HomeMy WebLinkAboutFolder\~'~\op~* FOR OFFICE USE ONLY
P&Z CASE NO.: _ _....,,._-/-'----4-L:::....+
C rTI OF COLLEGE STATION
Planning & Devefopmenr Services
!/'e., \ DATE SUBMITIED:
t:rE---t>CAN All PEFCJITrON-'
MINIMUM SUBMITTAL REQUIREMENTS
_..J_ Site plan application completed in full.
_..J_ $200.00 Application Fee.
_..J_ $200.00 Development Permit Application Fee.
,-l l '. J:?, . 1 . VlV
N/A $600.00 Public Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public
waterline, sewerline, sidewalk, street or drainage facilities is involved.)
_..J_ Twelve (12) folded copies of site plan
_..J_ One (1) folded copy of the landscape plan.
NIA One (1) copy of building elevation for all buildings.
N/A A list of building materials for all facades and screening for non-residential buildings.
NIA Color samples for all non-residential buildings.
N/A Traffic Impact Analysis (if applicable for non-residential buildings).
_..J_ A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they
are not checked off.
N/A Parkland Dedication requirement approved by the Parks & Recreation Board, please provide proof of
approval (if applicable).
Date of Preapplication Conference: ___ J_a_n_ua___.ry~2_0_06 ________________ _
NAME OF PROJECT Crescent Pointe Common Area 'H' -Drainage Improvements
ADDRESS 1700' Southwest of the Copperfield Parkway/SH 30 Intersection, Adjacent to SH 30 R.O.W .
LEGAL DESCRIPTION Crescent Pointe Common Area 'H' -per Final Plat & Replat Phase 2
APPLICANT/PROJECT MANAGER'S INFORMATION (Primary Contact for the Project):
Name Crescent Pointe Holdings. Inc. -Emanuel Glockzin -President
Street Address 4500 Carter Creek Pkwy, Suite 101 City Bryan
State ..-.TX _______ Zip Code ~77~8~0~2 ____ _ E-Mail Address _____________ _
Phone Number (979) 846-8878 Fax Number (979) 846-0783
PROPERTY OWNER'S INFORMATION:
Name Same as Applicant
Street Address -------------------City __________ _
State ______ Zip Code ______ _
Phone Number
ARCHITECT OR ENGINEER'S INFORMATION:
Name Kling Engineering & Surveying
Street Address 4101 Texas Ave. Ste. A
State """'"'TX'-'-----Zip Code ~77~8~0=2~----
PhoneNumber~(9~7=9~)8~4~6~-6=2~1=2=--------
6/13/03
E-Mail Address--------------
Fax Number ______________ _
City Bryan
E-Mail Address jeremy@klingeng.com
Fax Number (979) 846-8252
l of6
DEVELOPMENT PERMIT
PERMIT NO. 07-29
CITY OF COLLEGE STATION
Planning & Devtlopment Snvius
FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA
RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE
SITE LEGAL DESCRIPTION:
Crescent Pointe -Phase 2
Common Area "H"
1.06 Acres
DATE OF ISSUE: July 12, 2007
OWNER:
Crescent Po inte Holdings, Inc.
4500 Carter Creek Pkwy, Suite 101
Bryan, Texas 77802
TYPE OF DEVELOPMENT:
SPECIAL CONDITIONS:
SITE ADDRESS:
1700' southwest of Copperfield Pkwy I SH 30
DRAINAGE BASIN:
Carter's Creek
VALID FOR 12 MONTHS
CONTRACTOR:
Full Development Permit
All construction must be in compliance with the approved construction plans
All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section
7.5.E., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance, prior to any operations of
this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and
required to remain is strictly prohibited. The disposal of any waste material such as , but not limited to, paint, oil , solvents,
asphalt, concrete, mortar, or other harmful liquids or materials within the drip line of any tree requ ired to remain is also
prohibited.
Full Development Permit
The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site
in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design
Criteria . If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite, it is the
contractors responsibility to implement measures that will meet City, State and Federal requirements. The Owner and/or
Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any
silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any
disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be
responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment
as well as erosion, siltation or sedimentation resulting from the permitted work.
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure
that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage
facilities.
I hereby grant this permit for development of an area outside the special flood hazard area. All development shall be in
accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit
application for the above named project and all of the codes and ordinances of the City of College Station that apply.
Date
06/oe./07
I I Owner/~Contractor Date
KLING ENGINEERING & SURVEYING
Consulting Engineers • Land Surveyors
4101 Texas Avenue, Suite A Post Office Box 4234
Bryan, Texas 77802 Bryan, Texas 77805
B.J. Kling, P.E., R.P.L.S.
S.M. Kling, R.P.L.S.
Date: June 27, 2007
To: City of College Station
Planning and Development
From: Jeremy Peters
Telephone 979/846-6212
Fax 979/846-8252
Re: Crescent Pointe Common Areas 'H'
Response to City Comments 1
Landscaping/Streetscaping
1. Revision -Landscape point requirement corrected
2. Revision -Note added
Miscellaneous
1. Clarification -Irrigation system is extension of Common Area 'G' & 'I'. Backflow
prevention device installed at Common Area 'G' & 'I'
2. Acknowledged -Backflow devices must be installed per City Ordinance
Engineering
1. Clarification -Your assumption is correct. DA-6A-POST is the runoff generated and DA-
6A-POST Outfall is the flow exiting the Pond
2. Clarification -The top of the berm is 278.50'. Therefore, the freeboard at the 100 yr. event
is 0.7'. The emergency spillway is set at 278 .00'. In order to analyze this as a component
of the outlet works, the storage volume must be above the spillway flow line.
3. Revision -Further explanation included about area calculations
4. Clarification -At the 100 yr. event, the total flow to Texas A&M is 13 cfs in Table 6. In
Table 7, the 100 yr., post developed flow is 13 cfs. The 18 cfs referred to is the pre
developed flow.
5. Revision -Typo corrected
6. Revision -Drainage Area Map revised
7. Revision -Drainage Area Map revised
8. Clarification -The additional area of the pre developed conditions is accounted for in
Common Area 'G' & 'I' and 'F'
9. Clarification -Refer to Comment #2
10. Revision -Plan revised to show rip-rap berm to return discharge to sheet flow conditions.
pg 1 of 2
Electrical
1. No electrical required for Detention Pond construction.
pg 2 of2
DRAINAGE REPORT
FOR
Common Area 'H', Block 2 of Crescent Pointe Phase Two &
a Portion of Proposed Lot 6, Block 2 of Crescent Pointe Phase Five
Richard Carter Survey, A-8
College Station, Brazos County, Texas
April 25, 2007
Revised: June 27, 2007
DEVELOPED BY:
Crescent Pointe Holdings, Inc.
Emanuel Glockzin, Jr., President
4500 Carter Creek Parkway, Suite 101
Bryan, Texas 77802
PREPARED BY:
Kling Engineering & Surveying
4101 S. Texas Avenue, Suite A
Bryan, TX 77802
(979) 846-6212
Drainage Report
for
Crescent Pointe -Drainage Report -Page 1
Common Area 'H', Block 2 of Crescent Pointe Phase Two
&
a Portion of Proposed Lot 6, Block 2 of Crescent Pointe Phase Five
Richard Carter Survey, A-8
College Station, Brazos County, Texas
April 25, 2007
Revised: June 27, 2007
GENERAL LOCATION & DESCRIPTION:
For purposes of this drainage design and report, the "Project Area" shall be defined as
follows:
• A Portion of Lot 6, Block 2 (2.88 acres) of Phase 5
• Common Area 'H' (1 .06 acres) of Phase 2
The Project Area is located adjacent to State Highway 30 (SH 30), approximately 1700'
southwest of the intersection of Copperfield Parkway and SH 30. The Project Area is bounded on
southwest by Texas A&M property, on the northwest by the Common Area 'F', on the northeast by
the perpendicular extension of the Lot SR lotline to the SH 30 R.O.W., and on the southeast by the
SH 30 R.O.W. (refer to Appendix 1: "Vicinity Map").
Pre-development or existing conditions of the Project Area consist of vacant land covered
with a short grass pasture areas . The average sub basin slope is 2.0% as measured along the Project
Area's hydraulic length. Based on the current USDA National Resources Conservation Service Soil
Survey for Brazos County, Texas, the native soils are in hydrologic soil group D (refer to Appendix 5
-"Hydrologic Calculations -Pre Development Conditions"). Currently, office and commercial
developments are planned for the Project Area.
PURPOSE:
The purpose of this report is to document the stormwater management for the full
development of the Project Area. Proposed development for the areas included in this drainage
report consist of office uses. Detention will be provided within a privately maintained, project
specific drainage facility. Future development must be hydraulically compatible with this design.
Future development within the Project Area will only need to document that developed conditions
runoff coefficients do not exceed those assumed in this report and demonstrate conveyance of site
stormwater runoff to the drainage facility.
Crescent Pointe -Drainage Report -Page 2
DRAINAGE BASIN:
The site is located in the Carters Creek drainage basin, which is the primary drainage system.
The Project Area is in the secondary system and drains overland to an unnamed tributary of Carters
Creek (see Appendix 2: "General Location Map"). No portion of the site is within the 100 year flood
hazard area according to the Flood Insurance Rate Map for Brazos County, Texas and Incorporated
Areas number 48041C0161 C, Effective date: July 2, 1992, (see Appendix 3: "Flood Insurance Rate
Map").
The major sub-basin for the Project Area is approximately 3.94 acres (refer to Appendix 4
"Drainage Area Maps). The location of runoff evaluation is the boundary line between the Crescent
Pointe and Texas A&M properties. The sub-basin area is generally divided as follows:
2.88 acres: A portion of Lot 6, Block 2
1.06 acres: Common Area 'H'
DRAINAGE DESIGN CRITERIA:
Due to the expected increase in stormwater runoff for post development conditions, a
drainage facility will be designed to attenuate the 2 year through 100 year storm events.
Stormwater from the entire Project Area is to be conveyed to the drainage facility via overland
flow and future private storm sewer systems (private storm sewer not designed with this report).
It is imperative that during individual site development, the site grading & drainage plans
accommodate conveyance of storm water runoff to the correct drainage facility. Runoff from Lot
6, Block 2 shall be directed to two different drainage facilities in compliance with this report and
the Drainage Report for Lots 1-4. Block 2 Crescent Pointe Phase One. Vol. 6880. Pg. 188 & An
Additional 10.87 Acres o(Block 2 of Crescent Pointe. This is a requirement for all site areas as
depicted on the post developed drainage area map (refer to Appendix 4).
The Uplands Method was used to calculate travel times along sub-basin hydraulic lengths
and time of concentration.
The Rational Method was used to calculate peak runoff rates for both pre and post
developed conditions. A triangular hydro graph approximation with the following parameters was
used to develop runoffhydrographs:
Time to Peak (Tp) =Time of Concentration (Tc)
Tp = 1/3 Hydrograph Base Time (Rising Limb ofHydrograph)
3Tp = Hydrograph Base Time
The drainage facility design proposes a single, privately maintained detention pond. A
level pool pond routing procedure was used for post development conditions.
Crescent Pointe -Drainage Report -Page 3
DRAINAGE FACILITIES DESIGN:
Pre Development Conditions:
Project Drainage Areas:
The project sub-basin is divided into two drainage areas. Drainage area "DA-6A-PRE" is
3.82 acres and drains to the location of evaluation along the boundary with the Texas A&M
property. Drainage Area "DA-6REL-PRE" is 1.35 acres and drains to the SH 30 R.O.W. The
areas were delineated based on City of College Station 2' topographic maps, as well as field
surveyed topographic information (see Appendix 4: "Drainage Area Maps"). The following table
summarizes pre developed drainage areas and associated land cover.
DRAINAGE TOTAL
AREA AREA
(acres) (acres)
DA-GA-PRE 3.82
DA-GREL-PRE 1.35
TOTAL ACRES: 5.17
Table 1
Hydrologic & Hydraulic Analysis:
Intensities for the various storm events were computed based on the Brazos County
Intensity Duration Frequency curves for the corresponding times of concentration. Peak flow
rates for each drainage area were calculated using the Rational Method (refer to Appendix 5
"Hydrologic Calculations -Pre Development Conditions" for computations).
The following table summarizes the peak runoff rates for the various storm events.
Q (cfs)
DRAINAGE Tc C-Value Area 2 yr 5 yr 10 yr 25 yr 50 yr 100 yr
AREA (min\ (ac)
DA-GA-PRE 10.82 0.42 3.82 9.79 11 .93 13.41 15.32 17.32 18.08
DA-GREL-PRE 10.00 0.42 1.35 3.58 4.36 4.89 5.59 6.32 6.59
Table 2
The above peak flow rates were used in the existing conditions hydrograph generation.
Post Development Conditions:
Project Drainage Areas:
Under post developed conditions, the project's detention pond will discharge onto Texas
A&M property. Additionally, a portion of the site will continue to drain to the SH 30 R.O.W., as
it does under existing conditions. After the detention pond is graded, runoff that originates on
the southwest side of the pond berm will drain directly to the boundary line without being
detained. Level pool routing was used to model this detention pond, and the undetained
hydrograph was added at the detention pond discharge hydrograph. The peak discharge rates at
the property line will be limited to pre development discharge rates.
The project area should be directed to the detention pond, either sheet flow or storm
sewer. Due to the lack of final site plans for the Project Area, the assumption that maximum
Crescent Pointe -Drainage Report -Page 4
impervious lot coverage could not exceed 80% was made. The remaining 20% of the lot area is
assumed to be landscaped or grassed.
The following table summarizes post developed drainage areas, associated land cover and
the respective Rational runoff coefficient "C".
DRAINAGE TOTAL
AREA AREA POND D AREA
(acres) (C=0.77) (C=0.90) AREAS (acres)
C=0.42
DA-6A-POST 2.24 0.74 2.98
DA-68-POST 0.32 0.32
TOTAL ACRES: 2.88 0.74 0.32 3.94
Table 3
It should be noted that drainage areas DA-6B-POST and DA-6REL-POST do not flow
into the detention facility. DA-6REL-POST corresponds to the area released to the SH 30
R.O.W. under existing conditions, and DA-6B-POST is the runoff from the area on the
southwest side (downstream side) of the detention pond berm. Under post developed conditions,
the drainage areas are less than the pre developed drainage areas because portions of the pre
developed drainage areas are accounted for in adjacent detention facilities. This is shown in the
Drainage Report For Lots 1-4, Block 2 Crescent Pointe Phase One, Vo l. 6880, Pg. 188 & An
Additional 10.87 Acres of Block 2 a/Crescent Pointe and Drainage Report For Lot 3R, Block 2
Crescent Pointe Phase Two & An Additional 14.9 Acres of Block 2 of Crescent Pointe.
Proposed Drainage Improvements:
Project Area drainage improvements will consist of a single, privately maintained
detention pond. The existing site drains via overland flow, therefore the pond will be constructed
by creating a berm to detain the runoff.
Hydrologic & Hydraulic Analysis:
The fo llowing table summarizes the peak runoff rates for the various storm events.
Q (cfs)
DRAINAGE Tc I C-Value I Area 2 yr I 5 yr 10 yr I 25 yr I 50 yr 100 yr
AREA (min) (ac)
DA-6A-POST 10.00 0.80 2.98 15.10 18.36 20.61 23.54 26.61 27.78
DA-68-POST 10.00 0.42 0.32 0.86 1.05 1.18 1.34 1.52 1.59
DA-6REL-POST 10.00 0.77 0.64 3.12 3.80 4.26 4.87 5.50 5.75
*reported values vary slightly from calculated values due to differences in the runoff hydrograph and
routing procedure calculation time steps Table 4
Crescent Pointe -Drainage Report -Page 5
Detention Facilities Design:
The inflow hydrograph was routed through the detention pond using a level pool routing.
The runoffhydrograph from DA-6B-POST was added at the project outfall. DA6-POND is the
detention pond contained in Common Area 'H'. The pond outfall was modeled as a free outfall.
A rating table of Water Surface Elevation vs. Flow Rate is located in Appendix 6, "Detention
Routing Calculations -Post Development Conditions". Graphs of these rating tables for the
detention pond outlets are located on the attached CD for reference.
The following information documents design parameters used in the model.
Detention Pond Characteristics:
DA6-POND
Elev Area Volume Volume
Sum
(ft) (sq.ft) (ac-ft) (ac-ft)
276.30 0 0.000 0.000
277 10843 0.058 0.058
278 16628 0.313 0.371
278.50 17908 0.198 0.569
Table 5
The limits of DA6-POND are calculated to elevation 278 .50.
Outlet Works:
The DA6-POND outlet consist of2-18" RCP and a 100' long, 6' wide broad crested earthen weir.
Both RCP's are set at the same upstream and downstream flowline elevations. Additionally, a 9"
tall rock berm will return the discharge to sheet flow. The following is a summary of the outlet
structure.
DA6-POND:
Sizeffype: 2-1 8" RCP
Manning's n: 0.013
Upstream FL: 276.30
Downstream FL: 276.15
Horiz. Length: 26.0'
Slope: 0.60
Overflow Spillway:
Rock Berm:
Horiz. Length: 100'
@ elev. 278.00
Horiz. Length: 320 LF
@ elev. 276.75
Crescent Pointe -Drainage Report -Page 6
The following schematic diagram depicts the calculation sequence for the post developed
conditions hydrologic and routing model.
-----Network Dlo.gro."' -----
DA-6-PST-100
JIM ....
lllTFM.L
Figure 1
The following table summarizes results of post development storm water routing. Refer to
Appendix 6 "Detention Routing Calculations -Post Development Conditions" for computation
summary and the attached CD for graphical representation ofhydrographs and pond water surface
elevations.
PEAK DISCHARGE RATE STORM EVENT
(CFS)
2YR 5YR 10 YR 25YR 50YR 100 YR
DA-6A-POST 15 18 21 24 27 28
DA6-POND Inflow 15 18 20 23 26 27
DA-6A-POST Outfall / WSEL 7/277.4 81 277.5 9 / 277.6 10 /277.7 11 / 277.8 12 / 277.8
DA-6A-POST Discharge Velocity 4.36 4.57 4.70 4.85 4.98 5.02
DA-68-POST 1 1 1 1 2 2
Boundary Line Flow II 7 8 9 11 12 13
*reported values vary slightly from calculated values due to differences in the runoff hydro graph and routing
procedure calculation time steps
*"Boundary Line Flow" is the resultant hydrograph from DA-6A-POST and DA-6B-POST hydrograph addition
Table 6
Crescent Pointe -Drainage Report -Page 7
The overflow weir for the detention pond is not used for any storm event. Additionally, at
the 100 year event, freeboard of 0.7' is maintained for DA6-POND. Peak discharge rates at the
boundary line between Crescent Pointe and Texas A&M property are less than existing
conditions. Energy dissipaters are provided at the downstream end of the pond outlet works to
further limit the effects of outlet velocities.
The following table compares pre and post development peak discharge rates from the Project
Area at the boundary of Crescent Pointe and Texas A&M property.
PEAK DISCHARGE RATE (CFS) STORM EVENT
TO TEXAS A&M PROPERTY
2YR SYR 10 YR 25YR SOYR 100 YR
Pre Developed 10 12 13 15 17 18
Post Developed 7 8 9 11 12 13
% Attenuation II 143 150 144 136 142 138
Table 7
Additionally, the following table compares the pre and post development peak discharge rates that
are released from the Project Area, drainage areas DA-6REL-PRE and DA-6REL-POST, to SH 30
R.O.W.
PEAK DISCHARGE RATE (CFS) STORM EVENT
TO SH 30 R.O.W.
2YR SYR 10 YR 25YR SOYR 100 YR
Pre Developed 4 4 5 6 6 7
Post Developed 3 4 4 5 6 6
Table 8
Crescent Pointe -Drainage Report -Page 8
CONCLUSIONS:
The detention facility design complies with the City of College Station requirements. The
detention pond attenuates excess runoff through the 100 year storm event. No adverse impacts to
upstream or downstream lands or structures are expected.
"I hereby certify that this report for the drainage & detention design of: Common Area
'H', Block 2 of Crescent Pointe Phase Two & a Portion of Proposed Lot 6, Block 2 of
Crescent Pointe Phase Five was prepared under my supervision in accordance with the
provisions of the City of College Station Drainage Policy and Design Standards for the
owners thereof."
Al d A. Paine, P .E.
Licensed Professional Engineer
State of Texas No. 97221
APPENDICES
1) Vicinity Map
2) General Location Map
3) Flood Insurance Rate Map
4) Drainage Area Maps
5) Hydrologic Calculations -Pre & Post Development Conditions
6) Detention Routing Calculations -Post Development Conditions
APPENDIX 1
Vicinity Map
1
PROJECT
AREA
3.94 AC.
FM 60
VJCJNJTY MAP
APPENDIX 2
General Location Map
APPENDIX 3
Flood Insurance Rate Map
APPENDIX 4
Drainage Area Maps
APPENDIX 5
Combined Hydrologic Calculations
Pre Development Conditions
&
Post Development Conditions
INTENSITY CALCULATIONS
BRAZOS COUNTY
CONSTANTS FOR IDF CURVES
FREQ e b d
2 0.806 65 8.0
5 0.785 76 8.5
10 0.763 80 8.5
25 0.754 89 8.5
50 0.745 98 8.5
100 0.730 96 8.0
INTENSITY=b/(Tc+d)Ae
FREQ
Tc (min) 2 5 10 25 50 100
PRE
DA-GA 10.82 6.10 7.43 8.35 9.54 10.79 11 .26
DA-GREL 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64
POST
DA-GA 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64
DA-GB 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64
DA-GREL 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64
RUN-OFF COEFFICIENT CC-VALUE) CALCULATIONS
C-VALUES
PRE
DA-GA
DA-GREL
TOTAL:
POST
DA-GA
DA-G8
DA-GREL
TOTAL:
GRASS/WOODED 0.42 CHANNEL 0.90
IMP ERV 0.90 DEV 0.77
AREA in Acres
GRASS/WOODED IMP ERV CHANNEL TOTAL
3.8216 0.0000 0.0000 3.822
1.3490 0.0000 0.0000 1.349
5.1706 0.0000 0.0000 5.1706
DEV IMPERV UN DEV POND
2.2396 0.0000 0.0000 0.7363
0.0000 0.0000 0.3245 0.0000
0.6413 0.0000 0.0000 0.0000
2.8809 0 0.3245 0.7363
UN DEV
POND
TOTAL
2.9759
0.3245
0.6413
3.9417
PEAK FLOW CALCULATIONS
TC C-VALUE AREA Q2 Q5
PRE (minutes) (ac) (cfs) (cfs)
DA-GA 10.82 0.42 3.8216 9.79 11.93
DA-GREL 10.00 0.42 1.3490 3.58 4.36 .
POST
DA-GA 10.00 0.80 2.9759 15.10 18.36
DA-G8 10.00 0.42 0.3245 0.86 1.05
DA-GREL 10.00 0.77 0.6413 3.12 3.80
where: Q = C-Value *Area * I
I -is found in "Intensity Calculations" and corresponds to the
appropriate Tc and frequency.
0.42
0.9
Q10
(cfs)
13.41
4.89
20.61
1.18
4.26
C-AVE
0.42
0.42
0.80
0.42
0.77
Q25
(cfs)
15.32
5.59
23.54
1.34
4.87
Q50 Q100
(cfs) (cfs)
17.32 18.08
6.32 6.59
26.61 27.78
1.52 1.59
5.50 5.75
USDA Natural Resoarces
Conservatloa Senke
HYDROLOGIC GROUP RATING FOR BRAZOS COUNTY, TEXAS
••c;::~•-••Meters
0 15 30 60
Web Soil Survey 1.1
National Cooperative Soil Survey
•--==-•-=· ::J1•••-==::::;::::::::::J111!1t ••-Feet 0 50 100 200 300 400
3/5/2007
Page I of3.
USQA N•tural ResourctS
:iiiim Comen'atioD Senice
HYDROLOGIC GROUP RATING FOR BRAZOS COUNTY, TEXAS
MAP LEGEND
Hydrologic Group
{Dominant Conc:Ution, &It;}
A
c:::J AID -B c:J BID
c=i c
-CID
D
C=:J Not rated or not available
Soil Map Units
o Cities
c:::J DetailE!Q Counties c:::J Detailed States
-Interstate Highways
--Roads
-+---+ Rails
Water
--Hydrography
Oceans
MAP INFORMATION
Source of Map: Natural Resources Conservation Service
Web Soil Sµrvey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: UTM Zone 14
Soil Survey· Area: Brazos County, Texas
Spatial Version of Data: 1
Soil Map Compilation Scale: 1 :20000
The orthophoto or other base map on which the soil lines were compiled and
digitized probably diffe.rs from the background imagery displayed on these maps.
As a result, some minor shiftin of ma uni,t boundaries ma be evident.
Wep Soil Survey 1.1
National Cooperative Soil Survey
3/5/2007
Page 2 of3
Hydrologic Group Rating
Tables -Hydrologic Group
Summary by Map Unit -Brazos County, Texas
Soil Survey Area Map Unit Name Rating Total Acres in Percent of AOI
Map Unit AOI
Symbol
RbA Rader-Tabor complex, D 5.3 100.0
1 to 3 percent slopes
Description - Hydrologic Group
Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the
rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from
long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (ND, BID, and CID). The
groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well
drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep,
moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have
a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes
the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of
clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or
near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water
transmission.
If a soil is assigned to a dual hydro logic group (ND, BID, or CID), the first letter is for drained areas and the second is for
undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.
Parameter Summary -Hydrologic Group
Aggregation Method: Dominant Condition
Component Percent Cutoff:
Tie-break Rule: Lower
US!l<\ Natural Resovces
Comervati1111 Service
Web Soil Survey l.l
National Cooperative Soil Survey
3/5/2007
Page3 of3
APPENDIX 6
Detention Routing Calculations
Post Development Conditions
yyyJob File :yH :\ENGINE-l\CRESCE-1\DRAINAGE \PPK-TMP\DA6 .ppk
Rain Dir : .\util\
CRESCENT POINTE
DETENTION AREA 6
RICHARD CARTER, A-8
JOB TITLE
COLLEGE STATION, BRAZOS COUNTY, TEXAS
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yyyPond Pack Ver: 8 -01-98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02-21-2007
y
yyyTable of Contentsy i
Table of Contents
******************** NETWORK SUMMARIES *********************
DA-6-PST-25 ..... 25 YR
Executive Summary (Nodes) 1.01
************************ TIME VS .VOL ***********************
DA6 -POND OUT 25 YR
Time vs . Volume ................... . 2 .01
******************** OUTLET STRUCTURES *********************
DA6 -0UTLET ...... Outletyinput Data .... .
Composite Rating Curve
3 .01
3 .04
*********************** POND ROUTING ***********************
DA6-POND OUT 25 YR
Pond Routing Summary ..... 4 .01
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02-21-2007
y
yyyType .... Executive Summary (Nodes)
yyyNarne .... DA-6-PST-25
yyyFile .... H:\ENGINE-l \CRESCE-l \DRAINAGE\PPK-TMP\DA6 .ppk
yyyStorrn ... 25 YR yTag : 25 YR
NETWORK SUMMARY --NODES
yPage 1 .01
Event : 25 YR
(Trun .= HYG Truncation : Blank=None; L=Left ; R=Rt ; LR=Left & Rt)
HYG Vol Qpeak
Node ID Type ac-ft Trun . hrs
------------------------------------
DA-6-PST-25 HYG .486 R .1665
DA-6B -PST-25 HYG .028 .1665
DA6-POND IN POND .486 .1776
DA6-POND OUT POND .486 .3552
Outfall OUTFALL JCT . 513 .3330
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
Qpeak
cfs
--------
23 .51
1. 34
22.77
10 .08
10 .69
Max WSEL
ft
277 .68
yyyPond Pack Ver : 8-01-98 (61) yyyCornpute Time : 14 :47 :31 yyyDate : 02-21-2007
y
yyyType .... Time vs . Volume
yyyName .... DA6 -POND OUT yTag : 25 YR
yyyFile .... H:\ENGIN E-l\CRESCE-l \DRAINAGE\PPK-TMP\DA6 .ppk
yyyStorm ... 25 YR yTag: 25 YR
TIME vs . VOLUME (ac-ft)
yPage 2 .01
Event : 25 YR
Time Output Time incr ement = .0222 hrs
hr s I Time on left represents time for fir st value i n each row .
---------!--------------------------------------------------------------.oooo I
.1110 I
.2220 I
.3330 I
.4 44 0 I
.5550
.6660
.7770
.8880
.9990
1 . 1100
1 .2210
1 .3320
1 .44 30
1.5540
1 .6650
1 .7760
1 .8870
1 .9980
2 .1090
.000
.050
.195
.255
.236
.172
.117
. 072
.043
. 027
.010
.001
.000
.000
.000
.000
.000
.000
.000
.000
.000
. 077
.214
.257
.225
.160
.106
.065
.039
.025
.007
.001
.000
.000
.000
.000
.000
.000
.000
.003
.111
.230
.256
.212
.149
.097
.058
.035
.023
.005
.001
.000
.000
.000
.000
.000
.000
.000
yyyS/N : HOMOL013280 9 Kling Engi neeri ng & Sur veyi ng
.022
.146
.242
.252
.198
.140
.088
.052
.032
.022
.003
.000
.000
.000
.000
.000
.000
.000
.000
.033
.172
.250
.245
.184
.128
.079
.047
.030
.015
.002
.000
.000
.000
.000
.000
.000
.000
.000
yyyPond Pack Ver: 8 -0 1 -98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02 -2 1-2007
y
yyyType .... Outletyinput Data
YYYName .... DA6 -0UTLET
YYYFile .... H:\ENGINE-l\CRESCE-l \DRAINAGE\PPK-TMP\DA6 .ppk
REQUESTED POND WS ELEVATIONS :
Min . Elev .=
Increment =
Max. Elev .=
276 .30 ft
.50 ft
278 .50 ft
**********************************************
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (Upstream to DnStream)
<---Reverse Flow Only (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure
Culvert-Circular
We i r -Rectangular
TWYSETUP ,yDS Channel
No .
--->
--->
Outfall
TW
TW
El , ft
276 .300
278 .100
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yPage 3.01
E2 , ft
278 .500
278 .500
YYYPond Pack Ver : 8-01-98 (61) yyycompute Time: 14 :47 :31 yyyDate : 02 -21-2007
y
yyyType .... Outletyinput Data yPage 3 .02
yyyName .... DA6 -0UTLET
yyyFile .... H:\ENGINE-l\CRESCE-l\DRAINAGE\PPK-TMP\DA6 .ppk
OUTLET STRUCTURE INPUT DATA
Structure ID
Structure Type Culvert-Circular
Use
Use
No . Barrels
Barrel Diameter
Upstream Invert
Dnstream Invert
Horiz . Length
Barrel Length
Barrel Slope
OUTLET CONTROL DATA ...
Mannings n
Ke
Kb
Kr
HW Convergence
INLET CONTROL DATA ...
Equation form
Inlet Control K
Inlet Control M
Inlet Control c
Inlet Control Y
Tl ratio (HW/D)
T2 ratio (HW/D)
Slope Factor
unsubmerged inlet control Form
submerged inlet control Form
2
1 .5000
276.30
276 .15
26 .00
26 .00
.00577
. 0130
.5000
. 018213
1 .0000
.001
1
.0098
2 .0000
.03980
. 6700
1 .157
1 .304
-.500
1 equ.
1 equ.
In transition zone between unsubmerged and
interpolate between flows at Tl & T2 ...
At Tl Elev 278 .04 ft ---> Flow
At T2 Elev= 278.26 ft ---> Flow
ft
ft
ft
ft
ft
ft/ft
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/-ft
below Tl elev .
above T2 elev .
submerged inlet control ,
7 .58 cfs
8 .66 cfs
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02 -21-2007
y
yyyType .... Outletyinput Data
yyyName .... DA6 -0UTLET
yyyFile .... H:\ENGINE-l\CRESCE-l\DRAINAGE\PPK-TMP\DA6 .ppk
OUTLET STRUCTURE INPUT DATA
Structure ID
Structure Type
# of Openings
Crest Elev.
Weir Length
Weir Coeff .
Weir TW effects
Structure ID
Structure Type
Weir-Rectangular
1
278.10 ft
100 .00 ft
3 .000000
(Use adjustment equation)
= TW
= TWySETUP ,yDS Channel
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 30
Min . TW tolerance .01 ft
Max . TW tolerance .01 ft
Min . HW tolerance .01 ft
Max . HW tolerance .01 ft
Min . Q tolerance .10 cf s
Max. Q tolerance .10 cf s
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yPage 3.03
yyyPond Pack Ver : 8-01 -98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02-21-2007
y
yyyType .... Composite Rating Curve
yyyName .... DA6 -0UTLET
yyyFile .... H:\ENGINE-l\CRESCE-l\DRAINAGE\PPK-TMP\DA6 .ppk
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
Elev . Q
ft cfs
276.30
276 .80
277 .30
277 .80
278 .10
278 .30
278 .50
.00
1 .56
5.65
11. 44
15 .35
44.54
95 .30
TW Elev
ft
Converge
Error
+/-ft
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Free Outfall
Contributing Structures
None contributing
yyyS/N : HOMOL0132809 Kling Engineering & Surveying
yPage 3 .04
yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 14 :47 :31 yyyDate : 02 -21-2007
y
yyyType .... Pond Routing Summary
yyyName .... DA6 -POND OUT yTag : 25 YR
yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DA6.ppk
yyyStorm ... 25 YR yTag : 25 YR
HYG Dir
Inf low HYG file
Outflow HYG file
Pond Node Data
Pond Volume Data
Pond Outlet Data
No Infiltration
INITIAL CONDITIONS
Starting ws Elev
Starting Volume
Starting Outflow
Starting Infiltr .
LEVEL POOL ROUTING SUMMARY
H:\ENGINE-1 \CRESCE-1\DRAINAGE\PPK-TMP\
NONE STORED -DA6-POND IN 25 YR
NONE STORED -DA6-POND OUT 25 YR
DA6 -POND
DA6 -POND
DA6 -0UTLET
276 .30
.000
.00
.00
ft
ac-ft
cfs
cfs
Starting Total Qout= .00 cfs
Time Increment .0222 hrs
INFLOW/OUTFLOW HYDROGRAPH SUMMARY
Peak Inflow
Peak Outflow
Peak Elevation
Peak Storage =
MASS BALANCE (ac-ft)
+ Initial Vol
+ HYG Vol IN
-Infil tration
-HYG Vol OUT
-Retained Vol
Unrouted Vol
22 .77 cfs
10 .08 cfs
277 . 68 ft
.257 ac-ft
.000
.486
.000
.486
.000
at
at
.1776 hrs
.3552 hrs
-.000 ac-ft (.008 % of Inflow Volume)
yyyS/N: HOMOL0132809 Kling Engineering & Surveying
yPage 4 .01
Event : 25 YR
yyyPond Pack Ver : 8-01 -98 (61 ) yyyCompute Time : 14 :47 :31 yyyDate : 02-21-2007
y
YYYAppendix A
Index of Starting Page Numbers for ID Names
-----D
DA-6-PST-25 25 YR ... 1 .01
DA6-0UTLET ... 3 .01 , 3 .04 , 2 .01 ,
4 .01
YYYS/N : HOMOL0132809 Kling Engineering & Surveying
A-1
YYYPond Pack Ver : 8-01 -98 (61) yyycompute Time : 14 :47 :31 yyyoate : 02-21-2007