HomeMy WebLinkAboutAppendix D - Technical Design StandardSECTION 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
1EVhE CoNSv~ `T G-'~ c
City: Bryan
-2 S3
✓College Station
C c~ - Y 7 -T e-A Z
Date of Submittal:
tZ1131~~
Lead Engineer's Name and Contact Info.(phone, e-mail, fax):
Other:
ors )S. - Me-r L/4 "r
Supporting Engineering / Consulting Firm(s):
Other contacts:
Developer / Owner / Applicant Information
Developer / Applicant Name and Address:
Phone and e-mail:
Property Owner(s) if not Developer / Applicant address):
Phone and e-mail:
Project Identification
Development Name: yS Pr,L_"-g 3`e-2
Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision?
`S1 If multi-phase, subject property is phase of
Legal description of subject property (phase) or Project Area:
(see Section 11, Paragraph B-3a)
v1iXZ~ D
kit`s I I_T9 ~ ek<_
~,aeA•l,~ s
L~'-L 3 ye- -2
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.
NV A
General Location of Project Area, or subject property (phase):
C~-~1 WINS( 01%-L (N>e.
In City Limits?
Extraterritorial Jurisdiction (acreage):
Bryan: acres.
Bryan: College Station:
College Station: 3.3 Z acres.
Acreage Outside ETJ:
STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 2 - Project Administration
Continued (page 2.2)
Project identification (continued)
Roadways abutting or within Project Area or
subject property:
nnr~~-t l~ (LL-
Abutting tracts, platted land, or built
developments:
Named Regulatory Watercourse(s) & Watershed(s):
~u~-t.~c C per tax
Tributary Basin(s):
Plat Information For Project or Subject Property (or Phase)
Preliminary Plat File
Name:
Final Plat File Date:
Status and VoVPg:
If two plats, second name: File
Status: Date:
Zoning Information For Project or Subject Property (or Phase)
Zoning Type: 2-1 Existing Proposed? Case Code:
Case Date Status:
Zoning Type: Existing or Proposed? Case Code:
Case Date Status:
Stormwater Management Planning For Project or Subject Property (or Phase)
Planning Conference(s) & Date(s):
Participants:
Preliminary Report Required? Submittal Date Review Date
Review Comments Addressed? Yes No In Writing? When?
Compliance With Preliminary Drainage Report Briefly describe (or attach documentation
explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any.
STORMWATER DESIGN GUIDELINES Page 4 of 26 APPENDIX. U: I tt;N. UtalUN aUMMPXR7
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.
C
rdi
ti
Dept.
Contact:
Date:
Subject:
oo
na
on
With Other
Departments of
Jurisdiction
City (Bryan or
Colle
e St
ti
g
a
on)
Coordination With
Summarize need(s) & actions taken (include contacts & dates):
Non jurisdiction
City Needed?
Yes No
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
Brazos County
Needed? /
Y
es No c/
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
TxDOT Needed?/
Yes No V
Coordination with
Summarize need(s) & actions taken (include contacts & dates):
TAMUS Needed?/
Yes No v
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
Approved
?
Status of Actions include dates)
( )
US Army Crops of
Engineers
No Yes _
US Environmental
Protection Agency
No Yes
Texas Commission on
Environmental Quality
No Yes
Brazos River
Authority
f
No
Yes
STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 - Property Characteristics
Start (Page 3.1)
Nature and Scope of Proposed Work
Existing: Land proposed for development currently used, including extent of impervious cover?
VA-C A-r L4 NP' -71\ r- Cc>Jr--
Redevelopment of one platted lot, or two or more adjoining platted lots.
Site
Development
Building on a single platted lot of undeveloped land.
Project
Building on two or more platted adjoining lots of undeveloped land.
(select all
applicable)
Building on a single lot, or adjoining lots, where proposed plat will not form
a new street (but may include ROW dedication to existing streets).
Other (explain):
Subdivision
Construction of streets and utilities to serve one or more platted lots.
Development
Construction of streets and utilities to serve one or more proposed lots on
Project
lands represented by pending plats.
Site proiects: building use(s), approximate floor space, impervious cover ratio.
Subdivisions: number of lots by general type of use, linear feet of streets and
Describe
Nature and
drainage easements or ROW.
Size of
d L a-i c->
Proposed
Project
Is any work planned on land that is not platted
If yes, explain:
or on land for which platting is not pending?
Y
IZ
es
No
FEMA Floodplains
Is any part of subject property abutting a Named Regulatory Watercourse
No i,~ Yes
(Section II, Paragraph 61) or a tributary thereof?
Is any part of subject property in floodplain
No Yes ✓ Rate Map (`12- C
area of a FEMA-regulated watercourse?
Encroachment(s)
into Fooodplain
Encroachment purpose(s): Building site(s) Road crossing(s)
areas planned?
Utility crossing(s) Other (explain):
No
Yes
If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA-
approved Flood Study to define allowable encroachments in proposed areas? Explain.
STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 - Property Characteristics
Continued (Page 3.2)
Hydrologic Attributes of Subject Property (or Phase)
Has an earlier hydrologic analysis been done for larger area including subject property?
Yes
Reference the study date) here, and attach copy if not already in City files.
Is the stormwater management plan for the property in substantial conformance with the
earlier study? Yes No If not, explain how it differs.
No
If subject property is not part of multi-phase project, describe stormwater management
plan for the property in Part 4.
If property is part of multi-phase project, provide overview of stormwater management plan
for Project Area here. In Part 4 describe how plan for subject property will comply
therewith.
Do existing topographic features on subject property store or detain runoff? No Yes
Describe them (include approximate size, volume, outfall, model, etc).
Any known drainage or flooding problems in areas near subject property? No Yes
Identify:
Based on location of study property in a watershed, is Type 1 Detention (flood control) needed?
(see Table B-1 in Appendix B)
~etention 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
~JlPr
Part 3 - Property Characteristics
T Continued (Page 3.3)
Hydrologic Attributes of Subject Property (or Phase) (continued)
Does subject property straddle a Watershed or Basin divide? No Yes If yes,
describesplits below. In Part 4 describe design concept for handling this.
Watershed or Basin
Larger acrea a
Lesser acreage
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) 2) 3) 4)
Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable
concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary);
Flow determination: Outline hydrologic methods and assumptions:
Does 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? Explain
Conveyance Pathways (Section II, Paragraph C2)
Must runoff from study property dr . 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).
STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TEUN. ULbIUN SUMMrini
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 3 - Property Characteristics
Continued (Page 3.4)
Hydrologic Attributes of Subject Property (or Phase) (continued)
Conveyance Pathways (continued)
Do drainage
If yes, for what part of length? % Created by? plat, or
easements
instrument. If instrument(s), describe their provisions.
exist for any
part of
pathway (s)?
✓No
Yes
Where runoff must cross lower properties, describe characteristics of abutting lower
property(ies). (Existing watercourses? Easement or Consent aquired?)
Pathway
u"
S,j N-r Ae c> ol-
Areas
-
~r
Describe any built or improved drainage facilities existing near the property (culverts,
bridges, lined channels, buried conduit, swales, detention ponds, etc).
Y`s face
Nearby
Drainage
Facilities
Do any of thes ave hydrologic or hydraulic influence on proposed stormwater
design? No Yes If yes, explain:
STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
T 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.
Discharge(s) To Lower Property(ies) (Section II, Paragraph E1)
Does project include drainage features (existing or future) proposed to become public via
platting? No _-;-"Yes Separate Instrument? No Yes
Per Guidelines reference above, how will
stablishing Easements (Scenario 1)
runoff discharged to neighboring
P e
Pre-development Release (Scenario 2)
property (ies)?
Combination of the two Scenarios
Scenario 1: If easements are proposed, describe where needed, and provide status of actions
on each. (Attached Exhibit
Scenario 2: Provide general description of how release(s) will be managed to pre-development
conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit
-7 w2t6b -rt-V~Oc'rv &AIA-te. (-Au =rt
12
"
1
I
I
Combination: If combination is proposed, explain how discharge will differ from pre-
development conditions at the property line for each area (or point) of release.
If Scenario 2, or Combination are to be used, has proposed design been coordinated with
owner(s) of receiving property(ies)? No Yes Explain and provide
documentation.
STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Desian Parameters, I
Continued (Page 4.2)
Stormwater Management Concept (continued)
Within Project Area Of Multi-Phase Project
Identify gaining Basins or Watersheds and acres shifting:
Will project result
in shifting runoff
between Basins or
between
What design and mitigation is used to compensate for increased runoff
Watersheds?
from gaining basin or watershed?
,/"--No
Yes
How will runoff from Project
1. With facility(ies) involving other development projects.
Area be mitigated to pre-
2 Establishing features to serve overall Project Area.
development conditions?
Select any or all of 1, 2,
3. On phase (or site) project basis within Project Area.
and/or 3, and explain below.
1. Shared facility (type & location of facility; design drainage area served; relationship to size of
Project Area): (Attached Exhibit
2. For Overall Project Area (type & location of facilities): (Attached Exhibit
G~ P-~ l ~►~cr- , P
3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in
subsequent questions of this Part.
Are aquatic echosystems proposed? No Yes In which phase(s) or
project(s)?
C'.
a
i
Are other Best Management Practices for reducing stormwater pollutants proposed?
a
No Yes Summarize type of BMP and extent of use:
U)
c
rn
U)
O O
Z
If design of any runoff-handling facilities deviate from provisions of B-CS Technical
I
Specifications, check type facility(ies) and explain in later questions.
m
Detention elements Conduit elements Channel features
Q
Swales Ditches Inlets Valley gutters Outfalls
Culvert features Bridges Other
1
~
11
6«
I~
I
I~I
III
II
IN
~
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.3)
Stormwater Management Concept (continued)
Within Proiect 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).
/_C>N( '2C P C1C.r.SSt~
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):
Within Or Serving Subject Property (Phase, or Site)
If property part of larger Project Area, is design in substantial conformance with earlier analysis
and report for larger area? Yes No, then summarize the difference(s):
Identify whether each of the types of drainage features listed below are included, extent of use,
and general characteristics.
Typical shape?
Surfaces?
r-
0
W N
Steepest side slopes:
Usual front slopes:
Usual back slopes:
N }
N
Flow line slopes: least
Typical distance from travelway:
o
typical greatest
(Attached Exhibit
~z
v
I
m
°
Are longitudinal culvert ends in compliance with B-CS Standard Specifications?
Q
Yes No, then explain:
At intersections or otherwise, do valley gutters cross arterial or collector streets?
D
No Yes If yes explain:
0_0
N
Are valley gutters proposed to cross any street away from an intersection?
(D 3 Z
C
No Yes Explain: (number of locations?)
STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.4)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Gutter line slopes: Least Usual Greatest
Are inlets recessed on arterial and collector streets? Yes No If "no",
identify where and why.
Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial
with arterial or collector)? Yes No If no, explain where and why not.
cl-
v
a~
Will inlet size and placement prevent exceeding allowable water spread for 10-year
design storm throughout site (or phase)? Yes No If no, explain.
rn
Sag curves: Are inlets placed at low points? Yes No Are inlets and
conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches?
L 0
Yes No Explain "no" answers.
A~
~3
m
a~
2'
Will 100-yr stormflow be contained in combination of ROW and buried conduit on
Q
whole length of all streets? Yes No If no, describe where and why.
Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications?
Yes No If not, describe difference(s) and attach justification.
Are any 12-inch laterals used? No Yes Identify length(s) and where
used.
r•
(D
Pipe runs between system
Typil Longest
~ }
access points (feet):
I
Are junction boxes used at each bend? Yes No If not, explain where
and why.
~ o
~Z
~ I
E
Are downstream soffits at or below upstream soffits?
Least amount that hydraulic
w
Yes No If not, explain where and why:
grade line is below gutter line
(system-wide):
STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.5)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Describe watercourse(s), or system(s) receiving system discharge(s) below
(include design discharge velocity, and angle between converging flow lines).
v
1) Watercourse (or system), velocity, and angle?
c
N
0
E
2) Watercourse (or system), velocity, and angle?
c
C
0
C
E
u~ E
3) Watercourse (or system), velocity, and angle?
U.
(n a
0
O
P
a Q
,
V
For each outfall above, what measures are taken to prevent erosion or scour of
receiving and all facilities at juncture?
y
a)
1)
m
f0
n
(D
2)
0
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):
C,
a~
O
V5 C
c
Flow line slopes (minimum and maximum):
m
I
0
a
o
Z
~ \
Outfall characteristics for each (velocity, convergent angle, & end treatment).
m
v I
a~
Q
Will 100-year design storm runoff be contained within easement(s) or platted drainage
ROW in all instances? Yes No If "no" explain:
STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.6)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Are roadside ditches used? No Yes If so, provide the following:
Is 25-year flow contained with 6 inches of freeboard throughout ? Yes No
w
Are top of banks separated from road shoulders 2 feet or more? Yes No
o
a~
Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No
For any "no" answers provide location(s) and explain:
M
0
o!
If conduit is beneath a swale, provide the following information (each instance).
Instance 1 Describe general location, approximate length:
0
Is 100-year design flow contained in conduit/swale combination? Yes No
If "no" explain:
I U
0 m
Space for 100-year storm flow? ROW Easement Width
c
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
m
and maximum slopes:
slopes, design storm:
c
0
N V
N V
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
C T
C
.c
U ~
C
CL o
Access Describe how maintenance access is provided (to swale, into conduit):
0 w
f6
o
E
a~ w
= c
.(D
Instance 2 Describe general location, approximate length:
a E
N M
U N
7
U) v
Is 100-year design flow contained in conduit/swale combination? Yes No
If "no" explain:
c a
E t
Space for 100-year storm flow? ROW Easement Width
U
Swale Surface type, minimum
Conduit Type and size, minimum and maximum
and maximum slopes:
slopes, design storm:
0 CL
L) W
Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type):
m
~ c
3 °
Access Describe how maintenance access is provided (to Swale, into conduit):
STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.7)
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
E X
0 W
t
Is 100-year design flow contained in swale? Yes No Is swale wholly
}
within drainage ROW? Yes No Explain "no" answers:
Access Describe how maintenance access is provide:
~ O
Z
a
C
0
Instance 2 Describe general location, approximate length, surfacing:
v
a~
w
~
c
o E
c m
.
3
Is 100-year design flow contained in swale? Yes No Is Swale wholly
within drainage ROW? Yes No Explain "no" answers:
o
N O
X
Access Describe how maintenance access is provided:
U_
.D
7
n
Instance 3.4. etc. If swales are used in more than two instances, attach sheet
providing all above information for each instance.
"New" channels: Will any area(s) of concentrated flow be channelized (deepened,
widened, or straightened) or otherwise altered? No Yes If only slightly
shaped, see "Swales" in this Part. If creating side banks, provide information below.
c
Will design replicate natural channel? Yes No If "no", for each instance
o n
describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year
o w
design flow, and amount of freeboard:
CL
w
Instance 1:
tu
E
I
aD
>
0
Instance 2:
O.
z
m I
=
Instance 3:
~a
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:
For each location, describe length and general type of proposed improvement
(including floodplain changes):
For each location, describe section shape & area, flow line slope (min. & max.),
surfaces, and 100-year design flow.
v
a~
c
t
Watercourses (and tributaries): Aside from fringe changes, are Regulatory
Watercourses proposed to be altered? No Yes Explain below.
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:
Q
E
76
C
c
U
All 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 of this Part of Report.
Will 100-year flow be contained with one foot of freeboard? Yes No If
not, identify location and explain:
Are ROW / easements sized to contain channel and required maintenance space?
Yes No If not, identify location(s) and explain:
STORMWATER DESIGN GUIDELINES Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainacie 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? For each provide info. below.
For each dry-type facilitiy:
Facility 1
Facility 2
Acres served & design volume + 10%
Cx~
o 0
100-yr volume: free flow & plugged
2jog?~-
3 o
Design discharge (10 yr & 25 yr)
0"76
0- 83
Spillway crest at 100-yr WSE?
y- yes no
yes no
Berms 6 inches above plugged WSE?
yes no
yes no
Explain any "no" answers:
Cn
a~
I
For each facility what is 25-yr design Q, and design of outlet structure?
Facility 1: K-- ~ e
0
z
Facility 2:
I
Do outlets and spi ays discharge into a public facility in easement or ROW?
Facility 1: Yes No Facility 2: Yes No
If "no" explain:
a~
0
CL
0
a
For each, what is velocity of 25-yr design discharge at outlet? & at s ila IAW
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co
Facility 1: V Z_ ~2S & Facility 2: &
Are energy dissipation measures used? No Describe type and
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location:
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v
a~
For each, is spillway surface treatment other than concrete? Yes or no, and describe:
Q
Facility 1:
Facility 2:
For each, what measures are taken to prevent erosion or scour at receiving facility?
Facility 1:
Facility 2:
If berms are used give heights, slopes and surface treatments of sides.
Facility 1:
Facility 2:
STORMWATER DESIGN GUIDELINES Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Desian 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":
N
Facility 1; ~r S
a~
M (D
LL
Facility 2:
o c
_
C U
o
For additional facilities provide all same information on a separate sheet.
Are parking areas to be used for detention? No Yes What is
maximum depth due to required design storm?
Roadside Ditches: Will culverts serve access driveways at roadside ditches?
,,-'No Yes If "yes", provide information in next two boxes.
Will 25-yr. flow pass without flowing over driveway in all cases? Yes No
Without causing flowing or standing water on public roadway? Yes No
Designs & materials comply with B-CS Technical Specifications? Yes No
Explain any "no" answers:
cl-
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c
o
Are culverts parallel to public roadway alignment? Yes No Explain:
2
U N
fd
n
Creeks at Private Drives: Do private driveways, drives, or streets cross drainage
ways that serve Aove-Project areas or are in public easements/ ROW?
o
Z
No 6,-' Yes If "yes" provide information below.
I
How many instances? Describe location and provide information below.
d)
Location 1:
U
m
Location 2:
Location 3:
For each location enter value for:
1
2
3
Design year passing without toping travelway?
/ o
Water depth on travelway at 25-year flow?
O
Water depth on travelway at 100-year flow?
O
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 Conceat and Design Parameters
Continued (Page 4.11)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Named Regulatory Watercourses M Tributaries): Are culverts proposed on these
facilities? No Yes, then provide full report documenting assumptions,
criteria, analysis, computer programs, and study findings that support proposed
design(s). Is report provided? Yes No If "no", explain:
Arterial or Maior Collector Streets: Will culverts serve these types of roadways?
y
No Yes How many instances? For each identify the
location and provide the information below.
u
Instance 1:
1 Q
U)
Instance 2:
I
C
Instance 3:
C
0
0 m
Yes or No for the 100-year design flow:
1
2
3
E
o
Headwater WSE 1 foot below lowest curb top?
c
Spread of headwater within ROW or easement?
N
Is velocity limited per conditions (Table C-11)?
N
Explain any "no" answer(s):
0 0
N U
a N
0-0
Minor Collector or Local Streets: Will culverts serve these types of streets?
0 W
No Yes How many instances? for each identify the
location and provide the information below:
T
Instance 1:
a
Instance 2:
m
(n o
Instance 3:
-tf
For each instance enter value, or "yes" / "no" for:
1
2
3
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) = ?
SO
Is velocity limited per conditions (Table C-11)?
Limit of down stream analysis (feet)?
Explain any "no" answers:
STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Desian 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? Yes No If not,
identify location(s) and intersect angle(s), and justify the design(s):
Does drainage way alignment change within or near limits of culvert and surfaced
approaches thereto? No Yes If "yes" identify location(s), describe
change(s), and justification.
Are flumes or conduit to discharge into culvert barrel(s)? No Yes If yes,
identify location(s) and provide justification:
Are flumes or conduit to discharge into or near surfaced approaches to culvert ends?
No Yes If "yes" identify location(s), describe outfall design treatment(s):
c
C
C
0
U
Vl
Is scour/erosion protection provided to ensure long term stability of culvert structural
~j
components, and surfacing at culvert ends? Yes No If "no" Identify
locations and provide justification(s):
Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or
drainage easements/ ROW? Yes No if not, why not?
Do appreciable hydraulic effects of any culvert extend downstream or upstream to
neighboring land(s) not encompassed in subject property? No Yes If
"yes" describe location(s) and mitigation measures:
Are all culvert designs and materials in compliance with B-CS Tech. Specifications?
Yes No If not, explain in Special Design Section of this Part.
STORMWATER DESIGN GUIDELINES Page 21 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 4.13)
Stormwater Management Concept (continued)
Within Or Serving Subject Property (Phase, or Site) (continued)
Is a bridge included in plans for subject property project? No Yes
If "yes" provide the following information.
Name(s) and functional classification of the roadway(s)?
What drainage way(s) is to be crossed?
a~
rn
-o
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:
Z
Pollution Prevention
Plan (SW3P)
a
established for
m
pco nstruction?
o Yes
Special Designs - Non-Tradit
ional Methods
Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream
replic 'on, BMPs for water quality, etc.) proposed for any aspect of subject property project?
No Yes If "yes" list general type and location below.
Provide full report about the proposed special design(s) including rationale for use and
expected benefits. Report must substantiate that stormwater management objectives will not
be compromised, and that maintenanc~t will not exceed those of traditional design
solution(s). Is report provided? Yes No If "no" explain:
STORMWATER DESIGN GUIDELINES
Effective February 2007
Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters, I
Continued (Page 4.14)
Stormwater Management Concept (continued)
Wi
thin Or Serving Subject Property (Phase, or Site) (continued)
Special Designs - Deviation From B-CS Technical Specifications
If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of
B-CS Technical Specifications, check type facility(ies) and explain by specific detail element.
Detention elements Drain system elements Channel features
Culvert features Swales Ditches Inlets Outfalls
Valley gutters Bridges (explain in bridge report)
In table below briefly identify specific element, justification for deviation(s).
Specific Detail Element
Justification for Deviation (attach additional sheets if needed)
1)
2)
3)
4)
5)
Have elements been coordinated with the City Engineer or her/his designee? For each item
above provide "yes" or "no", action date, and staff name:
1)
2)
3)
4)
5)
Design Parameters
Hydrology
Is a map(s) showing all Design Drainage Areas provided? Yes No
Briefly summarize the range of applications made of the Rational Formula:
What is the size and location of largest Design Drainage Area to which the Rational Formula
has been applied? B -4S acres Location (or identifier):
STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.15)
Design Parameters (continued)
Hydrology (continued)
In making determjpmtions for time of concentration, was segment analysis used?
No ✓Yes In approximately what percent of Design Drainage Areas? C o %
As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any
criteria other than those provided in these Guidelines used? No Yes If "yes"
identify type of data, source(s), and where applied:
For each of the stormwater management features listed below identify the storm return
frequencies (year) analyzed (or checked), and that used as the basis for design.
Feature
Analysis Year(s)
Design Year
Storm drain system for arterial and collector streets
Storm drain system for local streets
Open channels
Swale/buried conduit combination in lieu of channel
Swales
Roadside ditches and culverts serving them
Detention facilities: spillway crest and its outfall
o o
ZS
Detention facilities: outlet and conveyance structure(s)
a
Z ,s
Detention facilities: volume when outlet plugged
Culverts serving private drives or streets
-jam
Culverts serving public roadways
Bridges: provide in bridge report.
Hydraulics
What is the range of design flow ve
locities as outlined below?
Design flow velocities;
Gutters
Conduit
Culverts
Swales
Channels
Highest (feet per second)
Lowest (feet per second)
Streets and Storm Drain Systems Provide the summary information outlined below:
Roughness coefficients used: For street gutters:
For conduit type(s) Coefficients:
STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainage Concept and Design Parameters
Continued (Page 4.16)
Design Parameters (continued)
Hydraulics (continued)
Street and Storm Drain Systems (continued)
For the following, are assumptions other than allowable per Guidelines?
Inlet coefficients? No Yes Head and friction losses No Yes
Explain any "yes" answer:
In conduit is velocity generally increased in the downstream direction? Yes No
Are elevation drops provided at inlets, manholes, and junction boxes? Yes No
Explain any "no" answers:
Are hydraulic grade lines calculated and shown for design storm? Yes No
For 100-year flow conditions? Yes No Explain any "no" answers:
What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify
each location and explain:
Open Channels If a HEC analysis is utilized, does it follow Sec VI.F.5.a? Yes No
Outside of straight sections, is flow regime within limits of sub-critical flow? Yes No
If "no" list locations and explain:
Culverts If plan sheets do not provide the following for each culvert, describe it here.
For each design discharge, will operation be outlet (barrel) control or inlet control?
Entrance, friction and exit losses:
Bridges Provide all in bridge report
STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009
SECTION IX
APPENDIX D - TECHNICAL DESIGN SUMMARY
Part 4 - Drainaae 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
l f..f~S ~~D►2o
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:
Attestation
Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical
Design Summary Drainage Report b 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
Unwed Drainage Design Guidelines for the owners of the property. All licenses and permits
required by any and all state and federal regulatory agencis; posed drainage
improvements have been issued or fall under applicable godft
Ax ~(P~®oe®•••Ws
.~t:1i n •
Licensed Professional Engineer • • • • • e • • @ • • • • • • •
® RABON A. METCALF
State of Texas PE No. ' 8 •
STORMWATER DESIGN GUIDELINES Page 26 of 26 VAPPENDIX. b: TECH. DESIGN SUMMARY
Effective February 2007 As Revised February 2009