HomeMy WebLinkAbout81 Development Permit 644 Nimitz Street TownhomesDEC-17-99 FRI 11:34 GALINDO ENGINEERS 4098468868 P.02
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846·8868 ·----------
EROSION PROTECTION PLAN
NIMITZ STREET CONDOMINIUMS
T-POST DRIVEN 2'
2-1/2" REINF. BAR
PER HAY BALE
SILT FENCING
NOT TO SCALE
8-99
THE CONTRACTOR SHALL BE RESPONSIBLE FOR SEDIMENTATION CONTROL
DURING CONSTRUCTION ANO SHALL TAKE THE NECESSARY STEPS TO
MITIGATE THE AMOUNT OF SOIL AND DEBRIS ORIGINATED AT THE SITE
AND CARRIED ONTO PUB.UC RIGHTS OF WAY, WATER COURSES AND
ADJACENT PROPERTY. TO THIS EFFECT THE CONTRACTOR SHALL INSTALL
A SILTING BARRIER ALONG THE LOWER ENDS OF THE LAND BEING ,
DISTURBED ACCORDING TO THE DETAIL SHOWN HEREON OR AN ,.,.-...'''""o'F\\\\\\u,.
EQUIVALENT ACCEPTABLE STRUCTURE . ~..,. "\ °t. T l"_i, ,.,
:-.I.. hr.. ·••·••••••..... 'lA f.
- . 'r .. * . -, l,
CHRISTIAN A . GALINDO, P.E. # 53425, R.P .L.S . # 4473
DEC . 1 7 I 1999
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iCHRISTIAN A. GALINOO)
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DEC-17-99 FRI 11:34 GALINDO ENGINEERS
'if'·
4098468868
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846·8868
FAX MEMO
"i "' GEP Project: .. Date: PE~. /7, / 99~
TO:
FROM:
SUBJECT:
RETURN FAX-# 409-846-8868
NUMBER OF PAGES:
COMMENTS:
Ct:,' #er<? /Zt?d H~Mt5
.t=AX 1!4.b-.ff"GO/
P.01
DEC-1 4 -99 TUE 1 7 :46 GALINDO ENGINEERS 4098468868 P.01
GALINDO ENGINEERS AND PLANNERS, fNC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846·8868
FAX MEMO
GEP Project: ~-'79 Date : ./JPC . 14-" /9.:;'?
TO :
FROM : cHfi:IS. <ijALINpO
SUBJECT :
RETURN FAX# 409-846-8868
NUMBER OF PAGES :
COMMENTS:
c----
DE C-1 4-99 TUE 17:47 GALINDO ENGI N EER S 4098468 8 68 P .0 2
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan , Texas 77802 (409 ) 846-8868
Mrs. Veronica Morgan, P.E.
Engineering Department
P. 0 . Box 9960
City of Coll&ge Station
Colled~ Station, TX 77842
April 16 1 1999
Subject: Drainage Report of March 11 , 1999
Nimitz Street Townhomes
College Station , TX
Dear Veron ica :
In response to your latest comment regarding the referenced report {and my
subsequent letter of April 8, 1999) I would like to indicate that the calculated increase
in the rate of storm water runoff caused by the project wHI not exceed the boundaries
of Cooner Street right of way, except at the end of the street where currently the
existing runoff traverses private property before reaching the primary system.
Sincerely,
GALINDO ENGINEERS AND PLANNERS, ]NC.·
,,-7 / tJ J/ ' j /\ (:??4,w_Z~ 'VJ~y
C°fl-rfstlan·A. Galindo, P.E. # 53425, R.P.L.S. # 4473
President
cc: Charles H . Szabuniewicz ,
Horizon Homes
DEC-16-99 THU 13:50 GALINDO ENGINEERS 4098468868
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 eryan, Texas 77802 (409) 846·8868
Mr. Jeff Tondree, P.E.
Engineering Department
P. 0 . Box 9960
City of College Station
College Station, TX 77842
Fax: 764-3496
December 16, 1999
Subject: Drainage Report of March 11, 1999
Nimitz Street Townhomes
College Station , TX
Dear Jeff:
P.01
Further to my letter of April 16, 1999 dealing with the referenced subject and as
discussed with you on the phone today I wish to add/modify the following sentence to
the contents of said letter:
The calculated increase in the rate of storm water runoff caused by the project will not
exceed the boundaries of Cooner Street right of way and will not adversely impact any
downstream properties along the route to the primary system (detention pond) located
at the rear of the Albertson Shopping Center.
Sincerely,
GALINDO ENGINEERS AND PLANNERS, INC.
~AiJg
Christian A. Galindo, P.E. # 53425, R.P.L.S. # 4473
President
cc: Charles H. Szabuniewicz,
Horizon Homes
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846-8868
Mrs. Veronica Morgan, P.E.
Engineering Department
April 6, 1999
City of College Station 0 ,,
College Station, TX ~ CJJ\\
Subject:
Dear Veronica:
In. response to the comment from your office noted on the face of the referenced
report I have performed the analysis given below.
Cooner Street, a dead-end local residential street, constitutes the drainage system
between the site and the Primary System of Burton Creek. The runoff after
development caused by the subject project increases from 2.1 O cfs to 3 .14 cfs for the
100-yr storm (see referenced report).
Exhibit 1 attached to this letter shows a portion of Cooner Street with contour lines
and spot elevations taken from the Site Plan/Grading Plan. It also shows a cross-
section of Cooner Street. Exhibit 2 shows the effect of the additional runoff on the
carrying capacity of Cooner Street. The runoff increase causes a corresponding
increase in the depth of water from 0.27' to 0.32'. this 0.05 ' vertical increase
corresponds to a horizontal expansion of 1.32 ' for the runoff sheet. Or looking at the
horizontal expansion of the runoff sheet, the width of water for the 100-yr storm goes
from 7.16 ' to 8.48' after development.
Sincerely,
GALINDO ENGINEERS AND PIANNERS, INC.
Christi an A. Galindo, P.E. # 53425, R.P.L.S. # 4473
President
cc: Charles H. Szabuniewicz,
Horizon Homes
'
/
• .. GALINDO ENGINEERS AND PLANNERS, INC.
CURB
rLL----------.-;;;;;;2~s.5::i,~1.o9..__J.Jl o.5·
337.2 x
27.5'
COONER STREET
/
+ 337.+
EXHIBIT 1
/
°Co
3
·/
GALINDOENGINEERSANDPLANNERS
Triangular Channel Analysis & Design
Ooen Channel -Uniform flow
Worksheet Name : NIMITZ ST . TOWNHOMES
Comment: Cooner Street, Q-100 Pre Dev.
Solve For Depth
Given lnout Data:
Left Side Slope ..
Right Side Slooe.
Manning's n ..... .
Channe I S 1 ooe ... .
Discharge ....... .
Comouted Results:
Deoth ........... .
Velocity ........ .
Flow Area ....... .
Flow Too Width .. .
Wetted Perimeter.
Critical Depth .. .
Critical Slope .. .
Froude Number ... .
26.50:1 (H:V)
0.00: 1 (H:V)
0.015
0.0071 ft/ft
2.10 cfs
0.27 ft
2.15 fos
0.98 sf
1. 19 ft
1. 47 ft
0.27 ft
0.0067 ft/ft
1.03 (flow is Supercritical)
EXHIBIT 2
Triangular Channel Analysis & Design
Open Channel -Uniform flow
Worksheet Name: NIMITZ ST. TOWNHOMES
Comment: Cooner Street , Q-100 Post Dev.
Solve For Depth
Given lnout Data :
Left Side Slope ..
Right Side Slooe .
Manning's n ..... .
Channel Slope, .. .
Discharge ....... .
Computed Results:
Deoth ........... .
Velocity ........ .
Flow Area ....... .
Flow Top Width .. .
Wetted Perimeter.
Critical Depth .. .
Critical Slope .. .
Froude Number ... .
26.50:1 (H:V)
0.00: 1 (H:V)
0.015
0.0071 ft/ft
3.14 cfs
0.32 ft
2.38 fos
1. 32 sf
8.37 ft
8.69 ft
0.32 ft
0.0063 ft/ft
1.05 (flow is Suoercritical)
Ooen Channel Flow Module. Version 3.21 (c) 1990
Haestad Methods. Inc. * 37 Brookside Rd* Waterbury, Ct 06708
•
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846-8868
Mrs. Veronica Morgan, P.E.
Engineering Department
City of College Station
College Station, TX
April 6, 1999
Subject: Drainage Report of March 11, 1999
Nimitz Street Townhomes
College Station, TX
Dear Veronica :
In response to the comment from your office noted on the face of the referenced
report I have performed the analysis given below.
Cooner Street, a dead-end local residential street, constitutes the drainage system
between the site and the Primary System of Burton Creek . The runoff after
development caused by the subject project increases from 2 .1 O cfs to 3.14 cfs for the
100-yr storm (see referenced report).
Exhibit 1 attached to this letter shows a portion of Cooner Street with contour lines
and spot elevations taken from the Site Plan/Grading Plan. It also shows a cross-
section of Cooner Street. Exhibit 2 shows the effect of the additional runoff on the
carrying capacity of Cooner Street. The runoff increase causes a corresponding
increase in the depth of water from 0.27' to 0 .32 '. this 0 .05' vertical increase
corresponds to a horizontal expansion of 1.32 ' for the runoff sheet. Or looking at the
horizontal expansion of the runoff sheet, the width of water for the 100-yr storm goes
from 7.16' to 8.48' after development.
Sincerely,
GALINDO ENGINEERS AND PLANNERS, INC.
Christian A. Galindo, P .E. # 53425, R.P .LS. # 4473
President
cc: Charles H. Szabuniewicz,
Horizon Homes
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GALINDO ENGINEERS AND PLANNERS, INC.
CURB
fll-----------_;2:;:s.s:i_, 1~.o~_J.Jl o.s·
337.2 x
27.5'
COONER STREET
'
/
+ 337.4
EXHIBIT 1
/
°Co
,. GALINDO ENGINEERS AND PLANNERS
Triangular Channel Analysis & Design
Ooen Channel -Uniform flow
Worksheet Name: NIMITZ ST. TOWNHOMES
Comment: Cooner Street, Q-100 Pre Dev.
Solve For Depth
Given Input Data:
Left Side Slope ..
Right Side Slope ,
Manning's n ..... .
Channel Slooe .. ..
Discharge ....... .
Comouted Results:
Deoth ........... .
Velocity ........ .
Flow Area ....... .
Flow Too Width .. .
Wetted Perimeter.
Critical Depth .. .
Critical Slope .. .
Froude Number ... .
26.50:1 (H:V)
0.00: 1 (H:V}
0.015
0.0071 ft/ft
2.10cfs
0.27 ft
2.15 fos
0.98 sf
7.19ft
7.47 ft
0.27 ft
0.0067 ft/ft
1.03 (flow is Supercritical)
EXHIBIT 2
Triangular Channel Analysis & Design
Open Channel -Uniform flow
Worksheet Name: NIMITZ ST . TOWNHOMES
Comment: Cooner Street, Q-100 Post Dev.
Solve For Depth
Given I nout Data:
Left Side Slope,.
Right Side Slooe.
Manning's n ..... .
Channel Slope .. ..
Discharge ....... .
Computed Results:
Deoth ........... .
Velocity ....... ..
Flow Area ....... .
Flow Top Width .. .
Wetted Perimeter.
Critical Depth .. .
Critical Slope .. .
Froude Number ... .
26.50:1 (H:V)
0.00: 1 (H:V)
0.015
0.0071 ft/ft
3. 14 cfs
0.32 ft
2.38 fos
1.32 sf
8.37 ft
8.69 ft
0.32 ft
0.0063 ft/ft
1.05 (flow is Suoercritical)
Ooen Channel Flow Module. Version 3.21 (c) 1990
Ha es tad Methods. Inc. * 37 Brookside Rd * hterbury, Ct 06708
• . T
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846-8868
Mrs. Veronica Morgan, P.E.
Engineering Department
City of College Station
College Station , TX
Subject: Drainage Study
March 11 , 1999
Nimitz Street Townhomes
Nimitz St. @ Cooner St.
College Station, TX
Dear Veronica :
Pleased find enclosed the referenced report for your review . This reports covers the
0.36-acre project called the Nimitz Street Townhomes .
Sincerely,
GALINDO ENGINEERS AND PI.ANNERS, INC.
President
cc: Charles H. Szabuniewicz,
Horizon Homes
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GALINDO ENGINEERS AND PLANNERS, I NC.
3833 South Te x as Ave ., Suite 213 Bryan, Texas 77802 (409) 846-8868
1. TRACT DESCRIPTION
NIMITZ STREET TOWNHOMES
COLLEGE STATION, TX
DRAINAGE REPORT
The Nimitz Street Townhomes are to be located at the southeast corner of the intersection of
Cooner and Nimitz Streets. The project covers a 0.36-acre tract formed by Lots 1 and 2, Block
4, Cooner 's Addition. Currently the project area contains one single fam ily , one story,
residence in each of the two lots , neither exceeding 650 s.f. in covered area.
The attached 24" x 36" drawing , Site Plan , depicts the project, existing contour lines and
proposed grading by means of spot elevations .
The adopted Flood Insurance Study does not identify the existence of a 100-flood plain
affecting this tract (Map# 48041 C 0142 C, July 2 , 1992).
2 . STORMWATER RUNOFF
At present the tract drains towards the northeast , as sheet flow, onto Cooner Street.
Exhibit 1 shows the runoff calculations for 5 , 10, 25 , 50 and 100 -year ra infalls . Because of the
size of the tract and the low runoff figures no on site detention is being contemplated .
Upon completion of development the runoff will be conveyed to the northeast of the property
by means of the parking lot driveway. A 2.8 ' curb cut at the northeast of the parking lot will
provide drainage . Exhibit 2, Curb Cut Rating , indicates that this curb cut will allow passage
of 3.1 cfs , an amount corresponding to the 100-yr flow.
Water from the parking lot will then travel to Cooner Street through a 5 '-wide , V-section ,
concrete low flow gutter, 4" deep . Exhibit 2, Concrete Low Gutter Flow , shows that this
gutter can convey 1 .87 cfs , approximately 80 % of the 10-yr flow discharge . The actual
drainage area flowing into this gutter represents 70 % of the total tract area , therefore the 10-yr
flow into the gutter is estimated at 0. 70 x 2.33 = 1.63 cfs , which is less than the flow capac ity
of the gutter. ''''''\\\\\\\
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~································ .. ·············~ ~ ~ 425 ; # --"....._====---------------~.r"".i ~.:--:~-~ <;) / ~ .#
CHRISTIAN A. GALINDO, P.E . # 53425, R.P.L. '.· :.<'·~~GIST£-~;:.··~«; .;f
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Job: 8-99 Date: 03/11/99 RUNOFF CALCULATIONS -RATIONAL METHOD NIMITZ TOWNHOMES COLLEGE STATION, TX (County: Brazos) Tc = 10.0 when calc. value < 10.0 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::· :::::::::::::::::::::::::::::::::::::::: Section Soil Type A Acr~s c Veloc. Length T cone. in mi fps ft Cale. Used 5 yrs 10 yrs 25 yrs 50yrs I 100yrs Q 5yrs Q Q Q 10 yrs 25 yrs 50yrs Q 100yrs ------------------------------------------------------------------------------------------------------------------------------------------------------~-------------------------------------------------------------------------------------------------------------------------------------------Pre-development Conditions -------------------------L. D.R. 0. 180 0.600 3.000 100 0.6 10.0 1 .693 8.635 9.861 11.148 Grass 0. 180 0.400 1. 800 200 1. 9 10.0 1 .693 8.635 9.861 11. 148 -------------------------Total 0.360 Maximum Development -------------------------H.D.R. 0. 180 0.750 8.000 100 D.2 10.0 7.693 8.635 9.861 11. 148 H.D.R. 0. 180 0.750 8.000 200 0.4 10.0 1 .693 8.635 9.861 11.148 -------------------------Total 0.360 L.D.R. = Low Density Residential H.D.R. : High Density Residential County: Brazos Constants for use in formula: l=b/(t+dre 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr --------------------------------------------------------b 65.000 i6.000 80.000 89.000 98.000 96.000 e 0.806 0.785 0.763 0 '754 0' 745 0.730 d 8.000 8.500 8.500 8.500 8.500 8.000 'L 11. 639 11.639 11. 639 11. 639 0.83 0.93 1.07 1.20 1. 26 0.55 0.62 0' i 1 0.80 0.84 ----------------------------------------1.38 1.55 1.i8 2' 01 2' 10 1.04 1. 17 1.33 1.50 1.57 1.04 1. 17 1. 33 i.50 1.57 ----------------------------------------2.08 2.33 2.66 3.01 3. 14 m x ::I: OJ =i I ...... I ~ ~~ ~~ ~ tj a} a x ~~ ~ ~ ~ ~ ~ ~ ~ CD (/) .., ~ '< OJ ~@ Ol ~? ~~ ~~ ~ ~ 'fl S'J co ~~ ~
,' t
GALINDO ENGINEERS AND PLANNERS, INC.
3833 South Texas Ave., Suite 213 Bryan, Texas 77802 (409) 846-8868
Triangular Channel Analysis & Design
Open Channel -Uniform flow
Worksheet Name: NIMITZ TOWNHOMES
Comment: 4'-wide Concrete Low Gutter
Solve For Discharge
Given Input Data:
Left Side Slope ..
Right Side Slope .
Manning's n ..... .
Cha nnel Slope ... .
Depth ........... .
Computed Results :
Discharge ....... .
Velocity ........ .
Flow Area ....... .
Flow Top Width .. .
Wetted Perimeter.
Critical Depth .. .
Critical Slope .. .
Froude Number ... .
7.50:1 (H:V)
7.50:1 (H:V)
0.015
0.0060 ft/ft
0.33 ft
1.87cfs
2.29 fps
0.82 sf
4.95 ft
4.99 ft
0.33 ft
0 '0061 ft/ft
1.00 (flow is Critical}
Open Cha nnel Flow Module, Version 3.21 (c) 1990
Haestad Methods, Inc. * 37 Broo kside · Rd* Waterbury, Ct 06708
2-98
03/11 /99
EXHIBIT 2
_NIMITZ STREET TOW NHOMES
Curb Cut Rating
:::::::::::::::::::::::::::
Use Weir Equation:Q=C*L*(H)'3/2
where Q: discharge , cfs
and L= length of curb cut, ft
and H= height of curb, ft
and C = 3.087
------------------------------------------------------
L H H'3/2 Q A v
l . ft ' I . ft. l ' ft ' cf s sq .ft". ft/sec
------------------------------------------------------
I. 0 0.50 0.35 1. 1 0.5 2' 2
2.0 0.50 0.35 2.2 1. 0 2.2
2.8 0.50 0.35 3' 1 1. 4 2.2
3.0 0.50 0.35 3.3 1. 5 2.2
-
03/31/99 14:49 '6'409 764 3496 DEVELOPMENT SVCS
TRANSMISSION OK
TX /RX NO.
CONNECTION TEL
CONNECTION ID
START TIME
USAGE TIME
PAGES
RESULT
*************************** *** ACTIVITY REPORT ***
***************************
7058
9p8468868
03 /31 14:47
02'25
4
OK
~001
04/14/99 12:30 '8'409 764 3496 DEVELOPMENT SVCS
TRANSMISSION OK
TX/RX NO .
CONNECTION TEL
CONNECTION ID
START TIME
USAGE TIME
PAGES
RESULT
*************************** *** ACTIVITY REPORT ***
***************************
7184
9p8468868
04114 12 :29
00 '41
1
OK
~001