HomeMy WebLinkAbout1990-01-16 Stormwater Report SPR 9-13-89 - Stormwater Report - 0 Annie Sargent School 9/13/1989 TECHNICAL MEMORANDUM:
STORMWATER DENTANTION
CALZETTA SCHOOL
NORTH ANDOVER
MASSAC H US ETTS
PREPARED FOR: WILLIAM PRESSLEY ASSOCIATES
432 COLUMBIA STREET
CAMBRIDGE, MASS.
BY: ENVIRONMENTAL DESIGN & PLANNING, INC.
253 WASHINGTON STREET
BELMONT, MA 02178
617-484-8087
PRINCIPAL- IN - CHARGE: WILLIAM C. PISANO, PE
10 SEPTEMBER 1989
OBJECTIVES :
I) {QUANTIFY NFED FOR ON--SITC STORMWATER DETENTION STORAGE FOR THE
100 YEAR 24 1lOUP STORM AS TO ENSURE THAT POST RUNOFF PEAK FLOW
CONDITIONS TIF NO GREATER THAN PRE PROJECT CONDITIONS
2 ) Df.TTNTION STORAGE IS COMPUTED POR FACILITIES NEAR ABBOT ST FOR
THE "UPPER" AREF AND FOR THE "LOWER" SOUTHERLY PORTION OF THE
PROJECT. IN THE SOUTHERLY PORTION DISCHARGE IS TO A SERIES A
CULVERTS WR ICH PASSES UNDER A PRIVATE DRIVEWAY ( WOLF)-. THIS
OUTLET THEN PROCEEDS TO DRAIN IN A NATURAL CHANNEL PARALLELING
THE PRIVATE DRIVE, AND THEN TURNS AND DRAINS DOWN TO ABBOT ,
TURNS SOUTH - AND PROCEEDS IN A WESTERLY DIRECTION ALONG THE OTHER
SIDE OF THE WOLF PROPERTY.
3 ) ALTHOUGH STORAGE IS COMPUTED FOR r OTH AREAS , A DETENTION AREA
IN THE SOUTHERLY PORTION IS RECOMMENDED AS THE Ndh'tHERLY
REQUIREMENT IS VERY SMALL.
4 ) IT IS INTENDED TO MAINTAIN THE -SAME DEGREE OF WETTING IN THE
MAIN WETLAND AREA. IT IS FURTHER INTENDED TO DRAIN THE FLOW FROM
ONLY THE SCHOOL BUILDING ITSELF INTO THE WETLAND.
5) THE EXISTING POND ON THE SITE APPEARS TO THE GREATER THAN
DESIRED 3 FEET OF WATER DEPTH DESIRED FOR SAFETY ( APPROX 4-4+
FEED AT DEEPEST) IT IS EDP' S UNDERSTANDING THAT THIS WATER DEPTH
IS MEANT TO- BE BELOW THE INVERT OF THE EXISTING CULVERT SYSTEM.
THIS "PROBLEM" IS TO BE SESOLVED IN THE DRAINAGE SOLUTION-.
5 ) ALTHOUGH NOT PART OF THE STORM DRAINAGE ANALYSIS, IT IS
INTENDED TO CROSS "WETLANDS" AND SO ALL AREA FILLED OR ALTERED
IS TO BE REPLICATED.
INTRODUCTION
SINCE THERE IS SUBSTANTIAL DRAINAGE VIA A WETLAND NATURAL
CHANNELWAY THROUGH THE SITE, COMPLETE QUANTITATIVE DELINEATION
OF ALL HYDROLOGIC INPUTS ( ON--SITE AND OFF-SITE) WOULD REQUIRE AN
EXTENSIVE ANLYSIS OF OFF-SITE CATCHMENTS, ETC AND ADDITIONAL
SURVEY WORK-. TO EXPEDITE CALCULATIONS AND RESOLUTION OF REQUIRED
ON SITE DETENTION STORAGE THE FOLLOWING METHOD OF CALCULATION
WAS USED.
FIRST, THE ANALYSIS CONSIDERS ONLY THOSE ON-SITE LAND MASSES
DIRECTLY AFFECTED BY THE PROJECT IE, AREAS WHERE IMPREVIOUSNESS
IS TO CHANGE.
SECOND, THE CONTROL OUTLET POINT. FOR CALCULATIONS ARE THE
DISCHARGE POINT INTO THE SET OF CULVERTS ( SOUTHERLY AREA) AND
THE CULVERT OUTLET ON ABBOT FOR THE NORTHERLY POINTS.
2
0
THIRD, FOR THE LOWER AREA IT IS ASSUMED THAT ALL DIRECT ROOF
DRAINAGE FROM `I'PE SCHOOL WOULD BE DISCHARGED INTO THE WETLAND
WOODED AREA DIRECTLY TO THE SOUTH WITHOUT ANY STORMWATER
MANAGEMENT TO BUFFER PEAK FLOWS. THE SAME ASSUMPTION WAS USED FOR
THE ACCESS ROAD PROM 7CHNSON UP TO THE MAIN CULVERT OUTLET POINT.
FOR PURPOSES OF DISCUSSION ALL OF IRIS AREA IS TERMED „A`.
FOURTH, ALL DRAINAGE FROM EASTERLY ROAD SYSTEM AND ALL PARKING
LOTS WOULD FLOW IN A PIPED SYSTEM AND DISCHARGE INTO A NEW
ELLIPTICAL -- SHAPED OPEN DETENTION POND JUST BEHIND THE LOWER
ORCHARD. FOR PURPOSES OF DISCUSSION THIS CATCHMENT AREA IS TERMED
"B". THE POND STORAGE WOULD BE SUFFICIENT IN SIZE TO OFFSET THE
UNABATED PEAK ROOF LOAD FROM AREA "A"-. FULL ADVANTAGE IS TAKEN OF
AREA "A" ' S HYDROGRAPH "FLATTENING BY DISCHARGE INTO THE WETLANDS.
FIFTH, A VORTEX FLOW THROTLE IS ASSUMED TO CONTROL THE OUTFLOW OF
LOWER POND SUCH THAT THE POND VOLU?E ATTENUATES THE PEAK FLOW
FROM AREA "B" TO NECESSARY LEVEL BUT STILL ALLOWS THE FbT1D TO
DRAIN. POND IS TO BE NO DEEPER THAN 3 ' AND IS TO DRAIN DRY AMD
EACH EVENT.
ANALYSIS
I. DATA
FROM REVIEW OF WPA DRAWINGS, HYDROLGIC PARAMETERS RELEVANT AREAS
ARE NOTED IN TABLE 1•.
RESPECTIVELY. SOILS TYPE WAS ASSUMED TO BE SCS TYPE "B" FROM
INSPECTION OF SITE SOILS BORINGS AND FROM VISUAL INSPECTION OF
AREA.
RAINFALL FOR DESIGN STORMS 2, 5,10,25 AND 100 YEAR 24 HOUR
SYNTHETIC STORMS-- SEE TABLE 2 ( ALSO SEE APPENDIX A FOR
DISCUSSION OF TYPE III SCS RAINFALL EVENT. )
IT. COMPUTATION APPROACH HALSTEAD COMPUTER SOFTWARE:
TR55 & POND PACKAGES-.
III. ANALYSIS
FIGURE 1 : A--B PRESENTS "POST" HYDROGRAPHS FOR ( 10 25 AND
100 YEAR STORM EVENTS ) FOR. ALL "LOWER" FLOW TRIBUTARY TO THE
"PROJECT OUTLET POINT".
3
u
I
Please note that -111 float:- and velumeS computed MUST BE DIVIDED
BY 10 as the areas were scaler € p by 10 to minimize numerical
roundino
FIGURE 2 : A.-5 PRESENTS DESIGN STORPI HYDROGRAPHS FOR "PREEXISTING
CONDITIONS" FOR ALI, "LOWER" FLOW TRIBUTARY TO "PROJECT OUTLET
POINT"
NO DETENTION STORAGE IS CONSIDERED AT THIS POINT.
THE TABLEAU BELOW SUMMARIZES PEAK FLOW CONDITIONS FOR THE LOWER
AREA.
DESIGN STORM PRE PROJECT POST PROJECT
(YEAR) (CFS) (CFS)
*ic*�F�r**** tktkk�kk*�•�*�***9c9cFk*9c* k* Irk�t•h*�cF�rtdrirlc�kk**�' k�* tFknk�c•k*�c*�cltir
2 0-. 2 0 .3 �-
5 1 . 0 6,.7
10 2-.4 7.. 8
2.5 3 . 8 9, 3
100 5 . 4 11. 2
ON—SITE DETENTION STORAGE IS COMPUTED FOR THE 100 YEAR STORM
EVENT USING RUNOFF FROM BOTH AREAS "A" AND "B" -. A TOTAL OF 0-. 44
ACRE—FEET OF STORAGE IS NECESSARY IN THE LOWER AREA TO MAINTAIN
AN OVERALL PRE—PROJECT PEAK OF 5-. 4 CFS( FROM BOTH AREAS)-.
A. SUBSEQUENT ANALYSIS WAS CONDUCTED ON ONLY AREA "B" TO ASCERTAIN
STORAGE VOLUME ( CAPTURING AREA B RUNOFF) VERSUS STORAGE VOLUME
RELEASE RATE. THE OBJECT IS TO CHOOSE A RELEASE RATE SUCH THAT
0•. 44 AC—FT WOULD BE CAUGHT. ITERATIVE RESULTS ARE SHOWN BELOW-.
POND RELEASE RATE STORAGE ( AC—FT) CAUGHT
( CFS )
1-. 0 0-.29
0 5 0-.3 8
0-. 3 3 0-.41
0-. 25 0-.44
THUS A TOTAL OF 0-. 44 AC—FT OF STORAGE RUNOFF WOULD BE DETAINED
PROVIDED THE OUTLET CONTROL ON STORAGE EQUALLED 0-. 25 CFS.
THIS CAN BE REALIZED WITH A VORTEX THROTTLE.
FOR THE UPPER AREA ONLY A TOTAL Or 0-.03 AC—FEET OF STORAGE IS
NECESSARY TO MAI':TAIN PRE PROJECT CONDITIONS-. MINOR EXPANSION OF
THE LOWER AREA SOLUTION IS INSTEAD PROPOSED-.
4
B
SITE RECOMMENDATIONS
A. SOLUTON OF EXISTING POND PROBLEM ,
THE SURFACE AREA OF THE THE EXISTING POND IS ABOUT 11,700 SQ FT.
ASSUME THE POND DEPTH BELOW THE INVERT OF THE OUTLET IS 4 FEET
+/- IF A NEW OUTLET WERE. PROVIDED APPDX-. ONE FOOT LOWER, THE
AVERAGE WATER LEVEL WOULD DROP ONE FOOT TO A MORE DESIREABLE
"SAFE" LEVEL-. DURING STORM EVENTS THIS POOL LEVEL WOULD RISE AND
WET THE ROOTED OF THE VEGATATION ALONG THE EXISTING POND EDGE.
SINCE POTENTIAL DETENTION STORAGE { ASSUME EVAPORATION AND
SEEPAGE LOSSES RESULTS IN WATER SURFACE BELOW INVERT OF OUTLET }
WILL BE LOST BY LOWERING THE EXISTING POND' S OUTLET LEVEL.,,;. IT IS
PROPOSED TO CONSTRUCT A NEW POND IN "UPLAND AREA " THAT WILL HAVE
A VOLUME ( BELOW INVERT OF THE NEW OUTLET) EQUAL TO THE VOLUME
DELETED IN EXISTING POND THUS , THE DETENTION STORAGE RELATED
TO THE SITE' S BUFFERING CAPACITY '-'OP EXOGENOUS FLOW INPUTS WILL
REMAIN UNCHANGED.
SINCE THIS NEW POND WILL HAVE A SURFACE AREA IN EXCESS OF THE
AMOUNT OF WET LAND AREA REQUIRING REPLICATION , IT IS PROPOSED TO
ALSO USE THIS "NEW CREATED POND IN UPLAND AREA" AS THE
REPLICATION OFFFSET. THUS THE NEW POND IS INTENDED TO SATISFY
TWO FUNCTIONAL REQUIREMENTS
PRESERVATION OF EXISTING WETLAND WETTING
THE RAINWATER ROOF LEADERS FROM THE SCHOOL BUILDING WILL BE
CAUGHT, AND DIRECTED TO TWO SEPARATE ROCK FILLED TRENCH SYSTEMS
WITH FAIRLY LEVEL INVERTS. AS OUTLINED ON THE PLANS ROOFWATER
WILL FLOW FROM A HEADER MANHOLE THROUGH OPEN JOINTED PIPE WITHIN
ROCK FILLED TRENCH-. FLOW WILL FILL. INFILTRATE AND THEN OVERFLOW
AND "SHEET" INTO THE WETLANDS TRENCHES WILL BE APPROXIMATELY 3
FEET WIDE BY FOOR FEET DEEP AND FILLED WITH 1-1. 5 " WASHED ROCK
OR LARGER)-. THE UPPER SIDE OF THE TRENCH WILL BE BERNIED TO
PROMOTE FLOW IN THE OTHER DIRECTION TO THE WETLANDS.
COMPENSATORY OFF--SET DETENTION STORAGE PROJECT
A DRY TYPE DETENTION AREA APPROXIMATELY 3 FEET DEEP IN PROPOSED-.
THE LOWER AREA DETENTION STORAGE AREA WILL BE ELLIPTICAL IN
SHAPE ( 127 FEET PY 88 FEET AT THE TC,P ) WITH A BOTTOM FOOTPRINT
( ASSUMING 1 TO 3 SLOPE} OF ABOUT 10S FEET BY 70 FEETOF 120x40
APPROXIMATELY 22,000 + CU FT STOR!.GE WILL BE GENERATEa.
5
THE STORAGE FACILITY WILL BE NO GREATER THAT 3 FEET DEEP AND ITS
NORMAL DISCHARGE WILL BE THROTTLED BY VORTEX DEVICE ( 0 . 25 CFS
LIMIT) THIS DEVICE WILL BE CONTAINED WITHIN A FLOW CONTROL
STRUCTURE THE CONTROL STRUCTURE WILL ALSO SPILLWAY WEIR FOR
EMERGENCY TOPPING -. THE TWO INPUTS TO THE POND WILL BE ENERGY
DISSIPATED VIA A DROP MANHOLE CONNECTIONS.
THE NATURE OF EXISTING TILL WITHIN THE DETENTION AREA WILL
REQUIRE THAT A COMPACTED CLAY LINER , SAY 1 FOOT COMPACTED CLAY
BE PLACED ON THE BOTTOM AND SIDE SLOPES OF STORAGE. A
POLYETHYLENE MEMEBRANE MAY ALSO BE NECESSARY.
THE STORAGE VOLUME WOULD COMPLETELY DRAIN IN A DAY A WET POOL
COULD BE CREATED BUT IS DISCOURAGED FOR SAFETY-.
CROSSINGS
TWO CULVERT CROSSINGS ARE REQUIRED-. IN THE WESTERLY AREA A 12"
RCP SECTION WITH HEAD WALLS ARE DESIRED. THE INVERTS SHOULD BE
JUST ABOVE EXISTING GROUND SURFACE TO PRESENT SILTATION. IN THE
MAIN CROSSING TWIN 24" RCP CULVERTS ARE PROPOSED.
6
"lam-
Chu (-k TR-55 Version : 1. 41 SIN: 87010546
TR--55 TABULAR HYDROGRAPH METHOD
Type III Distribution
(24 hr. Duration Storm)
Executed: 01-01-1980 01 : 31 : 19
Wa' er:shed file ---> C :CLPRE100.WSD Hydrograph File ---->
CALZETTI SCHOOL AUGUST 19 GROSS ANALYSIS
PRE PROJECT CONDITION ( INCREMENTAL ANALYSIS)
AREAS MULTIPLIED BY 10 WIVIDE RESUL't"0 ISY 10
»» Input Parameters Used to Compute Hvdrograph ««
Ss i^area AREA CN�..�__-_TC-___--T�----..
Description (acres) (hrs) (hrs)
_ "
SUB AA 3 .37 65. 00 . 20r--~ r~�O .50
SUB B(3 4-.00 65 .0 0 . 40 0-. 20
SUB Cc 13-.10 65-.0 0 . 30 0.50
SUB [D0 13". 00 65-.0 0 . 30 0 .50
W - ~__. --------
T�"��vFl time from subarea outfallto .
composite watershed outfall point.
Total area 33 . 47 acres or 0•.05230 va.mi
DIVIDE ALL RESULTS BY TEN %=J�
A C& s 5 2-0A D So j�n[ s oI4 -to w i CAN n C 2DSS�.v(r
CC ; vPPE(L OTA T,-,XN-)" jC,oWER Ile" P"K W> Lod
Jv' D DID F007 PkI a. ! SC1{OD C 6 L D6 -f- M tSC . Ckrea Ct rt2U vp
10 vvA/P wV-nAPDs .
i
i
i
1
QL0ck TR--55 Version : 3 . 41 SIN: 87010546 Pace 1 of
TR-55 TABULAR HYDROGRAPH METHOD
Type III Distribution
(24 hr. Duration storm)
Exocuted : 01-01.-1980 00 : 13 :09
ww-orshed File --> C :CLPOS100 .WSD Hydrograph File --> C:CLPS100 . H`
CALZETTI SCHOOL AUGUST 19 GROSS ANALYSIS
POSTPROJECT CONDITION ( INCREMENTAL ANALYSIS)
]AREAS MULTIPLY BY 10/DIVIDE RESULTS :IY 10
>>>> Input Parameters Used to Compute Hydroaraph <<<<
- _.�____�-
Sc�barea ----AREA CN TC * Tt
De:-c-ription (acres) (hrs) thrs)
- ^ --_^^_`-
SUB A 3 .30 98. 0 0 . 20 0 . 40
SUB B 4-. 00 98.0 0 . 20 '1.00
SUB C 13-.10 9 8•.0 0 .10 + .10
SUS? D 13,. 0 0 9 8-.0 0 . 20 50
*- �" raveltimP` ^ ^ �
framsubareaoutfallto-composite water
outfall point.
Total area 33 . 40 acres
�� DIVIDE ALL RESULTS BY TEN _�'�
1'14t� � JtJ►�`�t/L_
C,
�\E L->Y r�✓iC� C`�To�
• Cw. )
Appendix Xt Svnthetic rainfall distributions and rainfall
data Sources
The ;Tighe_: peak discharges from small watersheds
Irl th" UIMC'd t,ite are usually caused by intense.
t,l'lei r'ainialls that nl:iv ,occur as distinct et'entr or ar '
par', -.,f it loner storm. These irate,:: rain:Corms dig
not usually extend Over a large ar,a nd intensities
var,N, LI'eat).\% 01IL' COYII111011 practice in rainfall-runoff
anajv is i,� to develop a synthetic rainfall distribution
10 W11 in lieu of actual storm events. This
distribution includes maximum rainfall intensities for o.s
the selected design frequency arranged in a sequence I
that is critical for producing peak runoff.
Synthetic rainfall distributions
i
0 J 6 S i f
The length Of the most intense rainfall period `
contributing to the peak runoff rate s related to the
:lmE' of concentration (T,.) f„i' the tt'ii orshe(1. Ina fiture . S('S '1-hour rain la11 di>lrihution..
hvrir, wit II Itr,wet 11,11'+•,. th,.
dlt]•ii:ioll (if rainj':J'. that d'irecil.,: contributes to the
leak is about 1 11 percent of the T, . r''or example.
the most inteiae o.a-minute rainfi.:: .:,riod woul(I The intensity of rainfall. varies considerably during i,
contribul tL, the Leak discharge f; ,1 u-atershed storm as Well a. over gev,!rapnie regiuns. To
T �� ., rl;il tl:es: tll$> ],: ,st [n[e!1 C �.J Il+ltn' represe-L various regivn� h
of the United ates. SC'S
l�,e?'k,d wouid contribute to the peat; for a watershed developed four synthetic 24-hour rainfall (list r•ibut ion
s
with a 5-hour T, G. IA. 1I. and 111) from available National «eatl*r
Service '\1t'S) duration-frequency data iHer=llfield
Different rainfall (!I'tributi,)lns cat) be developed for 1961: Fi-ederick et al., 197..) or local stol'm datil.
Nach of tht ze waterzdle(is to emI)hasize the critical Type I.k is the least il)te])se all(I type 11 the most
rainfall duration for the peak dischare�s. However. intense short duration rainfall. The four distribution;
to avoid the ust• of iI diffel-erlt set of rainfall are shown in figure 13•1. and figrure B-2 shows their
intensitie= for each, drainage area size, a set of approximate geographic boundaries.
r1'llthe!iC rainfall having "nested-
1<iinf ell iu)€ensitit- was df-vt-lopl:1d. The s(•t Tvpe. I and ]1A represent the Pacifit' mill•itime
"rnaxinlizes- th, riiillfall intensities l-v incorporating clilnate With vet winters and dry summer,. T;.•l)e III
svlv reed ;l:net duration intensities +.:ti;in thoae repres(nts Gulf of Mexic„ and Atlantic coastal areas
??eed, 'i for li1nv(.1' dur;itl,ti11, at the si,n e probabilltl' where tropical storms brintr large 24-hi w- rainfall
level amounts. T\ )e 11 represents the rest of the c'ountr'\.
For more precise dist•ibutlon iloundal'u0s 11) it <ta(r
For the size of the drain wg- areiis : Which SCS having n'icire than one t1 iw. ('ontac the SCS `tatom
usuak. provides a-sistance, it str:r' "mod of 24 Conservation Engineer.
-u1-: was chosen for the synthetic rah if
it!]
di;ti-i'.)utions. Tht• 24-hour storm. while longer than
that needed t(, deterninc heal;: for thesp drainage
areas. is appr•oprizue for determining rig!soff volurnes-
Theyr, sint_rlo-• .:tome duration and a;�orlated
;.'rat} t't1C' raliltall fhrir'1t1t1iii;1'i van he us(-d to
?'l'l?1'e<e11I not uli:: UW Ileitis but also tht, '..
runoff voltlnl(" 1,„1 dr;dnagk, "We'l
-10-VI-TR•55. Second Ed- Jt,:lc 1u4761
.................................................................................... ................
Re n f a I I
Distribution
Typ
Type IA
Typ
Type III
ca
Alpi I I-lb I[I U4 t' g 1 4 lr t I 10 4 1 11 t N f, I I i t I I th'i I ibil I 1"It,
F] %./ (c f E:)
0 15 30 45 60 75 90 105 120 135 1 --)0 165
11.7 - i x
! x
11 . 8 - f x
I x
11. 9 - I x
x
12-. 0 - i x
! x
12-. 1 -- i x
x
12-. 2 - i x
i x t
12-.3 -- f x
i x
12-. 4 - x
I x
12-.5 - x
! S/
12-.7 - I x * a C O�vi�G-
I x {
12-. 8 -- I x
i x
12 .9 - ! x
x
13 0 - C x
i x *
13-.1
x
13-.2 -- i x
I x
13 .3 - I x
C x
13 . 4 - I x
x
13-. 5 - ! x
x
13•.6 - I x
I x
13 .7 - ! x
[ x ,
13-. 9 - I x
C
TIME
(hrs) * Hydrograph file ---> C :CLPS100 . HYD Qmax = 112. 0 cfs
x Hyd rograph file ---> C :CALPS10 . HYD Qmax - 7 8. 0 cf s
POND-2 Version: 3. 03 SIN: 87020533 01-01-1980 00 : 44 .13
DIVIDE ALL RESULTS BY TEN %�
Quick TR-55 Version : 3 . 41 SIN: 87010546
F1 (cfs)
0 15 30 45 60 75 90 105 120 135 1 -j0 165
l l-.7 - I x*
I x*
11. 8 - I x*
i x
11-. 9 - I x
1 x
12-.0 - I x
I x
12-.1 - J x
i x
12-.2 -- I x
I x
12•.3 - I x
12-.4 - J ZS r —�"� *� 0C r _
I x * OS
PO
12-.6 x
- I
I Clef 0 C orr t/Z-UL� x
12-.7 - I x
x
12-.8 -- I x
I x
12-.9 - I x
x
13-. 0 - I x
I x
13-.1 - I x
x
13-. 2 - I x
I x
13 3 - J x
I x
13 4 - J x
x
13-.5 - I x
I x
13-.6 - ( x*
! x
13-.7 - I x
x* Vr-� ` !
13 . 8 - J x*
I x*
13-. 9 - I x*
TIME
(hrs) * Hydrograph file ---> C :CLPS100 -. HYD Qmax = 112. 0 cfs
x Hydrograph file ----> C :CALPS25 -. HYD Qmax = 93 . 0 cfs
���'� DIVIDE ALL RESULTS BY TEN ��-
Quick TR-55 Version: 3. 41 SIN: 87010546
Flow (cfs)
0 15 30 45 60 75 90 105 120 135 165
!
11-.7
! x
x
x
11-. 9 - f x
! x
12.0 - I x
x
12.1 -- I x
x
12. 2 - I x
I x
12:3 - i 'x S x �
12.4 - I x * J�-
I x
12-.5 - I x
! x
12.6 - I x
I x n�
12-.7 -
12-.8 - I x
x
12.9 - ! x
x
13. 0 - I x
I x
x
I x
13.2 - ( x
! x
13.3 - f x
I x
13-. 4 - I x
I x
13.5 - I x
! x
13.6 - I x * }
! x * 5
13.7 - f x
I x
13-. 8 -- I x
I x
13. 9 - f x
I
TIME
(hrs) * Hydrograph file ---> C :CLPS100 HYD Qmax = 112-. 0 cfs
x Hydrograph file ---> C:CLPR100 -. hYD Qmax = 54. 0 cfs
DIVIDE ALL RESULTS BY TEN
Quick TR-55 Version: 3-. 41 SIN: 87010546
rl �w (cfs)
0. 0 8-. 0 16-. 0 24-.0 32-.0 40�. 0 48-. 0 56 . 0 64-. 0 72-. 0 86 . 0 88. 0
f
ll. 5 - I x
Ix
i1.6 -- Ix
Ix
ll-.7 - Ix
Ix
11. 8 - Ix
Ix
ll. 9 - Ix
Ix
12.0 - Ix
Ix
12.1 - I x
Ix --`
12. 2 - Ix
Ix
12.3 -- I x �y 1(�C�P4 r-
I x
12-. 4 - I x
I x
12.5 - I x
i x
12.6 - I x
x
12.7 - I x
i x
12.8 �-
*
12.9 I x
13.0 - I x
i x
13.1 - I x
I x
13. 2 - I x
I x
13.3 - I x
x
13. 4 - i x
I x * `
13.5 - I x
! x * /
13.6 - I x
I x
13-.7 - I x
I
TIME
Mrs) * Hydrograph file ---> C :CALPS10 . FYD Qmax = 78. 0 cfs
x Hydrograph file ----> C :CALPR10 . HYD Qmax = 24 . 0 cfs
Dt v EPE Acc