HomeMy WebLinkAboutDrainage Design LetterSchultz Engineering, LLC
Office: 979.764.3900
Fax: 979.764.3910
July 10, 2012
Alan Gibbs, P.E.
City Engineer
Development Services
City of College Station
College Station, Texas
RE: DRAINAGE DESIGN
PREVIROSE SCHOOL PROJECT (LOT 1, BLOCK 2 — TOWER POINT SUBDIVISION
PH. 12)
COLLEGE STATION, TEXAS
Mr. Gibbs:
Accompanying this letter are the construction plans for the Primrose School Project. The
drainage system depicted in the plans is to be privately maintained and no additional public
drainage infrastructure is being proposed. The outfall for this system connects to storm drain
that was designed by Walter P. Moore in the plan set titled "Tower Point Infrastructure Plans for
Phase 12, Lots 1-3, Block 2" and the associated Drainage Report. The 10 yr design flow for the
24" RCP Storm Sewer Stub -out designed by Walter P. Moore is 15.90 cfs. The 10 yr design flow
for the Pr' ose School storm sewer pipe that connects to the 24" RCP Storm Sewer Stub -out is
9.43 cfs.✓
The above referenced plans and associated Drainage Report. account for full build out of Lot 1.
The private drainage system for the Primrose School and its calculations are attached to this letter
for review and are within the assumptions for stormwater runoff, collection and piping. The
infrastructure in the "Tower Point Infrastructure Plans for Phase 12, Lots 1-3, Block 2" plans was
designed to handle runoff from this project, so its capacity is not being exceeded. As a result, a
separate drainage report is not being submitted with this project. If you have questions regarding
the proposed or existing drainage system for this project, please feel free to contact me at your
convenience.
Sincerely, �'r""
3�
..
JOSEPH P. 5
...........
J Schultz, P.E. ' 6588
Civil Engineer,
7• 10 -"2
P.O. Box 11995 • College Station, Texas 77d42 F-12327
schultzengineeringllc.com SCHULTZ ENGINEERING, LLC.
Private Storm Sewer System
Calculations
EXHIBIT A
Drainage Area Exhibit
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S RVEYEO DESIGNED OPAWN All.JOB NO. OgiE
KLING OLD DLD JPS 12212 JULYM2
wal
SCALE IN FEET
-- SCALE EXHIBIT
PRIMROSE SCHOOL PROJECT DRAINAGE AREA I�L
TOWER POINT SUBDIVISION — PHASE 12 GNI o w ,•= a
LOT 1, BLOCK 2 — COLLEGE STATION, TX EXHIBIT mmxGs us: 1:1
FItENaME: 12-212
EXHIBIT B
Storm Sewer Layout
77o,
271
—272
271 271----272 - z73 272 271 269- -
269
F-- 2fie 1 iI{
Ii I I i I #101T / -60 69 I I #INLE201T
\ L
I I e �� I i I PIPE PIPE PIPE '2 '9 PIPE PIPE PIPE
#101 #103 #102 #202 #203 #201
Ii 4 I I m I i PIPE `.
PIPE ... -. (Y4- #204
I I #104 INLET-
jjj INLET INLET INLET #203
#103 #102 #202 \ PIPE PERFORATED
nJ_ _ _ _ _ — — 1- #205 PIPES
I INLET PIPE ry<o /I\ #206
I I #104 _ BJ #207 -
I I 106
PIPE PIPE PERFORATED
#208 #209 INLET PIPE
PIPE #205
I I I PIPE I #210 #21E
1 I #107 / IT INLET
- PPIE
ERFORATED ` #272 PIPE i #20PIPE 6 ti
I i I I F PIPE , 1 #213
#214 INLET,
I I PERFORATEDPIPES i #109 269PIPE
,
PIPE .. #215 ~
PIPE�-.. JUNCIIIONJBO% #216 `
# -�. 267 /
266-266 r PIPE m
INLET #208 P
PIPET
#281#219
INLET
\ ti #209
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SIIPVEYED DESONEO OflAWN PPPNOVEO JOBNO. DALE
HUNG DID DLD JPS 12-212 JULY 2012
SCALE IN FEET
PRIMROSE SCHOOL PROJECT STORM SEWER SCALE EXHIBIT
�fl�L
TOWER POINT SUBDIVISION -PHASE 12 LA YC� UT
LOT 1, BLOCK 2 - COLLEGE STATION, TX RDII,„G BL „
Fl. NAME: 12-212
APPENDIX A
Drainage Area Summary
Primrose School College Station
Appendix A
Proposed Storm Sewer and Detention Facility Analysis
Drainage Area Summary
10 year storm
100 year storm
Area, A
C
t'
110
Qm
1100
Q100
Area #
(acres)
(min)
(in/hr)
Ids)
(inlhr)
Ids)
300
0.270
0,800
10.0
8.635
1.87
11.639
2.51
301
0.280
0.800
10.0
8.635
1.93
11.639
2.61
302
0.030
0.800
10.0
8.635
0.21
11.639
0.28
303
0.030
0.800
10.0
8.635
0.21
11.639
0.28
304
0.030
0.800
10.0
8.635
0.21
11.639
0.28
305
0.030
0.800
10.0
8.635
0.21
11.639
0.28
306
0.060
0.800
10.0
8.635
0.41
11.639
0.56
307
0.240
0.800
%0
8.635
1.66
11.639
2.23
308
0.060
0.800
10.0
8.635
0.41
11.639
309
0.040
0.800
10.0
8.635
0.28
11.639
_ _0.56 _
0.37
310
0.020
0.800
10.0
8.635
0.14
11.639
0.19
311
0.020
0.800
10.0
8.635
0.14
11.639
0.19
312
0.730
0.350
20.0
6.209
1.59
8.430
2.15
400
0.040
0.500
10.0
8.635
0.17
11.639
0.23
The Rational Method:
Q = CIA
Q = Flow (cfs)
A = Area (acres)
C = Runoff Coeff.
I = Rainfall Intensity (in/hr)
Brazos County.
I = b / (tc+d)e
tc = Time of concentration (min)
10 years
b = 80
d = 8.5
100 year storm
b = 96
d = 8.0
e = 0.763 e = 0.730
t, = L/(V*60)
L = Length (ft
V = Velocity (ft/sec)
APPENDIX B
Pipe Design Summary
Primrose School College Station
Appendix B
Proposed Storm Sewer Analysis
Pipe Design Summary
Pipe
No.
P1pe
Sae
lint
Length
k
Slope
%
Contributing
Drainage Areas
Aio
Contributing Pipes
cfs
Wo
f s
0,00
cfs
`Aoo
lips)
101
:15
27
0.50
300
197
3.49
2,51
3,80
102
103 '.
8
8
38
48
0.50
0,50
364
305
0.21
P102 0,41
1.95
2.36
028
0.56
2.09
2.54
104
115
40
050
Pi01, P103 2.28
367
307
3.98
WS
15
20
050
306
P104 2.69
3.87
363
4.06
106
15
34
0,50
P105'� 2 69
3.87
3.63
4.08
107
15
52
0.50
_
__P1061 2.69
3.87
363
I 4A8
108
115
12
0,50
400
P107 2 87
3,91
3,86
4.17
109
I15
18
0.50
P108 287
3.91
386
,1
i 4.17
i
110
15
180
050
_-
P109 287
i 391
1. 3.86
4.17
31
0.50
301
1.93
' 3.53
2.61
3.82
202
8
38
0.50
303
021
1 95
028
2.09
203
8
22
0.50
302
P202 0.41
2.36
056
2.54
204
15
23
0.50
i
P203, P201 2.35
3]2
3 17
4.00
205
15
25
,
050
P204 2.35
3.72
3.17
4.00
206
15
22
0.50
_-
__.__"__-
P205 2.35
3]2
_
3.17
- -__...
- 400
207
8
17
0.50
308
0.41
236
0.56
2.54
208
t15
,22
___ 0,50
P206, P2W 2.76
3.89
3]2
4.12
209
i8
17
0.50
309
0.28
2.09
0,37
281
210
115
25
0.50
P208, P209 3.04
3.94
4 t0
4.i8
211
8
17
0.5p
310
0.14
1.70
019
1.87
212
213
15
8
22
8
0.50
O50
- -
311
P210, P211 3.18
i 0.14
401---
1.70
_-4,05
-428
0.19
422��
1.87
214
15
3
---0,50---
P212, P213 3,32-
4.47
421
i
215
15
21
_ 0.50
P214 3.32
4.05
4.47
421
216
:
15
10 1
j 0.50
P215 i 3.32
4.05
447
421
217
18
44
050
"',
P110, P216 + 6.18
4.87
8 33
4.71
218
219
j,.
12
24
40
16
t.00
0.35
I
312
j 307
_ 1.59
P217, P218 9.43
436
480
215
1272
4,73
4.83
APPENDIX C
Inlet Design Summary
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