HomeMy WebLinkAboutDetention Pond No2 AnalysisDetention Pond No. 2 Analysis
for
Dove Crossing Subdivision
Phase 8
College Station, Texas
May,2007
Developer:
Dove Crossing Development; LLC
1401 Sebesta Road
College Station, TX 77841
(979) 693-6699
Prepared B1 ·:
Civil Development, Ltd.
2033 Harvey Mitchell Parkway Sou th
Col1 ege Station. Texas 77840
(979) 7()4-7743 '
CERTIFICATION
I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Texas, certify that this
analysis for the Detention Pond No. 2 design for the Dove Crossing Subdivisioll -Pltase 8, was
prepared by me in accordance with the provisions of the City of College Station Drainage Policy
and Design Standards for the owners hereof.
~ l(;~
G -;;;{5 , P.E.
TABLE OF CONTENTS
DETENTION POND NO. 2 ANALYSIS
DOVE CROSSING SUBDIVISION -PHASE 8
CERTIFICATION ................................................................................................................................................................. I
TABLE OF CONTENTS ....................................................................................................................................................... 2
LIST OF TABLES .................................................................................................................................................................. 2
INTRODUCTION .................................................................................................................................................................. 3
GENERAL LOCATION AND DESCRIPTION ................................................................................................................. 3
FLOOD HAZARD INFORMATION ................................................................................................................................... 3
DEVELOPMENT DRAINAGE PATTERNS ...................................................................................................................... 3
DRAINAGE DESIGN CRITERIA ....................................................................................................................................... 3
STORM WATER RUNOFF DETERMINATION -DETENTION PONDS .................................................................... 5
DETENTION POND DESIGN .............................................................................................................................................. 5
CONCLUSIONS ..................................................................................................................................................................... 6
APPENDIX A ......................................................................................................................................................................... 7
Detention Pond No. 2 Design Data & Ca/culations7
APPENDIX B ........................................................................................................................................................................ 12
Detention Pond No. 2 Post-Development HEC-1 Output
EXHIBIT A ........................................................................................................................................................................... 23
Po st-Development Drainage Area Map -Detention Pond
LIST OF TABLES
TABLE 1 -Rainfall Intensity Calculations ................................................................................................. 4
TABLE 2 -Time of Concentration (tc) Equations ..................................................................................... 4
TABLE 3 -Pre-& Post-Development Drainage Area Data -HEC 1 ........................................................ 5
TABLE 4 -Drainage Area Parameters Summary -Detention Pond No. 2 Desi gn ................................... 6
2
DETENTION POND NO. 2 ANALYSIS
DOVE CROSSING SUBDIVISION -PHASE 8
INTRODUCTION
The purpose of this report is to provide the hydrological effects of the construction of Detention
Pond No. 2 of the Dove Crossing Subdivision -Phase 8, and to verify that the proposed
detention facility meets the requirements set forth by the Ci ty of Co llege Station Drainage Policy
and Design Standards.
GENERAL LOCATION AND DESCRIPTION
The project is located on a portion of a 97.94 acre tract located south of Graham Road west of
State Highway 6 in College Station, Texas. This report addresses Phase 8 of this subdivision,
which is made up of 10.95 acres. The site is predominantly open space with a few scattered
mesquite trees. The existing ground elevations range from Elevation 289 to Elevation 300. The
general location of the project site is shown on the vicinity map in Ex hibit A.
FLOOD HAZARD INFORMATION
The project site is located in the Lick Creek Drainage Basin. No portion of this property is within
a flood hazard area according to the Flood Insurance Rate Map prepared by the Federal
Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated areas
dated February 9, 2000, panel number 48041C0201-D.
DEVELOPMENT DRAINAGE PATTERNS
Prior to development of the subdivision, the storm water runoff for Phase 8 flowed in a southerly
direction across future phases of development of this subdivision until it leaves the property and
enters the South Fork of Lick Creek on the adjacent tract, which ultimately flows into Lick
Creek. Two detention ponds were constructed with previous phases of this subdivision, and the
runoff from Phase 8 flows into Pond 2 shown on Exhibit A, "Drainage Area Map, Post-
Development, Detention Pond."
DRAINAGE DESIGN CRITERIA
The design parameters for the detention facility analysis are as follows :
• The Rational Method is utilized to detennine peak stom1 water runoff rates for the stom1
sewer design, and the HEC-1 computer program is utili zed to determine peak stom1 water
runoff rates for the design of the detention ponds.
• Design Stom1 Frequency
Detention pond analysi s 5, l 0, 25, 50 and 100-year storm events
• Runoff Curve Number (CN) -Detention Ponds
The Brazos County Soil Survey shows the soils in the area to be classified as hydrologic
Group D soils. The pre-development CN is based on no development on the site. The
· post-development CN is based on development of Phases I , 2, 3, 4 & 8 of the subdi vi sion
within the detention pond drainage areas. The CN calcu lati ons are found in Appendi x D.
• Rainfall Intensity equations and valu es for Brazos County can be found in Table 1.
• Time of Concentration, tc -Calculations are based on the method found in th e TR-55
publication. Refer to Table 2 for the equations and Appendix A for calculations. The runoff
flow paths used for calculating the post-development times of concentration for the detention
pond analysis are shown on Exhibit B (refer to Phase 1 Drainage Report for pre-development
infom1ation), and the flow path used for the post-development times of concentration for the
stom1 sewer design is found on Exhibit A. For smaller drainage areas, a minimum tc of 10
minutes is used to determine the rainfall intensity values.
TABLE I -Rainfall Intensity Calculations
Rainfall Intensity Values (in/hr)
Storm tc =
Event 10 min
1, 7.693
110 8.635
125 9.861
lso 11 .148
1100 11 .639
Brazos County:
51:::ear storm 10 1:::ear storm
b = 76 b= 80
d= 8.5 d= 8.5
e= 0.785 e= 0.763
I = b I (tc+d)e
I = Rainfall Intensity (in/hr)
tc = U(V*60)
le = Time of concentration (min)
L = Length (ft)
V = Velocity (ft/sec)
25 1:::ear storm 50 1:::ear storm 100 1:::ear storm
b= 89 b= 98 b= 96
d= 8.5 d = 8.5 d= 8.0
e= 0.754 e = 0.745 e= 0.730
(Data taken from State Department of Hiqhwa1:::s and Public Transportation H1:::drau/ic Manual, page 2-16)
TABLE 2 -Time of Concentration (tc) Equations
Th e time of concentration was determined using methods found in TR -55, "Urb an
Hydrology for Small Watersheds. " The equations are as follows:
Time of Concentration:
For Sheet Flow:
For Shallow Concentrated Flow:
Refer to Appendix A for calculations.
Tc= T1(shee1 flow)+ T1(concen1ra1ed shcel flow)
where: T1 =Travel Time, minutes
where: T1 =travel time, hours
n =Manning's roughness coefficient
L = flow length, feet
P2 = 2-year, 24-hour rainfall = 4.5"
s = land slope, ft/ft
T1 = LI (60*V)
where: T1 =travel time, minutes
V =Velocity, fps (See Fig 3-1 , App. A)
L = flow length, feet
STORM WATER RUNOFF DETERMINATION -DETENTION PONDS
The peak runoff values were detem1ined in accordance with the criteria presented in the previous
sections for the S, 10, 2S, SO, and 100-year stom1 events. The drainage areas for the post-
development conditions for the detention pond analysis are shown on Exhibit A. Pre-
development and post-development runoff information for the detention pond is summarized in
Table 4. The pre-development drainages were shown on Exhibit B of the Phase I Drainage
Report.
TABLE 3 -Pre-& Post-Development Drainage Area Data -HEC I
Area le Lag Area# CN (acres) (sq. mi.) (min) (hrs)
Pre -105 27.96 0.0437 75.0 32.0 0.320 ---------------·----·-
Post -305 40.32 0.0630 83.4 39.0 0.390
DETENTION POND DESIGN
The development of this tract will increase the runoff due to the increase in impervious surfaces.
The drainage system for the development must be designed so that there is not an increase in the
peak runoff values at the locations where the runoff is discharged from this development. This
has been accomplished by the constrnction of two detention ponds. The proposed detention
ponds will serve Phases 1 thru 4 & Phase 8 of this development. The Developer has purchased
additional land to the south of this property to constrnct a pemianent detention facility for the
entire development.
Exhibit B in the Phase 1 Drainage Report shows the pre-development drainage area (Area l OS)
developed for this project, which flow into the detention pond. Exhibit A of this report shows
the post-development drainage area (Area 30S) for this phase of the project. The following
sections describe how the proposed drainage system for this project will control the runoff such
that the pre-development peak runoff values are not exceeded.
Detention Pond No. 2 -Drain age Areas 105 & 305
The location of the pond is shown on Exhibit A of this report. The proposed grading changes for
the pond are also shown on Exhibit A and the Grading Plan in the construction drawings. The
area-capacity data and the depth-discharge data for the pond are provided in Appendix A. The
detention pond grading plan is shown in the construction drawings.
The existing pond discharge pipe is a 42" HOPE pipe, SO feet in length. Rock riprap is located at
the discharge end to control erosion. The pipe has a design slope of O.S%, with the upstream
invert at Elevation 287.0. The to of the pond berm is at Elevation 292.S with a IO' top width
and SH: IV side slopes, with the overflow spi llway at Elevation 9 1.0 with a l O' bottom width
and SH: IV side slopes. 12" di ameter Pipes A & B have been added to allow discharge of the
runoff in Channels S & 6, which have flowlines lower than Elevation 287.0, the flowline of the
42" pipe. Due to the discharge through these pipes, the 42" pipe does not adequately control th e
peak runoff; therefore, a concrete outlet structure is being added to the upstream end of the 42"
pipe. The outlet structure is a concrete box structure with a 2.S' wide by 3' tall rectangular
opening with a flow line of 287.S.
The peak flow out of the detenti on pond was determined by the HEC-1 program using the depth
di scharge data for th e pond outlet structure as provided in Appendi x A. The area/capacity data
for the pond is inclu ded in Append ix A as well. 90% of th e available pond storage volume was
used fo r this analys is. As shown in Tabl e 4, the peak o utfl ow from the detenti on fac ility is less
than the all owable peak outflow fo r the design storm event. Additionall y, the tab le presents th e
max imum water surface in th e pond for each storm event, as well as th e amo unt of freeboard
provided.
TABLE 4 -Drainage Area Parameters Summary -Detention Pond No. 2 Design
Detention Pond 2
Pre-Development Area 105 Os 0 10 0 2s Oso 0 100
Post-Development Area 305 (cfs) (cfs) (cfs) (cfs) (cfs)
1 Pre-Development -Area 105 53 66 86 102 118
2 Post-Development without Pond -Area 305 96 11 4 143 164 185
3 Post-Development out of Pond 53 64 80 92 105
Decrease in Peak Runoff (Line 1 minus Line 3) 0 2 6 10 13
4 Max. Water Surface in Pond (ft) 290.2 290.5 290.9 291 .2 291.4
5 Top of Pond Berm 292.5 292.5 292.5 292.5 292.5
Freeboard (ft) (Line 5 minus Line 4) 2.3 2.0 1.6 1.3 1.1
The pre-development HEC-1 output data can be found in th e Phase I Drainage Report. T he post-
development HEC-l output is provided in Appendix B. The post-development flow and
maximum water surface are from this HEC-1 output.
CONCLUSIONS
The construction of this project w ill increase the storm water ru noff from thi s site. The proposed
storm sewer system should adequately control the runoff and release it into the detention ponds.
The proposed detenti on ponds should adequate ly contro l th e peak post-development runoff so
that it will not have any impact on the properti es downstream of this development. There is no
increase in runoff to the east onto the adj acent property due to the reduction in the drainage areas
fl owing to these areas after thi s development. There sho uld be no fl ood damage to downstream
or adjacent landowners resulting from this development.
APPENDIX A
Detention Pond No. 2 Design Data & Calculations
7
Dove Crossing Subdivision
Phases 1 -4 & 8
Detention Pond No. 2 Area-Capacity Data
V = H * {[A1+A2 + (A 1*A2)1'1/3}
V = volume, ft2
A= area, ft2
H = difference in elevation, ft
POND NO. 2
Elevation Depth Area
(ft) (ft) (ft2)
283.08 0.00 0 ·-------284.00 0.92 121 -·---------·-285.00 1.92 2,700
Area -Capacity Data
Area Volume Cumulative
Volume
(acres) (ac-ft) (ac-ft)
0.000 0.000 0.000 ·----------. ---0.003 0.001 0.001 -----------0.062 0.026 0.027
90 % Cumulative
Vo lume
(ac-ft)
0.000 -
0.001 --0.024 ·-·-----· ·---
286.00 2.92 6, 113 0.140 0.099 0.125 0.113 ------------·-· ---·---287.00 3.92 15,791 0.363 0.243 0.368 0.331 -··-------------288.00 4.92 35,313 0.811 0.572 0.940 0.846 -·-·---· -· ----------289.00 5.92 71690 1.646 1.000 1.940 1.746 -------------
290.00 6.92 130,577 2.998 2.288 4.228 3.805
. -----------------. 291 .00 7.92 185,805 4.265 3.613 7.841 7.057 -------------·--------· 292.00 8.92 258,956 5.945 5.082 12.923 11 .631
Dove Crossing Subdivision
Phases 1 -4 & 8
Pond 2 Elevation Discharge Data
12" Outlet Pipe A 12" Outlet Pipe B Outlet Structure2
42" Outlet Pipe 2.5' Wide Opening Elevation FL= 283.82 FL= 284.67 FL= 287.00 FL= 297.50
Depth Q Depth Q Depth Q Depth Q
(ft) (ft) (cfs) (ft) (cfs) (ft) (cfs) (ft) (cfs)
283.08 0.00 0.00 --------
284.00 0.12 0.10 ------ --
285.00 1.12 2.80 0.33 0.30 ----
286.00 2.12 4.90 1.33 3.20 -------287.00 3.12 6.00 2.33 5.10 ----0.00 0.00
----288.00 4.12 7.00 3.33 6.20 0.5 2.7 1.00 5.90 -~-------289.00 5.12 7.80 4.33 7.20 1.5 13.8 2.00 21.50 ---290.00 6.12 8.60 5.33 8.00 2.5 29.6 3.00 45.00 ---------291 .00 7.12 9.30 6.33 8.70 3.5 65.9 4.00 65.60
292.00 8.12 9.90 7.33 9.40 4.5 139.8 5.00 87.00
1. 1 O' bottom width with 5: 1 side slopes wi th a crest elevation of 291 .0, n=0.035.
2. Top of Outlet Structure= 290.5
3. Outlet Structure discharge exceeds 42" Pipe capacity.
Overflow Spillway 1 Total
Discharge
Depth Q
(ft) (cfs) (cfs)
----0.00
----0.10
----3.1 0
----8.10
----11.10
----15.90
----28.80
----46.20
----83.60
1.00 31 .00 137.30
Dove Crossing, Phases 1 -4 & 8
SCS Curve Number Calculations
Pond 2 -Post Development
Drainage Area -305
Area -Ac . 43.37
sq . mi. 0.0678
Tc = 27 .0
Lag = L = 0.6Tc = 16.2min= 0.27 hrs
Weighted
Land Use Area -Ac. CN II CN
Wooded-good
Pasture-good
Residential (1/8 acre)
Water
Total -CN II
Average Runoff condition CN =
CN I= 78 .8
ARC CN = CN I + 0.70(CN II -CN I)
1.27 77 2.3
4.49 80 8.3
37.26 92 79.0
0.35 98 0.8
43.37 90.4
86.9
APPENDIXB
Detention Pond No. 2 Post-Development HEC-1 Output
12
HECl S/N: 1 343001909 HMVersion: 6.33 Data File: C:\WINDOWS \TEMP\-vbh316A.TMP POST-DEVELOPMENT
***************************************** ***************************************
* * *
FLOOD HYDROGRAPH PACKAGE (HEC-1) * * U.S. ARMY CORPS OF ENGINEERS *
MAY 1991 * * HYDROLOGIC ENGINEERING CENTER *
VERSION 4.0.lE * * 609 SECOND STREET *
* * DAVIS, CALIFORNIA 95616 *
RUN DATE 05/18/2007 TIME 07:52:57 * * (916) 756-1104 *
* * *
~~~************************************** ***************************************
x x xxxxxxx xxxxx x
x x x x x xx
x x x x x
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x x x x
x x x x x
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x
x
xxx
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: : : : : : : : : :
Full Microcomputer Implementation
by
Haestad Methods, Inc.
: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :
: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :
37 Brookside Road * Waterbury, Connecticut 06708 * (203) 755-1666
THIS PROGRAM REPLACES ALL PREVIOUS VERSIONS OF HEC -1 KNOWN AS HECl (JAN 73 ), HEClGS, HEClDB, AND HEClKW .
THE DEFINITIONS OF VARIABLES -RTIMP-AND -RTIOR-HAVE CHANGED FROM THOSE USED WITH THE 1973-STYLE INPUT STRUCTURE.
THE DEFINITION OF -AMSKK -ON RM-CARD WAS CHANGED WITH REVISIONS DATED 28 SEP 81. THIS IS THE FORTRAN 77 VERSION
NEW OPTIONS: DAMBREAK OUTFLOW SUBMERGENCE , SINGLE EVENT DAMAGE CALCULATION, DSS:WRITE STAGE FREQUENCY,
DSS :READ TIME SERIES AT DESIRED CALCULATION INTERVAL
KINEMATIC WAVE: NEW FINITE DIFFERENCE ALGORITHM
LOSS RATE:GREEN AND AMPT INFILTRATION
HEC-1 INPUT PAGE 1
LINE ID ....... 1 ....... 2 ....... 3 ....... 4 ....... 5 ....... 6 ....... 7 ....... 8 ....... 9 ...... 10
1 ID Dove Crossing Phase 1 -Post-Development
2 IT 1 300
3 IO 5 0
4 KK 305100
5 KM Drainge Area 305
6 KO 22
7 BA 0 .0678
8 PH 100 0 0 .88 1.95 4 .30 5.70 6.30 7.90
9 LS 86.9
10 UD 0.27
11 KK P2-100
12 KM Detention Pond 2 -100 year
13 KO 22
14 RS 1 ELEV 283 .08
15 SV 0 0.001 0 .024 0.403 0.331 0.846 1.746 3.80 5 7 .057 11.631
16 SE 283.08 284.0 285.0 286.0 287.0 288.0 289.0 290.0 291 .0 292.0
17 SQ 0 0.1 3.10 8.10 11.10 15 .90 28.80 46.20 83.60 137.30
18 SE 283.08 284.0 285.0 286.0 287.0 288.0 289 .0 290 .0 291.0 292 .0
19 KK 305-50
20 KM Drainage Area 305
21 KO 22
22 BA 0.0678
23 PH 100 0 0.81 1. 80 3.91 5.10 5.70 7.00
24 LS 86 .9
25 UD 0.27
26 KK P2-50
27 KM Detention Pond 2 -50 year
28 KO 22
29 RS 1 ELEV 283.08
30 SV 0 0.001 0.024 0 .403 0 .331 0 .846 1.746 3.805 7.057 11. 631
31 SE 283.08 284.0 285.0 286.0 287.0 288.0 289.0 2 90. 0 291.0 292.0
32 SQ 0 0 .10 3 .10 8.10 11 .10 15.90 28.80 46 .20 83.60 137.30
33 SE 283.08 284.0 285.0 286.0 287.0 288.0 289.0 290 .0 291.0 292 .0
34 KK 305-10
35 KM Drainage Area 305
36 KO 22
37 BA 0.0678
38 PH 10 0 0 .66 1.45 3.02 3.90 4 .30 5.20
39 LS 86.9
40 UD 0 .27
41 KK P2-10
4 2 KM Detention Pond 2 -10 year
43 KO 22
44 RS 1 ELEV 283 .08
45 SV 0 0 .001 0.024 0 .403 0 .331 0 .846 1.746 3.805 7.057 11.631
46 SE 283 .08 284 .0 285.0 286.0 287 .0 288.0 289.0 290.0 291.0 2 92. 0
47 SQ 0 0 .10 3 .10 8.10 11.10 15.90 28.80 46.20 83.60 137.30
48 SE 283 .08 284.0 285.0 286.0 287.0 288.0 289 .0 290.0 291.0 292.0
HEC-1 INPUT PAGE 2
LINE ID ....... 1. ...... 2 ....... 3 ....... 4 ....... 5 ....... 6 ....... 7 ....... 8 ....... 9 ...... 10
49 KK 305-25
50 KM Drainage Area 305
51 KO 22
52 BA 0.0678
53 PH 25 0 0 .74 1. 64 3.52 4.60 5.10 6.2 0
54 LS 86.9
55 UD 0.27
56 KK P2-25
57 KM Detention Pond 2 -25 year
58 KO 22
59 RS 1 ELEV 283.08
60 SV 0 0.001 0 .024 0.403 0.331 0.846 1.746 3 .805 7.057 11 .631
61 SE 283.08 284.0 285.0 286.0 287.0 288 .0 289 .0 290.0 291.0 2 92 . 0
62 SQ 0 0.1 3 .10 8.10 11.10 15.90 28.80 46.20 83.60 137.30
63 SE 283 .08 284.0 285.0 286.0 287 .0 288.0 289.0 290.0 291 .0 2 92. 0
64 KK 305-5
65 KM Drainage Area 305
66 KO 22
67 BA 0.0678
68 PH 5 0 0.60 1.32 2.68 3 .30 3 .70 4.40
69 LS 86.9
70 UD 0.27
71 KK P2-5
72 KM Detention Pond 2 -5 year
73 KO 22
74 RS 1 ELEV 283.08
75 SV 0 0.001 0.024 0.403 0.331 0.846 1.746 3.805 7.057 11.631
76 SE 283.08 284 .0 285.0 286.0 287 .0 288.0 289.0 290.0 2 91. 0 292 .0
77 SQ 0 0 .10 3 .10 8.10 11.10 15.9 28.8 46.20 83.60 137 .30
78 SE 283.08 284.0 285.0 286.0 287 .0 288 .0 289.0 290.0 291.0 2 92. 0
79 KK DP -2
80 KM Discharge Point No . 2
81 KO 22
82 HC 5
83 zz
HECl S/N: 1343 001909 HMVersion: 6.33 Data File: C:\WINDOWS \TEMP\-vbh316A.TMP
. ~4~~~•**********************************
FLOOD HYDROGRAPH PACKAGE
MAY 1991
VERSION 4.0.lE
(HEC-1 )
*
*
*
*
*
RUN DATE 05/18/2007 TIME 07 :52:57 *
*
~~··~************************************
Dove Crossing Phase 1 -Post-Development
IO
IT
OUTPUT CONTROL VARIABLES
IPRNT
I PLOT
QSCAL
HYDROGRAPH TIME DATA
5 PRINT CONTROL
0 PLOT CONTROL
0. HYDROGRAPH PLOT SCALE
NMIN 1 MINUTES IN COMPUTATION INTERVAL
IDA TE 1 0 STARTING DATE
I TIME 0000 STARTING TIME
NQ 300 NUMBER OF HYDROGRAPH
NDDATE 1 0 ENDING DATE
NDTIME 0459 ENDING TIME
I CENT 19 CENTURY MARK
COMPUTATION INTERVAL
TOTAL TIME BASE
0.02 HOURS
4.98 HOURS
ENGLISH UNITS
DRAINAGE AREA
PRECIPITATION DEPTH
LENGTH, ELEVATION
FLOW
STORAGE VOLUME
SURFACE AREA
TEMPERATURE
SQUARE MILES
INCHES
FEET
CUB IC FEET PER SECOND
ACRE-FEET
ACRES
DEGREES FAHRENHEIT
ORDINATES
***************************************
* *
* U.S . ARMY CORPS OF ENGINEERS *
* HYDROLOGIC ENGINEERING CENTER *
* 609 SECOND STREET *
* DAVIS, CALIFORNIA 95616 *
* (916 ) 756-1104 *
* *
***************************************
~~~ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
KK 3051 00 *
*
**************
6 KO OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
QSCAL 0. HYDROGRAPH PLOT SCALE
IPNCH 0 PUNCH COMPUTED HYDROGRAPH
IOUT 22 SAVE HYDROGRAPH ON THIS UNIT
ISAVl 1 FIRST ORDINATE PUNCHED OR SAVED
ISAV2 300 LAST ORD INATE PUNCHED OR SAVED
TIMINT 0.017 TIME INTERVAL IN HOURS
v.r-.Lur:: EXCEEDS TABLE IN LOGLOG 0.01667 0.01667 6.00000
~~* **k *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
ll KK
13 KO
**************
*
P2-100 *
* *
**************
OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
HYDROGRAPH PLOT SCALE QSCAL 0.
IPNCH
IOUT
ISAVl
ISAV2
TI MINT
0 PUNCH COMPUTED HYDROGRAPH
22 SAVE HYDROGRAPH ON THIS UNIT
1 FIRST ORDINATE PUNCHED OR SAVED
300 LAST ORDINATE PUNCHED OR SAVED
0.01 7 TIME INTERVAL IN HOURS
~·~ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
30 5-50 *
*
**************
~ 1 c'.O OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
QSCAL 0 . HYDROGRAPH PLOT SCALE
IPNCH 0 PUNCH COMPUTED HYDROGRAPH
IOUT 22 SAVE HYDROGRAPH ON THIS UNIT
ISAVl 1 FIRST ORDINATE PUNCHED OR SAVED
ISAV2 300 LAST ORDINATE PUNCHED OR SAVED
TIMINT 0 .017 TIME INTERVAL IN HOURS
~-ub EXCEEDS TABLE IN LOGLOG 0.01667 0 .01667 6 .00000
~*~ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
26 KK
2 8 KO
**************
* *
P2-50 *
*
**************
OUTPUT CONTROL
IPRNT
I PLOT
QSCAL
IPNCH
IOUT
ISAVl
ISAV2
TIMINT
VARIABLES
5
0
PRINT CONTROL
PLOT CONTROL
0. HYDROGRAPH PLOT SCALE
0 PUNCH COMPUTED HYDROGRAPH
22 SAVE HYDROGRAPH ON THIS UNIT
1 FIRST ORDINATE PUNCHED OR SAVED
300 LAST ORD INATE PUNCHED OR SAVED
0.017 TIME INTERVAL IN HOURS
·~· *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
3.J KK
36 KO
**************
*
* 305-10 *
* *
**************
OUTPUT CONTROL VAR IABLES
IPRNT 5 PRINT CONTROL
I PLOT
QSCAL
IPNCH
IOUT
ISAVl
ISAV2
TIMINT
0
0.
0
22
1
300
0 .017
PLOT CONTROL
HYDROGRAPH PLOT SCALE
PUNCH COMPUTED HYDROGRAPH
SAVE HYDROGRAPH ON THIS UNIT
FIRST ORDINATE PUNCHED OR SAVED
LAST ORDINATE PUNCHED OR SAVED
TIME INTERVAL IN HOURS
·--::::<CEEDS TABLE IN LOGLOG 0 .01667 0 .01667 6.00000
~~~ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
41 KK * P2 -10 *
*
**************
4 3 KO OUTPUT CONTROL
IPRNT
I PLOT
QSCAL
IPNCH
IOUT
ISAVl
ISAV2
TIMINT
VARIABLES
5
0
0.
0
22
1
300
0 .017
PRINT CONTROL
PLOT CONTROL
HYDROGRAPH PLOT SCALE
PUNCH COMPUTED HYDROGRAPH
SAVE HYDROGRAPH ON THIS UNIT
FIRST ORDINATE PUNCHED OR SAVED
LAST ORDINATE PUNCHED OR SAVED
TIME INTERVAL IN HOURS
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
4 9 KK * 305-25 *
**************
51 KO OUTPUT CONTROL VARIABLES
I PRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
QSCAL 0 . HYDROGRAPH PLOT SCALE
IPNCH 0 PUNCH COMPUTED HYDROGRAPH
IOUT 22 SAVE HYDROGRAPH ON THIS UNIT
ISAVl 1 FIRST ORDINATE PUNCHED OR SAVED
ISAV2 300 LAST ORDINATE PUNCHED OR SAVED
TIMINT 0.017 TIME INTERVAL IN HOURS
·,·.~~us EXCEEDS TABLE IN LOGLOG 0 .01667 0.01667 6.00000
.. ~ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
56 !<K * P2 -25
* *
**************
56 KO OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT
QSCAL
IPNCH
IOUT
ISAVl
ISAV2
TIMINT
0 PLOT CONTROL
0 . HYDROGRAPH PLOT SCALE
0 PUNCH COMPUTED HYDROGRAPH
22 SAVE HYDROGRAPH ON THIS UNIT
1 FIRST ORDINATE PUNCHED OR SAVED
300 LAST ORDINATE PUNCHED OR SAVED
0.017 TIME INTERVAL IN HOURS
~-· *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
64 KK * 305-5 *
* *
**************
6 6 KO OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
QSCAL 0. HYDROGRAPH PLOT SCALE
IPNCH 0 PUNCH COMPUTED HYDROGRAPH
IOUT 22 SAVE HYDROGRAPH ON THIS UNIT
ISAVl 1 FIRST ORDINATE PUNCHED OR SAVED
ISAV2 300 LAST ORDINATE PUNCHED OR SAVED
TIMINT 0.017 TIME INTERVAL IN HOURS
VALU E EXCEEDS TABLE IN LOGLOG 0 .01667 0 .01667 6.00000
~·* *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
**************
* *
71 KK P2-5 *
* *
**************
-~:o OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
I PLOT 0 PLOT CONTROL
QSCAL o. HYDROGRAPH PLOT SCALE
IPNCH 0 PUNCH COMPUTED HYDROGRAPH
I OUT 22 SAVE HYDROGRAPH ON THIS UNIT
ISAVl 1 FIRST ORDINATE PUNCHED OR SAVED
ISAV2 300 LAST ORDINATE PUNCHED OR SAVED
TIMINT 0.017 TIME INTERVAL IN HOURS
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
79 KK
81 KO
**************
* *
DP-2 *
* *
**************
OUTPUT CONTROL VARIABLES
IPRNT 5 PRINT CONTROL
!PLOT 0
QSCAL 0.
IPNCH 0
22
PLOT CONTROL
HYDROGRAPH PLOT SCALE
PUNCH COMPUTED HYDROGRAPH
SAVE HYDROGRAPH ON THIS UNIT !OUT
ISAVl
ISAV2
TI MINT
1 FIRST ORDINATE PUNCHED OR SAVED
300 LAST ORDINATE PUNCHED OR SAVED
0.017 TIME INTERVAL IN HOURS
RUNOFF SUMMARY
FLOW IN CUBIC FEET PER SECOND
TIME IN HOURS, AREA IN SQUARE MILES
PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF
OPERATION STATION FLOW PEAK AREA STAGE MAX STAGE
:) -~OUR 24-HOUR 72-HOUR
HYDROGRAPH AT 305100 247. 2.78 50. 50. 50. 0 .07
ROUTED TO P2-100 105. 3.25 41. 41. 41. 0.07
:29~.39 3 .25
HYDROGRAPH AT 305 -50 222 . 2.78 44. 44 . 44. 0 .07
ROUTED TO P2-50 92. 3.27 36. 36. 36. 0.07
29i .l6 3.27
HYDROGRA PH AT 305-10 161 . 2.80 30. 30. 30 . 0.07
ROUTED TO P2-10 64. 3.27 24 . 24. 24. 0.07
290 .~7 3 .27
HYDROGRAPH AT 305-25 196. 2.80 38. 38 . 38. 0.07
ROUTED TO P2 -25 80. 3 .27 31. 31. 31. 0.07
:90 .90 3.27
HYDROGRAPH AT 305-5 139. 2.80 24. 24. 24. 0.07
ROUTED TO P2-5 53 . 3.27 20. 20. 20. 0.07
290 .19 3.27
5 COMBINED AT DP-2 394. 3.27 152. 152. 152. 0 .34
-·· NORMAL END OF HEC-1 ***
EXHIBIT A
Post-Development Drainage Area Map -Detention Pond
23