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DRAINAGE REPORT -ADDENDUM, APRIL 2003
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
INTRODUCTION
The purpose of this addendum is to provide infonnation concerning the revision to Pipe
No. 3 13 of the Castlegate Subdivisioll, Section 3, Phase 2, and to verify that these
revisions do not affect the previous hydraulic analys is perfo1med for this development.
LOCATION AND DESCRIPTION
The previous design of 60" RCP (Pipe No. 313) and Channel No. 4 did not allow enough
room for the proposed 8' concrete walking path th at wi ll be constructed in the Restri cted
Open Space Reserve and drainage easement. By extending the length of the pipe, not onl y
is there more space for th e pathway, but it also wi ll be more aesthetically pleasing from the
street. In order to extend this pipe, a 30-degree bend is needed. The proposed revision to
Pipe No. 313 involves adding 16 feet of pipe, then a 30-degree bend (8 ' in length) and then
and additional 88 feet of pipe. The concrete headwall and rock riprap will be placed at the
end of the pipe as previously designed. Table 1 (fonnerly found in Appendix B of the
original Drainage Report for Castlegate, Section 3, Phase 2, dated July, 2001) below shows
the changes to Pipe o. 313.
TABLE 1 -Revised Pipe Data
Castlegate Subdivision -Section 3, Phase 2
Pipe Data -REVISE D APRIL, 2003
Inlet Outlet 1 O year storm 100 year storm Pipe# Size Length Slope Invert Elev Invert Elev ti't' Actual Flo\ Design Flow v,. Travel Time, lflo I"" Actual Flo._ Design Flow v, .. % Full % Full (in) (fl) (%) (ft) (fl) (cfs) (cfs) (fps) (sec) (min) (cfs) (cfs) (fps)
308A 54 85.0 1.30 303.38 302.28 153.41 14.3 63.8 6 0.10 214.14 14.9 84.8
310 60 134.0 1.10 301.41 299.94 162.51 13.7 58.2 10 0.16 226.54 14.6 73.7
311 60 174.1 1.10 299.84 297.92 162.51 13.7 58.2 13 0.21 226.54 14.6 73.7
312 60 125.0 1.10 297.71 296.34 169.49 13.8 59.8 9 0.15 234.01 14.7 75.8
313 60 *292 0.95 296.24 293.47 251.42 13.5 90.2 22 0.36 351.97 13.2 100.0
309 18 28.1 0.96 305.27 305.00 4.89 7.90 6.0 69.3 5 0.08 6.35 10.26 6.0 92.1
321 27 201 .6 1.00 304.42 302.40 26.60 8.2 75.9 25 0.41 30.80 8.1 91.2
320 27 141 .2 1.00 302.36 300.95 26.60 8.2 75.9 17 0.29 30.80 8.1 91.2
318 36 224.6 0.98 300.16 297.96 48.50 9.6 67.1 23 0.39 65.81 9.7 92.0
317 42 161.6 0.43 297.57 296.88 48.50 7.1 67.1 23 0.38 65.81 7.1 92.4 ---· ----------· ---·-----314 48 39.9 1.10 296.78 296.34 70.82 11 .2 50.4 4 0.06 102.73 12.2 63.7 ----·--- --
319 27 28.3 1.43 301.56 301.16 8.27 7.1 33.4 4 0.07 16.64 8.6 49.0
316 27 28.0 0.54 298.74 298.59 11.40 5.4 52.3 5 0.09 22.20 6.0 87.5
315 30 69.1 0.84 298.36 297.78 22.32 7.5 58.1 9 0.15 36.92 8.0 88.5
*This length includes 8 LF for the 30-degree pipe bend.
Travel Time, luoo
(sec) (min)
6 0.10
9 0.15 f.---
12 0.20 --9 0.14
22 0.37
5 0.08
25 0.41
17 0.29
23 0.39
23 0.38 --3 0.05
3 0.05
5 0.08
9 0.14
,.
'
CONCLUSIONS
The drainage area and the peak runoff flowing into the pipe do not change; therefore, the
increase in length of Pipe No. 313 does not alter the previous hydraulic analysis perfonned
for this development. Please refer to Exhibit B of the Drainage Repo11 for the Cast legate
Subdivision, Section 3, Phase 2, dated July 2001, for the drainage areas for this pipe.
Table 2 in that same report provides the peak runoff values for Pipe No . 313.
4--7--o3
2
TEX CON
General Contractors
Div. of CDS Enterprises, Inc.
1707 Graham Rd. • College Station, TX 77845 • 979-690-7711 • Fax: 979-690-9797
April 7, 2003
Spencer Thompson
Development Services
City of Co llege Station
1101 Texas Ave. South
College Station, TX 77842
RE: Castlegate Subdivision -Section 3, Phase 2 -Coll ege Station, Texas
Dear Mr. Thompson:
The Developer of the above referenced Subdivision is requesting to extend the 60"
diameter storm sewer pipe, (Pipe No. 313), which discharges into the proposed Channel
No. 4 and thence into the existing tributary of Spring Creek. The pipe extension will
allow more area to construct the proposed 8' wide concrete pathway in the Open Space
area that the pipe and channel are located within. The proposed headwall and rock riprap
will be installed at the end of th e pipe as previously shown.
Attached are an Addendum to the Drainage Report and revised plan Sheets 4 and 6 of 13
for this Subdivision for yo ur review.
If you have any questions or need additional information,'pl ease do not hesitate to give
me a call at (979) 690-77 11.
Sincerely Yours,
Joe Schultz, P.E.
Engineering Manager
Attachments
cc: Wallace Phillips
I
\
DRAINAGE REPORT-ADDENDUM, APRIL 2003
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
INTRODUCTION
The purpose of this addendum is to provide information concerning the revision to Pipe
No. 313 of the Castlegate Subdivision, Section 3, Phase 2, and to verify that these
revisions do not affect the previous hydraulic analysis performed for this development.
LOCATION AND DESCRIPTION
The previous design of 60" RCP (Pipe No. 313) and Channel No. 4 did not allow enough
room for the proposed 8' concrete walking path that will be constructed in the Restricted
Open Space Reserve and drainage easement. By extending the length of the pipe, not only
is there more space for the pathway, but it also will be more aesthetically pleasing from the
street. In order to extend this pipe, a 30-degree bend is needed. The proposed revision to
Pipe No. 313 involves adding 16 feet of pipe, then a 30-degree bend (8 ' in length) and then
and additional 88 feet of pipe. The concrete headwall and rock riprap will be placed at the
end of the pipe as previously designed. Table 1 (formerly found in Appendix B of the
original Drainage Report for Castlegate, Section 3, Phase 2, dated July, 2001) below shows
the changes to Pipe No. 313.
TABLE 1 -Revised Pipe Data
Castlegate Subdivision -Section 3, Phase 2
Pipe Data -REVISED APRIL, 2003
Inlet Outlet 10 year storm 100 year storm Pipe# Size Length Slope Invert Elev Invert Elev 1-t-Actual Floy Design Flow V10 Travel Time, tm Actual FIOY Design Flow V 100 % Full % Full (in) (ft) (%) (fl) (ft) (cfs) (cfs) (fps) (sec) (min) (cfs) (cfs) (fps)
308A 54 85.0 1.30 303.38 302.28 153.41 14.3 63.8 6 0.10 21 4.14 14.9 84.8
310 60 134.0 1.10 301.41 299.94 162.51 13.7 58.2 10 0.16 226.54 14.6 73.7
311 60 174.1 1.10 299.84 297.92 162.51 13.7 58.2 13 0.21 226.54 14.6 73.7
312 60 125.0 1.10 297.71 296.34 169.49 13.8 59.8 9 0.15 234.01 14.7 75.8
313 60 '292 0.95 296.24 293.47 251.42 13.5 90.2 22 0.36 351.97 13.2 100.0
309 18 28.1 0.96 305.27 305.00 4.89 7.90 6.0 69.3 5 0.08 6.35 10.26 6.0 92.1
321 27 201.6 1.00 304.42 302.40 26.60 8.2 75.9 25 0.41 30.80 8.1 91.2
320 27 141.2 1.00 302.36 300.95 26.60 8.2 75.9 17 0.29 30.80 8.1 91.2
318 36 224.6 0.98 300.16 297.96 48.50 9.6 67.1 23 0.39 65.81 9.7 92.0
317 42 161.6 0.43 297.57 296.88 48.50 7.1 67.1 23 0.38 65.81 7.1 92.4 ----------· ----· ---... -·-------· --- -
314 48 39.9 1.10 296.78 296.34 70.82 11.2 50.4 4 0.06 102.73 12.2 63.7 -·------------ ---
f---319 27 28.3 1.43 301.56 301 .16 8.27 7.1 33.4 4 0.07 16.64 8.6 49.0
·-316 27 28.0 0.54 298.74 298.59 11.40 5.4 52.3 5 0.09 22.20 6.0 87.5
315 30 69.1 0.84 298.36 297.78 22.32 7.5 58.1 9 0.15 36.92 8.0 88.5
*This length includes 8 LF for the 30-degree pipe bend.
Travel Time, tl1oo
(sec) (min)
6 0.10
9 0.15
12 0.20
9 0.14
22 0.37
5 0.08
25 0.41
17 0.29
23 0.39
23 0.38 ----3 0.05 -
3 0.05
5 0.08
9 0.14
CONCLUSIONS
The drainage area and the peak runoff flowin g into the pipe do not change; therefore, the
increase in length of Pipe No. 313 does not alter the previous hydraulic analysis performed
for this development. Please refer to Exhibit B of the Drainage Report for the Castlegate
Subdivision, Section 3, Phase 2, dated July 2001, for the drainage areas for this pipe.
Table 2 in that same report provides the peak runoff values for Pipe No . 313.
4-7--o3
2
DP-oi-0016005L./.
FINAL PLAT APPLICATION
(check one) Minor _Amending V Final _ Vacating _Replat
The following items must be submitted by an established filing deadline date for P & Z Commission consideration.
MINIMUM SUBMITTAL REQUIREMENTS:
./ Filing Fee of $200.00.
v · Development Permit Application Fee of $100.00 (if applicable).
~Infrastructure Inspection Fee of $300.00 (applicable if any public infrastructure is being constructed.).
/ Application completed in full.
~Thirteen (13) folded copies of plat. (A signed mylar original must be submitted after staff review.)
....::::_One (1) copy of the approved Preliminary Plat and/or one (1) Master Plan (if applicable).
_L Paid tax certificates from City of College Station, Brazos County and College Station LS .D.
L_ A copy of the attached checklist with all items checked off or a brief explanation as to why they are not.
~Two (2)copies of public infrastructure plans associated with tills plat (if applicable).
APPLICANf/PROJECT MANAGER'S INFORMATION (Primary Contact for the Project):
Name br~~\tf~s Lk\ -\~lalliau ~l~ps
StreetAddrcss ~~-0~0Q'e City Col(~ Sta:hE!YJ
State \'X._ Zip Code :J 1£il:S E-Mail Address -----+-------
Phone Number q 1 'I -(i;q 3 -I 1)30 Fax Number j 11 -(,,'10 -{ 4-~ -4 + (,;, 0
PROPER1Y OWNER'S INFORMATION: ~
Name Gv ~]roi<\.Q.., Iwx<di> ~~ J LJ-J .
Street Ad~s SD\D ~LJ<Jt (_,\ v-&.L City Co\ l 9. 9if-Sf-a.J; CLO
State I Y, Zip Code "'] 1. 'D4S: E-Mail Address __________ _
Phone Number CJ lq -l:,43 ..... lCQ?;Q Fax Number q :JC! -V/D-J 4-100
ARCfllTECT OR ENGINEER'S INFORMATION:
Name 1:e XLDV\ -Joe Svkv--\*.:t.-1 P. E · ,
Street Address 11o1 Gca haxn ](~ City ~L(g12f ~fa-h w? .·
State r x z;p Code 11164s= E-Mail Address j oe s~b .c I+ le e ±e u Qtl • '1 t'1
Phone Number VJ.11 ~ l/tO -1J l \ Fax Number q 1C( -fclf_O -'j_1q]
FINAL PLAT APPUCATION I ofJ
TOTAL ACRES OF SUBDIVISION 1$.1o R-0 -W ACREAGE 2 . Sit-TOTAL# OF LOTS l,?
TUMBER OF LOTS BY ZONING DISTRICT Z-.3 I PDD --:ft I I
AVERAGE ACREAGE OF EACH RESIDENTIAL LOT BY ZONING DISTRICT:
Q SL\-1 tpi)-\k ! __ I ----I ----
FLOODPLAIN ACREAGE k , \ \
PARKLANDDEDICATIONACREAGE __ Q ___ ORFEEAMOUNT ____ _
A STATEMENT ADDRESSING ANY DIFFERENCES BE1WEEN 11ffi FINAL PLAT AND APPROVED MASTER
DEVELOPMENT PLAN AND/OR PRELIMINARY PLAT (IF APPLICABLE):
(t
REQUESTED VARIANCES TO SUBDIVISION REGULATIONS & REASON FOR SAME ______ _
Kt{ev= =tu PDD -t\-1Do 1~ SfanJa&Js
TOTAL LINEAR FOOTAGE OF PROPOSED:
__ l'"-"'<Q'-=~-=-· _STREETS
0 SIDEWALKS --~--:--4 l 3' SANITARY SEWER LINES __ (..._(o~q'--~-, -WATER LINES -------=3'""---'lt''-=~'--·~ CHANNELS
_ _,_l-"'-(p-=--7-__,_\ _' _ STORM SEWERS
__ Cf_._CO .......... _' -BIKE I ~sms I PA1HS
NOTE: DIGITAL COPY OF PLAT (IF APPLICABLE) MUST BE SUBMITIED PRIOR TO FILING.
The applicant has prepared this application and certifies that the facts stated herein and exhibits attachea
hereto are true, correct and complete. The undersigned hereby requests approval by the City of College Station
of the above identified final plat.
FINAL PI.AT APPLICATION
SUPPLEMENTAL DEVELOPMENT PERMIT fNFORMATION
development specific site/waterway alterations:
ACKNOWLEDGMENTS:
I, ___ \rJ _ _:_D...:_li_~"-"':;__:c_-~+-''--'~"""~-"-ll-"-'-=--~~2'----' design engineer/owner, hereby acknowledge or affinn lliat:
The infonnation and conclusions contained in ll1e above plans and supporting documents comply wiili ll1e current requirements of
the City of College Station, Texas City Code, Chapter l3 and its associated Drainage Policy and Design Standards.
As a condition of approval of this permit application, I agree to construct the improvements proposed in iliis application according
tl=e documents and the miuire;;_~ f Chaple< 13 of !he College Siation City Code
A~&t~ ------
Property Owner(s) Contractor
CERTIFICATIONS: (for proposed alterations within designated flood hazard areas.)
A. L , certify that any nonresidential structure on or proposed to be on this site as par
of this application is design£.ted to prevent damage to the structure or its contents as a result of flooding from the 100 year storm.
Engineer Date
I, , certify that the finished floor elevation of the lowest floor, including any
..ement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the
latest Federal Insurance Administration Flood Hazard Study and maps, as amended.
Engineer Date
c. L j D~ Y · Schv... l t 1::... certify that the alterations or development covered by this permit shall not
diminish the flood<aIItillg capacity of the waterway adjoining or crossing this permitted site and that such alterations or
development are consistent with requirements of the City of College Station City Code, Chapter l3 concerning encroachments of
floodwa sand offloodway: frin _,_,,,,,, ---(..~OF /~ \\ 7 -7 J _ ol '4-~···*········ .. ~...,IS''•• ----''----------If'----.·· ·.. * .,
Date '-* : ·. * ~ . l.!.: ... £p··-r·sci'.iu'1Ir··~ Sc1Ju.. \.~~o certify that the proposed alterations do not~J?~·~of-ch'e"l"l'p.Qf&u-
e la ederal Insurance Administration Flood Haz.ard Stu~"•. ~ 65889 ,..... .: Ii/ I ,;o ·.-:r~ ~ v. ~ .,, f :;(\ ••.G'/STE.~···',.. ..__, -1..J -~ r ,,~si• ......... ~0J ---/-+----------\\ IONAL <;;;. __ Date ,,,~-
Engineer
D. L .Jose~ y.
flood above elevation lished i
Engineer
Conditions or comments as part of approval:-----------------------------
.::cordance wiili Chapter l3 of the Code of Ordinances of ilie City of College Station. measures shall be taken to insure that dcbri
1rom construction. erosion. and sedimentation shall not be deposited in city streets, or existing drainage facilities.
All development shall be in accordance will1 the plans and specifications submitted to and approved by ilie City Engineer for t11e
above named project. All of ll1e applicable codes and ordinances of ll1e City of College Station shall apply.
J:1'N A' Pf AT A PPI rr A TJ{)N J ofJ
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Col l ege ~t~t i on City (C2)
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'ni'.8 r (~:-~i-. ·'1 1"(; d 1.1 ;~ c)n t h e prop:)ri':y f1)t' i;h ::-:: i".a:-<i ng e n t i.ti.:1 ::~ d escribed ,:\;)l)\/E:;
·_ntlty ~:; I::,-, t ;:: me n t TD x (Ju e o 5 ~. c . ; f' r..J r~t t .. Fer: T c· t ~' J.. D u <:
-C 1) ti'< l I) I.I ;': 0 n I~ 1_ 1. fj i. l. l. ::> : t 0 .0 0
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:
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~02,~;.lj tl .4 :~
This certificate is issued on rea I
estate only. It does not include
minerals and/ or personal property.
SPECIAL CONDITIONS EXIST ON
THIS ACCOUNT! SEE BELOW
**W End o f r~x Cert lf lcatc NN
f ~ppl ica hl c, t h a abov e d escr i.b e d p r or e rty i s rece lvl n g 3 peci~l v~luotlo n
·~s e d un Jts u se . Ad dit i o n ~J.. r ollb ~ck t~xes wh i ch m~y become du e b ~sed o n
: h P. p r o v l s \. 0 n s 1) f t; h ~"} ~ p e c l ·"< l v .:: l u d t i.. o n .:1 r e n o t .i n d i. c .-.1 t e d i. n t; h i :-:; d o c um e n t .
his ce r t if5 c~te does no t c l e a r &bu se of g r~nt e d exe mp tio n s ~s de fin e d i n
. .::; c t i. o n l l . 4 ::~ , : > .'1 r -':: g , ... ci p h ( i. ) 0 f t h =~ r ::: x .-'; ~-f> r o p (~ r 1'; y T .:i >< C r> d ::: .
Date of Issu e : 0 1 /25/01
~queste d by GRE E NS PRAlR i f
··• f8e co ll ect8 d .
..
• (f ~ DEVELOPMENT PERMIT
PERMIT NO. 02-100054
Project: Castlegate
COLllGl STATION FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA
RE : CHAPTER 13 OF THE COLLEGE STATION CITY CODE
SITE LEGAL DESCRIPTION:
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
DATE OF ISSUE: 8/21/02
OWNER:
GREENS PRAIRIE INVESTORS, LTD.
5010 AUGUSTA CIRCLE
COLLEGE STATION, TX 77845
SITE ADDRESS:
2270 GREENS PRAIRIE RD . W
DRAINAGE BASIN:
Spring Creek
VALID FOR 12 MONTHS
CONTRACTOR:
TYPE OF DEVELOPMENT: Full Development Permit
SPECIAL CONDITIONS:
All construction must be in compliance with the approved construction plans
All trees must be barricaded, as shown on plans, prior to any construction. Any trees not barricaded will not
count towards landscaping points. Barricades must be 1' per caliper inch of the tree diameter.
The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate
construction site in accordance with the approved erosion control plan as well as the City of College Station
Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are ineffective
to retain all sediment onsite, it is the contractors responsibility to implement measures that will meet City, State
and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and
establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion
control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original
condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to
adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion,
siltation or sedimentation resulting from the permitted work.
Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced
before any operations of this permit can begin.
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be
taken to insure that debris from construction, erosion , and sedimentation shall not be deposited in city streets,
or existing drainage facilities.
I hereby grant this permit for development of an area inside the special flood hazard area. All development
shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the
development permit application for the above named project and all of the codes and ordinances of the City of
College Station that apply.
Date
Date
General Contractors
Div. of CDS Enterprises, Inc.
· 1707 Graham Rd. • College Station, TX 77845 • 979-690-7711 • Fax: 979-690-9797
August 12, 2002
Brett McCully, P.E.
Asst. City Engineer
City of College Station
1101 Texas Ave. South
College Station, TX 77842
RE: Castlegate Subdivision -Section 3, Phase 2 -College Station, Texas
Dear Mr. McCully:
The final plat for Castlegate Subdivision, Section 3, Phase 2, was approved by the
Planning & Zoning Commission on September 6, 2001. The construction drawings for
the infrastructure were approved on August 8, 2001 and the Development Permit, (Permit
No. 100054), was issued on September 7, 2001. Due to the number of lots still available
for sale, 9 of 25, in Phase 1 of this Section, the Developer, Greens Prairie Investors,
LTD., requests a 12-month extension to the Development Permit. Construction of the
infrastructure for this Phase will be started prior to the end of the 12-month time
extension and the project will be constructed in accordance with previously approved
Final Plat and construction drawings.
If you have any questions or need additional information, please do not hesitate to give
•--- ---" L ("""{)\ £("\/) 7"711 1.-.l\;; a '-'uu G.l :;,, 1 -' J V /v-; 1 •
Sincerely Yours,
Jo Schultz, P.E.
Engineering Manager
cc: Wallace Phillips
•
((~ DEVELOPMENT PERMIT
PERMIT NO. 100054
DP-CASTLEGATE SUB SEC 3 PH 2
COLLEGE STATION FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA
RE : CHAPTER 13 OF THE COLLEGE STATION CITY CODE
SITE LEGAL DESCRIPTION:
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
DATE OF ISSUE: SEPTEMBER 7, 2001
OWNER:
GREENS PRAIRIE INVESTORS, LTD.
5010 AUGUSTA CIRCLE
COLLEGE STATION, TEXAS 77845
SITE ADDRESS:
2270 GREENS PRAIRIE RD W
DRAINAGE BASIN:
SPRING CREEK
VALID FOR 12 MONTHS
CONTRACTOR:
TYPE OF DEVELOPMENT: FULL DEVELOPMENT PERMIT
SPECIAL CONDITIONS:
All construction must be in compliance with the approved construction plans
All trees must be barricaded , as shown on plans, prior to any construction. Any trees not barricaded will not
count towards landscaping points. Barricades must be 1' per caliper inch of the tree diameter.
The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate
construction site in accordance with the approved erosion control plan as well as the City of College
Station Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are
ineffective to retain all sediment onsite, it is the contractors responsibility to implement measures that will
meet City, State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed
areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales
used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed
vegetation be returned to its original condition , placement and state. The Owner and/or Contractor shall
be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery
and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work.
Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced
before any operations of this permit can begin.
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station , measures shall be
taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets,
or existing drainage facilities.
I hereby grant this permit for development of an area inside the special flood hazard area. All development
shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the
development permit application for the above named project and all of the codes and ordinances of the City of
College Station that apply.
Administrator/Representative Date
Owner/Agent/Contractor Date
(('1 DEVELOPMENT PERMIT
PERMIT NO. 100054
DP-CASTLEGATE SUB SEC 3 PH 2
COlllGl STATION FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA
RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE
SITE LEGAL DESCRIPTION:
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
DATE OF ISSUE: SEPTEMBER 7, 2001
OWNER:
GREENS PRAIRIE INVESTORS, LTD.
5010 AUGUSTA CIRCLE
COLLEGE STATION, TEXAS 77845
SITE ADDRESS:
2270 GREENS PRAIRIE RD W
DRAINAGE BASIN:
SPRING CREEK
VALID FOR 12 MONTHS
CONTRACTOR:
TYPE OF DEVELOPMENT: FULL DEVELOPMENT PERMIT
SPECIAL CONDITIONS:
All construction must be in compliance with the approved construction plans
All trees must be barricaded, as shown on plans, prior to any construction. Any trees not barricaded will not
count towards landscaping points. Barricades must be 1' per caliper inch of the tree diameter.
The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate
construction site in accordance with the approved erosion control plan as well as the City of College
Station Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are
ineffective to retain all sediment onsite, it is the contractors responsibility to implement measures that will
meet City, State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed
areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales
used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed
vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall
be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery
and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work.
Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced
before any operations of this permit can begin .
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be
taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets,
or existing drainage facilities.
I hereby grant this permit for development of an area inside the special flood hazard area. All development
shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the
development permit application for the above named project and all of the codes and ordinances of the City of
College Station that apply.
9--07-o I
Date
9-/s-aj
Owner/Agent/Contractor Date
Item
No.
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
31
32
33
34
35
36
37
38
TEXCON GENERAL CONTRACTORS
CONSTRUCTION COST ESTIMATE
CASTLEGATE SUBDIVISION
COLLEGE STATION, TEXAS
SECTION 3, PHASE 2 -23 LOTS
Description
Sitework
Mobilization/Layout
Erosion Control/Seeding
Site Preparation
Topsoil Stripping & Replacement
Excavation /Grading
Lime Stabilized Subgrade
Concrete Laydown Curb
Base Material -6" depth
Asphalt Paving -1 1/2" depth
Storm Drainage
Drainage Pipe -18" RCP -structural
Drainage Pipe -27" RCP -structural
Drainage Pipe -27" RCP -non-structural
Drainage Pipe -30" RCP -structural
Drainage Pipe -36" RCP -non-structural
Drainage Pipe -42" RCP -structural
Drainage Pipe -42" RCP -non-structural
Drainage Pipe -48" RCP -non-structural
Drainage Pipe -54" RCP -non-structural
Drainage Pipe -60" RCP -structural
Drainage Pipe -60" RCP -non-structural
Junction boxes
Inlets 1 O' wide
Inlets 15' wide
Headwalls -60" RCP
Channel excavation
Rock riprap
Water Lines
6" Water PVC CL200 (C900) non-structural
8" Water PVC CL200 (C900) structural
8" Water PVC CL200 (C900) non-structural
Gate Valves -6"
Gate Valves -8"
M.J . Tees -6" x 6"
M.J . Bends -8"
M.J. Tees -8" x 6"
Water Services
Water Tie-in at existing stub out
2" Blow off Assembly
Fire Hydrant Assembly
Estimated
Quantity
1.0 LS
1 LS
3.0 AC
750 CY
2,000 CY
6,070 SY
3,850 LF
4,800 SY
4,800 SY
28 LF
57 LF
344 LF
70 LF
226 LF
127 LF
35 LF
40 LF
85 LF
131 LF
485 LF
5 EA
7 EA
EA
1 EA
250 CY
75 TNS
326 LF
55 LF
1,314 LF
1 EA
2 EA
EA
10 EA
4 EA
14 EA
2 EA
0 EA
4 EA
Page 1 of 2
REVIEWED FOF~
06-Au~-Q cn~JP~.J ' !CF
AUG 0 8 2001
COLLEG r: c, ··: . I
Unit EN Mfa ING ~#}
Price Cost ~-'/' /
$10,000.00
$12,000.00
$3,000.00
$4.00
$3.75
$3.25
$7.50
$6.00
$4.50
Subtotal
$38.00
$48.00
$36.00
$52.00
$52.00
$88.00
$72.00
$86.00
$106.00
$150.00
$130.00
$2,400.00
$3,200.00
$3,600.00
$5,000.00
$5.00
$50.00
Subtotal
$18.00
$30.00
$20.00
$500.00
$600.00
$275.00
$300.00
$300.00
$750.00
$200.00
$450.00
$2 ,200.00
Subtotal
$10,000
$12,000
$9,000
$3,000
$7,500
$19,728
$28,875
$28,800
$21,600
$140,503
$1,064
$2,736
$12,384
$3,640
$11 ,752
$11, 176
$2,520
$3,440
$9,010
$19,650
$63,050
$12,000
$22,400
$3,600
$5,000
$1,250
$3.750
$188,422
$5,868
$1 ,650
$26,280
$500
$1,200
$275
$3,000
$1,200
$10,500
$400
$0
$8.800
$59,673
·f ...
Sanitary Sewer Lines
39 6" ASTM 2261 pressure pipe -structural
40 6" SOR 26 Pipe -structural
41 6" SOR 26 Pipe -non-structural
42 Sewer Services
43 Sewer Services -Finish to exist. line
44 Manholes -average depth 10'-12'
45 Sewer Tie-in at existing line/manhole
46 Modify existing manhole
20
185
268
5
7
2
LF
LF
LF
EA
EA
EA
EA
EA
$30.00
$28.00
$20.00
$750.00
$500.00
$2,400.00
$400.00
$350.00
Subtotal
$600
$5, 180
$5,360
$3,750
$3,500
$4,800
$400
$350
$23,940
Total Sitework $140,503
Total Storm Drainage $188,422
Total Water $59,673
Total Sanitary Sewer ~ _ _,.$;;;;2~3,!,;;,9.;,40;;.,
TOTAL CONSTRUCTION! $412,5381
Engineering and Survey@ 5% $20,627
Page 2 of 2
Contingency@ 5% $20,627 ~--'----'--TOT AL l $453,791 I
REVIEWED FOR
COf\~PLI . 'CE
AUG 0 8 2001
COLLEGC: SI;: 1 .v1\I
ENGINEERIN ~
Drainage Report
for
Castlegate Subdivision
Section 3, Phase 2
College Station, Texas
July 2001
Developer:
Greens Prairie Investors, Ltd.
By Greens Prairie Associates, LLC
5010 Augusta
College Station, Texas 77845
(979) 693-7830
Prepared By:
TEXCON General Contractors
1707 Graham Road
College Station, Texas 77845
(979) 690-7711
REV1E\/VED FOR
cn~,,101 ! f\ :\ICE
JUL 3 0 2001
COLLEl:;h:: v {A I 1Ul'1
ENGINEERING /1
CERTIFICATION
I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Texas, certify that this
report for the drainage design for the Castlegate Subdivision, Section 3, Phase 2 was prepared
by me in accordance with the provisions of the City of College Station Drainage Policy and
Design Standards for the owners hereof.
_,,,,,,,
--'\€. OF l' \\ ;'"'-.'Ir'-••••••••••• t::-r: ,, , 0 •• •• -</.(\ •• """' • • v· ,,. • • a , * .. •• * , .. ~k: ... ~ ~··································~ ~ ... ~Qgr.~ .. ~~ .. ~9.~.YH~ ... J l~.. 6 IC:--,_ ..,,~··.-9~ 5889 Qllt}
f ~···.<;'I S TE~~···~.-.
' Ss •••••••• ...,.~ *' \ 10 NAL ~--,~.,
I ~ i 1--fJ'
REVIEWED FOR
. CO~llDI II). JCE
JU L 3 0 2001
COLLEGE s -1 A flOl\J
ENGINEERING
TABLE OF CONTENTS
DRAINAGE REPORT
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
CERTIFICATION .................................................................................................................................................................. 1
TABLE OF CONTENTS ........................................................................................................................................................ 2
LIST OF TABLES .................................................................................................................................................................. 3
INTRODUCTION ................................................................................................................................................................... 4
GENERAL LOCATION AND DESCRIPTION ................................................................................................................. .4
FLOOD HAZARD INFORMATION .................................................................................................................................... 4
DEVELOPMENT DRAINAGE PATTERNS ....................................................................................................................... 4
DRAINAGE DESIGN CRITERIA ........................................................................................................................................ 5
STORM WATER RUNOFF DETERMINATION ............................................................................................................... 5
DETENTION FACILITY DESIGN ...................................................................................................................................... 7
STORM SEWER DESIGN .................................................................................................................................................... 7
CONCLUSIONS ..................................................................................................................................................................... 8
APPENDIX A .......................................................................................................................................................................... 9
Storm Sewer llllet Desigll Calculatiolls
APPENDIX B ........................................................................................................................................................................ 11
Storm Sewer Pipe Desigll Calculatiolls
APPENDIX C ........................................................................................................................................................................ 30
Draillage Chall/lei Nos. 4A & 4 Calculatiolls
EXHIBIT A ............................................................................................................................................................................ 34
Of/site lllfrastructure Plall for Castlegate Subdivisioll
EXHIBIT B ............................................................................................................................................................................ 36
Post-Developmellt Draillage Area Map
2
LIST OF TABLES
TABLE 1 -Rainfall Intensity & Time of Concentration Calculations .............................................. 6
TABLE 2 -Post-Development Runoff Information ............................................................................ 6
3
DRAINAGE REPORT
CASTLEGATE SUBDIVISION
SECTION 3, PHASE 2
INTRODUCTION
The purpose of this report is to provide the hydrological effects of the construction of the
Castlegate Subdivision, Section 3, Phase 2, and to verify that the proposed storm drainage
system meets the requirements set forth by the City of College Station Drainage Policy and
Design Standards.
GENERAL LOCATION AND DESCRIPTION
The project is located on a 162 acre tract located west of State Highway 6 along the north side
of Greens Prairie Road in College Station, Texas. This report addresses Section 3, Phase 2 of
this subdivision, which consists of 15 .20 acres. The site is wooded with the vegetation
primarily consisting of oak trees and yaupons. The existing ground elevations range from
elevation 291 to elevation 314. The general location of the project site is shown on the vicinity
map in Exhibit B.
FLOOD HAZARD INFORMATION
The project site is located in the Spring Creek branch of the Lick Creek Drainage Basin. The
site is located in a Zone X Area according to the Flood Insurance Rate Map prepared by the
Federal Emergency Management Agency (FEMA) for Brazos County, Texas and incorporated
areas dated July 2, 1992, panel number 48041C0205-C. Zone X Areas are determined to be
outside of the 500-year floodplain. However, LJA Engineering & Surveying, Inc. submitted a
Request for Conditional Letter of Map Revision (CLOMR) to FEMA to outline a proposed
100-year floodplain area. This CLOMR No. 00-06-844R was approved by FEMA on 9/8/2000.
The proposed floodplain area affects the western and northwestern edges of Section 3, Phase 2.
Refer to Exhibit B for the location of the 100-year floodplain area.
DEVELOPMENT DRAINAGE PATTERNS
The storm water runoff from the site prior to development flows in one general direction. For
Section 3, Phase 2, the acreage flows toward the west-northwest boundary of the tract and into
existing drainage channels and Spring Creek and ultimately flows north to the proposed
regional detention facility. Refer to the Offsite Infrastructure Plan in Exhibit A for the location
of this proposed detention facility.
4
DRAINAGE DESIGN CRITERIA
The design parameters for the storm sewer are as follows:
• The Rational Method is utilized to determine peak storm water runoff rates for the storm
sewer design.
• Design Storm Frequency
Storm Sewer system
• Runoff Coefficients
Pre-development
10 and 100-year storm events
Post-development (single family residential)
c = 0.30
c = 0.55
• Rainfall Intensity values for Brazos County for a minimum time of concentration of 10
minutes can be found in Table 1. Where a longer time of concentration was necessary, it is
noted in the respective table, and the intensities are calculated with the higher values where
required.
• Time of Concentration, tc -Due to the small sizes of the drainage areas, the calculated
times of concentration, tc, are less than 10 minutes. Therefore, a minimum tc of 10 minutes
is used in most cases to determine the rainfall intensity values. Where a longer time of
concentration was necessary, it is noted and used accordingly. Refer to Table 1 for
calculations.
STORM WATER RUNOFF DETERMINATION
The peak runoff values were determined in accordance with the criteria presented in the
previous section for the 5, 10, 25, 50, and 100-year storm events. The runoff coefficients are
based on the future development of this tract. Also, a majority of Section 4 drains into Section
3, so the Section 4 runoff is taken into consideration during analysis of the storm water runoff.
The drainage areas for post-development are shown in Exhibit B. Post-development runoff
conditions are summarized in Table 2.
5
TABLE 1 -Rainfall Intensity & Time of Concentration Calculations
The Rational Method:
Q =CIA
Q =Flow (cfs)
A= Area (acres)
C = Runoff Coeff.
I = Rainfall Intensity (in/hr)
Rainfall Intensity Values (in/hr)
Storm tc =
Event 10 min
l5 7.693
110 8.635
125 9.861
150 11 .148
1100 11 .639
Brazos County:
I = b I (tc+d)°
I = Rainfall Intensity (in/hr)
t0 = L/(V*60)
t0 =Time of concentration (min)
L = Length (ft)
V =Velocity (tusec)
5 1-:ear storm 10 1-:ear storm 25 1-:ear storm 50 1-:ear storm 100 1-:ear storm
b = 76 b = 80 b = 89 b = 98 b = 96
d = 8.5 d = 8.5 d = 8.5 d = 8.5 d = 8.0
e = 0.785 e = 0.763 e = 0.754 e = 0.745 e = 0.730
(Data taken from State Department of Hiqhwa1-:s and Public Transportation H1-:draulic Manual , page 2-16)
TABLE 2-Post-Development Runoff Information
A c tc Os 010 02s Oso 0100 Area#
(acres) (min) (cfs) (cfs) (cfs) (cfs) (cfs)
89 0.80 0.55 10 3.38 3.80 4.34 4.91 5.12
90 1.32 0.55 10 5.59 6.27 7.16 8.09 8.45
91 1.50 0.55 10 6.35 7.12 8.14 9.20 9.60
92 1.62 0.55 10 6.85 7.69 8.79 9.93 10.37
93 1.50 0.55 10 6.35 7.12 8.14 9.20 9.60
94 1.50 0.55 10 6.35 7.12 8.14 9.20 9.60
95 1.34 0.55 10 5.67 6.36 7.27 8.22 8.58
96 1.82 0.55 10 7.70 8.64 9.87 11.16 11 .65
97 1.96 0.55 10 8.29 9.31 10.63 12.02 12.55
98 0.48 0.55 10 2.03 2.28 2.60 2.94 3.07
98A 0.29 0.55 10 1.23 1.38 1.57 1.78 1.86
99 0.84 0.55 10 3.55 3.99 4.56 5.15 5.38
100 0.41 0.55 10 1.73 1.95 2.22 2.51 2.62
101 1.24 0.55 10 5.25 5.89 6.73 7.60 7.94
102 1.28 0.55 10 5.42 6.08 6.94 7.85 8.19
103 1.59 0.55 10 6.73 7.55 8.62 9.75 10.18
104 0.91 0.55 10 3.85 4.32 4.94 5.58 5.83
105 1.36 0.55 10 5.75 6.46 7.38 8.34 8.71
106 1.65 0.55 10 6.98 7.84 8.95 10.12 10.56
107 1.84 0.55 10 7.79 8.74 9.98 11.28 11 .78
6
DETENTION FACILITY DESIGN
The detention facility handling the runoff from this site will be a regional facility designed by
LJA Engineering & Surveying, Inc. Refer to the Offsite Infrastructure Plan in Exhibit A for the
location of this proposed detention facility. The runoff from this project flows into existing
drainages and then into Spring Creek. The detention facility is located adjacent to Spring
Creek prior to Spring Creek entering the State Highway 6 right-of-way.
STORM SEWER DESIGN
The storm sewer piping for this project has been selected to be Reinforced Concrete Pipe
(RCP) meeting the requirements of ASTM C-76, Class III pipe. The curb inlets and junction
boxes will be cast-in-place concrete.
Appendix A presents a summary of the storm sewer inlet design parameters and calculations.
Since the storm sewer design of Section 4 and Section 3, Phase 1 directly affects the design of
Section 3, Phase 2, these previously calculated runoff values are included. For Section 4
information specifically, refer to the drainage reports for Section 4, Phases 1 & 2, dated
November 2000 & January 2001, respectively. For Section 3, Phase 1 information, refer to the
drainage report dated December 2000. The inlets were designed based on a 10-year design
storm. As per College Station guidelines, the capacities of inlets in sump were reduced by 10%
to allow for clogging.
Inlets were located to maintain a gutter flow depth of 5" or less, which will prevent the spread
of water from reaching the crown of the road for the 10-year storm event. The runoff
intercepted by the proposed storm sewer inlets was calculated using the following equations.
The depth of flow in the gutter was determined by using the Straight Crown Flow equation.
The flow intercepted by Inlets 307, 308 & 309 was calculated by using the Capacity of Inlets
On Grade equation. The capacities for the inlets in sumps (Inlets 310-314) were calculated
using the Inlets in Sumps, Weir Flow equation with a maximum allowable depth of 7" (5"
gutter flow plus 2" gutter depression). These equations and the resulting data are summarized
in Appendix A.
Appendix B presents a summary of the storm sewer pipe design parameters and calculations.
All pipes are 18" in diameter or larger. For pipes with 18" and 24" diameters, the cross-
sectional area is reduced by 25%, as per College Station requirements. A summary of how this
was achieved is shown in Appendix B as well. The pipes for the storm sewer system were
designed based on the 10-year storm event; however, all but Pipe 313 will also pass the 100-
year storm event without any headwater. A drainage channel (Channel No. 4A) is proposed to
take the overflow from Pipe 313 into Channel No. 4, which drains into the existing creek.
More information on these channels is given later in this paragraph. As required by College
Station, the velocity of flow in the storm sewer pipe system is not lower than 2.5 feet per
second, and it does not exceed 15 feet per second. As the data shows, even during low flow
conditions, the velocity in the pipes will exceed 2.5 feet per second and prevent sediment build-
up in the pipes. The maximum flow in the storm sewer pipe system will occur in Pipe No. 313.
Appendix B contains a summary of the Manning pipe calculations as well as flow diagrams
mapping the flows through the storm sewer system for the 10 and 100-year events. The
maximum velocity for the pipe system in Section 3, Phase 2 will be 14.7 feet per second and
will occur in Pipe 312. The velocity in Channel No. 4A is 4.4 feet per second for the 100-year
7
event. This velocity is within the requirements for a seeded grass channel outlined on page 60
of the City of College Station Drainage Policy & Design Standards manual. The velocity in
Channel No. 4 is 5.5 feet per second for the 100-year event. As per the channel requirements
for the City of College Station, this channel will be lined with Bermuda grass sod. Rock riprap
will be placed at the beginning of Channel No. 4 at the end of the headwall attached to Pipe 313
to prevent erosion from the flow exiting this pipe. Refer to Appendix C for details on Channels
4A&4.
CONCLUSIONS
The construction of this project will significantly increase the storm water runoff from this site.
The proposed storm sewer system should adequately control the runoff and release it into
existing drainages. Also, the regional detention facility should adequately reduce the peak
post-development runoff to less than the pre-development runoff for the design storm event.
This will prevent any impact on the properties downstream of this project.
8
APPENDIX A
Storm Sewer Inlet Design Calculations
9
Castlegate Subdivision
Section 3 -Phases 2
Inlet Length Calculations
Inlets In Sump 10 year storm
Inlet# Length & Type Flow from A c o,. O,,ny~w QTotal Orot.1•1o'JI. Y10..aua1
Area# (acres) (els) (els) from 1ni.t# (els) (els) (ft)
Section 3/Phase 1 ·PREVIOUSLY SUBMITTED FOR REVIEW; INCLUDED FOR INFORMATIONAL PURPOSES ONLY
301 15' Recessed 3 1.73 0.55 8.22 0.00 8.22 9.04 0.341
87 1.78 0.55 8.45 8.45 9.30 0.344
Section 3/Phase 2
310 1 O' Recessed 91 1.5 0.55 7.12 0.00 308 7.12 7.84 0.323
99 0.84 0.55 3.99 3.99 4.39 0.260
311 1 O' Recessed 98A 0.29 0.55 1.38 0.72 309 2.09 2.30 0.204
97 1.96 0.55 9.31 9.31 10.24 0.357
312 1 O' Recessed 96 1.82 0.55 8.64 8.64 9.51 0.347
98 0.48 0.55 2.28 2.28 2.51 0.211
313 15' Recessed 103 1.59 0.55 7.55 0.00 315 7.55 8.31 0.330 1--102 1.28 0.55 6.08 6.08 6.69 0.304
314 10' Recessed 101 1.24 0.55 5.89 0.43 316 6.32 6.95 0.309
100 0.41 0.55 1.95 1.95 2.14 0.199
Inlets On Grade 10 year storm
FlowfTom y,, a,.,,_. Oc.pKlty QbypllH 0..,.",..1 Oc•nyov..-Inlet# Length & Type
Area# I (ft) I (In) (ft) (els) (els) (els) I (els) I from 1ni.t#
Section 3/Phase 1 • PREVIOUSLY SUBMITTED FOR REVIEW; INCLUDED FOR INFORMATIONAL PURPOSES ONLY
302 10' Recessed 4 0.310 3.71 0.60 6.04
303 1CJRecessed 88 0.270 3.24 0.57 5.66
304 10' Recessed 93 0.403 4.84 0.69 6.92
305 10' Recessed 95 0.383 4.60 0.68 6.76
306 10' Recessed 94 0.399 4.79 0.69 6.92
315 10' Recessed 104 0.332 3.98 ---o:63 6:25
316 10' Recessed 105 0.402 4.83 0.68 6.79
317 10' Recessed 106 D.4i5 ~ 0.71 7.08
318 15' Recessed 107 0.342 4.10 0.63 9.52
Section 3/Phase 2
307
308
309
10' Recessed 89 0.289 3.46 0.57 5.73
10' Recessed 90 0.305 3.66 0.60 6.00
10' Recessed 92 0.405 4.86 0.70 6.98
Transverse (Crown) slope (tuft)= 0.038
Straight Crown Flow !Solved to find actual depth of flow, y):
Q = 0.56' (z/n) 'S112 • y113 «> y ={QI [0.56' (z/n) 'S112]}318
n =Roughness Coefficient= 0.018
z = Reciprocal of crown slope = 26
S = StreeUGutter Slope (fUft)
y = Depth of now at inlet (ft)
Capacity of Inlets on grade:
Qc = 0.7 '[1/(H1 • H2)] '[H1~2-H,~2]
Q0 = Flow capacity of inlet (cfs)
H1 =a+ y
H2 =a =gutter depression (2" Standard; 4" Recessed)
y = Depth of flow in approach gutter (ft)
-1.71 4.32 0.00
-2.67 2.99 0.00
0.21 6.92 0.21 306
-0.35 6.41 0.00
0.21 6.92 0.00
-1 .93 4.32 0.00
-0.33 6.46 0.76 317, 318
0.76 7.08 0.00
-0.78 8.74 0.00
-1 .93 3.80 0.41 303,304,305
-1 .10 4.89 0.00 302
0.72 6.98 0.00 307
(In)
4.09
4.13
3.88
3:12
2.45
4.28
4.17
2.53
3.96
'J.65
3.70
2.38
Qbyp-lot ..
(els)
0.00
0.00
0.41
0.00
0.21
0.00
0.43
0.76
0.00
0.00
0.00
0.72
100 year storm
L10~,.q·d· L10..ctu•I o,,. O,,ny~w Orot•I Orotal+1D'll. y,,.
(ft) (ft) (els) (els)
13.73 15 11.07 0.00
11.39
9.60 0.25 9.15 10 '5:38 ---
9.39 10 1.86 7.79
12.55
9.00 10 11.65
3.07
11.23 15 10.18 0.00
8.19
6.81 10 7.94 6.08
2.62
\1Pig r-• r • o.583'
Cc.p1-1otl Q10·Tot.I y,,.
(els) (els) (ft) (In)
4.32 4.32 0.346 4.15
2.99 2.99 0.302 3.62
6.92 7.33 0.482 5.78
6.41 6.41 0.429 5.14
6.92 7.12 0.446 5.35 '---o2 4.32 0.371 ·--us
6.79 7.21 Q.506 ·~
7.08 7.84 0.464 5.57
8.74 8.74 0.382 4.59
4.21 4.21 0.413 4.95
4.89 4.89 0.341 4.10
6.98 7.69 0.523 6.28
Inlets In sumps, Weir Flow:
L = Q I (3 ' y31') «> y = (Q I 3L)213
L = Length of inlet opening (ft)
Q =Flow at inlet (els)
y =total depth of now on inlet (ft)
max y for inlet in sump= 7" = 0.583'
from inlet# (els) (els) (ft)
11.07 12.18 0.671 """'11.39 12.53
308 9.85 10.83 0.678 -5.38 5.91
309 9.65 10.61 0.872
12.55 13.80
11.65 12.82 0.663 3.07 3.38
315 10.18 11.20 0.586 8.19 9.01
316 14.02 15.42 0.719
2.62 2.89
100 year storm
o,... .... Oc•PKlty Co,,... Oc•pturM
(ft) (els) (els) (els)
0.64 6.39 -0.57 5.83
0.60 5.96 -1.93 4.03
0.74 7.40 2.20 7.40
0.72 7.22 1.42 7.22
0.74 7.40 2.20 7.40
0.66 6.64 -0.82 5.83
0.73 7.25 1.45 7.25
0.76 7.59 2.97 7.59
0.68 10.13 1.65 10.13
0.60 6.05 -0.93 5.12 ---0.63 6.35 0.25 6.35 ---0.75 7.47 2.90 7.47
(In)
8.05
8.14
10.46
7.96
7.04
8.63
O,,ny~w 0.,.p-lot•I Ccapl-totl 0100-Total s L,.....,
(els) from Inlet# (els) (els) (els) (ft/ft) (ft)
0.00 0.00 5.83 5.83 0.0145 10
0.00 0.00 4.03 4.03 0.0145 10
2.20 306 4.40 7.40 11.80 0.0102 10
0.00 1.42 7.22 8.64 0.0102 10
0.00 2.20 7.40 9.60 0.0102 10
0.00 0.00 5.83 5.83 0.0100 10
4.63 317, 318 6.08 7.25 13.33 0.0100 10
0.00 2.97 7.59 10.56 0.0100 10
0.00 1.85 10.13 11.78 0.0350 15
5.82 303,304,305 4.89 6.05 10.94 0.0200 10
0.00 302 0.25 6.35 6.59 0.0200 10
4.89 307 7.79 7.47 15.26 0.0110 10
APPENDIXB
Storm Sewer Pipe Design Calculations
11
I
I
I
~
I
I
Castlegate Subdivision
Section 3, Phase 2
Size Inlet Pipe# Length Slope Invert Elev
(in) (ft) (%) (ft)
308A 54 85.0 1.30 303.38
310 60 134.0 1.10 301.41
311 60 174.1 1.10 299.84 ---312 60 125.0 1.10 297.71
313 60 180.0 0.95 296.24
309 18 28.1 0.96 305.27
321 27 201.6 1.00 304.42
320 27 141 .2 1.00 302.36
318 36 224.6 0.98 300.16
317 42 161 .6 0.43 297.57
314 48 39.9 1.10 296.78
319 27 28.3 1.43 301 .56
316 27 28.0 0.54 298.74
315 30 69.1 0.84 298.36
Outlet
Invert Elev •Actual FIO¥ Design Flow
(ft) (cfs) (cfs)
302.28 153.41
299.94 162.51
297.92 162.51
296.34 169.49
294.53 251.42
305.00 4.89 7.90
302.40 26.60
300.95 26.60
297.96 48.50
296.88 48.50
296.34 70.82
301 .16 8.27
298.59 11.40
297.78 22.32
10 year storm 100 year storm
!>Actual FIO¥ V100 Travel Time, tr1oo V10 Travel Time, h11 Design Flow %Full %Full
(fps) (sec) (min) (cfs) (cfs) (fps) (sec) (min)
14.3 63.8 6 0.10 214.14 14.9 84.8 6 0.10
13.7 58.2 10 0.16 226.54 14.6 73.7 9 0.15
13.7 58.2 13 0.21 226.54 14.6 73.7 12 0.20
13.8 59.8 9 0.15 234.01 14.7 75.8 9 0.14
13.5 90.2 13 0.22 351.97 13.2 100.0 14 0.23
---------6.0 69.3 5 0.08 6.35 10.26 6.0 92.1 5 0.08
8.2 75.9 25 0.41 30.80 8.1 91 .2 25 0.41
8.2 75.9 17 0.29 30.80 8.1 91 .2 17 0.29
9.6 67.1 23 0.39 65.81 9.7 92.0 23 0.39 ---7.1 67.1 23 0.38 65.81 7.1 92.4 23 0.38 ---11 .2 50.4 4 0.06 102.73 12.2 63.7 3 0.05
~ ------7.1 33.4 4 0.07 16.64 8.6 49.0 3 0.05
5.4 52.3 5 0.09 22.20 6.0 87.5 5 0.08
7.5 58.1 9 0.15 36.92 8.0 88.5 9 0.14
City of College Station requirement to Reduce Cross-Sectional Area of 18" & 24" Pipes by 25%
Using Mannings Equation from page 48 of the College Station Drainage Policy & Design Standards Manual:
Q = 1.49/n *A* R213 * S112
Q =Flow Capacity (cfs)
18" Pipe:
Pipe size (inches)= 18
Wetted Perimeter WP, (ft)= 4.71
Cross-Sectional Area A, (ff) = 1. 766
Reduced Area AR, (ft2) = 1.325
Hydraulic Radius R =A/WP, (ft)= 0.375
Reduced Hydr Radius RR= AR/Wp, (ft)= 0.281
Roughness Coefficient n = 0.014
Friction Slope of Conduit Sr. (ft/ft) = 0.01
Example Calculation:
Slope Flow Capacity Reduced Flow Capacity % Difference
s Q Oreduced Oreduced/Q
0.005 6.91 4.28 0.619
0.006 7.57 4.69 0.619
0.007 8.18 5.06 0.619
24" Pipe:
Pipe size (inches) = 24
Wetted Perimeter WP, (ft)= 6.28
Cross-Sectional Area A, (ff) = 3.14
Reduced Area AR, (ff)= 2.355
Hydraulic Radius R =A/WP, (ft)= 0.5
Reduced Hydr Radius RR= AR/Wp, (ft)= 0.375
Roughness Coefficient n = 0.014
Friction Slope of Conduit Sr. (ft/ft) = 0.01
Example Calculation:
Slope Flow Capacity Reduced Flow Capacity % Difference
s Q Oreduced Oreduced/Q
0.005 14.89 9.22 0.619
0.006 16.31 10.1 0.619
0.007 17.61 10.9 0.619
Conclusion:
Multiply actual Q in 18" & 24" pipes by 1.615 to reflect a 25% reduction in the
cross-sectional area called for on page 47, paragraph 5 of the College Station
Drainage Policy & Design Standards manual.
(From Phase 1)
June Box 303A
J,
Pipe 308A I 153 .41
J,
Inlet 3071 4.21
J,
Pipe 3101 162.51
J,
June Box 303
J,
Pipe311l 162.51
J,
Inlet 3091 6.98
J,
Pipe 3121 169.49
J,
lnlet310I 11 .11 ~
J,
llPipe 3131 251 .42 II
Castlegate Subdivision
Section 3, Phase 2 -Pipe Flow Diagram
010 (cfs)
Inlet 314 1 8.27
J,
Inlet 3081 4.89 Pipe 3191 8.27
J, J,
Pipe 3091 4.89 lnlet311 l 11.40
J,
Pipe 3161 11.40 Inlet 313 1 13.63
J, J,
Inlet 312 1 10.92 Pipe 3181 48.50
J, J,
Pipe 3151 22.32 June Box 305
J, J,
J, Pipe 3171 48.50
J, ~
June Box 304
J,
~ ~ ~ ~ Pipe 3141 70 .82
(From Phase 1)
Pipe 321 I 26.60
J,
June Box 306
Pipe 3201 26.60
(From Phase 1)
June Box 303A
J,
Pipe 308AI 214 .14
J,
Inlet 3071 6.05
J,
Pipe 3101 226 .54
J,
June Box 303
J,
Pipe311 l 226.54
J,
Inlet 3091 7.47
J,
Pipe 3121 234.01
J,
Inlet 3101 15.23
J,
llPipe 3131 351.97 II
Castlegate Subdivision
Section 3, Phase 2 -Pipe Flow Diagram
Q100 (cfs)
Inlet 308 1 6.35
J,
Pipe 3091 6.35 Inlet 311 I 22.20
J,
Pipe 3161 22.20
J,
Inlet 312 1 14.72
J,
Pipe 3151 36.92
June Box 304
~ ~ ~ ~ ~ Pipe 3141 102.73
Inlet 3141 16.64
J,
Pipe 3191 16.64
J,
J,
J,
Inlet 313 1 18.37
J,
Pipe 3181 65.81
J,
June Box 305
J,
Pipe 3171 65.81
(From Phase 1)
Pipe 321 I 30.80
J,
June Box 306
Pipe 3201 30.80
Pipe 308A -10 Year Storm
Manning Pipe Calculator
Giv en Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ....................... · · · · ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of.Flow/
54 .0000 in v' /"
153. 4100 cfs ~
0. 0130 ft/ft
0. 0140
34.4673 in
15 .9043 ft2
10 .7163 ft2
99.9549 in
169 .6460 in
14.3156 fps
15 .4384 in ./
63 .8283 %
208 .1992 cfs
13 .0907 fps
Pipe 308A -100 Year Storm
Manning Pipe Calculator
Given Input Data :
Shape .......................... .
Solv ing for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Resul ts:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Rad ius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
54.0000 in
214.1400 cfs
0. 0130 ft/ft
0 . 0140
45.7870 in
15.9043 ft2
14.3780 ft2
126.3789 in
169.6460 in
14.8936 fps
16 .3827 in /
84.7907 %
208.1992 cfs
13 .0907 fps
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
Pipe 309 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results:
Depth .......................... .
Area ................... · ·. · · · · · ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
18.0000 in
7.9000 cfs
0. 0096 ft/ft ,,,.
0.0140
12.4784 in
1 .7671 ft2
1 .3073 ft2
35.4172 in
56.5487 in
6.0430 fps
5.3152 in
69.3246 %
9.5570 cfs
5.4081 fps
Pipe 309 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
18.0000 in
10.2600 cfs
0.0096 ft/ft
0. 0140
16.5806 in
1.7671 ft2
1.7023 ft2
46.3017 in
56.5487 in
6 .0271 fps
5.2943 in
92.1145 %
9 .5570 cfs
5.4081 fps
Castlegate Subdiv ision, Section 3 , Phase 2
College Station, Texas
Pipe 310 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Circular
Depth of Flow
60.0000 in
162 .5100 cfs
0 .0110 ft/ft
Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0140
Computed Results:
Depth ........................... 34.9129 in
Area ............................ ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
19.6350 ft2
11. 8553 ft2
104. 1180 in
188.4956 in
13. 7078 fps /
16.3965 in
58.1882 % ./
253.6435 cfs
12.9180 fps
Pipe 310 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
60.0000 in
226.5400 cfs
0 . 0110 ft/ft
0. 0140
44.2170 in
19.6350 ft2
15.5113 ft2
123 .8706 in
188.4956 in
14 .6048 fps
18 .0320 in
73 .6949 %
253.6435 cfs
12.9180 fps
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
Pipe 311 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circul ar
Depth of Flow
60.0000 in
162.5100 cfs
O.OllO ft/ft
0. 0140
34.9129 in
19.6350 ft2
ll.8553 ft2
104. ll80 in
188.4956 in
13.7078 fps
16.3965 in "'
58. 1882 % ,,,
253.6435 cfs
12 .9180 fps
Pipe 311 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Circular
Depth of Flow
60 .0000 in
226.5400 cfs
O.OllO ft/ft
0 .0140
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 . 2170 in
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
19.6350 ft2
15.5113 ft2
123.8706 in
188.4956 in
14.6048 fps
18. 0320 in /
73 .6949 %
253.6435 cfs
12.9180 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 312 -10 Year Storm
Manni ng Pipe Calculator
Given Input Data:
Shape .......................... .
Solv ing for .................... .
Diameter ....................... .
Flowrat e ....................... .
Slope .......................... .
Manning's n .................... .
Computed Result s:
Circular
Depth of Flow
60 .0000 in ./
169.4 900 cfs /
0 . OllO ft/ft,/
0 . 0140
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 . 873 4 i n
Ar ea ........................... .
We tted Ar ea .................... .
Wetted Per imeter ............... .
Per imeter ...................... .
Ve l ocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Fl owrate ............. .
Full flow v elocity ............. .
19 .6350 ft2
1 2 .2 490 ft2
106 .0709 in
188 .4956 in
13 . 8371 fps
16 .6290 in
59.7889 %
253.6435 cfs
12 .9180 fps
Pipe 312 -100 Year Stor m
Manni ng Pipe Calculator
Giv en Input Data :
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results :
Depth .......................... .
Ar ea ........................... .
Wetted Area .................... .
Wetted Per imeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
60.0000 in
2 34 .0100 cfs
0 . OllO ft/ft
0 . 0140
45 .4597 in
19 .6350 ft2
15.961 3 ft 2
126 .7309 in
188 .4956 in
14 .6611 fps
18 .1363 in /
75.7662 %
253 .6435 cfs
12 .9180 fps
Castlegate Subdiv ision, Section 3 , Phase 2
College Station, Tex as
Given Input Data:
Pipe 313 -10 Year Storm
Manning Pipe Calculator
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Circular
Depth of Flow
60.0000 in
251 .4200 cfs
0. 0095 ft/ft ~
0.0140
Computed Results:
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 54. 1043 in
Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19. 6350 ft2
Wetted Area . . . . . . . . . . . . . . . . . . . . . 18.6391 ft2
Wetted Perimeter ................ 150.2346 in
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
188.4956 in
13.4889 fps
17.8655 in
90.1739 %
235 .7160 cfs
12.0049 fps
Pipe 313 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
/
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Circular
Depth of Flow
60.0000 in
253 .5600 cfs
0.0095 ft/ft
0. 0140
Computed Results:
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 56. 2430 in
Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19. 6350 ft2
Wetted Area ..................... 19.1226 ft2
Wetted Perimeter . . . . . . . . . . . . . . . . 158 .1452 in
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
188.4956 in
13.2597 fps
17.4122 in
93.7384 %
235.7160 cfs
12.0049 fps
Castlegate Subdivision, Section 3 , Phase 2
College Station, Texas
Pipe 314 -10 Year Storm
Manni ng Pipe Calculator
Given Input Data :
Shape .......................... .
Solv ing for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
48. 0000 in /
70.8200 cfs
0.0110 ft/ft
0 . 0140
24.1763 in
12.5664 ft2
6.3420 ft2
75 .7509 in
150.7964 in
11. 1669 fps
12.0559 in
50.3674 % /
139.8933 cfs
11.1324 fps
Pipe 314 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
48.0000 in
102.7300 cfs
0.0110 ft/ft
0.0140
30 .5662 in
12.5664 ft2
8.4443 ft2
88.7002 in
150.7964 in
12.1656 fps
13.7089 in /
63.6796 %
139.8933 cfs
11.1324 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 315 -10 Year Storm ~
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results :
Depth .......................... .
Ar ea ..................... · · · · · · ·
Wetted Ar ea .................... .
Wetted Per imeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
30 .0000 in
22.3200 cfs
0 .0084 ft/ft
0.0140
17.4338 in
4 .9087 ft2
2.9592 ft2
52.0131 in
94 .2478 in
7.5426 fps
8.1926 in
58.1127 %
34.9076 cfs
7. 1113 fps
Pipe 315 -100 Year Storm
Manning Pipe Calculator
Given Input Data :
Shape .......................... .
Solv ing for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Ar ea .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
30 .0000 in
36 .9200 cfs
0.0084 ft/ft
0. 0140
26.5598 in
4.9087 ft2
4.5965 ft2
73.5200 in
94.2478 in
8.0322 fps
9.0030 in
88 .5328 %
34 .9076 cfs
7. 1113 fps
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
Pipe 316 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................ · · · ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Ve locity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
11 .4000 cfs
0.0054 ft /ft
0 . 0140
14.1240 in
3.9761 ft2
2.1050 ft2
43.6599 in
84.8230 in
5 .4157 fps
6.9427 in
52 .3111 %
21 .1328 cfs
5.3150 fps
-
Pipe 316 -100 Year Storm
Manni ng Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wett ed Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
22.2000 cfs
0 .0054 ft/ft
0. 0140
23 .6162 in
3.9761 ft2
3.6881 ft2
65.2826 in
84.8230 in
6.0193 fps
8 .1352 in
87.4674 %
21.1328 cfs
5.3150 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 317 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
42 .0000 in ,/
48.5000 cfs
0.0043 ft/ft
0. 0140
28 . 2011 in
9. 6211 ft2
6.8690 ft2
80.6739 in
131.9469 in
7 .0608 fps
12.2608 in
67.1454 %
61.2618 cfs
6.3674 fps
Pipe 317 -100 Year Storm
Manning Pipe Calculator
Giv en Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results :
Depth .......................... .
Area ........................... .
Wetted Ar ea .................... .
Wetted Peri meter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full f l ow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
42.0000 in
65.8100 cfs
0.0043 ft/ft
0. 0140
38 .8161 in
9 . 6211 ft2
9 .2881 ft2
108 .5163 in
131.9469 in
7 .0854 fps
12.3252 in ,,.,,.,...,.
92.4192 %
61 .2618 cfs
6.3674 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 318 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manni ng's n .................... .
Computed Results :
Depth .......................... .
Area ........................ · · · ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
36 .0000 in
48 .5000 cfs
0 .0098 ft/ft
0.0140
24.1581 in
7.0686 ft2
5.0432 ft2
69. 1187 in
113 .0973 in
9.6169 fps
10.5069 in
67.1057 %
61.3117 cfs
8 .6738 fps
Pipe 318 -100 Ye ar Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results :
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
36.0000 in
65.8100 cfs
0.0098 ft/ft
0.0140
33.1326 in
7.0686 ft2
6.8054 ft2
92.4974 in
113.0973 in
9.6703 fps
10.5946 in
92.0350 %
61.3117 cfs
8.6738 fps
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
Pipe 319 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results :
Circular
Depth of Flow
27 .0000 in
8.2700 cfs
0 .0143 ft/ft
0. 0140
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 9. 0147 in
Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. 9761 ft2
Wetted Area . . . . . . . . . . . . . . . . . . . . . 1.1628 ft2
Wetted Perimeter ................ 33.2672 in
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
84.8230 in
7.1122 fps
5 .0333 in
33.3879 %
34.3897 cfs
8.6492 fps
-
Pipe 319 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................ · · · ·
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Circular
Depth of Flow
27 .0000 in
16.6400 cfs
0.0143 ft/ft
0. 0140
13.2427 in
3 .9761 ft2
1.9398 ft2
41.8969 in
84.8230 in
8.5782 fps
6 .6671 in
49.0471 %
34 .3897 cfs
8 .6492 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 320 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Comput ed Results:
Depth .......................... .
Area ........................ · · · ·
Wetted Area .................... .
Wetted Perimet er ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
26.6000 cfs
0.0100 ft/ft
0. 0140
20.5030 in
3.9761 ft2
3.2396 ft2
57.1368 in
84.8230 i n
8.2109 fps
8.1646 in
75.9372 %
28 .7581 cfs
7.2328 fps
Pipe 320 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
30.8000 cfs
0.0100 ft/ft
0.0140
24.6371 in
3.9761 ft2
3 .8060 ft2
68.6054 in
84.8230 in
8.0925 fps
7 .9886 in
91.2484 %
28 .7581 cfs
7.2328 fps
Castlegate Subdivision, Section 3, Phase 2
College Station, Texas
Pipe 321 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solv ing for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocit y ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
26.6000 cfs
0. 0100 ft/ft /
0. 0140
20.5030 in
3.9761 ft2
3.2396 ft2
57.1368 in
84.8230 in
8.2109 fps
8.1646 in
75.9372 %
28.7581 cfs
7 .2328 fps
Pipe 321 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocit y ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
30.8000 cfs
0 .0100 ft/ft
0.0140
24.6371 in
3.9761 ft2
3.8060 ft2
68.6054 in
84.8230 in
8 .0925 fps
7 .9886 in
91.2484 %
28.7581 cfs
7.2328 fps
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
APPENDIXC
Drainage Channel Nos. 4A & No. 4 Calculations
30
Castlegate Subdivision
Drainage Channel 4A Calculations -Section 3, Phase 2
Area
Flow into Pipe 313:
Max flow contained by Pipe 313:
Total Flow to Drainage Channel 4A:
The Rational Method:
Q=CIA
Q = Flow (cfs)
A= Area (acres)
C = Runoff Coeff.
I = Rainfall Intensity (in/hr}
•
a 10 a100
(cfs) (cfs)
251.42 351.97 I
253.56 253.56 \
/
/
0.00 98.41 v /
Drainage Channel No. 4A -10 Year Storm
Channel receives no flow for 10-year storm.
Drainage Channel No . 4A -100 Year Storm /'
Channel Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Height ......................... .
Bottom width ................... .
Left slope ..................... .
Right slope .................... .
Computed Results:
Depth .......................... .
Velocity ....................... .
Full Flowrate .................. .
Flow area ...................... .
Flow perimeter ................. .
Hydraulic radius ............... .
Top width ...................... .
Area ........................ · · ·.
Perimeter ...................... .
Percent full ................... .
Trapezoidal
Depth of Flow
98.4100 cfs
0.0095 ft/ft
0 .0350
24.0000 in
120.0000 in
0 .3300 ft/ft (V/H)
0.3300 ft/ft (V/H)
18.1333 in
4.4669 fps
167.2238 cfs
22.0307 ft2
235.7285 in
13. 4579 in
229.8991 in
32.1212 ft2
273.1699 in
75.5556 %
Castlegate Subdivision, Secti on 3 , Phase 2
College Station, Tex as
Drainage Channel No. 4 -10 Year Storm
Channel Calculator
Given Input Data :
Shape .......................... .
Solving for .................... .
Flowrat e ....................... .
Slope .......................... .
Manning ' s n .................... .
Height ......................... .
Bottom width ................... .
Left slope ..................... .
Right slope .................... .
Computed Results:
Depth .......................... .
Velocity ....................... .
Full Flowrate .................. .
Flow area ...................... .
Flow perimeter ................. .
Hydraulic radius ............... .
Top width ...................... .
Area ........................... .
Perimeter ...................... .
Percent full ................... .
Trapezoidal
Depth of Flow
251.4200 cfs
0.0060 ft/ft
0.0350
60 .0000 in
60.0000 in
0 .3300 ft/ft (V/H)
0.3300 ft/ft (V/H)
39.7233 in
5.0529 fps
647 .2272 cfs
49. 7572 ft2
313.5174 in
22.8537 in
300.7474 in
100.7576 ft2
442.9248 in
66.2055 %
Drainage Channel No. 4 -100 Year Storm
Channel Calculator
Given Input Data :
Shape .......................... .
Solving for .................... .
Flowrate ....................... .
Slope .......................... .
Manning ' s n .................... .
Height ......................... .
Bottom width ................... .
Left slope ..................... .
Right slope .................... .
Computed Results :
Depth .......................... .
Velocity ....................... .
Full Flowrate .................. .
Flow area ...................... .
Flow perimeter ................. .
Hydraulic radius ............... .
Top width ...................... .
Area ........................... .
Perimeter ...................... .
Percent full ................... .
Trapezoidal
Depth of Flow
351.9700 cfs
0.0060 ft/ft
0.0350
60 .0000 in
60 .0000 in
0.3300 ft/ft (V/H)
0 .3300 ft/ft (V/H)
46.1009 in
5 .5053 fps
647.2272 cfs
63.9328 ft2
354.2195 in
25.9905 in
339.3993 in
100 .7576 ft2
442.9248 in
76.8348 %
Castlegate Subdiv ision, Section 3, Phase 2
College Station, Texas
EXHIBIT A
Offsite Infrastructure Plan for Castlegate Subdivision
34
EXHIBIT B
Post-Development Drainage Area Map
36