HomeMy WebLinkAbout16 DP Ball Memorial Sub. 04-48 Ph 2 Lt 8 BLK 3Drainage Report
for
Replat of L.O. Ball Memorial Subdiv ision
Phase 2, L ot 8 , Block 3
College Station , T ex as
August 2004
Developer:
Dennis Husfeld & Rostell Chapn1an
420 Tarrow Street
College Station, Texas 77840
(979) 255-3788
Prepared By:
TEXCON General Contractors
1707 Graham Road
College Station, Texas 7 7845
(979) 764-7743
CERTlFICATlON
I , Joseph P. Schultz, Licensed Profess ional E n g in eer No . 6588 9 , State of Texas, certify th a t thi s report
for the drainage d es ign for the Rep lat of L.O . Ball Memorial Subdivision , Phase 2, Lot 8 , Block 3 in
College Station, Texas, was prepared by me in accordance with the provisions of th e C it y of C oll ege
Station Drainage Policy and Design Sta ndards for the owne rs hereof. This proj e ct is only to construct
the infrastructure for the subdivision . Detention facility d es ign will b e provided with eac h commercia l
deve lopment in th e subdivision .
-.""<:"!."'ll.~,~ --~E OF ?',(:-\'\ ~"'~ ................. ~ '
:: 0 •• •• * ··."!& •• ~ * .. ' •• * '1. f*: ... ~ .; ................................... ~
1 JOSEPH P. SCHULTZ I ~················ .................. 2 ~~... 65889 .:sJ f 0 ·.")>~ <c,_Q ." l.Jj l1 fa~·· .. q,S TE~···· ~;
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TABLE OF CONTENTS
LONGMIRE SUBDIVISION
C ERTIFICATION .................................................................................................................................................................. 1
TABLE OF CONTENTS ........................................................................................................................................................ 2
LIST OF TABLES .................................................................................................................................................................. 2
INTRODUCTION ................................................................................................................................................................... 3
GENERAL LOCATION AND DESCRIPTION .................................................................................................................. 3
FLOOD HAZARD I NFORMATION .................................................................................................................................... 3
DEVELOPMENT DRAINAGE PATTERNS ....................................................................................................................... 3
DRAINAGE DESIGN CRITERIA ...................................................... , ................................................................................. 3
STORM WATER RUNOFF DETERMINATION .............................................................................................................. .4
STORM SEWER PIPE & INLET DESIGN ......................................................................................................................... 5
CONCLUSIONS ..................................................................................................................................................................... 6
APPENDIX A .......................................................................................................................................................................... 7
Time of Co11ce11tratio11 Data & Calculatio11 s ............................................................................................................. 7
APPENDIX B .......................................................................................................................................................................... 8
Storm Sewer /11/et D e sig11 Data & Calculatio11s ......................................................................................................... 8
APPENDIX C .......................................................................................................................................................................... 9
Storn! S e wer Pipe D esig 11 Data & Calculatio11s ......................................................................................................... 9
EXHIBIT A ............................................................................................................................................................................ 18
Drainage Area Map -Storm Sewer Inlet Desig11 ..................................................................................................... 18
EXHIBIT B ............................................................................................................................................................................ 22
Drai11age Area Map -Storm S e wer Pipe Design ..................................................................................................... 22
LIST OF TABLES
TABLE 1 -Rain fa ll Intensity & Runoff Data .......................................................................................... 4
TABLE 2 -Time of Concentration (tc ) Equations .................................................................................. 4
DRAINAGE REPORT
REPLAT OF L.O. BALL MEMORIAL SUBDIVISION, PHASE2, LOT 8, BLOCK 3
INTRODUCTION
The purpose of this report is to provide the hydrological effects of the construction of the
infrastructure for the Replat of L.O . Ball Memorial Subdivision, Phase 2 , Lot 8, Block 3
project, and to show that the storm water runoff will be controlled in such a manner so as to
have minimal offsite or downstream impact.
GENERAL LOCATION AND DESCRIPTION
The project is located on 2.748 acres located in College Station, Texas. The site is open land
with grass. The existing ground elevations range from elevation 306 to elevation 298. The
general location of the project site is shown on the vicinity map in Exhibit A.
FLOOD HAZARD INFORMATION
The project site is located in the Lick Creek Drainage Basin. The site is located in a Zone X
Area according to the Flood Insurance Rate Map (FIRM) prepared by the Federal Emergency
Management Agency for Brazos County, Texas and incorporated areas dated February 9, 2000 ,
panel number 48041C0201 D . Zone X Areas are determined to be outside of the 500-yr
floodplain . This site is not within the limit of study for the FIRM.
DEVELOPMENT DRAINAGE PATTERNS
The storm water runoff from the site flows into Longmire Drive or Birmingham Drive and then
into the existing storm sewer system and ultimately into the North Fork of Lick Creek . The
runoff from this development will be discharged into the existing storm sewer system either by
the proposed storm sewer piping or overland flow to the streets where it is conveyed along the
gutter to the existing inlets. The drainage area boundaries are shown on Exhibits A & B.
DRAINAGE DESIGN CRITERIA
The design parameters for the storm sewer are as follows:
• The Rational Method is utilized to detem1ine peak storm water runoff rates for the
storm sewer design .
• Design Storm Frequency
Storm sewer system
• Runoff Coefficients
Undeveloped areas
10 and 100-year stom1s events
c = 0.30
• Rainfa ll Inten s it y equati o ns and '"du es for Bra1os Count y c an be fo und in Tabl e I .
• Time of Concentration, tc -Calc ulation s for are based on the method fou nd in the TR-
55 publication . Refer to Appendix A for the equatio ns and calcu lations. Th e draina ge
runoff f1ow paths used for calculat ing the tim es of co ncentration for the desi g n are
shown in Exhibits A & B . For smaller drainage areas, a minimum tc of 10 minutes is
used to determine the rainfall int e nsity va lu es.
STORM WATER RUNOFF DETERMIN AT ION
The peak runoff va lu es were detennined in accordance with the criteria presented in the
previo u s section for the 10-, 25-and 100-year stonn events . The runoff coeffici e nts are
based on the existing conditions of this tract. The drainage areas are shown in Exh ibits A
& B . Exhibit A has the drainage areas used for the storm sewer inlet design and Exhibit B
has the drainage areas used for the storm sewer pipe design. Runoff conditions are
summarized in Table 1. The time of concentration equations are shown in Tabl e 2 .
TABLE 1 -Rainfall Intensity & Runoff Data
Area c 10 year storm 25 year storm 100 year storm
tc Area# (acres) 110 010 125 0 25 1100 0 100
A, (min) (in/hr} (cfs) (in/hr) (cfs) (in/hr) (cfs)
101 6 .05 0.30 34 .5 4.537 8.23 5.221 9 .48 6 .217 11 .28
102 0 .06 0.30 10 8 .635 0 .16 9.861 0 .18 11 .639 0.2 1
20 1 5.53 0.30 34 .1 4.569 7 .58 5.258 8.72 6 .260 10 .38
202 0 .92 0.30 10 8 .635 2.38 9 .861 2 .72 11 .639 3.21
203 0 .06 0.30 10 8 .635 0 .16 9 .861 0.18 11.639 0 .21
204 0.4 2 0.30 10 8.635 1.09 9 .861 1.24 11 .639 1.47
205 0.86 0.30 10 8 .63 5 2 .23 9 .861 2 .54 11.639 3.00
The Rational Method :
Q=CIA I = b I (tc+d)e
Q =Flow (cfs)
A= Area (acres)
C = Runoff Coeff.
le= Time of concentration (min)
tc = L/(V*60)
L = Length (ft)
I = Rainfall Intensity (in/hr)
Bra zos County:
10 year storm
b = 80
d = 8 .5
e = 0 .763
25 vear storm
b = 89
d = 8.5
e = 0.754
100 year storm
b = 96
d = 8 .0
e = 0 .730
V = Velocity (ft/sec)
TABLE 2 -Time of Concentration (tc) Equations
Th e time of concentration was determined using methods found in TR-55, "Urban
Hy dro logy for Small Watersheds. " The equ ations are as follows:
Time of Concentration :
For S ha ll ow Co ncentrated F low:
Tc = T1(s hcc t ll ow) + Tt(co nccntratcd s heet ll ow)
w h e re : T, =Travel Time , minutes
T, = L I (60 *V)
where : T, =trave l time , minutes
V =Velocity , fp s (S ee 1-"i g 3-1, Ap p . A)
L = fl ow length , fee t
Re ier to App end ix A fo r ca l c ul ation s.
STORM SEWER PIPE & INLET DESIGN
This project consists of the construction of th e pri vate drivew ay a nd stom1 sewer sys te m
a nd the public water and sanitary sewer lin es for thi s d eve lopm e nt. No buildin gs o r
structures are proposed at this tim e. Th e private stom1 sewer system is d es ig ned to collect
the runoff from Lots SA -SF and di sc h arge it into a propos e d public storm sewer pip e
which will connect to th e existing stonn sewer system . The private dri veway a nd th e
proposed stom1 sewer pipe system a nd inlets are d es ig ned for the existing conditions of th e
property.
Development of this property and th e adjacent property will require d etention fac i Ii ti es so
the capacity of the proposed and existing storm sewer systems are not exceeded . Pipes 4 &
5 will be constructed with the ends plugged until development of Lots 7 or SC. Inlets and
additional storm sewer piping will be required when the development plan for eac h lot is
prepared. A drainage report shall be prepared for eac h lot before it is deve loped in order to
verify that the calculated runoff valu es used in this report are not exceeded .
As previously stated , the storm water runoff from this site will be collected by the
proposed storm sewer system and then discharged into the existing storm sewer system.
The storm sewer piping for this project has been selected to be Reinforced Concrete Pip e
(RCP) meeting the requirements of ASTM C-76 , Class III pipe meeting the requirements
of ASTM C-7S9 . The curb inlets will be cast-in-place concrete.
Appendix B presents a summary of the storm sewer inlet design parameters and
calculations. The inlets were designed based on a l 0-year design storm. As p er College
Station guidelines, the capacities of inlets in sump were reduced by 10% to allow for
clogging.
Inlets are at the low point in the driveway. The capacities for these inlets in sump (Inlets 1
& 2) 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 B . There are no inlets on grade proposed for
this development.
Appendix C contains a summary of the storm sew er pipe design parameters and
calculations. All pipes are l S" in diam e te r or lar ge r. The pipes for the stom1 sewer syst e m
were designed based on the l 0-year storm event, and they will also pass the l 00-year
storm event. Based on the depth of flow in the dri vew ay determined for the 100-year
storm event, this runoff will be containe d within th e driveway until it e nt e rs th e sto m1
sewer system. The ve locity of flow in the stonn sewer pipe system is not low e r th an 2 .5
feet per second, and it do es not exceed 15 fee t pe r second. As the data shows , eve n durin g
low flo w conditions, the ve locit y in th e pipes will exceed 2.5 feet p e r seco nd a nd prevent
sedim e nt build-up in th e pipes. The maximum fl ow in th e stom1 sewe r pip e sys te m w ill
occ ur in Pip e No. 1. T h e maximum ve loc it y for th e pipe system in thi s d eve lop me nt w ill
be 6.8 feet pe r seco nd a nd w ill occur in Pip e o . 1. Appendix C contains a s umm a ry of
the pip e ca lc ul a ti ons a s w e ll as a s umm ary of th e flows th roug h th e s to 1111 se wer sys te m for
the 10 a nd 100 -ye ar eve nt s.
A g rading plan for this site has been provided with the construction drawings.
CONCLUSIONS
This project will slightly increas e the storm water runoff from this site due to the
construction of the private driveway. However, the increased flow due to this construction
should not have a significant impact on the surrounding property. Any additional
development on this site will require detention facilities . No flood damage to do w nstream
or adjacent la ndowners is expected as a result of this developme nt.
APPENDIX A
Time of Concentration Data & Calculations
Time of Concentration Calculations
Pre-Developmellt Draillage Area 101:
Sh eet Flow #I : Flo w length = 200 ' = L
Slope = 0.75 %
n = 0 .24 , den se gras s
P2 = 4 .5"
tl = 0 .007 (0 .24 * 200)0
"8
(4 .5)°"5 (0.0075)04
t, = 0 .517 hour s= 31 .0 minute s
Sh a llo w Conc entrated Flo w: l s t Segment Flow length = 277 ' = L
Slope = 0.83 %
For unpaved surface at 0 .83%, Velocity (V) = 1.5 fp s (see Fig. 3-l )
~ t1 =277 ' I (60 *1.5) = 3.1 minutes
Flo w Through Drainage Pip e: Segment Flow length = 130 ' = L
Slope = 1.00 %
From Manning Pipe Calculator data , Velocity, V = 6 .1 fp s
t 1 = 130' I (60*6. l) = 0.4 minutes
Tc= 31 .0 + 3 .1 + 0.4 = 34.5 minutes
Pre-Development Drainage Area 102: Us ing Tc = I 0 minutes
Pipe4_10yr.txt
Manning Pipe calculator
Given Input Data :
shape .......................... .
sol vi ng for .................... .
Diameter ....................... .
Fl owrate ....................... .
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
7.5800 cfs
0.0100 ft/ft
0.0140
11.9256 in
1.7671 ft2
1. 2427 ft2
34.2339 1n
56.5487 in
6.0995 fps
5.2274 in
66.2535 %
9.7540 cfs
5.5197 fps
Page 1
Time of Concentration Calculations, continued
Post-Development Drainage Area 201:
Sh eet Flo w#/: Flow le ngth = 200 ' = L
Slope = 0 .75%
n = 0 .24, den se grass
P 2 = 4.5"
t, = 0 .007 (0.24 * 200)08
(4 .5)05 (0.0075)04
t1 = 0 .517 hour s= 31.0 minutes
Shallow Conc entrated Flow: 151 Segment Flow length= 277 ' = L
Slope= 0 .83%
For unpaved surface at 0.83%, Velocity (V) = 1.5 fps (see Fig. 3 -1 )
t 1 = 277' I (60* l.5) = 3.1
Tc= 31.0 + 3 .1 = 34.1 minutes
Post-Development Drainage Areas 202 tltru 205: Using Tc = 10 minutes
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APPENDIXB
Storm Sewer Inlet Design Data & Calculations
Replat of LO. Ball Memorial Subdivision, Phase 2, Lot 8, Block 3
Inlet Length Calculations
Inlets In Sump 10 year storm 100 year storm
Inlet#
1
2
Length
Flow from A c 010 Ocarry over
Area# (acres) (cfs) (cfs) from Inlet#
5' 102 0 .06 0 .3 0 .16 0.00 -
10 101 6 .05 0 .3 8.23 0.00 -
Transverse (Crown) slope (ft/ft)
= 0.0200
Straight Crown Flow (Solved to find actual depth of flow, y):
Q = 0 .56 • (zln) • S 112 • y8 '3 ~ y ={QI (0.56 • (zln) • S 112]}318
n = Roughness Coefficient =
S = Street/Gutter Slope (ft/ft)
y = Depth of flow at inlet (ft)
Capacity of Inlets on grade :
Oc = 0 .7 * [1/(H 1 -H2 )] * [H 1
512 -H/12
]
Oc = Flow capacity of inlet (cfs)
H 1 =a + y
0.013
H2 = a = gutter depression (2" Standard; 4" Recessed)
y = Depth of flow in approach gutter (ft)
Orotal O rota1+1oe;.
(cfs) (cfs)
0 .16 0 .17
8.23 9 .06
Y10..actual gutter depth L10-Roq 'd .
L10-actual 0100 Ocarry over
(ft) (in) (ft) (ft) (cfs) (cfs) from inlet#
0 .060 0.72 0.13 5 0 .21 0 .00 -
0 .268 3.21 6.78 10 11 .28 0 .00 -
·using Yrnw. = 7" = 0 .583'
z = Reciprocal of crown slope
= 50
Inlets in sumps. Weir Flow:
L = QI (3 * y312 ) ~ y = (QI 3L)213
L = Length of inlet opening (ft)
Q = Flow at inlet (cfs)
y = total depth of flow on inlet (ft)
max y for inlet in sump = 7" = 0.583'
O rotal O rotal+10-;.
(cfs) (cfs)
0 .21 0 .23
11 .28 12 .41
Y100-inlet
(ft) (in)
0 .062 0 .74
0 .555 6 .6 6
APPENDIXC
Storm Sewer Pipe Design Data & Calculations
Replat of LO. Ball Memorial Subdivision , Phase 2 , Lot 8 , Block 3
p · C I If 1pe a cu a ions
Inlet Outl et 10-year s t o rm 1 OO·y ear s t o rm
P ipe# Size Length Slope
Invert E lev Invert Elev 0 10 V 10 T ravel Time, tr10 0 100 V 100 Travel Time, tnoo
%Full % Fu ll
(in) (ft) (%) (ft) (ft) (cfs ) (fps) (sec) (m in) (cfs) (fps ) (s ec) (m in )
1 (Public) 27 91 .8 0 .74 294.85-294 .1 7 13.43 6.4 52 .5 14 0 .24 18 .28 6.8 64 .0 13 0 .22 --
2 (P rivate) 27 152 .2 0.59 296.25 295 .35 13.43 5.8 56 .3 26 0 .44 18 .28 6 .2 69.4 25 0.41 -----
3 (Private) 24 25 .0 0.56 296.49 296 .35 11 .05 5.4 61 .8 5 0 .08 15 .06 5.7 78.4 4 0 .07 --
4 (Private) 18 112 .8 1.00 297 .93 296 .80 7 .58 6 .1 66 .3 18 0.31 10.38 6 .2 89 .7 18 0 .30
-· --
5 (Private) 18 121 .2 0 .76 297.91 296 .99 2 .38 4 .1 36 .2 29 0.49 3.21 4.5 42 .6 27 0.45
Pipe 1 -Public
0 10 Area 201 , 202, 203, 204 , 205 13.43 cfs
0 100 Area 201 , 202 , 203 , 204 , 205 18 .28 cfs
Pipe 2 -Private
0 10 Area 201 , 202, 203 , 204 , 205 13.43 cfs
0 100 Area 201 , 202, 203 , 204, 205 18.28 cfs
Pipe 3 -Private
0 10 Areas 201, 202, 204 11 .05 cfs
0 100 Areas 201 , 202 , 204 15.06 cfs
Pipe 4 -Private
0 10 Area 201 7 .58 cfs
0 100 Area 201 10 .38 cfs
Pipe 5 -Private
0 10 Area 202 2 .38 cfs
0 100 Area 202 = 3.21 cfs
Pipe 1 -10 Year Storm
Ma nni ng Pipe Calculator
Gi ve n Input Data:
Shape .......................... .
Solving fo r .................... .
Diame te r ....................... .
Flowrat e ....................... .
S l ope .......................... .
Mann i ng's n .................... .
Computed Resul t s :
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimete r ...................... .
Velocity ....................... .
Hy draulic Radiu s ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Ci r c u l a r
Depth of Flow
2 7 .0000 in
13 .4300 cfs
0.0074 ft/ft
0. 0140
14.1780 in
3.9761 ft2
2.1151 ft2
43 .7680 in
84 .8230 in
6.3496 fps
6.9589 in
5 2 .5110 %
24.7387 cfs
6.2219 fps
Pipe 1 -100 Yea r Storm
Manning Pipe Cal c ulator
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 vel o city ............. .
Replat o f L.O . Ball Me moria l S ubd i v is i o n
Ph ase 2 , L o t 8, B] oc:k J
Col l ec:;1e S L ,,, . i 0 11 , Tc ·.->•:'~
Circular
Depth of Flow
27.0000 in
18.2800 cfs
0.0074 ft/ft
0. 0140
17 .2672 in
3 .9761 ft2
2 .6851 ft2
50.0472 in
84.8230 in
6.8079 fps
7 .7258 in
63 .9524 %
24.7387 cfs
6 .2219 fps
Pipe 2 -10 Year Storm
Manning Pipe Cal culator
Gi ve n 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 ............. .
Circu lar
Depth of Flow
27.0000 in
13. 4300 cfs
0 .005 9 ft/ft
0. 0140
15.1985 in
3.9761 ft2
2 .3057 ft2
45.8175 in
84.8230 in
5.8248 fps
7.2465 in
56 .29 07 %
22.0895 cfs
5.5556 fps
Pipe 2 -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 ............. .
Re pla t o f L.0 . Ball Me mo r i a l Subdi v i s i o n
Pha se 2 , Lo t 8, Bl o c k 3
1 · ' I I e~J'. ~-; l: a t i o 11 , Te;-: <1:;
Circular
Depth of Flow
27.0000 in
18.2800 cfs
0.0059 ft/ft
0.0140
18.7333 in
3 .9761 ft2
2.9441 ft2
53.1598 in
84.8230 in
6 .209 0 fps
7.9751 in
69.38 2 7 %
22 .08 95 cfs
5.5556 fps
Pip e 3 -1 0 Yea r S t orm
Manning Pipe Cal c ulat o r
Given I nput Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results:
Depth .......................... .
Area ........................ ·. · ·
Wetted Area .................... .
Wette d Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow vel oc ity ............. .
Circular
Depth of Flow
2 4 .0000 in
11 . 0500 cfs
0.0056 Et/Et
0.0140
14.8371 in
3.1416 ft2
2.0392 ft2
43 .4275 in
75 .3982 in
5.4188 fps
6 .7617 in
61 .8212 %
15 .7198 cfs
5.0038 fps
Pipe 3 -100 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for ................... ' ..
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
We t ted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
. Full flow v elocit y ............. .
Repl a t of L.0. Ball Me moria l Su b di vis ion
Ph ase 2 , Lo t 8, Block 3
Coll ci,:1c St;1tin11, '!'("·:;"
Circular
Depth of Flow
24.0000 in
15 .0600 cfs
0 .0056 ft/ft
0 . 0140
18.8229 in
3.1416 ft2
2.6433 ft2
52 .2135 in
75 .3982 in
5.6974 fps
7 .2899 in
78.4286 %
15.7198 cfs
5.0038 fps
Pipe 4 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Result s:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
18.0000 in
7.5800 cfs
0.0100 ft/ft
0 . 0140
11 .9256 in
1 .767 1 ft2
1 .2427 ft2
34.2339 in
56.5487 in
6.0995 fps
5.2274 in
66.2535 %
9.7540 cfs
5.5197 fps
Pipe 4 -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 velocity ............. .
Re plat oE L.O . Bal] Me morial S u b d i v i s i o n
Ph ase 2 , Lot 8, B l oc k 3
Colle<J · S t,:1t:.ic11, Tc:-:«~:
Circular
Depth of Flow
18.0000 in
10 .3 800 cfs
0.0100 ft/ft
0 .0140
16.1416 in
1.7671 ft2
1.6708 ft2
44 .7724 in
56 .5487 in
6.2127 fps
5 .3736 in
89 .6756 %
9.7540 cfs
5.5197 fps
P i pe 5 -10 Year Storm
Ma nni ng Pipe Calculator
Gi ve n I npu t Data:
S hape .................... · · · · · · ·
S o l v ing f or .................... .
Diame t er ....................... .
Fl ow r a t e ....................... .
Slope .......................... .
Ma nning 's n .................... .
Com put ed Resul ts:
Ci rcular
De p th o f F l ow
1 8.0000 i n
2.3800 c f s
0 .0 076 f t /ft
0.0140
De pth . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 . 513 0 in
Area ........................... .
Wetted Ar ea .................... .
Wetted Perimeter ............... .
Perimete r ...................... .
Velocity ....................... .
Hy draul i c Radiu s ............... .
Percent Full ................... .
Full fl ow Flowr ate ............. .
Full flow v eloc i t y ............. .
1.7 6 71 f t 2
0.5767 ft 2
23.2 3 4 7 in
56.5487 in
4 .1 2 6 9 fps
3.574 2 in
36 .1 833 %
8.503 4 cfs
4 . 811 9 fps
Pipe 5 -100 Year Storm
Manning P i pe Calculator
Giv en Input Data :
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
Wetted Area .................... .
Wetted Perimet e r ............... .
Perimeter ...................... .
Velocity ....................... .
Hydr aulic Radius ........... · .... .
Percent Ful 1 ................... .
Full flo w Flowrate ............. .
Full fl ow ve l oc ity ............. .
Repla t o f L 0 . Bal l M e m o ~ial S ubdi v is i o n
Ph ase 2 , Lot 8, B lod-. "3
('I' I J e '~.: f' ~~ t: .: I I_ l C• I 1 , T r · .·: , ·
Circular
Depth of Flow
18 .0000 in
3 .2100 cfs
0 .0076 ft/ft
0 . 0140
7 .6 6 50 in
1.7671 ft2
0.7173 ft2
25 .5945 in
5 6 .5 4 87 in
4 .475 0 fps
4.0358 in
42 .58 3 5 %
8.5 03 4 cfs
4 .811 9 fps
EXHIBIT A
Drainage Area Map -Storm Sewer Inlet Design
I ,.
"
P&Z CASE NO.:
DATE SUBMITTED :
FINAL PLAT APPLICATION
(Check one) 0 Minor
($300 .00)
0 Amending
($300.00)
0 Final
($400 .00)
0 Vacating
($400.00)
~Replat
($600.00)*
*In cludes publi c hea rin g fee
The following items must be submitted by an established filing deadline date for P&Z Commission consideration .
MINIMUM SUBMITTAL REQUIREMENTS:
v Filing Fee (see above) NOTE : Multiple Sheets -$55 .00 per additional sheet
~Variance Request to Subdivisio n Regulations -$100 (if applicable)
~ Development Permit Appl icati on Fee of $200 .00 (if applicable).
V Infrastructure Inspection Fee of $600 .00 (app lica ble if any public infrastructure is being constructed)
v Application completed in full .
V Copy of original deed restrictions /c ovenants for rep lats (i f applicable ).
~Thirteen (13) folded copies of plat. (A signed mylar orig in al mus t be submitted after staff review .)
J1jA One (1) copy of the approved Preliminary Plat and/or one (1) Mas ter Plan (if applicab le) .
._./ Paid tax certificates from City of College Station , Brazos County and College Stat ion l.S.D.
/ A copy of the attached checklist with all items checked off or a brief explanation as to why they are not.
V Two (2) copies of public infrastructure plans associated with this plat (if applicable).
1ljs.. Parkland Dedication requirement approved by the Parks & Recreation Board, please provide proof of
approval (if applicable).
Date of Preapplication Conference: __ 6rx:--+-~[ _I _U~'t-, _zro_~_ 4-~· --------------
NAME OF SUBDIVISION Rtqzial o(-L -D-B0l tYlew10ricJ ~d !v 1>11 01'\fh -2 1 Lo+£J!>fod;;_ .3
SPECIFl_ED LOCATION OF PROPOSED SUB~IVISION (Lot &_Block) ttt c.orn« ~ kwi~m;re t
{>!crotV\()ham / a.cxo5S Lorvg~1re froW\ i.<ro5v-Shb'Pf1~ ~
APPLICAN T/PROJECT MANAGER'S INFORMATION (Prima ry Contact for the Project):
Name "\<co±eJ l C~c<A\
Street Address 1UJ lairoW $ire>eX
State ·f'}. Zip Cod e J l'D lfO
Phone Number (q1q) UD -71g57J
~ Co ti elf Shiii try)
E-Mai l Address ___________ _
Fax Number (q1q) '24-~ -]<j Lft-.
PROPERTY OWNER'S INFORMATION:
Name ~Ro_,__,,,_s f .......... eJ~'t ~CVl-&1-'-vil_el-Y\~-~~-~~~~'--s--+fhs--=--==---£'-"-"'-eJ"'-"-'d......___-=--__ ~ __
Street Address Jtlo rax('oi,0 Sir at City _c,...-"'·o_._,{l-=t:<jf'+'--..,,;L-St~Ji ........ "fu/\'--'-+---
State "ff-. Zi p Code 11'Q/ff) E-Mail Add ress ___________ _
Phone Number (j1q') ?daO _."]lo 5 3 Fa x Number (q19) e4t, --:--]j'2....4-:
ARC HIT ECT OR ENGINEER'S INFORMATION
Name Jee_ SvhlA--l-t:b 1 ?. E. -Tex_c...on
Street Address \:Jen &~VY) J<.J. City L-oli-eA-€. St"l...+J'on
State \j._ Zip Code 11~5 E-M ail Add cess tt,\\'L@-\-e->«c,,,neJ
Phone Number ( q1~ 11.:A,.: -1"]lt3 Fax Number (j _') _ -ltS4
6/13/03 I 1t1 .::..
Drainage Report
for
Replat of L.O. Ball Memorial Subdivision
Phase 2 , Lot 8, Block 3
College Station , Te x as
August 2004
D eveloper:
Dem1is Husfeld & Rostell Chapman
420 Tarrow Street
College Station, Texas 77840
(979) 255 -3788
Prepared By:
TEXCON General Contractors
1707 Graham Road
College Station, Texas 77845
(979) 764-7 743
CERTIFICATION
I, Joseph P . Schultz, Licensed Professional Engineer No. 65889, State of Texas, certify that this report
for the drainage design for the Rep lat of LO . Ball Memorial Subdivision , Phase 2, Lot 8, Block 3 in
College Station, Texas, was prepared by me in accordance with the provisions of the City of College
Station Drainage Policy and Design Standards for the owners hereof. This project is only to construct
the infrastructure for the subdivision. Detention facility design will be provided with each commercial
development in the subdivision.
TABLE OF C ONTENTS
LONGMIRE SUBDIVISION
CERTIFICAT IO N .................................................................................................................................................................. 1
TABLE OF CONTENTS ........................................................................................................................................................ 2
LIST OF TABLES .................................................................................................................................................................. 2
INTROD UCT ION ................................................................................................................................................................... 3
GENE R AL LOCATION AND DESCRIPTION .................................................................................................................. 3
FLOOD HAZARD INFORMATION .................................................................................................................................... 3
DEV ELOPMENT DRAINAGE P ATTERNS ....................................................................................................................... 3
DRAINAGE DE SI GN CRITERIA ......................................................................................................................................... 3
STORM WATER RUNOFF DETERMINATION .............................................................................................................. .4
STORM SE\VER PIPE & INLET DES IGN ......................................................................................................................... 5
CONCLUSIONS ..................................................................................................................................................................... 6
APPENDIX A .......................................................................................................................................................................... 7
Time of Co11ce11tratio11 Data & Calculatio11s ............................................................................................................. 7
APPENDIX B .......................................................................................................................................................................... 8
Storm Sewer !11/et Desig11 Data & Calculatio11s ......................................................................................................... 8
APPENDIX C .......................................................................................................................................................................... 9
Storm Sewer Pip e Desig11 Data & Calculatio11s ......................................................................................................... 9
EXHIBIT A ............................................................................................................................................................................ 18
Drainage A re a Map -Storm Sewer !11/et D esig11 ..................................................................................................... 18
EXHIBIT B ............................................................................................................................................................................ 22
Drainage A rea Map -Storm Sewer Pipe D esig 11 ..................................................................................................... 22
LIST OF TABLES
TABLE l -Rainfall Intensity & Runoff Data .......................................................................................... 4
TABLE 2 -T im e of Co nc entration (t c ) Equations .................................................................................. 4
DRAINAGE REPORT
REPLAT OF L.0. BALL MEMORIAL SUBDIVISION, PHASE2, LOT 8, BLOCK 3
INTRODUCTION
The purpos e of this report is to provide th e hydrolo g ic a l effects of th e construction of the
infrastructure for the Replat of L.O . Ball Memorial Subdivision, Phase 2, Lot 8 , Block 3
project, and to show that the sto1m water runoff will be controlled in such a m an ner so as to
have minim a l offsite or downstream impact.
GENERAL LOCATION AND DESCRIPTION
The project is located on 2.748 acres located in College Station , Texas. The site is open land
with grass. The existing ground elevations range from elevation 306 to elevation 298. The
general location of the project site is shown on the vicinity map in Exhibit A.
FLOOD HAZARD INFORMATION
The project site is located in the Lick Creek Drainage Basin. The site is located in a Zone X
Area according to the Flood Insurance Rate Map (FIRM) prepared by the Federal Emergency
Management Agency for Brazos County, Texas and incorporated areas dated February 9, 2000,
panel number 48041C0201 D . Zone X Areas are determined to be outside of the 500-yr
floodplain. This site is not within the limit of study for the FIRM.
DEVELOPMENT DRAINAGE PATTERNS
The storm water runoff from the site flows into Longmire Drive or Birmingham Drive and then
into the existing storm sewer system and ultimately into the North Fork of Lick Creek . The
runoff from this development will be discharged into the existing storm sewer system either by
the proposed storm sewer piping or overland flow to the streets where it is conveyed along the
gutter to the existing inlets. The drainage area boundaries are shown on Exhibits A & B.
DRAINAGE DESIGN CRITERIA
The design parameters for the storm sewer are as follows:
• The Rational Method is utilized to detem1ine peak storm water runoff rates for the
storm sewer design .
• Design Storm Frequency
Storm sewer system
• Runoff Coefficients
Undeveloped areas
I 0 and 100-year storms events
c = 0.30
• Rain rail Int e ns it y equation s and va lue s lor Br<1 7.0s Co unt y ca n be ro und in Tabl e I .
• T im e o f Co nc e nt ra ti o n , tc -Ca lc ul a ti o ns for a re based o n th e m e th od fo un d in th e T R -
55 publ ica tion . R e fe r to App e ndi x A fo r th e equ a tions a nd ca lculati o n s. T h e d ra in age
runo ff fl ow paths used for calcul a ting th e tim es of concen tra ti o n for th e d es ig n a re
shown in E xhibits A & B . For small e r drainage a re as , a minimum tc of 10 minut es is
used to d e te m1ine th e rainfall int e nsity valu e s .
STORM WATER RUNOFF DETERMINATION
The peak runoff values were det e m1in ed in accordance with th e c rit e ri a pre s e nt ed in th e
prev ious sec tion for th e l 0-, 2 5-a nd l 00-year stom1 ev ents . T he runoff coeffi c ie nt s a re
b a sed on th e e xisting conditions of this tract. The drainage a reas a re sho w n in Ex hibits A
& B. Exhibit A has the drainage areas us ed for the storm sewer inlet d esign and Ex hibit B
has the drainag e areas used for th e stom1 sewer pip e design. Runoff conditions a re
summari z ed in Table 1. The time of concentration equations are shown in Table 2 .
TABLE 1 -Rainfall Intensity & Runoff Data
Area c tc 10 year storm 25 year storm 100 year storm
Area# (acres) 110 010 125 025 1100 0100
Ai (min) (in/hr) (cfs) (in/hr) (cfs) (in/hr) (cfs)
101 6.05 0 .30 34 .5 4 .537 8 .23 5.221 9.48 6 .217 11 .28
102 0 .06 0.30 10 8 .635 0 .16 9 .861 0.18 11 .639 0 .21
201 5.53 0 .30 34 .1 4 .569 7 .58 5.258 8 .72 6 .260 10 .38
202 0 .92 0 .30 10 8 .635 2 .38 9 .861 2.72 11 .639 3.21
203 0 .06 0 .30 10 8 .635 0 .16 9 .861 0.18 11 .639 0 .2 1
204 0 .42 0 .30 10 8.635 1.09 9 .861 1.24 11 .639 1.4 7
205 0 .86 0 .30 10 8.635 2 .23 9 .861 2.54 11 .639 3.00
The Rational Method:
Q=CIA I = b I (tc+d)0
Q =Flow (cfs)
A= Area (acres )
C = Runoff Coe ff.
le= Time of concentration (min)
tc = L/(V*60)
L = Length (ft)
I = Ra infall Intensity (in /hr)
Brazos County:
10 year storm
b = 80
d = 8 .5
e = 0 .763
25 year storm
b = 89
d = 8 .5
e = 0 .754
100 year storm
b = 96
d = 8 .0
e = 0 .730
V = Velocity (fUsec)
TABLE 2 -Time of Concentration (tc) Equations
Th e time of concentratio n was determin ed using methods fou nd in TR-55 , "Urban
Hy dro lo gy for Small Wa ters heds . " The equ at ions are as fo ll ows:
Time of C oncentration :
For S h a ll o w C o n ce ntra te d F lo vv :
Re rer to A p p endi x A ro r c al c ul ati o ns .
. 1
Tc = T1(s hce t llow) + T1(co ncc nlralcd s hcc l ll ow)
w he re: T 1 =Tra ve l Time , minu tes
T 1 = LI (60 *V)
w he re: T 1 =tr ave l t im e, min ut es
V =V e lo c it y , fp s (See F ig 3-1, A pp . A )
L = fl o w le n g th , fe e t
STORM SEWER PIPE & INLET DESIGN
This project consists of the construction of the private driveway and stom1 sew e r syst e m
and the public water and sanitary sewer lines for this developm e nt. No buildin gs or
structures are proposed at this time . The private storm sewer system is designed to collect
the runoff from Lots 8A -8F and discharge it into a proposed public stom1 sew e r pip e
which will connect to the existing storm sewer system . The private driveway and the
proposed stom1 sewer pipe system and inlets are designed for the existing conditions of th e
property.
Development of this property and the adjacent property will require detention faci Ii ties so
the capacity of the proposed and existing storm sewer systems are not exceeded . Pipes 4 &
5 will be constructed with the ends plugged until development of Lots 7 or 8C. Inlets and
additional storm sewer piping will be required when the development plan for each lot is
prepared. A drainage report shall be prepared for each lot before it is developed in order to
verify that the calculated runoff values used in this report are not exceeded.
As previously stated, the storm water runoff from this site will be collected by the
proposed storm sewer system and then discharged into the existing storm sewer system.
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 meeting the requirements
of ASTM C-789. The curb inlets will be cast-in-place concrete.
Appendix B presents a summary of the storm sewer inlet design parameters and
calculations . 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 are at the low point in the driveway. The capacities for these inlets in sump (Inlets l
& 2) 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 8. There are no inlets on grade proposed for
this development.
Appendix C contains a summary of the storm sewer pipe design parameters and
calculations. All pipes are 18" in diameter or larger. The pipes for the storm sewer system
were designed based on the l 0-year storm event , and they will also pass the 100 -year
storm event. Based on the depth of flow in the driveway determined for the 100 -year
storm event , this runoff will be contained within the driveway until it enters th e stonn
sewer system . The velocity of flow in the stom1 sewer pipe system is not lower than 2 .5
feet per second, and it does not exceed 15 feet pe r second . As the data shows , e ven durin g
low flow conditions , the velocity in the pipes will ex ceed 2.5 feet per second and preve nt
sediment build-up in th e pipes . The maximum n ow in the storm sewer pipe sys te m w ill
occur in Pipe No . I . The maximum ve locity for th e pipe sys tem in this d e ve lopm e nt w ill
be 6.8 feet per second and will occur in Pip e No . I . Appendix C contains a summ a ry o r
th e pip e cal c ulation s a s we ll as a s umm a ry of th e n ows throu g h the storm se w e r sys te m fo r
th e I 0 and I 0 0 -ye ar eve nt s .
A g rading plan for this site has b ee n provided with th e construction drawi ngs .
CONCLUSIONS
This project will slightly increase the storm water runoff from this site du e to th e
construction of the private driveway. However, the increased flow due to this construction
should not have a significant impact on the surrounding property. Any addition a l
development on this site will require detention facilities. No flood damage to d ow nstrea m
or adjacent landowners is expected as a result of this d eve lopme nt.
APPENDIX A
Time of Concentration Data & Calculations
Time of Concentration Calculations
Pre-Developmeut Drainage Area I OJ:
Sh eet Fl ow#/: F lo w le ngth = 200 ' = L
Slope= 0 .75 %
n = 0.24 , den se gra ss
P2 = 4 .5"
tl = 0 .007 (0.24 * 200)0 8
(4.5)05 (0 .0075)04
tt = 0.517 hours = 31 .0 minutes
Shallo w Concentra ted Flo w: 1st Segment Flow length = 277 ' = L
Slope= 0.83 %
For unpaved surface at 0 .83 %, Velocity (V) = 1.5 fp s (se e Fig. 3-1)
~ t1 = 277 ' I (60* 1.5) = 3 .1 minutes
Flo w Throu g h Drain age Pip e: Segment Flow len gth = 130 ' = L
Slope = 1.00 %
From Manning Pipe Calculator data , Velocity, V = 6.1 fp s
tt = 130' I (60 *6 .l) = 0.4 minutes
Tc= 31.0 + 3 .1 + 0.4 = 34.5 minutes
Pre-Development Drainage Area 102: Using Tc = I 0 minutes
Pipe4_10yr.txt
Manning Pipe calculator
Given Input Dat a:
shape .......................... .
solving for .................... .
Diameter ....................... .
Fl owrate ....................... .
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
7.5800 cfs
0.0100 ft/ft
0.0140
11.9256 in
1. 7671 ft2
1. 2427 ft2
34.2339 in
56.5487 in
6.0995 fps
5.2274 in
66.2535 %
9.7540 cfs
5.5197 fps
Page 1
Time of Concentration Calculations, continued
Post-Development Drainage Area 201:
Sh eet Flow #I : Flow length = 200 ' = L
Slope = 0 .75 %
n = 0.24 , den se grass
P2 = 4 .5 "
ti = 0 .007 (0.24 * 200)0 8
(4.5)05 (0 .0075)04
t1 = 0 .517 hours = 31.0 minutes
Shallow Concentrated Flow : 1 st Segment Flow length = 277 ' = L
Slope= 0 .83 %
For unpa ved surface at 0 .83%, Velocity (V) = 1.5 fps (see Fig. 3-1)
t 1 = 277' I (60* 1.5) = 3 .1
Tc= 31.0 + 3 .1 = 34.1 minutes
Post-Development Drainage Areas 202 thru 205: Using Tc = I 0 minutes
+J ..... -+J .....
QJ
a.
0 ..-
"'
QJ
"' L.
::s
0
0
L.
4U ..... .,
:x
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. 50
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.04
. 02 -
.01 -
.005
I
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I
' I
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J .
b
q, ,,_ b' ~ q, ~ ~,
~~1 v
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2
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4
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6
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I J
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I
Average velocity, ft/sec
'
. . .
I
I
I ,
I I
10
I . . .
Fi1tu~ :1-1.-Av~rair~ v~lociti~s for c•timatinir trJvd tim~ for ;hallow conc~ntrat~d now .
(210-Vl -TR-55 . Second Ed ., June t98G l
-
I
20
., .
APPENDIXB
Storm Sewer Inlet Design Data & Calculations
Replat of L.O. Ball Memorial Subdivision , Phase 2 , Lot 8, Block 3
Inlet Len gth Calculati ons
Inlet s I n Sump 10 y ear storm 100 year storm
Inlet#
1
2
Lengt h Flow from A c 0 10 O c.ury over
A re a # (acres ) (cfs ) (cfs) from Inlet#
5' 102 0 .06 0 .3 0 .16 0 .00 -
10 101 6 .05 0 .3 8 .23 0 .00 -
T ra nsve rse (Crown) slope (ft/ft)
= 0 .0200
Strai g ht Crow n Flow (Solved t o find act ual depth of flow. y ):
Q = 0 .56 • (z/n ) • 5 112 • y8'3 ¢ y ={Q I [0.56 • (z/n ) • 5 112]}318
n = Roughness Coefficient = 0 .013
S = Street/Gutte r Slope (ft/ft)
y = Depth o f fl ow at inlet (ft)
Capa c ity of Inle ts on grade :
O c = 0 . 7 * [1 /(H 1 - H 2)] * [H /12-H 2
512]
O c = Flow ca paci ty of inl et (cfs)
H 1 =a+ y
H2 = a = g utte r depress ion (2" Sta ndard ; 4" Re ces sed )
y = Depth of fl ow i n approach gutter (ft)
O rotal Q Total+1091.
(cfs) (cfs )
0 .16 0 .17
8 .23 9 .06
Y 10-actua l gutter de pth L10-Req'd .
L 10.-actual 0 100 O carry over
(ft) (in) (ft) (ft) (cfs) (cfs ) from inlet#
0 .060 0 .72 0 .13 5 0 .21 0 .00
0 .268 3 .21 6 .7 8 10 11 .28 0 .0 0
·using y_,, = 7" = 0 .583'
z = Reciprocal of crown slope
50
Inlets i n sumps, We i r Flow :
L = QI (3 * y3 '2
) ¢ y = (Q I 3 L)21 3
L = Length of inlet opening (ft)
Q =Flow at inlet (cfs)
y = total depth of flow on inlet (ft )
ma x y for inl et in sump= 7" = 0.583'
O r otal 0 Total+10Y.
(cf s ) (c f s )
0 .21 0 .23
11.28 12.41
Y100.1n 1et
(ft) (i n)
0 .062 0 .74
0 .5 55 6.66
APPENDIXC
Storm Sewer Pipe Design Data & Calculations
Replat of L.0 . Ball Memorial Subdivision, Phase 2 , Lot 8 , Block 3
p· C I If 1pe a cu a ions
In let Out let 10-yea r s t o r m 100-year sto rm
P i pe # S ize Length Slope
0 10 0 100 Invert Elev Inv ert E l ev V 10 Travel T ime, tno V 100 Trave l Ti me , tnoo
% Full % Full
(in) (ft) (%) (ft) (ft) (cfs) (fps) (sec ) (m i n ) (cfs ) (fps) (s ec ) (m i n)
1 (Public) 27 91 .8 0 .74 294.85-294.17 13.43 6.4 52 .5 14 0 .24 18 .28 6.8 64 .0 13 0 .22 ----
2 (Private) 27 152 .2 0 .59 296.25 295 .35 13.43 5.8 56 .3 26 0.44 18 .28 6.2 69.4 25 0.41
. ---------f--·--
3 (Private) 24 25 .0 0 .56 296.49 296.35 11.05 5.4 61.8 5 0.08 15 .06 5.7 78.4 4 0 .07
--
4 (Private) 18 112 .8 1.00 297 .93 296 .80 7 .58 6 .1 66.3 18 0.31 10 .38 6.2 89 .7 18 0 .30
-·
5 (Private) 18 121 .2 0 .76 297.91 296 .99 2 .38 4 .1 36.2 29 0.49 3 .21 4 .5 42 .6 27 0.45
Pipe 1 -Public
0 10 Area 201 , 202 , 203, 204 , 205 13.43 cfs
0 100 Area 201 , 202 , 203 , 204 , 205 18 .28 cfs
Pipe 2 -Private
0 10 Area 201, 202, 203 , 204 , 205 13.43 cfs
0 100 Area 201, 202, 203 , 204 , 205 18 .28 cfs
Pipe 3 -Private
0 10 Areas 201, 202, 204 11.05 cfs
0 100 Are as 201, 202, 204 = 15.06 cfs
Pipe 4 -Private
0 10 Area 201 7 .58 cfs
0 100 Area 201 = 10 .38 cfs
Pipe 5 -Private
0 10 Area 202 2.38 cfs
0 100 Area 202 = 3 .21 cfs
Pipe 1 -10 Year St o rm
Manning Pipe Cal c ulator
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
13. 4300 cfs
0.0074 ft/ft
0.0140
14.1780 in
3.9761 ft2
2. 1151 ft2
43.7680 in
84.8230 in
6.3496 fps
6.9589 in
52. 5110 %
24.7387 cfs
6.2219 fps
Pipe 1 -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
18.2800 cfs
0.0074 ft/ft
0. 0140
17.2672 in
3.9761 ft2
2.6851 ft2
50.0472 in
84.8230 in
6.8079 fps
7.7258 in
-63.9524 %
24.7387 cfs
6.2219 fps
Replat o f L .0 . Ba ll Me mor i al S ubd i v is i o n
Pha se 2, Lo t 8 , Block 3
College S t ~tion. T PxJ~
Pipe 2 -10 Year Storm
Manning Pipe Calculator
Gi ven Input Dat a:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning's n .................... .
Computed Results:
Depth .......................... .
Area ........................... .
We tted Area .................... .
Wetted Perimeter ............... .
Per imeter ...................... .
Velo city ....................... .
Hy draulic Radius ............... .
Percent Full ................... .
Full flow Flowrate ............. .
Full flow velocity ............. .
Circular
Depth of Flow
27.0000 in
13 . 4300 cfs
0.005 9 ft/ft
0 . 0140
15 .1985 in
3 .9761 ft2
2.305 7 ft2
45 .8175 in
84.8 230 in
5.8248 fps
7 .2465 in
56.2907 %
22.0895 cfs
5.555 6 fps
Pipe 2 -100 Ye a r 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 ....................... .
Hy draulic Radius ............... .
Percent Full .................... .
Full flow Flowrate ............. .
Full flow v elocity ............. .
Replat of L.0. Ball Memoria l Subdivision
Phase 2, Lot 8, Block ·i
'"•I l e~y '· ::L ,7 1t io 11 , Te;-:,1::
Circular
Depth of Flow
27.0000 in
18 .2800 cfs
0.0059 ft/ft
0 . 0140
18.733 3 in
3 .9761 ft 2
2.9441 ft 2
53.15 98 in
84.823 0 in
6.2090 fps
7 .9751 in
69.38 27 %
22.0895 cfs
5 .5556 fps
Pipe 3 -10 Year Storm
Manning Pipe Cal culator
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
24.0000 in
11.0500 cfs
0.0056 ft/ft
0.0140
14.8371 in
3.1416 ft2
2.0392 ft2
43.4275 in
75.3982 in
5.4188 fps
6.7617 in
61.8212 %
15.7198 cfs
5.0038 fps
Pipe 3 -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 ............. .
Rep la t o f L.O. Ball Memoria l Subd ivisio n
Ph ase 2 , Lot 8, Bl oc k l
Col l ee,,· Sti.1t ion , Tc·::,;.·
Circular
Depth of Flow
24.0000 in
15.0600 cfs
0 .0056 ft/ft
0. 0140
18.8229 in
3.1416 ft2
2.6433 ft2
52.2135 in
75.3982 in
5.6974 fps
7 .2899 in
78.4286 %
15.7198 cfs
5.0038 fps
Pipe 4 -10 Year Storm
Manning Pipe Calculator
Given Input Data:
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Man ning'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
7.580 0 cfs
0.0100 ft/ft
0 .0140
11.9256 in
1. 7671 ft2
1.2427 ft2
34 .2 339 in
56.5487 in
6.0995 fps
5.2274 in
66.2535 %
9.7540 cfs
5.5197 fps
Pipe 4 -100 Year Storm
Manning Pipe Calculator
Giv en I nput 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 ............. .
Replat o f L.0 . Ball Mem or i a l S ubdi v i sio n
Ph ase 2 , Lo t 8, Bl oc k 3
C'ol l ec 1' ~:;i:-,1 ti on . Te:·:d~:
Circular
Depth of Flow
18 .0000 in
10.3800 cfs
0 .0100 ft/ft
0 .0140
16.1416 in
1.7671 ft2
1.6708 ft2
44 .7724 in
56 .5 487 in
6.2127 fps
5.3736 in
89.6756 %
9.7540 cfs
5.5197 fps
Pipe 5 -10 Year Storm
Manning Pipe Calculator
Given I nput 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 .00 00 in
2.3800 cfs
0.00 76 ft/ft
0 .0140
6.5130 in
1.7671 ft2
0.5767 ft2
23.2347 in
56.5487 in
4.1269 fps
3.5742 in
36.1833 %
8.503 4 cfs
4 .8119 fps
Pipe 5 -100 Year Storm
Manning Pipe Calculator
Given Input Data :
Shape .......................... .
Solving for .................... .
Diameter ....................... .
Flowrate ....................... .
Slope .......................... .
Manning' s n .................... .
Computed Results :
Circular
Depth of Flow
18 .0000 in
3.2100 cfs
0 .0076 ft/ft
0 . 0140
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 . 6650 in
Area ........................... .
Wetted Area .................... .
Wetted Perimeter ............... .
Perimeter ...................... .
Velocity ....................... .
Hydraulic Radius ........... · .... .
Percent Full ................... .
Full flow Fl owrate ............. .
Full flow velocity ............. .
Replat of L .O . Ball Memo t·ia l S ubd .i v i sio n
P h ase 2 , Lot 8, B loc f'. l
(·'c, I J C'tJC' ~~t: .;1 l. i C•11, ·r·,··::
1.7671 ft2
0.7173 ft2
25 .5945 in
56.5487 in
4.4750 fps
4.0358 in
42.5835 %
8.503 4 cfs
4 .8119 fps
EXHIBIT A
Drainage Area Map -Storm Sewer Inlet Design
I S