HomeMy WebLinkAbout40 Williamsgate DrainageMay 29 , 2006
Mr. Mark Smith
P.O. Box 9960 1101 Texas Avenue
College Station, Texas 77842
Dear Mr. Smith:
\
Enclosed is a summary of the meeting which you arranged on May 24 , 2006
between the Haupt Family Partnership members and representatives for the
Williams gate Development. The purpose was to address concerns of the
Haupt Partnership about the run-off drainage as proposed by Williamsgate
and the change in storm water flow that has occurred since the
commencement of work on the Williams gate subdivision.
Included are the solutions to some of the problems and, also , the continuing
concerns held by the Haupt Partnership.
Again, our thanks to all who participated and our appreciation for your time
and suggestions .
Sincerely ,
~;_~;!~
Arrenia H. Ellis
Managing Partnership , Haupt Family Partnership
CC: Joshua Norton, Robbie Robinson, Wendell Rehm, Lee Adams
0)-'1
t /1.,Jo (
S-: (iO
111<
\..--"'-.
SUMMARY -MAY 24 , 2006 MEETING
PRESENT: Mark Smith and Joshua Norton, representing the City of
College Station; Wendell Rerun, Vice President, representing Robbie
Robinson LTD.; Lenwood Adams ofMDG; Arrenia (Reni) Ellis and
Florence King, representing the Haupt Family Partnership.
PURPOSE: To allow direct discussion between the concerned parties
concerning Storm Water Runoff from Williamsgate Subdivision onto the
property owned by the Haupt Family Partnership. This was initiated by a
telephone call to Mark Smith by Reni Ellis following commencement of
building activity (i.e., laying of sewage pipes) before an acceptable run-off
plan had been approved by the Partnership .
DISCUSSIONS:
Ellis expressed concern about the changed water flow pattern and excess dirt
it carries that currently occurs during rainfall and asked if Williams gate had
been granted a permit by TCEQ; Norton provided copies of their permits.
She stated that observations from outside the perimeter of Williams gate had
not shown a posting or maintenance of the NOI and that our experience with
the water flow and silting seems to indicate a lack of compliance with
regulations (SWP3). King showed and explained a series of dated
photographs she has made showing the new water flow pattern and excess
silt.
The question of a drainage path for run-off from Williams gate was
introduced by Ellis. The Partnership has rejected the proposal by
Williamsgate and the City for an easement for drainage to the east of the
existing houses into an existing stock tank. The natural drainage for the
Williamsgate property for the 50 years the Haupts have owned their acreage
has been through a ditch to the west of the houses. Experience with excess
water from the Strawn Water Lily operation has proven in the past that the
route selected by Williamsgate will be extremely detrimental to the land and
its value.
The following history of communication is to clarify the references to past
exchanges that were made during discussion:
..
1) Beginning on July 5, 2005 , Norton was told that the land could not
tolerate extra water at the point of release from the proposed retaining
pond onto the land east of the houses.
2) Telephone conversations with Robertson and with Mr. Gibbs , City of
College Station, included the same information.
3) At Ellis ' request, Gibbs sent a copy of the Williamsgate plat to Robert
Liesman, Vice President of Macina, Bose, Copeland and Associates , Inc .,
for his examination. This study indicated to Mr. Liesman that the
retaining pond was of insufficient size and needed to be doubled. Details
were included in his reply to Mr. Gibbs.
4) In a subsequent talk with Smith, Ellis told him about the problem of the
retaining pond and detailed the reasons for avoiding drainage to the east
of the houses.
5) In early October 2005 , Wayne Rife , representing Robinson, called Ellis
to arrange a survey of both properties by MDG. Ellis agreed to allow this
on the condition that she and her representatives , Gordon Evans
(environmental consultant and former resident at the ranch) and Randall
Pratt (ranch manager), must be present. The survey took place on
October 22 , 2005 . Robinson and Smith were also present. All were told
by Ellis that the survey and any new and final plat, including a plat
showing corrections and an engineer 's plan for drainage , would need to
be sent to Mr. Liesman for his approval before the Partnership would
agree to them. Ellis indicated the preferred natural drainage route to
Robinson and offered to conduct his survey team to see it. This offer was
declined .
6) No further communication was received until February 1, 2006 , when
Mark McAuliff contacted Chuck Ellison, attorney for the Partnership for
the City sewage easement, concerning an offer to purchase a drainage
easement from the Partnership along the exact path proposed by
Robinson and MDG. Both Robinson and the City have been told that the
proper and natural and traditional drainage route is through the ditch to
the west of the houses and that their proposed route would destroy the
land and the property value. Therefore the offer was declined.
7) Through Chuck Ellison, other communications have been exchanged, in
which Ellis expressed her concerns and her willingness to meet with
Robinson, Adams, and Rife. No actual meeting was proposed to her.
8) Ellison received the Drainage Outfall for Williamsgate Subdivision and
mailed it to Ellis. It was delivered to Liesman. He has written his
opinion and it was brought to the May 24 , 2006, meeting. It contained
several reservations about the design of the outfall for the proposed
terrain. More observations about the Plat and the retention pond were
included.
CONCLUSIONS:
In his comments on May 23, 2006, concerning the Drainage Outfall, Mr.
Liesman stated that IF the Developer has done his work right, the detention
is properly done, and the detained runoff is flowing along its traditional path,
there should be no problem with too much excess water and there would be
no need for an easement. Mark Smith has assured the Partnership that the
city would no longer ask for an easement.
Adams stated that he had not been on the Haupt property, that he had
assumed that the route for the Drainage Outfall would be preferable and did
not know that the natural, traditional path was to the west ditch. Ellis and
King suggested that he join them at the ranch following the meeting. Adams
and Rehm inspected the route and now agree that the natural and traditional
waterflow from Williamsgate is to the West Ditch. Adams is working on his
new plan for drainage and will consult with Evans and Pratt and send his
drainage outfall to Liesman for his approval. He has been cautioned by Ellis
that development of the natural path must not allow excess run-off that could
cause erosion in the sides of the ditch and/or result in excess water reaching
the stock tank on the Barger property.
CONTINUING CONCERNS:
1) Mr. Liesman has stated that the retaining pond for Williamsgate is
inadequate. We strongly suggest that Adams, Robinson, and the City
Engineers examine their calculations in light of the suggestions by Mr.
Liesman in his messages of September 30, 2005, and May 23 , 2006.
(Copies are included). It would be less costly to do the retaining pond
correctly now than to replace it when it proves to be inadequate and to
remedy any damage done to the Haupt or Barger properties.
.._ .
2) Since we have been told by Wendell Rehtn that the City has issued a
building permit and we also know that the storm drainage plan is still in the
developing stages, we strongly suggest that construction on the houses not
begin until a drainage plan is accepted by the Partnership. Both the drainage
system (including the retaining pond) and control of the currently altered
storm water and silt flow need to be addressed immediately.
3) The Partnership has been disturbed by the lack of response to our requests
for specific information and disappointed that no attention was given to our
statements concerning the land itself. We are encouraged by the opening of
dialogue at the meeting and are hoping that all problems can be solved with
an open exchange of information.
Donald Ellis
From:
To:
Sent:
Subject:
"Bob Liesman" <Bliesman@mbcengineers.com>
<dona Id . e. ell is@worldnet. att. net>
Monday , October 03 , 2005 7:41 AM
FW: Williamsgate Subdivision
Bob Liesman, P.E.
Vice-President
Macina, Bose, Copeland & Associates, Inc.
1035 Central Parkway North
San Antonio, Texas 78232
(210) 545-1122, Fax: (210) 545-9302
www.mbcengineers.com
bobliesman@mbcengineers.com
From: Bob Liesman
Sent: Friday, September 30, 2005 11:54 AM
To: 'agibbs@cstx.gov'
Subject: Williamsgate Subdivision
Mr. Alan Gibbs and Mrs Rene Ellis :
Page 1 of2
At Mrs. Ellis ' request and with Mr. Gibbs cooperation I have (finally) taken time to review MDG 's plans for that
single family subdivision proposed for that 20.27-acre tract abutting the southeast property line of the Haupt farm
on Old Welbourne Road . As we all know by now, Mrs . Ellis and her siblings (who now own the farm) are very
concerned about the possible harmful effect on their property of increased runoff from the proposed subdivision .
For the past 25 years or so I have been doing land development engineering here in San Antonio , and therefore
looking at questions such as here considered from a Developer perspective. I certainly do not claim to be any
great expert, but I am going to declare my opinions for whatever they are worth . I have told Mrs. Ellis that an
upgradient property owner cannot divert runoff, nor increase runoff, nor concentrate runoff on his neighbor without
putting himself in jeopardy for lawsuit; also that it is my understanding that The City of College Station requires
stormwater detention for developments such as that proposed. Saying that, it is also my understanding that the
outcome of a lawsuit is a function not only of factual issues, but degree of damage. From maps that I have seen,
the natural course of runoff from most all of the Williamsgate property appears to be onto and thru the Haupt
property. Therefore, no appreciable diversion of watershed is proposed -or would be allowed by the City. Any
development of property will increase the amount (that is volume) of water that flows off the tract. Detention , as
proposed for this project , retards the increase in RA TE of runoff by holding some of that volume for delayed , later
release . For a small watershed such as this, that lengthening of the time of discharge is negligible. So , it appears
to me that the strategy for handling runoff from the proposed subdivision is appropriate , but I do have some
issues with the details.
Mrs. Ellis and family are concerned about the quality of runoff as well , but I cannot speak to that issue . Certainly
that runoff will contain some unnatrural products like any development would.
Let me move-on to some those details .
1. I would agree with the computation of runoff rate prior to development for the development as a whole .
However, I think that the calculation of post-development runoff is low, due to an underestimation of post-
development impervious cover. The report uses a runoff coefficient of 0.54, based upon an assumption of
impervious cover of 13.8%. Considering roof tops, driveways, and street paving , I think that the impervious
cover will be more like 40% for this small lot subdivision . Here in San Antonio, a development like this would
warrant a runoff coefficient of 0.67 . [I am presuming a 20' front setback, a 40 ' rear setback, and 10' side
setbacks .]
5130106
Page 2 of2
' ,.
2. MDG is comparing gross pre-devel. runoff to gross post-devel. runoff. While that may be good for a point a
couple of hundred feet downstream from the Haupt property line (but with a "C" value adjustment), at that
property comer where they wish to discharge, the natural drainage area appears to me to be only about half
of that 20.27 acres. So, to not increase Q at that point, one would need a considerably larger detention
volume , so ~s to counter both the increase in impervious cover and the increase in drainage area at that
point. Once the post-devl.. "Q" might be corrected (if you concur Mr. Gibbs), this second discrepancy
might be neglected IF the Developer could convince Mrs. Ell is, et al , that he could (to their satisfaction)
improve the channel in the Haupt property between the property line and that point downstream where the
full area of the subdivision naturally came to focus -so as to not increase flood effect thru that reach .
3. MDG appears to have the discharge for the basin at an elevation about a foot below existing ground , and
they appear to be proposing a "grade-to-drain " channel for some 250 ft. or so . I have suggested to Mrs .Ellis
that I do not think that is a bad thing . That which helps runoff traverse their property more quickly makes it
less boggy . The question would be to what extent might such a channel hinder their farming operation as
regards driving thru it or around it. -I don 't know ..
Bob Liesman, P.E.
Vice-President
Macina, Bose, Copeland & Associates, Inc.
1035 Central Parkway North
San Antonio, Texas 78232
(210) 545-1122, Fax: (210) 545-9302
www.mbcengineers.com
bobliesman@mbcengineers.com
5130106
..
Donald Ellis
From:
To:
Sent:
Subject:
"Bob Liesman" <Bliesman@mbcengineers.com>
<donald .e.ellis@worldnet.att.net>
Tuesday, May 23, 2006 10 : 13 AM
Haupt Property in College Station
Page 1 of2
I have looked-over the plan sheet by MDG Engineers for the proposed drainage outfall channel from the
Williamsgate Subdivision . Allow me to offer the following comments .
1. From other, earlier information transmitted to Mrs . Ellis by the Developer (and assuming that that
topographic data was true and correct), it appears to me that the natural course of runoff from the area of
(most of) the proposed Williamsgate subdivision was, indeed, toward and along the natural low which the
proposed channel follows. Apparently, quite some time ago , the Haupt family created a drainage ditch
southwest of this low for the purpose of redirecting some of the upgradient runoff entering their property
away from their lower fields . Whether this was a good idea , or legal , or whether it establishes the "existing"
runoff pattern that the Williamsgate subdivision should follow , I'll leave to others .
2. Since my earlier critique of the hydrology for the Williamsgate detention I have not seen any revised plans .
I then wanted to simply point-out a couple of things for the City's engineer to re-review . While each City
has a different procedure for sizing these basins , it appeared to me at the time that that initial design
perhaps did not make an accurate calculation of existing runoff at the point of discharge since it seemed
that they were diverting some drainage area to their basin (and consequently that low point) which did not
naturally flow to that point. That is , while the basin may detain runoff from the whole subdivision to a
natural runoff rate , I thought that they might be increasing the flow rate at that point. If the City has re-
reviewed the calculations and is satisfied , I am not going to question it any further.
3. So , let's assume that the runoff from Williamsgate is going to be directed toward/ down that natural low. A
problem that I see is that all along that designed channel, the Engineer proposes to create a "bermed-up"
channel whose sides are generally about 1 vertical foot higher than the existing ground. [Everywhere the
sides are at least six(6) inches higher than existing ground.] While this would let the upgradient runoff
"pass-by" the Haupt home and confine its effect , it would at the same time preclude rainfall at and around
the Haupt home from being able to runoff adequately, thus creating a swampy area east and southeast of
the house . Note that the existing topo shown on that channel plan indicates a very mild grade from the
house( es) down to that low . If you create a foot-high berm between the low and those houses and yards,
that area west of the channel isn't going to drain.
(A) I have told Mrs . Ellis that I felt that IF the detention was properly done and if she was
uncomfortable with the possible implications of granting such an outfall easement, she should not
have to and that The City should not demand that the Williamsgate developer obtain such an
easement -as long as he is properly detaining. Just let the water run off as it does today.
(B) On the other hand, I think that improving that drainage way is probably a good idea -for current
use of the Haupt property and for future use . But the channel needs to be lower. Specifically, its
sides need to be not higher than the ground for a reasonable distance left and right of the low . I
think that such would mean constructing a new culvert under the Haupt's driveway , but I can 't tell
for sure . [My recollection is that the driveway already is at least 1.5 vertical feet above the low .]
The two 12 " pipes are clearly inadequate to preclude backwater effect, but if the flow rate is not
being increased, that backwater effect should not be any worse that it is today , and it will be
short-term since the drainage area is relatively small .
Bob Liesman, P .E.
Vice-President
Macina, Bose, Copeland & Associates, Inc.
1035 Central Parkway North
San Antonio, Texas 78232
5130106
(210) 545-1122, Fax: (210) 545-9302
www.mbcen ineers.com
bobliesman@mbcen · eers.com
No virus found in this incoming message .
Checked by AVG Free Edition .
Version : 7.1 .392 /Virus Database : 268.7 .0/345 -Release Date : 5/22/06
Page 2 of2
5130106
v
' •
I ) ~ ' . -
. l
I
.
DRAINAGE REPORT
FOR
W I LLIAMSGATE SUBDIVISION
20.27 ACRE TRACT
(VOLUME 4628 , PAGE 221)
CRAWFORD BURNETT LEAGUE , A-7
MDG JOB NO. 000886-3736
COLLEGE STATION, BRAZOS COUNTY, TEXAS
JUNE 2005
fkiJ
.:------
~c., _2_5_5_1 _T_ex_a_s _A_ve_. _s_ou_tl_1,_S_te_. A_, C_o_ll_eg_e_S_ta_ti_on_,_T_X_7_7_84_0 _____ _
~~~4' Ofc: 979.693 .5359 Fax: 979.693.4243 Em ail: mdgcstx@yahoo.com ~~o~~~ ~~o
<:j'<:> (j
r
Certification Sheet
"I hereby certify that this report (plan) for the drainage design of Williamsgate
Subdivision was prepared by me (or under my supervision) in accordance with the
provisions of the City of College Station Drainage Policy and Design Standards for the
owner's thereof."
Registered Professional Engineer
State of Texas No.
)
Project Scope:
This report outlines the drainage improvements for Phases I, II, and III of Williamsgate Subdivision.
This drainage report will consist of the requirements necessary for the improvements of this 20.27-
acre site in accordance with the provisions of the Drainage Policy and Design Standards of the City
of College Station .
General Location and Description:
The project site is located on the west side of Wellborn Road along Rock Prairie Road in the Carter
Creek Drainage Basin. Currently, the project site is undeveloped and exists in a relatively natural
state that is covered with native grasses, weeds, and light underbrush. This land generally slopes
radially outward from a highpoint located in the southern corner of the site with a grade of
approximately 2.74 %. Because of the high point, the majority of the site drains to the northern
corner of the tract.
Drainage System Modeling:
For all drainage system modeling, the volume of runoff will be calculated. The drainage calculations
are summarized accordingly using the Rational Method: Q = CIA, where "Q" is the runoff in cubic
feet/second, "C" is the runoff coefficient, "I" is the storm intensity in inches/hour for each selected
frequency, and "A" is the drainage area in acres. The time of concentration was calculated using the
equation: T = D/60V. A minimum 10-minute time of concentration for all calculations will be
assumed. The selected frequencies will be 2, 5, 10, 25, 50, and 100-year rainfall events. The project
site is former cow pasture with hard clay soils that increase the runoff. This was accounted for when
choosing "C " from the table iri the design manual. Tabulations of pre-development and post-
devel o pment runoffs for the site are provided.
Storm Sewer Inlets
Storm sewer inlets are a part of the storm sewer system evaluation. They were sized
according to the determined I 0-year land area runoffs using the equation: Q = 3Ly312 , where
"Q" is the capacity in cubic feet/second, "L" is the length of the opening which water enters
into the inlet, and "y" is the total depth of water or head on the inlet. A table showing the
sizes , as wel I as ground elevations for the inlets is provided .
Storm Sewer System
Due to the low grade of the site, elliptical concrete pipes will be used for the storm sewer
system to allow a 2 ft cover. Pipes with an area of 19 x 30 inches or less were sized assuming
a 25% reduced cross-sectional area.
The program StormCad by Haestad Methods aided storm sewer system calculations. Within
this program , basic geometry and characteristics of a storm sewer system can be defined.
This would include data s uch as drainage basin calculations, type and configuration of
several types of inlet boxes, and controlling factors of the conveyance system. From this
program critical information can be determined about the storm sewer system. Tables
providing information on the storm sewer for both the 10 and I 00-year rainfall events are
provided, as well as 10 and 100-year HGL profiles .
)
. -'
According to the Third Edition of the State Department of Highways and Public
Transportation Bridge Division Hydraulic Manual, "if the plotted hydraulic grade line does
not rise above the top of any manhole or above the gutter invert of any inlet, the pipe system
is considered satisfactory. Wherever it does rise above any of these points , however, blow-
outs through inlet slots and manhole covers will probably occur during a design storm." For
the Hancock Loop South storm sewer line, the HGL rises above some of the junctions and
inlets during the I 00-year storm event. This is because some of the pipe runs were placed on
a slope that is less than the energy slope of the pipe in order to accommodate the grading of
the site. However, the storm sewer system is considered "satisfactory" because the HGL doe s
not rise above the inlets or junctions for the I 0-year design storm period.
Drainage Improvements:
As previously discussed, the majority of the storm water runoff flows to the northern corner of the
site. Because of this , a detention basin will be located in the northern corner of the tract. Due to
existing low s pots in the western and northern corners of the site, along with a 2-foot minimum for
ground cover, sto rm sewer pipes. were arriving at the detention ba s in be low its ba se e levation . In
order to accommodate the sto rm sewer, the maj or ity of the s ite was re-graded to a uniform s lope of
2.10 %. Outflow from the detention ba s in will be regulated by a rect ang ular weir and transported off
site dir ect ly int o an existing draina ge path .
Detention Basin:
Detenti on requirements are determined by graphical mean s. Tabul at ions of pre-development and
post-d eve lopment hydrographs of the site are provided . The hydro grap hs are base d on the standard
SCS unit hydro grap h with time to peak discharge set to equal the time of concentration a nd the total
base time set at 3.00 tim es the time of concentration. The following calculation was used to
determin e the required volume for each draina ge area :
Volume Required= Vol 11 ost -Vo1 11 rc
Where
Vol po st = Y:z(Q po st)(3Tc)(6 0)
Vol pre = Y:z(Qpr e)(3Tc)(60)
The initial estimate of the required volume for the detenti on basin was calculated to be l 0911 cf.
When the storage retained was calculated for eac h sto rm eve nt it was found that 21,040 cf was
required . Makin g this adjustment and accounting for I foot of fre e boa rd, the detention basin was
designed as 32749 cf.
Routing Methods
The following routing calculations were performed after sizi ng the recta ngu lar weir to
regulate the detention ba s in o utfl ow to be le ss than the pre-development runoff flows. The
rectan gular we ir was s ized us in g the following equation:
Q=3Ly312
)
Where
Q =di sc harge in cfs
L =le n gth of the opening which water e nters into the weir
y =tota l d e pth of water or head on th e we ir
T hi s eq uat io n dete rmin e d th e maximum le n gth for t h e weir that wo uld regul ate the o utfl ows
from th e detention basin to that of th e pre-development fl ows. Knowing th e dimensions of
t h e recta ng ular w e ir , a routing analysis of the d etenti o n bas in co ul~ be perform ed.
T he infl ow to the detention bas in was d e termined as the t ota l po st-devel o pment flow from the
si te . The o utfl ow from the weir of th e detention basin was d ete rmined using the Puls routing
method.
H 1 was determined from the. function of the pl ot of Depth vs . Storage.
2S 1 I 6.t -0 was dete rmin ed from the storage indi cati o n functi o n from the plot of 2S I 6.t-0 vs.
Depth .
2S 2 /6.t +O was calcu lated us in g the fo ll ow in g e qu at io n:
H was determined from th e storage indi cation fun ctio n from the plot of Depth vs. 2S /6.t +O.
T he tota l o utfl ow from the o utl e t st ru cture wa s determined fro m the re s ultin g function of the
p lot of O utflow vs. Depth .
Gra ph s a nd ta bl es representing thi s routing process are pro vided. /,,,,...; ~ . »\' I"' f Results:
The pre-development run off for the s it e was determi Cl to be 62.34, 75.8 ~7 .24, 109.93, and
114 .77 cfs for the 2, 5, I 0 , 25, 50, a nd I 00-y rainfall eve nt s , respe ~fter performin g a
ro utin g a nal ysis of the detent io n basin w ith a n 8.0 foot rectangular wei r, it was determined that the
a bo ve menti o ned drainage improve ments will satisfy the needs of the s ite in accordance w ith the
provisions of the City of Co ll ege Station Drainage Policy and Design Standards. The maximum
ted outflows from the we ir fo r the previously menti o ned rainfall events are 59.80, 73 .87 ,
96.3 1, I 09.65, a nd 114.75 cfs. T he se flows a re below th e pre-development flows as re quired
Drainage Policy and Design Stand ards .
)
SITE RUNOFF CALCULATIONS
)
Pre-Development
GENERAL INFORMATION
Description : Pre-Development Drainage Area
Drainage Area = 20 .27 acres
GIVEN
Velocity of Runoff= 1.67 1
1sec
Coefficient of Runoff= 0.49
Travel Distance = 1020 ft
Time of Concentration = 10 .18 min
**NOTE : Min imum T c allowed = 10 min . RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .806
Coefficient (b) = 65
Coefficient ( d) = 8
5 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0 .785
76
8.5
10YEARFREQUENCYCONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0.763
80
8.5
25 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0.754
89
8.5
50 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0.745
98
8.5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0.73
96
8
Rainfall Intensity (1 2) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10 ) =
Rainfa ll Intensity (1 25 ) =
Rainfa ll Intens ity (1 5 0 ) =
Rainfall Intensity (1 100 ) =
Williamsgate Subdivision
Job# 000886-3736
Project Manager: Lee Adams
Calculations : L. Brooks
62.336 cfs
75.830 cfs
85.131 cfs
97.236 cfs
109.928 cfs
114.769 cfs
6/2 7/2005
)
Post-Development
GENERAL INFORMATION
Descrip tion : Pos t-Development Dra inage A rea
Lan d Area = 17.8 1 acres
Im perviou s A rea =
Tota l Draina ge Area =
GIVEN
2.46 acres
20 .27 ac res
Lan d Vel ocity of Runoff= 1.67 I sec
Land Coefficient of Run off= 0.49
Land T ravel Distance = 155 ft
Land Ti me of Concentration = 1.55 min
Impervious Velocity of Runoff= 5 .67 nl sec
Impe rviou s Coefficie nt of Runoff= 0 .9 0
Imp erviou s Trave l Distan ce = 1316 ft
Impe rvi o us Ti me of Co ncen trat io n = 3.87 min
Comp osite Coe ffi cie nt of Runoff = 0.54
To tal Tim e of Co ncen tratio n = 5.42 min
**NOTE: Minimum Tc allowed= 10 mi n . RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficie nt (e) =
Coefficient (b) =
Coefficient (d) =
0.806
65
8
5 YEAR FREQUENCY CONSTANTS
Coe ffi cient (e) = 0 .785
Coe ffic ient (b) = 76
Coeffic ient (d) = 8 .5
10YEARFREQUENCYCONSTANTS
Coe ffi cient (e) = 0.763
Coeffic ient (b) =
Coeffic ient (d) =
80
8 .5
25 YEAR FREQUENCY CONSTANTS
Coeffic ie nt (e) =
Coe ffi c ie nt (b) =
Coeffic ie nt (d) =
0 .754
89
8 .5
50 YEAR FREQUENC Y CONSTANTS
Coe ffic ient ( e) =
Coeffic ient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0.73
Coe ffi cient (b) = 96
Coeffic ient (d) = 8
Rainfall In tensity (1 2) =
Rainfa ll Intensity (1 5) =
Rainfall Intens ity (1 10) =
Rainfa ll Intensity (1 25) =
Rainfa ll Intensity (1 50) =
Rainfa ll Intensity (1 100) =
W illi amsgate Sub di vision
Jo b # 000886-3736
Pr oject Manage r: Lee Adams
Ca lculations: L. Brooks
6 .327 in/hr
69.908 cfs
7 .693 '"/hr
85 .006 cfs
8 .635 '"/hr
95.412 cfs
9 .861 "'/hr
108 .970 cfs
123.182 cfs
11 .639 in/hr
128.613 cfs
6/27/2 005
)
,,
T, (min) Post-Deve l opment, Pre-D evel opment (cfs)
2 Year 5 Year 10 Year
0 0 0 0 0 0 0 0
10 10.2 69.908 62 .336 85.006 75.830 95.412 85.13 1
20 20 .3 34 .95 4 31 .168 42.503 37 .915 47 .706 42 .565
30 30 .5 0 0 0 0 0 0
VOL= 5974 VO L = 7235 VOL= 8104
25 Year 50 Year 100 Year
0 0 0 0 0 0 0 0
10 10.2 108 .970 97 .236 123.182 109 .928 128 .6 13 114 .769
20 20.3 54 .485
30 30.5 0
VOL=
2-Year Hydrograph
t~~m l l
a r T'' : 0 -' .
0 10 20
Time (min)
30 40
10-Year Hydrograph
0 10 20
Time (min)
30 40
50-Year Hydrograp h
I :~W1?f~,,[·············1
o I " .
0 10 20
Time (min)
Wi ll iamsgate Subd ivision
Job# 000886 -3736
30 40
48 .618 6 1.59 1 54.964 64 .307 57 .384
0 0 0 0 0
9248 VOL= 10445 VOL= 10911
5-Year Hydrograph
--Post-Oevelopmen
·····"'·"P re-Developm ent
1 '~tif lm,]••mm i
--Post-Oevelopmen
·····Pre-Development
--Post-Oevelopmen
.-.· ... ·.·.·.·Pre-Development
0
0
0
Project Manager : Lee Adams
Ca lculations : L. Brooks
10
10
10
20
Time (min)
30 40
25-Year Hydrograph
20
T ime (min)
30 40
100-Year Hydrograph
20
Time (min)
30 40
--Post-Deve lopm e n
· ·.··.Pre-Development
--Post-Oevelopmen
· ······Pre-Development
--Post-Oevelopmen
········ Pre-Development
6/27/2005
DRAINAGE AREA RUNOFF CALCULATIONS
Post-Development
Area 1
GENERAL INFORMATION
Description : Post-Development Drainage Area 1
Land Area= 3 .64 acres
Impervious Area= 0 .11 acres
Total Drainage Area= 3.75 acres
GIVEN
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0.51
Total Time of Concentration= 10 .00 min
**NOTE: Minimum Tc allowed = 10 min. RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .806
65
8
5 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0.785
76
8.5
10 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .763
80
8.5
25 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.754
89
8 .5
50 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d ) =
0.73
96
8
Rainfall Intensity (1 2) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10 ) =
Rainfall Intensity (1 25) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations : Mark Taylor
12.235 cfs
7.693 "'/hr
14.878 cfs
8 .635 "'/hr
16.699 cfs
9.861 '"/hr
19.072 cfs
21.559 cfs
22.510 cfs
2/15/2005
)
Post-Development
Area 2
GENERAL INFORMATION
Description : Post-Development Drainage Area 2
Land Area = 2 . 19 acres
Impervious Area =
Total Drainage Area =
GIVEN
0.50 acres
2 .69 acres
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .57
Total T ime of Concentration= 10 .00 m in
**NOTE: Minimum T c allowed = 10 min . RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0 .806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .785
76
8 .5
10 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .763
80
8 .5
25 YEAR FREQUENCY CONS:f ANTS
Coefficient (e) = 0 .754
Coefficient (b) = 89
Coefficient (d ) = 8 .5
50 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coeffic ie nt (d) =
0 .73
96
8
Rainfall Intens ity (1 2 ) =
Rainfall Intensity (1 5) =
Ra infall Intensity (110) =
Ra infall Intensity (1 25) =
Ra infall Intens ity (1 50 ) =
Rainfall Intens ity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
9.856 cfs
7 .6 93 '"/hr
11.984 cfs
8 .635 '"/hr
13.451 cfs
9.861 "'/h r
15.363 cfs
11 .1 48 '"!h r
17.367 cfs
18 .132 cfs
2/15/2005
Post-Development
Area 3
GENERAL INFORMATION
Description : Post-Development Drainage Area 3
Land Area= 2 .04 acres
Impervious Area =
Total Drainage Area=
GIVEN
0 .18 acres
2 .22 acres
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .53
Total Time of Concentration= 10.00 min
**NOTE : Minimum Tc allowed= 10 min . RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .785
Coefficient (b) = 76
Coefficient (d) = 8 .5
10 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .7 63
80
8 .5
25 YEAR FREQUENCY CONST ANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0.754
89
8 .5
50 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.73
96
8
Rainfall Intensity {1 2) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25) =
Rainfall Intensity (1 50) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations : Mark Taylor
6 .327 '"/hr
7.552 cfs
7 .693 "'/hr
9.183 cfs
8.635 "'/hr
10.308 cfs
9.861 "'/hr
11.772 cfs
11 .148 1%r
13.308 cfs
11 .639 '"!hr
13.894 cfs
2/15/2005
}
Post-Development
Area4
GENERAL INFORMATION
Description : Post-Development Drainage Area 4
Land Area = 1.65 acres
Impervious Area =
Total Drainage Area=
GIVEN
0.29 acres
1.93 acres
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0.56
Total Time of Concentration= 10 .00 min
**NOTE : Minimum Tc allowed = 10 min. RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0.806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .785
Coefficient (b) = 76
Coefficient (d) = 8.5
10 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0 .7 63
80
8 .5
25 YEAR FREQUENCY CONST ANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .754
89
8 .5
50 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0.745
98
8 .5
100 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .73
96
8
Rainfall Intensity (1 2) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25) =
Rainfall Intensity (1 50) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations : Mark Taylor
6 .327 '°/hr
6.890 cfs
7 .693 "'/hr
8.377 cfs
8 .635 '"/hr
9.403 cfs
9 .861 "'/hr
10.739 cfs
11 .148 1%r
12.140 cfs
11 .639 1%r
12.675 cfs
2/15/2005
' )
Post-Development
Area 5
GENERAL INFORMATION
Description : Post-Development Drainage Area 5
Land Area= 0 .62 acres
Impervious Area = 0 .17 acres
Total Drainage Area= 0.78 acres
GIVEN
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0.90
Composite Coefficient of Runoff= 0.58
Total Time of Concentration= 10.00 min
**NOTE: Minimum Tc allowed = 10 min. RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.806
65
8
5 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.785
76
8.5
10 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.763
80
8.5
25 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .754
89
8 .5
50 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0.745
Coefficient (b) = 98
Coefficient (d) = 8.5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.73
96
8
Rainfall Intensity (1 2 ) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25 ) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job# 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
6 .327 '"/hr
2.921 cfs
7.693 "'/hr
3.552 cfs
8.635 "'/hr
3.987 cfs
9.861 '"/hr
4.553 cfs
11 .148 "\r
5.147 cfs
5.374 cfs
2/15/2005
( )
Post-Development
Area 6
GENERAL INFORMATION
Description: Post-Development Drainage Area 6
Land Area = 1. 13 acres
Impervious Area=
Total Drainage Area=
GIVEN
0 .19 acres
1.31 acres
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .56
Total Time of Concentration= 10 .00 min
**NOTE: Minimum Tc allowed = 10 min. RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0 .806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0 .785
Coefficient (b) = 76
Coefficient (d) = 8 .5
10 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .763
80
8 .5
25 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .754
89
8.5
50 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .73
96
8
Rainfall Intensity (1 2 ) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25) =
Rainfall Intensity (1 50) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
6 .327 '"/hr
4.650 cfs
7.693 "'/hr
5.655 cfs
8 .635 "'/hr
6.347 cfs
9 .861 '"/hr
7.249 cfs
11 .148 '"!hr
8.194 cfs
11 .639 '"/hr
8.556 cfs
2/15/2005
t )
Post-Development
Area 7
GENERAL INFORMATION
Description : Post-Development Drainage Area 7
Land Area = 3.30 acres
Impervious Area= 0.23 acres
Total Drainage Area= 3 .53 acres
GIVEN
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .53
Total Time of Concentration= 10.00 min
**NOTE: Minimum Tc allowed = 10 min . RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0.806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .785
Coefficient (b) = 76
Coefficient (d) = 8 .5
10 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .763
80
8 .5
25 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0.754
89
8.5
50 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .73
96
8
Rainfall Intensity (1 2 ) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25 ) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity {1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations : Mark Taylor
6 .327 '"!hr
11.845 cfs
7 .693 '"/hr
14.403 cfs
8.635 "'/hr
16.166 cfs
9 .861 "'/hr
18.463 cfs
20.871 cfs
21.792 cfs
2/15/2005
J
Post-Development
Area 8
GENERAL INFORMATION
Description : Post-Development Drainage Area 8
Land Area= 2 .75 acres
Impervious Area = 0 .28 acres
Total Drainage Area = 3.03 acres
GIVEN
Land Coefficient of Runoff= 0.50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .54
Total Time of Concentration= 10 .00 min
**NOTE: Minimum Tc allowed = 10 min . RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficient (e) = 0 .806
Coefficient (b) = 65
Coefficient (d) = 8
5 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .785
76
8 .5
10 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0 .763
Coefficient (b) = 80
Coefficient (d) = 8 .5
25 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0 .754
89
8 .5
50 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .73
96
8
Rainfall Intensity (1 2 ) =
Rainfall Intensity (1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25 ) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
10.350 cfs
7.693 '"/hr
12.586 cfs
8.635 "'/hr
14.126 cfs
9 .861 "'/hr
16.134 cfs
18.238 cfs
11 .639 '"!hr
19.042 cfs
2/15/2005
{ )
Post-Development
Area 9
GENERAL INFORMATION
Description: Post-Development Drainage Area 9
Land Area= 1.09 acres
Impervious Area=
Total Drainage Area =
GIVEN
0 .26 acres
1.35 acres
Land Coefficient of Runoff= 0 .50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0 .58
Total Time of Concentration= 10 .00 min
**NOTE: Minimum Tc allowed= 10 min . RESULT
2 YEAR FREQUENCY CONST ANTS
Coefficient (e) =
Coefficient (b) =
Coefficient ( d) =
0 .806
65
8
5 YEAR FREQUENCY CONST ANTS
Coefficient . ( e) =
Coefficient (b) =
Coefficient (d) =
0 .785
76
8 .5
10 YEAR FREQUENCY CONSTANTS
Coefficient (e) =
Coefficient (b) =
Coefficient (d) =
0 .763
80
8 .5
25 YEAR FREQUENCY CONST ANTS
Coefficient (e) = 0 .754
Coefficient (b) = 89
Coefficient (d) = 8 .5
50 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8 .5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .73
96
8
Rainfall Intensity {1 2 ) =
Rainfall Intensity {1 5) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
4.977 cfs
7 .693 "'/hr
6.052 cfs
8.635 '"/hr
6.793 cfs
9 .861 "'/hr
7.758 cfs
8.770 cfs
9.157 cfs
2/15/2005
i )
Post-Development
Area 10
GENERAL INFORMATION
Description : Post-Development Drainage Area 10
Land Area = 3.19 acres
Impervious Area = 0 .26 acres
Total Drainage Area= 3.45 acres
GIVEN
Land Coefficient of Runoff= 0.50
Impervious Coefficient of Runoff= 0 .90
Composite Coefficient of Runoff= 0.53
Total Time of Concentration= 10.00 min
**NOTE : Minimum Tc allowed = 10 min. RESULT
2 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.806
65
8
5 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.785
76
8.5
10 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient ( d) =
0.763
80
8.5
25 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.754
89
8 .5
50 YEAR FREQUENCY CONST ANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0 .745
98
8.5
100 YEAR FREQUENCY CONSTANTS
Coefficient ( e) =
Coefficient (b) =
Coefficient (d) =
0.73
96
8
Rainfall Intensity (1 2) =
Rainfall Intensity (1 5 ) =
Rainfall Intensity (1 10) =
Rainfall Intensity (1 25 ) =
Rainfall Intensity (1 50 ) =
Rainfall Intensity (1 100) =
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
11.664 cfs
7 .693 '"/hr
14.183 cfs
8.635 '"/hr
15.919 cfs
9.861 '"/h r
18.181 cfs
20.552 cfs
21.458 cfs
2/15/2005
·, )
INLET & STORM SEWER ANALYSIS
)
Inlet#
14
13
12
18
16
110
19
17
Williamsgate Subdivision
Job # 000886-3736
Length
(ft)
13.0
10 .0
13.0
14 .0
6 .0
15 .0
7 .0
15.0
Inlet Sizing
10-Year Storm Everit
Total Area Total Flowrate
(acres) (cfs)
2.71 13.390
2.22 10.308
2 .69 13.451
3.03 14 .126
1.31 6.347
3.45 15.919
1.35 6 .793
3.53 16 .166
Project Engineer: Lee Adams
Calculations: Mark Taylor
Inlet Lip Elevation
(ft)
311 .30
309 .75
307 .00
313.70
313.45
316 .65
314 .95
313 .10
2/15/2005
Pipe 1zing
10-Yr Storm Event
Section Flowrate Velocity Length Slope Size Capacity Upstream Invert
(cfs) (ft/s) (ft) (ft/ft) (in) (cfs) (ft)
14-13 13.48 4 .88 193 0 .00803 19 x 30 22 .53 307 .70
13-12 23 .14 8.67 70 0 .01571 19 x 30 31 .51 306 .05
18-16 14 .16 4 .30 30 0 .00833 19 x 30 22.95 310 .10
16-J2 20 .47 6 .27 78 0 .01410 19 x 30 29 .85 309 .75
11 O-J4 15.92 4 .82 40 0.01000 19 x 30 25 .14 313 .05
J4-19 15.83 4 .80 130 0 .00923 19 x 30 24 .15 312 .55
19-J3 22.16 6.72 70 0 .01771 19 x 30 33 .45 311 .25
J3-1 7 22 .01 5 .52 170 0 .00482 22x34 22 .19 309 .82
17-J2 36 .93 9 .26 110 0 .01409 22 x 34 37.93 308.90
J2-J1 56 .05 9 .14 170 0 .00982 27 x 42 56 .18 306 .9 1
J1 -12 55 .39 9.04 67 0 .00955 27 x 42 55.40 305 .14
12-0ut2 89 .67 12.30 17 0.01500 29 x45 90 .24 304 .33
**Note : Pipes of 19 x 30 in ches or less in size are sized assuming 25 % reduced cross-sectional area.
Williamsgate Subdivision
Job # 000886-3736
Project Engineer: Lee Adams
Calculations: Mark Taylor
'--
Downstream Invert Upstream HGL Downstream HGL
(ft) (ft) (ft)
306 .15 308 .77 307 .89
304 .95 307 .0 6 307 .00
309 .85 311 .67 311 .57
308 .65 311 .26 310 .59
312 .65 315.36 315.20
311 .35 315.02 314 .50
310 .01 314 .15 313 .61
309 .00 313.53 312 .72
307 .35 312 .06 310 .59
305 .24 309.94 308 .27
304 .50 307.64 307 .00
304 .07 306.62 306 .37
2/15/2005
HANCOCK LOOP NORTH 10-YEAR HGL
-· -··-·--. ------·---------...... --·
In(et: I3 ---------·-··----
In(et: I4
RiMI 311.30 ft
SuMp : 307.60 f't
---·-·---·-----------Rl1"l :-Jo9 _7-s --f'-t.;-~-~-·=.=::-::::-:-:--=:-:--::-:~~----:-=-~.·~:--·-==~~-----suMp 1 305, 95 ~t
Outlet, Outlet ~~!~o~f ;t:~:_-_ ------\ . ------~:~:-= ..
RIM < 304 .07 ft -""' ·---{-"-
SUMp • 304.01 ft ~i°eln~~;~~tjs 4.~ -_:--__ ~ _·_ _ • -\ijoe,
14
-
13
-----·-------..
Dn Invert· 304 iJf f A Up Inver t i 307, 70 f't
Length: 17.00 f'°t UPiper' I3-It~ 306 5
Dn Invert: 306 .15 f't Section Size, 29x45 Inch nR 1 g~g~t ; 304:2
5
rf Length' 193.00 ft
Y:\)736·WiUiamsilate\Dra inage \37J6-0ILN_ 1ovR_HG L.dwg, Ol /1 512005 10:53 :57 N-1, llBEN\hp l>hocnsmort 11 15 series, 1:44.1579
Length: 70.00 f't Section Size: 19x30 inch Section Size : 19x30 Inch
-
-----
HANCOCK LOOP
SOUTH 10-YEAR HGL
--·----
;o-, ... :.
Y:\3736-W/llia
I :93.4609 msgate\Drainage13736-0ll5
_loYR_HGL.dl'lll, 02/1512005
10:58:15 AM, \IBEN\h
P Pho!osmart l2!S
-----senes,
\ .)
Inlet#
14
13
12
18
16
110
19
17
Williamsgate Subdivision
Job # 000886-3736
Length
(ft)
13.0
10.0
13.0
14.0
6 .0
15 .0
7 .0
15.0
Inlet Sizing
100-Year Storm Event
Total Area Total Flowrate
(acres) (cfs)
2 .71 18.170
2 .22 13 .894
2 .69 18.148
3.03 19.042
1.31 8.556
3.45 21.458
1.35 9.157
3.53 21.792
Project Engineer: Lee Adams
Calculations: Mark Taylor
Inlet Lip Elevation
(ft)
311.30
309.75
307 .00
313.70
313.45
316.65
314.95
313.10
2/15/2005
Section Flowrate Velocity
(cfs)
14-13 18.17
13-12 31 .30
18-16 19.09
16-J2 27.63
110-J4 21.46
J4-19 21 .37
19-J3 30 .07
J3-17 29 .92
17-J2 50.47
J2-J1 76 .75
J1-12 76 .09
12-0ut2 123.32
Williamsgate Subdivis ion
Job# 000886-3736
(ft/s )
5 .51
9.49
5.78
8 .37
6 .50
6.48
9 .11
7 .50
12.65
12.52
12.41
16.68
Length Slope Size
(ft) (ft/ft) (in)
193 0 .00803 19 x 30
70 0 .01571 19 x 30
30 0 .00833 19 x 30
78 0.01410 19 x 30
40 0 .01000 19 x 30
130 0 .00923 19 x 30
70 0 .01771 19 x 30
170 0.00482 22x34
110 0.01409 22 x34
170 0 .00982 27 x 42
67 0 .00955 27 x42
17 0 .01500 29 x45
Pipe Sizing
100-Yr Storm Event
Capacity Upstream Invert
(cfs ) (ft)
22 .53 307 .70
31 .51 306.05
22.95 310.10
29 .85 309.75
25 .14 313 .0 5
24 .15 312.55
33.45 311 .25
22 .19 309.82
37 .93 308 .90
56 .18 306 .91
55 .40 305 .14
90 .24 304.33
Project Engineer: Lee Adams
Calcu lat ions : Mark Taylor
Downstream Invert
(ft)
306 .15
304 .95
309 .85
308.65
312 .65
311 .35
310 .01
309 .00
307 .35
305 .24
304 .50
304 .07
. .._,
Upstream HGL Downstream HGL
(ft) (ft)
309 .79 308.78
308.09 307 .00
313 .62 313.45
313 .19 312 .25
316 .51 316 .22
315.89 314 .95
314 .61 313 .61
314.59 313 .10
314.99 312 .25
312.52 309 .40
308.21 307.00
307 .01 306 .44
2/15/2005
HANCOCk LOOP NORTH 100-YEAR HGL
-------.
Y:\3736·Willlamsgat~\Oralnage\J7J6-0iLN. IOOYR_HGL.dwg, 02/15/2005 11:00:44 AM, llBEM/ip lilolosmart 1215 series, 1:43.6204
Inlet1 I4
RIM I 311.30 f't
SuMp : 307.60 f't -
------------------·-----· -
. -------.. -
--.. __ --------·-----·-· ----------------.
····· -· ------. -
_\\ __
-.. -----· ---
Pipe: I4-I3
Up Invert: 307, 70 f't
Dn Invert1 306.15 f't Length: 193.00 f't
Section S ize: 19x30 inch
,_ -. -
' --I
--
"
HANCOCK LOOP SOUTH 100-Y[AR HGL .. -···--·-. . ~-?t-;------~---~c:-~--~~~~~~--· -----~?J.JJt ___ -;.t,;-·· ---·--.. ·--~~.u~~Si~,;t,t £.•v·;~ -·· --~~~H Ft . -. u-__ ·. ---~7.2' Ft -~'P' ~Jll.Ft4_ ~ 312·4{',t ----~"°:jdf:jt --. --------v r. _ t:;.~~a?JFE-=--~ _::~-[ · =-= ···· ·=: .. · ... ---. :-~ -;=-:;Iir-t-~?.~-.... _ ~---.--~--------\----~----·------. --~~~¥~!--~-~l;j!f!1·t .. -~f~tJ__ ---· -~~(~··=. r;~!f."!11:. fl "\. . ---·--~ •• tt•3• ""'"' . . . ·-~_Inc;, B't:! ti.~ Inc;, ------. ~ =' {,t,;, ft ... · •• ,•1ncti ~~~a ~~~H -.. _ ·-... _ -:-. ---~t~-~~~-___ '~.~-l!~4C lrlCh ~·!f.o:i2~~.2 Inc;, . --• tS:"i~ "'°' --. Y:\3736-wm.amsg"tl!\Orainage\J736-0iLS_JOO~HGl.dwg, Ol/lS!Zoos U:04:J5 AM, \IBEN\hp PhotDsmatt lllS series, l:9S.38zz -·--··-....._ ._
I ..._
J , ~ .• ,. / ___ ·_-_._--_~-_ .. '_,~\-~\_.r,_·:_~_.:_·~-,;~1~,r~·~;;;·;;:~~:· ® _ --- ---r--------------r -----~--------~---- ---:-------r -- -----7""" ----:-~--~~---=-~~-=:-,.-,-~---~:-=~-~~-=-~=~---.:r·.: ',
I <~ ------------"--------------------------· -------------------~---------------------------------·---------------------------------•
I I i \ -----------f . ! 1
: / / l! f ~ : : 1·c o,cR ETE Cl :t :~~~-/--~~~~--------_-·-=~~-0-i~:~-=~-~ [~-~~-~~=--~~-l----~~-~~-:J-~---~=----------1 --------------1 --------------~------------T--------------------__/ ii
1 I :~ '' .... £. ........ -0 ··--., -----L._ .. -. ·-~. I ------I ;1 I I
<o""'l "'""\'u@--><?, '(~ ·i~-<'--. ········-______ H_At!~~{.il~~~~AY~-Qf<}_f!__ ., ·' -----+---·---~~~----~=-~~~-~~-~~=~-/_~~::,~:,~;:=-~·1 1t
v·
-(
(}':
-1
Ii\
'>
j i \ \II . ~ <>------------~------r-· --,--------------o ------::=:::::::----... ~ . f . : \ \ ~ : 10,,~-------~~~:!~~-----------!-------------t ------------+------------~-------------!-------------~---------~-~:~:~-=:-~----,-~~-------0 -r --~. )-i
1.1 . --- ------.JJi'. :.
1.1 I t; 1. 1.. ---:. ::: -------~:~--~~=-; --. ·--J . ~ .~-'>---·-~ --0?~
~! nf1c ..i.L 1oll'CTIO'\:ROX ': j I
1
1 ! : 9 :------------·., 1 'O
l : : I ! l •:: : ! ? : '\J .
I I I I I ! ! : :: ~-l -----------l--_! I : o : : : I ' I ; I o i I i i ii
I ! \ \ :.~~~~~~~:~:~~~:~-~~:~~/~,' -~-~~~i r-~---··--j~
: ! 1 n-n·p 1c,,?n.:-.:cno~oox ; 1 / ,~ 1 !, l ! !!
:--·-:-----. l ! : I j I ; / ! : I I I I l : I I
I ::: I ' I I I ' t ' j ' I ,. I I • I ·:
, I j I I ' 1 I j / I : i 1 1 ' : : I :
: • : I ! I I I I .. ---,-------.... /I ! ,+--------~ ~ : : : ! :
I I I I I I I ' --' -, ' I I ' I . 1-·-. ---------.. ,_,
I ), : I ' I ' I I / l .... 1 ; I : : I : :1 I , L __ . ____________ . .J . \ L. ________ ..!, ____ ·-------1 -------------~-------------r------------.!.------------1 -· __ .. / /,,. -·-........ v ...... \ : ! ! : ~, ~ I ! ! ! :
L-----··--·-----...-i ~--:--o----~~;:-c;-t£,-..: _________ L ______ 1___ ---_L_ ~]·._\ \ i i 1 l ! §!~~i 1 !i !
;._____ ______ ___.,, · SHELBEA couRT r----·---------1 1 : : 1 ·~ : : : :
1 SP.ELBEJ1 DR IV E -4-, _ __ ---------.;;-;;;;i;-,---o<-w•v---------------------------;---:--------:-++, ---------1 -~-1 >-z ·~-!__:, ________ _:~_1 c~o· ntii.if-OF.:w;~·-; -.. r:-~ "' I t ··-------------1 I I ) 9 0 1. 6 ' :: I
I ' -l l l ~'C\1.ET ~ j I j / I .,_!~ \ '., 1, I r--· ------.. -.. ·-·---G-.• , 1 //,--0--------r ----------1-------·r-· ----· --r------· r--·-·-.. -· --T--<l·-.. ,"" / / 1 ; : ,/ 1 , \. \\ 11 1
c----------------·: J'· •! f [-----------:-------------:------------:------------:------------~--------------:---',,, __ "1_------;< 1 ! i /,--'./l ; )\ \ ii ,:
! I I ,1 I I I I ~ ....... __ :.. ______ .... " : I : -----~ , I t __ L ::
i, l "r.\Uh I ' .. .. I I ! -· I ' J I ~. -•' I
I I I I : : l I I I I \ ', I i--:-I , I ! ---~-+i-_I
'. _,!::::.-----~·-.... -i:--\ ~ ! '1 '1 ·, i 'i. '. ! ; ! \ \ /
1
/ !I 1 r : 1 1 , .. : , : \ /", --,, :: I
':, I ! I ~ I \ ...... I ! I \1 '....._ ,..,,.-"-...., / 1J I
I I t I I I i \_ I 1 I I'\ --i--3/ 1 1 ~: ! I ~~==~~~=~~~=~~=~~=~~~=j=~=~=j~==~~~~.'i l 1 1 '--1:-~/''·,,, ii L -L ~--------:_j 1vr-· J J.n ·p1c;.~,·n.;..;cn o~oo:( ! 1 , , , , • • .. ,.
: : : : \ I I : ! I ! / : "-il :
! ! ! f ! I I I ; : 11 I 1:"1
: : l I I I i .-'I
l i j I I \ ! I i i j l I I ! __ .. ______ J i j, -~---------------------t-~=--~~~~--~~-~==~ .. Vi ,1 ·.·-··--r/ ~~~·-=~·::j :·:::::::·:::t:=:·:-.. t .... ·::t=~~L~~·:,:;:;~Q::~·::j~~==:::~:=··--=:~=:1-'1:
'• ,.:.-. ...,.~-----·-----------------------. ------·-.-.... ----•··-·--------r \ \
1/'1 ~ llU-L$'1Xt.ET ~0' Ri04'T .. ·Cf-Y.'AY --------~ \ \ :• . : __ /-_ /--\_ -<~:------1::~-~~---~~~-r~~~:-~=-~ ~r~-~=~~:-~r ~~-=:-~=r ---~~~-~~-~-~I-~~:-~~-~ ~-~~:r~-~~:=:_)-==~---~~~-f -~~----------1 -------------\\:------------~\-~-----------~\1 l 'i
('j / -----------i j . I j I : i i 1 I \ ' \ l j !
I I I I • I I ' ' ' , I I 11 '
I I I I I I I ' I ~ I I I I I
I l ,' l I ' i i i i ! I 1' ii \ ',\ ii I
I I I I I I ' ' I ' I I ,. I L -L~=:~--~-2~~=~-:=~~-=~~t~-----~-~~-1-~:=~~---r-~~-=-:::t-_-~=~·~-~t=~-:=-j_=---~=~~~t-~-~-=---~1 ~---=-~~J==~---=t=---~=~~---1 ~=~~=~~-=\=--1JJ
)
DETENTION BASIN ANALYSIS
t )
Time
(min)
0
1
2
2-Year
Storm
0 .00
6 .23
12.47
Pre-Development
Outflow Hydrograph
(Cubic Feet per Second)
5-Year 10-Year 25-Year
Sto rm
0 00
7 .58
15.17
Storm
0 .00
8.51
17 03
Storm
0.00
9.72
19.45
50 -Year 100-Year
Storm Storm
0.00 0.00
10.99 11.48
21.99 22 .95
3 18.70 22.75 25 .54 29 .17 32 .98 34.43
4 24 .93 30.33 34.05 38 .89 43 .97 45.91
5 31.17 37 .92 42.57 48 .62 54.96 57.38
6 37.40 45 .5 0 51 .08 58 .34 65.96 68.86
7 43 .64 53 .08 59 .59 68.07 76.95 80.34
8 49.87 60.66 68 .10 77.79 87 .94 9 1.82
9 56.10 68 .25 76 .62 87.51 98.94 103.29
: = 111=::: : :§.g\i4 ?J!}!%?i §~::: .:: ::§@@§:f]:·:: ::ez;24 :rm::=:rnq~;~~:J :rnMnzz:r
1 1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Williamsgate S ubd ivision
Job # 000886-3736
59.22
56.10
52.99
49 .87
46.75
43 .64
40.52
37.40
34 .28
31.17
28.05
24 .93
2 1.82
18.70
15.5 8
12.47
9 .35
6.23
3.12
0 .00
72 .04
68 .25
64.46
60.66
56 .87
53 .08
49 .29
45 .50
41 .71
37 .92
34 .12
30 .33
26 .54
22.75
18.96
15.17
11.37
7.58
3.79
0 .00
80 .87
76 .62
72 .36
68.10
63.85
59 .59
55 .3 4
51.08
46.82
42 .57
38 .31
34 .05
29.80
25.54
21 .28
17 03
12 .77
8.51
4 .26
0 .00
92 .37
87 .5 1
82 .65
77 .79
72 .93
68 .07
63 .20
58 .34
53.48
48.62
43 .76
38.89
34.03
29.17
24 .3 1
19.4 5
14.59
9.72
4 .86
0 .00
104.43
98 .94
93.44
87 .94
82.45
76 .95
7 1.4 5
65.96
60.46
54 .96
49.47
4 3.97
38.47
32.98
27.48
2 1.99
16.49
10.99
5.50
0 .00
Project Engineer: Lee Adams
Calculations: L . Brooks
109.03
103.29
97 .55
9 1.82
86 .08
80 .34
74.60
68.86
63 .12
57.38
5 1.65
45 .91
40 .17
34.43
28.69
22.95
17.22
11.48
5.74
0 .00
6/27/2005
)
Tim e 2-Year
(min) Storm
0 0 .00
1 6 .99
2 13.98
3 2 0 .97
4 27 .96
5 34.95
6 41 .94
7 48 .94
8 55.93
9 62 .92
::,:·: :}:10.]J' ::1::;:]:;:~~'.9tl
11
12
1 3
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Williamsgate Subdi v ision
Job# 000886-3736
66.41
62 .92
59.42
55 .93
52.43
48 .94
45.44
41 .94
38.45
34 .95
31.46
27 .96
24.47
20.97
17.48
13.98
10 .49
6 .99
3 .50
0 .00
Post-Developmen t
Detention Inflow
(Cub ic Feet per Second)
5-Yea r 10 -Yea r 25 -Ye ar 50 -Y ea r
Storm Storm Storm Storm
0 .00 0 .00 0 .00 0 .00
8.50 9.54 10 .90 12.32
17.00 19.08 21 .79 24 .64
25 .50 28 .62 32.69 36 .95
34.00 38 .16 43 .5 9 49 .27
42.50 47 .71 54.49 61 .59
51 .00 57 .25 65 .38 73 .91
59 .50 66 .79 76 .28 86 .23
68.00 76.33 87 .18 98 .55
76 .51 85 .87 98 .07 110 .86
::::::· t 85H:H t:i:: :::t95:!4.it :: H0.8'.97 : : .=@g?@§J:: .·.···.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·-:·· ... :.:-:-:-:··-:·:-:-:-:·:-:-:-· ·.·.·.·-:-:-:-:-:-·-:-:-:-:-:-:-:-:-·-·.·.·.·.··.···
80 .76 90 .64 103 .52
76 .51 85.87 98 .07
72 .26 81 .10 92 .62
68.00 76 .3 3 87 .18
63 .75 71.56 81 .73
59 .50 66 .79 76.28
55.25 62 .02 70 .83
51 .00 57 .25 65 .38
46 .75 52.48 59.93
42.50 47 .71 54.49
38 .25 42 .94 49 .04
34 .00 38 .16 43 .59
29 .75 33 .39 38 .14
25.50 28 .62 32 .6 9
21 .25 23 .85 27 .24
17.00 19 .08 21 .79
12.75 14 .31 16 .35
8.50 9 .54 10.90
4.25 4 .77 5.45
0.00 0 .00 0 .00
Project Engineer: Lee Adams
Ca l culations: L. Brooks
117 .02
110 .86
104 .7 0
98 .55
92 .39
86.23
80 .07
73.91
67 .7 5
61 .59
55.43
49 .27
43 .11
36.95
30.80
24.64
18.48
12.32
6.16
0 .00
100 -Y ea r
Storm
0 .00
12.86
25 .72
38 .58
51 .45
64.31
77 .17
90 .03
102 .89
115 .75
::t1:4&m1:::
122.18
115 .75
1 09.32
102.89
96 .46
90.03
83 .60
77.17
70 .74
64 .31
57 .8 8
51.45
45 .01
38 .58
32.15
25 .72
19.29
12.86
6.43
0 .00
6/27/2005
Time
(min)
0
2-Year
Post-Development
Detention Outflow
(Cubic Feet per Second)
5-Year 10-Year 25-Year
Storm Storm Storm Storm
0 0.00 0.00 0.00
5.18 5.41 5 .58 5 .80
2 6 .61 7 .34 7 .87 8 .57
3 9 .18 10 .74 11 .86 13 .37
4 12.93 15 .68 17 .65 20 .32
5 17.86 22.09 25 .14 29 .27
6 23 .81 29.78 34 .07 39 .84
7 30.61 38.45 44 .05 51 .55
8 38 .00 47.77 54 .70 63 .93
9 45 .79 57.45 65 .69 76 .60
10 53 .77 67 .28 76 .77 89.30
50-Year 100-Year
Storm Storm
0 .00 0 .00
6 .03 6 .12
9.32
15.02
23 .23
33 .75
46 .08
59 .63
73 .82
88.24
102 .61
9 .61
15.66
24 .37
35 .51
48.52
62 .76
77 .65
92 .73
107 .73
11 58 .12 72 .28 82 .14 95.08 108 .74 113 .98
:::·m?.rn:::: ::::::, ?~M§P ::t t t:a :~tt:::H::r:§8~~P :-:::-::,::::::~§i@,1 ::::: ::a:o~:§§?. :111tt$?t
13 59 .67 73 .26 82 .62 94 .80 107.53 112 .38
14 58 .36 71 .29 80 .17 91 .69
15 56 .30 68.50 76 .85 87.67
16 53.78 65 .21 73 .03 83 .16
17 50.97 61 .64 68.93 78 .36
18 47 .99 57 .90 64 .66 73.42
19 44 .90 54 .06 60 .31 68 .39
20 41 .76 50 .17 55 .92 63 .34
21 38 .58 46.27 51 .51 58 .28
22 35.40 42.36 4 7 .11 53.23
23 32.22 38.47 42 .72 48 .20
24 29 .05 34 .60 38.36 43 .21
25 25 .91 30 .76 34 .04 38.27
26 22 .80 26 .96 29 .77 33 .38
27 19 .73 23 .22 25 .57 28 .57
28 16.71 19.54 21.44 23 .85
29 13 .77 15.96 17 .41 19.24
30 10.91 12.48 13.51 14.79
Williamsgate Subdivision
Job# 000886-3736
Project Engineer: Lee Adams
Calculations : L . Brooks
103.71
98 .96
93 .71
88 .19
82 .53
76 .81
71 .06
65 .31
59 .59
53 .89
48 .24
42 .64
37 .10
31 .66
26.31
21 .11
16.08
108 .29
103.25
97 .72
91.92
86 .00
80 .01
73 .99
67 .99
62 .00
56.05
50 .14
44.29
38 .51
32 .82
27 .24
21 .80
16 .56
6/27/2005
-) Outlet Control
Depth Velocity Outflow
(ft) (ft/s) (cfs)
0 .0 0 .00 0 .00
0 .5 2 .12 19 .09
1.0 3 .00 54 .00
1.5 3 .67 99 .20
2 .0 4 .2 4 152 .74
2 .5 4 .74 213.45
Q = 3Ly"(3/2)
Q => capacity in cfs
L => length of th e opening which water enters into the weir
y =>total depth of water or head on the weir
L=
y=
18 ft
1.5 ft
Omax = 99.20 cfs
Outflow vs. Depth
y = 86.48x -18.353
-~,..__...._,,._.....,~..,. .... -;,... ......... ___ ~ ~..., .............. ,,..... ....... ,...,-.. ,. ......... .,.........,~ ... __.~.-~ ..... -.... 1
~ ~ ~ 20 0 -i-~~--j-~~-t-~~-~~~-t~~~:--~----<
(.)
-; 150i-~~--j-~~-t-~~-+~----:::__,.~~----1f--~----'
0 s 100
~ 50 -1-~~--1-~~~~~-+~~-+~~-..jl---~---' 0
Williamsgate Subdivis io n
Job# 000886-3736
o-1-... ~+-~~+-~~!--~___jf--~~~~......J
0.0 0.5 1.0 1.5 2 .0
Depth (ft)
Project Engineer: Lee Adams
Calculation s: L. Brooks
2.5 3.0
6/17/2005
) Detention Basin
Elevation Depth Area Storage
(ft) (ft) (ft £) (ft J)
303 15 0 0 0
304 .0 0 .5 12847 3212
304.5 1 .0 '137})5 9872
305 .0 1.5 ; 14743 17007
305 .5 2.0 15742 24628
306 .0 2 .5 16741 32749
Depth vs. Storage
y = 7E-05x + 0 .1801
3.0 ................................................... ,,,,,,., """""'"'""''''"""''"''''"" , ...................................... ..
-2.5 -j---t---t----1----1---t---+:...ai;o..-1
.::::: 2 .0 ' -:5 1.5 +---+---t-----1f-=-fll"=-t---l----+----1 a.
Q.) 0 1.0 +---+---=-~=---11-----1-----+---+--~
0.5 +-----~'F----t----1-------l----+---+---l
Williamsgat e Subdivision
Job# 000886 -3736
0 5000 10000 1500 0 20000 25000 300 00 35000
Volume (ft3)
Project Engineer: Lee Adams
Calculations : L. Brooks
6 /27/2005
( )
Depth
(ft)
0 .0
0 .5
1 .0
1.5
2 .0
2.5
Storage Indication
Storage Outflow 2S/t.t -0
(cf) (cfs) (cfs)
0 0 .00 0 .00
3212 19.09 87 .97
9872 54 .00 275 .08
17007 99 .20 467 .69
24628 152 .74 668 .20
32749 213.45 878 .17
2S/Lit-O vs. Depth
y = 361 .38x -55 .543
1 000 .. ,,_._. ______ .,,_"'" .-.-.v.--.-.-. .. .., ..... .,,~ .. -------~-------------·-.---~------~-
2S/~t + 0
(cfs)
0 .00
126 .15
383 .08
666.10
973.67
1305.08
900 -!---t----1---+----+-----+------!
800
~ 700 -1---1-----1---+----b.~---+------!
~ 600 -1---t-----J---+--,,,"-+-----+------!
0 500
I ... ...52--400 +---+--__;f--Jl//IJll!C_f---~---l---
(j) 300 +----t---~~--J----+---1--___;
N
2 00 +---+--~~---+----+----1---
100 -1---~-,:_...--+----+----1----l---; r 0 ---i
0 .0 0 .5 1.0 1.5
Depth (ft)
Depth vs. 2S/Lit+O
2 .0
y = 0 .0018x + 0 .1896
2.5 3.0
3.0 ............................. [._ ............................................................ _. ............................ ., ........................... ., ................................ :
2.5 -
g 2 .0 -
-:5 1.5 -l----+---t----h._."""-1----+---1-----:
a.
Q)
Q 1.0 +----!-----=-~
Williamsgate Subdivision
Job# 000886-3736
0 .0
0 200 400 600 800 1000 120 0 140 0
2S/pt+O (cfs)
Project Engineer: Le e Adams
Calculations : L . Brooks
6/27 /2005
-~)
~
2-Y ear Storm Eve nt
Infl ow /Outflow Sim ul ation
2-Year Storm Event
vs .storage (2S/6t -0 vs. (Outflow vs. (Inflow-outfl ow)
(inflow•so) eq .) depth eq .) (11+1 2+2 S/6t -0) de pth eq .) cummu la tive
Time In flow Inflow H1 25/M-O 25/t>t + 0 Outflow Outflow Storage
(min) (cfs) (cf) (ft) (cfs) (cfs) (cfs) (cf) (cf)
0 0 .00 0 0 0 0 0 0 0
1 6 .99 419.45 0 .21 2 0 .15 6.99 5 .18 310 .6 0 419.45
2 13.9 8 838 .9 0 .25 33.52 41 .12 6 .61 396 .39 947 .7 4
3 20 .97 1258 .3 0 .31 55 .32 68.47 9 .18 550 .53 1809 .70
4 27 .96 1677.8 0 .39 83 .84 104 .26 12 .93 776 .06 2936 .96
5 34 .95 2097 .2 0.48 117 .26 146.75 17 .86 107 1 .32 4258.14
6 4 1 .94 2516 .7 0 .58 153.82 194.16 23 .81 1428.73 5703 .51
7 48 .94 2936 .1 0.68 191 .95 244 .70 30.61 1836.33 7210 .91
8 55 .93 3355 .6 0 .79 230 .38 296.82 38 .0 0 2280.26 8730 .16
9 62 .92 3775 0 .9 0 268.20 349 .23 45 .79 2747 .23 10224.94
10 69 .91 4194 .5 1 .00 3 04 .81 401 .0 2 53 .77 3226 .17 11672.19
11 66 .41 3984 .8 1 .0 5 324.00 441 .13 58 .12 3487 .28 12430.77
12 62.92 3775 1 .07 331 .28 453 .33 59 .8 0 3588 .08 12718.52
13 5 9.4 2 3 56 5 .3 1 .0 7 33 0 .7 0 453 .6 2 59 .6 7 3580 .0 7 12695 .75
14 55.93 3355.6 1 .05 325 .02 446 .0 5 5836 3501.41 12471 .27
15 52 .4 3 3145 .9 1 .0 3 316 .03 433 .3 8 56 .3 0 3378 .02 12115.72
16 48 .94 2936 .1 1 .00 3 04 .85 417 .39 53 .78 3226 .74 11673.84
17 45.44 2726.4 0 .96 292.19 399 .23 50 .97 3058 .26 11173.52
18 4 1 .94 2516 .7 0 .92 278.49 379 .58 47 .99 2879.32 10631 .95
19 38.45 2307 0.88 264 .01 358 .89 44 .90 2694 .16 10059.59
20 34 .95 2097 .2 0.84 248 .91 337.42 41 .76 2505.47 9462 .67
21 3 1.46 1887 .5 0 .80 233 .28 315 .33 38 .58 2315.01 8 844 .71
22 27 .96 1677 .8 0 .75 217 .16 292.7 0 35.40 2123.94 820 7 .5 0
23 .. 24 .47 1468.1 0 .71 200.57 269 .59 32 .22 1933.09 7551 .63
24 2 0 .97 1258 .3 0 .66 183 .50 246 .01 29 .0 5 1743 .10 6 876.88
25 17.48 1048 .6 0 .61 165.94 221 .95 25.91 1554.52 6182.41
26 1 3 .98 838 .9 0 .56 147 .83 197 .39 22.8 0 1367 .88 5466 .78
27 10.49 629 .17 0.51 129 .15 172 .30 19 .73 1183 .75 4728 .08
28 6 .99 419.45 0.46 109 .81 146 .62 16 .7 1 1002.82 3963 .78
2 9 3 .5 0 2 0 9 .72 0.40 89 .75 120.30 13.77 8 25 .96 3 170 .6 8
30 0 .00 0 0 .34 68 .85 93 .24 10 .91 654 .36 2 344 .72
------·---------------------------·· ----·----·-------·------I
Inflow/Outflow Simulati o n I
2 -Y ear S t orm Eve n t I
····-···--·····----·-------···--·--------------·--··-------····--··----------·-··1 I
Vi" 60 .00 .....
.2.
Q) 40 .00 .....
<ti ...
~
..2 20.00
1.1..
0 .00 -
W illi amsgate S u bdivision
Job # 000886-3736
0 10 20
Time (min)
- --
Project Eng ineer: Lee Adams
Calculations : L. Brooks
I
i - ---·· -1 i
I l I 'i---·---·--I I ------·-· -I -Infl ow ·1 -I -:-.:':~~-t!l '2".':'J I
I !
3 0
H
(ft)
0
0.21
0 .28
0 .34
0.41
0.49
0.59
0.69
0 .79
0 .90
1 .0 0
1 .08
1 .11
1 .11
1 .09
1 .0 7
1.03
1 .00
0 .96
0.92
0 .87
0 .83
0.78
0 .74
0 .69
0.64
0 .59
0.54
0.49
0.44
0.38
6 /27/2 005
l )
r
!
\
\
5-Year Storm Event
Inflow/Outflow Simulation
5-Year Storm Event
(depth vs. (2S /tit -0 vs . (Outflow vs . outflow)
(inflow'60) stora ge eq .) depth eq .) (11 +12+2S/ti t -0 ) depth eq .) cu mmulat ive
Time
(min)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Inflow Inflow H1
(cfs) (cf) (ft)
0 .00 0 .00 0.00
8.50 510 .04 0 .22
17 .00 1020.07 0.26
25 .50 1530.11 0 .34
34 .00 2040 .14 0.44
42 .50 2550 .18 0.55
51 .00 3060 .22 0 .67
59 .50 3570.25 0 .80
68 .00 4080 .29 0 .92
76 .51 4590 .32 1.04
85 .01 5100 .36 1.16
80 .76 4845 .34 1.21
76 .51 4590.32 1.23
72 .26 4335.31 1.23
68 .00 4080 .29 1.20
15 63 .75 3825 .27 1.17
16 59 .50 357 0 .25 1.13
17 55 .25 3315 .23 1.09
18 51 .00 3060 .22 1.05
19 46 .75 2805.20 1.00
20 42 .50 2550 .18 0 .95
21 38 .25 2295.16 0 .90
22 34 .0 0 204 0 .14 0 .85
23 29 .75 1785 .13 0 .80
24 25 .50 1530 .11 0 .74
25 2 1.2 5 1275 .09 0 .69
26 17.00 1020.07 0 .63
27 12 .75 765 .05 0 .57
28 8 .50 510.04 0 .51
29 4 .25 255 .02 0.44
30 0 .00 0 .00 0 .38
90 .00
80 .00 .
2S/M-0
(cfs)
0.00
22.44
40 03
67 .59
102 .90
14 3.62
187 .50
232 .61
277.47
321.09
362.90
383 .35
389 .77
387 .33
379 .35
367 .92
354 .27
339 .15
323 .01
306 .10
288 .56
270.47
251 .85
232.71
213 .03
192 .77
171.89
150 .32
127 .99
104 .77
80 .56
2S/6.t + 0
(cfs)
0.00
8 .50
47 .95
82 .53
127 .09
179.40
237 .12
298.00
360 .12
421 .98
482 .60
528 .67
540.61
538 .53
527 .59
511 .11
491 .17
469 .0 3
445.41
420 .77
395 .36
369.32
342.72
315.60
287.96
259.78
23 1.02
201.64
171.58
140 .74
109 02
Outflow Outflow
(cfs) (cf)
0 .00 0 .00
Storage
(cf)
0 .00
5.41 324 .81 5 10.04
7.34 440 .67 1205 .3 0
10 .74 644.41 2294 .7 4
15 .68 940 .59 3690.47
22.09 1325 .55 5300 06
29.78 1786 .95 7034 .73
38.45 2306 .90 8818.03
47 .77 2866 .07 10591.42
57.45 3447 .22 12315.67
67.28 40 37.02 13968 .80
72.28 4336 .51 14777.13
73.87 4432 .02 15030. 94
73 .26 4395.55 14934 .23
71.29 4277.35 14618 .97
68 .50 4109 .7 5 14166.89
65 .2 1 39 12 .6 8 13627 .39
61 .64 3698.2 5 1302 9 .94
57 .90 3473.7 4 12391 .9 1
54 06 3243 .58 117 23 .37
50.17 30 10.48 11029 .97
46 .2 7 2776.17 10314.65
42.36 254 1.77 9578 .63
38.47 2308.10 8821 .9 9
34.60 2075 .80 8043 .99
30 .76 1845.45 7243 .28
26.96 1617 .66 6417 .9 0
23.22 1393 .1 0 5565 .30
19 .54 11 72.62 4682.24
15 .96 957 .35 3764 .6 4
12.48 748 .83 2807 .29
Inflow/Outflow Simulation
5-Year Storm Event
1
-!
Cil 10.00
'.§.. 60 .00
.s 50 .00
~ 40 .00
~ 30 .00
LL 20 .00
···--·-- . -·------·--·--------------·---I
...:....::-i;·ri;;.,;. -'i
-=~~~~?~I 1
Williamsgate Subd ivision
Job # 000886-3736
10.00
0 .00
0
I -~---~ .~~----:-----··· :-~-=-------_ . -~ =-~-·= 1
10 20
Time (min)
Project Engineer: Lee Ad ams
Calculations : L. Brooks
30
H
(ft)
0 .00
0 .22
0.29
0.36
0.45
0 .56
0 .67
0 .79
0.92
1.04
1.16
1.2 6
1.28
1.2 8
1.25
1.22
1.18
1.14
1 09
1.04
0 .99
0.94
0.88
0.83
0 77
0.7 2
0.6 6
0 .60
0.54
0.48
0 .42
6/27/2 005
)
,-
(inflow•Go)
Time Inflow Inflow
(min) (c fs) (cf)
0 0 .00 0.00
1 9.54 572.47
2 19.08 1144 .94
3 28.62 1717.42
4 38.16 2289.89
5 47 .71 2862.36
6 57.25 3434.83
7 66.79 4007 .30
8 76.33 4579 .78
9 85.87 5152 .25
10 95 .4 1 5724 .72
11 90.64 5438.48
12 85 .87 5152 .25
13 81 .10 4866 01
14 76.33 4579 .78
15 7 1.56 4293 .54
16 66 .79 4007 .30
17 62 .02 3721 .07
18 57 .25 3434 .83
19 52.48 3148.60
20 47 .7 1 2862 .36
21 42.94 2576 .12
22 38.16 2289 .89
23 33 .39 2003.65
24 28 .62 1717.42
25 23 .85 1431.18
26 19 .08 1144 .94
27 14 .3 1 858 .71
28 9.54 572.47
29 4 .77 286 .24
30 0 .00 0.00
100 .00
(i) 80 .00 -~ 60.00 Q) -ro ..... 40 .00 :;:
0
u. 20.00
0 .00
Will iamsgate Subd iv ision
Job # 000886-3736
10-Year Storm Event
Inflow/Outflow Simu lation
10-Year Storm Event
(depth VS. (2S/at -0 vs. (Outflow vs . outflow)
storage eq .) depth eq.) (11+12+2S/a t-0) depth eq .) cum mulati ve
H1 2S/t.t-0 2S/t.t + 0 Outflow Outflow Storage
(ft) (c fs) (cfs) (c fs) (cf) (cf)
0 .00 0 .00 0.00 0 .00 0 .00 0 .00
0 .22 24 .02 9 .54 5 .58 334 .73 572.47
0 .28 44 .52 52 .6 5 7 .87 472 .06 1382 .6 9
0.36 76.02 92 .22 11 .86 7 11. 72 2628 .04
0 .47 115.94 142 .81 17.65 1059.12 42 06 .21
0 .60 161 .56 201 .82 25.14 1508 .68 600 9.44
0 .74 210.29 266.51 34 .07 2044 09 7935 .59
0 .87 259 .95 334.32 44 .05 2642.89 9898 .81
1.01 308.94 403 .07 54 .70 3281 .88 11 835 .70
1.14 356 .26 47 1.14 65 .69 3941 .22 13706 .06
1.26 401 .37 537 .54 76 .77 4606 .34 15489.57
1.3 2 422.43 587.43 82 .14 4928 .30 16321.71
1.34 42 8 .09 598 .94 83 .6 0 5016 .18 16545 .65
1.33 424 .29 595.06 82.62 4957 .20 16395.48
1.30 4 14 .74 58 1.72 80 .17 4809 .98 1601 8 .06
1.27 40 1.68 562 .63 76 .85 4610 .95 15501 .62
1.22 386.41 540 .03 73 .03 4381 .90 14897 .97
1.18 369 .69 515.22 68.93 4135 .65 14237 .14
1.13 351 .96 488 .96 64 .66 3879.74 13536 .33
1.08 333.47 461 .69 60.31 3618.63 12805 .18
1.02 314.34 433 .65 55.92 3355 .00 12048.92
0 .97 294 .64 404 .98 51 .51 3090 .53 11270.04
0 .9 1 27 4 .38 375 .74 47 .11 2826 .32 10469.40
0 .86 253.57 345 .94 42 .72 2563.17 96 46 .74
0.80 232 .18 315.59 38 .36 2301.72 8800 .98
0.74 21 0 .15 284 .65 34 .04 2042 .59 7930.44
0 .67 187.45 253 .09 29 .77 1786.42 7032 .80
0.61 163.98 220 .84 25.57 1533.97 6 105 .09
0 .54 139.66 187.83 21.44 1286.23 5143 .59
0.47 114 .3 6 153 .97 17.41 1044.48 4 143 .60
0.40 87 .94 119 .13 13 .51 810 .57 3099 .11
----------------------··------·---·---. ------·-·--·--·;
Inflow/Outflow Simulation
10-Year Storm Event
·------------·-·····---------------------···-····-··
0
-----------
10 20
Time (mi n)
Pro j ect Enginee r: Lee Adams
Calcu lations : L. Brooks
.. --1
I
-1
-----l
30
;-Inflow 1 · I 'I
' 11 I -Outflow _. , I
i
I
I
I
i
I
i
H
(ft)
0 .00
0.22
0 .30
0 .38
0.48
0.60
0.73
0 .87
1.00
1.14
1.27
1.37
1.40
1.39
1.36
1.32
1.28
1.23
1.18
1.12
1.07
1.01
0 .95
0 .89
0.83
0 .77
0 .70
0 .64
0.57
0 .5 1
0.44
6/27/2005
)
Time
(min .)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
25-Year Storm Event
Inflow/Outflow Simulation
25-Year Storm Event
(depth vs . (2S/6t -0 vs . (Ou tflow vs . outflow)
(in now•6o) storage eq .) depth eq .) (11 +12+2 S/6 t -0) depth eq.) cummula ti ve
Inflow Inflow
(cfs) (cf)
0 .00 0.00
10 .90 653 .82
21 .79 1307 .64
32 .69 1961.46
43 .59 2615.28
54.49 3269.10
65 .38 3922.92
76 .28 4576 .74
87 .18 5230.56
98 .07 5884.38
108.97 6538.20
103.52 6211 .29
98 .07 5884.38
92 .62 5557.47
87 .18 5230.56
81 .73 4903.65
76.28 4576.74
70 .83 4249.83
65 .38 3922.92
59 .93 3596.01
54.49 3269.10
49 .04 2942.19
43.59 2615 .28
38.14 2288 .37
32 .69 1961.46
27 .24 1634 .55
21 .79 1307 .64
16 .35 980.73
10 .90 653 .82
5.45 326.91
0 .00 0.00
100 .00
Vi" 'ti 80 .00
~ 60.00
~
~ 40 .00 - - -
LL
0 .00
0.23
0 .29
0 .39
0 .52
0.66
0 .82
0.97
1 .12
1.26
1.40
1.46
1.47
1.46
1.42
1.38
1.33
1.28
1.23
1.17
1.11
1.05
0.99
0 .93
0 .86
0 .79
0.73
0 .65
0 .58
0 .50
0.42
2S/D.t -0
(cfs)
0 .00
26.08
50 .36
86 .98
132 .84
184 .69
239 .50
294.81
348 .89
400 .71
449 .83
471.41
475 .95
470 .35
458.78
443 .67
426.37
407 .66
387 .96
367 .50
346 .38
324 .68
302 .38
279.48
255.94
231 .70
206 .70
180 .84
154 .02
126 .10
96 .89
2Slt.t + 0
(cfs)
0.00
10.90
58 .77
104 .85
163 .26
230.91
304.55
381 .16
458 .27
534.14
607 .75
662.32
673 .01
666 .65
650 .15
627 .69
601.67
573.48
543 .87
513 .28
481 .91
449 .91
417 .30
384.11
350.31
315 .87
280 .74
244.84
208.08
170 .37
131.55
Outflow Outflow
(cfs) (cf)
0 .00 0 .00
5 .80 347 .80
8 .57 514 .01
13.37 802.44
20 .32 1219.40
29.27 1756 .05
39 .84 2390 .17
51 .55 3092 .89
63 .93 3835 .90
76 .60 4596 .27
89 .30 5358 .22
95 .08 5705 .06
96 .31 5778 .88
94 .80 5687.77
91 .69 5501 .17
87 .67 5260.46
83.16 4989.46
78 .36 4701 .73
73.42 4404 .98
68 .39 4103.64
63 .34 3800 .33
58 .28 3496 .64
53.23 3193 .64
48 .20 2892 .10
43 .21 2592 .68
38 .27 2296 .03
33 .38 2002 .87
28 .57 1714 .07
23.85 1430 .79
19 .24 1154.56
14 .79 887 .61
Storage
(cf)
0 .00
653 .82
1613 .66
3061 .11
4873 .95
6923 .65
9090 .51
11277 .09
13414 .76
15463.24
17405 .16
18258 .23
18437 .55
18216 .14
17758.93
17161.40
16477.69
15738.06
14959.26
14150 .29
133 15 .75
12457.62
11576 .25
10670 .99
9740.35
8782 .22
779 3.83
6771.69
5711.44
4607 .56
3453.00
--------------------··---------------------------·--·-------1
Inflow/Outflow Simulation
25-Year Storm Event
---------____ J
I-Inflow '.'.
' I.
i -_ _9~t~o~_! \
0 .00 --!f:::------..,------..,--------"I
0 10 20 30
T ime (min)
------· -----------------·-------__ j
Williamsgate Subdivision
Job # 000886-3 736
Project Engineer : Lee Adams
Calculations : L. Brooks
H
(ft)
0.00
0.22
0 .32
0.41
0.52
0 .66
0 .81
0 .96
1.11
1.27
1.41
1.52
1.54
1.53
1.50
1.45
1.40
1.35
1.29
1.22
1.1 6
1.10
1.03
0 .97
0 .90
0 .83
0 .76
0.69
0 .61
0.54
0.46
6/27/2005
)
(infl ow•6o )
Time Inflow Inflow
(min) (cfs) (cf)
0 0 .00 0 .00
1 12 .32 739 .09
2 24.64 1478 .18
3 36 .95 2217 .28
4 49 .27 2956 .37
5 61 .59 3695.46
6 73 .9 1 4434 .55
7 86 .23 5173 .64
8 98 .55 5912 .74
9 110.86 6651 .83
10 123 .18 7390 .92
11 117 .02 702 1.37
12 110.86 6651 .83
13 104 .70 6282 .28
14 98 .55 5912 .74
15 92 .39 5543 .19
16 86 .23 5173 .64
17 8007 4804 .10
18 73 .91 4434 .55
19 67 .75 4065 01
20 6 1.59 369 5.46
21 ~5.43 3325 .91
22 49 .27 2956 .37
23 43 .11 2586 .82
24 36 .95 2217 .28
25 30 .80 1847 .73
26 24 .64 1478 .18
27 18.48 1108.64
28 12 .32 739 09
29 6.16 369 .55
30 0 .00 0 .00
120 .00
Q) ...
60.00 <1l ....
?: 40 .00 .2 u..
20 .00
0 .00
Williamsgate Subdiv ision
Job# 000886-3736
50-Year Storm Event
Inflow/Outflow Simulation
50-Year Storm Event
2S/t>t + 0 (2S/llt -0 vs . (Outflow vs . (Inflow -outflow)
eq.) depth eq .) (11 +12+2S /t>t -0 ) de pth eq.) cummulative
H1 25/t.t -0 25/t.t + 0 Outflow Outflow Storage
(ft) (cfs) (cfs) (cfs) (cf) (cf)
0 .00 0 .00 0.00 0 .00 0 .00 0 .00
0 .23 28 .24 12 .32 6 .03 361 .67 739 .09
0 .31 56.48 65 .19 9 .32 559 .20 1855.60
0.43 98.43 118 .07 15 02 901 .05 3513 .67
0 .57 150 .42 184.65 23 .23 1394.05 5569 .00
0 .73 208.64 261 .28 33 .75 2025 .10 7870.41
0.90 269 .59 344 .14 46 08 2764 .93 10279.86
1.07 330 .52 429 .72 59 .63 35 77 .54 12688.57
1.23 389 .59 515 .29 73 .82 4429 .31 15023 .77
1.39 445 .81 599 .00 88 .24 52 94.43 17246 .28
1.53 498.85 67 9.86 102 .61 6156 .35 19342 .77
1.59 52 0 .73 739 .05 108 .74 6524.4 1 20207 .80
1.60 523 .95 748.62 109 .65 6579 .23 20335 .22
1.58 516.44 739 .52 107.53 6451 .72 20 038 .27
1.55 502 .81 719 .69 103.71 6222.41 19499.29
1.50 485 .63 693.74 98 .96 5937.41 18820.06
1.44 466 .30 664 .24 93 .71 5622 .30 18056.30
1.39 445 .61 632 .60 88 .19 5291 .15 17238.09
1.33 423.94 599 .58 82 .53 4951 .71 16381.49
1.26 401 .51 565 .60 76 .81 4608 .34 15494.79
1.20 378.41 530 .85 71 .06 4263 .53 14581 .9 1
1.14 354 .70 495.44 65 .31 3918 .81 13644.29
1.07 330 .35 45 9 .40 59.59 3575 .18 12681 .85
1.00 305 .35 422 .74 53.89 3233 .42 11693 .50
0 .93 279 .64 385.42 48 .24 2894 .19 10677 .36
0 .85 253 .17 347 .39 42 .64 2558 .19 9630 .90
0 .78 225.85 308 .60 37 .10 2226 .23 8550 .90
0 .70 197 .58 268 .96 31 .66 1899.30 7433 .3 1
0 .62 168 .23 228 .37 26 .31 1578 .74 6273.10
0.53 137 .64 186.71 21 .11 1266.36 5063 .91
0.45 105.61 14 3.80 16 .08 964.81 3797 .55
----·-----·-·-
Inflow/Outflow Simulation
50-Year Storm Event
·-··-·-·-----·-----·-·-·-··-·--------··--.. --·-· ------·--··--------.. -----~··----·---
0 10 20
Time (min)
Project Enginee r: Lee Adams
Cal culations : L. Brooks
i
I
r-I,; '°;;;--1 1
,::-CJotflowJ I
:
30 i
I
I
i
.. I
H
(ft)
0.00
0 .22
0.33
0.43
0.56
0.72
0 .88
1.05
1.23
1.39
1.55
1.67
1.69
1.67
1.63
1.58
1.52
1.46
1.39
1.33
1.26
1.19
1.11
1.04
0 .97
0.89
0.81
0.73
0.65
0.57
0.48
6/27/2005
' )
100-Year Storm Event
Inflow/Outflow Simulation
100-Year Storm Event
(depth vs . {2SlfS l -0 vs. (Ouiilow vs . (i nil ow-Outli ow)
(inflow·so) st orage eq.) de pth eq.) (11 +1 2+2 SIM -0 ) depth eq .) cum mula tive
Time In flow I nflow H1 2S/6t -0 2S/6 t + 0 Outflow Outflow Stor ag e
(min) (cfs) (cf) (ft) (cfs) (cfs) (cfs) (cf) (cf)
0 0.00 0 .00 0 .00 0 .00 0.00 0 .00 0.00 0 .00
1 12 .86 771 .68 0 .23 29 .0 6 12 .86 6 .12 367 .03 77 1.68
2 25 .72 1543.36 0 .32 58 .82 67.65 9 .61 576 .80 1948.01
3 38 .58 2315 .03 0.44 102 .79 123 .13 15 .66 939 .64 3686 .24
4 51.45 3086 .71 0 .59 157 .10 192.82 24.37 1462.48 5833 .32
5 64 .3 1 3858 .39 0 .76 217.7 1 272.86 35 .51 2130 .36 8229 .23
6 77 .17 4630 .07 0 .93 280 .95 359.19 48 .52 2911 .10 10728.93
7 90 .03 540 1.75 1.11 343 .95 448 .14 62 .76 3765 .87 13219.58
8 102.89 6173.42 1.27 404 .85 536 .87 77 .65 4659 .06 15627 .13
9 115.75 6945 .10 1.43 462 .68 623 .50 92 .73 5563 .89 17913 .17
10 128.61 7716 .78 1.58 517 .14 707 05 107.73 6463 .61 20066 .06
11 122.18 733 0 .94 J..&5 539 08 767 .94 113 .98 6838 .59 20933 .38
12 115.75 6945 .10 1.65 541 .78 777 .02 114 .75 6885 .13 21039 .89
13 109 .32 6559 .26 1.63 533 .54 766 .85 112 .38 6743 .09 20714 03
14 102 .89 6173.42 1.59 519 .13 745.75 108 .29 6497 .18 20144 .36
15 96.46 5787 .59 1.54 501 .18 718.48 103.25 6195 .15 19434.77
16 90 03 5401 .75 1.48 481 .10 687 .66 97 .72 5863 .17 18641 .36
17 83 .60 5015 .91 1.43 459 .67 654 .73 91 .92 5515.45 17794 .10
18 77 .17 4630 .07 1.36 437 .27 620.44 86 .00 5159 .74 16908 .71
19 70 .74 4244.23 1.30 414 .12 585 .18 80 .01 4800 .34 15 993 .20
20 64.31 3858 .39 1.23 390 .29 549 .16 73 .99 4439 .69 15051 .25
21 57 .88 3472 .55 1.17 365 .82 512.47 67 .99 40 79 .30 14084.11
22 51.45 3086 .71 1.10 340 .71 475 .14 62 .00 3720 .16 13091 .52
23 45 .01 2700 .87 1.03 314 .93 437 .17 56 .05 3363 .03 12072 .23
24 38 .58 23 15 03 0 .95 288.42 398 .53 50 .14 3008 .58 11024 .24
25 32 .15 1929.20 0 .88 261 .11 359 .15 44 .29 2657 .54 9944 .8 6
26 25 .72 1543 .36 0 .80 232 .93 318 .99 38.5 1 2310 .74 8830 .67
27 19 .29 1157 .52 0.72 203 .75 277 .94 32 .82 1969.23 7677.45
28 12 .86 771 .68 0 .63 173.46 235 .91 27 .24 1634.42 6479 .89
29 6.43 385 .84 0.55 141 .88 192 .75 21 .80 1308.22 5231 .32
30 0 .00 0.00 0.45 108 .78 148.31 16 .56 993.47 .3923 .09
·-·-----·---------· ·--·-·-----· --·----·-·----·--------·-----------
Inflow/Outflow Simulatio n
140 . 00 ---_________ ,,,, __ --.. -·--·-----------··-···--------------·· .. --.... ,
120 .00
~ 100 .00
0
-; 80 .00 ....
~ 60 .00 ::
::._ 40 .00
20 .00
0 .00
0 10 20
Time (m in)
Wi ll iamsgate Subd ivision Project Engineer: Lee Adams
Job# 000886-3736 Calculations: L. Brooks
30
'
-Inflow
1
-C?utflow_i
...... - -_i
H
(ft)
0
0 .22
0 .33
0.44
0 .58
0 .74
0.91
1.09
1.27
1.44
1.61
1.73
1.75
1.73
1.68
1.63
1.57
1.50
1.43
1.36
1.29
1.22
1.14
1.07
0.99
0 .91
0 .83
0 .75
0 .66
0 .58
0.49
6/27 /2005
<.D
I
N
2'-0" 18'-0"
' I EL=306'-0"
EL=303'-6"
1'-6" t .__-......----------+-------------'
'-o" A-----
ELEVA Tl ON VIEW
@ CONCRETE WEIR
cs
X:\800\3736Wllliamsgate\SHEITT\Phase l\3736DETENTIONBP1.dwg, 06/20/2005 12 :19:08 PM . \WlMIN7\HP LaserJet 4,
1:1.13683
WALL w /30°
N.T.S.
T'rP . CONCRETE
VAU.£Y GUTlER
FLARED
14 BARS 0
12" O.C.E. W.
1'-0"
-l I-
4'-0" 4 '-0"
SECTION 'A-A'
W-INGWALLS
BAFFLE PIER
DETE NTION PLAN & DETA ILS
I
I
I i ci--
:\ i
WILLIAMSGAT 20.27 ACE SUBDIVIS ION
c CRAWFOl<O 0 RES TOT AL
OLLEGE STAllOURNElT LEAGUE N, BRAZOS COU N~~.7 TX
I
';!
\ ".'.
\
I
\
~ ~() ~
\j\ r· .
\
\ v ""'..,,. I I
.~
j
I
·---·-
f
(")
t.ll 1
I
I
I