HomeMy WebLinkAboutDrainage ReportDRAINAGE REPORT
For
DWS, Inc.
Gateway Subdivision Phase 4
Forrest Drive and University Drive
College Station, Texas
Prepared by
Bury+ Partners -SA , Inc.
10000 San Pedro, Suite 100
San Antonio, Texas 78216
"I hereby certify that this report for the drainage design of the Gateway Subdivision, Phases 4,
was prepared under my supervision in accordance with the provisions of the City of College
Station Drainage Policy and Design Standards for the owners thereof. "
Registered Professional Engineer
State of Texas No. 93563
February 2005
}:\Drainage Reports\DWS, lnc\367-002\February 2005\tlysheet.doc.hs
TABLE OF CONTENTS
INTRODUCTION ............................................................................................ 1
METHODOLOGY FOR DETENTION DESIGN ...................................................... 1
EXISTING CONDITIONS ................................................................................ 2-3
PROPOSED CONDITIONS .............................................................................. 3-4
RESULTS .................................................................................................... 4-5
CONCLUSION ............................................................................................... 5
INSPECTION ................................................................................................. 3
EXIIlBITS
VICINITY MAP ................................................................................. EXHIBIT 1
EXISTING DRAINAGE AREA MAP ....................................................... EXHI13IT 2
PROPOSED DRAINAGE AREA MAP ..................................................... EXHIBIT 3
APPENDICES
CITY OF COLLEGE ST A TI ON SCS TABLES ........................................ APPENDIX A
SCS EXISTING CONDITIONS ........................................................... APPENDIX 13
SCS PROPOSED CONDITIONS .......................................................... APPENDIX C
~-------------BURY + PARTN E RS -----------------'
INTRODUCTION
The Gateway Subdivision Phase 4 is located near the intersection of University Drive and Forest
Drive in College Station, Brazos County, Texas. Please see the location map in Exhibit 1. For
Phase 4, the development consists of a ±6.625 acres in the western comer of the overall
development, as shown on Exhibits 2 and 3. These Exhibits also show a tributary to Burton Creek
that passes through the site. A FEMA Flood Study to determine the limits and elevations of the
100-year floodplain was previously prepared and submitted for approval by Mitchell & Morgan,
LLP.
The purpose of this drainage report is to analyze the pre-developed and storm water runoff
condition and to prove onsite detention will not be required by area DA3P. Instead, a modification
to the outfall structure of the regional detention pond built by The Home Depot will reduce the
overall runoff generated by the overall development.
The detention pond designed for the ±32 acre drainage area 2 (The Home Depot and future retail
space) was designed with the construction documents for The Home Depot and was built at the
same time. This detention pond was over-designed to account for the ultimate development of the
entire area. The calculations in this report will prove that changing the outfall structure of this pond
at the same time as developing DA3P, the overall storm water runoff at Point "A" will remain at or
below existing conditions.
In accordance with the City of College Station Ordinance #1728, the following narratives ,
calculations, and exhibits are submitted for your review, comments, and approval for the proposed
development.
METHODOLOGY FOR DETENTION DESIGN
The software package HEC-HMS, by the Hydrologic Engineering Center of the US Corps of
Engineers, was used for this detention design. The flow rates are based on the SCS method using a
24-hour, Type II storm for the City of College Station. The 24-hour rainfall depth, curve number
and initial loss are based on the City of College Station criteria. Please see Appendix A for these
variables. The calculations based on these conditions are shown in the detailed HEC-HMS output
and can be examined in the Appendices following this report.
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EXISTING CONDITIONS
The Existing Conditions Area Map (Exhibit 2) shows DA3P to be ±6.625 acres with a CN value of
75. All other drainage areas were accounted as they are now, except DA2, which was assumed as
ultimate development.
The figures for each drainage area and the peak flow of points A and B are summarized in the
following tables.
TABLEl
Drainage Area CN Tc Lag
Area (MI2) (SCS) (Min) (Min)
DAl 0.066407 77 16.7 10.0
DA2 0.049641 94 12.0 7.2
DA4 0.012625 77 10.0 6.0
DAlAP 0.009623 91 10.0 6.0
DAlBP 0.004841 91 10.0 6.0
DA2P 0.006159 75 18.2 10.92
DA3P 0.010352 75 10.0 6.0
DA4P 0.009075 75 10.0 6.0
TABLE2
Study 100 Yr 50Yr 25 Yr lOYr 5 Yr
Point (cfs) (cfs) (cfs) (cfs) (cfs)
A 787.8 690.1 609.2 493.6 394.9
B 211.2 183.2 159.9 127.4 99.8
Since the existing detention pond capacity is to be analyzed with this report, the following
computation were used based on the approved drainage/detention report for the Gateway
Subdivision Phase 1, dated August 2002 by Bury+ Partners, Inc.
As mentioned earlier, the pond was designed and built by The Home Depot as a regional detention
pond. It is oversized to detain extra storm water to keep the overall development below existing
flow. On the construction documents of The Home Depot, the outfall was designed as 2-36" pipes
with an invert of 261.0 feet and was constructed that way . However, due to an oversight, the
approved drainage report accounts for only 1-36" pipe. So as not to profit from this oversight, the
existing condition in this report assume only 1-36" pipe outfalls from the pond. The table below
shows the elevation-area-outflow for the pond as approved in the previous report and as used for
calculations in this report.
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l...----------------BURY+PARTNERS ------------------'
TABLE3
Contour Elevation Area (Acre) Outflow ( cfs) Notes
261 0.679522 0.00
262 1.387420 5.10
263 1.700367 12.95
264 2.013315 17.61
265 2.310331 43.14
266 2.607323 58.41
267 2.734619 70.44
268 2.861915 79.81
269 2.891736 86.76 Spillway elevation
270 2.921534 255.20 Top of earthen berm
PROPOSED CONDffiONS
The Proposed Drainage Area Map (Exhibit 3) shows DA3P with a proposed CN value of 96 and
DA2P with a proposed CN value of 94. All other drainage areas have the same CN as existing
conditions.
The figures for each drainage area and the peak flows are summarized in the following tables.
TABLE4
Drainage Area CN Tc Lag
Area (Ml2) (SCS) (Min) (Min)
DAl 0.066407 77 16.7 10.0
DA2 0.049641 94 12.0 7.2
DA4 0.012625 77 10.0 6.0
DAlAP 0.009623 91 10.0 6.0
DAlBP 0.004841 91 10.0 6.0
DA2P 0.006159 94 10.0 6.0
DA3P 0.010352 96 10.0 6.0
DA4P 0.009075 75 10.0 6.0
TABLES
Study 100 Yr 50Yr 25 Yr 10 Yr 5 Yr
Point (cfs) (cfs) (cfs) (cfs) (cfs)
A 768.4 674.3 596.1 486.2 391.7
B 244.7 216.1 192.2 158 .8 130.3
3
~--------------BURY+PARTNERS ----------------'
With the development of drainage area DA3P, the outfall structure of the regional detention pond
will be modified. This modification includes closing/plugging one of the 36" pipes, which
corresponds to the approved drainage report, and placing a restrictor with a 30" diameter opening
into the other 36" pipe. The size and volume do not have to be changed because the pond was
over-designed when it was originally built.
Table 6 below shows the new outflows along with the change in outflow of each 1 foot elevation.
TABLE6
Contour Elevation Outflow ( cfs) Change in Outflow Notes
(cfs)
261 0.00 0.00
262 3.30 -1.80
263 9.66 -3.29
264 13.90 -3.71
265 14.96 -28.18
266 21.76 -36.65
267 26.22 -44.22
268 30.02 -49.79
269 33.40 -53.36 Spillway elevation
270 198.46 -56.74 Top of earthen berm
RESULTS
The following table identifies the essential results of the detention model.
TABLE7
Study Point 100 Yr 50Yr 25 Yr lOYr 5 Yr
(cfs) (cfs) (cfs) (cfs) (cfs)
Existing A 787.8 690.1 609.2 493 .6 394.9
Proposed A 768.4 674.3 596.1 486.2 391.7
Net Difference -19.4 -15.8 -13.1 -7.4 -3.2
Existing B 211.2 183.2 159.9 127.4 99 .8
Proposed B 244.7 216.1 192.2 158.8 130.3
Net Difference +33.5 +32.9 +32.3 +31.4 +30.5
4
'-----------------BURY+PARTNERS ------------------'
Based on the above calculations, Study Point A, which is the most downstream point of interest,
shows a net decrease in peak flow for all investigated storm events. Since the existing detention
pond was oversized and the outflow was further restricted, full storm detainment in the 5-100 year
storms was achieved for DA3P without onsite detention.
At Point B, there is a net increase of 32.1 cfs on average. This increase in runoff is due to the
increase in the impervious cover on the subject tract. Since no future development can occur in
DA4P or between Study Point B and Study Point A, additional detention for the 5-100 year storm
events should only be required for increase in runoff generated at Study Point A.
CONCLUSION
The detention design restricts the post development runoff rates to the pre-development runoff rates
and provides more than adequate storage. Therefore, the detention design satisfies the City of
College Station Ordinance #1728 and should be approved.
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EXHIBIT 1
VICINITY MAP
"Bury+ Partners
ENGINEEl l NG SOLUTI ONS ,_ ........ ._. .....
......... n:1111• "" (11•,___ ra (a•,___ ..., ............. ~ ...
DATE: 02/17/05 SCALE: N.T.S.
VICINITY MAP
N.T.S.
COLLEGE STATION
GATEWAY ESTATES
COLLEGE STATION. TEXAS
DRAWN BY: VOO FILE: G:\JG7\02\EXHBTS\EX36702JIWG
EXHIBIT 1
SITE LOCATION MAP
PROJECT No.: 367-02
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EXHIBIT2
EXISTING DRAINAGE AREA MAP
Storm
Table I I I-3
24 Ho~r Ra1nfa11 Depths for 1Se1ected
Storm Return Periods
Return Period, II t II 24 Hour Rainfall Depth.
(Years) r (Inches)
2 4,5
5 6.2
10 '7. 4
.25 8,8
50 9.8
100 11. 0
1 From National Weather Service lsohyetal Charts For
Selected Return Periods
25
II p II
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Table III-4
Curve Numbers and Percent Impervious Afea
For Various Land Co ver and Land Use
Category
Land Cover:
Natur~l Woodlands
Natural Grasslands
Landscaped Areas
Impervious Areas·
{Pavements, Rooftops, etc.)
Land Uses:
Low Density Residential
Medium Density Residential
High Density Residential
Business/Cormiercial
Industrial
Percent Impervious ~
0
0
0
100
38
52
65
85
72
Curve Number
75
75
77
98
84
87
91
94
92
1 From uUrban Hydrology For Small Watersheds, Techn1ca.1 Release No. 55"
of the Soi 1 Co.nservation Service
... ,,<
26
\ ·-:'Ii \ '-;~ Tab(~ 4~1.-1, values for ~off cune numbers . Curve 1. Curye I, . t number . (in) number (In) 40 8.000 10 0.857 41 2.878 11 0.817 42 2.762 72 0.778 43 2.651 78 <J.740 44 2.545 74 ().'703 ,45 2.444 75 ().667 46 2.848 76 ·<l.682 47 2.255 77 0.697 48 2.167. 7$ 0.664 49 2.082 79 0".682 50' ·2.000 80 0.600 51 1.922 81 0.469 52. 1.846 82 0.4$9 68 1.7'14 83 o.4io 64 1.704 84 0.881 65 1.686 85. 0.858 66. 1.611 86 ()°.826 67 1.609 87 0.299. 68 1.«s gs 0.278 69 1.89{) gg 0.24.7 60 1.888 90 0.222 61 1.279 91 0.198 62 1.226 92 0.1'14 63• Ll75 93 0.161 64 1.126 94 O.J.lS 65 L07'l 95 0.105. 66 1.030 . t6 o.oss . .:'~ 67 0.985 tr o.062 68 0.Nl 98 0.00 69 o.899 .. "' ,fi I .
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APPENDIXB
SCS EXISTING CONDITIONS
l-IEC-l-JMS Project: Gateway Subdivision Basin Model: Existing
DA2 DAIAP DA1BP DA2P DA3P
Point B
Point A
Project
St art of Run
End of Run
Execution Time
HMS * Summary of Results
Gateway Subdivision
Basin Model
Met . Model
Run Name EX5yr
Existing Conditions
5 year storm
26Jan05 0000
27Jan05 0000
16Feb05 094 9 Control Specs St a ndar d
Hydrologic Discharge Ti me of Volume Drainage
Eleme n t Peak Peak (ac Area
(c fs) ft) (sq mi)
DAl 223 .92 26 Jan 05 1203 16.321 0 .0 66
60 11 Pipe 223.35 26 Jan 05 1204 1 6.310 0 .066
DA2 227 .79 26 Jan 05 1200 16.106 0 .050
DAlAP 45.397 26 Jan 05 1159 2.9893 0 .010
HD Pond 53 .595 26 Jan 05 1217 18.401 0.059
DAlBP 22.838 26 Jan 05 1159 1.5038 0.005
DA2P 16 .298 26 Jan 05 1204 1.1296 0.006
DA4P 29.444 26 Jan 05 1200 1.6674 0 .009
DA3P 33 .588 26 Jan 05 1200 1.9021 0 .010
Point B 99.831 26 Jan 05 1200 6.2030 0 .030
DA4 43.216 26 Jan 05 1159 2.4555 0 .013
Point A 394 .89 26 Jan 05 1202 43.370 0 .169
Project
Start of Run
End of Run
Execution Time
HMS * Summary of Results
Gateway Subdivision Run Name EXlOyr
26Jan05 0000
27Jan05 0000
1 6Feb05 0949
Basin Model
Me t . Model
Control Specs
Exi sting Conditions
10 year sto rm
Standard
Hydrologic Discharge Time of Volume Drainage
Element Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 278 .44 26 Jan 05 1203 20 .281 0.066
6011 Pipe 277 .92 26 Jan 05 1204 20 .269 0.066
DA2 272. 23 26 Jan 05 1200 19.274 0.050
DAlAP 54.491 26 Jan 05 1159 3.6006 0.010
HD Pond 62 .206 26 Jan 05 1217 22 .049 0.059
DAlBP 27.412 26 Jan 05 1159 1.8114 0.005
DA2P 21 .198 26 Jan 05 1204 1.4736 0 .006
DA4P 38 .199 26 Jan 05 1159 2 .1751 0.009
DA3P 43.574 26 Jan 05 1159 2 . 4811 0 .010
Point B 127 .38 26 Jan 05 1200 7 .9412 0.030
DA4 55 .536 26 Jan 05 1159 3 .1765 0 .013
Point A 493.60 26 Jan 05 1202 53.435 0 .169
Project
S t a rt of Run
End of Run
Execution Time
HMS * Summary of Results
Gateway Subdivision
Basin Model
Met. Model
Run Name EX25yr
Existing Conditions
25 y ear storm
26Jan05 0000
27Jan05 0000
16Feb05 0950 Control Specs Standa rd
Hydrologic Discharge Time of Volume Drainage
Element Peak Peak (ac Axea
(cfs) ft) (sq mi)
DAl 342 .44 26 Jan 05 1203 24.976 0 .066
6011 Pipe 341 .88 26 Jan 05 1204 24.963 0.066
DA2 324.03 26 Jan 05 1200 22. 971 0 .050
DAlAP 65 .076 26 Jan 05 1159 4.3150 0 .010
HD Pond 70 .805 26 Jan 05 1218 26 .306 0.059
DAlBP 32 .738 26 Jan 05 1159 2.1707 0.005
DA2P 26.999 26 Jan 05 1204 1.8880 0.006
DA4P 48 . 572 26 Jan 05 1159 2 .7864 0.009
DA3P 55 .407 26 Jan 05 1159 3.1785 0.010
Point B 159 .86 26 Jan 05 1200 10.024 0.030
DA4 70.030 26 Jan 05 1159 4 .0410 0.013
Point A 609.17 26 Jan 05 1202 65.334 0 .169
Project
Start of Run
End of Run
Execution Time
HMS * Sununary of Results
Gateway Subdivision Run Name EX5 0y r
Basin Model
Met. Model
26Jan05 0000
27Jan05 0000
16Feb05 0950 Contro l Specs
Existing Cond iti ons
50 year storm
St a ndard
Hydro log ic Di scharge Time of Volume Drainage
Ele me nt Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 3 88 .24 2 6 Jan 05 1203 2 8 .366 0 .06 6
60" Pi pe 3 87 .30 26 Jan 05 1204 2 8 .349 0.066
DA2 361. 01 26 Jan 05 1200 25 .612 0.050
DAlAP 72 . 626 26 Jan 05 1159 4 .8257 0 .010
HD Pond 75.560 26 Jan 05 1219 29.347 0 .059
DAlBP 36.535 26 Jan 05 1159 2 .4277 0.005
DA2P 31.168 26 Jan 05 1204 2.1900 0 .006
DA4P 56. 020 26 Jan 05 1159 3.2320 0.009
DA3P 63 .903 26 Jan 05 1159 3 .6868 0 .010
Point B 183 .17 26 Jan 05 1200 11.537 0.030
DA4 80.407 26 Jan 05 1159 4.6693 0 .013
Point A 690 .13 26 Ja n 05 1202 73.902 0 .169
Project
Start of Run
End of Run
Execution Time
HMS * Surrunary of Results
Gateway Subdivision Run Name EXlOOyr
Basin Model
Met. Model
26Jan05 0000
27Jan05 0000
16Feb05 0950 Control Specs
Existing Conditions
100 year storm
Standard
Hydrologic Disc harge Time of Volume Drainage
Element Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 443 .21 26 Jan 05 1203 32.461 0 .066
60" Pipe 442 .15 26 Jan 05 1204 32 .444 0 .066
DA2 405.38 26 Jan 05 1200 28.782 0.050
DAlAP 81.674 26 Jan 05 1159 5 .4390 0.010
HD Pond 80.921 26 Jan 05 1220 32.994 0.059
DAlBP 41. 088 26 Jan 05 1159 2 .7362 0 .005
DA2P 36.182 26 Jan 05 1204 2.5574 0.006
DA4P 64.972 26 Jan 05 1159 3.7741 0.009
DA3P 74 .114 26 Jan 05 1159 4.3052 0 .010
Point B 211.17 26 Jan 05 1200 13.373 0 .030
DA4 92.854 26 Jan 05 1159 5.4319 0.013
Point A 787 .82 26 Jan 05 1202 84.242 0 .169
HMS * Summary of Results for Point A
Project
Start of Run
End of Run
Execution Time
Computed Resul ts
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0815
Basin Model
Met. Model
Control Specs
Run Name EX5yr
Existing Conditions
5 year storm
Standard
Peak Outfl ow
Tot a l Outfl ow
394 . 89 (cfs)
4.82 (in)
Date/Time of Peak Outflow 26 Jan 05 1202
HMS * Summary of Results for Point B
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb0 5 0815
Basin Model
Met. Model
Control Specs
Run Name EX5yr
Existing Condition s
5 year storm
Standard
Peak Outflow
Total Outflow
99.831 (cfs)
3 .82 (in)
Date/Time of Peak Outflow 26 Jan 05 1200
HMS * Summary of Results for Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0815
Basin Model
Met. Model
Control Specs
Run Name EXlOyr
Existing Conditions
10 year storm
Standard
Peak Outfl ow
Total Outflow
609.17 (cfs )
7.26 (in)
Date/Time of Peak Outflow 26 Jan 05 1202
HMS * Summary of Results for Point B
Project : Gateway Subdivision
Start of Run
End of Run
Execution Time
Computed Results
26Jan05 0000
27Jan05 0000
16Feb05 0815
Basin Model
Met. Model
Control Specs
Run Name EXlOyr
Existing Conditions
10 year storm
Standard
Peak Outfl ow
Total Outflow
127.38 (cfs)
4.89 (in )
Date/Time of Peak Outflow 26 Jan 05 1200
HMS * Sununary of Results for Point A
Project : Gateway Subdivision
Start of Run
End o f Run
Execution Time
Computed Results
26Jan05 0000
27Jan05 0000
1 6Feb05 0816
Basin Model
Met. Model
Control Specs
Run Name EX25yr
Existing Conditions
25 year storm
Standard
Peak Outflow
Total Outflow
609.17 (cfs)
7 .26 (in)
Date/Time of Peak Outflow 2 6 Jan 05 1202
Project
Start of Run
End of Run
Exec ution Time
Computed Results
HMS * Summary of Results for Point B
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0816
Basin Model
Met. Model
Control Specs
Run Name : EX25yr
Existing Conditions
25 year storm
Standard
Peak Outflow
Total Outflow
159.86 (cfs)
6.18 (in)
Date/Time of Peak Outfl ow 26 Jan 05 1200
HMS * Sununary of Results for Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0816
Basin Mode l
Met. Model
Contr ol Specs
Run Name EX50yr
Existing Conditions
50 year storm
Standard
Peak Outflow
Total Outflow
690 .13 (cfs )
8.21 (in)
Date/Time of Peak Outflow 26 Jan 05 1202
HMS * Summary of Results for Point B
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0816
Basin Model
Met. Model
Control Specs
Run Name EX50yr
Existing Conditions
50 year storm
Standard
Peak Outflow
Total Outflow
183.17 (cfs)
7.11 (in)
Date/Time of Peak Outflow 26 Jan 05 1200
HMS * Summary of Results for Point A
Project
Start of Run
End of Run
Exec ution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0817
Basin Model
Met. Model
Control Specs
Run Name EXlOOyr
Exis t i ng Conditi ons
100 year storm
Standard
Peak Outflow
Tot a l Outflow
787 .82 (cfs )
9.36 (in)
Date/Time of Peak Outfl ow 26 Jan 05 1202
HMS * Summary of Results for Point B
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
1 6Feb05 0817
Basin Model
Met . Model
Control Specs
Run Name EXlOOyr
Exis ting Conditions
100 year storm
Standar d
Peak Outflow
Total Outfl ow
211 .17 (cfs)
8 .24 (in)
Date/Time of Peak Outflow 26 Jan 05 1200
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APPENDIXC
SCS PROPOSED CONDITIONS
HEC-l-I MS Project: Gateway Subdivision Basin Model: Proposed
DA1AP DA1BP DA2P DA3P
DA4
HD Pond (Mod)
Point B
DA1
Point A
I
Project
Start of Run
End of Run
Execution Time
HMS * Summary of Results
Ga t eway Subdivision Run Name PR5yr
Basin Mode l
Met. Model
26J a n 05 0000
27Jan05 0000
16Fe b 05 0951 Control Spec s
Proposed Conditio ns
5 year sto rm
Standard
Hydrologic Discharge Time of Volume Drainage
Element Pe ak Peak (ac Area
(cfs) ft) (sq mi)
DAl 223.92 26 Jan 05 1203 16.321 0 .066
60" Pipe 223 .35 26 Jan 05 1204 16 .310 0 .066
DA2 227 .79 26 Jan 05 1200 16.106 0 .050
DAlAP 45 .397 26 Jan 05 1159 2 .9893 0 .010
HD Pond (Mod) 23.061 26 Jan 05 1237 17.435 0 .059
DAlBP 21.422 26 Jan 05 1159 1. 4106 0 .005
DA2P 29.580 26 Jan 05 1159 1. 9989 0 .006
DA4P 29 .444 26 Jan 05 1200 1 .6674 0 .009
DA3P 49 .876 26 Jan 05 1159 3 .3920 0 .010
Point B 130 .30 26 Jan 05 1159 8.4689 0 .030
DA4 43.216 26 Jan 05 1159 2.4555 0.013
Point A 391 .69 26 Jan 05 1202 44.669 0.168
Pro ject
Start of Run
End of Run
Execution Time
HMS * Summary of Results
Gateway Subdivision Run Name PRl Oyr
26Jan05 0000 Basin Model
Me t . Model 27Jan05 0000
16Feb05 0951 Control Specs
Proposed Conditions
10 year storm
Standard
Hydrologic Discharge Time of Volume Drainage
Element Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 278.44 26 Jan 05 1203 20.281 0.066
60" Pipe 277 .92 26 Jan 05 1204 20.269 0 .066
DA2 272 .23 26 Jan 05 1200 19.274 0 .050
DAlAP 54 .491 26 Jan 05 1159 3.6006 0 .010
HD Pond (Mod) 26.366 26 Jan 05 1239 2 0 .642 0 .059
DAlBP 25 . 714 26 Jan 05 1159 1 .6991 0 .005
DA2P 35 .348 26 Jan 05 1159 2.3920 0 .006
DA4P 38.199 26 Jan 05 1159 2.1751 0.009
DA3P 59.554 26 Jan 05 1159 4.0533 0.010
Point B 158.81 26 Jan 05 1159 10.320 0 .030
DA4 55 .536 26 Jan 05 1159 3.1765 0 .013
Point A 486.20 26 Jan 05 1202 54.406 0 .168
Project
Start of Run
End of Run
Execution Ti me
HMS * Sununary of Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
Basin Model
Met. Model
Run Na me PR25yr
16Feb05 0951 Control Specs
Proposed Conditions
25 year storm
St andard
Hydrologic Discharge Time of Volume Drainage
Element Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 342.44 26 Jan 05 1203 24.976 0.066
60" Pipe 341 .88 26 Jan 05 1204 24.963 0 .066
DA2 324.03 26 Jan 05 1200 22.971 0 .050
DAlAP 65 .076 26 Jan 05 1159 4 .3150 0 .010
HD Pond (Mod) 29.610 26 Jan 05 1242 24.160 0 .059
DAlBP 30 .709 26 Jan 05 1159 2.0362 0.005
DA2P 42 .074 26 Jan 05 1159 2 .8508 0.006
DA4P 48. 572 26 Jan 05 1159 2.7864 0.009
DA3P 70.841 26 Jan 05 1159 4 .8250 0.010
Point B 192.20 26 Jan 05 1159 12.498 0 .030
DA4 70 .030 26 Jan 05 1159 4 .0410 0 .013
Point A 596 .11 26 Jan 05 1201 65 .663 0 .168
Pro ject
Start of Run
End of Run
Execution Time
HMS * Sununary of Results
Gateway Subdivision Run Name PR50yr
26Jan05 0000 Basin Model Prop o s ed Conditi ons
Met. Model 27Jan05 0000
16Feb05 0952 Control Specs
5 0 y ear storm
Standard
Hydrologic Discharge Time of Volume Drainage
Element Peak Peak (ac Area
(cfs) ft) (sq mi)
DAl 388 .24 26 Jan 05 1203 28 .366 0.066
6011 Pipe 387.30 26 Jan 05 1204 28.349 0.066
DA2 361 .01 26 Jan 05 1200 25 .612 0 .050
DAlAP 72.626 26 Jan 05 1159 4.8257 0 .010
HD Pond (Mod) 31.705 26 Jan 05 1244 26 .587 0 .059
DAlBP 34. 271 26 Jan 05 1159 2. 2772 0 .005
DA2P 46.876 26 Jan 05 1159 3.1786 0 .006
DA4P 56.020 26 Jan 05 1159 3.2320 0.009
DA3P 78.902 26 Jan 05 1159 5 .3762 0 .010
Point B 216.07 26 Jan 05 1159 14 .064 0 .030
DA4 80.407 26 Jan 05 1159 4.6693 0.013
Point A 674.33 26 Jan 05 1201 73.670 0 .168
Project
Start of Run
End of Run
Execution Time
HMS * Summary of Results
Gateway Subdi vision Run Name PRlOOyr
26Jan05 0000 Basin Model Proposed Conditions
27Jan05 0000 Met. Model
16Feb05 0952 Control Specs
100 year storm
Standard
Hydrologic Discharge Time o f Volume Drainage
Element Peak Peak (ac Area
(c fs) ft) (sq mi)
DAl 443.21 26 Jan 05 1203 32 .461 0 .066
6011 Pipe 442.15 26 Jan 05 1204 32 .444 0 .066
DA2 405.38 26 Jan 05 1200 28.782 0 .050
DAlAP 81.674 26 Jan 05 1159 5.4390 0 .010
HD Pond (Mod) 51.436 26 Jan 05 1230 29.565 0 .059
DAlBP 38.541 26 Jan 05 1159 2.5666 0 .005
DA2P 52 .636 26 Jan 05 1159 3.5720 0.006
DA4P 64 .972 26 Jan 05 1159 3.7741 0.009
DA3P 88.574 26 Jan 05 1159 6.0376 0 .010
Point B 244 . 72 26 Jan 05 1159 15.950 0.030
DA4 92.854 26 Jan 05 1159 5.4319 0 .013
Point A 768.44 26 Jan 05 1201 83.391 0 .168
HMS * Summary of Results for Poi nt A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdi vision
26Jan05 0000
27Jan05 0000
16Feb05 0910
Basin Model
Met. Model
Control Specs
Run Name PRSyr
Proposed Conditions
5 year storm
Standard
Peak Outflow
Total Outflow
391. 69 (cfs)
4. 97 (in)
Date/Time of Peak Ou tfl ow 26 Jan 05 1202
HMS * Summary of Resul ts for Point B
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
1 6Feb05 0910
Basin Model
Met. Model
Control Specs
Run Name PR5yr
Prop osed Conditions
5 year storm
Standard
Peak Outflow
Total Outfl ow
130.30 (c f s )
5.27 (in)
Date/Time of Peak Outflow 26 Jan 05 1159
HMS * Summary of Results f or Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0910
Basin Model
Met. Model
Control Specs
Run Name PRlOyr
Proposed Conditions
10 year storm
Standard
Peak Outflow
Total Outflow
486. 20 (cfs)
6.06 (in)
Date/Time of Peak Outflow 26 Jan 05 1202
HMS * Summary of Resu lts for Point B
Proj ect
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdi visi on
26Jan05 0000
27Jan05 0000
16Feb05 0910
Basin Model
Met. Model
Control Specs
Run Name PRlOyr
Propos ed Condi tions
10 year storm
Standard
Peak Outflow
Total Outflow
158. 81 (cfs)
6.42 (in)
Date/Time of Peak Ou t f l ow 26 Jan 05 1159
HMS * Summary of Resul ts for Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0909
Basin Model
Met. Model
Control Specs
Run Name PR25yr
Proposed Conditions
25 year storm
Standard
Peak Outflow
Total Ou tflow
596 .11 (cfs)
7. 31 (in)
Date/Time of Peak Outflow 26 Jan 05 1201
HMS * Summary of Re s u lts f o r Poi nt B
Pr o ject : Gateway Subdivision
Start of Run
End of Run
Execution Time
Computed Results
26Jan05 0000
27Jan05 0000
16Feb05 0909
Basin Model
Met. Mode l
Control Specs
Run Name PR25yr
Proposed Condition s
25 year s t o rm
Standa rd
Peak Outf l ow
Tot a l Ou tflow
1 92.20 (cfs)
7 . 78 (in )
Date/Time of Peak Out flow 26 J an 05 1159
HMS * Summary of Results for Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0909
Basin Mode l
Met. Model
Control Specs
Run Name PR50yr
Proposed Conditions
50 year storm
Standard
Peak Outflow
Total Outflow
674 .33 (cfs)
8.20 (in)
Date/Time of Peak Outflow 26 Jan 05 1201
HMS * Summary of Results for Point B
Project
Start of Run
End of Run
EKec u tion Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0909
Basin Model
Met. Model
Control Specs
Run Name PR50yr
Proposed Conditions
50 year storm
Standard
Peak Ou tfl ow
Total Outflow
216 . 07 {cfs)
8. 75 {in)
Date/Time of Peak Outflow 26 Jan 05 1159
HMS * Summary of Results for Point A
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0908
Basin Model
Met. Model
Control Specs
Run Name PRlOOyr
Proposed Conditions
100 year storm
Standard
Peak Outflow
Total Outfl ow
768. 44 (cfs)
9.28 (in)
Date/Time of Peak Outflow 26 Jan 05 1201
HMS * Summary of Results for Point B
Project
Start of Run
End of Run
Execution Time
Computed Results
Gateway Subdivision
26Jan05 0000
27Jan05 0000
16Feb05 0908
Basin Model
Met. Model
Control Specs
Run Name PRlOOyr
Proposed Conditions
100 year storm
Standard
Peak Outflow
Total Outflow
244.72 (cfs)
9.93 (in)
Date/Time of Peak Outfl ow 26 Jan 05 1159