HomeMy WebLinkAboutDrainage ReportBuena Vida
Drainage Report
REVISED: 09/16/2010 — The pond volume and outlet
structure was revised for each storm event based on
off -site pass through flow routing due to grading changes.
September 16, 2010
Prepared For:
10536, LLC
3608 East 29th Street
Bryan, Texas 77802
Prepared By:
eHOMEYER
ENGINEER ING,INC.
TEIPE REGISTRATION No. F-8440
P.O. Box 294527
Lewisville, TX 75029
Phone: 972-906-9985
Fax: 972-906-9987
"This report for the drainage design of Buena Vida
was prepared 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 for the proposed drainage improvements have
been issiddd"' /
Licensed Prbfessiokal Engineer
O �-
State of Texas
m COF T 'N..........
'• * b
STEVEN R. HOMEYER
1' 86942 woe
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Technical Design Summary Report
Buena Vida
Table of Contents
Executive Summary 1
A. General Location and Description of Project Area 3
B. Drainage Watershed and Study Area 3
C. Drainage Design Criteria 4
D. Drainage System Design 5
Table 1 7
E. Conclusions 8
F. References 8
G. Appendices
I. Exhibits:
A — General Location Map
B — Bee Creek watershed
C— FEMA FIRMETTE
D.1 & D.2 — Existing & Proposed Drainage Area Map for Buena Vida
E.1, E.2, E.3, EA — Storm Plans & Profiles for Buena Vida
F .1, F.2— Detention Plan & Details for Buena Vida
G— Detention & Weir Calculations for Buena Vida
H - Topographic survey conducted by Kling Engineering & Surveying
II. Hydrologic and Hydraulic Computations
Detention area/volume capacity
III. Miscellaneous
Site Plan for Bethel Buena Vida
Grading Plan for Buena Vida
Erosion Control Plan for Buena Vida
H. Technical Design Summary
Drainage Report — Buena Vida September 16, 2010
Executive Summary
Contact Information:
Engineer:
Homeyer Engineering, Inc.
Steven R. Homeyer, P.E., CFM
P.O. Box 294527
Lewisville, Texas 75029
Developer:
10536, LLC
Kassi Horner
3608 East 29th Street, Suite 112
Bryan, Texas 77802
Identification of the proposed project
Buena Vida Subdivision
Proposed 60 lot, 11.67 acre, Single -Family Residential Subdivision.
Project Location
This project is located within the city limits of the City of College Station, on the North side of
Rock Prairie Road, east of Jones -Butler Road and west of Wellborn Road, primarily in the Bee
Creek watershed area. Approximately one acre of the site drains southeast to an unnamed
watershed area per the City of College Station drainage manual.
This property is in a FEMA Zone X, an area determined to be outside the 500-year flood plain.
No portion of this site is located within a Zone A or AE designated flood area.
Hydrologic Characteristics
The existing site consists of grass covered pasture land with a few trees and includes no
buildings. The runoff that crosses this property from off -site comes from 3.24 acres of pasture
land, located southwest of the subject property. This runoff flows overland across the western
half of the site to the northwest corner of the site. Runoff from the site joins flow from the
Williamsgate Subdivision at an existing detention pond in the northwest property corner. The
detention facility outfalls to the northwest and is collected by an existing drainage channel and
conveyed to an unnamed tributary of Bee Creek.
Storm water from 1.0 acre drains off this site generally to the southeast. This runoff is carried
southwest in the bar ditch of Rock Prairie Road to an unnamed watershed area per the City of
College Station drainage manual.
Drainage Report — Buena Vida Subdivision September 16, 2010
Stormwater Management Plan
An existing detention pond is located at the northwest corner of the property and will be
enlarged to accommodate the proposed flows of the development. The existing weir will be
modified to release the existing pre -developed flow. The drainage area was determined using a
topographic survey conducted by Kling Engineering & Surveying.
The Modified Rational method was used to determine the volume of stormwater storage needed
to compensate for increased runoff due to development and 10% was added to the volume per
the City of College Station Unified Stormwater Design Guidelines. The 5, 10, 25, 50 and 100-
year storm events were analyzed for both pre and post developed conditions. With an allowable
release rate of 93.11 cfs, the detention pond volume is required to hold 26,599 cubic feet of
water. The design of the rectangular weir outfall allows the pond to meet each of the design
years' allowable release rates and provides 26,829 cubic feet of storage at the 100-year release
elevation. The added 10% of volume requires the pond to provide a total of 29,511 cubic feet.
At 0.92 feet below the top of wall of the pond, the detention facility provides 29,511 cubic feet of
volume.
Coordination with Other Entities
A Storm Water Pollution Prevention Plan will be submitted to the city and the appropriate TCEQ
permits will be obtained prior to the issuance of a development permit by the city.
Technical Design Summary Report
One 7-page Drainage Report with Appendices dated September 16, 2010 and one set of
preliminary construction drawings (35 sheets) dated September 16, 2010 comprise the drainage
report for this project.
Drainage Report— Buena Vida Subdivision September 16, 2010
A. General Location and Description of Project Area
The Buena Vida development is a proposed 60 lot, 11.67 acre, single-family residential
subdivision. This is a single phase development.
This project is located within the city limits of the City of College Station, on the north side of
Rock Prairie Road, east of Jones -Butler Road and west of Wellborn Road, primarily in the Bee
Creek watershed area. Approximately one acre of the site drains in a southeasterly direction to
an unnamed watershed area per the City of College Station drainage manual. (See Exhibit A)
Properties surrounding the proposed Project Area:
To the southeast: Rock Prairie Road R.O.W.
To the south: Diamond T Storage, LLC., 1.12 Acres, Vol. 6177, Pg. 2135
To the southwest: Charles I & Mary E Turner, 22.97 Acres, Vol. 3331, Pg. 61
To the northwest: L.M. Haupt, Jr., 136.063 Acres, Vol. 171, Pg. 392
To the northeast: Williamsgate Subdivision, 8.60 Acres, Vol. 7705, Pg. 206
As stated above, the majority of this property is in the Bee Creek watershed with approximately
one acre of the site draining in a southeasterly direction to an unnamed watershed area per the
City of College Station drainage manual. This property is located in a FEMA Zone X, an area
determined to be outside the 500-year flood plain. No portion of this site is located within a
Zone A or AE designated flood area. (Exhibits B & C)
Engineer: Developer:
Homeyer Engineering, Inc. 10536, LLC.
Steven R. Homeyer, P.E., CFM Kassi Horner
P.O. Box 294527 3608 East 29th Street, Suite 112
Lewisville, Texas 75029 Bryan, Texas 77802
B. Drainage Watershed and Study Area
The existing site consists of grass and a few trees with no buildings. This site receives off -site
flow from 3.24 acres located southwest of the subject property. This runoff flows overland
across the western half of the site to the northwest corner of the site. Pass -through and on -site
runoff flows join with runoff from the Williamsgate Subdivision in the existing detention facility at
the northwest property corner. The pond outfalls to the northwest neighboring 136 acre tract
and is collected by an existing channel which then conveys the flow to an unnamed tributary of
the Bee Creek. The existing detention pond for the Williamsgate Subdivision — Phase I was
designed by Municipal Development Group. The drainage report was signed and sealed by
Lenwood S. Adams, P.E. and dated June 27, 2005. The subject property also contributes flow
from approximately one acre to the Rock Prairie Road R.O.W. The existing Rock Prairie Road
bar ditch conveys this runoff to the southwest to an unnamed watershed.
At present, 16.97 cfs of runoff enters this site from the off -site southwestern property during the
100-year storm event. Approximately 5.24 cfs of runoff leaves the site to the southeast and to
the Rock Prairie Road R.O.W. Most of the existing on -site drainage, 55.89 cfs, along with the
16.97 cfs of off -site flow, ultimately flows to the northwest corner of the property to join with
36.58 cfs of runoff from the Williamsgate Subdivision at the existing detention pond. Another
17.41 cfs of the Williamsgate Subdivision runoff free flows north to the Barracks Development.
Drainage Report — Buena Vida Subdivision September 16, 2010
As stated above, the detention pond outflows to the existing 136 acre tract owned by L.M.
Haupt, Jr.
During the preliminary plat review process, the City of College Station staff indicated that they
had received numerous complaints from property owners that are located downstream of the
existing Williamsgate Subdivision detention pond. City staff indicated that Homeyer
Engineering, Inc. (HEI) would need to analyze the existing drainage conditions associated with
the development of the Williamsgate Subdivision Phase I and incorporate any necessary
modifications into the design of the Buena Vida drainage improvements.
Upon reviewing the Williamsgate Subdivision construction drawings and the accompanying
drainage report, HEI determined that the combination of the existing free flow from the lots
along the north side of Keefer Loop and the release rate from the existing detention pond
exceeded the pre -developed conditions for the currently developed Williamsgate Subdivision.
This determination was based on the "Post -Development Detention Inflow" chart included in the
drainage report for the Williamsgate Subdivision. This chart and the associated calculations
indicate that the detention pond was designed to capture all of the developed on -site flows from
both the Williamsgate Subdivision Phase I and the proposed Buena Vida subdivision.
As indicated above, approximately 2.8 acres within the existing Williamsgate Subdivision free
flows in a northerly direction and into the Barracks development. As a result, the existing
detention pond outlet structure is oversized and therefore does not regulate the storm flows as
required by the city's development ordinances. As part of the Buena Vida project, the HEI
construction drawings identify proposed modifications to reduce the width of the existing outlet
structure and to increase the size of the detention pond to account for the increase in volume
associated with the decrease in the allowable discharge rate. These proposed modifications will
reduce the total amount of storm water being released onto the downstream properties.
C. Drainage Design Criteria
Pre -Developed:
The subject property, along with the Williamsgate subdivision property, consists of 20.26 acres.
Of this area, 19.26 acres naturally drain to the northwest. Additionally, 3.24 acres of off -site
pasture land pass through the subject property to the north. The Williamsgate Subdivision
drainage report used an existing C-value of 0.49, but based on the City of College Station
Stormwater Design Guidelines, a C-value of 0.45 was determined to be more appropriate based
on the existing site conditions. Using a pre -developed C-value of 0.45 and an intensity of 11.64
in./hr., the pre -developed flow from the areas flowing to the northwest is Q100=117.85 cfs. One
acre of the subject property drains southeast to the Rock Prairie Road R.O.W. This equates to
a pre -developed flow Q,00=5.24 cfs to the R.O.W.
Post -Developed:
The proposed detention pond was designed to accept 127.28 cfs from the subject property
during a 100-year storm event, which includes 13.09 cfs of off -site flow from the southwest and
36.58 cfs of flow from the Williamsgate Subdivision. The remaining flow of 3.88 cfs of off -site
pass -through from the southwest will be free flowed to the north. Of the remaining on -site flow,
4.62 cfs exits to the Rock Prairie Road R.O.W. undetained, while 3.45 cfs free flows to the
northwest property line. Based on existing conditions, 17.41 cfs will continue to free flow to the
north from the Williamsgate Subdivision.
Drainage Report — Buena Vida Subdivision September 16, 2010
The storm water from the subject site will be collected in several on -site curb inlets and one "Y"
inlet and will be piped to the redesigned on -site detention facility. (Exhibits E.1-E.5)
Additionally, some runoff will enter the detention pond via sheet flow. The remainder of the
runoff will be allowed to free flow from the site undetained. The proposed detention facility
outfalls into the existing drainage ditch located to the northwest on the neighboring 136 acre
tract. This drainage ditch flows northwest toward Bee Creek. (See Exhibit D.2 — Proposed
DAM)
The proposed detention facility outlet structure is a rectangular weir. (See Exhibit G) As
designed, Qioo=93.11 cfs will be released from the detention facility in addition to the Q,00=3.45
cfs of free flow to the northwest property line, the Qioo=3.88 cfs of pass -through free flow from
off -site southeast to the northwest property line and the Q100=17.41 cfs currently free flowing
from the Williamsgate Subdivision to the north.
The Modified Rational method was used to determine the volume of stormwater storage
required to compensate for the increased runoff due to the proposed development. In addition,
10% was added to the total volume of the pond in accordance with the City of College Station
Unified Stormwater Design Guidelines. The 5, 10, 25, 50 and 100-year storm events were
analyzed for both pre and post developed conditions. With an allowable release rate of 93.11
cfs, the detention pond volume is required to hold 26,829 cubic feet of water. The design of the
rectangular weir outfall allows the pond to meet each of the design years' allowable release
rates and provides for 29,029 cubic feet of storage at the 100-year release elevation of 306.59.
The added 10% of volume requires the pond to provide at total of 29,511 cubic feet of storage.
At 0.92 feet below the top of pond, the detention facility provides for 29,511 cubic feet of
volume. The top of pond elevation is 307.55. The proposed Detention Plan and Calculation
sheets are included in Exhibits F & G.
The overall drainage area was determined using a topographic survey by Kling Engineering &
Surveying. (Exhibit H). The time of concentration was computed using the formula from the City
of College Station Unified Stormwater Design Guidelines. A time of concentration for pre -
developed flows was calculated as approximately 10 minutes. For post developed flows, a
minimum time of concentration of 10 minutes was used.
Rainfall intensity was computed using the formulas in Table C-1 of the City of College Station
Unified Stormwater Design Guidelines and the times of concentration above. "C" factors were
obtained from Tables C-2 & C-3 of the City of College Station Unified Stormwater Design
Guidelines.
D. Drainage System Design
The proposed pond was designed to accept Q100=127.28 cfs from the subject property,
Williamsgate Subdivision Phase I and the off -site southwestern property. The allowable
discharge from the subject property to the north and west is Q100=117.85 cfs. Based on the
proposed free flow to the north from the subject property and the existing free flow from the
Williamsgate Subdivision (Qloo=20.86 cfs) the proposed pond will discharge Q100=93.11 cfs from
the modified outlet structure proposed as part of this project.
The Rock Prairie Road R.O.W. to the west originally received a Q,00=5.24 cfs from the south
eastern corner of the subject property and is designed to receive Qt00=4.62 cfs after the
development is complete. The Williamsgate Subdivision Phase I will continue to discharge
Drainage Report — Buena Vida Subdivision September 16, 2010
Q100=17.41 cfs of free flow to the north. Area 10 of the Proposed Drainage Area Map identifies
a free flow to the west of Q1oo=3.45 (See Exhibit D.2 — Proposed DAM).
Prior to the development of the Williamsgate Subdivision Phase I and the proposed Buena Vida,
the site generated Q100=117.85 cfs as an undeveloped pasture. (See Exhibit D.1 — Existing
DAM) After the Buena Vida project is completed with the proposed detention pond and outlet
structure modifications, the proposed release rate will be Q100=117.85 cfs based on the
controlled release rate of Q100=93.11 cfs from the detention pond and Q100=24.74 cfs of free flow
from various areas within the development. (See Table 1 for Drainage Summary Totals)
Drainage Report — Buena Vida Subdivision September 16, 2010
Drainage Summary Totals for Buena Vida Subdivision - See Exhibits DA & D.2
JL_j
yr.
5 yr.
10 yr.
25 yr.
50 yr.
I 100 yr.
v .
Area Discharged North from Buena Vida
10.67
10.67
10.67
10.67
10.67
10.67
o
Area Discharged North from Williamsgate
8.59
8.59
8.59
8.59
8.59
8.59
cArea
from Off -site Pass Through to North
3.24
3.24
3.24
3.24
3.24
3.24
0/
Area Discharged Southeast to Rock Prairie Road
a ¢`
from Buena Vida
1.0
1.0
1.0
1.0
1.0
1.0
To ProposedDetention Pond - Areas 1, 2, 3 4, 5, 6,
d
7, 8, 9,11,12, OS1, OS2, OS3, OSS
18.89
18.89
18.89
18.89
18.89
18.89
Free Flow area to Off -site North from Williamsgate `
2.77
2.77
2.77
2.77
2.77
2.77
o. d
Free Flow area to Off -site North from
g
Buena Vida Area 10
0.47
0.47
0.47
0.47
0.47
0.47
Free Flow area to Off -site North from OS4
0.74
0.74
0.74
0.74
0.74
0.74
Free Flow area Southeast to Rock Prairie Road from
a
Buena Vida
0.63
0.63
0.63
0.63
0.63
0.63
Pre Developed 'C' value
0.45
0.45
0.45
0.45
0.45
0.45
Post Developed'C'value (Buena Vida)
0.63
0.63
0.63
0.63
0.63
0.63
Post Developed'C'value (Williamsgate)
0.54
0.54
0.54
0.54
0.54
0.54
Rainfall Intensity (In/Hr)
6.33
7.69
8.63
9.86
11.15
11.64
Discharge Off -site North from Buena Vida
30.39
36.92
41.44
47.34
53.54
55.89
co
Discharge Off -site North from Williamsgate
24.47
29.73
33.36
38.11
43.10
44.99
"a V
z
Discharge from Off -site Pass Through to North
9.23
11.21
12.58
14.38
16.26
16.97
Pre Developed Total
64.09
77.86
87.38
99.83
112.90
117.85
d
a
§'
Discharge Off -site Southeast from Buena Vida
2.85
3.46
3.88
4.44
5.02
5.24
Discharge to pond from Areas 1, 2, 3,'4, 5, 6,
7, 8, 9,!11,12, OS1, OS2, OS3, OSS
69.23
i84.10
94.37
107.83
121.93
127.28
Discharge Off -site North from pond
50.61
61.54
69.08
78.89
89.18
93.11
Discharge (Free Flow)Off-site North from
a
Buena Vida Area 10
1.87
2.28
2.56
2.92
3.30
3.45
ti
Z'
Discharge (Free Flow) Off -site North
I u
from OS4
2.11
2.56
2.87
3.28
3.91
3.88
Discharge (Free Flow) Off -site North from
0
o
Williamsgate
9.47
11.50
12.91
14.75
16.68
17.41
Post Developed Total
64.06
1 77.88
87.42
99.85
112.87
117.85
Discharge Off -site Southeast to Rock Prairie
Road from Buena Vida
2.51
3.05
3.43
3.91
4.43
4.62
Drainage Report- Buena Vida Subdivision September 16, 2010
E. Conclusions
The intent of the Buena Vida Drainage Report is to safeguard life, property and public
infrastructure from damage due to ill -managed storm flow. This report demonstrates
compliance with the Unified Stormwater Design Guidelines and the City of College Station Code
of Ordinances.
The proposed drainage improvements on the subject property will reduce the overall storm
discharge from the subject property to existing levels and will decrease the amount of
undetained storm discharge from the Williamsgate Subdivision Phase I. The proposed detention
pond outfalls directly into an existing drainage channel, which leads to Bee Creek.
F. References
City of College Station Code of Ordinances
Cities of Bryan and College Station Unified Stormwater Design Guidelines - January 2010
Drainage Report - Buena Vida Subdivision September 16, 2010
Technical Design Summary Report
Buena Vida
Appendices
r
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SITE
CATION
Pork
EXHIBIT A
n\AA\
H O M EY E R SCALE: i"=2000 ® VICINITY MAP
ENGINEERING, INC. 0s-16-2010 BUENA VIDA SUBDIVISION
CIVIL ENGINEERING* PLATTING DRAWN BY: CDL CITY OF COLLEGE STATION
SITE & LAND PLANNING BRAZOS COUNTY, TEXAS
P.O. SOX SITE
&l•LE D VILA PLANNING
0'15B29
992-906-9985 PHONE 0992906-9907 VAX CHECKED BY: SRH NORTH
EXHIBIT B
SECTION IX
APPENDIX B — REGION'S WATERSHEDS
4
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6
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9
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Rock Priirin;
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Feet
0 2500 5200 10,400
Figure B-3: Bee Creek Watershed Area
STORMWATER DESIGN GUIDELINES Page 6 of 24 APPENDIX B: REGION'S WATERSHEDS
Effective February 2007 As Revised February 2009
F=XHIE3IT C
ZONE X
APPRO%IMATE SCALE
70 0
NATIONAL FLOOD INSURANCE
FIRM
FLOOD INSURANCE RATE MAP
BRAZOSCOUNTY,
TEXAS AND
INCORPORATED AREAS
PANEL 182 OF 250
lY" us"', V.nNW Yw,
^rn 0 �1 .Mn W LOYMUkm NUaem ,Yin
Brazos Count Nm WYYnMa F`..q}nWYYFa FO
n�.
Unincorporated MAP NUMBER
481195 40041 COI 02 C
EFFECTIVE DATE:
lemum IULY 2, 1992
Federal Emergency Management Agency
nis is an choice cop/ or a Pemon or me aame rerereneeo need map. Ii
was en er.ted using F-MIT On -Line. This map does not reflect changes
or amendments whlch may have been made subsequent to the date on the
time dock. For the latest product Information about National Flood Insurance
Program flood maps check the FEMA Flood Map Store el w+.w. mm ec.fa a.gov
DRAINAGE AREA NOT
1. THE TOPOGRAPHIC INFORMATION FOR THE
OFF SITE DRAINAGE AREAS WAS OBTAINED
FROM THE CITY OF COLLEGE STATION.
2. THE DRAINAGE AREAS FOR WILLIAMSGATE
SUBDIVISION PHASE 1 ARE BASED ON THE
GRADING AND DRAINAGE PLANS FOR
WILLIAMSGATE PHASE 1 AS PREPARED BY
MUNICIPAL DEVELOPMENT GROUP AND
DATED JANUARY 3, 2006
LEGEND
A DRAINAGE AREA NUMBER
0 0100 EXISTING
DRAINAGE AREA LIMITS
--xxx-- EXISTING CONTOURS
-xxx- PROPOSED CONTOURS
-► DIRECTION OF STORMWATER FLOW
\t�
00 200
L�
PRE -DEVELOPED DRAINAGE CALCULATIONS PRIOR TO WILLIAMSGATE PHASE I
DRAINAGE
AREA
AREA
ACRES
C
I
Tc
(min)
"1-2•
(in/hr)
"Q-2"
(cfs)
"1-5"
(in/hr)
"Q-5'
(cfs)
"1-10"
(in/hr)
"0-10"
(cfs)
"1-25"
(in/hr)
"Q-25•
(cfs)
"1-50"
(in/hr)
'Q-50"
(cfs)
'1-100"
(in/hr)
"Q-100"
(cfs)
COMMENTS
1
10.67
0.45
10
6.33
30.39
7.69
36.92
8.63
41.44
9.86
47.34
11.15
53.54
11.64
55.89
TO OFF -SITE NORTH
2
1.00
0.45
10
6.33
2.85
7.69
3.46
8.63
3.88
9.86
4.44
11.15
5.02
11.64
5.24
TO ROCK PRAIRIE ROAD
OSl
3.24
0.45
10
6.33
9.23
7.69
11.21
8.63
12.58
9.86
14.38
11.15
16.26
1T64
16.97
TO ON -SITE AREA 1
OS2
6:82-1
0.45
10
6.33
16.58
7.69
20.14
8.63
22.60
9.86
25.82
11.15
29.20
11.64
30.49
TO OFF -SITE NORTH
OS3
2.77
0.45
10
6.33
7.89
7.69
9,59
8.63
10.76
9.86
12.29
11.75
13.90
11.64
14.51
TO OFF -SITE EAST
TOTAL
23.50
66.94
81.32
91.26
104.27
117.91
123.09
EXISTING DRAINAGE CALCULATIONS
DRAINAGE
AREA
AREA
ACRES
C
Tc
(min)
"1-2,
(in/hr)
"0-2"
(cfs)
"1-5"
(in/hr)
"0-5"
(cfs)
"1-10"
(in/hr)
"0-10-
(cfs)
1-25"
(in/hr)
"0-25-
(cfs)
1-50"
(in/hr)
"Q-50"
(cfs)
"1-100"
(in/hr)
"Q-100"
(cfs)
COMMENTS
1
10.67
0.45
10
6.33
30.39
7.69
36.92
8.63
41.44
9.86
47.34
11.15
53.54
11.64
55.89
TO OFF -SITE NORTH
2
1.00
0.45
10
6.33
2.85
7.69
3.46
8.63
3.88
9.86
4.44
11.15
5.02
11.64
5.24
TO ROCK PRAIRIE ROAD
051
3.24
0.45
10
6.33
9.23
7.69
11.21
8.63
12.58
9.86
14.38
11.15
16.26
11.64
16.97
TO ON -SITE AREA 1
OS2
5.82
0.54
10
6.33
19.89
7.69
24.17
8.63
27.12
9.86
30.99
11.15
35.04
11.64
36.58
TO EXISTING DETENTION
OS3
2.77
0.45
10
6.33
7.89
7.69
9.59
8.63
10.76
9.86
12.29
11.15
13.90
11.64
14.51
TO OFF -SITE EAST
TOTAL
23.50
70.26
85.35
95.78
109.43
123.75
129.19
PROPOSED DRAINAGE CALCULATIONS
DRAINAGE
ACRES
C
(min)
(in/hr)
,(cfs"
"I-5
(in/hr)
'Q-5
(cfs)
"1-10
(in/hr)
"Q-10"
(cfs)
"1-25'
(in/hr)
0-25
(cfs)
"I-50"
(tn/hr)
"Q-50"
(cfs)
"I-100"
(in/hr)
"0-100"
(cfs)
COMMENTS
1
1.42
0.63
10
6.33
5.66
7.69
6.88
8.63
7.72
9,86
8.82
11.15
9.97
11.64
10.41
TO PROP. 10' CURB INLET
2
0.83
0.63
10
6.33
3.31
7,69
4.02
8.63
4.51
9.86
5.15
11.15
5.83
11.64
6.09
TO PROP. 10' CURB INLET
3
1.37
0.63
10
6.33
5.46
7.69
6.64
8.63
7.45
9.86
8.51
11.15
9.62
1L64
10.04
TO PROP. 10' CURB INLET
4
0.98
0.63
10
6.33
3.91
7.69
4.75
8.63
5.33
9.86
6.09
11.15
6.BB
11.64
7.18
TO PROP. 10' CURB INLET
5
0.35
0.63
10
6.33
1.40
7.69
1.70
8.63
1.90
9.86
2.17
11.15
2.46
11.64
2.57
TO PROP. 10' CURB INLET
6
0.94
0.63
10
6.33
3.75
7.69
4.55
8.63
5.11
9.86
5.84
11.15
5.60
11.64
6.89
TO PROP. 10' CURB INLET
7
1.83
0.63
10
6.33
7.30
7.69
8.87
8.63
9.95
9.86
11.37
11.15
12.85
11.64
13.42
TO PROP. 10' CURB INLET
8
1.08
0.63
10
5.33
4.31
7.69
5.23
8.63
5.87
9.86
6.71
11.15
7.59
11.64
7,92
TO PROP. 10' CURB INLET
9
0.81
0.63
10
6.33
3.23
7.69
3.92
8.63
4.40
9.86
5.03
11.15
5.69
11.64
5.94
TO PROP. 4'x4' DROP INLET
10
0.47
0.63
10
6.33
1.87
7.69
2.28
8.63
2.56
9.86
2.92
11.15
3.30
/1.64
3.45
TO OFF -SITE PROPERTY
11
0.87
0.63
10
6.33
3.47
7.69
4.21
8.63
4.73
9.86
5.40
11.15
6.11
11.64
6.38
TO PROP. 10' CURB INLET
12
0.19
0.63
10
6.33
0.76
7.69
0.92
8.63
1.03
9.86
1.18
11.15
1.33
11.64
1.39
TO DETENTION FACILITY
13
0.63
0.63
10
6.33
2.51
7.69
3.05
8.63
3.43
9.86
3.91
11.15
4.43
11.64
4.62
TO ROCK PRAIRIE ROAD
OSI
0.36
0.45
10
6.33
1.03
7.69
1.25
8.63
1.40
9.86
1.60
11.15
1.81
11.64
1.89
TO ON -SITE AREA y1
OS2
1.68
0.45
10
6.33
4.79
7.69
5.81
8.63
6.52
9.86
7.45
11.15
8.43
11.64
8.80
TO ON -SITE AREA #2
OS3
0.46
0.45
10
6.33
1 1.31
7.69
1.59
8.63
1.79
9.86
2.04
11.15
2.31
11.64
2.41
TO ON -SITE AREA M3
OS4
0.74
0.45
10
6.33
2.11
7.69
2.56
8.63
2.87
9.8fi
3.28
11.75
3.71
11.64
3.88
TO OFF -SITE PROPERTY
OSS
5.72
0.54
10
6.33
19.55
7.69
23.75
8.63
26.66
9.86
30.46
11,15
34.44
77.64
35.95
WILLIAMSGATE DRAINAGE
OS6
2.77
0.54
10
6.33
9.47
7.69
11.50
8.63
12.91
9.86
14.75
11.15
16.68
14.64
IT41
TO OFF -SITE PROPERTY
TOTAL
23.50
1 103.49 1
116.14
1
132.69
150.05
156.64
J
EXISTING DRAINAGE AREA MAP
THE CONTRACTOR SHALL CONTACT
DIG-TESS AT 1-800-344-8377 A
MINIMUM OF 48 HOURS PRIOR TO THE
COMMENCEMENT OF ANY
CONSTRUCTION ACTIVITIES t
EXHIBIT [:)_l
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE J/ 86942
DATE: 09/16/2010
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EXHIBIT [D.2
LEGEND
DRAINAGE AREA NUMBER
O 0100 PROPOSED
DRAINAGE AREA LIMITS
xxx-- EXISTING CONTOURS
—xxx— PROPOSED CONTOURS
�y DIRECTION OF STORMWATER FLOW
ITHE CONTRACTOR SHALL CONTACTN
OIG-TESS AT 1-800-344-8377 A
MINIMUM OF 48 HOURS PRIOR TO THE
COMMENCEMENT OF ANY
M1 CONSTRUCTION ACPW77ES /
l
DRAINAGE AREA NOTES:
1. THE TOPOGRAPHIC INFORMATION FOR THE
OFF -SITE DRAINAGE AREAS WAS OBTAINED
FROM THE CITY OF COLLEGE STATION.
2. THE DRAINAGE AREAS FOR WILLIAMSGATE
SUBDIVISION PHASE 1 ARE BASED ON THE
GRADING AND DRAINAGE PLANS FOR
WILLIAMSGATE PHASE I AS PREPARED BY
MUNICIPAL DEVELOPMENT GROUP AND
DATED JANUARY 3, 2006.
3. REFER TO THE EXISTING DRAINAGE AREA
MAP, SHEET C5, FOR THE PROPOSED
DRAINAGE AREA CALCULATIONS.
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE q 86942
` DATE: 09/16/2010
m
N
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DATE: 11/16/09
HEI x: 09-119
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APPRORO X. 10
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31'
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PROP 131 LF OF "'---"
2] CL III RCP -
0 1.20% 5LOPE
+--•-
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6 4. N 0
_
F
STORM LINE A STA 0+00 TO 6+24
SCALP
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co
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SCALE:
a2•0
II n
DIA 30" RCP
i - _
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- N 1"=4a
xu
_.
__
Qo 37.18 CF5
II
--
-- ---
- V=7.42 FPS
L-.
xx
Sf=0.7B5%
Q,A 33 43 8i" RCA
Q,A 46"v 43 3'i" RCA
1
-
-5
-04� 59.33 CFS -
-
5
04p-53.59 CFS
--
- -
-
---
-
_.
-
CF5 _
53.59 Cf5
V B39 FPS
V=8.39 FP
Vu7
V 7.6 FPS
PROPOSED PILL SMALL BE
� PROPOSED
-
KEEFER LOOP
Sf 0.787% -
Sf 0.625%
-
- -
PROPOSED
COMPACTED TO MIN 95%
1
-
1_ GROUN
STD PROCTOR DENSITY
-
- J -
PROPOSED CULLEN TRAIL
EXISTING GROUND_
- -
PROPOSED DILL SMALL BE
- -_ -
-..-.-
-.
-_ - -
COMPACTED TO MIN 95X.
--___ -..
-_
__ ...
_._ _L..
__.___
7-
_. -.
SiD PROCTOR DENSitt
_ __.
PROPOSED GROUND
-
- _..
_ _
EXISTNG GROUND
I -_ -
_. - __ _ _ -„
_
_-. -
___ __.L.�
_- _- - -
1
I
I
-47
PROP. B" WL_.._.
-
LF OF 26 467x43
CL III RCA PIPE
260 LF
OF 26 36"a43 3"
-
__
.. 1......
217 LF OF 30" CL III RCP
O OJO% SLOPE
CL III RCA PIPE
6 0.55% SLOPE
0 0.70% SLOPE
- -
Lx..
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no
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1O�(�JJ
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N��F
LL
N��K�LL
1+00
2+00 3+00
NOTES:
1. TRENCH BACKFILL SHALL BE INSTALLED
PER CITY DETAIL D3-02 ON SHEET C22.
4+00
5+00
320
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE p 86942
DATE: 08/30/2010
_ J
DRAWN: HEI
DATE: 11/16/09
HEI #: 09-119
@C RRU M D0°
@M
' THE CONTRAC
DIG- TESS AT
MINIMUM OF 48
32E
32(
315
310
RIM=314.79`
FL(NW)-30B.58'"\ �
FL(SE)=308.86
J y
I �
I`
� I
I
ifs
STORM LINE A STA 5+24 TO 9+33
EXHIBIT E_2
N
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II �I II h
Z11Qm pa
S
di A
•ZHDZ
19ZWhW
320-• li
14
RI
,/(_i 0 20 90
OT'28
I9 I. FI
/ LOT 29
Z A, pZ
w�-NyQm.i9
ZY
N
-
f
01
If {.-91
�WNJ=W
a>>
WWp W
If :
STA 9+02 LINE 'A'
f.0 -INSTALL INLET A4
at-10' CURB INLET
ol
Z N mO
Y Y m Z
0'
t
- TOP=319.00
6 L. N b
_
- ` _ -_-
. + -
's`'
FL(NW)=314.30 ' _
L(SW)=314.57 '�
=
Z W p m
.
W 1- D
STA 9+33 LINE 'A"
—321-;NSTALL INLET A5 _321
.1-10' CURB INLET
TOP=319.00
FL(NE)=314.99
r
0T1 LOT
I
I I I
I I
SCALE:
_
_._ __
_... -
_. _
na
mm
SCALE:
H. 1'=20 �N...
6d
-___
• _ _.
_.
N Y=4
zi
si.
_
DIA 2]' RCP
-
_..
DIA=24` RCP
OIA 1B' kCP
Olm 36.43 CFS _ _.
-. _
0 m 19.12 CFS - .
-
... _
0 m 12.22 CFS _
-
- Q<.a=37.18 CFS -- -
-- -
- -
- - --
6a 28. 9 CFS -
- - -.
-
Ocw=12.47 CFS
V 9.16 FPS
V 6.09 FPS PROPOSED F
L SHALL BE
1
V 6.92 FPS
- Sf-1.376R PROPOSED FILL
SHALL BE -
--- --
-- -
Sf=0.710R COMPACTED
TO MIN 95% -
-- -
SI 1.347R
-
_-_ COMPACTED TO
MIN 95R -
I _.... ____.
_.. _. __
_ UP PROCTOR_
DENSLTY --
STD PROCTO
DENSITY
--- _-- --- -
PROPOSED KEEFER LOOP-,
--_-_
KEEFER LOOP
PROPOSED OR
LINE
PROPOSED
GROUN EXI
BAD GROUND
EXIS
-
`_
-
--
—II
-
131 if Of 27` CL
III RCP
247 LF OF 24" CL iii RCP
31 LF
OF 18"
0 1.20% SLOP.
0 1.38% SLOPECL
GOP
III
x
_.
n
_
_
_.
B 120R
SLOPE
z
ra
¢�aoll
3
w�Im VI
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E,
�v~iS �QC2 �LLNil$
l-3
5+24 6+00 7+00 8+00
NOTES:
1. TRENCH BACKTILL SHALL BE INSTALLED
PER CITY DETAIL D3-02 ON SHEET C22.
9+00
325
320
315
310
1
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE # 86942
DATE: 0613012010 J
8
QdG°%
Boa
o CYR1
gd c-
B'J
b
t
DRAWN: HET
DATE: 11/16/09
HE[ A: 09-119
X THE CONTRACTOR SHALL CONTACT \
DIG-TESS AT 1-800-344-8377 A
MINIMUM OF 48 HOURS PRIOR TO THE
COMMENCEMENT OF ANY
CONSTRUCTION ACTINTIES 11
STA 0+LINE "LAT A I" IN
n INSTALL: INLET A3
I-10' CURB INLET
a TOP 318 30
FL310.
- FL(SSE)E) 310 98 9B I
FL(SW) 311.20 I
—� _ _ 1
_
- -/ - - -
-r 0
i
- ROP 131 LF OF v
-- --5' 27CL III RCP - -- -
- _ O SLOPE
"-- _ -
1-4' SO. STORM MR-
RIM-314.79
FL(NW)-308.SB
.. i R(SE)=30B.B8„
315
310
30`
-,,
7 I I I
`PROP 31 LF Ior
r21 CL III RCP—
+ -0 D 0 $ OPE _
40
STA WEi A-1 INSTALL 1LINE 'I INLET pgAT A1` 'd INSTALL
\ I 1-10' CURB INLET - ! TYPE "S" HEADWALL -
\ TOP-316.30 \ I I FFL(NE) -311.23 E®6:1 SLOPE
X-----' (SE SHEET 28 INSTALL
\\ FOR DETAILS) 4 LF OF 24" CL III RCP - \ 1-TYPE "S" HEADWALL -, - — - FL=320 53
n \ •. _ ... 32 .._ ® 6:1 SLOPE
I
\I i ---� -----� '--- -- - - - (SEE SHEET C28
I 321 - - - _ r 1. FOR DETAIL)
.322' - \ FL=320.66
323-_; ,..__...+, ..322
---« r.-- 323
—i -
/
t
/ I
STORM LINE "LAT A-1"
SCALE:
mS
SCALE:
OIA=21' RCP H 1'=10'
V. I'-4' 4'
° - ^
^ -
0 CFS
-_ zz
V 6.19 FPS
Sf-O.B78R
1
FILL SHALL BE _
COMPPAACTECTE
COMD TO MIN 95%
-
--- - --STD PROCTOR DENSITY -----
FOPOSED GROUND
EXISTING GROUND
I
31 LF OF 21' CL III RCP
O 0 OR SLOPE
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0+50
315
NOTES:
1. TRENCH BACKfILL S=INSTALLED
310
305
1+00
EXHIBIT E_3
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE y 86942
DATE. 0813012010
DRAWN: HEI
DATE: 11/16/09
HEI a: 09-119
MEW H@ o
(m 9A
THE CONTRACTOR SHALL CONTACT
DIG-iE55 AT 1-800-344-8377 A
- ------ -
MINIMUM Of 48 HOURS PRIOR TO THE
COMMENCEMENT OF ANY
CONSTRUCTION ACTIVITIES
I t I i
I
RI
I_
.E.SL� STA 0+84 LINE 'B"
INSTALL: SOMH III
-
F7 7 I-5• SO. STORM MIN
I RIM 30
56 LF OF
VI r ` FL(N)=305..72
30 CL III RCP
O 0.65% SLOPE
>T �
„ r
till -
STA�ACL'"'
3i 0
rr/1 26 36%43 i'i % 45 WYE
1I tt 305]OI
Fd-i: (IF
I
/ )pe
.'PRbP
26 I'% 43 >)' CL III RCA
O B50R SLOPE
U2'
I I I LOT I
I
_I " - PROP031
L---- ---_
ST 0+ 1 IN %4T B- 2'
T2r-� INSTALL: IN
B
1-10' CURB INLET
STA 0+20 LINE 'lAT BI 1 TOP=311.2] I
NSTALL: INLET B2 FL(W) =30].51
I-5' So. GRATE INLET W/ LO€L{SE)=3071.56
E.31W GRATE MODEL #V566B PROP 41 LF OF
TOP 309.0D 24- CL III RCP
FL(W) =306+44 ---_0 Q.LOPE
I'\
a`
-1 z
v• I- -o zD 40
I
•i i.,) STA 0+11 LINE' AT B 4
_ .. INSTALL: INLET B2 \,
q t-10• CURB INLET ! L(
fd TOP=311.27 _I
,y( H. (NE) -30772
'+ P8'CL ill RO 5 L F•� \ 312 ----
RCP
u O LOOR SLOPE 1311
"A. 4' SO. STORM MH
TOP-3 69
�30
R(NE)09.58 =306.09
--q.
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•
1
I
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) =3 .11
_ \
•'i ST
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-lu m
u _w._.. -
FL(E
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1
0+00 LINE -LAT B-2
--- -2
INSTALL:
T
r
1p1plp'���STA
INSTALL 8
1 RM
\
II
l
PIPE
(( I fr
1
1 I
FL(NE)
IFL=305
_
_ _ _
I
.. -
•
(
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•
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I1
fl
LOT }
10T 2
I
LOT
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I
LOT I1i
it
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Id 1
1
I I
I I;1
it 11
STORM LINE "B"
320
315
1310
i 305
jT i
LO'
SCALE N
__
m�
SCALE:
N 1' 20' o
o'�o�
o
__
oo
��
H 1•-20
1
I
Y B
Y
II
II
Y
Y
nn-
p
II
f _. y 1 4
Ell-
f
DIA=26 95'x 4J �' RCA
DIA=30" RCP
DIA=30' RCP
DIA=18" RCP
-
O1m=34.47 CFS
- -
I
Oloo=14.4] CFS '.
_
- 0 m=28.53 CFS -
_
Oloo=].19 CFS
_
-
Oc,"=51.09 CF5
-
Qav=J5.02 CFS -
- Oms=31.42 CFS - -
Ocu=fl.]B CFS
-
-
V 4.88 FPS
I
V=7.02 FPS
V=5.81 FPS
V=4.0] FPS
-
Sf 0.266R
-- --
_
Sf=0J02R
_ _ - _
- Sf-0.481R
-- Sf=OA66R
PROPOSED FILL
SHALL BE -
PROPOSED SELECT FILL
TRAIL-
PROPOSED CULLEN TRAIL
PROPOSED GROUN
COMPACTED
TO MIN 95%__SHALL
BENEATH 1111S ROAD SECTION
HAVE A PI LESS THAN
E%ISRNG GROUND
1
STD PROC
OR DENSITY
OR EQUAL TO 12
--.
PROPOSED
GROUN
PROPOSED KEEPER LOOP
- ---
_
- _
-- --
I.
EXISRNG
CftOUND
84 LF OF 26
CL III AI
x43
56 LF OF 30" CL III RCP
123 LF OF 30'
CL III RCP
57 LF OF 10' CL
III RCP
O O.SOR SLOPE
O 0.65% SLOPE
O 0.50%
SLOPE
O I OOR SLOPE
mS
A,/"PROP
B.
WL
I
•- z - •
R
it
it m
zm
m
2QOm
m
N
O _IZ
-.j
JZ�0
�w�
3mi�rc1m°
rY
gF
90
O7
o
n�o
^
do�
ea"
zn
FZNLL..-FZ
m
'I�Z.`m( F
m_.-K Gi mm-
FZ'�2vw
K1i C:G
-I.
FFi
mil-•-K(iG
1�z"I
V1-
OFLL
0+00 1+00 2+00 3+00
NOTES:
1. TRENCH BACKFILL SHALL BE INSTALLED
PER CITY DETAIL D3-02 ON SHEET C22,
320 315
315 310
310 30•
305 30C
320
315
30
305
EXHIBIT E_4 N
�
OtIx
Ua�
Zmm
STORM LINE "LAT B-1" ma
9.W
SCALE• ''
NS
SCALE.
H: I 20' n
�o
N 1' 20'
DIA=IB RCP
_
Qmo 594 CFS
- -_
-
0, a 05 CFS
- --
V•336 FPS
Sf=,0318R
PROPOSED
GROUND
EXISRNC
GROUND
tj
20 LF OF 1W CL III RCP
O 0 50R SLOPE
_ PROP 6' SS
FL 304.50 II
- Smmf-
zwzZ
-
o�P'~^mnno..
zopmPn
II
OO
O A n a
.+-qml am3wll; _
_dae-d
31
zm�Cit_.d
0+00
0+50
STORM LINE "LAT B-2"
O•
OW
�ZFOm
Z
�zWNW
_Z�JnZ
HQ
320 W>P-
F
itI--WZ
Z.
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ZW
WW1.aW
O:Nmi
315 Z Ioga
It I
ul
06LOOZ
%m
ZammN
310 T W l- O m
0.
305
SCALE
_
n
m
m n SCALE
DIA=24' RCPH'
I' 20'
Olm 21.34 CFS
1-=4
�_.
Oar=2L92 CFS
V=6]9 FPS
it
32
-- Sf=0885R
I - --
I DIA-21' RCP I
SHALL BE Qlm=13.42 CFS5
CF
PROPOSED
GROUND _ .PROPOSED FILL
COMPACTED TO
MIN 959 V-558FPS
V=5 P
EXISDNC
--- -STD PROCTOR
GROUND
DENSITY _
5f=0.713R
_
_PROP 4'--as
FL-305.50
PROP. 8' WL
41 LF OF 24' CL III RCP I�J�L30
I
LF OF 21' CL
III RCP
O 0 80% SLOPE
0 0.65% SLOPE
m
W
m
z
wms gmr
-�
z9
I
m
gm�
d
vni•m -s-
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'
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Y;N OFo
li
m
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Kri riLL I~/I
o�FO li ri m21�..
0+
1+00
315
l
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE # 86942
DATE: 08/30/2010
J
P
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9@
Q3�"7apy
9p��&
QQ �
73��3 d0
❑ 0
O O
O
DRAWN: HEI
DATE: 11/16/09
NET #: 09-119
NOTES:
1. THE DETENTION POND WILL BE PRIVATELY
OWNED AND MAINTAINED BY THE MLUAMSGATE
SUBDIVISION HOMEOWNER'S ASSOCIATION.
2. THE EXISTING OUTLET STRUCTURE WILL BE
MODIFIED AS PART OF THIS PROJECT. SEE
SHEET C12.1 FOR DETAILS.
3. THE EXISTING DETENTION POND WALL HEIGHT
SHALL BE INCREASED BY INSTALLING A
6"x10"x10" CONCRETE BLOCK CAP WITH
MORTAR ON TOP OF THE DETENTION POND
WALL
4. THE CONTRACTOR SHALL REMOVE AND DISPOSE
OF ALL EXISTING ROCK RIP RAP WITHIN THE
LIMITS OF THE EXISTING DETENTION FACILITY
PRIOR TO THE COMMENCEMENT OF GRADING
ACTIVITIES.
5. THE CONTRACTOR SHALL INSTALL A SLATE
VENEER AS SELECTED BY NE OWNER ON BOTH
FACES OF THE PROPOSED CONCRETE WALL
PROP.
PROP.
EXISTING CONCRETE
APRON TO REMAIN .p
" •�,/ PROP. TW=
EX. TW=
THE TO
P \ 1NTHIN
Ex iP=3pn iE-...El r (TOP
PROP. TW= 307.55 1\ EMERGE
X. Fw=3ozoo EX
EXISTING OUTLET
STRUCTURE TO
REMAIN
`\
305
r ( -
1
PROPOSED
DETENTION POND
100-YR W.S.E.= 306.59
S♦ do R
>� PROPOSED 4' 'N \,
CONCRETE FLUME \
O O.SOR SLOPE I j +
(SEE DETAIL
THIS SHEET) h
♦
m
�X
LEGEND
I.R.F. IRON ROD FOUND
IRS IRON ROD SET
X' CUT X IN CONCRETE
F.C.P. FENCE CORNER POST
ASPHALT
QT TELEPHONE MANHOLE
Tit POWER POLE
{k LIGHT POLE
WATER VALVE
O55NR SANITARY SEWER MANHOLE'
FIRE HYDRANT
0w WATER METER
EXISTING
/��i 0 U
1E EXISTING OUTLET STRUCTURE
ITS OF THE DETENTION FACILITY
SHALL FUNCTION AS THE
IERFLOW OUTLET.
USE CAUTION
O\14'
\ \
rat\R�
AROUND EXISTING
SEWER LINE
PROP. TW= 107.55
PROP. IOU= ]07.5
=d06.50 . +8
'h of// �\ \ PROP. TW--30 ]07.55
REMOVE EX. FLUME
I AND REPLACE WITH
4' CONCRETE FLUME II \��\.
O 0.50% SLOPE
TP=30TS5
(SEE DETAIL I ,
i THIS SHEET) I
I
1 i
TP=304.81
\, PN. Rim=S17 Sl
\
1
V
-EA TPi305.DD 1 I /e\�_
'HEADWALL 305
TO REMAIN
EXISTING HEADWALL
TOP=308.25
FL=305.00
100-YR WSE=306.59
THE CONTRACTOR SHALL CONTACT
\ DIG-TESS AT 1-800-344-8377 A
` MINIMUM OF 48 HOURS PRIOR TO
THE COMMENCEMENT OF ANY
\ CONSTRUCTION ACTIVITIES
\
4-
EXISTING OUTLET
STRUCTURE
TOP=306.92
US FL=304.37
DS FL=304.26
4'
FLUME
SLOPE
WO
SECTION A —A
DETENTION FACILITY SECTION
NOT TO SCALE
PROPOSED DETENTION WALL
-TOP
OF CONCRETE BLOCK=307.55
N W / TOP OF WALL=307.00
1--VARIE00-YR WSE=306.59
I r
SEE RETAINING WALL DETAIL
e" PROPOSED ON SHEET C12.1
V�SLOPE � -:� WALL
SLOPE
SECTION B—B
PROPOSED WALL
NOT TO SCALE
PROPOSED DETENTION WALL
TOP OF CONCRETE BLOCK=307.55
TOP OF WALL-307.00
W
MIN. 6"(H)x1O"(W)xl8"(L) CONCRETE
1'
BLOCK CAP MORTARED ON TOP OF
a
EXISTING DETENTION WALL
100-YR WSE=306.59
.� I
VARIES --I
EXISTING
DETENTION
WALL
SLOPE
SLOPE
S
VARIES
I I I
�r 771
I i
III 11 ��'�i
V I ,�11 Il1
SECTION C C
EXISTING WALL
NOT TO SCALE
DAYS / CONC. O 28
z DAYS W/BARS
- 12' O.C. E.W.. 0
a
4'
PROPOSED 4' CONC FLUME
NOT TO SCALE
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE j( 86942
DATE: 09/16/2010
a (�4
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4 m PW
W-off 19
=ZOO
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DRAWN: HEI
DATE: 11/16/09
HE] *: 09-119
M[Effy A@Q
(MTS
PROP. CONCRETE
BLOCK CAP
,
A d \ \�
/-� END BLOCKCAP
`<
PROP. CONCRETE ,,.
BLOCK CAP l .\4
• a% 9
a
1 _I a
,
l `J
A
I I
1 I
f I �
I 1 �
I O p I
I I
o®
SCALE: 1"=5'
EXISTING WEIR OPENING
— 46'-10 i'•"—
EX. EL= 306.92 4-2 34•"4-2 31.7 EX. EL= 306.92
F - EL= 306.60 EL= 306.60 F -
ALL WALLS 1 1
N4 BARS 0
12" O.C.E.W. I I
1 8'-5 W. I
=4 ==4
I
4000 PSI CONC. 0 28
DAYS W/ #4 BARS 0
12" O.C.E.W.
OUTLET STRUCTURE SECTION A —A
NOT TO SCALE
3/4" CHAMFER
BOTH SIDES
fEC
CONTRACTOR SHAL4
BARS 0
INSTALL A SLAT2"
O.C.E W.
VENEER ABOTH
MATS)
SELECTED BY TH
OWNER ON BOTH
FACES OF THE
PROPOSED
INSTALL KEYWAY
CONCRETE WALL.
FOR PERMISSIBLE
CONSTRUCTION JOINT
N
p4 BARS 0
12" O.C.E.W.
12"
12" (BOTH MATS)
m •
NOTE:
1. PROVIDE VERTICAL EXPANSION JOINT IN WALL AT 25'
MAX SPACING.
2. REINFORCING STEEL SHALL BE GRADE 60
3. ALL CONCRETE SHALL HAVE
A COMPRESSIVE STRENGTH
OF 4000 PSI AT 28 DAYS
RETAINING
WALL DETAIL
NOT TO SCALE
1
EXISTING WEIR WALL
�3
EL- 306.92
-- - -----
EL= 306.60
4
°-
.CONTRACTOR SHALL
ALL WALLS
'DOWEL & EPDXY M4 K
#4 BARS 0 12"
24" SMOOTH BARS ON
O.C.E.W.
° 12" CENTERS ALONG
q"^ ALL EXISTING TO
FL= 304.39
PROPOSED CONCRETE
1
°JOINTS
FL=_ 304.37
FF-
INSTALL KEYWAY
FOR PERMISSIBLE
CONSTRUCTION JOINT
8
4000 PISI CONC. 0 28
DAYS W/ #4 BARS 0
12" O.C.E.W.
OUTLET STRUCTURE SECTION B—B
NOT TO SCALE
Y2- SEALED
EXPANSION JOINT
PROPOSED
EXISTING
WALL
WALL
q5 : 24"
SMOOTH BARS 0
8" CENTERS
4..
1
• T
b
2"—�—
RETAINING WALL CONNECTION
DETAIL
NOT TO SCALE
SCALE: 1"=20'
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE # 86942
DATE: 09/16/2010
P
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CBJ
I
DRAWN: HEI
DATE: 11/16/09
HEI It: 09-119
cCiri'i IE(s� (r IOD o
@I SA
vic average value of the discharge coefficient is
0.li3,The. discharge from a Cipoletti weir is given by
1r1
l;ry.
Q = 1.86bH3/2 [SI] 19.57(a)
Q = 3.367bH3/2 [U.S.] 19.57(b)
Figure 19.9 Trapezoidal Weir
17. BROAD -CRESTED WEIRS
AND SPILLWAYS
.._................................
Host weirs used for flow measurement are sharp -crested.
Ilmvever, the flow over spillways, broad -crested weirs,
dud similar features can be calculated from Eq. 19.49
even though flow measurement is not the primary func-
hoe of the feature. (A weir is broad -crested if the weir
d it luiess is greater than half of the head, H.)
A spillwal{ (overflow spillway) is designed for a capacity
based on the clam's inflow hydrograph, turbine capac-
ity, ;in([ storage capacity. Spillways frequently have a
cross section known as an ogee, which closely approxi-
mntes the underside of a nappe from a sharp -crested
weir. This cross section minimizes the cavitation that
is likely to occur if the water surface breaks contact with
the spillway due to upstream heads that are higher than
designed fors
Discharge from an overflow spillway is derived in the
some manner as for a weir. Equation 19.58 can be used
for broad -crested weirs (Cl = 0.5 to 0.57) and ogee spill-
ways (Ci = 0.60 to 0.75).
Q = s Crb�H3/2 19.58
fbc I{,,,.trrrr, equation (Eq. 19.59) for broad -crested weirs
combines all of the coefficients into a spillway (weir)
co°lih ient and adds the velocity of approach to the up -
It""" head. The Hot -ton coefficient, CHortom is specific
In the Morton equation.
/ yg l 3/2
Q = CHortonb I H -F- I 19.59
9
If the velocity of approach is insignificant, the discharge
s
Q = C,bH3/2 19.60
t(Sn itatieand separation will normally not occur as long as the
nrh,nl s i H is l ll;� ('A"sess than twice the design value. The shape of
pillway will be a function of the design head.
OPEN CHANNEL FLOW 19-13
Cs is a spillway coefficient, which varies from about
3.3 to 3.98 ft0•5/sec (1.8 to 2.2 m0-6/s) for ogee spill-
ways. 3.97 ft°-s/sec (2.2 mo•s/s) is frequently used for
first approximations. (Notice that C. and Cr differ by
a factor of about 5 and cannot easily be mistaken for
each other.) For broad -crested weirs, C, varies between
2.63 and 3.33 ft°•s/sec (1.45 and L84 m0•s/s). (Use
3.33 ft0's/sec (1.84 m0 s/s) for initial estimates.) C. in-
creases as the upstream design head above the spillway
top, H, increases, and the larger values apply to the
higher heads.
Broad -crested weirs and spillways should be calibrated
to obtain greater accuracy in predicting flow rates.
Scour protection is usually needed at the toe of a spill-
way to protect the area exposed to a hydraulic jump.
This protection usually takes the form of an extended
horizontal or sloping apron. Other measures, however,
are needed if the tailwater exhibits large variations in
depth.
IS. PROPORTIONAL WEIRS
................................-...... ..................................
The proportional weir (Sutro weir) is used in water level
control because it demonstrates a linear relationship be-
tween Q and H. Figure 19.10 illustrates a proportional
weir whose sides are hyperbolic in shape.
Q=CdK(2) 2gH 19.81
K = 2x •y 19.62
Figure 19.10 Proportional Weir
19. FLOW MEASUREMENT
WITH PARSHALL FLUMES
The Parshall flume is widely used for measuring open
channel wastewater flows. It performs well when head
losses must be kept to a minimum and when there are
high amounts of suspended solids.
The Parshall flume is constructed with a converging up-
stream section, a throat, and a diverging downstream
section. The walls of the flume are vertical, but the
floor of the throat section drops. The length, width,
and height of the flume are essentially predefined by
the anticipated flow rate.9
"This chapter does not attempt to design the Parshall flume, only
to predict flow rates through its use
U B L I C A T I O N S INC.
STORAGE VOLUME CALCULATIONS
NOTE:
THE REQUIRED VOLUME FOR THE 100-YR. WSE WITH AN ADDED 10% FOR
SEDIMENTATION IS 29,511 CF. DEPTH = 2.26 FT
STORM
EVENT
ELEVATION
DEPTH
(FT)
VOLUME PROVIDED
(CF)
VOLUME REQUIRED
(CF)
304.37
0.00
0
305.00
0.63
1.813
2 YR
305.83
1.46
13,145
13,145
306.00
1.63
15,532
5 YR
306.05
1.68
16,594
16,594
10 YR
305.17
1.80
19,316
19,316
25 YR
306.31
1.94
22.423
22,423
50 YR
1 306,46 1
2.09
1 25,760 1
25,760
306.50
2.13
26,538
100 YR
306.51
2.14
26,829
26,829
307.00
2.63
37,887
307.50
3.13
49,596
NOTE,
1. THE WEIR COEFFICIENT, C=3.33, FOR BROAD
CRESTED WEIRS WAS TAKEN FROM CHAPTER 19,
SECTION 17, PG. 19-13 OF THE CIVIL ENGINEERING
REFERENCE MANUAL ELEVENTH EDITION, BY
MICHAEL R. LINDEBURG.
WEIR DISCHARGE CALCULATIONS
Q=CNL KhI's
L= 8.479' (8'-5 X"), C=3.33
INVERT= 304.37
FLOW RATES BASED
STORAGE DEPTHS BASED
ON STORAGE DEPTHS
DN ALLOWABLE DISCHARGE
STORM
ALLOWABLE
STAGE
WEIR
SOLVE
STAGE
EVENT
DISCHARGE
(FT)
DISCHARGE
FOR "h'
(FT)
(CFS)
(CFS)
(FT)
2-YR
50.61
305.83
49.81
1.48
305.85
5-YR
61.54
306.05
61.48
1.68
306.05
10-YR
69.08
306.17
6B.19
1.82
306.19
25-YR
78.89
306.31
76.29
1.98
306.35
50-YR
89.18
306.46
85.31
2.15
306.52
100-YR
93.11
88.39
89.48
2.22
306.59
I=XHIBIT G
DETENTION CALCULATIONS
100- YR STORM EVENT
PRE -DEVELOPED FLOW RATE 117.85 CFS
TO NORTH FROM WILLIAMSGATE
& BUENA ADA SUBDIVISION
PRE -DEVELOPED FLOW RATE 5.24 CFS
TO ROCK PRAIRIE R.O.W. FROM
BUENA 'ADA SUBDIVISION
POST -DEVELOPED FREE -FLOW 4.62 CFS
TO ROCK PRAIRIE R.O.W. FROM
BUENA ADA SUBDIVISION
POST -DEVELOPED FREE -FLOW 17.41 CFS
FROM WRLIAMSGATE SUBDIVISION
TO NORTH
POST -DEVELOPED FREE -FLOW 3.45 CFS
FROM BUENA ADA SUBDIVISION
TO NORTH
POST -DEVELOPED FREE -FLOW 3.88 CFS
FROM UP -STREAM OFF -SITE
FLOW
ALLOWABLE RELEASE RATE: 93.11 CFS
REQUIRED DETENTION VOLUME: 0.616 AC -FT
PROVIDED DETENTION VOLUME: 0.677 AC -FT
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE ,f 86942
DATE: 09/16/2010
m
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DRAWN: HEI
DATE: 11/16/09
HEI #: 09-119
@rr')i [99W a@°
@9IC33
F=XHIBI-F H
SwrtARY SfNEA YNIMXE
YHIIA4f SLWEN ONE
.OKN SMLP 4W.
S.. SEwEA ONE
hLEPNONE VNOLS1Y
IEIIDNCNE ONE
IEtEN51CN N
L.91E
t MRC
NARK FN
.R
MARK ONE
VKYL
ON, HNxWt
ME
1&
baENXGD OECf. ONE
PoMEN PSE
LICHT P.
. G HE
G
(A iFlltE COPPER)
CNAN LINK fGAL
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Ou D.L. VM4S)
( S
NOTES
I. BASS OF BEARINGS IS WE NORITIKST RIGHT OF WAY LINE
OF ROCK PRAIRIE ROAD ACCORDING TO THE PLAT OF
KILLIAMSCATE SUBDINSION, PHASE ONE RECORDED IN VOL. 7705
PG. 206 WTH A RECORD BEARING OF S 44'17'3VIV.
2. CURRENT TIlE APPEARS TO BE VESTED IN 10536E LLC 81
MRTUE OF DEED RECORDED IN VOL. 9498E PG. 232 OF THE
OFFICIAL RECORDS OF BRAZOS COUNTY. TEXAS.
3. THE SUBJECT TRACT DOES NOT UE M N114 THE 100 YEAR
FLOODPLAIN ACCORDING TO THE F.E.M.A FLOOD INSURANCE
RATE MAPS FOR BRAZOS COUNTY, TEXAS AND INCORPORATED
AREAS. COMMUNITY NO, 4800B3. PANEL NO. 0182C, MAP NO.
48041COI82C. EFFECDVE DATES: JULY 2. 1992.
4. 1/2- IBM RODS SET AT ALL CORNERS UNLESS OMERNISE
SPECIFIED.
CURVE TABLE
WPK lFN.. MNUS OgTA CNCRV MApWC
EI 5Z2W MW 65'5756' S 46'J2'WW' 54.19'
C2 1JOY 2&W 29'025 S 2S'S6'E9'W�1385'
G 2%5 INK05 724S9' N 4914'S5' INGA5'
5VR"EIEP. AVEUSI, 2010 � �/may �
RUNG
..Pp9toet6 �_
SY, RVNG NPLS 20J1
S.M. KUNG
.Q
2i� ffnnp��10
SUR
TOPOGRAPHIC
SURVEY PLAT
OF
10536E LLC
11.67 ACRE TRACT
CRAWFORD BURNETT SURVEY, A-7
COLLEGE STATION, BRAZOS COUNTY, TEXAS
SCALE: 1"=50' AUGUST, 2010
1m, mw,w...o. •n. 41. 4 e-....Nn11.0.011
Technical Design Summary Report
Buena Vida
Appendix II
I. Hydrologic and Hydraulic Computations
Detention area/volume capacity calculations
Modified Rational Method for Stormwater Detention Design
Buena Vista[Williamsgate- Detention Pond- Proposed
Brazos County, Texas
Purpose: Use the Modified Rational Method method to determine the volume of stormwater storage
needed to compensate for increased runoff due to development.
ssumptions: There are no upstream detention areas and the basin is less than 200 acres.
Method: Use the Rational Method to determine storm water runoff Q = K * C * I * A
Where: K = Antecedent Precipitation Coefficient C = Runoff Coefficient
I = Rainfall Intensity (in/hr) A = Drainage Area (acres)
Brazos County
Return
Period
i = b1(Ta+d)4e
b
d
e
2
65.00
8
0.806
5
76.00
8.5
0.785
10
80.00
8.5
0.763
25
89.00
8.5
0.754
50
98.00
8.5
0.745
100
96.00
8
0.730
I. Determine Site Parameters
Pre -development Conditions
Where: K =
1.00
A =
20.26
acres
C =
0.45
T� =
10.18
minutes
Post -development Conditions
Where: K =
1.00
T� =
10
minutes
Developed area C =
0.63
Developed area =
10.67
acres
Ex. Developed area C =
0.54
Ex. Developed area =
5.72
acres
Ex. Pass Through C =
0.45
Ex. Pass Through Flow =
2.50
acres
Composite C =
0.58
Total area =
18.89
acres
Free Flow area=
3.87
acres
II. Required Storage Calculations, Return Period = 2 years
Where: Qgrrrelease = 50.61 cis 1= 6.33 in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
in/hr)
(cfs)
(c
cfs
c
c
ac-ft
5
8.22
89.94
26,981
50.61
22,776
4,205
0.097
10
6.33
69.19
41,512
50.61
30,368
11,144
0.256
15
5.19
56.78
51,104
50.61
37,959
13,145
0.302
20
4.43
48.46
58,149
50.61
45,551
12,597
0,289
25
3.88
42.45
63,670
50.61
53,143
10,527
0.242
30
3.46
37.88
68,192
50.61
60,735
7,457
0.171
40
2.87
31.38
75,318
50.61
75,919
-601
-0.014
50
2.46
26.94
80,829
50.61
91,103
-10,274
-0.236
60
2.17
23.70
85,323
50.61
106,287
-20,963
-0.481
120
1.30
14.23
102,492
50.61
197,389
-94,898
-2.179
180
0.95
10.44
112,777
50.61
288,492
-175,715
-4.034
360
0.56
6.08
131,265
50.61
561,800
-430,536
-9.884
Capacity Required: 13,145 cubic feet 0.302 acre-feet
Required Storage Calculations, Return Period = 5 years
Where: 05wrelease as 61.54 cis with 1= 7.69 in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
in/hr)
(cfs)
(c
cfs
c
c
ac-ft
5
9.85
107.73
32,320
61.54
27,694
4,626
0.106
10
7.69
84.13
60,477
61.54
36,926
13,551
0.311
15
6.38
69.72
62,751
61.54
46,157
16,594
0.381
20
5.48
59.93
71,911
61.54
55,389
16,522
0.379
25
4.83
52.78
79,177
61.54
64,620
14,557
0.334
30
4.33
47.32
85,183
61.54
73,852
11,332
0.260
40
3.61
39.48
94,748
61.54
92,315
2,434
0.056
50
3.12
34.08
102,229
61.54
110,778
-8,549
-0.196
60
2.75
30.11
108,381
61,54
129,240
-20,859
-0.479
120
1.68
18.37
132,285
61.54
240,018
-107,733
-2.473
180
1.24
13.60
146,883
61.54
350,796
-203,912
-4.681
360 7T77T7-31
8.04
173,568
1 61.54
683,128
-509,561
1 -11.698
Capacity Required: 16,594 cubic feet 0.381 acre-feet
Required Storage Calculations, Return Period =10 years
Where: Q1e,.rrelease = 69.08 cis with 1= 8.63 in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
in/hr)
(cfs)
(c
cfs
c
c
ac-ft
5
10.98
120.09
36,026
69.08
31,085
4,942
0.113
10
8.63
94,43
56,656
69.08
41,446
15,210
0.349
15
7.19
78.67
70,805
69.08
51,808
18,997
0.436
20
6.21
67.90
81.485
69.08
62,169
19,316
0.443
25
5.49
60.03
90,038
69.08
72,531
17,507
0.462
30
4.94
53.98
97,165
69.08
82,892
14,273
0.328
40
4.14
45.26
108,626
69.08
103,615
5,011
0.115
50
3.59
39.23
117,686
69.08
124,339
-6,652
-0,153
60
3.18
34.78
125,203
69.08
145,062
-19,859
-0.456
120
1.97
21.52
154,947
69.08
269,400
-114,453
-2.627
180
1.47
16.07
173,502
69.08
393,739
-220,28
-5.056
360
0.88
9.63
208,069
69.08
766,755
558:6 6
-12.826
Capacity Required: 19,318 cubic feet 0.443 acre-feet
Required Storage Calculations, Return Period = 25 years
Where: 025vrrelease = 78.89 cis with 1= 9.86 in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
inlhr)
(cfb)
(c
cfs
c
c
ac-ft
5
12.51
136.76
41,029
78.89
35,502
5,527
0.127
10
9.86
107.84
64,707
78.89
47,336
17,371
0.399
15
8.23
90.04
81,040
78.89
59,170
21,871
0.502
20
7.12
77.86
93,427
78.89
71,004
22,423
0.515
25
6.30
68.92
103,384
78.89
82,838
20,546
0.472
30
5.67
62.06
111,707
78.89
94,671
17,035
0.391
40
4.77
52.14
125,143
78.89
118,339
6,804
0.156
50
4.14
45.27
135,810
78.89
142,007
-6,198
-0.142
60
3.68
40.19
144,689
78.89
165,675
-20,986
-0.482
120
2.29
25.01
180,079
78.89
307,682
-127,603
1 -2.929
180
1.71
18.74 1
202,341
78.89
449,690
-247,349
-5.678
360
1.03
11.30
244,121
78.89
875,711
1 -631,591
1 -14.499
Capacity Required: 22,423 cubic feet 0.515 acre-feet
Required Storage Calculations, Return Period = 50 years
Where: QWrrelease se 89.18 cfs with 1= 11.15 in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
in/hr)
(cfs)
(c
cfs
c
c
ac-ft
5
14.10
154.16
46,249
89.18
40,132
6,117
0.140
10
11.15
121.91
73,146
89.18
53,509
19,636
0.451
15
9.33
102.01
91,807
89.18
66,887
24,921
0.572
20
1 8.08
88.35
1 106,024
89.18
80,264
25,760
0.501
25
7.16
78.33
117,493
89,18
93,641
23,852
0.548
30
6.46
70.62
127,112
89.18
107,019
20,093
0.461
40
5.44
59.46
142,697
89.18
133,773
8,923
0.205
50
4.73
51.71
155,121
89.18
160,528
-5,407
-0.124
60
4.20
45.97
165,498
89.18
187,283
-21,784
-0.500
120
2.63
28.77
207,148
89.18
347,811
-140,663
-3.229
180
1.98
21.63
233,559
89.18
508,339
-274,780
-6.308
3601
1.20
13.12
283,490
89.18
989,923
-706,433
-16.217
Capacity Required: 25,780 cubic feet 0.591 acre-feet
Required Storage Calculations, Return Period =100 years
Where: Qraovrrelease = 93.11 cis with 1= 11.64in/hr
Duration
Rainfall
Intensity
Inflow
Rate
Inflow
Volume
Release
Rate
Outflow
Volume
Storage
Volume
Storage
Volume
min
in/hr)
(cfs)
(c
cfs(COc
ac-ft
5
14.76
161.42
48,425
93.11
41,902
6,523
0.150
10
11.64
127.28
76,371
93.11
55,869
20,502
0.471
15
9.73
106.43
95,787
93.11
69,836
25,951
0.596
20
8.43
92.19
1 110.632
93.11
83,80.",
26,829
0.616
25
7.48
81.77
122,660
93.11
97,770
24,889
0.571
30
6.75
73.77
132,787
93.11
111,738
21,050
0.483
40
5.69
62.20
149,290
93.11
139,672
9,618
0.221
50
4.95
54.18
162,534
93.11
167,606
-5,072
-0.116
60
4.41
48.24
173,659
93.11
195,541
-21,882
-0.502
120
2.78
30.40
218,874
93.11
363,147
-144,272
-3.312
180
2.10
22.96
247,979
93.11
530,753
-282,774
-6.492
360
1.29
14.06
303,746
93.11
1,033,572
729,826
-16.754
Capacity Required: 28,829 cubic feet 0.618 acre-feet
I. Pond Volume Calculations
Incremental
Total
Event
Elevation
Area
Volume
Volume
feet
(sq. ft.
cubic ft.)
(ac. ft.)
(ac. ft.
cubic ft.
304.37
0.0
0.000
0
305.00
5,755.0
1,812.8
0.042
0.042
1,813
305.83
13,145
306.00
21,683.0
13,719.0
0.315
0.357
15,532
5 yr
306.05
16,594
10 r
306.17
19,316
25 r
306.31
22,423
50 r
306.46
25,760
306.50
22,341.0
11,006.0
0.253
0,609
26,538
100 r
306.51
26,829
+10%
306.63
29,511
307.00
23,055.0
11,349.0
0.261
0.870
37,887
307.50
23,780.0
11,708.8
0.269
1.139
49,596
volume Kegwrea 25,829
Technical Design Summary Report
Bethel Evangelical Lutheran Church
Appendix III
Miscellaneous
Overall Site Layout — Buena Vida
Grading Plan - Buena Vida
Erosion Control Plan - Buena Vida
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/// ASPHALT
Qr TELEPHONE MANHOLE
N POWER POLE
LIGHT POLE
DQ WATER VALVE
OSSMH SANITARY SEWER MANHOLE
-(5 FIRE HYDRANT
0m WATER METER
PRELIMINARY PLANS
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE g 86942
DATE: 09/16/2010
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GRADING LEGEND
2R. F.
IRON ROD FOUND
IRON ROD SET
X•
CUT X IN CONCRETE
F.C.P.
FENCE CORNER POST
///
ASPHALT
OT
TELEPHONE MANHOLE
0
POWER POLE
LIGHT POLE
T
WATER VALVE
O55MH
SANITARY SEWER MANHOLE
FIRE HYDRANT
0w
WATER METER
T.C.
TOP OF CURB
G
GUTTER
T.P.
TOP OF PAVEMENT
F.F.
FINISHED FLOOR
NG
NATURAL GROUND
xx—
EXISTING CONTOURS
—xxx—
PROPOSED CONTOURS
NG=31/.33
NG=312.00 t
t
NG=310.95
-II Ll
NG=310.32
Q(100)=4.91 CFS
DEPTH=0.63'
S=2.0% '...
n=0.03
Q(CAP0 D=1.01)=18.93 CFS
SECTION A —A
NOT TO SCALE
!LOT LINE
I
NG=314.35
NG=315.00
II
_
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Q(1oo)=3.30 CFS
DEPTH=0.36'
NG=3
S=1.0%
n=0.03
Q(CAPO D=0.66)=17.67 CFS
SECTION B—B
NOT TO SCALE
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CONSTRIICIION ACTIWD
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EXISTING CONTOURS
—xxx—
PROPOSED CONTOURS
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THE CONTRACTOR SHALL CONTACT N
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MINIMUM OF 48 HOURS PRIOR TO THE
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I
I
21 LF
PRFLIMINARY PLAN
THIS DOCUMENT IS FOR INTERIM
REVIEW AND IS NOT INTENDED FOR
CONSTRUCTION, BIDDING OR PERMIT
PURPOSES.
STEVEN R. HOMEYER, PE # 86942
DATE: 09/16/2010
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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 6 — 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.
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 SUMMARY
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,
at 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 — Project Administration
Start (Page 2.1)
Engineering and Design Professionals Information
Engineering Firm Name and Address:
Jurisdiction
{ �Oyy�c'7 _ ErvC�riJt j2rrJ6� 1NC_
City: Bryan
{ O �k Z9({ SZ 7
� College Station
Le(_ot Sot trt_E I -N -% SDZ9
Date of Submittal:
9-"I - io
Lead Engineer's Name .a(td Contact Info.(phone -mail, fax):
5rt M1M Z.tTt7/'tltYolZ f fit
Other:
Z--`IO(o-99SS S� 2�@�t0A4 r- C!1 ;
r , ca�-�
Supporting Engineering / Consulting irm(s):
Other contacts:
NA
NA
Developer / Owner / Applicant Information
Developer / Applicant Name and Address:
Phone and e-mail:
1053(., r_t-C
cn9--7o3- 7ot4
3(.08 c. Z9V ST0�Tr S-. t-rE I tZ
8tZ`CAr0iX-7'78oZ
Property Owner(s) if not Developer / Applicant (& address):
Phone and e-mail:
S AvtA E
SA+ME
Project Identification
Development Name: V motp.
Is subject property a site project, a single-phase subdivision, or part of a multi -phase subdivision?
S I PAG 3, ANSE7 If multi -phase, subject property is phase NA of NA
Legal description of subject property (phase) or Project Area:
(see Section II, Paragraph B-3a)
'C(LAC.TS ISZ Arm I82,01
IGi2AW+:oZl�-
C="Y-S"GucI A-9STZAC_T -701
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.
NA
General Location of Project Area, or subj ct property (phase):
V-Dr-L t?eA(X%Z%G 'ZOAD f WF—Pe? LCC;P /A.)7QSEC_-00 J
In City Limits?
Extraterritorial Jurisdiction (acreage):
Bryan: — acres.
Bryan: NA College Station: N A
College Station: I I . (01 acres.
Acreage Outside ETJ: m Q
STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
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 o>rt�`21G ,WAS
a--
developments:
AC-V-S
�CMA
��
1(s�Fc� L-M
-
f� 4(o CR�Fea2D'QL.t;:rJGff cG
1 ta.�.1 T iZ rot l
T2 &Z.1 C¢AOPo2-a 8c tX., Eif Le'A&A
_ LA,JE
rtz Ivw\ CZA^)r-� a,,P.n)srT LE -A "•
Named Regulatory Watercourse(s) & Watershed(s):
Tributary Basin(s):
sez-: CRI 1✓L'
ZISS, CSZJE=-14'-
Plat Information For Project or Subject Property (or Phase)
Preliminary Plat File #.?1-10-OO5pOlO?
Final Plat File #: 10-OO600IDate: S6FT 10
Name:Bltb1^IA V fPA
Status and Vol/Pg:
If two plats, second name: File #:
Status: 11, IN Date:
Zoning Information For Project or Subject Property (or Phase)
Zoning Type: ( Existing or Proposed? E�<ISTI ^ECase Code:
Case Date Status:
Zoning Type: A Existing or Proposed? Case Code:
Case Date Status:
Stormwater Management Planning For Project or Subject Property (or Phase)
Planning Conference(s) & Date(s):
Participants:
NA
1qA
Preliminary Report Required? NO Submittal Date "' Review Date '"-"'
Review Comments Addressed? Yes _a.� No _ In Writing? Y6S When? 9 i-I0
Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation
explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any.
/ V 1\
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 _NoY
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
Brazos County
Needed?
Yes
—No
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
TxDOT Needed?
_
Yes No Y_
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
TAMUS Needed?
_
Yes _ No
Permits For Project or Subject 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
/Y
No � Yes.
US Environmental
Prot ect'on Agency
*'
_
No Yes
Texas Commission on
Environmental Quality
y'
No —)<— Yes _
Brazos River
Authority
n
�.
No_X_ 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 Proposed Work
Existing: Land proposed for development currently used, including extent of impervious cover?
\JACar-AT
Site
— Redevelopment of one platted lot, or two or more adjoining platted lots.
Development
Building on a single platted lot of undeveloped land.
Project
X�' 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):
Construction of streets and utilities to serve one or more platted lots.
Subdivision
Development
Construction of streets and utilities to serve one or more proposed lots on
Project
lands represented by pending plats.
Site proiects: building ute(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.
i00 17-1 COTS
Size of
Proposed
Z ( S3 L.:
Project
I p (Y D TZ!>t rJ ACC t A% r'" ` ' S
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 B1) or a tributary thereof?
Is any part of subject property in floodplain
No Yes Rate Map
area of a FEMA-regulated watercourse?
Encroachment(s)
into Floodplam
Encroachment purpose(s): _ Building site(s) Road crossing(s)
areas planned?
_ Utility crossing(s) Other (explain):
No
NN
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.
NR
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?
Reference the study (& date) here, and attach copy if not already in City files.
Vim''
WILL t A�SGA'T� S�T3'� I V t S tort Imo.(-hQSE I
SLAr`Ic Z% rZ005
Is the stormwater maripg9ment plan for the property in substantial conformance with the
earlier study? Yes K No If not, explain how it differs.
'T tS plan i.l 1 AICOOZ_PC (_A7E-S A^Jb C.O1Z.2E.CT5.
PAS TS bi= 1� PPEVtG-S. 'Pc-A.tQ "TZ> OJE'bt.4.Cc
TIC AIM O%-, r l I O�F STOQwu�a.'rETL 'et..a r.l OFF
Le'►'V 1 r�JG -r4G SrTe- 'POST De=1/cLOl�rvtE7�IT
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.
Do existing topographic features on subject property store or detain runoff? No Yes
Describe them (include approximate size, volume, outfall, model, etc).
EXIS"TI/-�!G-I>E"TL'�tn0V'A por"z. C-0�STTLA"s
t.CT ��"�
Pt>2 t c:IF lat LA-t Aw-%SGATE' S.3&BDt�l tS t Cl � �Q. s.� _
iQ TLoKIM/�.-rE \/OLtwvv%E I ZI Ooo C..F:
Any known drainage or flooding problems in areas near subject property? No Yes
Identify: CrT`-f S'1147'F— Ii41'NI4.�Vc
CAM-PLAI /fit 1 'S T:Te�
tP1TLCsPe2't`T Ot..D"e-9_S
Based on location of study property in a watershed, is Type 1 Detention (flood control) needed?
( e able 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 X Yes If yes,
describesplits below. In Part 4 describe design conet for handling this.
Watershed or Basin
Larger acreage
Lesser acreage
'BEE C 5F- L
/o, (,-7
(Ar,LiWAvv`t-v-&AS►,.(
k
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) 312 2) '— 3) — 4)
Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable
concentrated section(s), small creek (non -regulatory), regulatory Watercourse or tributary);
s"ISEEr- i'iLT�� c..nfDEVECot�c9
�Tz�52.-r`C
Flow determination: Outline hydrologic methods and assumptions:
l.,LSb'a Tt. 4M c,ra At— Vht�i'i foD ^tip �'-��-Ct�.t .v�.TQ �LDW S
C - O,�i s IN T�tiJSrf4r �tr� l �i70 �oZ E1gCkI
A.
D e storm runoff drain from public easements or ROW onto or across subject property?
No _ Yes If yes, describe facilities in easement or ROW:
Are changes in runoff characteristics subject to change in future? Expglain
AS 'T* OFFSi1E A x--a& DeUtELGP� TttE Avv&O",11-
CW- Ik" r 4 of F iZ C-E I uo-9 3` 'j}F tS rv� O.`'i 4-�LLACL& A'T-E
3ASb"t� o^( +f o� is GZA'�t'b..
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).
'%>Z% A,t r�S ! rv'i D Awl G�<XSTi OX.-UV-A%r+>A.C6G blo. Yh
p�G�SS — ,e i-VAiA 1 FAvvi i `i '�ta�[ nt bSi' S V I l i�
T?,o-pc—e71•`i' '-1 c"'2 —T, it Wit_Lt tAv-\Sc-oxe tom`- G
As "lOz t R l b rY I-ris Nit- r..t lG PAL. 'D ES l Gn!
A v>-1> "D -N7E 7> TAN(L44e.`( 3 1 Zootp ,
STORMWATER DESIGN GUIDELINES Page S 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
easements
If yes for what part of length? -^ % Created by? _ plat, or
exist for any
instrument. If instrument(s), describe their provisions.
clC��c,l/�1b
part of
pathway(s)?
wt�� t+MMSGATi= f�}i4SE ( ,
5 No
as
�vvC�\1! Ot- E`/'�SEEvv«tivT IS
A t`�''t lox t rr. aTEt_Y !c-7 5
Where runoff must cross lower properties, describe characteristics of abutting lower
property(ies). (Existing watercourses? Easement or Consent squired?)
EV&F rho ex ST S
Pathway
Areas
Loku- o�-^SGA-'E ���SE t �E1ltZl�t r✓wT
"FE'fZ -D-{£ mt.,ltctr�AL. DevELo?rh��i
GtZ a^? r S le S 1 GN PC-ANS.
Describe any built or improved drainage facilities existing near the property (culverts,
bridges, lined channels, buried conduit, swales, detention ponds, etc).
(,Jll..l.t p,�v.�SCoATE `�t;ipcSE l S�BD 1KISt o�� .
Nearby
Drainage
Facilities
Do any of these have hydrologic or hydraulic influence on proposed stormwater
design? _ No _X Yes if yes, explain:
liiE EX%STtary two^» L.)II.C_ BE IrJ
5 t%E T3> Y.t.6tAc-A'-M "T ibST—D�vCi.Ot�C�
r-Lc,_as -Tb l'Px-�EvEWPt� 1�-A►LS.
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 Design 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.
'r(i exk s-r, NG c*tP-s i-m :'L L- s, wtc-
r3c��L�
-TO C�ON"il �IAE _M St-6---ET FLO_J G'V_iiJ 4-�
5t�3SECT-PTLE>-AS7_-Ti, I r r- ?_L'" O:PF WILL V6
F t^(
I; trtO(5Lrc'1::- Tfl -mz "b7_A1 rJA-C-c SSCSTE� w/Tr
'Trio k's�r�fL LDc>T* TLtx.) Ae.+D LALTrmA'TELY MO--E"9
- r-�QH 1-)- OrJ-S 11* 2-Tar11-1OrJ
Discharge(s) To Lower Property(les) (Section II, Paragraph E1)
Does project include drainage features (existing or future) proposed to become public via
Yes
platting? _,Y_ No _ Yes Separate Instrument? _X_No
Per Guidelines reference above, how will
Establishing Easements (Scenario 1)
runoff be discharged to neighboringg -�
property(ies)? VIA Anl O.-r7c�tT
Pre -development Release Scenario 2
p ( )
S'l,Q.I.�C•'MIZc 04,4 EAS0+,er r%
Combination of the two Scenarios
Scenario 1: If easements are proposed, describe where needed, and provide status of actions
on each. (Attached Exhibit #..... )
NA
Scenario 2: Provide general description of how release(s) will be managed to pre-developrent
conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit #F,14OZ)
���T�'V'CIOVJ iS J>TL00%'Otrt�, "Tlr> '>Z.!EC^al-a'•-�iT'>`
+-L.O-.DS Ti t- v Pw�c-v'C �>--> 1Ttaa�.
-ia-Je t'Tz a�5�1 e tcxaS w l L 36 DtSC14A 1� �
l/JiO A,r4 extSi't ^:)c. ✓hAr4 ✓v1Alb 54 aA1-r✓ O/�:
—1-He A pbce.)T NSTIZZFAY--�
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.
?�4A
If Scenario 2, or Combination are to be LksqO, has proposed design been coordinated with
owner(s) of receiving property(ies)? No _ Yes Explain and provide
documentation. UTtL1��rJG �a� OUS'i1a6�fL.�.IrJ°.0
(EvlSE1_^ r✓w tw! l"jl'i 7i T2� - 1%�-171�t� + L�7..� �+Al S ,
STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.2)
Stormwater Management Concept (continued)
Within Prolect Area Of Multi -Phase Project
Identify gaining Basins or Watersheds and acres s�iiftiing
Will project result
FL_0, ) S A4E McNkc-*E � ID t'R� ^Dr�iCCp1�D
in shifting runoff
between Basins or
between
What design and mitigation is used to compensate for increased runoff
Watersheds?
from gaining basin or watershed?
X,No
Yes
How will runoff from Project
1. With facility(ies) involving other development projects.
Area be mitigated to pre-
2 Establishing features
development conditions?
to serve overall Project Area.
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 #�
NA
2. For Overall Prolect Area (type & location of facilities): (Attached Exhibit # E 14Ee
�c TZ1 `1 1 o.J -FA Ct L I T`r IS 'TLC
rnA�r.tr�c�. ��lELo�rc'i� t-ux��S
3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in
subsequent questions of this Part. NN
Are aquatic echosystems proposed? _ No Yes in which phase(s) or
project(s)?
nn
w
r
Are other Best Management Practices for reducing stormwater pollutants proposed?
Q.
No Yes Summarize type of BMP and extent of use:
—
a
c
N A
o0
Z
If design of any runoff -handling facilities deviate from provisions of B-CS Technical
Specifications, check type facility(jes) and explain in later questions.
) dill I
Detention elements Conduit elements Channel features
Swales _ Ditches Inlets _ Valley gutters _ Outfalis
Culvert features — Bridges Other
STORMWATER DESIGN GUIDELINES Page 11 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 4.3)
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).
NA
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):
NA
Within Or Serving Subject Property (Phase, or Site)
If property part of larger ProjectArea, is design in substantial conformance with earlier analysis
and report for larger area? X. 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?
v
Steepest side slopes:
Usual front slopes:
Usual back slopes:
N
w
Flow line slopes: least
Typical distance from travelway:
typical greatest
(Attached Exhibit # )
O
w
Are longitudinal culvert ends in compliance with B-CS Standard Specifications?
Yes No, then explain:
At lriteections or otherwise, do valley gutters cross arterial or collector streets?
,No
_ Yes If yes explain:
U
w(U
Ar v ley gutters proposed to cross any street away from an intersection?
Z
No _ Yes Explain: (number of locations?)
u,
c
m m
STORMWATER DESIGN GUIDELINES Page 12 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 4.4)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Gutter line slopes: Least 0 8' o Usual Z'fl Greatest
Are inlets recessed on arterial and collector streets? _ Yes No If "no",
identify where and why.
x 11\
Will inlets capture 10-year d si n stormflow to prevent flooding of intersections (arterial
with arterial or collector)? X, Yes _ No If no, explain where and why not.
v
Will inlet size and placement prevent excee ing allowable water spread for 10-year
design storm throughout site (or phase)? Yes No If no, explain.
rn
Sao curves: Are inlets placed at low points? Yes No Are inlets and
conduit sized to prevent 100-year stormflow from onding at greater than 24 inches?
u
Yes No Explain "no" answers.
N
iU
N
N
m
Will 100-yr stormflow be cont in d in combination of ROW and buried conduit on
whole length of all streets? Yes _ No If no, describe where and why.
D si gns 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.
Pipe runs between system
Typical I50 Longest
a)
access points (feet):
Are junction boxes used at each bend? Yes _ No If not, explain where
and why.
o
Z
a
Are downstream soffi s at or below upstream soffits?
Least amount that hydraulic
Yes No If not, explain where and why:
grade line is below gutter line
S'l� 2 F(o3 Lt vE ` M - CaV^T>- AN
(system -wide):
���6 Stet✓ CtE+°��Cc
O,2PS f
STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 — Drainane 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
(include design discharge velocity, and angle between converging flow lines).
U
1) Watercourse (or system), velocity, and angle?
o
`D=' raw n or J 1�orvy� S �3 FPS Pm�9 8 T PS
,
aa) E
2) Watercourse (or system), velocity, and angle?
c 0
0 0
NE
cc
3) Watercourse (or system), velocity, and angle?
v
o
v n
E
For each outfall above, what measures are taken to prevent erasion or scour of
in N
receiving and all facilities at juncture?
m
1) C�orVGZc'—TE A1�'fzt-� �� �LI.��Mc
m
m
m
a)
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):
C1.
N
1 l
� N
c }
Flow line slopes (minimum and maximum):
0
NA0
Z
Outfall characteristics for each (velocity, convergent angle, & end treatment).
v
¢`
Will 100-year design storm runoff be contained within easement(s) or platted drainage
ROW in all instances? _ Yes No If "no" explain:
1QA
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 Desian Parameters
Continued (Page 4.6)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Pha e, or Site) (continued)
Are roadside ditches used? No Yes If so, provide the following:
t
_
Is 25-year flow contained withi 6 inches of freeboard throughout ? No
_Yes _
Are top of banks separated from road shoulders 2 feet or more? Yes No
o
_ _
Are all ditch sections trapezoidal and at least 1.5 feet deep? _ Yes No
For any "no" answers provide location(s) and explain:
°
NA0
If conduit is beneath a swale, provide the following information (each instance).
Instance 1 Describe general location, approximate length:
N�
N
r
Is 100-year design flow contained in conduit/swale combination? No
—Yes
"no" explain:
UIf
z N
Space for 100-year storm flow? ROW _ Easement Width
c
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
Z
and maximum slopes:
slopes, design storm:
o
_
vi a
m
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
c �
m
t �
U
C
g
Access Describe how maintenance access is provided (to swale, into conduit):
o
0 Co
� w
= c
a)
Instance 2 Describe general location, approximate length:
�N
ntA
'o
Is 100-year design flow contained in conduit/swale combination? Yes No
° o
_ _
If "no" explain:
c
E a)
Space for 100-year storm flow? ROW Easement Width
_ _
a
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
and maximum slopes:
slopes, design storm:
U0.
N
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
c
v
3 �
N
QAccess
Describe how maintenance access is provided (to swale, into conduit):
STORMWATER DESIGN GUIDELINES Page 15 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 4.7)
Stormwater 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
w
a
Is 100-year design flow contained in swale? Yes No Is swale wholly
r
_ _
within drainage ROW? Yes No Explain "no" answers:
m
Access Describe how maintenance access is provide:
O
Z
c
0
a
Instance 2 Describe general location, approximate length, surfacing:
0
�(A
o E
3 m
Is 100-year design flow contained in swale? _ Yes _ No Is swale wholly
owithin
drainage ROW? Yes No Explain "no" answers:
y O
_
of
Access Describe how maintenance access is provided:
U
d
CL
a
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 flo be channelized (deepened,
widened, or straightened) or otherwise altered? No Yes If only slightly
shaped, see "Swales" in this Part. if creating side ban s, provide information below.
Will design replicate natural channel? Yes No If "no', for each instance
o a
describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year
o w
I
design flow, and amount of freeboard:
m
Instance 1:
c
E
E
o
Instance 2:
n
E o
_ Z
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)
Stormwater 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:
149
For each location, describe length and general type of proposed improvement
(including fioodplain changes):
NA
For each location, describe section shape & area, flow line slope (min. & max.),
surfaces, and 100-year design flow.
�A
v
c
1195
Watercourses (and tributaries): Aside fro (fringe changes, are Regulatory
u
Watercourses proposed to be altered? No Explain below.
_L(_ _Yes
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
c
c
vAll
Proposed Channel Work: For all proposed channel work, provide information
requested in next three boxes.
If design is to replicate natural channel, identify location and length here, and describe
design in Special Design section this Part of Report.
�of
I�l\
Will 100-year flow be contained with one foot of freeboard? Yes No If
_ _
not, identify location and explain:
NA
Are ROW / easements sized to contain channel and required maintenance space?
Yes _ No If not, identify location(s) and explain:
NA
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? I For each provide info. below.
For each dry -type facilitiy:
Facility 1
Facility 2
Acres served & design volume + 10%
23,5 Pt .
29,511CF
100-yr volume: free flow & plugged
74o1W9C-
97,957
Design discharge (10 yr & 25 yr)
(09.08(3:
_M.169CFs
Spillway crest at 100-yr WSE?
yes _ no
_ yes _ no
Berms 6 inches above plugged WSE?
I —yes no
yes _ no
Explain any "no" answers:
-1?}1S'mO='ECT LC%-1LiDES-rtW OdiST1^t6-LeT&wno.J
tVht iLWl6VNEn1'TS, wE AW 'PR,0P0S1N6 Tio 2a tSE -T3H
v
AJJV. -3 5 -my 0.55 FEET -M -PTt01 cb—= to INCtkes 0i- tQee
v3GAZ> Altatc 'RiE 100-4V_ wSE, wE Pita-J'vE f-012 0, l0 P6E'T
oi- *ZaG"9bAeX> A$atS -[Y�G Yt AGGtE:"� L- E EWD E m0X,0 c.Y 00cm
�Qr
For each facility what is 25-yr design Q, and design of outlet structure?
Facility 1:7$,$F`J C-F-S'1}{�Cr \ /* QtCT14Nfol�LA2 Wa1�
0
Z
Facility 2:
Do outlets and spillways discharge into a public facility in easement or ROW?
Facility 1: Z_ Yes —No Facility 2: —Yes — No
If "no" explain:
o
--
a
0
-
For each, what is velocity of 25-yr design discharge at outlet? & at s ilp Iwav?
°'
Facility 1: 41-1 PPS & 3,0;:?5 Facility 2: -- &
0
Are energy dissipation measures used? No x Yes Describe type and
LL
IocationSXFFLE 'B(+xrS t.JceE IAtSTALt.r"D LJCn-li1^(
c
°
Jlt ex%%-ri�J6 OL4TCLT AS'PAZV
c
0
For each, is spillway surface treatment other than concrete? Yes or no, and describe:
Facility 1: YcS
Facility 2:
For each, what measures are taken to prevent erosion or scour at receiving facility?
Facility 173APPLE 3t�c1_S Ac�►17 (2.cudC-7ZT AI�R-i=r`(
Facility 2: —
If berms are used give heights, slopes and surface treatments of sides,
Facility 1: 1 ' S FOOT f1E 1(-FkT w `_X_4 c4 : i GTZ'A`SS
St.-o�S
Facility 2: --^
STORMWATER DESIGN GUIDELINES Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
zcwtWWI
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; H0, 2 Fool O'F RZEE
��_
BOc,i✓D Aao,[E 'T3iz io0—`i�1�1Z—PI—I.�C�C�cD siD¢w1
� v
tVCr�l 1,
L
Facility 2:
c a
0
0
c u
m
oFor
additional facilities provide all same information on a separate sheet.
Are parking areas to be used for detention? X No Yes What is
maximum depth due to required design storm?
oa side Dttches: 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:
�A
N
m
C
oAre
public
culverts parallel to public roadway alignment? Yes No Explain:
o
aC1STt�IG Z4 AT 1ZOCt`, %V_iE Ecy20>
n I
Creeks at Private Drives: Do private driveways, drives, or streets cross drainage
m
ways at serve Above -Project areas or are in public easements/ ROW?
No Yes If "yes" provide information below.
�Z�
How many instances? Describe location and provide information below.
r
�
Location 1:
2
NA
2
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 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 4.11)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Named Re qlalpry Watercourses & Tributaries): Are culverts proposed on these
facilities? No _ Yes, then provide full report documenting assumptions,
No
criteria, anal sis, programs, and study findings that support proposed
design(s). Is report provided? _ Yes _ No If "no", explain:
Arterial or Malor Collector Streets: Will culverts serve these types of roadways?
NNo
Yes How many instances? For each identify the
a
_
location and provide the information below.
ra
Instance 1: —
y
Instance 2: —
c
o
Instance 3: �—
c
0
0 m
Yes or No for the 100-year design flow:
1
2
3
z
E
o
Headwater WSE 1 foot below lowest curb top?
_—
—
—
c
Spread of headwater within ROW or easement?
—
E
a N
rn
Is velocity limited per conditions (Table C-11)?
--�
--
N
Explain any "no" answer(s):
0
0
N U
3 0
v
o :(D
Minor Collector gr Local Streets: Will culverts serve these types of streets?
No Yes How many instances? �_ for each identify the
a
location and provide the information below:
n a)
a
Instance 1: G!c�EfZ �� t°eT (ZoC1G �iZ�� tLI �= t
NInstance
2: —
u o
6
Instance 3: —
For each instance enter value, or "yes" / "no" for:
1
2
3
U a3
d �
Design yr. headwater WSE 1 ft. below curb top?
100-yr. max. depth at street crown 2 feet or less?
E
Product of velocity (fps) & depth at crown (ft) = ?
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
ix
APPENDIX D - TECHNICAL DESIGN
Part 4 — Drainage Concept and Design Parameters
Continued (Page 4.12)
Stormwater 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? X Yes No if not,
identify location(s) and intersect angle(s), and justify the design(s):
Does drainage way ali nment change within or near limits of culvert and surfaced
approaches thereto? No _ Yes If "yes" identify location(s), describe
change(s), and justifica ion:
Are flumes or conduit to discharge into culvert barrel(s)? No _ Yes if yes,
identify location(s) and provide justification:
Are flumes or c nduit to discharge into or near surfaced approaches to culvert ends?
_ No Yes If "yes" identify location(s), describe outfall design treatment(s):
S�..tZFACE 'L`2A�a,�.C-,c Fcz��,.�.. Ifs✓�"'Fc'SZ moo?
f� -DIZ A1 ril I N Tb jZ p C IC_ i' pG-O TCJ E
TZoA,aS 104F 'D I-T-C.4
Is scour/erosion protection provided to ensure IpDo term stability of culvert structural
0
components, and surfacing at culvert ends? Yes _No If "no" Identify
locations and provide justification(s):
G' l 5( c;il,i N(. +4i5 � L-N&,u-s 'P>tzou%ZNc1�
C*J C"�C4{ C 4p Gut—Ve-- Z'f"
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?
Nl\
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?
NA Yes No
_ If not, explain in Special Design Section of this Part.
STORMWATER DESIGN GUIDELINES Page 21 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 4.13)
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)?
NA
What drainage way(s) is to be crossed?
rn
v
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
�
d
Plan (SW3P)
established for
��102 CO Sil4e 1 OF Gc7.vSTlZtw�Oa
project construction?
to GT V 1 T 1 ES
m
_ No _>c Yes
Special Designs — Non -Traditional Methods
Are any non-traditional methods (aquatic echosystems, wetland -type detention, natural stream
pli tion, BMPs for water quality, etc.) proposed for any aspect of subject property project?
7r
No _ Yes If "yes" list general type and location below.
T�
N 1—\
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 proviidde�d/?� _ Yes No If "no" explain:
/ `l /\
STORMWATER DESIGN GUIDELINES Page 22 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 4.14)
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 ) -OF—TeNT 10 N
exI%TrF6 CON_61-rm,JS Wli?}t.v
ISOMy"\ ja
Ali -M T}ts EXtSTtNG
N Ir A S-a.J Fbe 4 m 114 SL_OV E of
2)
3)
4)
5)
Have elements been coordinated with the Engineer or her/his designee? For each item
above provide "yes" or "no", action date, and staff name:
1) YES — ALAaL A-S-r I (� ?AI O —T054i NOZ-rD- l
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:
-*;PAC-MZ- = O,r-(5
�osED"C" FNC--rc)Z = OAo3
TS=?,GO1 =zS-c`iiT.
1�=1 I,IS i ,cl=�= II,(d-4
What is the size and location of largest Design Drainage Area to which the Rational Formula
has been applied? G"I acres Location (or identifier): f'AZT cow
W�t.l_t P�.w.SfrATE (
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? DO %
As to intensity -duration -frequency and rain depth criteria for deter ning 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
tGp
i p0
Open channels
Swale/buried conduit combination in lieu of channel
Swales
10
' 00
Roadside ditches and culverts serving them
I
_
Detention facilities: spillway crest and its outfall
I DO
i p0
Detention facilities: outlet and conveyance structure(s)
too
too
Detention facilities: volume when outlet plugged
Culverts serving private drives or streets
_—
Culverts serving public roadways
too
too
Bridges: provide in bridge report.
Hydraulics
What is the range of design flow velocities as outlined below?
Design flow velocities;
I Gutters
Conduit
Culverts
Swales
Channels
Highest (feet per second)+137Lowest
(feet persecond)
, o
Streets and Storm Drain Systems Provide the summary information outlined below:
Roughness coefficients used: For street gutters: 0,013
For conduit type(s) 1' -- Coefficients: 0, 01
STORMWATER DESIGN GUIDELINES Page 24 of 26 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 4.16)
Design Parameters (continued)
Hydraulics (continued)
Street and Storm Drain Systems (continued)
For the following, area,59umptions other than allowable per Guidelines9
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? XYes _ No
Explain any "no" answers:
Are hydraulic grade lines calculated nd shown for design storm? Yes No
For 100-year flow conditions? Yes _ No Explain any "no" answers:
What tailwater conditions were assumed at ouffall point(s) of the storm drain system? Identify
each location and explain:
S"ft s�w� L f N "P.' "t t 13�Sc� o�i tT I IE
s-caew� LI••�c ` g' Wse Or [>CT& 0"
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:
N IN
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?
NAI
Entrance, friction and exit losses:
KR
Bridges Provide all in bridge report N
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
C-XCEt_ STeetavv� S Ht" ET5
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:
'jam De-re7 noiq -Pb^Zi > AAr,,(D A�SSoC t�aTE�
S'[aew. D2At,.! �t IDS AS DES��n1ED l.Jtt_L
�'t,.rlC.'110..( I P( ►4CL�2'DPcNCC W t"n-E L l'"C"`�
S-c�,va�2�S
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 for the proposed drainage
improv me s have be n issued or fall under applicable general permits."
ATE ' fE
/ice ''S it
111
�•
Licensed Professional Engler * : �6`.-t`W'� •'• *
# : •. ,
..
8%c�l t2 STEVEN R. HOMEYER
State of Texas PENo. Z•••••.••••.••••••......;•••••i
86942 _ _!r _ \1a
STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009