C?WFT`??Itj?utData'.
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity f{/s
Normal Depth 1.00 ft
Critical Depth 1.63 ft
Channel Slope 0.07000 ft/ft
Critical Slope 0.01233 ft/ft
Bentley Systems, Inc. Haestad Methods Solution Center
9121/2006 10:48:52 AM 27 Slemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755---11666 Page FlowMas [08.01.066.0
Page 1 of I
I-
CALCULATION COVER SHEET
PROJECT USFCC JOB NO. 22C01103 DEPARTMENT Civil
CLIENT Novartis Vaccines & Diagnostics CALC. NO. C-7
SUBJECT BMP Wet Detention Pond - Outlet Protection Calculations
ORIGINATOR Tim Horstman DATE 9/06
CHECKER Mark Smith DATE 9/06
CAR`S,!?f"
1??0 ; ??SS/p• 9
E ZP1
8984
11q NCE
1'11111%
/ ?, -? le, (,
N
PURPOSE OF ISSUANCE
REV
NO. PAGES DESCRIPTION ORIG. DATE CHKD. DATE APRV. DATE
.A 7 Issued for Permitting and
Information

COMMENTS: These calculations are in support of an application for a 401 Certification to the North Carolina
Division of Water Quality.
Calc Cover-BMP Pond Outlet Protection.DOC 02/19/96
Calculation #7
Outlet Protection Calculations

OUTLET PROTECTION CALCULATIONS
The methodology used to design the outlet protection features is based on the "Erosion
and Sediment Control Planning and Design Manual" dated June 1, 2006 by a cooperative
effort between the North Carolina Sedimentation Control Commission, the North
Carolina Department of Environment and Natural Resources, and the North Carolina
Agricultural Extension Service. Specifically, Chapter 6.41 addresses the design of outlet
protection as well as 8.06.1.
The culvert pipe diameters (Do) and associated flows (Q) at each outlet was determined
using StormCAD software. Discharge Q is from the 10 year stone event. See
calculation #1 for outlet 5 and calculation #2 for outlets 1 to 4.
Given the pipe diameter and the flow, Figure 8.06a is used to determine the average size
riprap (dso) as well as the length of the riprap apron (La). - See attached copies of Figure
8.06a for each case.
The apron width-at the outlet pipe as well as at the end of the apron is determined using
Figure 8.06a.
me The maximum stone diameter (dmx) is = 1,5d5o
The apron thickness ( 1.5 x dmax) can be determined;
RESULTS:
Outlet Pipe Apron Average Apron Apron maximu Apron
Number dia. length stone width at width at m stone thickness
(Da) (L8) size outlet end of diameter (1.5 x d,tj
(d50) pipe Apron (dn,Bx) _
=3xDo =La+D,, .1.5d5o
1 24" 18' 6' 20' 11" 17„
2 and 3 12" 8' 4" 3' 9' 6" 9"
4 42" 23' 10" 10.5' 26.5' 15" 23"
5 30" 18' 7" 7.5' 9' 11 " 17
mw I
29 CFS
1 ~\?\. PRapO5E0 GRCE?I ?'Kg... _. _ l \i j ?- ?.- l c \\ 24" DIAMETER PIPE I
U-
l-
\ 1
?1 1 / '4 J Q = 94 CFS
1 11 \ _ \ ® 42" DIAMETER PIPE t?
PONDOUI'LET
42 Cf:??
30" DLINIETER PIPL-
.sail R ? ? \ ,} .? :•?O `\ '?? ?'S r
B
\ Q ° 6.6 CFS
\ 12" DIAMETER PIPE ;'?? • . ?"
\ LJ uv ?
I P \\
\ Q = 6.5 CFS r. RIPRAP MAP
I \\ 12" DIAMETER PIPE
?1 r 1
RR?
'v
Be
,29 cf5
Curves may not be extrapolated.
? =,Z 9 cis
RIPRAP 0
in
1
L
1

Design of Riprap Apron under Minimum Tailwater Conditions
(Source: USDA, SCS, 1975)
i.
30? ---TT
8
w
Curves may not be extrapolated.
I ) //
RIPRAP ?Z a10 ?j
Ile
Design of Riprap Apron under Minimum Tailwater Conditions
(Source: USDA, SCS, 1975)

w
3 0
Outlet IW - Do + la
diameter (Do)
pipe 1
La
i water < 0.500 ?I
?onl? l?t?l
a U
060 \110e
10
0
3 5
a P
??. -.:?. .•,. V-20
15• s .I
10 20 50 00 ?+ 200
Discharge (0/sec) 94 Cry
4
3
2 to
1
'
10
;:1- 1:1 1:111r1111 I0
500 1000
Curves may not be extrapolated.
Q = 9f cis
"'1?2 0 PIPE
Design of Riprap Apron under Minimum Tailwater Conditions
(Source: USDA, SCS, 1975)
30- i'1T
I?

Curves may not be extrapolated.
Q = `{Z c&
30', 0 'P
RIPRAP SO

N_ -
CL
ro
n
Q
0
-o
7/,
Design of Riprap Apron under Minimum Tailwater Conditions
(Source: USDA, SCS, 1975)