Freeport NIP(7.6)-SY000801I
I
Storm Water Drainage and Detention Analysis
For
144 Acre Tract
Duke Freeport Addition
City of Coppell, Texas
Prepared for Duke-Weeks Corporation
I August, 2000
- Storm Water Drainage and Detention Analysis
For
'- 144 Acre Tract
Duke Freeport Addition
City of Coppell, Texas
- Prepared for Duke-Weeks Corporation
- August, 2000
_ Executive Summary
,_ The City of Coppell has know for some time that the area downstream of the 140-Acre
Tract (commonly known as the NCH Tract) has had problems with flooding. For this reason the
City has requested that upon development of this tract and it upstream neighbor, Champion
Properties, design a storm water conveyance system that will restrict flow to an undeveloped
condition for the 2, 5, and 100 year storm event. During the course of this analysis the Modified
Rational Method was used to determine the amount of storm water runoff that is produced. This
method utilizes the equation:
Q=Ci
Q = storm water runoff (efs)
,_ C = surface runoff coefficient (based on land use)
I = Intensity of a specific storm (in/hr)
A = land contributing (Acres)
The City of Coppell considers an undeveloped tract of land to have a mnoff~_ent ~
-- comparison to a developed light industrial tract having a runoff coefficient '0.~~ith this
information, quantities of water generated as well as quantifies of water that would be allowed to
~ discharge can be generated. By taking a specific storm event i.e. the 100 year storm event over
various durations a total amount of storage can be determined that will detain the water generated
-- f~ so that it may release at a rate equal or less that what would be under undeveloped conditions.
x,ff_?s~ ' Due to the layout of this tract of land, it was decided to utilize all track docks as detention ponds
-- and then discharge to the main detention pond that traverses the subject tract from the
easternmost portion of the tract to the west property line. In order to accurately model this effect
the design was broken into two parts.
In the first part of this design, the track docks were analyzed indetSendently of the entire
system. The City asked that if detention in the track dock areas was going to be utilized then the
following parameters must be met:
~' The maximum depth that may be used is one (1) foot.
i
'- ~' If the detention pond encroaches into the firelane than a maximum depth within the firelane
may be four (4) inches.
'- >' The maximum depth at emergency exits may be one (1) inch.
~' Emergency exits must be placed on two-hundred (200) foot intervals
Since the total volume that could be used in the dock areas was predetermined, the design
· - criterion used was to utilize as much volume in the dock areas without it overtopping the volume
given. This was achieved by using the 100-year storm event and varying the size of the outlet
,- structure so that the total volume used equaled the total volume available for each area. This
outlet structure was determined by taking various storm durations to calculate the controlling
,- event that would create the peak elevation. This was achieved by using a program called "Pond
Pack" which takes all the input data (storm event, area, outlet structure, and detention volume)
~ and generates an inflow as well as an outflow hydrograph. It should be noted that this approach
is consistent with the detention design method accepted by the City of Dallas. This report breaks
down all the track dock areas into individual reports showing the design storm event as well as
the outflow hydrographs they produce. Once all the outlet structures were determined for each
truck dock area, these numbers were used to determine the effects on the entire system.
The Second part of this design consisted of determining the size as well as the
configuration of the outlet structure of the main detention pond. The first part of this analysis
consisted of inserting the volumes as well as the calculated outlet structure openings for each
truck dock area. Once this was achieved, an estimated volume required was inserted into the
program. Next a normal water surface elevation was determined for each the 2,5, and the 100
storm event. From this point on_,the final analysis consisted of a trail and error approach in sizing
the pond as well as the outfall structure in order to allow a release rate equal to undeveloped
conditions for each of the three storm events used.
In conclusion the information presented in this report defines the flow characteristics of
the site plan as is shown in this report. It should be noted that any deviation from this site plan
would require recalculations in the actual storm water discharge from the contiguous 140 Acre
tract. This in part is due to the way each storm was routed through the system and the effects it
had on the detention pond.
ii
Table of Contents
Chapter I Southern Watershed
Introduction .............................................. 1
'" Truck Dock Areas ........................................ 1
DA 8 Detention Basin ................................... 3
'" Southern Detention Basin .............................. 4
Chapter H Northern Watershed
Truck Dock Area ........................................ 8
DA 11 Detention Basin ................................. 8
Northern Detention Basin .............................. 9
,- Chapter HI Conclusions and Recommendations
Summary ................................................. 10
iii
List of Tables
Table 1.1 (Drainage Area Design Results) .......................................... Al-1
Table 1.2 (Unit Hydrograph Ratios) ............................................... A2-1
... Table 1.3 (Southern Detention Pond Outfall Design) ............................. A3-1
Table 2.1 (Northern Detention Pond Outfall Design) ............................ A4-1
List of Appendices
Appendix (Southern Watershed Stage Storage Data) .............................. Al-1
Appendix (Southern Watershed Hydrographs) ..................................... A2-1
Appendix (Northern Watershed Stage Storage Data) ............................. A3-1
Appendix (Northern Watershed Hydrographs) ..................................... A4-1
V
Chapter I. Southern Watershed
Introduction
'" In order to analyze the drainage patterns of this site, certain items had to in place. This
included but was not limited to a conceptual site plan as well as a conceptual grading plan. Once
'- these items were agreed upon, drainage patterns could be determined. A drainage area map
(Figure 1-1) located on the following page will show the relationship of how the entire site will
--- drain as well as the hydraulic information for each drainage area. In the case of the southern
watershed (as well as the northern watershed) it was agreed upon that all track docks would be
,.. utilized as small detention ponds in an effort to detain as much before passing the storm water
generated down to the main detention pond. Since the volumes available in these track dock
areas were predetermined, the size of the outlet of each pond had to be determined in a way to
insure that the docks would not overflow during a specific storm event. In utilizing the Modified
Rational Method it was determined that the 20-minute, 100-year storm event would control the
size of the outlet structure in all the truck dock areas. This was determined by using a program
called "Pond Pack". By inputting the stage storage data of the ponds, the estimated outlet size,
and a given storm event into Pond Pack, it could be determined if the volume provided was
sufficient in handling the volume of water generated for that specific event. From this point a
trail and error approach was used to narrow down the size of outlet required for each track dock
area. By using Pond Pack the program would generate inflow as well as outflow hydrographs of
-- each truck dock. Once these hydrographs were determined the program would then combine
these graphs to determine the effects they have on the main detention pond. The design of the
-- main detention pond differed from the track dock areas in that the amount of water released was
predetermined and not the volume. By taking the outflow hydrographs of each contributing dock
-- area as well as the areas which were not detained, the volume needed as well as the outflow
structure of the main detention pond could be determined. The following subheadings will break
_ down the different drainage areas and discuss the specific design parameters of each area as well
as the results of the analysis.
Truck Dock Detention Analysis
The truck dock areas were designed in a way that would allow each site to detain as much
water on its respective site in efforts to minimize the size of the main detention pond. In previous
meetings with the City of Coppell it was decided that if detention in the track docks were going to
1
o. 1 o.~o I I I I I m~ ~
0.2 0.1~ GRAPHIC SCA~ IN FEET: 1"=200'
0,3 0.1~~ ~ ~A~ A~A
0.4 0.310
O.5
~ 0.~0
o.~ o.~o ~S~NG D~NA~ C~~ T~
0.~ o.g~
~9 0.~0
1.0 1.~ )R~NA~ ~EA C CA ~A Tc _lz ~ ~ I~ Q~~ (~h~our)h
, , (cf~)
1.2 0.930 EX DA ~A', 31.~ ~30 9.~ g.~ 4~ ~ 24.2 24.2 3.~ 2g.3 29.3 5.~ 47.447.4
1.3 ~0 EX DA ~ 13.7 0.~ 4.114.11 20 ~87 1~.9 l~.g 4.55 18.7 1B.7 G.g7 2~
1.~ 0.7~ EX DA (C]101.8 0.~ ~.~ ~.54 4~ ~ ~.g 77.g ~ 94.4 94.4 5.~ 1~2.7 152.7
1.5 0.680 EX DA (D~128.1 0.30~.~ 70.22 74 1~73 6~6 121.5 2~0 87.5 154.5 3.~ 141.3 2~.0
1.6 0.~0
1.7 0.~0
zo o4~o
2.2 0.207 ~NNA~ ~ Tc , I= ~ ~ ~
2.4 0.147 A~ ~) C (m~ut~)i(~r)._._) (In~r~ (c~)(in~r) (cfs)
2.6 0.107 ~P. ~01.~ ~ 43 2.~ ~.9 5.~ 94.4 5.0 152.7
2.~ 0.077 1 11.~ ~ 10 5.04 ~.4 5.~ 62.~ 8.~ ~4.0
5.0 0.~5 .~e~ ~ 7.51 ~ 10 5.~ ~.~ 5.~ 59.7 ~.~ 60.0
3.4 0.029 ~I ~ 1.28 ~99 10 5.~ 5,8 5.~ 6.8 8.~ 10.2
~.6 0,011 ~ i 7.1g [90 10 5.0~ ~2.6 5.~ ~.0 8.~ 57.5
3.8 0,015
~ ~ ~.95 0.~ ~o 5.~ ~7.9 5.~ 20.9 8.~
~.0 ~011 ~ p,]4 ~90 10 5. N ~7.8 5.~ ~.1 8.~ ~.7
4.5 0.,5 ~ ~ 7 19.~1 ,~ 10 5.~ ~.0 ~ 102.7 B.~ 155.1
5.0 0.~o a sT.s7 ~9o ~o 5.~ ~.7 5.~ 9~.o a.~ ~.4
a~~ 10 4.24 ~ 10 5.0~ 19.2 5.~ 2~.~ 8.~ ~.9
EXtS~NG 11 2.04 0.90 lO 5.~ 9.5 5.~ ~0.8 a.~ 16.5
~ 12 2.67 0.90 10 5.~ 12.1 5.~ 14.1 8.~ 21.3
13 2., 0., 10 5.04 l~Z 5., 15.4
~t 16 ~1.6 ~ 43 2.~ 24.2 5.~ 29.3 5.0 47.4
-
~IS 0~-~ DRNNA~ AR~ TAKEN
~ ~NNA~ ~EA M~ PR~AR~
BY: H~F A~O~S. INC. FOR
N~ ~P~A~. 140 A~E MAS~RP~N
DA~: APRIL 199B ~
EXIS~NO
O?~= 152.7 cf~
u
~~ ~DY
141.7 ACRE ~CT
--v-- e-- DU~E~RT ~D~N
~ P.~ ~/15/~. ~T ~s
be used then the following parameters be meet. First, the maximum depth that could be used is
one (1) foot. Secondly, an emergency exit is to be provided on two hundred (200) foot intervals
and that the maximum depth in those areas may be one (1) inch. Storage may include the
firelane, but that the maximum depth in the firelane may be four (4) inches. With these
parameters and the given site plan, the volumes to be used for Drainage Areas 3, 4, 7, 8, and 9
were determined. Located in Appendix A1 is a collection of drawings that break down each
drainage area, and shows the stage storage data as well as the hydraulic information for that
specific area. Once the volumes were determined, each track dock area was analyzed by using
-- Pond Pack. Pond Pack enables the user to input certain variables such as the area of each
drainage area, volume of the track docks, and an estimated orifice opening. Pond Pack then takes
'" this information and applies various storm events (in this case the 2, 5, and 100 year storms) as
defined by the user and calculates the inflow as well as the outflow hydrographs based on the
,'- effects the inputted data of each drainage area. The next part of this analysis was to then take the
same storms and drainage areas and run the model with various storm durations to determine
-- which of the storms would control the design of the outlet structure. The results of this analysis is
provided in Table 1-1 and shows the controlling event, the required opening size of the outlet
,_ structure, as well as the maximum flow generated that will leave the track dock areas at any given
time. The actual inflow and outflow hydrographs generated have been provided in Appendix A-2.
-- TABLE 1.1 - Drainage Area Design Results
Drainage Area Controlling Required Maximum Flow
Area Storm Duration Opening Generated
-- (Q~oo)
(Ac) (min) (ft2) (cfs)
3 10.72 20 8.50 43.69
-- 4 7.19 20 6.50 33.27
7 19.41 20 13.00 66,44
8 17,57 20 15.00 77.05
-- 9 13.10 20 8.80 45.67
DA 8 Detention Basin
In further efforts to minimize the size of the main detention pond another detention pond
was provided in Drainage Area 8. The purpose of this pond is to collect the water generated from
Drainage Area 7 and 8 truck docks. Located in Appendix Al-5 is a simple drawing which shows
the stage storage data used in the calculation of the required orifice opening area to insure that the
· --- 3
pond does not overtop. This basin was design much in the same way as the truck dock areas were
developed, but with one minor change. Where each truck dock was tested at various storm
durations to determine the required orifice opening, the detention basin took both DA 7 as well as
DA 8 at the same Storm Duration. What this means is that even though a 20 minute may have
controlled in the truck dock area, a longer storm may and did control the required outlet size of
the detention basin. During the course of this design it was determined that a 40 minute 100 year
required an orifice opening of 11.4 square feet. This opening would then generate a maximum
flow of 118.25 cfs at the peak of this storm. The inflow as well as the outflow hydrographs
generated for this area can be seen in Appendix A2-16.
Champions
In this report the land described as being "Champions" can be more particularly
described as being a 100-Acre Tract located West of the 140-Acre Tract. The Champions tract
drainage currently sheet flows onto the 140-Acre Tract at which point most of the storm water
generated is concentrated to a common discharge point located in the southeast comer of the 140-
Acre Tract. Part of the reason the southern detention pond was designed to span the width of the
140-Acre Tract, was to allow Champions a point of discharge onto this tract. Being that
Champions discharges directly into this system, it was prudent for this study to take their
discharge patterns into considerations. Through various conversations with Mr. Chuck Stark,
'- Vice President with Graham Associates, Inc. (Champions' Civil Engineer) Pacheco Koch was
able to obtain the exact acreage of their tract as well as the size of their detention pond. From this
~ information Pacheco Koch took Champions data and inputted their expected outflow hydrograph
into the southern watershed. To achieve a hydrograph consistent with the hydrographs generated
~ on the 140-Acre site, Pacheco Koch had to modify the design storm so that the methodology was
consistent throughout this analysis. Hydrographs generated for the Champions' site can be seen
,- in Appendix A2-19.
Southern Detention Basin
The last stage of this design was to determine the amount of volume that would be
required of the main detention pond as well as the size of the outlet structure. The sole purpose of
4
providing detention prior to reaching the main pond was in efforts to decrease the amount of
volume required. The analysis performed on the whole system varied from the design of the
individual truck dock areas in the following way. Previously each drainage area utilized the
methodology of the Modified Rational Method as is shown in the City of Dallas "Drainage and
Design Manuel". This method was acceptable for modeling the individual drainage areas due to
the fact that small drainage areas were being analyzed. Now that the system was being designed
as a whole, a better method was needed. Pacheco Koch took the approach of using a unit
hydrograph. The advantage of the unit hydrograph was that the same input variables could he
used, all that was changed was the rainfall distribution. This was achieved by taking a ratio of the
peak rainfall, which is based on the storm duration, from time index zero increasing the amount
of rainfall as to reach the peak, time index 1.0, then lagging the storm out five times the peak
time. The ratio used in this exercise can be seen in Table 1-2. As was done for the
TABLE 1.2 - Unit Hydrograph Ratios
Time Discharge Time Discharge
,_ Ratio Ratio Ratio Ratio
(t/tp) (q/qp) (tJtp) (q/qp)
0.0 0.000 1.7 0.460
,.-- 0.1 0.030 1.8 0.390
0.2 0.100 1.9 0.330
0.3 0.190 2.0 0.280
0.4 0.310 2.2 0.207
~ 0.5 0.470 2.4 0.147
0.6 0.660 2.6 0.107
0.7 0.820 2.8 0.077
~ 0.8 0.930 3.0 0,055
0.9 0.990 3.2 0.040
1.0 1.000 3.4 0.029
,-- 1.1 0.990 3.6 0.021
1.2 0.930 3.8 0.015
1.3 0.860 4.0 0.011
1.4 0.780 4.5 0.005
1.5 0.680 5.0 0.000
1.6 0.560
'- detention basin located in Drainage Area 8, the watershed was then analyzed as a whole. This
model was tested at various storm durations in order to determine which would control the
,--- design. It was determined that an 80-minute, 100-year event would control the volume required.
· -- 5
Now that the controlling storm was determined, the next part of this design entailed sizing the
outfall structure as well as the size of the detention pond.
The final part of this design was to determine the configuration of the outlet structure as
well as to determine the volume required. The results of this analysis can be seen in Table 1.3
below. First, an estimated volume as well as an estimated outlet opening was inputted into Pond
TABLE 1.3 - Southern Detention Pond Outfall Design
Design Storm Orifice Invert Height Allowable Expected
Event Opening Elevation Discharge Discharge
'" (ft2) ft above NWSE (ft) (cfs) (cfs)
2 Year Event 16.0 0.00 1.0 121.5 121.68
5 Year Event 4.0 2.13 0.5 154.5 155.91
100 Year Event 6.0 2.78 0.5 250 247.51
Pack as well as the unit hydrograph for a 2-year storm event. The resulting data would show the
,_. maximum elevation that the pond would reach as well as the maximum flow that would leave the
site. By keeping the volume of the pond constant, the size of the outfall structure was varied in a
trail an error method until only the allowable discharge was leaving the site at any given time
(121.5 cfs). This was achieved by providing a sixteen square foot (16 sf) opening, one foot (1 fi)
in height. Now that the 2-year event was designed for the next item was to take into account the
5-year storm event. From the first part of this analysis it was determined that during a 2-year
rainfall event the maximum elevation the water ever reached was two feet, one and a half inches
(2.13 ft) above the normal water surface elevation. With this in mind, another opening with an
estimated opening size and an invert elevation just above the 2-year water surface elevation was
inputted into Pond Pack. From this point the 5-year unit hydrograph was inputted in to the
program in the same manner as the 2-year event was done. Once again, by keeping the volume of
-- the detention basin equal to that of the 2-year event, a trail an error approach was taken until it
was determined that a four square feet (4 sf) opening at a height ofhalfa foot (0.5') would only
-- allow 154.5 cfs to pass. The last storm taken into account was the 100-year event. Finally a third
opening was provided to account for the 100-year storm. This analysis was consistent with the
~ design of the other two openings in that the third openings invert elevation was placed just above
the 5-year storm water elevation, the volume used in the calculations stayed constant for each
,- evaluation, and that by varying the size of the opening the amount of water released could be
changed. The resulting data shows that if a six square foot (6 sf) opening that is half a foot (0.5')
in height the maximum discharge to leave this site is two hundred and forty seven cubic feet of
,-- 6
water per second (247 cfs) and a maximum height of four and a half feet (4.5') above normal
water surface elevation. Based on this final evaluation the stage storage data for the main
detention pond can be seen in Appendix Al-7 and Al-8. The resulting inflow and outflow
hydrographs are located in Appendix A2-22.
-- 7
Chapter II. Northern Watershed
,- Truck Dock Area
For thc Northern Watershed, the only Drainage Area that utilizes the truck docks for
detention is Drainage Area 14, which can be seen in Figure 1-1. Thc method of determining the
required outlet opening size was preformed which the same procedure as was done for the other
'- truck docks. The results showed that a 20-minute, 100-year storm would control the design
parameters to which the required opening could be calculated. Based on the stage storage data as
'" shown in Appendix A4-4, the openings required to prevent overtopping of the track dock area
have been determined to be nineteen square feet (19.0 sf) in opening size. The resulting outflow
,- hydrographs can be seen in Appendix A44.
'- DA 11 Detention Basin
Located in Drainage Area 11, a small detention basin was provided. Although the area
-- contributing to this detention basin is very small, the pond was designed so that it could detain the
contributing water to a point pass existing conditions in an effort to minimize the volume required
,- for the main detention pond. The design of this detention pond varied form the design in all of
the other detention ponds in that controlling factor was the size of the outlet structure and not the
,- required volume needed. It was determined that given the stage storage data, as can be seen in
Appendix A3-1, the required size of the outlet structure was a four inch (4 in.) pipe. Obviously a
four-inch pipe has a very good chance of clogging, therefore it was decided that at a minimum the
outfall structure would have an eight-inch (8 in.) outlet to provide a means of draining the pond.
With this in place the amount of water released from this pond could be determined, and can be
seen in the inflow and outflow hydrographs provided in Appendix A4-1.
· - 8
,_ Northern Detention Basin
... As was done for the Southern Detention Pond, the design of the outlet structure for the
Northern Detention Pond was designed so that it would only release at a rate equal to that of
,.. existing conditions. This was achieve by taking an estimated volume as well as an estimated
outlet opening, and then calculating by trial and error the required volume of the detention pond.
Please refer to Southern Detention Basin located in Chapter 1, to review the steps taken to
calculate this information. The results of these calculations can be found in Table 2.1 below.
TABLE 2.1 - Northern Detention Pond Outfall Design
"' Design Storm Orifice Invert Height Allowable Expected
Event Opening Elevation Discharge !Discharge
(ft2) ft above NWSE (ft) (cfs) (cfs)
"" 2 Year Event 2.2 0.00 1.0 15.9 15.77
5 Year Event 0.4 1.83 0.5 18.7 19.82
100 Year Event 0.5 2.40 0.5 28.8 29.00
· "- 9
Chapter III. Summary
The purpose of this study was to design a working drainage and detention plan for the
140-Acre Site. To achieve this, certain assumptions have to be made in order for this analysis to
be complete. This included first and foremost the overall site plan for this tract. As can be seen,
the layout of the site plays an integral role in the way this site drains. This is also especially key
in the roles the track docks plays in the overall system. Any changes made to the size, shape, and
lama
location of these docks would require reanalysis of the detention as well as the effects it would
have on the release rate of the main detention ponds. Due to the fact that the outfall structures
were designed for the 2, 5, and the 100-year storm, any changes to the site plan could effect the
release rates for the various storms that in mm would violate the set release rates agreed to by the
City of Coppell.
,- 10
Appendix A1
,' /,:",~,U ////"/,~x,~ / ~::~ u u - v -u ~ ~ ,--= ~ _-
o LOCATION MAP STAGE STORAGE DATA {
.J
a. n A=83,964 S~F EL=516.00 V=31,530 CF 0 50 100 200 300
EL=515.92 V=24~536 CF
~. A=48,200 ,...~7 0.2.3' EL=515.69 V=8,469 CF V=16,067 CF GRAPHIC SCALE IN FEET
~ A=27,447 SF ~ J 0.23' 'EL=515.46 V=6,918 CF V=9,149 CF
o-~' ~~ A=OSF ~ 0'2.3' EL=515.00V:3'782 CF V=O CF
'l
.~ PROPOSED DRAINAGE CALCULATION TABLE
e0' O .' -- ~'a--,',,-~l 9401 LBJ FREEWAY SUITE 300 DALLAS, TEXAS 75~43 972.235.3031
o ~~ DRAINAGE AREA Tc 12 Ot I~ O* Imo Omo
L~ AREA (ocres)" C (minutes) linch/hour) (cfs) linch/hour) (cfs) linch/hour) (cfs) DRAINAGE AREA 3
r-~ ,
LOCATION MAP STAGE STORAGE DATA
A=45,982 SF EL=514.00 V=I 7,131 CF
A=40,356 .08' V=3,679 CF
EL=513.92 V=I 3,452 CF
V=8,691 CF 0 50 100 200 300
A=26,072 SF ~ ~ 0.23 £L=513.69 V=4,761 CF
A=14,586 SF ~ J 0.23 'EL=513.46 V=3,829 CF V=4,862 CF
A=5,894 SF ~ J 0.23' 'EL=513.23 V=2,897 CF V=1,965 CF GRAPHIC SCALE IN FEET
A:O SF 0.23' EL=513.00 V=1,965 CF V=O CF
PROPOSED DRAINAGE CALCULATION TABLE
DRAINAGE AREA Tc 12 Q 2 15 Q ~ I~00 Q too
AREA (acres) C (minutes) (inch/hour) (cfs) (inch/hour) (cfs) (inch/hour) (cfs)
,. 9401 LBJ FREEWAY SUITE 300 DALLAS, TEXAS 75243 972.~'35,3031
4 7.19 0.90 10 5.04 32.6 5.88 38.0 8.88 57.5
DRAINAGE AREA 4
~ 1 AUO 2000 20~2-00.127
I E
">' % STAGE STORAGE DATA
~ LOCATION MAP
~.i TOTAL VOLUME
~ ~ A=195,122 SF EL=514.00 V-72,525 CF
~- ~ ~'0.08' EL=515.92 .V=15,610 CF
I o A=170~744 V=56,915 CF
J.,_ a. A=109,192 SF ~ ~ 0.23' ' EL=513.69 V=20,518 CF V=36,397 CF 0 80 160 320 480
A=60,224 SF ~ J 0.23' EL=513.46 V=16,322 CF V=20,075 CF
V=12,131 CF GRAPHIC SCALE IN FEET
· '
~_ A=23,832 SF 0.23' EL=513.23 V--7~944 CF
~ A=O SF 0.23' EL=513.O0 V=7,944 CF V=O CF
;~, PROPOSED DRAINAGE CALCULATION TABLE
o~ ~o DRAINAGE AREA Tc 12 O 2 Is O 5 I~o0 O 100 9401 LBJ FREEWAY SUITE 300 DALLAS. TEXAS 78243 e75'.255.$031
AREA (acres) C (minutes) (inch/hour) (cf, s)(inch/hour) (cfs) (inch/hour) (cfs)
!'~ 7 19.41 0.90 10 5.04- 88.0 5.88 102.7 8.88 155.1 DRAINAGE AREA 7
I,u;';01
2052-00.127
·
0#~ #0: 2052--26
I I
r-- --3
STAGE STORAGE DATA
^=122152 SF [/=514.00 ¥=4§,344 CF
A=106,715 S'~ JO.08"'EL=515.92 V=9,772 CF V=35,572 CF
A=68r245 SF 0'23'~ EL=513.69 V=12,824 CF V=22r748 CF
A=37,640 SF ~ J 0.25"' EL--513.46 V=10,201 CF V=12,547 CF 0 50 100 200 300
A---14~895 SF 0.23'~- V=7,582 CF
EL=513.23 V--4~965 CF
0.23'~EL=513.00 V=4,965 Cf GRAPHIC SCALE IN FEET
A=O SF V--O CF
PROPOSED DRAINAGE CALCULATION TABLE
DRAINAGE AREA Tc 12 O 2 15 O ,5 1100 O 100
AREA (acres) C (minutes)(inch/hour) (cfs) (inch/hour) (cfs) (inch/hour) (cfs) DRAINAGE AREA 8
8 17.57 0.90 10 5.04 79.'~ 5.88 95.0 8.88 140.4 ,
2052-00.127
D~ #0:2052-26
i II
LI d II
° STORAGE
~° STAGE DATA
~ LOCATION MAP
o A=122152 SF EL=514.00 V=45,344 CF
:~ A=106~715 .08'
;= EL=51 ~.9;~ V=35~572 CF
~- A=68,245 SF ~ ~ 0.23' ~EL=513.69 V=12,824 CF V=22,748 CF
o_ A=37,640 SF J 0.2.3' EL=513.46 V=lO,201 CF V=12,547 CF 0 50 100 200 500
A=14~895 SF 0.25' ' EL=513.25 V--7.582 CF V--4,965 CF
A--O SF 0.23' [-L=513.00 V=4.065 CE V=O CF GRAPHIC 8CAKE IN FEE1
-~, PROPOSED DRAINAGE CALCULATION TABLE
.--~-,-.c : : : AREA (acres) C (minutes) (inch/hour) (cfs) (inch/hour) (cfs) (inch/hour) (cfs)
'~ 9 13.10 0.90 10 5.04 59.4 5.88 69.3 8.88 104.4 DRAINA GEI
OW6 #0:2052-26
I !
LOCATION MAP
, ~ STAOE STORA(~E DATA
o
--I
u_ a_ -T~ 0 40 80 160 240
A=27,203 SF EL=513,00 V--89~597 CF
A=24-,715 SF ~ ~.....~.00'1 V=25,949 CF
EL=512.00 V=63,648 CF GRAPHIC SCALE IN FEET
A=22~329 1.00' V=23,512 CF
EL=511.00 V=40~1.36 CF
- A=20,051 SF ~ 1.00't V=21,180 CF
EL=510.O0 V=18~956 CF
o, V=O CF
,... ~ A=17,882 SF ~ 1'00'I EL=509.O0 V=18,956 Cf
I
PW~ NO: 2052-26
I .
o STAGE STORAGE DATA
o TOTAL VOLUME
~ A=145 EL=512.00 V=540,006 CF
,3 ¢=139,633 CF
~0 LOCATION MAi~ A=153 EL=511.O0 V=400,373 CF
0
~ A=122,721 SF EL=510. O0 V=128,509 CF V=272,064 CF
'~ V=154,954 CF
I:= A=111,587 SF EL=509.00 V=117,110 CF
~- V--48~919 CF
o A--100~579 SF EL=508.00 V=106,055 CF
a. A=95,122 SF EL=507.50 V--48,919 CF V--O CF 0 50 100 200 ,300
PROPOSED DRAINAGE CALCULATION TABLE GRAPHIC SCALE IN FEET
· , DRAINAGE AREA Tc 12 O 2 15 O 5 I~00 O 100
~- AREA (acres) C (minutes) (inch/hour) (cf,s) (inch/hour) (cfs) (inch/hour) (cfs)
~ CHAMP. 101.8 0.30 43 2.55 77.9 3.09 94.4 5.0 152.7
o · 1 11.77 0.90 10 5.04 53.4 5.88 62.3 8.88 94.0
o-o
o ~ * 2 7.51 0.90 10 5.04 34.1 5.88 39.7 8.88 60.0
-" ~ 3 10.72 0.90 10 5.04 48.6 5.88 56.7 8.88 85.7
'-~ 5b 1.28 0,90 10 5,04 5.8 5.88 6.8 8.88 10.2
~ O ~1.01 LBJ FREEWAY SUITE 300 DALLAS, TEXAS 76243 972.236.3031
oO~
:: : : :c : : : 4 7.19 0.90 10 5.04 ,52.6 5.88 58.0 8.88 57.5
~ 6 8.,:34 0.90 10 5.04 37,8 5.88 44.1 8.88 66.7 SOUTH DETENTION (WEST)
6 *-DENOTES THAT DA 2 IN THE TABLE IS THE COMBINATION OF BOTH EAST AND WEST DETENTION PONDS.
~o cae C~ 1"-100' AU(~ 2000 2052-00.127
o
o.~ ,¥0:2052-26
STAGE STORAGE DATA
LOCATION MAP
A=126,564 ~SF ~. EL=512.00 V=491,797 CF
~ 1~'' V=369~144 CF
A=118~784 S EL=511.00 V=122,653 CF
'- V=114,925 CF
A=111,109 EL=510. O0 V= 254.,219 CF
A=103,542 SF ~ 1.00' EL=509.00 V=107,303 CF V=146,916 CF 0 30 60 120 180
A=96~092 SF ~ J 1.00" ~EL=508.00 V=99,795 CF V=47,125 CF
A=92,412 SE ~ J 0.5, ', -EL=507.50 V=47,123 CF V=O CF GRAPHIC SCALE IN FEET
PROPOSED DRAINAGE CALCULATION TABLE
DRAINAGE AREA Tc 12 Q 2 15 O 5 I~00 O too
AREA (acres) C (minutes) (inch/hour) (cfs) (inch/hour) (cfs) (inch/hour) (cfs) ~o~ LB) FREEWAY SUITE 300 DALLAS. TEXAS 75243 e72,236.3031
* 2 7.51 0.90 10 5.04 34.1 5.88' 59.7 8.88 60,0sOUTH DETENTION (EAST)
10 4.24 0.90 10 5.04 19.2 5.88 22.4 8,88 33.9
*-DENOTES THAT DA 2 IN THE TABLE IS THE COMBINATION OF BOTH EAST AND WEST DETENTION PONDS. C~EI I1'-60' I AUG 2000 I 2052-00.127
D#~ #0:2052-26
Appendix A2
['
Southern Watershed
Drainage Area # ~
C =0.9
- A = 10.72 Acres
The 2, 5, and 100-year storms were modeled in this exercise.
20 Minute Storm Duration Controlled orifice size.
· Orifice opening of 8.5 square feet total required to prevent overtopping dock detention
Hydrograph
POND1 OUT $ yr
/
\ Currently Plotted Curves
~ POND1 O~ 5 yr
0 ~0 20 ~ ~ ~
~me (min)
Hydrograph
POND1 OUT 100 yr
50'
40' /" ........................................ '"''""r Currently Plotted Curves
// POND1 IN 100 yr
-- 30' POND1 OUT 100 yr
0 10 20 30 40 50 60
'13me (min)
Elev. vs. Time
POND1 OUT 100 yr
515.8
515.6 Currently Plotted Curves
' POND1 OUT 100 yr
515.4 -- POND1 OUT 5 yr
515.2
515'00 10 20 30 40 50 60
· me (min)
Volume vs. Time
POND1 OUT 5 yr
Currently Plotted Curves
15000 POND1 OUT 100 yr
POND1 OUT 2 yr
POND1 OUT 5 yr
10000
O0 10 20 ~ 40 50 ~0
'~m~ (rain)
.62-3
Drainage Area # 4
D~sign Pm~unctcrs
C = 0.9
· A-- 7.19 Acres
The 2, 5, and 100-year storms were modelod in this exercise.
· 20 Minute Storm Duration Controlled orifice size.
· Orifice opening of 6.5 square feet total required to prevent overtopping dock detention
Hydrograph
DA 4DO(l( OUT 2 yr
V- o //
0 ~0 20 ~ 40
A2-4
I-Iydrograph
DA 4DOCK OUT 5 yr
25
15 DA 4DOCK IN 5 yr
F ,, DA 4DOCK OUT 5
yr
0 : : '
0 ~0 20 30 40 50
· me (m~.)
Hydrograph
Currently Plotted
DA 4DOCK OUT 100 yr
0 10 20 ~ 40 ,50
~im~ {rain)
A2-$
Elev. vs. Time
DA 4DOCK OUT 100yr
513.8
513.6 Currently Plotted Curves
DA 4DOCK OUT 100 yr
513.4 DA 4DOCK OUT 2 yr
DA 4DOCK OUT 5 yr
513.2
513.0
0 10 20 30 40 50
Time (rain)
Volume vs. Time
DA 4DOC~ OUT 100yr
Currently Plotted Curves
1O00O
'
' DA 4DOCK OUT 100 yr
DA 4DOCK OUT 2 yr
-- DA 4DOCK OUT 5 yr
0 10 20 30 40 50
~me (rain)
A2-6
Drainage Area # 7
Design Psxameters
C = 0.9
A = 19.41 Acres
The 2, 5, and 100=year storms were modeled in this exercise.
20 Minute Storm Duration Controlled orifice size.
Orifice opening of 13.0 square feet total required to prevent overtopping dock detention
Hydrograph
DA7 DOCK OUT 2 yr
F DA7 DOCK IN 2 yr
~. / DA7 DOCK OUT 2 yr
0 10 20 30 40 50 60 70
F ~me (min)
A2-7
Hydrograph
DA?DOCK 0UT $ yr
Currently Plotted Curves
DA7 DOCK IN 5 yr
-- DA7 DOCK OUT 5 yr
0
0 10 20 30 40 50 60 70
Time (min)
Hydrograph
DA7 DOCK OUT 100 yr
[,
-' DA7 DOCK IN 100 yr
DA7 DOCK OUT 100 yr
.... ' '~""--~ '--~ I I I
0 10 20 30 40 50 60 70 80
'lime (min)
Eiev. vs. Tim~
DA7 DOCK OUT 2 yr
513.8
Currently Plotted Curves
/ / ~\ \ ~,.., ~:,( o~, ~oo yr
513.2
513.0
0 10
~me (min)
Vol~ vs. T~
DA?~ O~l~yr
DA7 D~K O~ 5 yr
0
0 ~0 20
am. (rain)
Drainage Area # 8
Desi_en Parameters
· C = 0.9
· A-- 17.57 Acres
Thc 2, 5, and 100-year storms were modeled in this exercise.
· 20 Minute Storm Dm'afion Controlled orifice size.
· Orifice opening of 15.0 square feet total required to prevent overtopping dock detention
Hydrograph
DA 8DOCK OUT 2 yr
DA 8 DOCK IN 2 yr
-- DA 8 DOCK OUT 2 yr
7/,,,,
F 0 ' ~
0 ~0 20 ~ ~
Hydrogmph
DA 8DOCK OUT 5 yr
~ 40 Currently Plotted Curves
" DA 8 DOCK OUT 5 yr
/
0 I I I I I ~' I~''' '""-11 I --i--
0 40 20 30 40 50
~me (rain)
Hydrogmph
DA 8DOCK OUT 100yr
F
_ . / ~ DA 8 DOCK IN 100 yr
I I I 9 I I ....... 1-~' M-~ I
0 10 20 30 40
Ttme (min)
Elev. vs. Time
DA 8 DOCK OUT 100yr
513.fl
513.6 Currently Plotted Curves
DA 8 DOCK OUT 100 yr
513.4 DA 8 DOCK OUT 2 yr
DA 8 DOCK OUT 5 yr
513.2
513.1~
0 10 20 30 40 50
'nme (min)
Volun~ vs. Time
DA 8DEr OUT2yr
I-
F ~ Z currently Plotted Curves
~ DA 8 DOCK OUT 100 yr
F DA 8 DOCK OUT 2 yr
~ DA 8 DOCK OUT 5 yr
0 10 20 30 40 50
· nme (rain)
Drainage Area # 9
Design Parameters
· C = 0.9
· A-- 13.10 Acres
· The 2, 5, and 100-year storms were modeled in this exercise.
· 20 Minute Storm Duration Controlled orifice size.
· Orifice ope~ng of 8.8 square feet total required to prevent overtopping dock detention
Hydrogmph
DA9 DOCK OUT 2 yr
~ ~0 \~ Currently Plotted Curves
' DA9 DOCK IN 2 yr
DA9 DOCK OUT 2 yr
'10~~___~
o
0 10 20 :30 40 ,50 ~0
E 'lime (min)
Hydmgmph
DA9 DOCK OUT 5 yr
~0 ×' ~ Currently Plotted Curves
-- DA~ DOCK 0~ 5
~ O0 ~0 ~ ~ ~ ~
l~m~ {rain)
Hydrograph
DA9DOCK OUT 100 yr
Currently Plotted Curves
~40 %,,..% DA9 DOCK IN 100 yr
\
0
0 10 20 30 40 50 60 70
~me (rain)
Elev. vs. Time
DA9 DOCK OUT 2 yr
DA9 DOCK OUT 100 yr
DA9 DOCK OUT 2 yr
513.0
0 10 20 30 40 50 60 70
Time (min)
Volume vs. Time
DAgDOCK OUT 100yr
Currently Plotted Curves
=~ DA9 DOCK OUT 100 yr
DA9 DOCK OUT 2 yr
~ DA9 DOCK OUT 5 yr
0 10 20 30 40 50 60 70
· me (min)
Drainage Area # 8 - Detention Basin
D~si~n Parameters
The 2, 5, and 100-year storms were modeled in this exercise.
* 40 Minute Storm Duration Controlled orifice size.
· Orifice opening of 11.4 square feet total required to prevent overtopping detention pond
I-Iydrograph
DA 8DEl' OUT2yr
F ~ Currently Plotted Curves
_ 40
' DA 8 DET IN 2 yr
,, / DA 8 DET OUT 2 yr
0 " ; I I : I I I I I , , ; , ; t I I I I
F 0 10 20 :30 40 ~) EO 70 80 eO 100 110
'l~me (min)
Hydrograph
DEr OUT 5 yr
Currently Plotted Curves
' ' DA 8 DET IN 5 yr
DA 8 DET OUT 5 yr
I I'~ ~ I -
Hydrograph
DA 8DET OUT 100yr
Currently Plotted Curves
DA 8 DET IN 100 yr
~ DA 8 DET OUT 100 yr
F 0 20 40 60 80 !00 120
Time (min)
Elev. vs. Time
DA 8 DET OUT 2 yr
Currently Plotted Curves
~ .~.- ........... ~ DA 8 DET OUT 2 yr
DA 8 DET OUT 5 yr
0 20 ,10 C:~ 80 100 120
'nm~ ~min)
Volume vs. Tir~
DA 8 DET OUT 2 yr
Currently Plotted Curves
DA 8 DET OUT 100 yr
40000 DA 8 DET OUT 2 yr
DA 8 DET OUT 5 yr
o
0 20 40 60 80 1 O0 120
'lime (min)
Drainage Area "Champions"
Desima Paramet~s
· C=0.9
* A = 98.11 Acros
The and storms modeled in this exercise.
2,
5,
100-year
W~rf~
· 70 Minute Storm Duration Controlled orifice size.
, Multiple Orifices were modeled in so that the peak discharges for the 2, 5 and the 100 year
storm would release at existing conditions.
Hydrograph
POND CHAMP OUT 2 yr
150
Currently Plotted Curves
POND CHAMP IN 2 yr
POND CHAMP OUT 2 yr
0 100 2O0 :300 400 fi00 600
T, me (min)
A2-19
Hydrograph
POND CHAMP OUT $ yr
Currently Plotted Curves
100 POND CHAMP IN 5 yr
~0~/// .... ~"..,,.,~,~ "'~'~'"~'~ POND CHAMP OUT 5 yr
0 ~--
Time (min)
Hydrograph
POND CHAMP OUT lOOyr
200 Currently Plotted Curves
POND CHAMP IN 100 yr
POND CHAMP OUT 100 yr
0 ~/ t I I I I ~--~ ~ I~ ~-~ I I I I I --
0 100 200 300 400 500 BO0 700
Time (rain)
Hey. vs. Time
POND CHAMP OUT 100yr
513
-- ~--" POND CHAMP OUT 2 yr
POND CHAMP OUT 5 yr
0 1~ ~ ~0 ~ ~ ~ 7~
· me (min)
Volume vs. Tim~
PONDCHAMP OUT 100yr
Currently Plotted Curves
POND CHAMP OUT 100 yr
POND CHAMP OUT 2 yr
POND CHAMP OUT 5 yr
100 200 300 400 500 600 700
'l~me (min)
Drainage Area "South Detention"
D~ign Pm'ame~ers
Multiple Orifices were modeled in so that the peak discharges for the 2, 5 and the 100 year
storm would release at existing conditions.
Hydrograph
SOUTH DET OUT 2 yr
150
E ~ 100 Currently Plotted Curves
SOUTH DET IN 2 yr
-- SOUTH DET OUT 2 yr
0 200 400 t300 800 1000 1200 1400
- 'ffm~ (min}
E Hydrograph
SOUTH DEl' OUT 5 yr
Currently Plotted Curves
SOUTH DET IN 5 yr
~ i~'~ 100 \i~, SOUTH DET OUT 5 yr
0 I I I I I I , , I I I I I I
0 200 400 ~ 800 1000 1200 1400
E Time (min)
Hydrograph
SOUTHDET OUT 100yr
SOUTH DET IN 100 yr
SOUTH DET OUT 100 yr
200 400 600 800 1000 1200 1400
Time (min)
Elev. vs. Time
SOUTHDET OUT 100yr
511
510 Currently Plotted Curves
' SOUTH DET OUT ~.00 yr
SOUTH DET OUT 2 yr
~)~ SOUTH DET OUT 5 yr
~ I I f I I , , I I I I I I
0 200 400 600 800 1000 1200 1400
'lime (min)
Volume vs. Time
SOUTH DEl' OUT 2 yr
~000000
600(X)0 Currently Plotted Curves
SOUTH DET OUT 100 yr
SOUTH DET OUT 2 yr
400000 SOUTH DET OUT 5 yr
0 : : I I I I , , , I I I I I I
0 200 400 600 800 1000 1200 1400
Time (min)
Appendix A3
RUB Y ROAD
§ I I[ 1I i I 11 1[ 1[ 1[ 1[
>, ~.-
~o LOCATION MAP STAGE STORAGE DATA
o
~ ~ A=170,732 SF EL=514.00 V=63,459 CF
~- ~ ~.._~_~ 0 " V=13,659 CF V=49,800 CF
o A--149,401 S .08'
, EL=51.3.92
a. n A=95,543 J 0'25'~' EL=513.69 V=17,952 CF V=31,848 CF 0 80 160 320 480
A=52,969 SF ~ J 0.25'~'EL=513.46 V=14,283 CF V=17,565 CF
I GRAPHIC SCALE IN FEET
" A=20,853 SF 0.23'~ EL=513.23 V=10,614 CF V=6r951 CF
- A=O SF 0.25"-EL=513.00 V=6,951 CF V=O CF
o'13
a~ PROPOSED DRAINAGE CALCULATION TABLE
'~ DRAINAGE AREA Tc 12 02 15 05 Iloo 010o
~ AREA (acres) C (minutes) (inch/hour) (~:fs) (inch/hour) (cfs) (inch/hour) (cfs) 1~401LBJFREEWAY SUITE,00 DALLAS. TEXAS?Sa43 072.235.3031
~ 14 23.00 0.90 10 5.04 10,4.3 5.88 121.7 8.88 183.8
,DRAINAGE AREA 14
z
D#~ NO: 2052-26
i~ LOCATION MAP
~ STAGE STORAGE DATA
a_~'n A=8,738 SF EL=513.00 V=19r026 CF 0 30 60 120 180
! A=5,544 SF 1.00' V=6,297 CF
EL=511.O0 V=4,833 CF GRAPHIC SCALE IN FEET
" 1'00'I 'EL=510. O0 V=4,853 CF
r-- A=4-,155 SF V=O CF
C~
a~ PROPOSED DRAINAGE CALCULATION TABLE
e4 Q2 15 Q5 1100 Q~oo
~ DRAINAGE AREA Tc 12
AREA (acres) C (minutes) (inch/hour) (cfs) (inch/hour) (cfs) (inch/hour) (cfs) ~0~ LBJ FREEWAY SUITE 300 DALLAS. TEXAS 75243 g72.23§.3031
"'--"-'~= ": ' 11 2.04 0.90 10 5.04- 9.3 5.88 10.8 8,88 16.3 DRAINA GE A
0#~' #0:2052-26
mm
~ STAGE STORAGE DATA
o~0 LOCATION MAP TOTAL VOLUME
A=114~257 SF EL=513.00 V=409~689 CF
:~ A=108,237 SF .00'
EL=512.00 V=298,456 CF
~- A=102,341 SF ~ ~ 1'00't EL=511.O0 V=105,275 CF V=193,181 CF
o
-J ~ 1.00't V=99,739 CF
o_ A=96,572 SF EL=510.O0 V=93,739 CF 0 50 100 200 300
A=90,934 SF ~ 1'00'I EL=509.00 V=93.739 CF V=0 CF
GRAPHIC SCALE IN FEET
o, PROPOSED DRAINAGE CAI,.CULATION TABLE
0-0 ·
R ~ DRAINAGE AREA Tc 12 e 2 15 Q s I~00 Q ~00
· 1 AREA (ocres) C (minutes) (inch/hour) (cfi) (inch/hour) (cfs) (inch/hour) (cfs)
2o 12 2.67 0.90 10 5.04 12il 5.88 14.1 8.88 21.3
o ~' 15 2.91 0.90 10 5.04 15,2 5.88 15.4 8.88 25.5
:~L~ 15 3.03 0.90 10 5.04 13~7 5.88 16.0 8.88 24.2 NORTH DETENTION
z 16 31.6 0.30 43 2.55 24~2 3.09 29.5 5.0 47.4
2052-00.127
~#~' NO: 2052-26
I
I
I
I
I
I
I
I
Appendix A4
!
!
!
!
!
!
I
!
!
!
I
NORTHERN WATER~I~D
Drainage Area # 11
Design Pm'amem's
C ~ 0.9
· A = 2.04 Acres
The 2, 5, and 100-year storms were modeled in this exercise,
80 Minute Storm Duration Controlled orifice size.
Orifice opening of 0.35 square feet total required to prevent overtopping dock detention
Hydrograph
DA llDEF OUT2yr
'~ Currently Plotted Curves
. DA 11 DET IN 2 yr
DA 11 DET OUT 2 yr
100 200 300
Time (min)
A4-1
Hydrogmph
DA 11DET OUT 5 yr
-- DA 11 DET IN 5 yr
[ , '~hN,~ ~ ..... DA 11 DET OUT 5 yr
0 100 200 300 400
'Brae (re}n)
F
Hydrogmph
F DA 11 DEr OUT 100yr
~.~ . , Currently ?lotted Curves
F 3' ,..,;~' "~..~. DA 11 DET IN 100 yr
,7' . '-,~ DA 11 DET OUT 100 yr
0 100 200 300 400
T~me (rain)
A4-2
Elev. vs. Time
DA 11DEF OUT 100yr
512.5
512.0
Currently Plotted Curves
511.5 DA 11 DET OUT 100
yr
~] DA 11 DET OUT 2 yr
511.0 DA 11 DET OUT 5 yr
510.5 '\ ,~ ~
510.0 ' ' '
0 100 200 300 400
'rime (min)
Volume vs. Time
DA 11 DEl' OUT 2yr
Currently Plotted Curves
~ DA 11 DET OUT 100 yr
DA 11 DET OUT 2 yr
~ DA 11DET OUT 5 yr
0
0 1~ 2~ 300 4~
~me (min)
A4-3
Drainage Area # 14
D~si_~n P~m~rs
· C =0.9
· A = 23.0 Acres
· Thc 2, 5, and 100-ye, ar storms w~rc modeled in this exercise.
· 20 Minuto Storm Duration Controlled orifice size.
· Orifice opening of 19.0 square feet total required to prevent overtopping dock detention
Hydrograph
DA 14DOCK OUT2yr
Currently Plotted Curves
40 DA 14 DOCK IN 2 yr
-- DA 14 DOCK OUT 2 yr
· ....... r~. [ I
0 10 20 ~0 40 50
A4-4
Elev. vs. Time
DA 14DOCK OUT 5yr
513.8
513.6 i Currently Plotted Curves
DA 14 DOCK OUT 100 yr
513.4 DA 14 DOCK OUT 2 yr
DA 14 DOCK OUT 5 yr
513.2 ~
513'00 10 20 30 40 50 60
33me (min)
Volume vs. T/me
DA 14D00[ OUT 100yr
50O00
Currently Plotted Curves
DA 14 DOCK OUT 100 yr
DA 14 DOCK OUT 2 yr
DA 14 DOCK OUT 5 yr
0 10 20 30 40 50 60
'13me (min)
A4-6
Drainage Area "North Detention"
F Des'_um Parameters
· The 2, 5, and 100-year storms were modeled in this exercise.
F · 80 Minute Storm Duration Controlled orifice size.
F
Hydrograph
NORTHDE-T OUT 2 yr
I~IORTH DE? OU~ 2 yr
10t17/ ~~' x\,x,'
0 200 400 000 800 q000 ~200 ~400
'~me (m~n)
A4-7
E Hydrograph
NORTH DET OUT 5 yr
[ ·
30 Currently Plotted Curves
NORTH DET IN 5 yr
u_ ~~~ NORTH DET OUT 5 yr
0 200 400 600 800 1000 1200 1400
'nme (min)
Hydrograph
NORTH DET OUT 100 yr
8O
~ Currently Plotted Curves
~ _~ 40 NORTH DET IN 100 yr
', ~ NORTH DET OUT 100 yr
0 200 400 600 800 1000 1200 1400 1600
Time (min)
A4-8
Elev. vs. Time
NORTH DET OUT 2 yr
512
Currently Plotted Curves
511 NORTH DET OUT 100 yr
NORTH DET OUT 2 yr
509 ; ; ; , , , I I I I 1
0 200 400 600 800 1000 1200 1400 1600
'nme (min)
Volume vs. Time
NORTH DEl' OUT .5 yr
Currently Plotted Curves
200000 NORTH DET OUT 100 yr
NORTH DET OUT 2 yr
NORTH DET OUT 5 yr
1OOOOO
o
0 200 400 600 800 1000 1200 1400 1600
'l'ime (min)
A4-9