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Home My WebLink AboutTract Map 30767 Hydrology Study' 1 ' ' ' ' 1 ' ' ' ' ' ' 1 , ' 1 , ' RIVERSIDE COUNTY FLOOD CONTROL DISTRICT CITY OF TEMECULA TENTATIVE TRACT MAP 30767 HYDROLOGY STUDY January 2006 Prepared for. Ashby USA, LLC 470 E. Harrison Street Corona, CA 92879 Prepared by: Van Dell & Associates, Inc. \ ' ' , 1 ' , , 1 ' ' ' ' ' ' 1 , ' t ' TABLE OF CONTENTS i ~ ' ' C' ' ' INTRODUCTION Pianning Area 33A in Tentative Tract No. 30767, which is a component of Tract No. 29353, is a proposed single family residential subdivision located in the City of Temecula, Riverside County, California as shown in Vicinity Map, Figure 1. Tentative Tract No. 30767 contains 14 lots on approximately 10-acres. The proposed tract is bounded on the north by future Nicolas Road, on the south by San Gertrudis Creek Channel, on the west by 120-ft wide MWD Permanent Easements, and on the east by Butterfield Stage Road. The proposed tracts are situated on a rough graded pad within the Long Valley Wash of ' the Santa Gertrudis Creek watershed. In the existing condition, storm runoff generally sheet flows from northeast to southwest and collects in the existing Santa Gertrudis Creek. Additional hydrology information for the existing condition is contained in the , Drainage Study for the CFD and Village Core Portion of Roripaugh Ranch in the City of Temecula (Study), by David Evans & Associates, Inc., dated October 28, 2003. , The tributary area for the hydrology study for Tentative Tract No. 30767 includes all of the lots within the tract boundaries. The proposed condition will include the typical street sections sized to contain the 10-year runoff within the curbs and the 100-year flows ' within the street right-of-way. A portion of the eastern tract storm water runoff will be collected by two proposed catch basins near the intersection of Street "B" and Nicolas Road. ' This report contains the proposed developed condition hydrology study for the subdivisions. , 2. RATIONAL METHOD ANALYSIS ~ The Riverside County Flood Control and Water Conservation District Hydrology Manual, published in 1978, (Hydrology Manual) provided the guidelines and procedures for the 10- and 100-year Rational Method analyses. The parameters used for the rational ' method are summarized below. • Hydrologic boundaries were based on street grading pians for the subdivisions , as depicted on Figure 2, Hydrology Map, included in this report. • The underlying hydrologic soil group is Type B and C as shown on Plate C-1.53 of the Hydrology Manual. , • The rainfall depths used in the rational method analyses were based on those reported on Hydrology Manual Plates D-4.3 and D-4.4 for the 2-year, 1-hour and 100-year, 1-hour storm events, respectively. These values were used to , calculate the 1-hour rainfall intensity. The 10-year rainfall data was based on values derived from Plate D-4.5, and the slope of the intensity/duration curve was based on the information provided in Plate D-4.6. ' • The development density of Tentative Tract No. 30767 will be approximately 1.5 dwelling units per acre or approximately 20,000 square-feet per lot, which is assumed to be equivalent to single family residential with 40% impervious areas per Plate D-5.6. , ' X:NrqecM9W_0144~Eng\TechDOCSWeporis\TTM30767Hytlrdogyflepoh.tloc1 ~ ' , The rational method analysis was performed with software developed by CIVILDESIGN ' Corporation for both the 10- and 100-year storm events. The software was designed to accept watershed data and perform rational method analyses in accordance with the Hydrology Manual. The software defines subareas and routing paths by means of upstream and downstream node numbers, node elevation, travel distance, soil group, ' and type of conveyance. The Hydrology Map, Figure 2, shows the location of all node numbers used in the rational method analysis. ' 3. RESULTS The results of the Rational Method Hydrology Study are included in the Technical ' Appendices to this report. Table 3-1 below summarizes the peak discharges at each of the proposed catch basins. , Table 3-1 Rational Method Hydrology , Maximum 10-Year and 100-Year Storm Drai n Flow Rates Downstream Tributary Maximum Maximum Catch Basins Node Area 10-Year ~ 100-Year ~ ' Number (Ae) (cfs) (cfs) Catch Basin #1 22 3.82 4.59 7.59 Catch Basin #2 12 5.36 6.75 1126 ' Jundion Str. #1 10 920 10.91 18.06 ' r ~ ~ ~ ~~ ~ ~ ' X:NrojecLS~850_0144~Eng\TechOxs\Repotls\TTM 3016] Hytlmlogy Report.tlocr~ ~ G , ' 4. FIGURES ' Figure 1 - Vicinity Map ' Figure 2- Rational Method Hydrology Map , ' 1 , ' ' ' ' ' ' , , ' ' 1 XdPmjxts~B50_0144~En8~Tec~DOCSVieports\TTM 30]69 Hytlrology Report 0oc~ ~ 1 ~ ~ ~ ' ' , , ' , ~ ~ 1 1 1 ' , ' ' PROJECT SITE ~ ~ ~ ~ HOT SPRINCS Rp~p N~_~ ~P~ARY TM~ J ~ ACCE88 }}~ ~ ~/ ry~y/~~ cN~ ~ / ~ y~ 1 , y~ , G111GV1.1Y1 ( ~I~' ~ BB~DARY J I ~, ~ AC~88 ~~ W~~ ~ ~i m i~ ~„F~ i ~~ si ~i ~ ~ i ('/VyE r~i i c ~ ~FUPOS COHfEN10 fEN ~ ~ ~ NICNTY IIAAAP N.T.S. THOMAS BROTHERS MAP REFERENCE RIVERSIDE COUNTY 2001 EDITION PAGE 929, E-7 ~ -N- ~ ~° 5. TECHNICAL APPENDICES X:\ProjeM5~850_0144~EngUech~acsW epatls\TTM 30~6] Hytlrology fleport.tlocA ~ `t 1 ~ ' RIVERSIDE COUNTY HYDROLOGY MANUAL ' SOIL GROUP AND RAINFALL REFERENCE PLATES ' ' ' 1 , ' ' , 1 C' ' ' ' ' ' X?Pmjec~s~B50_0144~Eng\TechDOCSViepons\TTM30]6]APPND%CVRS.doc a ' ~ , ' ° 0 ' e c , ' B C ' E ' C E [ ' ' a C ' ~ B BC , A A B BC ' B i BC ' ' ' C B C , ' ' c ~ ~ ~ ;n 1.' 1 [ " ~ ,. ~ B-~ ~B An LEGEMD HYDROLOGIC SOILS GROUP MAP - SOIIS GROUP BOUNDARY . FOR A SOILS GROUP DESIGNATION - R C F C 8s W C D BACHELOR MTN. g NY4ROLOGY IYIANUAL O FEET 5000 ' ' 1 ' 1 , , ' ' ~r ' ' 1 , , , , ' ' , ~~ 3.5 3 3 ~ 2 5 = . 2.5 U Z Z 2 = H . 2 d W ~ J Q 1 9 . lL / 1.5 Z ~ / , /, / $ t ~ / / 5 - .5 0 0 2 5 10 25 50 100 RETURN PERIOD IN YEARS NOTE: I. For infermediate return ptrads pbt 2-year and 10p-yaar one hour volu~s from maps,fher~ conneet . points ond read value for desfred return per(od. For example qiven 2-yeor ona Aour=.50 ond 100- year one hour=I.60°,25-year one hour=l.l8~~ Referenee:NOAA Aflas 2,Volume~-California,l973. RAINFALL DEPTH VERSUS ~ R C FC & W C D RETURN PERIOD FOR p r~YDROLDGY 1~1~ANUAL PARTIAL DURATtON SERIES ` ~~ I~T~ h-w C 1 ' ' ' ~ 1 ' ' ' , ' ' ' 1 ' ' ' ' ~ ~ LOCATION 5 6 4 3 ~~I 7 5 4 3 2 5 , i~ 7 H H}} 5 4 3_ ~ IS 20 25 30 40 50 STORM DURATION-MINUTES RCFC a WCD r~Y~ROLOGY 1~/~ANUAL ~J I ~--I-1.7 -{-Ej.4 ~.~ 80 100 INTENSITY- DURATION CURVES `~ CI~LCULATION SHEET a1: ~ ~ ~ ~ o< >:> ~~W z N ~ z O Q U W ~ ~ W ~ < ~ 3 ~ j ;s = o_. = ~ I ~ e Q U ~ L~ W r ~ 0 0 P A ~~,' ~ . . ., j ~' ` ^~,~' . a \ 1 •~ ' _ ~ ~- jr L R Y _ - -' x~ . ... C:, _ ' ~ . . ;..t ~. ' _: ~ p. .. _ k~ ` .. . ~ ~, ..x_ n . - . ,3~ s ' ~a -, n y ~. : i . ~% q ~~ ~ - , ~ ~ e 0. OIp. ~ ~ e ..; pr .. B ~ ~ ' p ~ _ Q ?~.~ ~ ~~ ~ . ,Z;.~~ ~ ~ ~' /~ . Q ' _ / { '~ ~ ' ...=z . o SY~J -• ~ 'r ~F- U~ Z C ' ~, ~ f e e ~ ~~ i ~ ~ ~ 1 ~;. ~ ~~1~ K . ~ n M 'E R r ,`a ~. ~- • ,. <. . \ ~O. ~ F+ 4V . y - ~.. ~ . ~-. 11 11 ~ / r r . i € + ~I ~ O - ~ ' "~'• ~ f z ~~ , 1 ~ ~ .. . -_: i ~ . 7 ~ .% ~ - ~ ~'_Q -~ a . ,O ~. z .. LL. ' ` \ =~ '_ ' 0 1J' Y. ~ . •(~ lO' QE ~ ~ ~ ~~ f' a , ; ~ tSAi ^ f.' ~, i; ~. :'l~i F. 1 L ~-~:~;' ~ , ~ ;~ 9~ ; . i ;:, , = Y: r ~ < _ >~ a .~ " P ; o ?. , . . _ _ { ° '~ ` W ti ~ a:?- : . ' L _ -, ~ ~ o z ;0 F_ w , , ~ ~- _ o :V o~ C1 J~. ~ ~ e . ° ~n ' Q ~ ~ ~ ~ 1 9~ F ~~ `~ Q K L "'~ B~ ~ 0 i A 0 ~ - < . > 3 1 Z ~ ~ ~ ~ . ~~ i~ ~ ~ ~' ..'._c i . ~ n f ; .~ ( ' , i_ - .. . _ ~L . .7. ~ i _ 1 I.~k-F; .1-'/111 d t .9EC,f1 •• ' P ~ 1 L ' , ' ' , ' ' ' ~ ' ' , LJ ' ' ~ ^ ~ ACTUAL IMPERVIOIIS COVER Recommended Value Land Use (1) Range-Percent For Average Conditions-Percent(2 Natural or Agriculture 0- 10 0 Single Family Residential: (3) 40,000 S. F. (1 Acre) Lots 10 - 25 20 20,000 S. F. (~i Acre) Lots 30 - 45 40 f- 7,200 - 10,000 S> F. Lots 45 - 55 50 Multiple Family Residential: Condominiums 45 - 70 65 Apartznents 65 - 90 80 Mobile H~ae Park 60 - 85 75 Commercial, Downtown BO -100 90 Business or Industrial Notes: 1. Land use should be based on ultimate development of the watershed. Long range master plans for the County and incorporated cities should be reviewed to insure reasonable land use asswnptions. 2. Recommended values are based on average conditions which may not apply to a particular study area. The percentage impervious may vary greatly even on comparable sized lots due to differences in dwelling size, improvements, etc. Landscape practices,should also be considered as it is cormnon i.n some areas to use ornamental qrav- els underlain by impervious plastic materials in place of lawns and shrubs. A field i.nvestigation of a study area should alwaya be made, and a review of aerial photos, where available may assist in estima~ ing the percentage of impervious cover in developed areas. 3. For typical horse ranch subdivisions increase imperviws area 5 per- cent over the values reco~ended in the talile above. R C F C a W C D IMPERVIOUS COVER rJYDROLO~Y ~/~ANUAL ~~' R AREAS DEVELOPED c~ wrr n_c ' , ' FLOW SCHEMATIC ' & CIVILD PROGRAM OUTPUT (10-YR AND 100-YR ANALYSES) , , ' ~ ~ ' ' ' , , ' ~ ' , , KWrajects~B50_0144~Enp\TxhDOCS~Aeporis\TTM30]fi]APPNOXCVRS.tloc ,~o ~t~.l~iM~~d Q1-d2J ~9~~ '°~ Wll tt'~n~~w~L ~ o /s-~ ~~ Q ; ~ ~~~ r' ~ °v ~ W , ~ %.l .Q ~p ` ~ tl ~ ~ r 1r 4 ~ ~ i "1a W ~ ~ ~ , ~ - ~ ` v ~ N z~ ~ -- _' :~~ ,,~.N ~ ~ _ w ~ 9 CA W ~ 1~ O -tiP ~_ Q $~{ ~ 9 --s N ~ ~ p ~ ~y_ ~ I a D ~. ~ T ~ 1R N~ - ~ r - ~ ~ °~ W ~ C tn u ;~ ~~ - c 0 ~ ~ ~ a t' C,~ ~: .~ ~-^~O ~~ n~ ~N v ' ' AreaAlO.out Rivereide County Rational Hydrology Program ' CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4 Rational Hydrology Study Date: O1/03/06 File:AreaAlO.out _ _ _ _ _ _' _""' _"_ " """"" CITY OF TEMECULA -- TTM 30767 DEVELOPED CONDITION HYDROLOGY STUDY ' 10-YR 1-HR STORM .7AN ' 06 - A[tEA A ' '_______'__""__"'_______________"'_" " " " "________ *~+*~**•* Hydrology Study Control Information **w******* English (in-lb) ilnits used in input data file _'_________________________'_" " " "' " " "__ Van Dell and A990Ciatee, InC., Irvine, CA - S/N 953 "'_"__"_'_"'_________________'_'_" " " " " ' ______________________'"' Rational Method Hydrology Program based on Riverside County Flood Contxol & Water Conservation Diatrict 1978 hydrology manual ' Storm event (year) = 10.00 AnteCedent Moisture Condition = 2 2 year, 1 hour precipitation = 0.500(In.) 100 year, 1 hour precipitation = 1.180(In.) ' Storm event year = 10.0 Calculated xainfall inteneity data: 1 hour intensity = 0.780(In/Hr) ' Slope of intensity duration curve = 0.5600 1 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 26.000 to Point/Station 24.000 x**• INITIAL AREA EVALUATION +*** Initial area flow distance = 330.000(Ft.) , Top (of initial area) elevation = 1212.300(Ft.) Bottom (of initial area) elevation = 1207.400(Ft.) Difference in elevation = 4.900(Ft.) Slope = 0.01485 s(percent)= 1.48 TC = k(0.420)*[(length"3)/(elevation change)]"0.2 ~ Initial area time of concentration = 9.916 min. Rainfall intenaity = 2.137(In/Hr) for a 10.0 year storm SINGLE FAMILY (1/2 ACre Lot) Runoff Coefficient = 0.722 ' Decimal fraction soil group A= 0.000 Decimal fraction soil group H= 1.000 Decimal fraction soil group C= 0.000 Decimal fraction eoil group D= 0.000 RI index for soil(AMC 2) = 56.00 ' Pervious area fraction = 0.600; Impervious fraction = 0.400 Initial subarea runoff = 1.050(CFS) Total initial stream area = ~.680(AC.) Pervioue area fraction = 0.600 , ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Procesa from Point/Station 24.000 to Point/Station 22.000 **~* STREET FLOW TRAVEL TIMH + SUBAREA FIAW ADDITION •**• , Top of street segment elevation = 1207.9oo(Ft.) End of street segment elevation = 1204.200(Ft.) Length of atreet aegment = 669.000(Ft.) Height of curb above gutter flowline 6.0(In.) ' = Width of half street (curb to crown) 18.000(Ft.) Distance from crown to crosefall grade break 16.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street ' Page 1 ' 1~ 1 1 , ' ' ~ ' ' , 1 ' , AreaAlO.out Diatance from curb to property line = 5.500(Ft.) Slope from curb to property line (v/riz) = 0.020 Gutter width = 2.000(Ft.) . Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.473(CFS) Depth of flow = 0.393(Ft.), Average velocity = 1 .833(Ft/s) Streetflow hydraulics at midpoint of street travel: Half9treet flow width = 13.299(Ft.) Flow velocity = 1.83(Ft/s) Travel time = 6.~8 min. TC = 16.00 min. Adding area flow to etreet SINGLE FAMILY (1/2 Acre Lot) Runoff Coefficient = 0.690 Decimal fraction soil group A= 0.000 Decimal fraction soil group B= 0.990 Decimal fraction soil group C= 0.010 Decimal fraction soil group D= 0.000 RI index for soil(AMC 2) = 56.13 Pervious area fraction = 0.600; Impervious fraction = 0.400 Rainfall intensity = 1.635(In/Hr) for a 30.0 year storm Subarea runoff = 3.540(CFS) for 3.140(AC.) Total runoff = 4.590(CFS) Total area = 3 .820(AC.) Street flow at end of street = 4.590(CFS) Half street flow at end of street = 4.590(CFS) Depth of flow = 0.424(Ft.), Average velocity = 1 .959(Ft/s) Flow width (from curb towards crown)= 14.086(Ft.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PYOCeHe from POint/Station 22.000 to Point/Station 10.000 t**+ PIPEFLOW TRAVEL TIME (Program estimated size) +*** Upstream point/station elevation = 1200.200(Ft.) Downstream point/atation elevation = 1199.600(Ft.) Pipe length = 17.50(Ft.) Manning~s N= 0.013 No. of pipes = 1 Reguired pipe flow = 4.590(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 4.590(CFS) Normal flow depth in pipe = 7.37(In.) Flow top width inside pipe ~ 11.68(In.) Critical Depth = 10.72(In.) Pipe flOw velOCity = 9.08(Ft/8) Travel time through pipe = 0.03 min. Time of concentration (TC) = 16.03 min. , ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Proceae from Point/Station 10.000 to Point/Station 10.000 •*'• CONFLUENCE OF MINOR STREAMS •*~; Along Main Stream number: 1 in normal stream number 1 Stream flow area = 3.820(AC.) ' Runoff from this atream = 4.590(CFS) Time of concentration = 16.03 min. Rainfall intensity = 1.633(In/Hr) ' i+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Procese from Point/Station 16.000 to Point/Station 14.000 *+*~ INITIAL AREA EVALUATION •*** ' Initial area flow dietance = 241.000(Ft.) Top (of initial area) elevation = 1212.300(Ft.) Hottom (of initial area) elevation = 1207.400(Ft.) DiffeYenCe in elevation = 4.900(Ft.) ' Slope = 0.02033 s(percent)= 2.03 TC = k(0.420)*[(length"3)/(elevation change)]~0.2 Initial area time of concentration = 8.211 min. Rainfdll intensity = 2.375(In/Hr) fOY a 70.0 yeaY stoYm SINGLH FAMILY (1/2 Acre Lot) ' Runoff Coefficient = 0.735 Page 2 ' iq ' ' AreaAlO.out Decimal fraction soil group A= 0.000 Decimal fraction soil group B= 1.000 Decimal fraction soil group C= 0.000 ' Decimal fraction soil group D= 0.000 RI index for soil(AMC 2) = 56.00 Pervious area fraction = 0.600; Impervious fraction = 0.400 Initial subarea runoPf = 0.890(CFS) ' Total initial stream area = 0.510(AC.) Pervioue aYea fraction = 0.600 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ' * Process from Point/Station 14.000 to Point/Station 12.000 *** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION *«* Top of street segment elevation = 1207.400(Ft.) ERd Of stieet aegment elEVatiOn = 1204.200(Ft.) ' Length of street segment 733.500(Ft.) Height of curb above gutter flowline 6.o(in.) Width of half street (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020 ' Slope from grade break to crown (v/hz) 0.020 Street flow is on [1] aide(s) of the street Distance from curb to property line = 5.500(Ft.) Slope from curb to property line (v/hz) = 0.a20 Gutter width = 2.000(Ft.) , Gutter hike from flowline = 2.000(In.) Manning'e N in gutter = 0.0150 manning's N from gutter to grade break = 0.0150 Manning~s N from grade break to crown = 0.0150 ' Eetimated mean flow rate at midpoint of atreet = 5.139(CFS) Depth of flow = 0.444(Ft.), AveTage velocity = 1.944(Ft/s) StreetPlow hydraulics at midpoint of street travel: Halfstreet flow width = 15.862(Ft.) Flow velocity = 1.94(Ft/s) ' Travel time = 6.29 min. TC = 14.50 min. Adding area flow to street SINGLE FAMILY (1/2 ACYe Lot) Aunoff Coefficient = 0.696 Decimal fraction soil group A= 0.000 ' Decimal fraction soil group H= 1.000 Decimal fraction soil group C= 0.000 Decimal fraction eoil group D= 0.000 RI index for soil(AMC 2) = 56.00 Pervious area fraction = 0.600; Impervious fraction = 0.400 ' Rainfall intensity = 1.727(In/Hr) for a 10.0 year storm Subarea runoff = 5.856(CFS) for 4.870(AC.) Total runoff = 6.746(CFS) Total area = 5.380(AC.) ' Street flow at end of street = 6.746(CFS) FIalf atreet flow at end of street = 6.746(CFS) Depth of flow = 0.480(Ft.), Average veloCity = 2.077(Ft/s) Flow width (from curb towards crown)= 17.666(Ft.) 1 ++t+++++++++++++++++++++++++++++++++++++t+++++++++++++++++++++++++++++ Process from Point/Station 12.000 to Point/Station 10.000 +*** PIPEFLOW TRAVEL TIME (Program estimated size) +•** Upstream point/etation elevation = 12~0.2001Ft.) ' Downstream point/station elevation = 1199.600(Ft.) Pipe length = 30.30(Ft.) Manning's N= 0.013 No. of pipes = 1 Required pipe flow = 6.746(CFS) Nearest computed pipe diameter = 15.00(In.) - Calculated individual pipe flow 6.746(CFS) , Normal flow depth in pipe = 9.62(In.) Flow top width inside pipe = 14.39(In.) Critical Depth = 12.53(In.) Pipe flow velocity = e.ll(Ft/s) , Travel time through pipe = 0.06 min. Time of ConCentlation (TC) = 14.56 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++f+++++++++++++++++ ' Page 3 1 / , ' AreaAlO.out Process from Point/Station 10.000 to Point/Station 10.000 *~** WNFLUENCE OF MINOR STREAMS •*** ' Along Main Stream number: 1 in normal stream number 2 Stream flow area = 5.380(AC.) Runoff from this stream = 6.746(CFS) ' Time of concentration = 14.56 min. Rainfall intensity = 1.723(In/Hr) Summary of atream data: Stream Flow rate TC Rainfall Intensity ' No. (CFS) (min) (In/Hr) 1 4.590 16.03 1.633 2 6.746 14.56 1.723 Largeet stream flow has longer or shorter time of concentration ' Qp = 6.746 + sum of Qa Tb/Ta 4.590 * 0.908 = 4.169 4p = 10.915 ' Total of 2 streams to confluence: Flow rates before confluence point: 4.590 6.746 ' Area of streama before confluence: 3.820 5.380 Results of confluence: Total flow rate = 10.915(CFS) Time of concentration = 14.561 min. Effective stream area after confluence = 9.200(AC.) ' End of computations, total study area = 9.20 (AC.) The following figures may be used for a unit hydrograph study of the same area. Area averaged pervioue area fraction(Ap) = 0.600 ' Area averaged RI index number = 56.0 ' ' ' ~ ' ' ' ' Page 4 1 2\ AREAASOO.out Riveraide County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2001 Veision 6.4 Rational Hydrology Study Date: 01/03/O6 File:AREAAl00.out CITY OF TEMECULA -- TTM 30767 DEVELOPED CONDITION HYDROLOGY STUDY 100-YR 1-HR STORM JAN '06 - AREA A ***+***+* Hydrology Study Control Information •+*x•+...+ English (in-lb) Units used in input data file _""' ""'_" Van Dell and Associates, Inc., Irvine, CA - S/N 953 '_""""___""""""_"""" "'_" """"' Rational Method fiydrology Program based on Riverside County Flood Control & Water Conaervation Distiict 1978 hydrology manual Storm event (year) = 100.00 Antecedent Moisture Condition = 2 2 year, 1 hour precipitation = 0.500(In.) 700 year, 1 hour precipitation = 1.180(In.) Storm event year = 100.0 Calculated rainfall intensity data: 1 hour inteneity = 1.180(In/Hr) Slope of intenaity duration curve = 0.5600 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PYOCess fYOm Point/Station 26.000 to Point/StatiOn 24.000 t+*~ INITIAL AREA EVALUATION *•+' Initial area flow distance = 330.0~0(Ft.) Top (of initial area) elevation = 1212.300(Ft.) aottom (of initial area) elevation = 1207.400(Ft.) Difference in elevation = 4.900(Ft.) Slope = O.o1485 s(percent)= 1.48 TC = k(0.420)*((length"3)/(elevation change)]"0.2 Initial area time of concentration = 9.916 min. Rainfall intensity = 3.234(in/Hr) for a 700.0 year storm SINGLE FAMILY (1/2 Acre Lot) Runoff Coefficient = 0.768 Decimal fraction soil group A= 0.000 Decimal fraction soil group B= 1.000 Decimal £raction soil group C= 0.000 Decimal fraction aoil group D= 0.000 RI index for soil(AMC 2) = 56.00 Pervious area fraction = D.600; Impervioue fraction = 0.400 Initial subarea runoff = 1.689(CFS) Total initial stream area = 0.680(AC.) Pervious area fraction = 0.600 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 24.000 to Point/Station 22.000 **** STREET FLOW TRAVEL TIME + SUHAREA FLOW ADDITION •a** Top of street segment elevation = 1207.400(Ft.) End of street segment elevation = 1204.200(Ft.) Length of street segment = 669.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16.0o0(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] aide(s) of the street Page 1 ~ 1 ' AREAAl00.out Distance from curb to property line - 5.500(Ft.) Slope from cuzb to property line (v/hz) = 0.020 Gutter width = 2.000(Ft.) ' Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning~s N from gutter to grade break = 0.0150 htanning~s x from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 5.587(CFS) ' Depth of flow = 0.449(Ft.), Average velocity = 2.055(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 16.102(Ft.) Flow velocity = 2.05(Ft/s) ' Sravel time = 5.43 min. TC = 15.34 min. Adding area flow to street SINGLE FAMSLY (1/2 ACTE LOt) Runoff Coefficient = 0.743 Decimal fraction soil group A= 0.000 ' Decimal fraction soil group B= 0.990 Decimal fraction soil group C= 0.~10 Decimal fraction soil grossp D= 0.000 RS index for soil(AMC 2) = 56.13 Pervious area fraction = 0.600; Impervious fraction = 0.400 ' Rainfall intensity = 2.532(In/Hr) for a 100.0 year storm Subarea runoff = 5.905(CFS) for 3.140(AC.) Tota1 Yunoff = 7.593(CFS) TOtal aYea = 3.820(AC.) Street flow at end of atreet = 7.593(CFS) Half street flow at end of street = 7.593(CFS) ' Depth of flow = 0.489(Ft.), Average velocity = 2.222(Ft/s) Note: depth of flow exceeds top of street crown. Flow width (from curb towards crown)= 18.000(Ft.) ' ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PrOCese frOm Point/Station 22.000 to Point/Station 10.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) *•** ' Upstream point/station elevation = 1200.z00(Ft.) Downstream point/station elevation = 1199.600(Ft.) Pipe length = 17.50(Ft.) Manning's N= 0.013 No. of pipe9 = 1 RequiYed pipe flow = 7.593(CFS) Nearest computed pipe diameter = 15.00(In.) ' Calculated individual pipe flow = 7.593(CFS) Normal flow depth in pipe = 8.67(In.) Flow top width inside pipe = 14.82(In.) Critical Depth = 13.14(In.) Pipe flow velocity = 10.32(Ft/s) , Travel time through pipe = 0.03 min. Time of concentration (TC) = 15.37 min. 1 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Proceas from Point/Station 10.000 to Point/Station 10.000 •*** CONFLUENCE OF MINOR STREAMS ***~ Along Main Stream number: 1 in normal atream number 1 ' Stream flow area = 3.820(AC.) Aunoff £rom thie atream = 7.593(CFS) Time of concentration = 15.37 min. Rainfall intensity = 2.530(In/Hr) ' ' , ' ' +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++r++++++ Process from Point/Station 16.000 to Point/Station 14.000 ~*** INITIAI, AREA EVALOATION ***' Initial area flow distance = 241.000(Ft.) Top (of initial area) elevation = 1212.300(et.) Bottom (of initial area) elevation = 1207.400(Ft.) Difference in elevation = 4.900(Ft.) Slope = 0.02033 e(percent)= 2.03 TC = k(0.420)*[(length°3)/(elevation change)]"0.2 Initial area time of concentration = 8.211 min. Rainfall intensity = 3.594(In/Hr) for a 100.0 year storm SINGLE FAMILY (1/2 Acre Lot) Page ~ ' , Runoff Coefficient = 0.778 Decimal fraction soil group A= Decimal fraction soil group B= t Decimal fraction soil group C= Decimal fraction soil group D= RI index for soil(AMC 2) = 56. Pervious area fraction = 0. 600; Initial aubarea runoff = 1. ' Total initial 9tYeam aTea = Pervious area fraction = 0.600 ' ' , ' , ' ' i ' ' ' , ' ~ ~ AREAAl00.out 0.000 1.000 a.aoo 0.000 00 impervious 426(CFS) 0.510(AC fraction = ~.400 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PrOCees fZOm POint/StatiOn 14.000 to Point/Station 12.000 ~'•+* STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION *;** Top of street segment elevation = 1207.400(Ft.) End of street segment elevation = 1204.200(Ft.) Length of 6tYeet segment = 733.500(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half atreet (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16. 000(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] eide(s) of the street Distance from curb to property line = 5.500(Ft.) Slope from curb to property line (v/hz) = 0.020 GUtter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning~s N in gutter = 0.0150 Manning~s N from gutter to grade break = 0.0150 Manning~s N from grade break to crovm = 0.0150 Estimated mean flow rate at midpoint of street = 8.236(CFS) Depth of flow = 0.506(Ft.), Average velocity = a .219(Ft/s) warning: depth of flow exceeds top of curb Note: depth of flow exceede top of street crown. Distance that curb overflow reachea into property = 0.29(Ft.) Streetflow hydraulics at midpoint of atreet travel: Halfstreet flow width = 18.000(Ft.) FloW VeloCity = 2.22(Ft/e) Travel time = 5.51 min. TC = 13.72 min. Adding area flow to street SINGLE FAMILY (1/2 Acre Lot) Runoff Coefficient = 0.749 Decimal fraction soil group A= 0.000 Decimal fraction soil group H= 1.000 Decimal fraction soil group C= 0.000 Decimal fraction soil group D= 0.000 RI index for soil(AMC 2) = 56.00 Pervious area fraction = 0.600; Impervious fraction = 0.400 Rainfall intensity = 2.696(In/Hr) for a 100.0 year stonn Subarea runoYf = 9.832(CFS) for 9.870(AC.) Total runoff = 11.258(CFS) Total area = 5 .380(AC.) Street flow at end of gtreet = 11.258(CFS) Half street flow at end of atreet = 11.258(CFS) Depth of flow = 0.557(Ft.), Average velocity = 2 .389(Ft/s) Warning: depth of flow exceeds top of curb Note: depth of flow exceeds top of street crown. Dietance that curb overflow reachea into property = 2.85(Ft.) Flow width (from curb towards crown)= 18.000(Ft.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 12.000 to Point/Station 10.000 ~'** PIPEFLOW TRAVEL TIME (Program estimated eize) •**• Upstream point/atation elevation = 1200.200(Ft.) Downstream point/station elevation = 1199.600(Ft.) Pipe length = 30.30(Ft.) Manning's N= 0.013 No. of pipee = 1 Reqvired pipe flow = 11.258(CFS) Nearest computed pipe diameter = 18.00(In.) Calculated individual pipe flow = 11.258(CFS) Nonnal flow depth in pipe = 11.75(In.) Plow top width inside pipe = 77.14(In.) Page 2~ ' ' AREAaloo.out Critical Depth = 15.38(In.) Pipe flow velocity = 9.21(Ft/s) ' Travel time through pipe = 0.05 min. Time of concentration (TC) = 13.78 min. ++++++++++++++++~+++++++++++++++++++++++++++++++++++++++++++++++++.++. Process from Point/Station 70.000 to Point/Station 10.000 ' *a** CONFLUENCE OF MINOR STREAMS *t*• Along Main Stream number; 1 in noxmal stream number 2 ' Stream flow area = 5.380(AC.) Runoff from this stream = 11.258(CFS) Time of concentration = 13.78 min. Rainfall intensity = 2.690(In/Hr) Summary of stream data: ' Stream Flow rate TC Rainfall Intensity No. (CFS) (min) Qn/Hr) 1 7.593 15.37 2.530 ' 2 11.258 13.78 2.690 Largeet stream flow has longer or shorter time of concentration Qp = 11.258 + sum of Qa Tb/Ta 7.593 * 0.896 = 6.806 , Qp = 18.064 , ' J , ~ , , , ' Total of 2 streams to confluence: Flow rates before confluence point: 7.593 11.258 Area of etreams before confluence: 3.820 5.380 Resulta of confluence: Total flow rate = 18.064(CFS) Time of concentration = 13.776 min. sffective stream area after confluence = 9.200(AC.) End of computations, total study area = 9.20 (AC.) The following figures may be ueed for a unit hydrograph study of the same area. Area averaged pervious area fraction(Ap) = 0.600 Area averaged RI index number = 56.D ' Page 4 /. 2~