20090105 Ver 1_More Info Received_20090224

Soil & Environmental Consultants, PA
11010 Raven Ridge Road • Raleigh, North Carolina 27614 • Phone: [phone] • Fax: [phone]
www.SandEC.com
February 24, 2009
S&EC Project # 5786.W2
DWQ EXP Project #09-0105
NC Department of Environment and Natural Resources
Division of Water Quality
401 Oversight/Express Review Permitting Unit M ll
Attn: Cyndi Karoly/Lia Gilleski 174
2321 Crabtree Boulevard, Suite 250 FED 2 4 2009
Raleigh, NC 27604
y ? DENR - WATER QUALITY
Re: Reply to the Division of Water Quality's Request for More Informati LANDS AND STORMWATER BRANCH
Searstone
Wake County, NC
To Mrs. Karoly and Mrs. Gilleski:
The purpose of this letter is to provide the additional information requested at our site visit
dated February 20, 2009. During our site visit it was determined that the level spreaders were
not designed appropriately as they pertain to the existing vegetation, therefore all four (4) level
spreader have been redesigned. Included with this submittal are revised supplemental forms,
preliminary stormwater management calculations, a HY-8 Energy Dissipation Report, worksheet
for Circular Channel, Water Quality Volume Design Sheets and updated constructions plans.
Additionally, Mr. James Caldwell has provided a response that is attached for your review.
We anticipate that this answers all of the DWQ's questions in order to complete the final review
process requested for the written concurrence of a Riparian Buffer Authorization. If you have
any further questions or any additional explanation is needed, please don't hesitate to call.
Sincerely,
Qjj? C1? ?-
Debbie Edwards
Environmental Specialist
CC: u
William Sears-Sears Farm, LLC
Andy Padiak-The John R. McAdams Company, Inc.
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Attachments:
1) Searstone Response letter from Mr. James W. Caldwell of the John R. McAdams
Company, Inc. and attachments
2) Construction Drawings (SW-1A, SW-1C, SW-2A, SW-3A and SW-4A)
Charlotte Office: Greensboro Office:
236 LePhillip Court, Suite C 3817-E Lawndale Drive
Concord, NC 28025 Greensboro, NC 27455
Phone: [phone] Phone: [phone]
Fax: [phone] Fax: [phone]
Since 1979
THE JOHN R. McADAMS COMPANY, INC.
Research Triangle Park, NC
Post Office Box 14005
Research Triangle Park,.
North Carolina 27709
2905 Meridian Parkway
Durham, North Carolina 27713
800-733-5646
919-361-5000
919-361-2269 Fax
Charlotte, NC
5311 Seventy-Seven Center Drive
Suite 66
Charlotte, North Carolina 28217
800-733-5646
704-527-0800
704-527-2003 Fax
Wilmington, NC
3904 Oleander Drive
Suite 200
Wilmington, North Carolina 28403
800-733-5646
910-799-8181
910-799-8171 Fax
February 23, 2009
Ms. Debbie Edwards
Soil & Environmental Consultants, PA
11010 Raven Ridge Road
j Raleigh, North Carolina 27614
Re: . Searstone
2nd Request for More Information
DWQ EXP No. 09-0105
SRF-05000
Dear Ms. Edwards:
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Please find attached revised plans and calculations based on our on-site meeting
with representatives from The NC Division of Water Quality on February 20,
2009. The following changes have been made to the plans and calculations:
1) A representative level spreader filter strip calculations has been performed
for the outfall areas of the 4 stormwater management facilities. This
calculation is for the "dense ground cover" and "wooded" areas for the
outfalls of the level spreaders. This calculations considers the open area
between the level spreader and the Town of Cary buffer, the 50' "wooded"
Town of Cary buffer, and the "wooded" and "open" areas within the Neuse
River Buffer and sewer easement. This representative outfall results in 65%
"dense ground cover" and 35% "wooded". Using the DWQ weighted cover
equation, this results in 31 feet per cfs for the level spreader length. Each of
the 4 level spreaders have been changed per this ratio.
2) For Pond #1, the outlet structure was changed to lower the 1" outflow to
result in a level spreader shorter than the 130' limit. The new outflow from
Pond #1 is 3.78 cfs as shown in the attached PondPack output. The resulting
level spreader is 118' as shown on the revised Sheet SW-1A. Pond #1 still
retains the previous detention function and passes the larger design storms
with adequate freeboard.
3) The Supplement Forms have been revised for the 4 stormwater management
facilities.
www.johnrmcadams.com i Design Services Focused On Client Success
S't -e
THE JOHN R. McADAMS COMPANY, INC.
Ms. Debbie Edwards
Searstone Response to Comments
February 23, 2009
Page Two
Please call me at [phone] should you have any questions or need any
additional information.
Sincerely,
THE JOHN R. McADAMS COMPANY, INC.
James W. Caldwell, PE
Project Manager
cc: Mr. William Sears, Sears Farm, LLC
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
I. PPOJEC -t"FC ATION
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008
Drainage area number To Pond #1

For Level Spreaders Receiving Flow From a BMP
Type of BMP Wet Pond
Drawdown flow from the BMP 3.78 cfs
For Level Spreaders Receiving Flow from the Drainage Area Do not complete this section of the worksheet.
Drainage area N/A ftZ Do not complete this section of the worksheet.
Impervious surface area N/A ft2 Do not complete this section of the worksheet.
Percent impervious #VALUE! % Do not complete this section of the worksheet.
Rational C coefficient N/A Do not complete this section of the worksheet.
Peak flow from the 1 in/hr storm #VALUE! cfs Do not complete this section of the worksheet.
Time of concentration ., N/A min
Rainfall intensity, 1 0-yr storm NIA in/hr Do not complete this section of the worksheet.
Peak flow from the 10-yr storm #VALUE! cfs Do not compiete this section of the worksheet.
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a filter strip or riparian buffer? Y (Y or N) Please complete filter strip characterization below.
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?
ft
80.00 ft
43.00 ft
123.00 ft
336.75 fmsl
330.00 fmsl
5.49 % OK
N (Y or N) OK
N/A sq ft No forebay is needed.
31 ft/cfs
N (Y or N)
N (Y or N)
Y (Y or N)
3.78 cfs
Y (Y or N) OK
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 1 of 2
Length of the level lip 118.00 ft
Are level spreaders in series? N (Y or N)
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland? N (Y or N)
Does the channel enter the stream at an angle? Y (Y or N)
Dimensions of the channel (see diagram below):
M N/A ft
B N/A ft
W N/A ft
y N/A ft
Peak velocity in the channel during the 10-yr storm 27.20 fps cfs
Channel lining material 42' dia. o-ring pipe
N
1
I 1
t 1

M
M

1 B 1
#VALUE!
1
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 2 of 2
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
L PROJECT lyFOT IIATION
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008
Drainage area number To Dry Detention Basin #2
fl. D r ,,
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin
Drawdown flow from the BMP 0.92 cfs
For Level Spreaders Receiving Flow from the Drainage Area Do not complete this section of the worksheet.
Drainage area ft2 Do not complete this section of the worksheet.
Impervious surface area ft2 Do not complete this section of the worksheet.
Percent impervious % Do not complete this section of the worksheet.
Rational C coefficient Do not complete this section of the worksheet.
Peak flow from the 1 in/hr storm cfs Do not complete this section of the worksheet.
Time of concentration min
Rainfall intensity, 10-yr storm in/hr Do not complete this section of the worksheet.
Peak flow from the 10-yr storm cfs Do not complete this section of the worksheet.
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a filter strip or riparian buffer? Y (Y or N) Please complete filter strip characterization below.
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass 0.00 ft
Width of dense ground cover 101.00 ft
Width of wooded vegetation 54,00 ft
Total width 155.00 ft
Elevation at downslope base of level lip 335.50 fmsl
Elevation at top of bank of the receiving water 330.00 fmsl
Slope (from level lip to to top of bank) 3.55 % OK
Are any draws present? N (Y or N) OK
Level Spreader Design
Forebay surface area N/A sq ft No forebay is needed.
Feet of level lip needed per cfs 31 ft/cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm? N (Y or N)
Length based on the 10-yr storm? N (Y or N)
Length based on the BMP discharge rate? Y (Y or N)
Design flow 0.92 cfs
Is a bypass device provided? Y (Y or N) OK
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 1 of 2
Length of the level lip 29.00 ft
Are level spreaders in series? N (Y or N)
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland? N (Y or N)
Does the channel enter the stream at an angle? Y (Y or N)
Dimensions of the channel (see diagram below):
M N/A ft
B N/A ft
W N/A ft
y N/A ft
Peak velocity in the channel during the 10-yr storm 4.47 fps cfs
Channel lining material 36" dia. o-ring pipe
#VALUE!
?
W ?
i
7"" • r,
---------
M

1 B 1
i
1
M
Form SW401-Level Spreader, Filler Strip, Restored Riparian Buffer-Rev.5 Parts I. and It. Design Summary, page 2 of 2
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
L PR0,1 .. :-f ON.11A?)f1
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date
Drainage area number
October 22, 2008
To Dry Detention Basin #3
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin
Drawdown flow from the BMP 1.32 cfs
For Level Spreaders Receiving Flow from the Drainage Area Do not complete this section of the worksheet.
Drainage area ftz Do not complete this section of the worksheet.
Impervious surface area ff2 Do not complete this section of the worksheet.
Percent impervious % Do not complete this section of the worksheet.
Rational C coefficient Do not complete this section of the worksheet.
Peak flow from the 1 in/hr storm cfs Do not complete this section of the worksheet.
Time of concentration min
Rainfall intensity, 10-yr storm in/hr Do not complete this section of the worksheet.
Peak flow from the 10-yr storm cfs Do not complete this section of the worksheet.
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a fifter strip or riparian buffer? Y (Y or N) Please complete filter strip characterization below.
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass 0.00 ft
Width of dense ground cover 74,00 ft
Width of wooded vegetation 38,00 ft
Total width 112,00 ft
Elevation at downslope base of level lip 323.50 fmsl
Elevation at top of bank of the receiving water 320.00 fmsl
Slope (from level lip to to top of bank) 3.13 % OK
Are any draws present? N (Y or N) OK
Level Spreader Design
Forebay surface area N/A sq ft No forebay is needed.
Feet of level lip needed per cfs 31 ft/cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm? N (Y or N)
Length based on the 10-yr storm? N (Y or N)
Length based on the BMP discharge rate? Y (Y or N)
Design flow 1.32 cfs
Is a bypass device provided? Y (Y or N) OK
Form SW401-Level Spreader, Fifter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 1 of 2
Length -of the level lip
Are level spreaders in series?
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Dimensions of the channel (see diagram below):
M
B
W
y
Peak velocity in the channel during the 10-yr storm
Channel lining material

M
41.00 ft
N (Y or N)
N (Y or N)
Y (Y or N)
N/A ft
N/A ft
N/A ft
N/A ft
8.82 fps cfs
36" dia. o-ring pipe
1 B 1
1
M
#VALUE!

Form SW401-Level Spreader, Fifter Strip, Restored Riparian-Buffer-Rev.5 Parts I. and II. Design Summary, page 2 of 2
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)I
I. PR JECT;1 FORMATION
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008
Drainage area number To Dry Detention Basin #4
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin
Drawdown flow from the BMP 1.14 cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area
Impervious surface area
Percent impervious
Rational C coefficient
Peak flow from the 1 in/hr storm
Time of concentration
Rainfall intensity, 10-yr storm
Peak flow from the 10-yr storm
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell?
To a mulched bioretention cell?
To a wetland?
To a filter strip or riparian buffer?
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cfs
Answer "Y" to one of the following:
Length based on the 1 in/hr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?
ft2 Do not complete this section of the worksheet.
ft2 Do not complete this section of the worksheet.
% Do not complete this section of the worksheet.
Do not complete this section of the worksheet.
cfs Do not complete this section of the worksheet.
min
in/hr Do not complete this section of the worksheet.
cfs Do not complete this section of the worksheet.
N (Y or N)
N (Y or N)
N (Y or N)
Y (Y or N) Please complete filter strip characterization below.
0.00 ft
81.00 ft
43.00 ft
124.00 ft
319.50 fmsl
316.00 fmsl
2.82 % OK
N (Y or N) OK
N/A sq ft No forebay is needed.
31 ft/cfs
N (Y or N)
N (Y or N)
Y (Y or N)
1.14 cfs
Y (Y or N) OK
Do not complete this section of the worksheet
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts I. and ll. Design Summary, page 1 of 2
Length of the level lip 36.00 ft #VALUE!
Are level spreaders in series? N (Y or N)
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland? N (Y or N)
Does the channel enter the stream at an angle? Y (Y or N)
Dimensions of the channel (see diagram below):
M N/A ft
B N/A ft
W N/A ft
y N/A ft
Peak velocity in the channel during the 10-yr storm 5.68 fps cfs
Channel lining material 36" dia. o-ring pipe
f W
i

t t
---------- __________?
M M

1 B l
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts 1. and II. Design Summary, page 2 of 2
SEARSTONE PRELIMINARY STORMWATER MANAGEMENT CALCULATIONS
SRF-05000 Summary of Result - Phase 1
SUB-BASIN 1
Event Pre-Development fcfsl Post-Development fcfsl Chanae fcfsl
1-Year 88 77 -12%
10-Year 240 224 -7%
50-Year 365 359 -2%
SUB-BASIN 2
Event Pre-Development fcfsl Post-Develonment fcfsl Chanae fcfsl
1-Year 4 2 -52%
10-Year 13 5 -58%
50-Year 20 8 -60%
SUB-BASIN 3
Event Pre-Development fcfsl Post-Development fcfsl Chanae fcfsl
1-Year 6 3 -50%
10-Year 15 7 -55%
50-Year 23 10 -57%
SUB-BASIN 4
Event Pre-Development fcfsl Post-Development fcfsl Chanae fcfsl
1-Year 2 1 -50%
10-Year 6 3 -51%
50-Year 8 4 -51%
Pond 1 (Upper)
Normal Pool Elevation [ft] 370.00
To of Dam ft = 372.00
100-Year WSE [ft] 370.19
100-Year Freeboard [ft] = 1.81
Pond 1 (Lower)
Normal Pool Elevation [ft] 361.00
To of Dam [ft] 365.50
100-Year WSE [ft] 364.96
100-Year Freeboard [ft] = 0.54
Dry Detention Basin 2
Bottom Elevation [ft] 336.00
To of Dam [ft] 342.00
100-Year WSE [ft] 341.83
100-Year Freeboard [ft] = 0.17
Dry Detention Basin 3
Bottom Elevation [ft] 324.00
Top of Dam [ft] 332.00
100-Year WSE [ft] 331.37
100-Year Freeboard [ft] = 0.63
Dry Detention Basin 4
Bottom Elevation [ft] = 320.00
Top of Dam [ft] 326.00
100-Year WSE [ft] 325.34
100-Year Freeboard [ft] = 0.66
* Note: All detention facilities are in Subbasin 1. There is no detention in Subbasins 2, 3, or 4
J.C. Diaz, El
2/23/2009
SOR_Master SOR
Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
MASTER DESIGN STORM SUMMARY
Network Storm Collection: RDU Rainfall
Total
Depth
Return Event in
100-Yr 8.0000
10-Yr 5.3800
1-yr 3.0000
1 inch 1.0000
50-yr 7.2100
Rainfall
Type
----------------
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
Synthetic Curve
RNF ID
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
TypeII 24hr
---------------------------
ICPM CALCULATION TOLERANCES
Target Convergence= .000 cfs +/-
Max. Iterations = 35 loops
ICPM Time Step = 1.00 min
Output Time Step = 1.00 min
ICPM Ending Time =
-------------------- 1440.00
--------- min
--
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
---------- min cfs ft ac-ft.

BYPASS
AREA
100 --
5.742 ---------
727.00 --------
68.16 -------- --------.----
BYPASS AREA 10 3.294 727.00 39.64
BYPASS AREA 1 1.276 727.00 15.12
BYPASS AREA 0 .085 733.00 .44
BYPASS AREA 50 4.991 727.00 59.52
POND #1-LOWER POND 100 13.664 715.00 203.03
POND #1-LOWER POND 10 8.905 715.00 134.62
POND #1-LOWER POND 1 4.612 715.00 71.65
POND #1-LOWER POND 0 1.138 716.00 17.74
POND #1-LOWER POND 50 12.227 715.00 182.46
POND #1-LOWEROUT POND 100 13.383 722.00 137.83 364.96 1.739
POND #1-LOWEROUT POND 10 8.691 718.00 115.28 363.50 1.097
POND #1-LOWEROUT POND 1 4.468 720.00 58.90 362.92 .842
POND #1-LOWEROUT POND 0 1.070 732.00 3.78 361.98 .428
POND #1-LOWEROUT POND 50 11.965 722.00 132.85 364.38 1.485
POND #1-UPPER POND 100 2.051 715.00 32.22
POND #1-UPPER POND 10 1.380 715.00 21.67
POND #1-UPPER POND 1 .769 715.00 12.08
POND #1-UPPER POND 0 .256 715.00 4.03
POND #1-UPPER POND 50 1.849 715.00 29.04
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 9:51 AM Date: 2/23/2009
Type.... Master Network Summary Page 2.02
Name.... Watershed,
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
-------------------------------
ICPM CALCULATION TOLERANCES
-------------------------------
Target Convergence= .000 cfs +/-
Max. Iterations = 35 loops
ICPM Time Step = 1.00 min
Output Time Step = 1.00 min
ICPM Ending Time = 1440.00 min
-------------------------------
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 Stcrage
Node
-
- ID
- Type Event ac-ft Trun min cfs ft ac-ft
--
-
POND -
------
#1-UPPE ----
ROUT ----
POND ------
100 ---------- --
2.037 ---------
724.00 --------
11.94 --------
370.19 ------------
.588
POND #1-UPPE ROUT POND 10 1.371 724.00 8.04 370.13 .396
POND #1-UPPE ROUT POND 1 .765 724.00 4.49 370.07 .221
POND #1-UPPE ROUT POND 0 .254 724.00 1.50 370.02 .074
POND #1-UPPE ROUT POND 50 1.835 724.00 10.77 370.17 .530
POND #2-PH2 IN POND 100 10.822 715.00 190.62
POND #2-PH2 IN POND 10 6.695 715.00 121.19
POND #2-PH2 IN POND 1 3.075 715.00 57.46
POND #2-PH2 IN POND 0 .461 716.00 8.17
POND #2-PH2 IN POND 50 9.570 715.00 169.79
POND #2-PH2 OUT POND 100 9.962 724.00 71.51 341.83 5.292
POND #2-PH2 OUT POND 10 6.077 760.00 8.07 340.67 4.003
POND #2-PH2 OUT POND 1 2.941 800.00 2.39 338.51 1.834
POND #2-PH2 OUT POND 0 .445 820.00 .41 336.48 .228
POND #2-PH2 OUT POND 50 8.777 725.00 57.33 341.46 4.881
POND #3 IN POND 100 9.157 715.00 162.47
POND #3 IN POND 10 5.620 715.00 102.43
POND #3 IN POND 1 2.535 715.00 47.53
POND #3 IN POND 0 .353 716.00 6.10
POND #3 IN POND 50 8.083 715.00 144.45
POND #3 OUT POND 100 9.109 723.00 84.69 331.37 3.219
POND #3 OUT POND 10 5.597 722.00 66.72 329.59 2.246
POND #3 OUT POND 1 2.529 776.00 2.87 327.79 1.359
POND #3 OUT POND 0 .352 752.00 .58 324.64 .135
POND #3 OUT POND 50 8.044 723.00 80.08 330.80 2.898
POND 44 IN POND 100 3.318 715.00 58.01
POND #4 IN POND 10 2.069 715.00 37.18
POND #4 IN POND 1 .967 715.00 18.00
POND #4 IN POND 0 .156 716.00 2.83
POND #4 IN POND 50 2.939 715.00 51.76
POND #4 OUT POND 100 3.317 719.00 47.25 325.34 1.041
POND #4 OUT POND 10 2.068 725.00 12.72 324.80 .902
POND #4 OUT POND 1 .967 735.00 2.35 322.76 .434
POND #4 OUT POND 0 .156 729.00 .53 320.58 .054
POND #4 OUT POND 50 2.939 721.00 38.96 325.23 1.012
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 9:51 AM Date: 2/23/2009
Type.... Master Network Summary Page 2.03
Name.... Watershed
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTE;R.PPW
-------------------------------
ICPM CALCULATION TOLERANCES
-------------------------------
Target Convergence= .000 cfs +/-
Max. Iterations = 35 loops
ICPM Time Step = 1.00 min
Output Time Step = 1.00 min
ICPM Ending Time = 1440.00 min
-------------------------------
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak
Node ID Type Event ac-ft Trun min
---------
*SUBBASIN ------
#1 -- ----
JCT ------
100 ---------- --
41.516 ---------
722.00
*SUBBASIN #1 JCT 10 25.729 722.00
*SUBBASIN #1 JCT 1 12.181 721.00
*SUBBASIN #1 JCT 0 2.107 734.00
*SUBBASIN #1 JCT 50 36.717 723.00
*SUBBASIN #2 JCT 100
*SUBBASIN #2 JCT 10
*SUBBASIN #2 JCT 1
*SUBBASIN #2 JCT 0
*SUBBASIN #2 JCT 50
*SUBBASIN #3 JCT
*SUBBASIN #3 JCT
*SUBBASIN #3 JCT
*SUBBASIN #3 JCT
*SUBBASIN #3 JCT
*SUBBASIN #4 JCT
*SUBBASIN #4 JCT
*SUBBASIN #4 JCT
*SUBBASIN #4 JCT
*SUBBASIN #4 JCT
TO POND #1-LOWER AREA
TO POND #1-LOWER AREA
TO POND #1-LOWER AREA
TO POND #1-LOWER AREA
TO POND #1-LOWER AREA
TO POND #2-PH2 AREA
TO POND #2-PH2 AREA
TO POND #2-PH2 AREA
TO POND #2-PH2 AREA
TO POND #2-PH2 AREA
TO POND #3 AREA
TO POND #3 AREA
TO POND #3 AREA
TO POND #3 AREA
TO POND #3 AREA
100
10
1
0
50
100
10
1
0
50
100
10
1
0
50
100
10
1
0
50
100
10
1
0
50
.493
.285
.113
.008
.429
.630
.368
.148
.012
.550
.249
.144
.057
.004
.217
11.639
7.542
3.852
.886
10.402
10.822
6.695
3.075
.461
9.570
9.157
5.620
2.535
.353
8.083
715.00
715.00
716.00
721.00
715.00
715.00
715.00
715.00
721.00
715.00
715.00
715.00
716.00
721.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
715.00
716.00
715.00
715.00
715.00
715.00
716.00
715.00
Max
Qpeak Max WSEL Pond Storage
cfs ft ac-ft
-------- -------- -------------
400.06
223.92
77.40
5.63
359.10
9.06
5.34
2.11
.11
7.94
11.53
6.87
2.77
.17
10.13
4.57
2.70
1.06
.06
4.01
194.58
128.94
68.48
16.66
174.85
190.62
121.19
57.46
8.17
169.79
162.47
102.43
47.53
6.10
144.45
S/N: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 9:51 AM Date: 2/23/2009
Type.... Master Network Summary Page 2.04
Name.... Watershed
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
-------------------------------
ICPM CALCULATION TOLERANCES
-------------------------------
Target Convergence= .000 cfs +/-
Max. Iterations = 35 loops
ICPM Time Step = 1.00 min
Output Time Step = 1.00 min
ICPM Ending Time = 1440.00 min
-------------------------------
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

TO
POND #4 --
AREA ------
100 ----------
3.318
TO POND #4 AREA 10 2.069
TO POND #4 AREA 1 .967
TO POND #4 AREA 0 .156
TO POND #4 AREA 50 2.939
TO SUBBASIN #2 AREA 100 .493
TO SUBBASIN #2 AREA 10 .285
TO SUBBASIN #2 AREA 1 .113
TO SUBBASIN #2 AREA 0 .008
TO SUBBASIN #2 AREA 50 .429
TO SUBBASIN #3 AREA 100 .630
TO SUBBASIN #3 AREA 10 .368
TO SUBBASIN #3 AREA 1 .148
TO SUBBASIN #3 AREA 0 .012
TO SUBBASIN #3 AREA 50 .550
TO SUBBASIN #4 AREA 100 .249
TO SUBBASIN #4 AREA 10 .144
TO SUBBASIN #4 AREA 1 .057
TO SUBBASIN #4 AREA 0 .004
TO SUBBASIN #4 AREA 50 .217
TO UPPER POND #1 AREA 100 2.053
TO UPPER POND #1 AREA 10 1.381
TO UPPER POND #1 AREA 1 .770
TO UPPER POND #1 AREA 0 .257
TO UPPER POND #1 AREA 50 1.851
Max
Qpeak Qpeak Max WSEL Pond Storage
min cfs ft ac-ft
---------
715.00 -------- -------- ------------
58.01
715.00 37.18
715.00 18.00
716.00 2.83
715.00 51.76
715.00 9.06
715.00 5.34
716.00 2.11
721.00 .11
715.00 7.94
715.00 11.53
715.00 6.87
715.00 2.77
721.00 .17
715.00 10.13
715.00 4.57
715.00 2.70
716.00 1.06
721.00 .06
715.00 4.01
715.00 32.22
715.00 21.67
715.00 12.08
715.00 4.03
715.00 29.04
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 9:51 AM Date: 2/23/2009
Type.... Outlet Input Data Page 1.01
Name.... Pond #1-Lower
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, EI
Project Title: Searstone
Project Comments:
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 361.00 ft
Increment = .20 ft
Max. Elev.= 365.50 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Stand Pipe RI ---> B1 362.000 365.500
Weir-Rectangular WE ---> B1 361.000 365.500
Culvert-Circular B1 ---> B2 354.500 365.500
Culvert-Circular B2 ---> TW 339.600 365.500
TW SETUP, DS Channel
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
Type.... Outlet Input Data
Name.... Pond #1-Lower
Page 1.02
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, EI
Project Title: Searstone
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = RI
Structure Type
----------------- = Stand Pipe
-------------
------
# of Openings = 1
Invert Elev. = 362.00 ft
Diameter = 6.0000 ft
Orifice Area = 28.2743 sq.ft
Orifice Coeff. _ .600
Weir Length = 18.85 ft
Weir Coeff. = 3.000
K, Submerged = .000
K, Reverse = 1.000
Kb,Barrel = .000000 (per ft of full flow)
Barrel Length = .00 ft
Mannings n = .0000
Structure ID
Structure Type
--------------
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
WE
Weir-Rectangular
----------------
1
361.00 ft
1.50 ft
3.000000
Weir TW effects (Use adjustment equation)
SIN: 621701207003 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
Type.... Outlet Input Data Page 1.03
Name.... Pond #1-Lower
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, EI
Project Title: Searstone
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = Bl
Structure Type = Culvert-Circular
------------------------------------
No. Barrels = 1
Barrel Diameter = 3.5000 ft
Upstream Invert = 354.50 ft
Dnstream Invert = 345.00 ft
Horiz. Length = 336.00 ft
Barrel Length = 336.13 ft
Barrel Slope = .02827 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000 (forward entrance loss)
Kb = .005885 (per ft of full flow)
Kr = .5000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) = 1.146
T2 ratio (HW/D) = 1.293
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 358.51 ft ---> Flow = 63.00 cfs
At T2 Elev = 359.02 ft ---> Flow = 72.00 cfs
SIN: 621701207003 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
Type.... Outlet Input Data Page 1.04
Name.... Pond #1-Lower
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, El
Project Title: Searstone
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = B2
Structure Type
--------------- = Culvert-Circular
-
No. Barrels -------------
= 1 -------
Barrel Diameter = 3.5000 ft
Upstream Invert = 339.60 ft
Dnstream Invert = 336.00 ft
Horiz. Length = 72.09 ft
Barrel Length = 72.18 ft
Barrel Slope = .04994 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000 (forward entrance loss)
Kb = .005885 (per ft of full flow)
Kr = .5000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
Tl ratio (HW/D) = 1.135
T2 ratio (HW/D) = 1.282
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below Tl elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at Tl & T2...
At T1 Elev = 343.57 ft ---> Flow = 63.00 cfs
At T2 Elev = 344.09 ft ---> Flow = 72.00 cfs
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
Type.... Outlet Input Data
Name.... Pond #1-Lower
Page 1.05
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, EI
Project Title: Searstone
Project Comments:
OUTLET STRUCTURE INPUT DATA
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 30
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .10 cfs
Max. Q tolerance = .10 cfs
SIN: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
Type.... Composite Rating Curve
Name.... Pond #1-Lower
Page 1.06
File.... X:\Projects\SRF\SRF-05000\Storm\Construction Drawings\PondPack\SRF05000-MASTER.PPW
Title... Project Date: 2/26/2007
Project Engineer: J.C. Diaz, EI
Project Title: Searstone
Project Comments:
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q
Elev. Q
ft cfs
--------
361.00 -------
.00
361.20 .39
361.40 1.08
361.60 1.92
361.80 2.88
362.00 3.91
362.20 10.02
362.40 20.37
362.60 33.44
362.80 48.73
363.00 65.89
363.20 84.71
363.40 104.62
363.60 125.80
363.80 127.64
364.00 129.44
364.20 131.23
364.40 132.99
364.60 134.73
364.80 136.45
365.00 138.14
365.20 139.81
365.40 141.47
365.50 142.29
-------- Converge
TW Elev Error
ft +/-ft
-------- -----
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Notes
-------------------------
Contributing Structures
(no Q: RI,WE,B1,B2)
WE,B1,B2 (no Q: RI)
WE,B1,B2 (no Q: RI)
WE,B1,B2 (no Q: RI)
WE,B1,B2 (no Q: RI)
WE,B1,B2 (no Q: RI)
RI,WE,B1,B2
RI,WE,B1,B2
RI,WE,B1,B2
RI,WE,B1,B2
RI,WE,B1,B2
RI,WE,B1,B2
RI,WE,B1,B2
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
RI,B1,B2 (no Q: WE)
S/N: 6217012070C3 The John R. McAdams Company
PondPack Ver. 8.0058 Time: 10:36 AM Date: 2/23/2009
HY-8 Energy Dissipation Report
External Energy Dissipator
Parameter Value Units
Select Culvert and Flow
Crossing Pond 1
Culvert Culvert 1
Flow 132.85 cfs
Culvert Data
Culvert Width 3.5
Culvert Height 3.5
Outlet Depth 1.91
Outlet Velocity 0.04 ft/s
Froude Number .55
ailwater Depth .00
ailwater Velocity .00 ft/s
ailwater Slope SO .0927
External Dissipator Data
External Dissi ator Category Streambed Level Structures
External Dissi ator Type Ri ra Basin
Restrictions
Froude Number <3
Input Data
Condition to be used to Compute
Basin Outlet Velocity Best Fit Curve
D50 of the Ri ra Mixture
Note: Minimum HS/D50 = 2 is Obtained if
D50=0.965ft
D50 of the Ri ra Mixture .833
DMax of the Ripra Mixture 1.417
Results
Brink Depth 1.914
Brink Velocity 0.044 ft/s
Depth (YE) 1.640
Ri ra Thickness .126
Ri ra Foreslo a .8340
Check HS/D50
Note: OK if HS/D50 > 2.0
HS/D50 .842
HS/D50 Check HS/D50 is OK
Check HS/D50
Note: OK if 0.1 < D50NE < 0.7
Check D50NE .508
D50NE Check D50NE is OK
Basin Length LB 35.505
Basin Width 7.170
Apron Length 11.835
Pool Len th 3.670
Pool Depth (HS) .367
TVVNE 0.000
ailwater Depth TW) .000
[Average Velocity with TW I AO ft/s
Critical De th Yc) 0.773
verage Velocity with Yc .858 ft/s
Worksheet
Worksheet for Circular Channel
Project Description
Worksheet TO LS PIPE
Flow Element Circular Chann
Method Manning's Forr
Solve For Channel Depth
Input Data
Mannings Coeffic 0.013
Slope 005000 ft/ft
Diameter 15 in
Discharge 3.78 cfs
Results
Depth 0.87 ft
Flow Area 0.9 ft2
Wetted Perime 2.46 ft
Top Width 1.15 ft
Critical Depth 0.79 ft
Percent Full 69.4 %
Critical Slope 0.006587 ft/ft
Velocity 4.16 ft/s
Velocity Head 0.27 ft
Specific Energ 1.14 ft
Froude Numbe 0.83
Maximum Disc 4.91 cfs
Discharge Full 4.57 cfs
Slope Full 0.003424 ft/ft
Flow Type 5ubcritical
Project Engineer: JRM Employee
x:\...\storm\c:onstr-1\design-l\pondl I-1.fm2 The John R. McAdams Company, Inc. FlowMaster v6.0 [614b]
02/23/09 10:48:33 AM ©Haestad Methods, Inc. 3713rookside Road Waterbury, CT 06708 USA [phone] Page 1 of 1
SEARSTONE WATER QUALITY VOLUME DESIGN SHEET J.C. Diaz, PE
SRF-05000 Pond #1 LS 2/23/2009
I. CAI,CI J-A-HON OF DEPTH REQIT D IN SPi:YYMR BOX -*04;j T,9'f0
Q = 3.78 cfs from PondPack Output
Size of orifice = 15 inches
Area of orifice (A) = 1.227 sq ft
Apply orifice equation =_> Q = CDA?(2gh)
Assume CD = 0.6
Driving head on orifice (h) = 0.41 ft
Invert of pipe to level spreader = 337.60
Orifice centroid elevation = 338.23
Minimum invert of principal spillway bypass pipe= 338.63
the difference between the principal
spillway pipe invert and orifice centroid
elevation
Therefore, set invert of bypass pipe to elevation = 338.70
and invert pipe to level spreader to elevation = 337.60
_ WE
Q= 3.78 cfs from PondPack Output
Using 3 F per 1 cfs, level spreader length = 117.18 feet
Therefore, level spreader required for 1" event = 118 feet
1 in runoff Pond #1 LS
SEARSTONE WATER QUALITY VOLUME DESIGN SHEET J.C. Diaz, El
SRF-05000 Dry Pond #2 2/23/2009
1. CALCULATION OF I" VOLUNIE:fOR WATER QIIALITY
The runoff to the pond for the V storm detention requirement is calculated using the SCS curve number
method. Impervious areas that directly enter the pond are counted as Directly Connected Impervious
Areas (DCIAs). No infiltration calculation will be provided for these areas. Areas not directly connected
will be accounted for in a composite curve number.
Using basic SCS runoff methodology, with no adju5
to initial abstractions (0.2*S and 0.8*S).
Impervious Area, directly connected (DCIA) _
@CN=
Other areas draining to pond (not DCIA) =
@CN=
tments made
10.32 acres
98
9.10 acres
78
Runoff from DCIAs =>
Precipitation amount = 1.0 inches
S = 0.204 inches (calculated)
Q* = 0.791 inches (calculated)
Runoff volume = 29629 CF
Runoff from non-connected areas =>
Precipitation amount = 1.0 inches
S = 2.821 inches (calculated)
Q* = 0.058 inches (calculated)
Runoff volume = 1927 CF
Therefore, total runoff from precipitation in question = 31,556 CF
Total storage required for normal + storage pool = 31556 CF
Ks = 24941
b= 1.2618
Invert Elevation= 336
Stage (above invert) associated with this storage = 1.20 feet
1 Therefore, depth required above normal pool for storm storage = 1.20 feet
14.46 inches
Therefore set crest of principal spillway at stage = 1.20 feet
and EL = 337.20 feet
a???1'??7S.17n:?II,?3{:?SrL?3-Lfb?YlliG? ?• J 57b- ,?h ? ?. a.? 4i ?4?? Yn ?i? - _
Size of orifice = 6 inches
Invert of orifice= 336
Orifice centroid elevation = 336.25
Driving head on orifice (h) = 0.95 feet the difference between the principal
Apply orifice equation => spillway stage elevation and orifice
Q = CDA4(2gh) centroid elevation
Assume CD = 0.6
Area of orifice (A) = 0.196 square feet
Q= 0.92 cfs
Using 3 F per 1 cfs, level spreader length = 28.57 feet
Therefore, level spreader required for V event = 29 feet
1 in runoff Dry Pond #2
SEARSTONE WATER QUALITY VOLUME DESIGN SHEET J.C. Diaz, El
SRF-05000 Dry Pond #3 2/23/2009
l Gt lr'Y I1 FoRWATER QuALTrY
The runoff to the pond for the 1 " storm detention requirement is calculated using the SCS curve number
method. Impervious areas that directly enter the pond are counted as Directly Connected Impervious
Areas (DCIAs). No infiltration calculation will be provided for these areas. Areas not directly connected
will be accounted for in a composite curve number.
Using basic SCS runoff methodology, with no adjustments made
to initial abstractions (0.2*S and 0.8*S).
Impervious Area, directly connected (DCIA) = 1.04 acres
@ CN = 98
Other areas draining to pond (not DCIA) = 2.12 acres
@ CN = 78
Runoff from DCIAs =>
Precipitation amount = 1.0 inches
S = 0.204 inches (calculated)
Q* = 0.791 inches (calculated)
Runoff volume = 2986 CF
Runoff from non-connected areas =>
Precipitation amount = 1.0 inches
S = 2.821 inches (calculated)
Q* = 0.058 inches (calculated)
Runoff volume = 449 CF
Therefore, total runoff from precipitation in question = 3,435 CF
Total storage required for normal + storage pool = 3435 CF
Ks= 11169
b = 1.286
Invert Elevation= 324
spillway stage elevation and orifice
Apply orifice equation => Q = CDA4(2gh) centroid elevation
Assume Co = 0.6
Area of orifice (A) = 0.196 square feet
Q = 1.32 cfs
Stage (above invert) associated with this storage = 0.40 feet
Therefore, depth required above normal pool for storm storage = 0.40 feet
4.80 inches
Therefore set crest of principal spillway at stage = 2.20 feet
and EL = 326.20 feet

Size of orifice = 6 inches
Invert of orifice= 324
Orifice centroid elevation = 324.25
Driving head on orifice (h) = 1.95 feet the difference between the principal
Using 31' per 1 cfs, level spreader length = 40.93 feet
Therefore, level spreader required for 1" event = 41 feet
1 in runoff
Dry Pond #3
SE!kRSTONE WATER QUALITY VOLUME DESIGN SHEET I.C. Diaz, El
SRF-05000 Dry Pond #4 2/23/2009
'L 1CAS.i±1 it T t VA'iERQ>(7AL.I1Y
The runoff to the pond for the 1" storm detention requirement is calculated using the SCS curve number
method. Impervious areas that directly enter the pond are counted as Directly Connected Impervious
Areas (DCIAs). No infiltration calculation will be provided for these areas. Areas not directly connected
will be accounted for in a composite curve number.
Using basic SCS runoff methodology, with no adjus
to initial abstractions (0.2*S and 0.8*S).
Impervious Area, directly connected (DCIA) _
@CN=
Other areas draining to pond (not DCIA) =
@CN=
tments made
0.73 acres
98
0.55 acres
78
Runoff from DC1As =>
Precipitation amount = 1.0 inches
S = 0.204 inches (calculated)
Q* = 0.791 inches (calculated)
Runoff volume = 2096 CF
Runoff from non-connected areas =>
Precipitation amount = 1.0 inches
S = 2.821 inches (calculated)
Q* = 0.058 inches (calculated)
Runoff volume = 116 CF
Therefore, total runoff from precipitation in question = 2,212 CF
Total storage required for normal + storage pool = 2212 CF
Ks = 4902.4
b= 1.3276
Invert Elevation= 320
Stage (above invert) associated with this storage = 0.55 feet

1 Therefore, depth required above normal pool for storm storage = 0.55 feet
6.59 inches

Therefore set crest of principal spillway at stage = 1.70 feet
and EL = 321.70 feet
Big NO -
. _ r" . .
Size of orifice = 6 inches
Invert of orifice= 320
Orifice centroid elevation = 320.25
Driving head on orifice (h) = 1.45 feet the difference between the principal
spillway stage elevation and orifice
Apply orifice equation => Q = CDA4(2gh) centroid elevation
Assume CD = 0.6
Area of orifice (A) = 0.196 square feet
Q= 1.14 cfs
Using 3 F per 1 cfs, level spreader length = 35.29 feet
Therefore, level spreader required for I" event = 36 feet
1 in runoff Dry Pond #4