HomeMy WebLinkAboutDrainage ReportDrainage Report — Executive Summary
Wellborn Business Park
College Station, Texas
February 29,2012
ENGINEER
Schultz Engineering, LLC
P.O. Box 11995
College Station, Texas 77842
Phone: (979) 764 — 3900
OWNER/DEVELOPER
Tripp Family Trust
1393 Seamist Lane
College Station, Texas 77845
(979) 219 — 2774
GENERAL DESCRIPTION AND LOCATION
This project consists of the development of Wellborn Business Park Phase I & 2 in Brazos County. Phase
1 & 2 are commercial developments, which will include the construction of sitework, utilities and other
infrastructure.
This project is located at 3808 McCullough Road, which is approximately 0.22 miles east of FM 2154
along the south side of McCullough Road.
Area: 4.16 acres
Existing Land Use: Vacant
Proposed Land Use: Commercial
Number of Lots: 1
Drainage Basin: Peach Creek Watershed
FEMA FIRM: #48041 CO200 — C, Dated July 2, 1992
Floodplain: None of the development lies within the floodplain.
HYDROLOGIC CHARACTERISTICS
The pre -development condition of the land is pasture. Exhibit A shows the pre -development topography
and the runoff flow direction.
GENERAL, STORMWATER PLAN
The drainage plan for this development will involve the installation of a diversion channel for offsite runoff
and an onsite detention pond. The diversion channel will collect and transmit the runoff, from the offsite
drainage area and a small portion of the onsite drainage area, to the existing roadside ditch along
McCullough Road. The majority of the Phase I & 2 runoff will be collected and transmitted to the
proposed detention pond and ultimately discharged into the existing roadside ditch along McCullough
Road. Exhibit B shows the post development topography and the runoff flow direction.
COORDINATION & STORMWATER PERMITTING
The project will require a Site Notice be prepared to comply with the Texas Commission for Environmental
Quality storm water permitting for the construction site. No other permits are anticipated for this project.
Page 1 of 5
Drainage Report — Executive Summary
Wellborn Business Park
College Station, Texas
February 29,2012
DRAINAGE DESIGN
General Information: Offsite stormwater runoff and a small portion of runoff from Phase 1 & 2 of the
development will be collected and transmitted through a channel and then
discharged into the McCullough Road right of way.
Stormwater runoff from Phase 1 & 2 of the development will be collected and
routed through the detention pond and then discharged into the McCullough
Road right of way by a 12" pipe with concrete sloped end treatment to match the
existing ditch slopes. The detention pond will reduce the peak runoff from the
developed site.
The runoff enters the detention pond from the parking lot through openings in
the curb.
The combined peak runoff from the offsite area and the detention pond will be
equal to or less than the pre -development peak runoff for the site and offsite
areas.
Offsite Flow Diversion Channel Analvsis
T, Methodology:
TR 55
T, Minimum:
10 minutes
Design Storm Events:
25-year
Manning's n Value:
0.040 Grass lined channel
Runoff Coefficients:
0.44 for contributing area
Design Constraints:
Design for 25-year storm with 1 foot of freeboard
Rational Equation:
The rational equation is utilized to determine peak storm water runoff rates for
the Diversion Channel design.
Q=CIA
Q = Flow (cfs)
A = Area (acres)
C = Runoff Coefficient
I = Rainfall Intensity (in/hr)
Design Software: Excel spreadsheets, AutoCAD Hydraflow Express
The software was used to compute the channel depths and discharge data.
Design Results: The data presented in the Appendices indicates the channel flow depth and size
are in accordance with the requirements of the design guidelines. See Appendix
A3 for results
Detention Facilitv Analvsis
T, Methodology:
TR 55
T, Minimum:
10 minutes
Design Storm Events:
2-year, 10-year, 25-year, 50-year and 100-year detention facility
Pond Discharge Pipe
Materials:
HDPE in accordance with ASTM C443, ASTM C76
Page 2 of 5
Drainage Report — Executive Summary
Wellborn Business Park
College Station, Texas
February 29, 2012
Manning's n Value:
.013
Runoff Coefficients:
0.35 Landscape areas and grass and 0.95 Pavement and building areas
Design Constraints:
Post -Development peak runoff less than or equal to pre -development peak
runoff
Rational Equation:
The rational equation is utilized to determine peak storm water runoff rates for
the Detention Facility design.
Q=CIA
Q = Flow (cfs)
A = Area (acres)
C = Runoff Coefficient
I = Rainfall Intensity (in/hr)
Design Software: Excel spreadsheets, AutoCAD Hydraflow Express, AutoCAD Hydraflow
Hydrographs Extension
The software was used to compute the pond storage and discharge data and the
pre and post -development peak runoffs and the routing of the flow through the
detention pond.
Design Results: The data presented in the Appendices and in the following tables indicates the
detention pond sizing and discharges are in accordance with the requirements of
the design guidelines.
Applicable Exhibits: Exhibit A — Pre -development Drainage Area Map
Exhibit B — Post -development Drainage Area Map
Exhibit C — Grading and Pond Details
Appendix Al — Drainage Area Summary
Appendix A2 — Time of Concentration Calculations
Appendix A3 — Diversion Channel Sizing
Appendix B — Pre & Post -Development Hydrographs
Appendix C — Detention Pond Data and Hydrographs
Appendix D — Technical Design Summary
Design Analysis: The Pre -development Drainage area, DA 101, is shown on Exhibit A.
The post -development drainage areas, DA 301 & DA 302, are shown on Exhibit
B. Since all of the runoff does not flow into the Detention Pond and some of the
runoff is diverted in the diversion channel, this drainage basin is divided into 2
areas DA 301 & DA 302. The design data and descriptions of the detention
pond outlet structures, discharge pipes and overflow spillways are found in
Appendix C.
The peak flow out of the detention ponds were determined by a Storage Routing
Analysis based on the Continuity Equation as follows: (Il+I2)+((2sl/dt)-
01)=((2s2/dt)=02). The time interval, dt, used was 1 minute. The calculations
and results of the Storage Routing Analysis were used to generate hydrograph
peak flows and graphs for the pre and post development conditions. A summary
of the peak flows from the site are shown in Table 1.
The hydrographs for the drainage areas that do not flow into the detention ponds
were combined with the detention pond outflows to determine the total post
development peak flows. Triangular hydrographs were created for each area
Page 3 of 5
Drainage Report - Executive Summary
Wellborn Business Park
College Station, Texas
February 29,2012
assuming the peak runoff value occurs at the time of concentration and then
goes to a runoff value of zero at two times the time of concentration.
The detention pond discharges into the McCullough Road roadside ditch. The
end of the discharge pipe will be mitered to match the slope of the ditch and
concrete riprap placed at its end to control erosion.
TABLE 1- Pre- & Post -Development Peak Discharge Comparison
Area #
Area
(Acres)
C
Tc
(Min.)
Pre
101
13.50
.40
36
Post
301
11.74
.41
36
Post
302
1.77
0.61
10
As shown in Table 2, the post -development peak outflow from the project site is
less than the allowable peak outflow for each design storm event. Additionally,
Tables 3 presents the maximum water surface and the amount of Freeboard for
the Detention Pond. The peak flow out of the detention pond and the maximum
water surface was determined by the Storage Routing Analysis and the
combining of the resulting hydrographs with the hydrographs from the areas that
do not flow into the ponds.
TABLE 2- Pre- & Post -Development Runoff Information - Detention Analysis
Q2
Q10
Q25
Q50
Q100
Location
cfs
cfs
cfs
cfs
cfs
Pre -Development
16.62
23.87
27.47
31.30
32.73
@ Outfall
Post -Development with Pond
Into Pond
6.83
9.32
10.65
12.04
12.57
Out of Pond
1.38
3.29
4.34
4.87
4.96
Post -Development
@ Outfall
16.09
22.70
25.93
29.43
30.76
(Combined Pond Discharge and
Area 301 Hydrograph)
Decrease in Peak Flow
0.53
1.17
1.54
1.87
1.97
Page 4 of 5
Drainage Report — Executive Summary
Wellborn Business Park
College Station, Texas
February 29, 2012
TABLE 3 — Summary of Pond 1 Maximum Water Surface Levels
Storm Event
Peak Flow out of
Pond, (cfs)
Water Surface
Elevation, ft.
Freeboard
ft.
2-year
1.38
337.56
1.44
10-year
3.29
337.94
1.06
25-year
4.34
338.03
0.97
50-year
4.87
338.12
0.88
100-year
4.96
338.16
0.84
Top of Berm = 339.00', Spillway Crest = 338.16'
Max water surface w/outlet clogged = 338.46', Freeboard = 0.54'
The detention pond has an overflow spillway which discharges when the outlet
structure is clogged. The detention pond spillway will be grass lined at the flat
crest. It is not anticipated that the overflow spillway will be used as the pond
can hold the 100-year storm event runoff.
The grading plan for the Detention Pond and the pond outlet structure and
discharge pipe details are shown on Exhibit C.
CONCLUSION
The offsite area diversion channel and onsite detention pond facility for Phase 1 & 2 development will
function within the requirements and restrictions of the BCS Drainage Design Guidelines.
CERTIFICATION
"This report for the drainage design of The Wellborn Business Par1c Phase 1 & 2, was prepared by me
in accordance with the provisions of the Bryan/College Station Unified Drainage Design Guidelines
for the owners of the property. All licenses and permits required by any and all state and federal
regulatory agencies for the proposed drainage improvements have been issued."
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SCHULTZ ENGINEERING, LLC
Josep . Sc ultz, P.E.
Page 5 of 5
EXHIBIT A
Pre Development Drainage Area Map
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Post Development Drainage Area Map
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INV. EL-335.00' 0 2.7%
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EL-339.00'
OVERFLOW SPILLWAY CREST
(100 YR W.S.) EL=338.16'
12" HDPE
INV. EL=336.00'
RASH RACK
IN TOP OF
;TRUCTURE
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W.S. ELEV.=338.46-
15' 4 TOP OF POND 339.00: 7
ELEV.-338.16'
POND OVERFLOW SPILLWAY
284 PROPOSED CONTOUR
------ EXISTING CONTOUR
BOUNDARY
DRAINAGE AREA LIMIT
TIME OF CONCENTRATION LINE
<-- FLOW ARROW
WELLBORN BUSINESS PARK DRAINAGE AREA SCALE
EXHIBIT
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EXHIBIT C
Grading and Pond Details
APPENDIX Al
Drainage Area Summary
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Time of Concentration Calculations
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Diversion Channel Sizing
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APPENDIX B
Pre & Post -Development Hydrographs
Pre & Post -Development Hydrographs
Appendix B
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Developed
Post
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Pre'_
Developed
post
Developed'
'Pro,
D,evelopedp
Post "j-
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re , r
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5yr
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0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1
0.46
0.41
0.66
0.59
0.79
0.68
0.87
0.78
0.91
0.81
77777777
0.92
0.84
1.33
1.21
1.58
1.39
1.74
1.59
1.82
1.66
3 ,
1.39
1.29
1,99
1.86
2.37
2.14
2.61
2.45
2.73
2.56
4
1.85
1.77
2.65
2.56
3.16
2.94
3.48
3.33
3.64
3.48
2.31
2.27
3.31
3.22
3.95
3.70
4.35
4.20
4.55
4.39
2.77
2,74
3.98
3.90
4.74
4.48
5.22
5.10
5.45
5.33
j
3.23
3.23
4.64
4.61
5.53
5.30
6.09
6.04
6.36
6.32
3.69
3.74
5.30
5.34
6.32
6.16
6.96
7.02
7.27
7.34
4.16
4.27
5.97
6.11
7.11
7.05
7.83
8.03
8.18
8.37
10
4.62
4.82
6.63
6.92
7.90
7.90
8.70
8.92
9.09
9.30
5.08
5.38
7.29
7.62
8.69
8.68
9.56
9.80
10.00
10.21
121
5.54
5.94
7.96
8.29
9.48
9.44
10.43
10.66
10.91
11.12
13
6.00
6.43
8.62
8.95
10.27
10.20
1130
11.52
11.82
12.11
7774777
6A6
6.89
9.28
9.60
11.06
10.94
12.17
12.78
12.73
13.95
77-15,
6.93
7.35
9.94
10.24
11.85
11.79
13.04
14.84
13.64
16.18
777H77
7.39
7.80
10.61
10.88
12.63
13.10
13.91
16.62
14.55
17.40
77771777
7.85
8.24
11.27
11.57
13.42
14.65
14.78
17.63
15.46
18.46
1 ll;e
8.31
8.68
11.93
12.36
14.21
16.06
15.65
18.59
16.36
19.43
19
8.77
9.12
12.60
13.52
15.00
17.12
16.52
19.51
17.27
20.29
20
9.23
9.55
13.26
14,53
15.79
17.89
17.39
20.34
18.18
21.14
21�
930
9.98
13.92
15.46
16.58
18.62
18.26
21.14
19.09
1 21.97
22,,I,
10.16
10.41
14.58
16.24
17.37
19.31
19.13
21.92
20.00
22.79
23'
10.62
10.83
15.25
16.88
18.16
19.97
20.00
22.69
20.91
23.59
24
11.08
11.25
15.91
17.42
18.95
20.59
20.87
23.44
21.82
24.39
'251
11.54
11.66
16.57
17.87
19.74
21.19
21.74
24.15
22.73
25.16
26:
12.00
12.08
17.24
18.26
20.53
21.57
22.61
24.80
23.64
25.93
27,1
12,47
12.49
17.90
18.62
21.32
21.84
23.48
25.42
24.55
26.64
28
12.93
12.89
18.56
18.97
22.11
22.08
24.35
26.01
25.46
27.26
29,
13.39
13.30
19.23
19.28
22.90
22.34
25.22
26.44
26.37
27.85
3V
13.85
13.70
19.89
19.56
23.69
22.64
26.09
26.46
1 27.27
28.27
31;
14.31
14.10
20.55
19.99
24.48
22.96
26.96
26.63
28.18
28.26
3211,'
14.78
14.50
2L21
20.51
25.27
23.45
27.83
26.98
29.09
28.49
c33
15.24
14.90
21.88
21.03
26.06
24.06
28.69
27.40
30.00
28.89
,W
15.70
15.30
22.54
21.55
26.85
24.66
29.56
28.03
30.91
29.35
35,,-,
16.16
15.70
23.20
2112
27.64
25.27
30.43
28.72
31.82
30.03
36-
16.6T
16.09
23.87-1
22.70,
28.43 r.-
25.93
�31,30
29.43'
32,73,
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37,,
16.39
15.88
23.53
22.39
28.03
25.58
30.87
28.97
32.28
30.29
3V:'
16.16
15.66
23.20
22.08
27.64
25.22
30.43
28.57
31.82
29.81
15.93
15.44
22.87
21,78
27.24
24.87
30,00
28.17
31.37
29.40
777740•�,._,
15.70
15.22
22.54
21.47
26,85
24.52
29.56
27.77
30.91
28.98
41
15.47
15.01
22.21
21.16
26.45
24.17
29.13
27.37
30.46
28,56
�,42 ,
15.24
14.79
21.88
20.85
26.06
23.82
28.69
26.97
30.00
28.14
J43
15.01
14.57
21.55
20.55
25.66
23.46
28.26
26.57
29.55
27.73
44
14.78
14.35
21.21
20.24
25.27
23.11
27.83
26.17
29.09
27.31
AS
14.54
14.13
20.88
19.93
24.88
22.76
27.39
25.77
28.64
26.89
46
14.31
13.92
20.55
19.62
24.48
22.41
26.96
25.37
28.18
26.47
47
14.08
13.70
20.22
19.32
24.09
22.05
26.52
24,97
27.73
26.06
48,
13.85
13.48
19.89
19.01
23.69
21.70
26.09
24.57
27.27
25.64
49.
13.62
13.26
19.56
18.70
23.30
21.35
25.65
24.17
26.82
25.22
50:
13.39
13.04
19.23
18.39
22.90
21.00
25.22
23.77
26.37
24.81
517'
13.16
12.83
18.89
18.09
22.51
20.65
24.78
2337
25.91
24.39
52;,
12.93
12.61
56
78
7:
1::::;1.47
22.11
20.29
24.35
22.97
25.46
23.97
51
12.70
2
N
1 :i 3
21.72
19.94
23.91
22.57
25.00
23.55
51
12.47
�22
12 7
17.90
1 17.16
21.32
19.59
23.48
22.17
24.55
23.14
5i_'
12.24
17.57
16.86
1 20.93
19.24 -1
23.04
21.77
T
1 4.09
1 22.72 _j
Pre
Developed
Post
b6ciope&
Pro J-
I)evelcipid
Post
Developed�
Pro,
Developed
'Post
Developed,
Developed
Post car
Developed
Pm
Developed,,
Post
Developed
2yr
i,
,_Aoyr
10yr
25yr
25yr,
50yr'
510yr,
100yr
I 00yr
Time(min)
Q(cfs),
Q(Ols)
Q(Cfs)
Q(Ols) f
Q(cfs)
Q(cfs)
Q(cfS)
Q(Cfs)
Q(cfS),
Q(cfs),
56
12.00
11.73
17.24
16.55
20.53
18.88
22.61
21.37
23.64
22.30
57
11.77
11.50
16.91
16.24
20.14
18.53
22.17
20.97
23.18
21.88
58-"'
11.54
11.26
16.57
15.93
19.74
18.18
21.74
20.57
22.73
21.47
12
11.31
11.03
16.24
15.63
19.35
17.83
21.30
20.17
22.27
21.05
60
11.08
10.80
5
15.91
15.32
18.95
17.48
20.87
19.77
21.82
20.63
10.85
10.57
9'
15.58
15.01
M56
17.12
20.43
19.37
21.37
20.22
627 -
7 t
6�
10��
10.34
525
15.25
14.70
18.16
16.77
20.00
18.97
20.91
19.80
... 63,�
10.39
10.11
14.92
42
9
14.40
17.77
16.42
19.56
18.57
20.46
19.39
10.16
9.88
1 4 5 8
14.58
E
14.09
17.37
16.07
19.13
18.18
20.00
18.96
9.93
9.66
1 425
14.25
13.78
16.98
15.71
18.70
17.78
19.55
18.55
9.70
9.43
13,92
1 3 92
13,47
16.58
15.36
18.26
17.38
19.09
18.13
427�
9.47
9.21
1 3 59
13.59
13.17
16.19
15.01
17.83
16.98
18.64
17.71
8.
9.23
8.98
13.26
12.85
M79
14.66
17.39
16.58 1
18.18
17.29
4t
9.00
8.76
12.93
12.53
15.40
14.30
16.96
16.18
17.73
16.88
,�,i42
8.77
8.53
12.60
1121
15.00
13.94
16.52
15.78
17.27
16.46'
7,44
8.54
8,31
12.26
11.89
14.61
13.57
16,09
15.37
16.82
16.04
183
8.31
8.09
11.93
11.56
14.21
13.20
15.65
14.96
16.36
15.62
8,08
7.87
11.60
11.24
13.82
12.84
15.22
14.54
15.91
15.19
7 85
764
11.27
10.93
13.42
12.47
14.78
14.13
15.46
14.75
7.62
7.42
10.94
10.61
1103
12.11
14.35
13.72
15.00
14.32
76
7.39
7.20
10.61
10.29
12.63
11.74
13.91
13.30
14.55
13.89
77
7.16
6.98
10.28
9.97
12.24
11.38
13.48
12.89
14.09
13.46
78
6.93
6.76
9.94
9.66
11.85
11.02
13.04
12.48
13.64
13.03
�'79
6.69
6.54
9.61
9.34
11.45
10.66
12.61
12.07
13.18
12.60
80-
6.46
6.32
9.28
9.03
11.06
10.30
12.17
11.66
12.73
12.18
w,
6,23
6.11
8.95
8.71
10.66
9.94
11.74
11.26
12.27
11.75
-82,
6.00
5.89
8.62
8.40
10.27
9.58
11.30
10.85
11.82
11.33
5,77
5.67
8.29
8.09
9.87
9.22
10.87
10.44
11.36
10.90
84
5.54
5.45
7.96
7.77
9.48
9.86
10.43
10.04
10.91
10.48
85
5.31
5.24
7.62
7.46
9.08
8.51
10.00
9.63
10.46
10.05
86
5.08
5.02
7.29
1 7.15
8.69
8.15
9.56
9.22
10.00
9.63
:87-
4.85
4.80
6.96
1 6.84
8.29
7.79
9.13
8.82
9.55
9.21
88
4.62
4.59
6.63
1 6.53
790--1
744
8.70
8.42
9.09
8.78
W
4.39
4.37
6.30
6.22
7.50
1 7.08
8.26
8.01
8.64
836
9VII
4.16
4.16
5.97
5.91
7.11
6.73
7.83
7.61
8.18
7.94
�91
3.92
3.94
5.64
5.60
6.71
6.38
1 7.39
7.21
7.73
7.52
92,',
3.69
3.73
5.30
529
6.32
6.02
6.96
1 6.81
7,27
7.10
93
3.46
3.51
4.97
4.98
5.92
5.67
652
1 6.40
6.82
6.68
94%-
3.23
3.30
4.64
4.68
5.53
5.32
6.09
6.00
6.36
6.26
95 ,
3.00
3.08
4.31
4.37
5.13
4,96
5.65
5.60
5.91
5.84
96,cl
2.77
2.87
3.98
4.06
4.74
4.61
5.22
5.20
5.45
5.43
97
2.54
2.65
3.65
1 3.76
4,34
4.26
4.78
4.80
5.00
5.01
1 98?
2.31
2.44
3.31
33
3.45
3.95
3.91
4.35
4.40
4.55
4.59
99,�
2.08
2.23
2.98
3.14
3.55
3.56
3.91
4.00
4.09
4.17
77-TUF777
1.85
2.01
2.65
53
2.84
3.16
3.21
3.48
3.61
3.64
1 3.76
7101 1",
1.62
1.80
2.32
2.53
2.76
2.86
3.04
3.21
3.18
3.34
102-,_1
1.39
1.59
1,99
2.23
2.37
2.51
2.61
2.81
2.73
2.92
le
1.15
1.38
1.66
RO.
1.92
1.97
2.16
2.17
2.41
2.27
2.51
104!e
0.92
1.16
1.33
L62
1.58
1.81
1.74
2.01
1.82
2,09
105
0.69
0.95
0.99
1.31
1.18
1.46
1.30
1.62
1.36
1.68
106
0.46
0.74
1.66
1.01
0.79
1 11
087
11
0.91
1.26
F -,10, e
0.23
0.53
575
0,39
0,76
0.43
0.82
0.45
0.85
> The post development flow includes Area 301 combined with the detention pond outflows from Area 302 being routed through the detention pond.
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APPENDIX C
Detention Pond Data and Hydrographs
Detention Pond
Appendix C
Detention Pond Summary
Detention Pond Storage
Design Storm
Inflow
Outflow
Plugged
W.S.
Plugged W.S.
gg
Outflow
Elevation
Elevation
(yr)
(cfs)
(cfs)
(cfs)
(ft)
(ft)
2
6.83
0 00----
-------- -
10
932
—1_38----
3.29
-----
0.64
-•.--337.56---
337.94
---------337.97--------
338.31
25
10.65
434
2.36
338.03
338.39
50
12.04
4.87
4.07
338.12
338.45
100
12.57
4.96
4.66
338.16
338.46
*Top of Berm= 339.00' Freeboard = 0.54'
Detention Pond
Appendix C
Detention Pond Area -Capacity Data
Pond Volume Equation
V = H * ][A1+A2 + (Al*A2)M] / 3)
V = volume, ft2
A = area, ft2
H = difference in elevation, ft
Detention Pond Storage
Elevation
Depth
Area
Volume
Cumulative
90 % Cumulative
Volume
Volume
(ft)
(ft)
(ft2)
(fe)
(ft')
(fe)
335.5
0.0
0
0
0
330
0
297
336.0
0.5
1977
330
------------- - - -----------
337.0
----- ---
1.5
--- ---
2984
-----------------------------------
21463
2,793
--------------------------------
2,514
--
338.0
2.5
2.
5,00 -
5,002
------950------------------------
3,950
6,743
6,06
6,068
339.0
3.5
9,010
6,908
13,651
12,286
Detention Pond
Appendix C
Elevation - Discharge Data
Depth - Discharge Data
Pond
2" x 18"
Opening
24" x
24"Opening
Overflow
Total Design
Elevation
Depth
Flow
Flow
Spillway
Flow
(ft)
(ft)
(cfs)
(cfs)
Flow (cfs)
(cfs)
335.5
0.0
0.00
0.00
0.00
0.00
336.0
0.5
0.20
0.00
0.00
0.20
337.0
1.5
1.04
0.00
0.00
1.04
338.0
2.5
0.83
3.33
0.00
4.16
339.0
3.5
0.10
6.03
31.80
37.93
Notes: 1. The Outlet Structure is a concrete structure with a weir to
limit flow. The weir opening is 2" wide x 18" tall from Elev 335.50'.
2. The overflow spillway is a weir over the top of the pond
with a width of 15'.
Wellborn Business Park
Detention Pond
Elevation - Discharge Data
Plugged Condition
Depth - Discharge Data
Pond
2" x 18"
Opening
24" x
24"Opening
Overflow
Total Design
Elevation
Depth
Flow
Flow
Spillway
Flow
(ft)
(ft)
(cfs)
(cfs)
Flow (cfs)
(efs)
335.5
0.0
0.00
0.00
0.00
0.00
336.0
0.5
0.00
0.00
0.00
0.00
337.0
1.5
0.00
0.00
0.00
0.00
338.0
2.5
0.00
0.00
0.00
0.00
339.0
3.5
0.00
0.00
31.80
31.80
Notes: 1. The Outlet Structure and pipe are plugged under this scenario.
2. The overflow spillway is a weir over the top of the pond
with a width of 15'.
Wellborn Business Park
Detention Pond
Appendix C
Storage Routing Analysis Parameters
t=60s
Detention Pond
Elevation
Depth
Discharge
Storage
2 s/t
2 s/t + O
(ft)
(it)
(O, cfs)
(s, cf)
335.50
0.0
0.00
0.0
0.0
0.00
336.00
0.5
0.20
296.6
9.9
10.09
337.00
1.5
1.04
2513.5
83.8
84.82
338.00
2.5
4.16
6068.3
202.3
206.44
339.00
3.5
6.13
12285.9
1 409.5
415.66
* The flow control structure is a 2" wide x 18" tall opening located in the
pond outfall structure. The overflow spillway is a 15' wide trapizodal weir
with crest at Elev. 338.16
Detention Pond - Plugged
Condition
Elevation
Depth
Discharge
Storage
2 s/t
2 s/t + O
(it)
(it)
(O, cfs)
(s, cf)
335.50
0.0
0.00
0.0
0.0
0.00
336.00
0.5
0.00
296.6
9.9
9.89
337.00
1.5
0.00
2513.5
83.8
83.78
338.00
2.5
0.00
6068.3
202.3
202.28
339.00
3.5
31.80
12285.9
i 409.5
441.33
* The flow control structure is a 2" wide x 18" tall opening located in the
pond outfall structure. The overflow spillway is a 15' wide trapizodal weir
with crest at Elev. 338.16
Pond Inflow & Outflow Hydrographs
Appendix C
inflow
Outflow
inflow
Outflow
Inflow
64ifloW
Inflow".:Outflow
ow
ow
Plugged
Put qW
2yhJ-�
2yr"
to
10yr
-2*
25A "
, : 50yr
'50yr,
I 00�r
'100r'
100
Thne(min')
Q(cfs)
Q(cfs)
Q(cfs)
k
Q(cfs)
Q(cfs)
Q(cfs)
Q(cfs)
Q(cfs)
Q(cfs)
Q(cfs)
Q(cfs)
1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.71
0.00
0.97
0.00
1.14
0.00
1.26
0.00
1.31
0.00
0.00
1.43
0.01
1.95
0.02
2.28
0.03
2.52
0.04
2.63
0.04
0.00
2,14
0.05
2.92
0.08
3.43
0.10
3.77
0.12
3.94
0.13
0.00
2.86
0.12
90
3.90
0.19
4.57
0.22
5.03
0.23
5.25
0.24
0.00
3.57
0.21
4.87
0.27
5.71
0.29
6.29
0.33
6.57
0.34
0.00
6^':""
4.28
0.28
5.85
0.36
6.85
0.40
7.55
0.45
7.88
0.47
0.00
5.00
0.35
6.82
0.47
8.00
0.54
8.81
0,61
9.19
0.64
0,00
8
5.71
0.45
7.179
0,62
9.14
0.71
10.06
0.82
10.51
0.86
0.00
9
6.42
0.56
8
8.77
0.79
10.28
0,93
11.32
1.05
11.82
1.08
0.00
to,"
'7
ILI 4,,�
0.70
.74,
1.01
77�
1.10
12.58,-:
1,17
7�
1.19
om
6.78
0.85
9.26
1.12 1
10,85
1.19
11.95
1.27 1
12.48
1.30
0.00
6.42
1.00
8.77
1.20
10.28
1.28
11.32
1.36
11.82
1.39
0.00
6.07
1.08
8.28
1.26
9.71
1.35 1
10.69
1.44
11.16 1
1.58 1
0,00
14
5.71
1.13
7.79
1.32
9.14
1.42
10.06
1.93
10,51
2.61
0.00
15
5.35
1.17
7,31
1.38
8,57
1.59
9.43
3.22
9.85
4.03
0.00
777
5,00
1.21
6.82
1.42
8.00
2.21
8.81
4.22
9.19
4.43
0.05
17"',"
4.64
1.24
6.33
1.53
7.43
3.08
8.18
4.45
8.54
4.68
0.37
18'_
4.28
1.27
5.85
1.72
6.85
3.82
7.55
4.64
7.88
4.84
1.66
19 ^'
3.93
1.30
536
2.29
1 6.28
4.20
6.92
4.78
7.22
4.89
2.76
3.57
1.32
4.87
2.72
5.71
4.28
6.29
4.84
6.57
4.93
3.79
21,'
3.21
1.34
4.38
3.05
5.14
4.33
1 5.66
4.86
1 5.91
4.95
1 438
22' '
2.86
1.35
3.90
3.24
4.57
-4.34
5.03
A.87',
5.25
"4.96
4.64
13:t,
2.50
1.36
3.41
3.29,
4.00
4.32
4.40
4.86
4.60
4.95
�,66
24 ... ...
2.14
1.37
2.92
3.24
3.43
4.27
3.77
4.84
3.94
4.94
4.50
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APPENDIX D
Technical Design Summary
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
The Cities of Bryan and College Station both require storm drainage design to follow these
Unified Stormwater Design Guidelines. Paragraph C2 of Section III (Administration) requires
submittal of a drainage report in support of the drainage plan (stormwater management plan)
proposed in connection with land development projects, both site projects and subdivisions.
That report may be submitted as a traditional prose report, complete with applicable maps,
graphs, tables and drawings, or it may take the form of a "Technical Design Summary". The
format and content for such a summary report shall be in substantial conformance with the
description in this Appendix to those Guidelines. In either format the report must answer the
questions (affirmative or negative) and provide, at minimum, the information prescribed in the
"Technical Design Summary" in this Appendix.
The Stormwater Management Technical Design Summary Report shall include several parts
as listed below. The information called for in each part must be provided as applicable. In
addition to the requirements for the Executive Summary, this Appendix includes several
pages detailing the requirements for a Technical Design Summary Report as forms to be
completed. These are provided so that they may be copied and completed or scanned and
digitized. In addition, electronic versions of the report forms may be obtained from the City.
Requirements for the means (medium) of submittal are the same as for a conventional report
as detailed in Section III of these Guidelines.
Note: Part 1 — Executive Summary must accompany any drainage report
required to be provided in connection with any land development project,
regardless of the format chosen for said report.
Note: Parts 2 through 6 are to be provided via the forms provided in this
Appendix. Brief statements should be included in the forms as requested,
but additional information should be attached as necessary.
Part 1 — Executive Summary Report
Part 2 — Project Administration
Part 3 — Project Characteristics
Part 4 — Drainage Concept and Design Parameters
Part 5 — Plans and Specifications
Part 6 — Conclusions and Attestation
STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT
Part 1 — Executive Summary
This is to be a brief prose report that must address each of the seven areas listed below.
Ideally it will include one or more paragraphs about each item.
1. Name, address, and contact information of the engineer submitting the report, and
of the land owner and developer (or applicant if not the owner or developer). The
date of submittal should also be included.
2. Identification of the size and general nature of the proposed project, including any
proposed project phases. This paragraph should also include reference to
applications that are in process with either City: plat(s), site plans, zoning requests,
STORMWATER DESIGN GUIDELINES Page 1 of 26 APPENDIX. D: TECH. DESIGN SUMMAR`
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
or clearing/grading permits, as well as reference to any application numbers or
codes assigned by the City to such request.
3. The location of the project should be described. This should identify the Named
Regulatory Watershed(s) in which it is located, how the entire project area is
situated therein, whether the property straddles a watershed or basin divide, the
approximate acreage in each basin, and whether its position in the Watershed
dictates use of detention design. The approximate proportion of the property in the
city limits and within the ETJ is to be identified, including whether the property
straddles city jurisdictional lines. If any portion of the property is in floodplains as
described in Flood Insurance Rate Maps published by FEMA that should be
disclosed.
4. The hydrologic characteristics of the property are to be described in broad terms:
existing land cover; how and where stormwater drains to and from neighboring
properties; ponds or wetland areas that tend to detain or store stormwater; existing
creeks, channels, and swales crossing or serving the property; all existing drainage
easements (or ROW) on the property, or on neighboring properties if they service
runoff to or from the property.
5. The general plan for managing stormwater in the entire project area must be
outlined to include the approximate size, and extent of use, of any of the following
features: storm drains coupled with streets; detention / retention facilities; buried
conveyance conduit independent of streets; swales or channels; bridges or culverts;
outfalls to principal watercourses or their tributaries; and treatment(s) of, existing
watercourses. Also, any plans for reclaiming land within floodplain areas must be
outlined.
6. Coordination and permitting of stormwater matters must be addressed. This is to
include any specialized coordination that has occurred or is planned with other
entities (local, state, or federal). This may include agencies such as Brazos County
government, the Brazos River Authority, the Texas A&M University System, the
Texas Department of Transportation, the Texas Commission for Environmental
Quality, the US Army Corps of Engineers, the US Environmental Protection Agency,
et al. Mention must be made of any permits, agreements, or understandings that
pertain to the project.
7. Reference is to be made to the full drainage report (or the Technical Design
Summary Report) which the executive summary represents. The principal
elements of the main report (and its length), including any maps, drawings or
construction documents, should be itemized. An example statement might be:
"One -page drainage report dated , one set of
construction drawings (_____sheets) dated and a
-page specifications document dated comprise
the drainage report for this project."
STORMWATER DESIGN GUIDELINES Page 2 of 26 APPENDIX, D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 2 — Proiect Administration
Start (Page 2.1)
Engineering and Design Professionals
Information .
Engineering Firm Name and Address:
Jurisdiction
Schultz Engineering, LLC
City: Bryan
P.O. Box 11995
College Station, Tx 77842
✓ College Station
Date of Submittal:
February 2012
Lead Engineer's Name and Contact Info.(phone, e-mail, fax):
Other:
Joseph A Schultz, PE entail: joeschultz84@verizon.net
Phone:764-3900 ax:764-3910
Supporting Engineering / Consulting Firm(s=NZA
er contacts:
Deitelo`
er / Owner' / Applicant
Information
Developer / Applicant Name and Address:
Phone and e-mail:
The Tripp Family Trust
979-219-2774
1393 Seamist Lane
College Station, Texas 77845
Property Owner(s) if not Developer / Applicant (& address):
Phone and e-mail:
scone as Developer
N/A
Project Identification "
Development Name: Wellborn Business Park Phase I & 2
Is subject property a site project, a single-phase subdivision, or part of a multi -phase subdivision?
Site Project If multi -phase, subject property is phase 2 of 2
Legal description of subject property (phase) or Project Area:
(see Section ll, Paragraph B-3a)
4.16 Acres Block ],Lot 1 Wellborn Business Park Andrew McMahan Survey A-167
If subject property (phase) is second or later phase of a project, describe general status of all
earlier phases. For most recent earlier phase Include submittal and review dates.
General Location of Project Area, or subject property (phase):
3808 McCullough Road, approximately 0.22 miles east of FM 2154 along the south side ofMccullough
Road. (South College Station)
In City Limits?
Extraterritorial Jurisdiction (acreage):
Bryan: acres.
Bryan: College Station:
College Station: 4.16 acres.
Acreage Outside ETJ:
STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 2 — Project Administration Continued (page 2.2)
Project Identification (continued)
Roadways abutting or within Project Area or
Abutting tracts, platted land, or built
subject property:
developments:
McCullough Road
No adjacent tracts platted, development prior to
annexation
Named Regulatory Watercourse(s) & Watershed(s):
Tributary Basin(s):
Peach Creek Watershed
Peach Creek
Plat Information For Project or' Subject Property (or, Phase)
Preliminary Plat File #: 11-00500105 Final Plat File #: 11-00500145 Date: 02-16-12
Name: Wellborn Business Park Status and Vol/Pg: Approved
If two plats, second name: N/A File #:
Status: Date:
Zoning Information, For Project or Subject Property (or Phase)
Zoning Type: A-0 Existing or Proposed? Existing Case Code:
Case Date Status:
Zoning Type: Existing or Proposed? Case Code:
Case Date Status:
Stormwater Management Planning For Project or, Subject Property (or Phase)
Planning Conference(s) & Date(s):
Participants:
N/A
Preliminary Report Required? N,1A Submittal Date Review Date
Review Comments Addressed? Yes NIA No_ In Writing? When?
Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation
explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any.
STORMWATER DESIGN GUIDELINES Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D — TECHNICAL DESIGN SUMMARY
Part 2 — Project Administration
Continued (page 2.3)
Coordination For Project
or Subject Property (or Phase) ,
Note: For any Coordination of stormwater matters indicated below, attach documentation
describing and substantiating any agreements, understandings, contracts, or approvals.
Dept.
Contact:
Date:
Subject:
Coordination
With Other
Departments of
Jurisdiction
City (Bryan or
College Station)
Coordination With
Summarize need(s) & actions taken (include contacts & dates):
Non -jurisdiction
City Needed?
Yes No ✓
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
Brazos County
Needed?
Yes _ No ✓
Summarize need(s) & actions taken (include contacts & dates):
Coordination with
TxDOT Needed?
Yes No ✓
Summarize need(s) & actions taken (include contacts & dates):
Coordination with
TAMUS Needed?
Yes No ✓
4?ermits For Projector Subject t Property (or Phase)
, . _ .
As to stormwater management, are permits required for the proposed work from any of the entities
listed below? If so, summarize status of efforts toward that objective ins aces below.
Entity
Permitted or
Status of Actions (include dates)
Approved ?
US Army Crops of
Engineers
No ✓ Yes _
US Environmental
Protection Agency
No ✓ Yes
Texas Commission on
General Per nit
It ivill be filed by the Construction Contractor.
Environmental Quality
150000
No Yes ✓
Brazos River
Authority
No ✓ Yes
STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 — Property Characteristics
Start (Page 3.1)
Nature and Scope of ProposedWork
Existing: Land proposed for development currently used, including extent of impervious cover?
None- Vacant
Site
Redevelopment of one platted lot, or two or more adjoining platted lots.
Development
✓ Building on a single lap tted lot of undeveloped land.
Project
Building on two or more platted adjoining lots of undeveloped land.
(select all
applicable)
Building on a single lot, or adjoining lots, where proposed plat will not form
a new street (but may include ROW dedication to existing streets).
Other (explain):
Subdivision
Construction of streets and utilities to serve one or more platted lots.
Development
Construction of streets and utilities to serve one or more proposed lots on
Project
lands represented by pending plats.
Site proiects: building use(s), approximate floor space, impervious cover ratio.
Describe
Subdivisions: number of lots by general type of use, linear feet of streets and
Nature and
drainage easements or ROW.
Size of
Commercial Offtce/Warehouse -16800 SF ofBaildings - 23% Impervious Cover
Proposed
Project
Is any work planned on land that is not platted
If yes, explain:
or on land for which platting is not pending?
✓ No Yes
FEMA Floodplains' .
Is any part of subject property abutting a Named Regulatory Watercourse
No ✓ Yes
(Section 11, Paragraph 131) or a tributary thereof?
Is any part of subject property in floodplain
No ✓ Yes Rate Map 48041CO200C
area of a FEMA-regulated watercourse?
Encroachment
into Floodplain s)
Encroachment purpose(s): Building site(s) Road crossing(s)
areas planned?
Utility crossing(s) Other (explain):
No ✓
N/A
Yes
If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA-
approved Flood Study to define allowable encroachments in proposed areas? Explain.
STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D — TECHNICAL DESIGN SUMMARY
Part 3 — Property Characteristics
Continued (Page 3.2)
Hydrologic Attributes of Subject
Property (or Phase)
Has an earlier hydrologic analysis been done for larger area including subject property?
Yes
Reference the study (& date) here, and attach copy if not already in City files.
Is the stormwater management plan for the property in substantial conformance with the
earlier study? Yes No If not, explain how it differs.
No
If subject property is not part of multi -phase project, describe stormwater management
plan for the property in Part 4.
If property is part of multi -phase project, provide overview of stormwater management plan
for Project Area here. In Part 4 describe how plan for subject property will comply
therewith.
The drainage plan for this development will involve the installation of an offsite flow diversion
channel and an onsite detention pond. The offsite flow diversion channel will collect and transmit
the runoff, from the offsite drainage area and a small portion of the onsite drainage area, to the
existing roadside ditch along McCullough Road. The majority of tine Phase 1 runoff will be
collected and transmitted to the proposed detention pond and ultimately discharged into the
existing roadside ditch along McCullough Road.
Do existing topographic features on subject property store or detain runoff? ✓ No Yes
Describe them (include approximate size, volume, outfall, model, etc).
Any known drainage or flooding problems in areas near subject property? ✓ No Yes
Identify:
Based on location of study property in a watershed, is Type 1 Detention (flood control) needed?
(see Table B-1 in Appendix B)
Detention is required. Need must be evaluated. Detention not required.
What decision has been reached? By whom?
If the need for
How was determination made?
Type 1 Detention
must be evaluated:
STORMWATER DESIGN GUIDELINES Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 - Property Characteristics
Continued (Page 3.3)
Hydrologic Attributes
of Subject
Property (or Phase);(continued)
Does subject property straddle a Watershed or Basin divide? ✓ No Yes If yes,
describesplits below. In Part 4 describe design conce t for handling this.
Watershed or Basin
Larger acreage
Lesser acres e
Above -Project Areas(Section II, Paragraph B3-a)
Does Project Area (project or phase) receive runoff from upland areas? No ✓ Yes
Size(s) of area(s) in acres: 1) 10.75 2) 3) 4)
Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable
concentrated section(s), small creek (non -regulatory), regulatory Watercourse or tributary);
Overland Sheet and Shallow Concentrated
Flow determination: Outline hydrologic methods and assumptions:
The Rational Method was used to determine peak runoff flows.
Does storm runoff drain from public easements or ROW onto or across subject property?
No ✓ Yes If yes, describe facilities in easement or ROW:
The right-of-way dedication area along the east boundary of the lot flows onto the lot
Are changes in runoff characteristics subject to change in future? Explain
Yes, the construction of a future street in the right-of-way dedication area will capture the majority of
the runoff being conveyed by the diversion channel.
Conveyance Pathways (Section II, Paragraph C2)
Must runoff from study property drain across lower properties before reaching a Regulatory
Watercourse or tributary? No ✓ Yes
Describe length and characteristics of each conveyance pathway(s). Include ownership of
property(ies).
The runoff will flow through the proposed detention pond or diversion channel then through the
existing roadside ditch before it discharges into the existing drainage way.
STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 — Property Characteristics
Continued (Page 3.4)
Hydrologic Attributes'of Subject Property (or Phase) (continued)
Conveyance Pathways (continued)
Do drainage
If yes, for what part of length? % Created by? _ plat, or
easements
instrument. If instrument(s), describe their provisions.
exist for any
part of
pathway(s)?
✓ No
Yes
Where runoff must cross lower properties, describe characteristics of abutting lower
property(ies). (Existing watercourses? Easement or Consent aquired?)
Pathway
Areas
Describe any built or improved drainage facilities existing near the property (culverts,
bridges, lined channels, buried conduit, swales, detention ponds, etc).
Roadside culverts along McCullough Road
Nearby
Drainage
Facilities
Do any of these have hydrologic or hydraulic influence on proposed stormwater
design? ✓ No Yes If yes, explain:
STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Desian Parameters
Start (Page 4.1)
Stormwater Management Concept
Discharge(s) From Upland Area(s)
If runoff is to be received from upland areas, what design drainage features will be used to
accommodate it and insure it is not blocked by future development? Describe for each area,
flow section, or discharge point.
Offsite Diversion Channel, if the fature street is constructed, the storm sewer system for the street will
collect and convey the storm water.
Discharge(s) To Lower Property(ies) (Section II, Paragraph El)
Does project include drainage features (existing or future) proposed to become public via
platting? ✓ No _Yes Separate Instrument? No Yes
Per Guidelines reference above, how will
Establishing Easements (Scenario 1)
runoff be discharged to neighboring
✓ Pre -development Release (Scenario 2)
property(ies)?
Combination of the two Scenarios
Scenario 1: If easements are proposed, describe where needed, and provide status of actions
on each. (Attached Exhibit # )
No easements are needed.
Scenario 2: Provide general description of how release(s) will be managed to pre -development
conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit # )
Detention pond
Combination: If combination is proposed, explain how discharge will differ from pre -
development conditions at the property line for each area (or point) of release.
If Scenario 2, or Combination are to be used, has proposed design been coordinated with
owner(s) of receiving property(ies)? No Yes Explain and provide
documentation.
STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D — TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.2)
Stormwater Management Concept (continued)
Within Project Area Of Multi -Phase Project
Identify gaining Basins or Watersheds and acres shifting:
Will project result
in shifting runoff
between Basins or
between
What design and mitigation is used to compensate for increased runoff
Watersheds?
from gaining basin or watershed?
✓ No
Yes
How will runoff from Project
1. With facility(ies) involving other development projects.
Area be mitigated to pre-
2 ✓ Establishing features to serve overall Project Area.
development conditions?
Select any or all of 1, 2,
3. ✓ On phase (or site) project basis within Project Area.
and/or 3, and explain below.
1. Shared facility (type & location of facility; design drainage area served; relationship to size of
Project Area): (Attached Exhibit # )
2. For Overall Proiect Area (type & location of facilities): (Attached Exhibit # )
Offsite diversion channel on east side ofproperty line and onsite detention pond on north side of
property.
3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in
subsequent questions of this Part.
Are aquatic echosystems proposed? ✓ No Yes In which phase(s) or
project(s)?
a
Are other Best Management Practices for reducing Stormwater pollutants proposed?
o-
No ✓ Yes Summarize type of BMP and extent of use:
N
m
Silt Fence, Construction Exit, Seeding, Grass Block Sod, Erosion protection
N
N o
0 Z
ca
If design of any runoff -handling facilities deviate from provisions of B-CS Technical
o.
Specifications, check type facility(ies) and explain in later questions.
U)
2
Detention elements Conduit elements Channel features
<
Swales Ditches Inlets Valley gutters _ Outfalls
Culvert features Bridges Other
STORMWATER DESIGN GUIDELINES Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D — TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.3)
Stormwater Management Concept (continued) ,,
Within Project Area Of Multi -Phase Project (continued)
Will Project Area include bridge(s) or culvert(s)? ✓ No Yes Identify type and
general size and In which phase(s).
If detention/retention serves (will serve) overall Project Area, describe how it relates to subject
phase or site project (physical location, conveyance pathway(s), construction sequence):
The proposed Detention Pond is on the north boundary of the tract and will be for phases 1 & 2 of the
development.
Within Or Serving Subject Property (Phase, or Site)
If property part of larger Project Area, is design in substantial conformance with earlier analysis
and report for larger area? Yes No, then summarize the difference(s):
Identify whether each of the types of drainage features listed below are included, extent of use,
and general characteristics.
Typical shape? Surfaces?
C'•
y u
Steepest side slopes:
Usual front slopes:
Usual back slopes:
Q) r
$
Flow line slopes: least
Typical distance from travelway:
=o
typical greatest
(Attached Exhibit # )
o
z
m
2
Are longitudinal culvert ends in compliance with B-CS Standard Specifications?
Yes No, then explain:
At intersections or otherwise, do valley gutters cross arterial or collector streets?
No Yes If yes explain:
0 U "O
N
Are valley gutters proposed to cross any street away from an intersection?
2 M z
No Explain: (number of locations?)
_ _Yes
STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.4)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Gutter line slopes: Least Usual Greatest
Are inlets recessed on arterial and collector streets? Yes No If "no",
identify where and why.
Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial
with arterial_or collector)? Yes No If no, explain where and why not.
C1•
CD
Will inlet size and placement prevent exceeding allowable water spread for 10-year
design storm throughout site (or phase)? Yes No If no, explain.
o�
Co
Sao curves: Are inlets placed at low points? Yes No Are inlets and
w
conduit sized to prevent 100-year stormflow from pending at greater than 24 inches?
s u
Yes No Explain "no" answers.
m
ro
m
N
E
Will 100-yr stormflow be contained in combination of ROW and buried conduit on
whole length of all streets? Yes No If no, describe where and why.
Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications?
Yes No If not, describe difference(s) and attach justification.
Are any 12-inch laterals used? ✓ No Yes Identify length(s) and where
used.
NN
Pipe runs between system
Typical Longest
a)access
points (feet):
aE
Are junction boxes used at each bend? Yes No If not, explain where
Nand
why.
G O
°z
E,
Are downstream soffits at or below upstream soffits?
Least amount that hydraulic
N
Yes No If not, explain where and why:
grade line is below gutter line
(system -wide):
STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.5)
Stormwater
Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Describe watercourse(s), or system(s) receiving system discharge(s) below
U
(include design discharge velocity, and angle between converging flow lines).
1) Watercourse (or system), velocity, and angle?
c
W E
2) Watercourse (or system), velocity, and angle?
0
c o
c 0
U G
E
3) Watercourse (or system), velocity, and angle?
T N
�
�v
O
O
a `o_
m
For each outfall above, what measures are taken to prevent erosion or scour of
Nreceiving
and all facilities at juncture?
d
1)
m
@
a
0)
2)
0
3)
Are swale(s) situated along property lines between properties? No Yes
Number of instances: For each instance answer the following questions.
Surface treatments (including low -flow flumes if any):
r
0
d
y }
Flow line slopes (minimum and maximum):
c
'm
v
0
Z
Outfall characteristics for each (velocity, convergent angle, & end treatment).
m
3
W
Will 100-year design storm runoff be contained within easement(s) or platted drainage
ROW in all instances? Yes No If "no" explain:
STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4,6)
Stormwater Management Concept,(continuad) ,
Within Or Serving Subject Property (Phase, or Site) (continued)
Are roadside ditches used? ✓ No Yes If so, provide the following:
tIs
25-year flow contained with 6 inches of freeboard throughout ? _ Yes _ No
Are top of banks separated from road shoulders 2 feet or more? Yes _ No
Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No
_
N
For any "no" answers provide location(s) and explain:
0
0
If conduit is beneath a swale, provide the following information (each instance).
Instance 1 Describe general location, approximate length:
Is 100-year design flow contained in conduit/swale combination? —Yes —No
N
If "no" explain:
U
0 m
Space for 100-year storm flow? ROW Easement Width
Z c
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
m
and maximum slopes:
slopes, design storm:
c
0
75
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
� c
m @
—
L
U
O
C
0 o
Access Describe how maintenance access is provided (to swale, into conduit):
o E
E
� o
= c
Instance 2 Describe general location, approximate length:
E
0 m
Is 100-year design flow contained in conduit/swale combination? —Yes —No
° 2
If "no" explain:
1° o.
c
or
Space for 100-year storm flow? ROW Easement Width
U
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
a
and maximum slopes:
slopes, design storm:
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
N
Access Describe how maintenance access is provided (to swale, into conduit):
STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.7)
Stormviater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
If "yes" provide the following information for each instance:
Instance 1 Describe general location, approximate length, surfacing:
c
a
o w
ui
Is 100-year design flow contained in swale? _ Yes No Is swale wholly
Cwithin
drainage ROW? Yes No Explain "no" answers:
Access Describe how maintenance access is provide:
a00i
0
Z
v
U
Instance 2 Describe general location, approximate length, surfacing:
D
0
c C1,
a Y
c
d
o E
r �
3
Is 100-year design flow contained in swale? Yes _ No Is swale wholly
W
within drainage ROW? Yes _ No Explain "no" answers:
0
a O
W
Access Describe how maintenance access is provided:
U_
Z
Q
Instance 3. 4, etc. If swales are used in more than two instances, attach sheet
providing all above information for each instance.
"New" channels: Will any area(s) of concentrated flow be channelized (deepened,
widened, or straightened) or otherwise altered? _ No .1Yes If only slightly
shaped, see "Swales" in this Part. If creating side banks, provide information below.
01.
c
Will design replicate natural channel? _ Yes ✓ No If "no", for each instance
00 a
describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year
o w
design flow, and amount of freeboard:
� 0
Instance 1:
}
Trapezoidal Shaped channel with 4:1 Side slopes at 1 %.
i-
0
Instance 2:
a
E 0
.0 Z
c
c
Instance 3:
m
L
U
STORMWATER DESIGN GUIDELINES Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.8)
Stornri Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Existing channels (small creeks): Are these used? ✓ No Yes
if "yes" provide the information below.
Will small creeks and their floodplains remain undisturbed? —Yes —No How
many disturbance instances? Identify each planned location:
For each location, describe length and general type of proposed improvement
(including floodplain changes):
For each location, describe section shape & area, flow line slope (min. & max.),
surfaces, and 100-year design flow.
a)
a)
c
c
Watercourses (and tributaries): Aside from fringe changes, are Regulatory
Watercourses proposed to be altered? ✓ No Yes Explain below.
c
Submit full report describing proposed changes to Regulatory Watercourses. Address
E
existing and proposed section size and shape, surfaces, alignment, flow line changes,
length affected, and capacity, and provide full documentation of analysis procedures
°
and data. Is full report submitted? Yes No If "no" explain:
a
E
N/A
c
c
All Proposed Channel Work: For all proposed channel work, provide information
U
requested in next three boxes.
If design is to replicate natural channel, identify location and length here, and describe
design in Special Design section of this Part of Report.
NIA
Will 100-year flow be contained with one foot of freeboard? ✓ Yes _ No If
not, identify location and explain:
Are ROW / easements sized to contain channel and required maintenance space?
✓ Yes No If not, identify location(s) and explain:
STORMWATER DESIGN GUIDELINES Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.9)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
How many facilities for subject property project? 1 For each provide info. below.
For each dry -type facilitiy:
Facility 1
Facility 2
Acres served & design volume + 10%
1.77
12576
100-yr volume: free flow & plugged
7278
9188
Design discharge (10 yr & 25 yr)
3.289
4.342
Spillway crest at 100-yr WSE?
✓ yes _ no
yes _ no
Berms 6 inches above plugged WSE?
✓ yes _ no
yes _ no
Explain any "no" answers:
r
For each facility what is 25-yr design Q, and design of outlet structure?
Facility 1: Inflow: 10.65, Outflow: 4.342, Riser structure with 2" x 18" opening
0
z
Facility 2: and 24" x 24" grate opening
Do outlets and spillways discharge into a public facility in easement or ROW?
Facility 1: ✓ Yes _ No Facility 2: —Yes —No
If "no" explain:
0
a
0
a.
For each, what is velocity of 25-yr design discharge at outlet? & at s ila Iwav?
Facility 1: 5.94 g, 0 Facility 2: &
.6
Are energy dissipation measures used? No ✓ Yes Describe type and
u_
location:
o
Concrete riprap outfall at ditch with rock riprap downstream
C
N
N
For each, is spillway surface treatment other than concrete? Yes or no, and describe:
Facility 1: Yes, Grass
Facility 2:
For each, what measures are taken to prevent erosion or scour at receiving facility?
Facility 1: Rock Riprap @ Culvert Outfall
Facility 2:
If berms are used give heights, slopes and surface treatments of sides.
Facility 1: 3, 4:1, Grass
Facility 2:
STORMWATER DESIGN GUIDELINES Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 —Drainage Concept and Design Parameters
Continued (Page 4.10)
Stormwater, Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Do structures comply with B-CS Specifications? Yes or no, and explain if "no":
Facility 1; Yes
aLD
LL G
Facility 2:
G r.
O C
C U
oFor
additional facilities provide all same information on a separate sheet.
Are parking areas to be used for detention? -Z— No Yes What is
maximum depth due to required design storm?
Roadside Ditches: Will culverts serve access driveways at roadside ditches?
No _ Yes If "yes", provide information in next two boxes.
Will 25-yr. flow pass without flowing over driveway in all cases? Yes _ No
Without causing flowing or standing water on public roadway? Yes No
Designs & materials comply with B-CS Technical Specifications? Yes —No
Explain any "no" answers:
C1•
u,
rn
c
oAre
culverts parallel to public roadway alignment? Yes No Explain:
2
U �
N }
Q
Creeks at Private Drives: Do private driveways, drives, or streets cross drainage
ways that serve Above -Project areas or are in public easements/ ROW?
NZ
_ No Yes If "yes" provide information below.
N
How many instances? Describe location and provide information below.
r
>
Location 1:
U
E
Location 2:
Location 3:
For each location enter value for:
1
2
3
Design year passing without toping travelway?
Water depth on travelway at 25-year flow?
Water depth on travelway at 100-year flow?
For more instances describe location and same information on separate sheet.
STORMWATER DESIGN GUIDELINES Page 19 of26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Desian Parameters
Continued (Page 4.11)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Named Regulatory Watercourses (& Tributaries): Are culverts proposed on these
facilities? No Yes, then provide full report documenting assumptions,
criteria, analysis, computer programs, and study findings that support proposed
design(s). Is report provided? Yes _ No If "no", explain:
Arterial or Maior Collector Streets: Will culverts serve these types of roadways?
NNo
Yes How many instances? For each identify the
@
location and provide the information below.
'00 m
Instance 1:
>- a
°v
Instance 2:
c
o
Instance 3:
c
2
o
Yes or No for the 100-year design flow:
1
2
3
Z
E
o
Headwater WSE 1 foot below lowest curb top?
n
Spread of headwater within ROW or easement?
E
W N
rn
Is velocity limited per conditions (Table C-11)?
N m
Explain any "no" answer(s):
N
2
O
U •—
@
?0 2 O
M a)
Minor Collector or Local Streets: Will culverts serve these types of streets?
No Yes How many instances? for each identify the
location and provide the information below:
na
Instance 1:
Nc
Instance 2:
o Co
u, o
Instance 3:
tf
For each instance enter value, or "yes" I "no" for:
1
2
3
u @
Design yr. headwater WSE 1 ft. below curb top?
Q a,
100-yr. max. depth at street crown 2 feet or less?
E
Product of velocity (fps) & depth at crown (ft) = ?
o
Is velocity limited per conditions (Table C-11)?
Limit of down stream analysis (feet)?
Explain any "no" answers:
STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.12)
Stormi4pter Management concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside
ditch intersects) provide information requested in next eight boxes.
Do culverts and travelways intersect at 90 degrees? _ Yes No If not,
identify location(s) and intersect angle(s), and justify the design(s):
Does drainage way alignment change within or near limits of culvert and surfaced
approaches thereto? No _ Yes If "yes" identify location(s), describe
change(s), and justification:
Are flumes or conduit to discharge into culvert barrel(s)? No _ Yes If yes,
identify location(s) and provide justification:
Are flumes or conduit to discharge into or near surfaced approaches to culvert ends?
No _ Yes If "yes" identify location(s), describe outfall design treatment(s):
0
c
C
0
U
N
Is scour/erosion protection provided to ensure long term stability of culvert structural
�j
components, and surfacing at culvert ends? Yes _ No If "no" Identify
locations and provide justification(s):
Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or
drainage easements/ ROW? _ Yes _ No if not, why not?
Do appreciable hydraulic effects of any culvert extend downstream or upstream to
neighboring land(s) not encompassed in subject property? _No Yes If
"yes" describe location(s) and mitigation measures:
Are all culvert designs and materials in compliance with B-CS Tech. Specifications?
Yes _ No If not, explain in Special Design Section of this Part.
STORMWATER DESIGN GUIDELINES Page 21 of26 APPENDIX. D: TECH. DESIGN SUMMAR`
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.13)
Stormwater Management Concept (continued)"
Within Or Serving Subject Property (Phase, or Site) (continued)
Is a bridge included in plans for subject property project? ✓ No Yes
If "yes" provide the following information.
Name(s) and functional classification of the roadway(s)?
What drainage way(s) is to be crossed?
U)
a
rn
m`
A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical,
hydrologic, and hydraulic factors) must accompany this summary report. Is the report
provided? —Yes —No If "no" explain:
Is a Stormwater
Provide a general description of planned techniques:
Pollution Prevention
Construction Exits, Sediment Pond, Silt Fence, Revegetation
Plan (SW3P)
0
established for
project construction?
m
No ✓ Yes
Special Designs — Non -Traditional Methods
Are any non-traditional methods (aquatic echosystems, wetland -type detention, natural stream
replication, BMPs for water quality, etc.) proposed for any aspect of subject property project?
✓ No _ Yes If "yes" list general type and location below.
Provide full report about the proposed special design(s) including rationale for use and
expected benefits. Report must substantiate that stormwater management objectives will not
be compromised, and that maintenance cost will not exceed those of traditional design
solution(s). Is report provided? Yes No If "no" explain:
STORMWATER DESIGN GUIDELINES Page 22 of26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.14)
Stormwater Management Concept (continued) .
Within Or Serving Subject Property (Phase, or Site) (continued)
Special Designs — Deviation From B-CS Technical Specifications
If any design(s) or material(s) of traditional runoff -handling facilities deviate from provisions of
B-CS Technical Specifications, check type facility(ies) and explain by specific detail element.
Detention elements Drain system elements Channel features
Culvert features Swales Ditches Inlets _Outfalls
Valley gutters Bridges (explain in bridge report)
In table below briefly identify specific element, justification for deviation(s).
Specific Detail Element
Justification for Deviation (attach additional sheets if needed)
1)
2)
3)
4)
5)
Have elements been coordinated with the City Engineer or her/his designee? For each item
above provide "yes" or "no", action date, and staff name:
1)
2)
3)
4)
5)
Design Parameters
Hydrology
Is a map(s) showing all Design Drainage Areas provided? ✓ Yes No
Briefly summarize the range of applications made of the Rational Formula:
Detention design and Channel sizing
What is the size and location of largest Design Drainage Area to which the Rational Formula
has been applied? acres Location (or identifier):
STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.15)
Design Parameters (continued).
Hydrology (continued)
In making determinations for time of concentration, was segment analysis used?
_ No ✓ Yes In approximately what percent of Design Drainage Areas? 100 %
As to intensity -duration -frequency and rain depth criteria for determining runoff flows, were any
criteria other than those provided in these Guidelines used? ✓ No _Yes If "yes"
identify type of data, source(s), and where applied:
For each of the stormwater management features listed below identify the storm return
frequencies (year) analyzed (or checked), and that used as the basis for design.
Feature
Analysis Year(s)
Design Year
Storm drain system for arterial and collector streets
Storm drain system for local streets
-
-
Open channels
100
25
Swale/buried conduit combination in lieu of channel
_
_
Swales
Roadside ditches and culverts serving them
-
-
Detention facilities: spillway crest and its outfall
2,10, 25, 50, 100
100
Detention facilities: outlet and conveyance structure(s)
2,10, 25, 50,100
100
Detention facilities: volume when outlet plugged
100
100
Culverts serving private drives or streets
-
-
Culverts serving public roadways,
Bridges: provide in bridge report.
Hydraulics
What is the range of design flow velocities as outlined below?
Design flow velocities;
Gutters
Conduit
Culverts
Swales
Channels
Highest (feet per second)
Z45
Lowest (feet per second)
Z03
Streets and Storm Drain Systems Provide the summary information outlined below:
Roughness coefficients used: For street gutters:
For conduit type(s) Coefficients:
STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D — TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.16)
Design Parameters (continued)
Hydraulics (continued)
Street and Storm Drain Systems (continued)
For the following, are assumptions other than allowable per Guidelines?
Inlet coefficients? —No —Yes Head and friction losses —No —Yes
Explain any "yes" answer:
In conduit is velocity generally increased in the downstream direction? Yes No
Are elevation drops provided at inlets, manholes, and junction boxes? —Yes —No
Explain any "no" answers:
Are hydraulic grade lines calculated and shown for design storm? —Yes No
For 100-year flow conditions? Yes _No Explain any "no" answers:
What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify
each location and explain:
Open Channels If a HEC analysis is utilized, does it follow Sec VI.F.5.a? _ Yes _ No
Outside of straight sections, is flow regime within limits of sub -critical flow? Yes No
If "no" list locations and explain:
Culverts If plan sheets do not provide the following for each culvert, describe it here.
For each design discharge, will operation be outlet (barrel) control or inlet control?
Entrance, friction and exit losses:
Bridges Provide all in bridge report
STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D -TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.17)
Design Parameters (continued)
Computer Software
What computer software has been used in the analysis and assessment of stormwater
management needs and/or the development of facility designs proposed for subject property
project? List them below, being sure to identify the software name and version, the date of the
version, any applicable patches and the publisher
Excel spreadsheets, AutoCAD Hydraflow Express, AutoCAD Hydraflow Hydrographs
Part 5 - Plans and Specifications
Requirements for submittal of construction drawings and specifications do not differ due to use of a
Technical Design Summary Report. See Section III, Paragraph C3.
Part 6 - Conclusions and Attestation
Conclusions, -
Add any concluding information here: The stormwater system and detention facilities are designed in
accordance with the BCS Drainage Design Guidelines.
Attestation
Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical
Design Summary Drainage Report by signing and sealing below.
"This report (plan) for the drainage design of the development named in Part B was prepared
by me (or under my supervision) in accordance with provisions of the Bryan/College Station
Unified Drainage Design Guidelines for the owners of the property. All licenses and permits
required by any and all state and federal regulatory agencies ffor they proposed drainage
improvements have been issued or fall under applicable gene�rr�lt`.TE@��
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License Prof sional Engineer 105EPH P.
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STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009