HomeMy WebLinkAboutDrainage ReportDrainage Report
for
Northgate Proper Apartments
College Station, Texas
February 2013
Developer/Owner:
Bona Fide Acquisitions, LLC
4400 Old College Road
Bryan, Texas77801
Prepared BY:
Schultz Engineering, LLC
TBPE Firm No. 12327
P.O. Box 11995
College Station, TX 77842
2730 Longmire Drive, Suite A
College Station, Texas 77845
(979)764-3900
. Drainage Report — Executive Summary
Northgate Proper Apartments
College Station, Texas
ENGINEER
Schultz Engineering, LLC
P.O. Box 11995
College Station, Texas 7-7842_
-- Phone: O �64 = 3900
OWNER/DEVELOPER
Bona Fide Acquisitions, LLC
C/O Justin Whitworth
'- 4400 Old College Road
f Bryan, Texas 77801
Phone: (979) 703-8925
GENERAL DESCRIPTION AND LOCATION
This project c 8%-Qf the development of vacant lots on Tauber Street in College Station, Tx. This NG-3
zoned site project will inel de. the construction of a multi -family building, sitework, utilities and other
infrastructure.
The development includes Block 2, Lots 6-10 Tauber Addition on Tauber Street. The project lots are
r located at the northeast corner of the intersection of Tauber Street and Cherry Street.
y
Area: 0.76 acres
Existing Land Use: NG-3
Proposed Land Use: Ng-3 Multi -Family
Number of Lots: 4
Drainage Basin: Burton Creek Watershed
FEMA FIRM: #48041C0305E Dated May 16, 2012 _
of loodplain: None..of the development lies within the floodplain.
HYDROLOGIC CHARACTERISTICS
`- The pre -development condition of the land was developed with duplex housing and driveways. Exhibit A
shows the pre -development and post development drainage areas and the runoff flow direction.
GENERAL STORMWATER PLAN
The drainage plan for this development will involve the installation of an onsite underground detention
facility. 36" diameter pipes will be used to provide the majority of the storage volume. The storm runoff
will collect in the parking area & drainage areas around the building and flow into the detention facility
through a series of grate inlets and pipes. The detention facility will capture the proposed storm water
runoff and convey it through the outfall structure and into a relocated storm sewer inlet on Cherry Street.
The proposed detention pond will capture the proposed storm runoff and discharge at a rate equal to or less
than the existing design flows. A small portion of the building roof runoff, parking lot and grass areas will
bypass the detention facility and discharge directly into the surrounding streets similar to existing flow
patterns. The combination of area bypassing the detention pond and the detention pond outflow will be less
than or equal to the pre -developed condition for the site. Exhibits B & C show the post development
topography and the runoff flow direction. Exhibit D is the Drainage Plan showing the pipe and inlet sizes.
-- Page 1 of 5
Drainage Report — Executive Summary
Northgate Proper Apartments
College Station, Texas
COORDINATION & STORMWATER PERMITTING
U The project will not require a permit to be prepared to comply with the Texas Commission for
Environmental Quality storm water permitting for the construction site, because the site is less than 1 acre.
`— No other permits are anticipated for this project.
DRAINAGE DESIGN
General Information: Stormwater runoff from the development will be collected and routed through
the detention facility and then discharged into the relocated storm sewer inlet on
- Cherry Street. A small portion of the building roof runoff, parking lot, perimeter
landscaping and grass areas will bypass the detention facility and discharge
directly into the surrounding streets similar to existing flow patterns. The
—` combination of area bypassing the detention pond and the detention pond
outflow will be less than or equal to the pre -developed condition for the site.
The runoff enters the detention pond from the parking lot through a series of
grate inlets and area inlets around the building and storm sewer pipes. The Roof
drainage may be piped directly into the private storm sewer & detention
facilities or discharged into the parking lot and then into the storm sewer system.
The detention pond consists of a series of storm sewer pipes in various locations
throughout the site as shown on Exhibits B, C & D.
`— Detention Facility Analysis
T, Methodology: TR 55
T, Minimum: 10 minutes
Design Storm Events: 2-year, 10-year, 25-year, 50-year and 100-year detention facility
Pond Discharge Pipe
-- Materials: HDPE private storm sewer pipe
Manning's n Value: 0.013
Runoff Coefficients: 0.53 for existing conditions & 0.95 for developed conditions
Design Constraints: Max. water depth in the parking lot = 6 in. or 0.5 ft. for 100 year storm event.
Min. flow velocity = 2.5 fps
Max. flow velocity =15 fps
Post -Development peak runoff less than or equal to existing storm water runoff
from the site.
Rational Equation: The rational equation is utilized to determine peak storm water runoff rates for
the Detention Facility design.
Q=CIA
Q = Flow (cfs)
A = Area (acres)
C = Runoff Coefficient
I = Rainfall Intensity (in/hr)
Design Software: Excel spreadsheets, AutoCAD Hydraflow Express, AutoCAD Hydraflow
Hydrographs Extension
Page 2 of 5
Drainage Report — Executive Summary
Northgate Proper Apartments
College Station, Texas
The software was used to compute the pond storage and discharge data arrd the
pre and post -development peak runoffs and the routing of the flow through the
detention pond.
Design Results: The data presented in the Appendices and in the following tables indicates the
detention pond sizing and discharges are in accordance with the requirements of
the design guidelines. Refer to Appendix B for design calculations for tb e area
inlets.
Applicable Exhibits: Exhibit A — Pre -development Drainage Area Map
Exhibit B — Post -development Detention Area Map
Exhibit C — Post -development Inlet Area Map
Exhibit D — Drainage Utility Layout
Appendix A — Drainage Area Summary— Detention Facilities
Appendix B — Drainage Area Summary — Inlets, Pipe & Inlet Design Surnmary
Appendix C — Detention Facility Data and Hydrographs
Design Analysis: The post -development drainage areas are shown on Exhibits B & C. The design
data and descriptions of the detention facility outlet structures and discharge are
found in Appendix C. Exhibit D shows the pipe and inlet sizes. A small portion
of the building roof runoff, parking lot, landscaping and grass areas will bypass
the detention facility and discharge directly into the surrounding streets similar
to existing flow patterns. The combination of area bypassing the detention pond
and the detention pond outflow will be less than or equal to the pre -developed
condition.
Sedimentation in the detention facility is not likely due to the small drainage
areas that are mostly paved areas and the use of underground detention in storm
sewer pipes.
The peak flow out of the detention ponds were determined by a Storage Routing
Analysis based on the Continuity Equation as follows: (Il+I2)+((2s1/dt)-
0l)=((2s2/dt)=02). The time interval, dt, used was 1 minute. The calculations
and results of the Storage Routing Analysis were used to generate hydrograph
peak flows and graphs for the pre and post development conditions. A summary
of the pre and post development runoff information from the site is shown in
Table 2.
The detention pond discharges into the storm sewer system on Cherry Street.
TABLE 1— Pre- & Post -Development Peak Discharge Comparison
Area #
Area (Acres)
C
Tc
Pre
101
0.75
0.53
10
Post
301
0.65
0.95
10
Post
302
0.10
0.95
10
Page 3 of 5
Drainage Report - Executive Summary
Northgate Proper Apartments
College Station, Texas
As shown in Table 2, the post -development peak outflow from the project site is
less than the allowable peak outflow for each design storm event. Additionally,
Tables 3 presents the maximum water surface and the amount of freeboard for
the Detention Facility. The peak flow out of the detention Facility and the
maximum water surface was determined by the Storage Routing Analysis.
TABLE 2- Pre- & Post -Development Runoff Information - Detention Analysis
Q2
Q10
Q25
Q50
Q100
Location
cfs
cfs
cfs
cfs
cfs
Pre -Development
2.51
3.43
3.92
4.43
4.63
(Area 101) _
Post Development with Detention
Post -Development
3.91
5.33
6.09
6.88
7.19
(Area 301)
Post -Development
0.60
0.82
0.94
1.06
1.11
(Arm 302)
Pond Outfall
1.89
2.18
2.33
2.52
2.60
(Area 301 Routed Through Pond)
Combined Outflow
2.28
2.67
2.87
3.08
3.17
(Compare to Area 101)
Decrease in Peak Flow
0.23
0.76
1.05
1.35
1.46
TABLE 3 - Summary of Pond 1 Maximum Water Surface Levels
Storm Event
Peak Flow out of
Pond, (cfs)
Water Surface
Elevation, ft.
Freeboard
ft.
2-year
1.89
340.62
3.68
10-year
2.18
341.27
3.03
25-year
2.33
341.66
2.64
50-year
2.52
342.16
2.14
100-year
2.60
342.38
1.92
Page 4 of 5
Drainage Report — Executive Summary
Northgate Proper Apartments
College Station, Texas
Top of Inlet (Detention Facility) = 344.30, Spillway Crest Top of Pavement = 344.80'
(Low Point in Parking Lot)
The detention facility is controlled by an 8" outfall pipe. The outfall discharges
from Inlet 101.
The 100 year water surface is below the rim elevations of the inlets. If the pond
outlet clogs, the water will pond in the low areas of the parking lot and grass
areas. The water will pond to a depth of 6" or less before running over the low
point in the parking lot or sidewalk into the public right of way and be conveyed
to the existing streets.
CONCLUSION
The onsite detention facility for the development will function within the requirements and restrictions of
the BCS Drainage Design Guidelines.
CERTIFICATION
"This report for the drainage design of the "Northgate Proper Apartments" was prepared by me in
accordance with the provisions of the Bryan/College Station Unified Drainage Design Guidelines for
the owners of the property. All licenses and permits required by any and all state and federal
regulatory agencies for the proposed drainage improvements have been issued."
S(
_C
Deven L. Doyen, P.E.
Page 5 of 5
Pre -Development Drainage Area Map
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KERB DUD I Ol1D I JPB 1 12-204 FEBRUARY 2013
—51
i
NORTHGATE PROPER PRE -DEVELOPMENT SCALE EXHIBIT
APARTMENTS DRAINAGE AREA
NORTHGATE MAPS ,.,
COLLEGE STATION, TEXAS R4L'WIE, 12-204
r*:;�i:
Post -Development Detention Area Map
--__..
-" —_— "--�—.:.:;art.\ �
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EXHIBIT C
Post -Development Inlet Area Map
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EXHIBIT D
Drainage Plan
AE AE
FL=340.60
AE
INLET 101 S
Q 24" GRATE INLET
RIM: 344.30 PIPE 102
36" HDPE PIPE FL IN: 339.00 Gj� 36' HDPE PIPE
B" HDPE PIPE FL OUT: 338.50 / 14.0 LF Q 0.00%
0-k 91
S�
/ FITTING 102
w TEE
Q 5� 36" HDPE PIPE FL IN: 339.06
36` HDPE PIPE FL IN: 339.06
FLOW BREAK POINT / 36" HDPE PIPE FL OUT: 339.06
/ IN PARKING LOT Gj
FITTING 103
REPLACE 15 LF OF /E- 90' BEND
STORM SEWER PIPE __4 36" HDPE PIPE FL IN: 339.06
AND CONNECT TO PIPE 100 36" HDPE PIPE FL OUT: 339.06
RELOCATED INLET 8" HOPE PIPE
53.3 LF Q 1.00%
5
" 8" STORM FL=337.99. I
° 6" SEWER FL=340.07
1�,
I
rn
E AE AE AE AE
s s�=� s 6 s-�6� 5---5-- s-s
PIPE 101 FITTING 105
PIPE
90' BEND
1 LF
10.7 LF Q 0.50%
36" HDPE PIPE FL OUT: 339.81
FITTING 101
36"
HDPE PIPE FL OUT: 339.8-1
-
TEE
36" HDPE PIPE FL IN: 339.06
PIPE 104
=-
PIPE 105
-
-
36" HDPE PIPE FL IN: 339.06
3fi' HDPE PIPEPIPE-
36' HDPE PIPE FL OUT: 339.06
150.8 LF ® 0.50%
50.8 LF Q 0 50%
PIPE 110
ST ST - T ST
ST - ST
- ST
ST S�
ST - S
ST
ST ST
ST S ST
ST - ST
ST -
T - ST
ST - ST
5T
T
36" HDPE PIPE
ST
4.o LF Q o.00%
FITTING 106
ST - ST ST - ST
ST - ST - ST - ST - ST ST ST ST - ST
ST ST ST -
ST ST ST ST ST ST ST ST ST ST
TEE
36" HDPE PIPE FL IN: 339.81
36` HDPE PIPE FL OUT: 339.1S1
36" HDPE PIPE FL OUT: 339.13t
ST ST ST - ST
ST - ST ST ST ST ST
I/
10 5 0 10
SCALE IN FEET
ST ST ST ST T ST ST ST ST ST ST ST - ST NOTES:
JB JUNCTION
1. ALL TOPSOIL SHALL BE SALVAGED AND
JUNCTION BOX INLET 104
PIPE 106 1- PIPE 109 STOCKPILED FOR REUSE.
PIPE 103 FITTING 104 (A RIM: 348.16 24' GRATE INLET - V-5724-1
36" HDPE PIPE 15` HDPE PIPE FL IN: 341.65 RIM: 347.69
36` HDPE PIPE TEE 36" HDPE PIPE
100.E LF Q 0.50% PIPE 107 2.5 LF Q 0.00% 2. BACKFlLL ALL PROPOSED PARKING LOT
5.0 LF Q 0.00% 15' HDPE PIPE FL IN: 340.48 I 36' HDPE PIPE FL IN: 339.81 12' HDPE PIPE FL IN: 342.44 ISLANDS WITH FULL DEPTH TOPSOIL
36' HDPE PIPE FITTING 107 D
36" HDPE PIPE FL IN: 339.56 36' HDPE PIPE FL OUT: 339.81 12" HDPE PIPE FL IN: 342.44 PIPE 114 45' BEND (48.0 LF Q 0.50% INLET 10336" HDPE PIPE FL OUT: 339.5615" HDPE PIPE FL OUT: 342.27 3. ALL STORM SEWER PIPE, EXCEPT AS
►- EHD
INLET - V-5724-1 PIPE 112 16. HDPE PIPE 12" HDPE PIPE FL IN:. 342.
� 16.7 LF Q 1.00% NOTED, SHALL BE HDPE. SDR-35,
RIM: 347.70 15" HDPE PIPE 12'-HDPE PIPE FL OUT: 342.62
PIPE FL IN: 341.67 8.3 LF Q 1.00% -- ASTM D-3034, PVC PIPE MAY BE USED
E- IN PLACE OF HDPE PIPE. HDPE PIPE
PE FL OUT: 341.77SHALL MEET AASHTO M294 TYPE S
ST ST -
ST ST ST -
ST ST ST ST
WITH WATERTIGHT SEAL H -� 0 THE
_ _. WEVER .-
S
PROPOSED STORM S T M EWER S.PRIVATE
PIPE 115 - AND.•SHALL.BE INSTALLED IN
•e . • PIPE 113 e D ° . D 12 HDPE PIPE ACCORDANCE' WITH THE LOCAL
D D a DHE
\ 12.3 LF Q 1.00% PLUMBING CODE. THIS INCLUDES THE
�""».-.......-",.l<`"""'�• � •: . a • °D '15' HDPE PIPE �' ' • o a
e
PIPE 111 e D Q 37.3 LF Q 1.00% ' • e ` . PIPE 121 D e PIPE MATERIAL AND FITTINGS. THE
15" HDPE PIPE FITTING 108 CONTRACTOR SHALL VERIFY WITH THE
p rr x.:. r• y: <•Y .+<.:; r ., ._ ;.. 12' NDPE PIPE . :'. f ;r.�_- i -r \ LOCAL BUILDING OFFICIALS THE TYPE
D >Y {; ;.;r> f .: .^•'�'.°:. r ;:ssi.i': 9.7 LF Q 1.00% f z T ': ..>'• ;T;r.' 45 BEND
30.3 LF Q 1.00% g ""=•= r j=••s;;.,n• PIPE 132 OF MATERIALS REQUIRED BY THE CITY
a ?:f,, :•". K: r:,<•: <,i- 12" HDPE PIPE FL IN: 342.74
t. r., r; : :itr. r .:�•, .;, f' _.3-i, 12` HDPE PIPE OF COLLEGE STATION PRIOR TO
r:..•rAp;�'2.y:. '.i%. :,.y ._tom ::5. _r-:•'^. ..c.i`..r "T
`::. ;'.?= .-:w,:,iG:•e: :': - 12' HDPE PIPE FL OUT: 342.75
1'�- - CONSTRUCTION ! "x`:i''t: ;•�inra!t�s� •.�j,; ?•p;.;e; rrr•yY;:R; «r;h INLET 110 r;; ;:t`. 5.1 LF Q 1.00%OF THE STORM SEWER..
t' a •i c%:si"', ra ,^ rIs '.r< s, TRENCH DRAIINLET 102 N "i PIPE 122
24" GRATE INLET - V-5724-1 D '• ` ?"`' ` x`' `;t r xk !.fir. , .:;fir sr RIM: 348.00 ~ i:- ~"` ' k 4. AREA INLETS MAY BE CAST IN PLACE
-c 12 HDPE PIPE
RIM: 347.02 �'-:'i.`' "' r::.;• ' ''': 12" HDPE PIPE FL OUT: 342.56 °r f.s 1.8 LF Q 1.00% OR PRECAST CONCRETE. ALL
R 12" HDPE PIPE FL IN• 340 96 `<=%^* :� ••r ' "%=' CONCRETE FOR DRAINAGE
3
15" HDPE PIPE FL OUT: 340.80
' n
� I--�_�
I_���•
a• ?:l.., r:. r'-.fir:i:5 _Ii�iF•F�S.i
'.,..(L
D • D .a p Dj
.. .° ..
�'F _,£ia`v-••.t �'''i•yZ^,;�_ �c r,,
D e. D e n a.
D
PIPE 127 e o- !n ° D• D
D
a INLET 113 :«3Tv;� r-;:r
l
e D' D D : . D °
12' HOPE
110.1
P
D
LF Q 1.00% D°'
RIM: 347.50
9 D'. 12' HDPE PIPE FL IN
' e a e•
- D'. D D b
I I (
I I
I I I 12" HDPE PIPE FL OUT: 341.68 '•: � r;r;;„-; : ,•fir.
- ( PIPE 129- •r rC?e= s=•'r':'> r':f,p",;...r:•..,.
►.E PIPE
.�
LF-0 530ZA
1►7���lf���>•AG
�r
Y.'� r �`:'µ :.:,:;:ri;�: r �•X
FITTING 109
CONSTRUCTION SHALL HAVE A MINIMUM
TEE
28-DAY COMPRESSIVE STRENGTH OF
'}•; '-'`rY
INLET 105
I
12" HDPE PIPE FL IN: 342.80
3000 PSI.
°_�'� •r; =; ;
12" AREA DRAIN
RIM: 347.00
12" HDPE PIPE FL IN: 342.80
5. STRUCTURAL BACKFlLL AREAS ARE
irr'^•'�'£✓�'T^
12' HDPE PIPE
FL OUT: 342.82
12" HDPE PIPE FL .80 OUT: 342
DEFINED AS ANY TRENCH SECTION
'`"�'����'`'" `
I
UNDER OR WITHIN 3' OF PAVEMENT.
" ' , ''s,::•<
r $ -� - :..: ;. e ,
• '
12 HDPE PIPE
6. JUNCTION BOX STORM SEWER COVERS
INLET 106
15.5 LF Q 1.00%
ARE PRIVATE AND SHALL USE NOT
'
12AREA DRAIN
FITTING 110
"CITY OF COLLEGE STATION* LOGO ON
.-.•ry:>?r•x:�':;
RIM: 347.00
TEE
COVERS.
'j;i`;t� ';=�"'•'%`'=
12' HDPE PIPE FL OUT: 342.96
12' HDPE PIPE FL IN: 342.95
En
A
r`f ' `�iY'
r ; - ;.,,':; a•,., :' t..�
III- 12` HDPE PIPE r`z%.r ' ^.c
12 HDPE PIPE FL IN: 342.95
D'
-I
�;s.;:iy•, :,, ,.,•..c;.:; s yt.•...<_-.; . nr ;:i.:% :•}?:�., ;f'.a.
_
r• h - ' • .,i; `" "'• !. } .
128.5 LF Q 100% r h ur2.,,r 'r,• r>:..<.;., '
'=.•'r`•':s :'•� :';a -L:; ,e'�< : •rL: ~^o^:.. ^-;.?3?:. ,:.. .rr`` >i. <.t:ri+7 •ti i'^:f•; `Y• `r- '3Y >�^
.- .r.�.. -r'- s••
12' HOPE PIPE FL OUT: 342.95
D p• D D p
ST--•--... I
I I I
' D'° ^.�t'•`-.:• r .C_l?•:,; •<''ufC,•y:g _
e ,.�,.�.. e•.'.,i . .T::a,�;;:
s �:f,rq PIPE 'r. � d^;.'.
PIPE 123
_
do
a
_. __
L ,:,sriv::X,.4• p 131
( r • .: a. .;,T_ o- + t,: �•y . , u.:: Z z "• f _= : t� . r''
�•• - • HDPE PIPE '•"C �'ra '':''
I/:h :z.; "
12" HDPE PIPE
[0.4
PIPE 117
114 • n
D'
n-_OT
D .
- -- t:. G ij <: .i
��L4�'� y S�• ram'.• `'+<:F r `."`> 13.8 LF Q 1.00% :yD
S `�J".'=%�'r,•.`-12'
',.,,
LF Q 1.00%FITTING
HDPE PIPE
».... -
90' BEND -
D'
a -
a
• ... - �,_'~"� Tf'4.>->• ,1:.,;r •,s f,:.e:.
ST :r_•,:+..;;,s":x,•y;re� ..;,:•:�;i.;•::,:=�j�::�y�:n„'.=:��..�.:aGr.js.,.
.
z 1'
18.7 LF ®1.00%
12" HDPE PIPE FL IN: 341.08
°'
" r�
B I .
• '
PIPE 128 D
ST , c . r+• :•.*•,rgC'r: .» E•r pto°}.• t
e ----- „ ;>"`'
n ST 3 .,..; x r .T,c,+:
�- ST f
" -- -_
12" HDPE PIPE FL OUT: 341.06
D: c
12" HDPE PIPE
D b ,'s :; .;:`>,-,'j ^Y,ti. D D
Sr -_ - . - --�-t_ . s-•, ,
D D a D n _ --- Sr
PIPE 124
- --
30.0 LF Q 1.00%
r
D n ST °
D
12" HDPE PIPE
PIPE.00X
T
FITTINE 111
"-----�-
INLET 112 : D c ''
D '
7LF Q 1
I
12` AREA DRAIN ° D D . ° p
RIM: 347.50 PIPE 130 ® D
L
11E 2HDPE PIPE FL IN: 343.12
10 HDPE PIPE FL IN: 341.38 'D n
12" HOPE PIPE FL IN: 343.12
-'
NORTHGATE PROPER APARTMENTS
- DD
12" HDPE PIPE FL OUT: 341.39 138 LF HOPE PIPED
12" HDPE PIPE FL OUT 343.12
'`-`-- 3 & 4 STORIES
12" AREA RAIN INLET 114 IN 107
®-
PIPE 118
►
RIM: 347.50 12" AREA DRAIN
112*
12" HDPE PIPE
3.4 LF
55 MAX. BLDG. HT.
12" HDPE PIPE FL IN: 341.83 IN 115
FF
12` HDPE PIPE FL OUT: 341.83 t2•AR HDPE PIPE FL OUT: 343.09
347.550
[10
= 348.30'
RM:
FITTING 112
FITTING 113 '_
26, 603 SF
-'----
HDPE PIPE FL OUT: 341.98
Gj45!
y
BEND
NPIPE ""---
/
12" HDPE PIPE FL IN: 343.15
8" HDPE FL IN: 339.54
2" HDPE PIPE FL 15
8" HDPE PIPE FL OUT: 339.54
PIPE 125
ST --- _ ST
8" HDPE PIPE
- �----
----�
rl
PIPE 119
�- ST - __
ST
114.5 LF Q 5.62%�_
_
--- -, INLET 1D8
12" HDPE PIPE
____
ST
•""- ST--...._ ST ' - ST
INLET 111
_
"'-----.... 24 GRATE INLEr - V-5724-1 �
RIM: 347.DO
/
/
20.7 LF Q 1.00%
10
ST ST
AREA DRAIN
RIM: 347.54`
TOP OF GRATE I
12" HDPE PIPE FL IN: 343.48 '
c�
8 . HDPE�PIPE. FL OUT. 346.00 _
3
12 HDPE PIPE FL OUT:
- 343.38 -
-_- ST --- -
° ° ST
ST p -
_'---� T OF GRATE
34 . TOP F GRATE h
347. T
E-
PIPE 120
PF
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S
FL=339.27
ADD 12 AREA INLETS: , ''' . '►
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TO THESE LOCATIONS
IF NECESSARY :.. �, ., '. ; .. •..': o : ' • :..
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OF
PIPE O.D. T COMPACTED CEMENT STABILIZED
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(6" MIN) ���� �• ONLY. SPADE BY LIFTS INTO
PLACE, TO FILL ALL VOIDS
AROUND PIPE. MANUALLY
CONSOLIDATE AT OPTIMUM
PIPE MOISTURE.
0�
THE TRENCH BOTTOM SHALL BE
GRADED SO AS TO PROVIDE UNIFORM 12" MIN.
AND CONTINUOUS SUPPORT FOR THE
PIPE BARREL BETWEEN BELL HOLES
BEDDING AND TRENCH BACKFILL FOR
HDPE PIPE - STRUCTURAL AREAS
N.T.S.
T T
T �
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6" TOP & ADS NYLOPLAST
BOTTOM SLAB G� #4 BARS 10 O.C.E.W. 6" TOP & GRATE FRAME
EAST JORDAN IRON SIDE WALLS BOTTOM SLAB W/
WORKS, GRATE #
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SMYONA A
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MIN. 2 6"
MANHOLE COVER
SQUARE
28-DAY CONCRETE
AND FRAME 30"
#4 BARS 6" O.C.E.W.
STRENGTH=4000 PSI
O.D. + 6"
TOP & BOTTOM SLAB
PLAN
MIN. 3'
SQUARE
SECTION A -A
GRATE INLET DETAIL
N.T.S.
s�
�SL_Ohvltz Engineering,
2730 Lon mire, Suite A
Longmire,
College Station, Texas 77845
979.764.3900 TBPE NO.12327
SURVEYED DESIGNED DRAWN APPROVED JOB NO. DATE
KERR JPS DLD JPS 12-204 FEBRUARY 2013
28-DAY CONCRETE
STRENGTH 3000 psi PLAN
JUNCTION BOX DETAII..
N.T.S.
NORTHGATE PROPER
NORTHGATE - COLLEGE STATION, TX
NYLOPLAST ROUND
DROP -IN GRATE,
COLOR BLACK 3
12" DIAMETER
UNLESS NOTED'
OTHERWISE
PIPE & GRATE
TO
BE FLUSH
NOTE: INLET SIZE 1S NOTED IN THE PLAN VIEW
NYLOPLAST DROP -IN GRATE
AREA DRAIN DETAIL
N.T.S.
�A/)_ P,, R A I NA U` E P L A N
EXISTING MANHOLE
RIM-
NOTE: ALL PIPING AND FITTINGS
TO BE IN ACCORDANCE
WITH PLUMBING CODE
PROPOSED
ROOF
DOWNSPOUT
4" PIPE
LENGTH VARIES
4" 45' BEND
4" PIPE
LENGTH VARIES
6" PIPE 6' WYE 6" PIPE
BEND
ROOF DOWNSPOUT
CONNECTION DETAIL
SCALE
VERTICAL N/A
HORIZONTAL 1:10
PLOTTING SCALE: 1:1
FILE NAME: 12-204
N.T.S.
APPENDIX A
Drainage Area Summary — Detention Facilities
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APPENDIX B
Drainage Area Summary — Inlets,
Pipe & Inlet Design Summary
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A
APPENDIX C
Detention Pond Data & Hydrographs
Detention Pond
Appendix C
Detention Pond Summary
Detention Facility
Design Storm
Inflow
Outflow
W.S.
Elevation
(yr)
(cfs)
(cfs)
(it)
2
3.91
189
340.62
.............................
-------
34L27----
................10--------...--•
25
-••-5.33 ..
6.09
-- -2.
2.33
341.66
50
6.88
2.52
342.16
100
7.19
2.60
3 42 .3 8
*Top of Pavement = 344.30' - Top of Spillway = 344.8'
Detention Facility
Appendix C
Storage Routing Analysis Parameters
t=60s
Detention Facility
Elevation
Depth
Discharge
Storage
2 s/t
2 s/t + O
(ft)
(ft)
(O, cfs)
(s, cf)
338.50
0.0
0.00
0.0
0.0
0.00
339.00
0.5
0.68
13.9
0.5
1.14
339.50
1.0
1.25
183.7
6.1
7.37
340.00
1.5
1.57
569.8
19.0
20.56
340.50
2.0
1.83
1208.9
40.3
42.13
341.00
2.5
2.06
1949.2
65.0
67.03
341.50
3.0
2.27
2692.8
89.8
92.03
342.00
3.5
2.46
3307.7
110.3
112.72
342.50
4.0
2.64
3781.8
126.1
128.70
343.00
4.5
2.80
4259.2
142.0
144.77
343.50
5.0
2.96
4908.2
163.6
166.57
344.00
5.5
3.11
5652.9
188.4
191.54
* The flow control structure for the smaller storms is a 8" outfall pipe.
Detention Facility Inflow & Outflow Hydrographs
Appendix C
6w'A
-01"flow�Inflo'
,A
-QutfT6
25yri
gyr:
-,,,,5
0 oyi�
l0,
Time(
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(Cfs)
Q(cfs)
Q(Cfs)
E� (Y,
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
OM
0.00
0.39
0.19
0.53
0.28
0.61
0.33
0.69
0.39
0.72
0.41
0.78
0.69
1.07
0.75
1.22
0.79
1.38
0.82
1.44
0.83
1,17
0.78
1.60
0.93
1.83
0.99
2.07
1.04
2.16
1.05
1.56
0.95
2.13
1.10
2.44
1.17
2.75
1.23
2.87 1
1.26
1.95
1.09
2.67
1.26
3.04
1.31
3.44
1.35
3.59
1.37
2.34
1.24
3.20
1.36
3.65
1.42
4.13
1.48
4.31
1.50
2.73
1.32
3.73
1.47
4.26
1.55
4.82
1.60
5.03
1.62
8
3.13
1.41
4.27
1.58
4.87
1.64
5.51
1.70
5.75
1.72
3.52
1.51
4.80
1.67
5.48
1.74
6.20
1.81
6.47
1.84
1.60
J, S 3?,,,'
1.76
04
1.84
-j;'6.'as
1.91
1.94
3.71
1.66
5.07
1.84 1
5.78
1.93
6.54
101
6.83
2.04
3.52
1.71
4.80
1.91
5.48
2.00
6.20
2.09
6.47
2.13
13
3.32
1.76
4.53
1.97
5.18
2.07
5.85
2.17
6.11
2.20
3.13
1.79
4.27
2.01
4.87
2.12
5.51
2.23
5.75
2.27
2.93
1.83
4.00
2.06
4.57
2.17
5.16
2.29
5.39
2.34
2.73
1.85
3.73
2.09
4.26
2.21
4.82
2.34
5.03
2.40
f7"
2.54
1.87
3.47
2.12
3.96
2.24
4.47
2.39
4.67
2.45
2.34
1.88
3.20
2.14
3.65
2.27
4.13
2.43
4.31
2.49
2.15
1.89
2.93
2.16
3.35
2.30
3.79
2.46
3.95
2.53
1.95
1.89
2.67
2.17
3.04
2.32
3.44
2.49
159
2.56
1.76
7777�
2.40
1.19,:
.74
1.33�
3.10
2.50
3.23
2.58
1.56
1.88
2.13
2.18
2.44
2.33
2.75
2.87
2.59
1.37
1.87
1.87
2.17
2.13
2.33
2.41
2.52
2.52
2.60
1.17
1.86
1.60
2.17
1.83
2.32
2,07
2.51
2.16
2.59
0.98
1.85
1.33
2.15
1.52
2.31
1.72
2.49
1.80
2.58
0.78
1.82
1.07
2.14
1.22
2.29
1.38
2.47
1.44
2.55
0.59
59
1.79
0.80
2.11
0.91
2.27
1.03
2.44
1.08
2.52
3 9
0.39
1.76
0.53
2.09
O�61
2.24
0.69
2.41
0.72
2.48
20
0.20
1.72
0.27
2.05
0.30
2.21
0.34
2.38
0.36
2.44
0.00
00
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1.68
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2.02
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2.17
0.00
1 2.33
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2.39
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1.98
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2.13
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2.28
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1.59
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1.94
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2.24
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00
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1.90
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2.20
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2.25
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1.44
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1.86
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2.01
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2.16
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2.21
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1.36
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1.81
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1.97
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2.12
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2.17
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1.29
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1.77
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1.93
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2.08
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2.13
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1.16
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1.72
0.00
1.89
0.00
2.04
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2.09
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0.98
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1.67
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1.85
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2.00
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2.05
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1 0.69
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1.63
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1.81
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1.96
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2.61
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1.76
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1.92
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1.51
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1.72
0.00
1.88
0.00
1.93
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0.00
0.00
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1.44
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1.67
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1.84
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0,00
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1.36
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1.62
0.00
1.80
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1.85
0.00
0.00
0.00
1.28
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1.58
0.00
1.75
0.00
1.81
. . . . . . . . . . . .
M,,_0,00
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1.15
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1.50
0.00
1.70
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1.76
YMN&4
0.00
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0.00
0.96
2 1
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212
1.66
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1.72
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Pre -Development VS. Post Development Hydrographs
Appendix C
iL
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Q k %Y,",j'
(6W,
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Q', (dO
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0.00
1
0.00
0.00
0.00
1
0.00
0.00
6.00
0.00
0.25 .2
0.25
0.34
0.36
0.39
0.43
0.44
0.49
0.46
0.52
0.50
0.81
0.69
0.92
0.78
0.97
0.89
1.03
0.93
1.05
3-
0.75
0.97
1.03
1.17
1.18
1.27
1.33
1.35
1.39
1.38
1.01
1.19
1.37
1.43
1.57
1.54
1.77
1.66
1.85
1.70
1.26
1.39
1.72
1.67
1.96
1.77
2.22
1.88
2.31
1.92
1.51
1.60
2.06
1.85
2.35
1.98
2.66
2.11
2.78
2.17
1.76
1.74
2.40
2.04
2.74
2.20
3.10
2.34
3.24
2.40
2.01
1.89
2.75
2.24
3.14
2.39
3.54
2.55
3.70
2.61
2.26
2.05
3.09
2.41
3.53
2.58
3.99
2.76
4.16
2.83
Z!iv "F
2.20
T_
.58
7,,'
2.78 -
77
2.97
3.05
2.39
2.23
3.26
2.62
3.72
2.82
4.21
3.02
4.40
3.09
12�
2.26
2.25
09
3.09
2.65
3.53
2.84
3.99
3.05
4.16
3.12
2.14
2.27
2.92
2.66
3.33
2.86
3.77
3.07
193
3.14
14
2.01
2.28
2.75
2.67
3.14
2.87
3.54
3.08
3.70
3.16
i
1.89
29 ,,,k�
2.57
2.57
(5
2.94
3.32
3.47
7
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1.76
2.27
2.40
2.66
2.74
2.87
3.10
3.08
3.24
3.17
1.63
2.26
2.23
2.65
2.55
2.85
2.88
3.08
3.01
3.16
1.51
2.24
2NO56
2.63
2.35
2.83
2.66
3.06
2.78
3.15
. . .
1.38
2.22
1.89
2.61
2.16
2.81
2.44
3.04
2.54
3.14
1.26
2.19
1.72
2.58
1.96
2.78
2.22
3.01
2.31
3.11
1.13
2.16
1.54
2.54
1.76
2.75
1.99
2.98
2.08
3.08
1.01
2.12
1.37
2.51
1.57
2.71
1.77
2.94
1.85
3.04
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0.88
2.09
1.20
2.46
1.37
2.66
1.55
2.89
1.62
2.98
0.75
2.04
1.03
2.41
1.18
2.61
1.33
2.83
1.39
2.92
0.63
2.00
0.86
2.36
0.98
2.55
1.11
2.76
1.16
2.85
0.50
1.94
0.69
2.30
0.78
2.48
0.89
2.68
0.93
2.77
0.38
1.88
0.51
2.24
0.59
2.41
0.66
2.60
0.69
2.69
0.25
1.82
0.34
2.17
0.39
2.33
0.44
2,52
0.46
2.59
0.13
1.75
0.17
2.10
0.20
2.26
0.22
2.43
0.23
2.49
0.0
1.68
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2.02
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2.17
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2.33
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2.39
0.00
1.63
0.00
1.98
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2.13
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2.28
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2.35
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1.59
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1.94
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2.09
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2.24
0.00
2.30
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1.52
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1.90
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2.05
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2.20
0.00
2.25
0.00
1.44
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1.86
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2.01
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2.16
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2.21
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1.36
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1.81
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1.97
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2.12
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2.17
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1.29
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1.77
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1.93
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2.08
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2.13
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1.16
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1.72
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1.89
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2.04
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2.09
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0.98
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1.67
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1.85
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2.00
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2.05
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0.69
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1.63
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1.81
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1.96
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2.01
0.00
0.00
0.00
1.58
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1.76
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1.92
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1.97
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0.00
0.00
1.51
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1.72
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1.88
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1.93
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1.44
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1 1.67
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1.84
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