Loading...
HomeMy WebLinkAboutParcel Map 33488 Parcel 2 Hydrology ReportHYDROLOGY STUDY FOR PARCEL 2, PARCEL MAP 33488 PREPARED FOR: Mr. Fred Connary 30876 Lolita Rd. Temecula, Ca. 92592 • PREPARED BY: R.R.F. & Associates 22734 GIERSON AVE. WILDOMAR, CA. 92590 Tel: (951) 973-8076 DATE PREPARED: January , 2008 DATE REVISED: April, 2008 0 0 TABLE OF CONTENTS I. PROJECT DESCRIPTION IL RATIONAL METHOD INSTRUCTIONS 1. Instructions for Rational Method Hydrology Calculations 2. Hydrologic Soils Group Map III. HYDROLOGY CALCULATIONS A. PRE- DEVELOPED CONDITIONS 1.10 Year hydrology calculation 2.100 Year hydrology calculation A. POST- DEVELOPED CONDITIONS 1. 10 Year hydrology calculation • 2. 100 Year hydrology calculation IV. EXHIBITS 1. Hydrology map 0 I PROJECT DESCRIPTION E fe 0 I PROJECT DESCRIPTION This project is bounded by Santiago road on the north and Lolita road on the south. It is approximately 2.8 Ac. The owner intend to create an access opening along Santiago Road. A 20`driveway will be constructed of which will result in the blockage of the existing watercourse coming from the easterly boundary. A double 36" storm drain system will be constructed crossing this driveway. Hydrology analysis was based on the rational method of the Riverside County Flood Control District. The Discharge use on the easterly boundary was derived from the hydrology analysis prepared by BMB Tech Services. F- • II RATIONAL METHOD INSTRUCTIONS 0 •D 0 • C1 INSTRUCTIONS FOR RATIONAL METHOD HYDROLOGY CALCULATIONS (Based on the Rational Formula, Q = CIA) 1, on map of drainage area, draw drainage system and block off subareas tributary to it. 2. Determine the initial time of concentration, "T", using Plate D-3. The initial area should be less than 10 acres, have a flow path of less than 1,000 feet, and be the most upstream subarea. 3. Using the time of concentration, determine "I", intensity of rain- fall in inches per hour, from the appropriate intensity -duration curve for the particular area under study. For areas where stan- dard curves are available, use Plates D-4.1 and D-4.2 to reproduce the standard curve. For areas where curves have not been published by the District, use Plates D-4.3 through D-4.7 to develop a suit- able intensity -duration curve. 4. Determine "C", the coefficient of runoff, using the runoff coeffi- cient curve which corresponds as closely as possible with the soil, cover type and development of the drainage area. Standard curves (Plates D-5.1 through D-5.4) have been developed by the District for the common case of urban landscaping type cover. Where these curves are not applicable, curves may be developed using Plates D-5.5 through D-5.8. 5. Determine "A", the area of the subarea in acres. 6. Compute Q = CIA for the subarea. 7. Measure the length of flow to the point of inflow of the next sub- area downstream. Determine the velocity of flow in this reach for the peak Q in the type of conveyance being considered (natural channel, street, pipe, or open channel), using the tabling aids on Plates D-6 through D-9. Using the reach length and velocity determined above, compute the travel time, and add this time to the time of concentration for the previous subarea to determine a new time of concentration. B. Calculate Q for the new subarea, using steps 3 through 6 and the new time of concentration. Determine "Qp", the peak Q for all sub- areas tributary to the system to this point by adding Q for the new subarea to the summation of Q for all upstream subareas. Deter- mine the time of concentration for the next subarea downstream using Step 7. Continue tabling downstream in similar fashion until a junction with a lateral drain is reached. RCFC & WCD HYDROLOGY NIANUAL PLATE D-) U of 2) 7 10. Start at the upper end of the lateral and table its Q down to the junction with the main line, using the methods outlined in the previous steps. - Compute the peak Qat the junction. Let QA, TA, IA correspond to the tributary area with the longer time of concentration,and QB, TB, IB correspond to the tributary area with the shorter time of concentration and Qp, Tp correspond tolthe peak Q and time of concentration. I a. If the tributary areas have the same time of concentration, the tributary Q's are added directly to obtain the combined peak Q. Qp = QA + QB Tp I1= TA = TB b. If the tributary areas have different times of concentration, the smaller of the tributary Q's must be corrected as follows: (1) The usual case is where the tributary area with the lon- ger time of concentration has the larger Q. In this case, the smaller Q is corrected by la ratio of the intensities and added to the larger Q to obtain the combined peak Q. The tabling is then continued downstream using the longer time of concentration. Qp = QA + QB IA Tp TA IB i (2) In some cases, the tributary alea with the shorter time of concentration has the larger Q. In this case, the smaller Q is corrected by a ratio of the times of concen- tration and added to the larger Q to obtain the combined peak Q. The tabling is then continued downsteam using the shorter time of concentration_ Qp = QB + QA TB Tp p A RCFC 8► WCD r�YDRJLOGY JMANUAL TB RATIONAL METHOD INSTRUCTIONS PLATE D-1 (2 ofj2+1 1 RATIONAL METHOD General - The Rational method is commonly used for determining peak dis- charge from relatively small drainage areas. For areas in excess of 300 to 500 -acres the Synthetic Unit Hydrograph method should normally be used. Before attempting to apply the information in this section,the engineer should become thoroughly familiar with sections A, B and C of this manual. Rational Equation - The Rational method is based on the following equation: Q = CIA where: Q = Peak discharge - cfs C = Coefficient of runoff I = Rainfall intensity (inches/hour) corresponding to the time of concentration A = Area - acres Time of Concentration - If rain were to fall continously at a con- stant rate and be uniformly distributed over an impervious surface, the rate of runoff from that surface would reach a maximum rate equivalent to the rate of rainfall. This maximum would occur when all parts of the surface were contributing runoff to the concentration point. The time required to reach the maximum or equilibrium runoff rate is defined as the time of concentration. The time of concentration is a function of many variables including the length of the flow path from the most remote point of an area to the concentration point, the slope and other charac- teristics of natural and improved channels in the area, the infiltration characteristics of the soil, and the degree and type of development. In District Rational tabling, the time of concentration for an initial sub- area can be estimated from the nomograph on Plate D-3. The time of con- centration for the next downstream subarea is computed by adding to the D-1 initial time, the time required for the computed peak flow to travel to d the next concentration point. Time of is computed for each (concentration subsequent subarea by computing travel iti.me between subareas and adding r 3 the cumulative sum. Travel time may be',esti.mated using the tabling aids i on Plates D-6 through D-9. 1 To avoid distortion of travel time1large subareas should be avoided. a '• Where extremely large subareas are used, peak flow entering a travel reach may be much lower than the flow leaving1that reach. Velocity normally I 3 increases with discharge, therefore travel time computed using the average flow over a reach may be significantly lower than travel time computed � using inflow to the reach. Since rainfall intensity is inversely propor-... f i tional to time, flow rates would be consistantly underestimated by use N; :r; .Y•z of large subareas. C•: Intensity -Duration Curves - Rainfall intensity,."I", is determined k. •5 using District intensity -duration curves for the area under study. Stan- .e ; _ r J d dard intensity -duration curves have been prepared for many population centers in the District. Intensity -duration data for these standard curves 9' is given in tabular form on Plate D-4.1.1 The standard curves for these areas may be reproduced by plotting the 10 and 60 -minute values on Plate D-4.2, and drawing a straight line through them. For areas where curves have not been published, Plates D-4.3 through D-4.7 should be used to develop design intensity -duration curves!I. Plates D-4.3 and D-4.4 are isohyetal maps of the maximum 2 -year - ;��;'`_:• z 1 -hour and 100 -year - 1 -hour precipitation respectively. One-hour point rh'1 d rain for intermediate return periods can be determined from Plate D-4.5. _•.:= t_Y t2 The slope of the intensity duration curve can be obtained from Plate D-4.6; yy Intensity duration curves for a particular area can be easily developed''` `• Yv ��, i A • using Plate D-4.7, plotting the 1 -hour punt rain value for the desired t ID Ssa:S -2 }.• �i you ;t return period, and drawing a straight line through the 1 -hour value • parallel to the required slope. The isohyetal maps.and return period diagram are based on NOAA Atlas 2 discussed in more detail in Section B of this report. The map of intensity -duration curve slope is based on District analysis of all available recording rain gage records in and near the District. This material is also discussed in Section B of this manual. Coefficient of Runoff Curves - The coefficient of runoff is intended to account for the many factors which influence peak flow rate. The co- efficient depends on the rainfall intensity, soil type and cover, per- centage of impervious area, antecedent moisture condition, etc. To account for the difference between actual and effective impervious area it is assumed the maximum runoff rate which can occur from impervious surfaces is 90 -percent of the rainfall rate. The runoff from pervious surfaces is further reduced by infiltration. Runoff coefficient curves can be developed using the relationship: C = 0.9[Aii + I -Fp A { I FJI where: C = Runoff coefficient I = Rainfall intensity - inches/hour Fp = Infiltration rate for pervious areas - inches/hour' Ai = Impervious area (actual) - decimal percent A = Pervious area (actual) - decimal percent and A = 1.00 - A• P i The infiltration rate for pervious areas, "Fp", can be estimated using the methods discussed in Section C of this manual for various D-3 combinations of soil type, cover type and antecedent moisture condition • (AMC). In practice it is not necessary for the engineer to make these computations, as runoff coefficient curve data has been tabulated by the District on Plate D-5.7 for the working range of runoff index (RI) numbers. I Runoff coefficient curves can be developed for any combination of conditions by simply Plotting the data from Plate ID -5.7 on Plate D-5.8. In addition, for the common case of urban landscaping t e curves have been plotted on Plates D-5, • yp cover, runoff coefficient 1 through D-5.4. .,ew LEGEND HYDROLOGIC SOILS GROUP MAP SOILS GROUP BOUNDARY A SOILS GROUP DESIGNATION FOR R C F C 8i W C D PECHANGA HYDROLOGY NJA\NUAL p FEET 5000 PI ATF f.-1 FI i III HYDROLOGY CALCULATION A. PRE -DEVELOPED CONDITION 1. 10 YEAR HYDROLOGY STUDY 2. 100 YEAR HYDROLOGY STUDY B. POST - DEVELOPED CONDITION I. 10 YEAR HYDROLOGY STUDY . 2. 100 YEAR HYDROLOGY STUDY • • RIVERSIDE COUNTY RATIONAL HYDROLOGY PROGRAM CIVILCADD/CIVILDESIGN ENGINEERING SOFTWARE, (C) 1989 - 2004 VERSION 7.0 RATIONAL HYDROLOGY STUDY DATE: 06/05/08 FILE: NODE22 PRE I OCONNARY. OUT ------------------------------------------------------------------------ PCL 2-PM33488 10 YEAR PRE -DEVELOPED CONDITION FN:NODE22PRE1000NNARY C:CIVIL\RF\CONNARY ------------------------------------------------------------------------ ********* HYDROLOGY STUDY CONTROL INFORMATION ********** ENGLISH (IN -LB) UNITS USED IN INPUT DATA FILE ------------------------------------------------------------------------ PROGRAM LICENSE SERIAL NUMBER 4066 ------------------------------------------------------------------------ RATIONAL METHOD HYDROLOGY PROGRAM BASED ON RIVERSIDE COUNTY FLOOD CONTROL & WATER CONSERVATION DISTRICT 1976 HYDROLOGY MANUAL STORM EVENT (YEAR) = 10.00 ANTECEDENT MOISTURE CONDITION = 2 STANDARD INTENSITY -DURATION CURVES DATA (PLATE D-4.1) • FOR THE [ MURRIETA,TMC,RNCH CANORCO I AREA USED. 10 YEAR STORM lO MINUTE INTENSITY = 2.360(IN/HR) 10 YEAR STORM 60 MINUTE INTENSITY = 0.880(IN/HR) 100 YEAR STORM 10 MINUTE INTENSITY = 3.480(It7/HR) 100 YEAR STORM 60 MINUTE INTENSITY = 1.300(IN/HR) STORM EVENT YEAR = 10.0 CALCULATED RAINFALL INTENSITY DATA: 1 HOUR INTENSITY = 0.880(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 12.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 359. 000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1268. 000 (FT. BOTTOM (OF INITIAL AREA) ELEVATION = 1242.000(FT.) DIFFERENCE IN ELEVATION = 26.000(FT.) SLOPE = 0.07242 S(PERCENT)= 7.24 TC = K(0.390)*[(LENGTH^3)/(ELEVATION CHANGE) )^0.2 INITIAL AREA TIME OF CONCENTRATION = 6.936 MIN. • RAINFALL INTENSITY = 2.883(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.802 DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 INITIAL SUBAREA RUNOFF = 6.083(CFS) TOTAL INITIAL STREAM AREA = 2.630(AC.) PERVIOUS AREA FRACTION = 0.500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 12.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 2.630(AC.) RUNOFF FROM THIS STREAM = 6.083(CPS) TIME OF CONCENTRATION = 6.94 MIN. RAINFALL INTENSITY = 2.883(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 ++++++++++++++++++++++++++++++++t++++++++++++++++++++++++++}}+++++++++ PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 12.000 **** INITIAL AREA EVALUATION **** • INITIAL AREA FLOW DISTANCE = 500.000 (FT. ) TOP (OF INITIAL AREA) ELEVATION = 1302.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1242.000(FT.) DIFFERENCE IN ELEVATION = 60.000(FT.) SLOPE = 0.12000 S(PERCENT)= 12.00 TC = K(0.480)*[(LENGTH�3)/(ELEVATION CHANGE)J�0.2 INITIAL AREA TIME OF CONCENTRATION = 8.610 MIN. RAINFALL INTENSITY = 2.528 (IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.727 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 INITIAL SUBAREA RUNOFF = 8.434(CFS) TOTAL INITIAL STREAM AREA = 4.590(AT.) PERVIOUS AREA FRACTION = 0.600 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 12.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: • IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 4.590(AC.) RUNOFF FROM THIS STREAM = 8.434(CFS) TIME OF CONCENTRATION = 8.81 MIN. • RAINFALL INTENSITY = 2.528(IN/HR) SUMMARY OF STREAM DATA: STREAM FLOW RATE TC RAINFALL INTENSITY No. (CFS) (MIN) (IN/HR) 1 6.083 6.94 2.883 2 8.434 8.81 2.528 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 8.434 + SUM OF QB IA/IB 6.083 * 0.877 = 5.333 QP = 13.767 TOTAL OF 2 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 6.083 8.434 AREA OF STREAMS BEFORE CONFLUENCE: 2.630 4.590 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 13.767(CFS) TIME OF CONCENTRATION = 8.810 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 7.220(AC.) PROCESS FROM POINT/STATION 12.000 TO POINT/STATION 12.100 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1242.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1225.000(FT.) LENGTH OF NATURAL CHANNEL = 800.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 26.161(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS)^. 352) (SLOPE^O . 5) VELOCITY USING MEAN CHANNEL FLOW = 4.70(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0213 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0213 TRAVEL TIME = 2.84 MIN. TO = 11.65 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.779 DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 • PERVIOUS AREA FRACTION = 0.500: IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 2.168(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 21.946(CFS) FOR 13.000(Ac.) TOTAL RUNOFF = 35.713(CFS) TOTAL AREA = 20.220(Ac • PROCESS FROM POINT/STATION 12.100 TO POINT/STATION 13.000 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) **** UPSTREAM POINT/STATION ELEVATION = 1225. 000(FT.) DOWNSTREAM POINT/STATION ELEVATION = 1220.000(FT.) PIPE LENGTH = 122.00(FT.) MANNING'S N = 0.015 No. OF PIPES = 1 REQUIRED PIPE FLOW = 35.713(CFS) NEAREST COMPUTED PIPE DIAMETER = 24.00 (IN.) CALCULATED INDIVIDUAL PIPE FLOW = 35.713(CFS) NORMAL FLOW DEPTH IN PIPE = 17.79(IN.) FLOW TOP WIDTH INSIDE PIPE = 21.02(IN.) CRITICAL DEPTH COULD NOT BE CALCULATED. PIPE FLOW VELOCITY = 14.30(FT/S) TRAVEL TIME THROUGH PIPE = 0.14 MIN. TIME OF CONCENTRATION (TC) = 11.79 MIN. +.++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1220.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1195.000(FT.) LENGTH OF NATURAL CHANNEL = 1130.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 43.890(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS)^.352)(SLOPE^0.5) VELOCITY USING MEAN CHANNEL FLOW = 5.55(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0221 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0221 TRAVEL TIME = 3.40 MIN. TC = 15.19 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.765 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL(AMC 2) = 62.50 • PERVIOUS AREA FRACTION = 0.5001 IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 1.874(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 13.278(CFS) FOR 9.260(Ac.) • TOTAL RUNOFF = 48.991 (CFS) TOTAL AREA = 29.480 (AC. ) PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 14.100 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) **** UPSTREAM POINT/STATION ELEVATION = 1195.000(FT. ) DOWNSTREAM POINT/STATION ELEVATION = 1192.000(FT.) PIPE LENGTH = 192.00(FT.) MANNING'S N = 0.013 N0. OF PIPES = 2 REQUIRED PIPE FLOW = 48.991(CFS) NEAREST COMPUTED PIPE DIAMETER = 24.00 (IN.) CALCULATED INDIVIDUAL PIPE FLOW = 24.496(CFS) NORMAL FLOW DEPTH IN PIPE = 17.25(IN.) FLOW TOP WIDTH INSIDE PIPE = 21.58(IN.) CRITICAL DEPTH = 20.98(IN.) PIPE FLOW VELOCITY = 10.13(FT/S) TRAVEL TIME THROUGH PIPE = 0.32 MIN. TIME OF CONCENTRATION (TC) = 15.50 MIN. PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 14.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: I STREAM FLOW AREA = 29.480(AC.) • RUNOFF FROM THIS STREAM = 48.991 (CFS) TIME OF CONCENTRATION = 15.50 MIN. RAINFALL INTENSITY = 1.853(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 PROCESS FROM POINT/STATION 1%.000 TO POINT/STATION 18.000 **** INITIAL AREA EVALUATION **** INITIAL AREA. FLOW DISTANCE = 932.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1281.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 126".000(FT.) DIFFERENCE IN ELEVATION = 19.000(FT.) SLOPE = 0.02039 S(PERCENT)= 2.04 TC = R(O.4BO)*[(LENGTH^3)/(ELEVATION CHANGE) )"0.2 INITIAL AREA TIME OF CONCENTRATION = 16.112 MIN. RAINFALL INTENSITY = 1.814(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.680 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 • INITIAL SUBAREA RUNOFF = 0.937(CFS) TOTAL INITIAL STREAM AREA = 0.760(AC.) PERVIOUS AREA FRACTION = 0.800 PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 19.100 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 19.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 9.260(AD.) RUNOFF FROM THIS STREAM = 11.368(CFS) • TIME OF CONCENTRATION = 19.52 MIN. RAINFALL INTENSITY = 1.632(IN/HR) SUMMARY OF STREAM DATA: TOP OF STREET SEGMENT ELEVATION = 1262.000(FT.) END OF STREET SEGMENT ELEVATION = 1192.000(FT.) LENGTH OF STREET SEGMENT = 1190.000 (FT. ) HEIGHT OF CURB ABOVE GUTTER FLOWLINE = 6.0(IN. ) WIDTH OF HALF STREET (CURB TO CROWN) = 20.000(FT.) DISTANCE FROM CROWN TO CROSSFALL GRADE BREAK = 18.000(FT.) SLOPE FROM GUTTER TO GRADE BREAK (V/HZ) = 0.069 SLOPE FROM GRADE BREAK TO CROWN (V/HZ) = 0.020 STREET FLOW IS ON [1) SIDES) OF THE STREET DISTANCE FROM CURB TO PROPERTY LINE = 10.000(FT.J 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'B 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 = 6.175(CFS) DEPTH OF FLOW = 0.325(FT.), AVERAGE VELOCITY = 5.574(FT/S) STREETFLOW HYDRAULICS AT MIDPOINT OF STREET TRAVEL: HALFSTREET FLOW WIDTH = 9.905(FT.) FLOW VELOCITY = 5. 57(FT/S) TRAVEL TIME = 3.91 MIN. TO = 19.52 MIN. • ADDING AREA FLOW TO STREET SINGLE FAMILY (1/9 ACRE LOT) RUNOFF COEFFICIENT = 0.752 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 1.632(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 10.931(CFS) FOR 8.500(AC.) TOTAL RUNOFF = 11.368(CFS) TOTAL AREA = 9.260 (AC STREET FLOW AT END OF STREET = 11.368(CFS) HALF STREET FLOW AT END OF STREET — 11.368(CFS) DEPTH OF FLOW = 0. 383(FT.), AVERAGE VELOCITY = 6.426(FT/S) FLOW WIDTH (FROM CURB TOWARDS CROWN)— 12.815(FT.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 19.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 9.260(AD.) RUNOFF FROM THIS STREAM = 11.368(CFS) • TIME OF CONCENTRATION = 19.52 MIN. RAINFALL INTENSITY = 1.632(IN/HR) SUMMARY OF STREAM DATA: • STREAM FLOW RATE TC RAINFALL INTENSITY NO. (CFS) (MIN) (IN/HR) 1 48.991 15.50 1.853 2 11.366 19.52 1.632 LARGEST STREAM FLOW HAS LONGER OR SHORTER TIME OF CONCENTRATION QP = 48.991 + sum OF QA TB/TA 11.368 * 0.794 = 9.027 QP = 58.018 TOTAL OF 2 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 48.991 11.368 AREA OF STREAMS BEFORE CONFLUENCE: 29.480 9.260 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 58.018(CFS) TIME OF CONCENTRATION = 15.501 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 38.740(AC.) CHECK OF PREVIOUS CONFLUENCE OPERATIONS ---- OF ALL MAIN STREAMS • TOTAL OF 4 STREAMS TO CONFLUENCE: FLOW RATES BEFORE AND MAXIMUM AFTER CONFLUENCE POINT: NO. FLOW RATE TC I MAX CONFLUENCE 1 6.083 13.627 1.989 52.399 2 8.434 15.501 1.853 58.352 3 11.368 19.520 1.632 54.819 4 35.225 15.501 1.853 58.352 NOTE: LAST STREAM IS AREA ADDED BETWEEN CONFLUENCES RESULTS OF CONFLUENCE CHECK TOTAL FLOW RATE = 58.352(CFS) TIME OF CONCENTRATION = 15.501 MIN. NOTE: MAXIMUM FLOW RATE DERIVED FROM PREVIOUS CONFLUENCES = 56. 35 (CFS) THIS EXCEEDS NORMAL CONFLUENCE RATE OF 58.02(CFS) THEREFORE, LARGEST CONFLUENCE FLOW RATE AND TC = 15.50 MIN. IS USED. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 14.100 TO POINT/STATION 21.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1192.000(FT.) • END OF NATURAL CHANNEL ELEVATION = 1173.000(FT.) LENGTH OF NATURAL CHANNEL = 575.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 66.335 (CFS) • NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS)^. 352)(SLOPE^ 0. 5) VELOCITY USING MEAN CHANNEL FLOW = 7.64(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0330 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0330 TRAVEL TIME = 1.25 MIN. TC = 16.76 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/9 ACRE LOT) RUNOFF COEFFICIENT = 0.760 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 1.775(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 14.302(CPS) FOR 10.600(AC.) TOTAL RUNOFF = 72.659 (CFS) TOTAL AREA = 99.390 (AC ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ • PROCESS FROM POINT/STATION 19.100 TO POINT/STATION 21.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 99.390(AC.) RUNOFF FROM THIS STREAM = 72.659(CFS) TIME OF CONCENTRATION = 16.76 MIN. RAINFALL INTENSITY = 1.775(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 20.000 TO POINT/STATION 21.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 583. OOO (FT. ) TOP (OF INITIAL AREA) ELEVATION = 1273.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1173.000(FT.) DIFFERENCE IN ELEVATION = 100.000(FT.) SLOPE = 0.17153 S(PERCENT)= 17.15 TC = K(0.980)*[(LENGTH�3)/(ELEVATION CHANGE)]^0.2 INITIAL AREA TIME OF CONCENTRATION = 8.723 MIN. RAINFALL INTENSITY = 2.542(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.728 • DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 • RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 INITIAL SUBAREA RUNOFF = 6. 843 (CPS) TOTAL INITIAL STREAM AREA = 3.700(Ac.) PERVIOUS AREA FRACTION = 0.800 PROCESS FROM POINT/STATION 20.000 TO POINT/STATION 21.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 3.700(Ac.) RUNOFF FROM THIS STREAM = 6.843(CFS) TIME OF CONCENTRATION = 6.72 MIN. RAINFALL INTENSITY = 2.5542(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 +++++++++++++++++t+++-F.+++..+++++t+++++++++++++++++++++++++..+++++t+++ PROCESS FROM POINT/STATION 21.000 TO POINT/STATION 22.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1173.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1152.500(FT.) LENGTH OF NATURAL CHANNEL = 520.000(FT.) • ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 0.000(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) _ (7 + 8(Q(ENGLISH UNITS)^. 352) (SLOPE^O . 5) VELOCITY USING MEAN CHANNEL FLOW = 1.39(FT/S) • CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0394 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0394 TRAVEL TIME = 6.24 MIN. TC = 14.96 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.686 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 1.889(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 10.365(CFS) FOR 8.000(Ac.) TOTAL RUNOFF = 10.365(CFS) TOTAL AREA = 11.700(Ac ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ • PROCESS FROM POINT/STATION 21.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 11.700(AC.) RUNOFF FROM THIS STREAM = 10.365(CFS) TIME OF CONCENTRATION = 14.96 MIN. RAINFALL INTENSITY = 1.889(IN/HR) PROGRAM IS HOW STARTING WITH MAIN STREAM N0. 2 PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 22.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1194.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1152.500(FT.) LENGTH OF NATURAL CHANNEL = 520.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 0.000(CPS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (% + 8(O(ENGLISH UNITS)".352)(SLOPE^0.5) VELOCITY USING MEAN CHANNEL FLOW = 1.98(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) • NORMAL CHANNEL SLOPE = 0.0798 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0798 TRAVEL TIME = 4.38 MIN. TC = 19.34 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.752 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 1. 640(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 9.380(CFS) FOR 7. 600(AC.) TOTAL RUNOFF = 9.380(CFS) TOTAL AREA = 19.300(Ac ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 19.300(AC.) • RUNOFF FROM THIS STREAM = 9.380(CFS) TIME OF CONCENTRATION = 19.34 MIN. RAINFALL INTENSITY = 1.640(IN/HR) PROGRAM I5 NOW STARTING WITH MAIN STREAM NO. 3 • PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 16.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 1000. 000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1194.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1162.000(FT.) DIFFERENCE IN ELEVATION = 32.000(FT.) SLOPE = 0.03200 S(PERCENT)= 3.20 TC = K(0.390)*[(LENGTH A 3)/(ELEVATION CHANGE) ]"0.2 INITIAL AREA TIME OF CONCENTRATION = 12.304 MIN. RAINFALL INTENSITY = 2.104(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.776 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2 ) = 62.50 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 INITIAL SUBAREA RUNOFF = 16.324 (CFS) TOTAL INITIAL STREAM AREA = 10.000(AC.) PERVIOUS AREA FRACTION = 0.500 PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 16.000 **** CONFLUENCE OF MINOR STREAMS **** ALONG MAIN STREAM NUMBER: 3 IN NORMAL STREAM NUMBER I STREAM FLOW AREA = 10.000(AC.) RUNOFF FROM THIS STREAM = 16.324(CFS) TIME OF CONCENTRATION = 12.30 MIN. RAINFALL INTENSITY = 2.104(IN/HR) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 15.000 TO POINT/STATION 16.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 428.000 (FT. ) TOP (OF INITIAL AREA) ELEVATION = 1204.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1162.000(FT.) DIFFERENCE IN ELEVATION = 42.000(FT.) SLOPE = 0.09813 5(PERCENT)= 9.81 TC = K (0 . 390) * [ (LENGTH"3) / (ELEVATION CHANGE) ]^0.2 INITIAL AREA TIME OF CONCENTRATION = 7.003 MIN. RAINFALL INTENSITY = 2.868(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.802 DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2 ) • PERVIOUS AREA FRACTION = 0 INITIAL SUBAREA RUNOFF = TOTAL INITIAL STREAM AREA = PERVIOUS AREA FRACTION = 0. • = 62.50 .500; IMPERVIOUS FRACTION = 0.500 7.635(CPS) 3.320(Ac.) 500 ++++++++++++++++t+....+++++t+++++.+++++++++++++++f+++++++-h++++++++t+++ PROCESS FROM POINT/STATION 15.000 TO POINT/STATION 16.000 **** CONFLUENCE OF MINOR STREAMS **** ALONG MAIN STREAM NUMBER: STREAM FLOW AREA = 3 RUNOFF FROM THIS STREAM = TIME OF CONCENTRATION = RAINFALL INTENSITY = SUMMARY OF STREAM DATA: 3 IN NORMAL STREAM NUMBER 2 320(Ac.) 7.635(CPS) 7.00 MIN. .868(IN/HR) STREAM FLOW RATE TC RAINFALL INTENSITY N0. (CFS) (MIN) (IN/HR) 1 16.324 12.30 2.104 2 7.635 7.00 2.868 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 16.324 + SUM OF QB IA/IB 7.635 * 0.733 = 5.600 QP = 21.923 TOTAL OF 2 STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 16.324 7.635 AREA OF STREAMS BEFORE CONFLUENCE: 10.000 3.320 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 21.923(CFS) TIME OF CONCENTRATION = 12.309 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 13.320(AC.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 16.000 TO POINT/STATION 22.000 **** IMPROVED CHANNEL TRAVEL TIME **** UPSTREAM POINT ELEVATION = 1162.000 (FT. ) DOWNSTREAM POINT ELEVATION = 1152.500(FT.) CHANNEL LENGTH THRU SUBAREA = 85.000(FT.) CHANNEL BASE WIDTH = 0.000(FT.) SLOPE OR 'Z' OF LEFT CHANNEL BANK = 10.000 SLOPE OR 'Z' OF RIGHT CHANNEL BANK = 10.000 MANNING'S 'N' = 0.015 MAXIMUM DEPTH OF CHANNEL = 0.500(FT. ) FLOW (Q) THRU SUBAREA = 21.923(CFS) DEPTH OF FLOW = 0.430(FT.)I AVERAGE VELOCITY = 11.849(FT/S) CHANNEL FLOW TOP WIDTH = 8.603(FT.) FLOW VELOCITY = 11.85(FT/S) ++++++++++++++++++.......++++++i -+++++++.++.+++++++++++++-h .+++=+-F+t-F... PROCESS FROM POINT/STATION 16.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: 114 MAIN STREAM NUMBER: 3 STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 21.923(CFS) TIME OF CONCENTRATION = 12.42 MIN. RAINFALL INTENSITY = 2.092(IN/HR) SUMMARY OF STREAM DATA: STREAM TRAVEL TIME = 0. 12 MIN. RAINFALL INTENSITY • TIME OF CONCENTRATION = 12.42 MIN. (MIN) (IN/HR) SUB -CHANNEL NO. 1 CRITICAL DEPTH = 0.781(FT.) 1.889 2 CRITICAL FLOW TOP WIDTH = 10.000(FT.) 1.640 ' r ' CRITICAL FLOW VELOCITY= 4.127(FT/S) 2.092 ' r ' CRITICAL FLOW AREA = 5.313(SQ.FT) ++++++++++++++++++.......++++++i -+++++++.++.+++++++++++++-h .+++=+-F+t-F... PROCESS FROM POINT/STATION 16.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: 114 MAIN STREAM NUMBER: 3 STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 21.923(CFS) TIME OF CONCENTRATION = 12.42 MIN. RAINFALL INTENSITY = 2.092(IN/HR) SUMMARY OF STREAM DATA: STREAM FLOW RATE TC RAINFALL INTENSITY NO. (CFS) (MIN) (IN/HR) 1 10.365 14.96 1.889 2 9.380 19.34 1.640 • 3 21.923 12.42 2.092 LARGEST STREAM FLOW HAS LONGER OR SHORTER TIME OF CONCENTRATION QP = 21.923 + SUM OF QA TB/TA 10.365 * 0.831 = 8.609 QA TB/TA 9.380 * 0.642 = 6.025 QP = 36.557 TOTAL OF 3 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 10.365 9.380 21.923 AREA OF STREAMS BEFORE CONFLUENCE: 11.700 19.300 13.320 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 36.557(CFS) TIME OF CONCENTRATION = 12.423 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 44.320(AC.) --- CHECK OF PREVIOUS CONFLUENCE OPERATIONS ------ OF ALL MAIN STREAMS TOTAL OF 6 STREAMS TO CONFLUENCE: • FLOW RATES BEFORE AND MAXIMUM AFTER CONFLUENCE POINT: NO. FLOW RATE TC I MAX CONFLUENCE 1 6.083 13.084 2.034 RUNOFF COEFFICIENT = 0.683 79.762 2 8.434 14.958 1.889 DECIMAL FRACTION SOIL GROUP C = 0.500 85.319 • 3 11.368 18.977 1.657 PERVIOUS AREA FRACTION = 0.800; 81.198 = 0.200 4 35.225 10.0 YEAR STORM 14.958 FOR 4 .4 1.889 TOTAL RUNOFF = 90.917(CFS) 85.319 = 48.750 (AC 5 9.380 THE FOLLOWING FIGURES MAY 19.341 1.640 OF THE SAME 80.626 6 21.923 12.423 2.092 77.426 RESULTS OF CONFLUENCE CHECK TOTAL FLOW RATE = 85.319(CFS) TIME OF CONCENTRATION = 14.958 MIN. NOTE: MAXIMUM FLOW RATE DERIVED FROM PREVIOUS CONFLUENCES = 85.32 (CFS) THIS EXCEEDS NORMAL CONFLUENCE RATE OF 36.56(CFS) THEREFORE, LARGEST CONFLUENCE FLOW RATE AND TC = 14.96 MIN. IS USED. ++++++++++++-F++++++++++++++++++++++++-F++++++++++t++++++++++.+++....+++ PROCESS FROM POINT/STATION 22.000 TO POINT/STATION 23.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHAN14EL ELEVATION = 1152.500(FT.) END OF NATURAL CHANNEL ELEVATION = 1134.500(FT.) LENGTH OF NATURAL CHANNEL = 354.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 89.583(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: • VELOCITY(FT/S) _ (7 + 8(Q(ENGLISH UNITS )A.352)(SLOPE^0.5) VELOCITY USING MEAN CHANNEL FLOW = 10.36(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0508 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0508 TRAVEL TIME = 0.57 MIN. TC = 15.53 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.683 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX. FOR SOIL (AMC 2 ) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 1.851(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 5.597 (CFS) FOR 4 .4 30 (AC. ) TOTAL RUNOFF = 90.917(CFS) TOTAL AREA = 48.750 (AC END OF COMPUTATIONS, TOTAL STUDY AREA = 86.39 (AC.) THE FOLLOWING FIGURES MAY BE USED FOR A UNIT HYDROGRAPH STUDY OF THE SAME AREA. • AREA AVERAGED PERVIOUS AREA FRACTION(AP) = 0.575 AREA AVERAGED RI INDEX NUMBER = 62.5 • RIVERSIDE COUNTY RATIONAL HYDROLOGY PROGRAM CIVILCADD/CIVILDESIGN ENGINEERING SOFTWARE, (C) 1989 - 2004 VERSION 7.0 RATIONAL HYDROLOGY STUDY DATE: 06/05/08 FILE: NODE22 PRE I OOCONNARY. OUT ------------------------------------------------------------------------ PCL 2 - PM 33488 100 YEAR PRE -DEVELOPED CONDITION FN: NODE22PRE10000NNARY C:CIVIL\RF\CONNARY ------------------------------------------------------------------------ HYDROLOGY STUDY CONTROL INFORMATION ********** ENGLISH (IN -LB) UNITS USED IN INPUT DATA FILE ------------------------------------------------------------------------ PROGRAM LICENSE SERIAL NUMBER 4066 ------------------------------------------------------------------------ RATIONAL METHOD HYDROLOGY PROGRAM BASED ON RIVERSIDE COUNTY FLOOD CONTROL & WATER CONSERVATION DISTRICT 1978 HYDROLOGY MANUAL STORM EVENT (YEAR) = 100.00 ANTECEDENT MOISTURE CONDITION = 3 STORM EVENT YEAR = 100.0 CALCULATED RAINFALL INTENSITY DATA: 1 HOUR INTENSITY = 1.300(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 12.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 359.000 (FT. ) TOP (OF INITIAL AREA) ELEVATION = 1268. 000 (FT. BOTTOM (OF INITIAL AREA) ELEVATION = 1242.000(FT.) DIFFERENCE IN ELEVATION = 26.000(FT.) SLOPE = 0.07242 S(PERCENT)= 7.24 TC = K(0.390) * [ (LENGTH'3) / (ELEVATION CHANGE) ] ^0.2 INITIAL AREA TIME OF CONCENTRATION = 6.936 MIN. • RAINFALL INTENSITY = 4.259(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.867 STANDARD INTENSITY -DURATION CURVES DATA (PLATE D-4.1) • FOR THE [ MURRIETA,TMC,RNCH CANORCO ) AREA USED. 10 YEAR STORM 10 MINUTE INTENSITY = 2.360(IN/HR) 10 YEAR STORM 60 MINUTE INTENSITY = 0.880(IN/HR) 100 YEAR STORM 10 MINUTE INTENSITY = 3.480(IN/HR) 100 YEAR STORM 60 MINUTE INTENSITY = 1.300(IN/HR) STORM EVENT YEAR = 100.0 CALCULATED RAINFALL INTENSITY DATA: 1 HOUR INTENSITY = 1.300(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 12.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 359.000 (FT. ) TOP (OF INITIAL AREA) ELEVATION = 1268. 000 (FT. BOTTOM (OF INITIAL AREA) ELEVATION = 1242.000(FT.) DIFFERENCE IN ELEVATION = 26.000(FT.) SLOPE = 0.07242 S(PERCENT)= 7.24 TC = K(0.390) * [ (LENGTH'3) / (ELEVATION CHANGE) ] ^0.2 INITIAL AREA TIME OF CONCENTRATION = 6.936 MIN. • RAINFALL INTENSITY = 4.259(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.867 DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 INITIAL SUBAREA RUNOFF = 9.715(CPS) TOTAL INITIAL STREAM AREA = 2.630(AC.) PERVIOUS AREA FRACTION = 0.500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 12.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 2.630(AC.) RUNOFF FROM THIS STREAM = 9.715(CPS) TIME OF CONCENTRATION = 6.94 MIN. RAINFALL INTENSITY = 4.259(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 12.000 **** INITIAL AREA EVALUATION **** • INITIAL AREA FLOW DISTANCE = 500.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1302.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1242.000(FT.) DIFFERENCE IN ELEVATION = 60.000(FT.) SLOPE = 0.12000 S(PERCENT)= 12.00 TC = K(0.480)*[(LENGTH^3) /(ELEVATION CHANGE)]^0.2 INITIAL AREA TIME OF CONCENTRATION = 6.810 MIN. RAINFALL INTENSITY = 3. 734(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.841 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 INITIAL SUBAREA RUNOFF = 14.414(CFS) TOTAL INITIAL STREAM AREA = 4.590(AC.) PERVIOUS AREA FRACTION = 0.800 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 12.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: • IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 4.590(AC.) RUNOFF FROM THIS STREAM = 14.414(CFS) TIME OF CONCENTRATION = 8.81 MIN. • RAINFALL INTENSITY = 3.734 (IN/HR) SUMMARY OF STREAM DATA: STREAM FLOW RATE TO RAINFALL INTENSITY N0. (CFS) (MIN) (IN/HR) 1 9.715 6.94 4.259 2 14.414 8.81 3.734 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 14.414 + SUM OF QB IA/IB 9.715 * 0.877 = 8.518 QP = 22.932 TOTAL OF 2 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 9.715 14.414 AREA OF STREAMS BEFORE CONFLUENCE: 2.630 4.590 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 22.932(CFS) TIME OF CONCENTRATION = 8.810 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 7.220(AC.) PROCESS FROM POINT/STATION 12.000 TO POINT/STATION 12.100 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1242.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1225.000(FT.) LENGTH OF NATURAL CHANNEL = 800.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 43.577 (CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) ^.352)(SLOPE^0.5) VELOCITY USING MEAN CHANNEL FLOW = 5.42 (FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0213 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0213 TRAVEL TIME = 2.46 MIN. TC = 11.27 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FA14ILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.858 DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX. FOR SOIL (AMC 3) = 80.00 • PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 3.261(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 36.389(CFS) FOR 13.000(Ac.) TOTAL RUNOFF = 59.320(CFS) TOTAL AREA = 20.220 (AC 0 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 12.100 TO POINT/STATION 13.000 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) **** UPSTREAM POINT/STATION ELEVATION = 1225. 000(FT.) DOWNSTREAM POINT/STATION ELEVATION = 1220.000(FT.) PIPE LENGTH = 122.00(FT.) MANNING'$ N = 0.015 No. OF PIPES = 1 REQUIRED PIPE FLOW = 59.320(CFS) NEAREST COMPUTED PIPE DIAMETER = 30.00(IN.) CALCULATED INDIVIDUAL PIPE FLOW = 59.320(CFS) NORMAL FLOW DEPTH IN PIPE = 20.77(IN.) FLOW TOP WIDTH INSIDE PIPE = 27.70(IN.) CRITICAL DEPTH COULD NOT BE CALCULATED. PIPE FLOW VELOCITY = 16.38(FT/S) TRAVEL TIME THROUGH PIPE = 0.12 MIN. TIME OF CONCENTRATION (TC) = 11.39 MIN. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1220.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1195.000(FT.) LENGTH OF NATURAL CHANNEL = 1130.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 72.909 (CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) ^. 352) (SLOPE^0 . 5) VELOCITY USING MEAN CHANNEL FLOW = 6.43(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0221 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0221 TRAVEL TIME = 2.93 MIN. TC = 14.32 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.853 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 • PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 2.858(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 22.577(CPS) FOR 9.260(Ac.) TOTAL RUNOFF = 81.897(CFS) TOTAL AREA = 29.480(AC.) ++++++++++++++++++..............++++++++++++++++++++ff++++++++++++++++ PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 14.100 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) **** UPSTREAM POINT/STATION ELEVATION = 1195.000 (FT.) DOWNSTREAM POINT/STATION ELEVATION = 1192.000(FT.) PIPE LENGTH = 192.00(FT.) MANNING'S N = 0.013 NO. OF PIPES = 2 REQUIRED PIPE FLOW = 81.897(CFS) NEAREST COMPUTED PIPE DIAMETER = 27.00(IN.) CALCULATED INDIVIDUAL PIPE FLOW = 40.949(CFS) NORMAL FLOW DEPTH IN PIPE = 23.91(IN.) FLOW TOP WIDTH INSIDE PIPE = 17.20(IN.) CRITICAL DEPTH = 25.25(IN.) PIPE FLOW VELOCITY = 11.00(FT/S) TRAVEL TIME THROUGH PIPE = 0.29 MIN. TIME OF CONCENTRATION (TC) = 14.61 MIN. PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 14.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 29.480(AC.) • RUNOFF FROM THIS STREAM = 81.897(CFS) TIME OF CONCENTRATION = 14.61 MIN. RAINFALL INTENSITY = 2.827(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 PROCESS FROM POINT/STATION 17.000 TO POINT/STATION 18.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 932.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1281.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1262. 000 (FT. DIFFERENCE IN ELEVATION = 19.000(FT.) SLOPE = 0.02039 S(PERCENT)= 2.04 TC = K ( 0.480) * [ (LENGTH^3) /(ELEVATION CHANGE) ] ^0.2 INITIAL AREA TIME OF CONCENTRATION = 16.112 MIN. RAINFALL INTENSITY = 2. 679(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.820 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 • INITIAL SUBAREA RUNOFF = I.670(CPS) TOTAL INITIAL STREAM AREA - 0.760(AC.) PERVIOUS AREA FRACTION = 0.800 PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 14.100 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 14.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 9.260(AC.) RUNOFF FROM THIS STREAM = 19.199(CFS) • TIME OF CONCENTRATION = 19.13 MIN. RAINFALL INTENSITY = 2.438(IN/HR) SUMMARY OF STREAM DATA: TOP OF STREET SEGMENT ELEVATION = 1262.000(FT.) END OF STREET SEGMENT ELEVATION = 1192.000(FT.) LENGTH OF STREET SEGMENT = 1140. 000 (FT.) HEIGHT OF CURB ABOVE GUTTER FLOWLINE = 6.0(IN.) WIDTH OF HALF STREET (CURB TO CROWN) = 20.000(FT.) DISTANCE FROM CROWN TO CROSSFALL GRADE BREAK = 18.000(FT. ) SLOPE FROM GUTTER TO GRADE BREAK (V/HZ) = 0.064 SLOPE FROM GRADE BREAK TO CROWN (V/HZ) = 0.020 STREET FLOW IS ON [1] SIDES) OF THE STREET DISTANCE FROM CURB TO PROPERTY LINE = 10.000(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 CROWN = 0.0150 ESTIMATED MEAN FLOW RATE AT MIDPOINT OF STREET = 10.473(CFS) DEPTH OF FLOW = 0.374(FT.), AVERAGE VELOCITY = 6.303(FT/S) STREETFLOW HYDRAULICS AT MIDPOINT OF STREET TRAVEL: HALFSTREET FLOW WIDTH = 12.389(FT.) FLOW VELOCITY = 6.30(FT/5) TRAVEL TIME = 3.01 MIN. TC = 19.13 MIN. • ADDING AREA FLOW TO STREET SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.846 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 2.438(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 17.529(CFS) FOR 8.500(AC.) TOTAL RUNOFF = 19.199(CFS) TOTAL AREA = 9.260(AC. STREET FLOW AT END OF STREET = 19.199(CFS) HALF STREET FLOW AT END OF STREET = 19.199(CFS) DEPTH OF FLOW = 0.443(FT.), AVERAGE VELOCITY = 7.287(FT/S) FLOW WIDTH (FROM CURB TOWARDS CROWN)= 15.837(FT. ) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 18.000 TO POINT/STATION 14.100 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 9.260(AC.) RUNOFF FROM THIS STREAM = 19.199(CFS) • TIME OF CONCENTRATION = 19.13 MIN. RAINFALL INTENSITY = 2.438(IN/HR) SUMMARY OF STREAM DATA: • STREAM FLOW RATE TC RAINFALL INTENSITY No. (CFS) (MIN) (IN/HR) 1 81.897 14.61 2.827 2 19.199 19.13 2.438 LARGEST STREAM FLOW HAS LONGER OR SHORTER TIME OF CONCENTRATION QP = 81.897 + SUM OF QA TB/TA 19.199 * 0.764 = 14.670 QP = 96.567 TOTAL OF 2 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 81.897 19.199 AREA OF STREAMS BEFORE CONFLUENCE: 29.480 9.260 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 96.567(CFS) TIME OF CONCENTRATION = 14.614 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 38.740(AC.) RESULTS OF CONFLUENCE CHECK TOTAL FLOW RATE = 97.058(CFS) TIME OF CONCENTRATION = 14.614 MIN. NOTE: MAXIMUM FLOW RATE DERIVED FROM PREVIOUS CONFLUENCES = 97.06(CFS) THIS EXCEEDS NORMAL CONFLUENCE RATE OF 96.57(CFS) THEREFORE, LARGEST CONFLUENCE FLOW RATE AND TC = 14.61 MIN. IS USED. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 14.100 TO POINT/STATION 21.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1192.000(FT.) • END OF NATURAL CHANNEL ELEVATION = 1173.000(FT.) LENGTH OF NATURAL CHANNEL = 575.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 110.337 (CFS) -------------- CHECK OF PREVIOUS CONFLUENCE OPERATIONS ------------- OF ALL MAIN STREAMS • TOTAL OF 4 STREAMS TO CONFLUENCE: FLOW RATES BEFORE AND MAXIMUM AFTER CONFLUENCE POINT: No. FLOW RATE TC I MAX CONFLUENCE 1 9.715 12.740 3.048 86.474 2 14.414 14.614 2.827 97.058 3 19.199 19.126 2.438 90.255 4 58.965 14.614 2.827 97.058 NOTE: LAST STREAM IS AREA ADDED BETWEEN CONFLUENCES RESULTS OF CONFLUENCE CHECK TOTAL FLOW RATE = 97.058(CFS) TIME OF CONCENTRATION = 14.614 MIN. NOTE: MAXIMUM FLOW RATE DERIVED FROM PREVIOUS CONFLUENCES = 97.06(CFS) THIS EXCEEDS NORMAL CONFLUENCE RATE OF 96.57(CFS) THEREFORE, LARGEST CONFLUENCE FLOW RATE AND TC = 14.61 MIN. IS USED. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 14.100 TO POINT/STATION 21.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1192.000(FT.) • END OF NATURAL CHANNEL ELEVATION = 1173.000(FT.) LENGTH OF NATURAL CHANNEL = 575.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 110.337 (CFS) • NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) ^. 352) (SLOPE^O . 5) VELOCITY USING MEAN CHANNEL FLOW = 8.89(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0330 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0330 TRAVEL TIME = 1.08 MIN. TC = 15.69 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.851 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 2.718(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 24.516(CFS) FOR 10.600(AC.) TOTAL RUNOFF = 121.574 (CFS) TOTAL AREA = 49.340(AC ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ • PROCESS FROM POINT/STATION 14.100 TO POINT/STATION 21.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 49.340(AC.) RUNOFF FROM THIS STREAM = 121.574(CFS) TIME OF CONCENTRATION = 15.69 MIN. RAINFALL INTENSITY = 2.718 (IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 20.000 TO POINT/STATION 21.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 583.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1273.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1173.000(FT.) DIFFERENCE IN ELEVATION = 100.000(FT.) SLOPE = 0.17153 S(PERCENT)= 17.15 TC = K(0.480) * [ (LENGTH^3) / (ELEVATION CHANGE) ] ^0.2 INITIAL AREA TIME OF CONCENTRATION = 8.723 MIN. RAINFALL INTENSITY = 3.755(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.841 • DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 • RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 INITIAL SUBAREA RUNOFF = 11.688 (CFS) TOTAL INITIAL STREAM AREA = 3.700(AC.) PERVIOUS AREA FRACTION = 0.800 +++++++++++++++++++++++++++++++++++++++++++++++-h++++++++++++++++++++++ PROCESS FROM POINT/STATION 20.000 TO POINT/STATION 21.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 3.700(AC.) RUNOFF FROM THIS STREAM = 11.688(CFS) TIME OF CONCENTRATION = 8.72 MIN. RAINFALL INTENSITY = 3.755(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 21.000 TO POINT/STATION 22.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1173.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1152.500(FT.) LENGTH OF NATURAL CHANNEL = 520.000(FT.) • ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 0.000(CPS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) ^. 352)(SLOPE^O.5) VELOCITY USING MEAN CHANNEL FLOW = 1.39(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0394 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0394 TRAVEL TIME = 6.24 MIN. TO = 14.96 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.823 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 2.791(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 18.379(CFS) FOR 8.000(AC.) TOTAL RUNOFF = 18.379 (CFS) TOTAL AREA = 11.700 (AC • +++++++++++++++++++++++++++++++++++-F++++++++++++++++++++++++++++++++++ • PROCESS FROM POINT/STATION 21.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: I STREAM FLOW AREA = 11.700(AC.) RUNOFF FROM THIS STREAM = 18.379(CFS) TIME OF CONCENTRATION = 14.96 MIN. RAINFALL INTENSITY = 2.791(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM N0. 2 ++++++++++++++++++++++."f'+++++++++++++++++'f'"F".+'f'+++++++++++++++T++++++++ PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 22.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1194.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1152.500(FT.) LENGTH OF NATURAL CHANNEL = 520.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 0.000(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) ^. 352) (SLOPE^O . 5) VELOCITY USING MEAN CHANNEL FLOW = 1. 98(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) • NORMAL CHANNEL SLOPE = 0.079E CORRECTED/ADJUSTED CHANNEL SLOPE = 0.079E TRAVEL TIME = 4.38 MIN. TC = 19.34 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.846 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX, FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 RAINFALL INTENSITY = 2.423(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 15.572(CFS) FOR 7. 600 (AD. TOTAL RUNOFF = 15.572 (CFS) TOTAL AREA = 19.300 (Ac ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 19.300(AC.) • RUNOFF FROM THIS STREAM = 15.572(CFS) TIME OF CONCENTRATION = 19.34 MIN. RAINFALL INTENSITY = 2.423 (IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM N0. 3 PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 16.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 1000.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1194.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1162.000(FT.) DIFFERENCE IN ELEVATION = 32.000(FT.) SLOPE = 0.03200 S(PERCENT)= 3.20 TO = R(0.390)*[(LENGTH�3)/(ELEVATION CHANGE) J^0.2 INITIAL AREA TIME OF CONCENTRATION = 12.304 MIN. RAINFALL INTENSITY = 3.107 (IN/BR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.856 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 INITIAL SUBAREA RUNOFF = 26.613(CFS) TOTAL INITIAL STREAM AREA = 10.000(AC.) PERVIOUS AREA FRACTION = 0.500 PROCESS FROM POINT/STATION 19.000 TO POINT/STATION 16.000 **** CONFLUENCE OF MINOR STREAMS **** ALONG MAIN STREAM NUMBER; 3 IN NORMAL STREAM NUMBER 1 STREAM FLOW AREA = 10.000(AC.) RUNOFF FROM THIS STREAM = 26.613(CFS) TIME OF CONCENTRATION = 12.30 MIN. RAINFALL INTENSITY = 3.107(IN/HR) PROCESS FROI4 POINT/STATION 15.000 TO POINT/STATION 16.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 428.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1204.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1162.000(FT.) DIFFERENCE IN ELEVATION = 42.000(FT.) SLOPE = 0.09813 S(PERCENT)= 9.81 TC = E(0.390)*[(LENGTH"3)/(ELEVATION CHANGE) ]"0.2. INITIAL AREA TIME OF CONCENTRATION = 7.003 MIN. RAINFALL INTENSITY = 4.237 (IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1/4 ACRE LOT) RUNOFF COEFFICIENT = 0.86% DECIMAL FRACTION SOIL GROUP A = 0.000 • DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 • PERVIOUS AREA FRACTION = 0.500; IMPERVIOUS FRACTION = 0.500 INITIAL SUBAREA RUNOFF = 12.197(CFS) TOTAL INITIAL STREAM AREA = 3.320(AC.) PERVIOUS AREA FRACTION = 0.500 • +++++++tt.++++++++i-+++.++++....+i-++++++.+++++++++f++++++++++++++++++++ PROCESS FROM. POINT/STATION 15.000 TO POINT/STATION 16.000 **** CONFLUENCE OF MINOR STREAMS **** ALONG MAIN STREAM NUMBER: STREAM FLOW AREA = 3 RUNOFF FROM THIS STREAM = TIME OF CONCENTRATION = RAINFALL INTENSITY = SUMMARY OF STREAM DATA: 3 IN NORMAL STREAM NUMBER 2 320(Ac.) 12.197(CFS) 7.00 MIN. .237(IN/HR) STREAM FLOW RATE TC RAINFALL INTENSITY No. (CFS) (MIN) (IN/HR) 1 26.613 12.30 3.107 2 12.197 7.00 9.237 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 26.613 + SUM OF QB IA/IB 12.197 * 0.733 = 8.997 QP = 35.559 TOTAL OF 2 STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 26.613 12.197 AREA OF STREAMS BEFORE CONFLUENCE: 10.000 3.320 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 35.559(CFS) TIME OF CONCENTRATION = 12.309 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 13.320(AC.) PROCESS FROM POINT/STATION 16.000 TO POINT/STATION 22.000 **** IMPROVED CHANNEL TRAVEL TIME **** UPSTREAM POINT ELEVATION = 1162. 000(FT.) DOWNSTREAM POINT ELEVATION = 1152. 500 (FT. ) CHANNEL LENGTH THEN SUBAREA = 85.000(FT.) CHANNEL BASE WIDTH = 0.000(FT.) SLOPE OR 'Z' OF LEFT CHANNEL BANK = 10.000 SLOPE OR 'Z' OF RIGHT CHANNEL BANK = 10.000 MANNING'S 'N' = 0.015 MAXIMUM DEPTH OF CHANNEL = 0.500(FT.) FLOW(Q) THRU SUBAREA = 35.5S9(CFS) • DEPTH OF FLOW = 0.513(FT.), AVERAGE VELOCITY = 13.538(FT/S) !!WARNING: WATER IS ABOVE LEFT OR RIGHT BANK ELEVATIONS CHANNEL FLOW TOP WIDTH = 10.000(FT.) FLOW VELOCITY = 13.54(FT/S) • TRAVEL TIME = 0.10 MIN. TIME OF CONCENTRATION = 12.41 MIN. SUB—CHANNEL NO. 1 CRITICAL DEPTH = 0.984(FT.) CRITICAL FLOW TOP WIDTH = 10.000(FT CRITICAL FLOW VELOCITY= 4.842(FT/S) CRITICAL FLOW AREA = 7.344(SQ.FT) ERROR - CHANNEL DEPTH EXCEEDS MAXIMUM ALLOWABLE DEPTH ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 16.000 TO POINT/STATION 22.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 3 STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 35.559(CFS) TIME OF CONCENTRATION = 12.41 MIN. RAINFALL INTENSITY = 3.093(IN/HR) SUMMARY OF STREAM DATA: STREAM FLOW RATE TC RAINFALL INTENSITY NO. (CFS) (MIN) (IN/FIR) • 1 18.379 14.96 2.791 2 15.572 19.34 2.423 3 35.559 12.41 3.093 LARGEST STREAM FLOW HAS LONGER OR SHORTER TIME OF CONCENTRATION QP = 35.559 + sum of QA TB/TA 18.379 * 0.830 = 15.246 QA TB/TA 15.572 * 0.642 = 9.990 QP = 60.796 TOTAL OF 3 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 18.379 15.572 35.559 AREA OF STREAMS BEFORE CONFLUENCE: 11.700 19.300 13.320 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 60.796(CFS) TIME OF CONCENTRATION = 12.408 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 44.320(AC.) -------------- CHECK OF PREVIOUS CONFLUENCE OPERATIONS -------- OF ALL MAIN STREAMS • TOTAL OF 6 STREAMS TO CONFLUENCE: FLOW RATES BEFORE AND MAXIMUM AFTER CONFLUENCE POINT: NO. FLOW RATE TC I MAX CONFLUENCE . 1 9.715 13.084 3.004 131.874 2 14.414 DECIMAL FRACTION SOIL GROUP C = 0.500 14.958 2.791 DECIMAL FRACTION SOIL GROUP D = 0.000 141.284 3 19.199 19.470 2.414 = 0.200 133.752 4 58.965 14.958 2.791 141.284 5 15.572 END OF COMPUTATIONS, TOTAL STUDY AREA = 86.39 19.341 2.423 THE FOLLOWING FIGURES MAY 134.045 6 35.559 12.408 3.093 127.869 RESULTS OF CONFLUENCE CHECK: TOTAL FLOW RATE = 141.284(CFS) TIME OF CONCENTRATION = 14.958 MIN. NOTE: MAXIMUM FLOW RATE DERIVED FROM PREVIOUS CONFLUENCES = 141.28 (CFS) THIS EXCEEDS NORMAL CONFLUENCE RATE OF 60.80(CFS) THEREFORE, LARGEST CONFLUENCE FLOW RATE AND TC = 14.96 MIN. IS USED. PROCESS FROM POINT/STATION 22.000 TO POINT/STATION 23.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1152.500(FT.) END OF NATURAL CHANNEL ELEVATION = 1134.500(FT.) LENGTH OF NATURAL CHANNEL = 354.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 148.345 (CFS) • NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS) '. 352)(SLOPE^O. 5) VELOCITY USING MEAN CHANNEL FLOW = 12.06(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0508 CORRECTED/ADJUSTED CHANNEL SLOPE = 0.0508 TRAVEL TIME = 0.49 MIN. TC = 15.45 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.822 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL(AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 2.742 (IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 9. 984 (CFS) FOR 4 .4 30 (Ac. ) TOTAL RUNOFF = 151.268(CFS) TOTAL AREA = 48.750(Ac END OF COMPUTATIONS, TOTAL STUDY AREA = 86.39 (AC.) THE FOLLOWING FIGURES MAY • BE USED FOR A UNIT HYDROGRAPH STUDY OF THE SAME AREA. AREA AVERAGED PERVIOUS AREA FRACTION(AP) = 0.575 AREA AVERAGED RI INDEX NUMBER = 62.5 11 Ll 0 RIVERSIDE COUNTY RATIONAL HYDROLOGY PROGRAM • CIVILCADD/CIVILDESIGN ENGINEERING SOFTWARE, (C) 1989 - 2009 VERSION 7.0 RATIONAL HYDROLOGY STUDY DATE: 06/05/08 FILE: POST 10. OUT ------------------------------------------------------------------------ PCL 2 - PM 33988 10 YEAR POST DEVELOPED CONDITION FN:POST10 C: \CIVILD\RF\CONNARY ------------------------------------------------------------------------ ********* HYDROLOGY STUDY CONTROL INFORMATION ********** ENGLISH (IN -LB) UNITS USED IN INPUT DATA FILE PROGRAM LICENSE SERIAL NUMBER 9066 ------------------------------------------------------------------------ RATIONAL METHOD HYDROLOGY PROGRAM BASED ON RIVERSIDE COUNTY FLOOD CONTROL & WATER CONSERVATION DISTRICT 1978 HYDROLOGY MANUAL STORM EVENT (YEAR) = 10.00 ANTECEDENT MOISTURE CONDITION = 2 STANDARD INTENSITY -DURATION CURVES DATA (PLATE D-9.1) STORM EVENT YEAR = 10.0 CALCULATED RAINFALL INTENSITY DATA: I HOUR INTENSITY = 0.880(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 10.000 **** USER DEFINED FLOW INFORMATION AT A POINT **** RAINFALL INTENSITY = 1.889(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.686 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL(AMC 2) = 62.50 • PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: FOR THE [ MURRIETA, TMC, RNCH CANORCO ] AREA USED. • 10 YEAR STORM 10 MINUTE INTENSITY = 2.360(IN/HR) 10 YEAR STORM 60 MINUTE INTENSITY = 0.880(IN/HR) 100 YEAR STORM 10 MINUTE INTENSITY = 3.980(IN/HR) 100 YEAR STORM 60 MINUTE INTENSITY = 1.300(IN/HR) STORM EVENT YEAR = 10.0 CALCULATED RAINFALL INTENSITY DATA: I HOUR INTENSITY = 0.880(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 10.000 **** USER DEFINED FLOW INFORMATION AT A POINT **** RAINFALL INTENSITY = 1.889(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.686 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL(AMC 2) = 62.50 • PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: • TC = 14.96 MIN. RAIN INTENSITY = 1.89(IN/HR) TOTAL AREA = 81.96 (AC. ) TOTAL RUNOFF = 85.32 (CFS) PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 14.000 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) **** UPSTREAM POINT/STATION ELEVATION = 1152.500(FT.) DOWNSTREAM POINT/STATION ELEVATION = 1151.000(FT.) PIPE LENGTH = 38.00(FT.) MANNING'S N = 0.013 No. of PIPES = 2 REQUIRED PIPE FLOW = 85.320(CFS) NEAREST COMPUTED PIPE DIAMETER = 24.00(IN.) CALCULATED INDIVIDUAL PIPE FLOW = 42.660(CFS) NORMAL FLOW DEPTH IN PIPE = 18.66(IN.) FLOW TOP WIDTH INSIDE PIPE = 19.97(IN.) CRITICAL DEPTH COULD NOT BE CALCULATED. PIPE FLOW VELOCITY = 16.28(FT/S) TRAVEL TIME THROUGH PIPE = 0.04 MIN. TIME OF CONCENTRATION (TC) = 15.00 MIN. ++++++++++++++++++}++}}}}}}}}}}}}}}}}}}}}}+++++++++++++}+}}t}+}}}}}}}} PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 81.960(AC.) • RUNOFF FROM THIS STREAM = 85.320(CFS) TIME OF CONCENTRATION = 15.00 MIN. RAINFALL INTENSITY = 1.886(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 13.000 **** USER DEFINED FLOW INFORMATION AT A POINT **** RAINFALL INTENSITY = 2.104(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.702 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.600; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: TC = 12.30 MIN. RAIN INTENSITY = 2.10(IN/HR) TOTAL AREA = 13.32 (AC. ) TOTAL RUNOFF = 21.92 (CFS) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 • **** IMPROVED CHANNEL TRAVEL TIME **** PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 • STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 21.920(CFS) TIME OF CONCENTRATION = 12.49 MIN. RAINFALL INTENSITY = 2.086(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM No. 3 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 14.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 338.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1205.000 (FT. ) BOTTOM (OF INITIAL AREA) ELEVATION = 1151.000(FT.) DIFFERENCE IN ELEVATION = 54.000(FT.) SLOPE = 0.15976 S(PERCENT)= 15.98 TO = K(0.480)*[(LENGTH"3)/(ELEVATION CHANGE) ]^0.2 INITIAL AREA TIME OF CONCENTRATION = 7.114 MIN. RAINFALL INTENSITY = 2.843(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.742 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX. FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 • INITIAL SUBAREA RUNOFF = 1.772(CFS) TOTAL INITIAL STREAM AREA = 0.840(AC.) UPSTREAM POINT ELEVATION = 1159. 350(FT.) DOWNSTREAM POINT ELEVATION = 1151.000(FT.) • CHANNEL LENGTH THRU SUBAREA = 116.000(FT.) CHANNEL BASE WIDTH 0. 000 (FT. ) SLOPE OR 'Z' OF LEFT CHANNEL HANK = 10.000 SLOPE OR 'Z' OF RIGHT CHANNEL BANK = 10.000 MANNING'S 'N' = 0.015 MAXIMUM DEPTH OF CHANNEL = 0.500(FT.) FLOW(Q) THRU SUBAREA = 21.920(CFS) DEPTH OF FLOW = 0.467(FT.), AVERAGE VELOCITY = 10.047(FT/S) CHANNEL FLOW TOP WIDTH = 9.342(FT.) FLOW VELOCITY = 10.05(FT/S) TRAVEL TIME = 0.19 MIN. TIME OF CONCENTRATION = 12.49 MIN. SUB -CHANNEL NO. 1 CRITICAL DEPTH = 0.781(FT.) CRITICAL FLOW TOP WIDTH = 10.000(FT.) CRITICAL FLOW VELOCITY= 4. 126(FT/S) CRITICAL FLOW AREA = 5.313(SQ.FT) PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 2 • STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 21.920(CFS) TIME OF CONCENTRATION = 12.49 MIN. RAINFALL INTENSITY = 2.086(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM No. 3 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 14.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 338.000(FT.) TOP (OF INITIAL AREA) ELEVATION = 1205.000 (FT. ) BOTTOM (OF INITIAL AREA) ELEVATION = 1151.000(FT.) DIFFERENCE IN ELEVATION = 54.000(FT.) SLOPE = 0.15976 S(PERCENT)= 15.98 TO = K(0.480)*[(LENGTH"3)/(ELEVATION CHANGE) ]^0.2 INITIAL AREA TIME OF CONCENTRATION = 7.114 MIN. RAINFALL INTENSITY = 2.843(IN/HR) FOR A 10.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.742 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX. FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 • INITIAL SUBAREA RUNOFF = 1.772(CFS) TOTAL INITIAL STREAM AREA = 0.840(AC.) PERVIOUS AREA FRACTION = 0.800 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 3 STREAM FLOW AREA = 0.840 (Ac. RUNOFF FROM THIS STREAM = 1.772(CPS) TIME OF CONCENTRATION = 7.11 MIN. RAINFALL INTENSITY = 2.843(IN/HR) SUMMARY OF STREAM DATA: STREAM FLOW RATE TC RAINFALL INTENSITY No. (CFS) (MIN) (IN/HR) 1 85.320 15.00 1.886 2 21.920 12.49 2.086 3 1.772 7.11 2.843 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 85.320 + SUM OF QB IA/IB 21.920 * 0.904 = 19.823 QB IA/IB 1.772 * 0.663 = 1.176 QP = 106.318 • TOTAL OF 3 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 85.320 21.920 1.772 AREA OF STREAMS BEFORE CONFLUENCE: 81.960 13.320 0.840 RESULTS OF CONFLUENCE: TOTAL FLOW PATE = 106.318 (CFS) TIME OF CONCENTRATION = 14.999 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 96.120(AC.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 15.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1151.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1134.800(FT.) LENGTH OF NATURAL CHANNEL = 320.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 107.579(CFS) NATURAL VALLEY CHANNEL TYPE USED L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLISH UNITS)^.352)(SLOPE "0.5) • VELOCITY USING MEAN CHANNEL FLOW = 10.92(FT/S) CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) • NORMAL CHANNEL SLOPE = 0.0506 CORRECTED /ADJUSTED CHANNEL SLOPE = 0.0506 TRAVEL TIME = 0.49 MIN. TC = 15.49 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.683 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 2) = 62.50 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 1.853(IN/HR) FOR A 10.0 YEAR STORM SUBAREA RUNOFF = 2.886(CFS) FOR 2.280(AC.) TOTAL RUNOFF = 109.204(CFS) TOTAL AREA = 98.400(Ac END OF COMPUTATIONS, TOTAL STUDY AREA = 98.40 (AC.) THE FOLLOWING FIGURES MAY BE USED FOR A UNIT HYDROGRAPH STUDY OF THE SAME AREA. AREA AVERAGED PERVIOUS AREA FRACTION(AP) = 0.800 AREA AVERAGED RI INDEX NUMBER = 62.5 0 RIVERSIDE COUNTY RATIONAL HYDROLOGY PROGRAM • CIVILCADD/CIVILDESIGN ENGINEERING SOFTWARE, (C) 1989 - 2004 VERSION 7.0 RATIONAL HYDROLOGY STUDY DATE: 06/05/08 FILE: POST100. OUT ------------------------------------------------------------------------ PARCEL MAP 33488, PAR 2 100 YEAR POST DEVELOPED CONDITION FN:POST100 C\CIVIL\RF\CONNARY ______ ________ *k******* HYDROLOGY STUDY CONTROL INFORMATION ********** ENGLISH (IN -LB) UNITS USED IN INPUT DATA FILE ------------------------------------------------------------------------ PROGRAM LICENSE SERIAL NUMBER 4066 ------------------------------------------------------------------------ RATIONAL METHOD HYDROLOGY PROGRAM BASED ON RIVERSIDE COUNTY FLOOD CONTROL & WATER CONSERVATION DISTRICT 1978 HYDROLOGY MANUAL STORM EVENT (YEAR) = 100.00 ANTECEDENT MOISTURE CONDITION = 3 STANDARD INTENSITY -DURATION CURVES DATA (PLATE D-4.1) STORM EVENT YEAR = 100.0 CALCULATED RAINFALL INTENSITY DATA: I HOUR INTENSITY = 1.300(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 10.000 **** USER DEFINED FLOW INFORMATION AT A POINT **** RAINFALL INTENSITY = 2.791(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.823 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 • PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: FOR THE [ MURRIETA,TMC,RNCH CANORCO ] AREA USED. • 10 YEAR STORM 10 MINUTE INTENSITY = 2.360(IN/HR) 10 YEAR STORM 60 MINUTE INTENSITY = 0.880(IN/HR) 100 YEAR STORM 10 MINUTE INTENSITY = 3.480(IN/HR) 100 YEAR STORM 60 MINUTE INTENSITY = 1. 300(IN/HR) STORM EVENT YEAR = 100.0 CALCULATED RAINFALL INTENSITY DATA: I HOUR INTENSITY = 1.300(IN/HR) SLOPE OF INTENSITY DURATION CURVE = 0.5500 PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 10.000 **** USER DEFINED FLOW INFORMATION AT A POINT **** RAINFALL INTENSITY = 2.791(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.823 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 • PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: • TC = 19.96 MIN. RAIN INTENSITY = 2.79(IN/HR) TOTAL AREA = 81 . 96 (AC. ) TOTAL RUNOFF = 191.28 (CFS) PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 19.000 **** PIPEFLOW TRAVEL TIME (PROGRAM ESTIMATED SIZE) rr++ UPSTREAM POINT/STATION ELEVATION = 1152.500(FT.) DOWNSTREAM POINT/STATION ELEVATION = 1151.000(FT.) PIPE LENGTH = 38.00(FT.) MANNING's N = 0.013 NO. OF PIPES = 2 REQUIRED PIPE FLOW = 191.280(CFS) NEAREST COMPUTED PIPE DIAMETER = 30.00(IN.) CALCULATED INDIVIDUAL PIPE FLOW = 70.690(CFS) NORMAL FLOW DEPTH IN PIPE = 21.56(IN.) FLOW TOP WIDTH INSIDE PIPE = 26.98(IN. ) CRITICAL DEPTH COULD NOT BE CALCULATED. PIPE FLOW VELOCITY = 18. 69(FT/S) TRAVEL TIME THROUGH PIPE = 0.03 MIN. TIME OF CONCENTRATION (TC) = 19.99 MIN. PROCESS FROM POINT/STATION 10.000 TO POINT/STATION 19.000 **** CONFLUENCE OF MAIN STREAMS **+* THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 1 STREAM FLOW AREA = 81.960(AC.) • RUNOFF FROM THIS STREAM = 191.280(CFS) TIME OF CONCENTRATION = 19.99 MIN. RAINFALL INTENSITY = 2.787(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 2 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 13.000 **** USER DEFINED FLOW INFORMATION AT A POINT +*** RAINFALL INTENSITY = 3.108(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.830 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 USER SPECIFIED VALUES ARE AS FOLLOWS: TC = 12.30 MIN. RAIN INTENSITY = 3.11(IN/HR) TOTAL AREA = 13.32(AC.) TOTAL RUNOFF = 35.56(CPS) PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 19.000 • **** IMPROVED CHANNEL TRAVEL TIME *+** UPSTREAM POINT ELEVATION = 1159. 350(FT.) DOWNSTREAM POINT ELEVATION = 1151.000(FT.) • CHANNEL LENGTH THRU SUBAREA = 116.000(FT.) CHANNEL BASE WIDTH 0 000 (FT.) SLOPE OR 'Z' OF LEFT CHANNEL BANK = 10.000 SLOPE OR 'Z' OF RIGHT CHANNEL BANK = 10.000 MANNING'S 'N' = 0.015 MAXIMUM DEPTH OF CHANNEL = 0.500(FT.) FLOW (Q) THRU SUBAREA = 35.560(CFS) DEPTH OF FLOW = 0.550(FT.), AVERAGE VELOCITY = 11.864(FT/S) !WARNING: WATER IS ABOVE LEFT OR RIGHT BANK ELEVATIONS CHANNEL FLOW TOP WIDTH = 10.000(FT.) FLOW VELOCITY = 11.86(FT/3) TRAVEL TIME = 0.16 MIN. TIME OF CONCENTRATION = 12.46 MIN. SUB -CHANNEL NO. 1 CRITICAL DEPTH = 0.984(FT.) CRITICAL FLOW TOP WIDTH = 10.000(FT CRITICAL FLOW VELOCITY= 4.842(FT/S) CRITICAL FLOW AREA = V. 344(SQ. FT) ERROR - CHANNEL DEPTH EXCEEDS MAXIMUM ALLOWABLE DEPTH PROCESS FROM POINT/STATION 13.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: • IN MAIN STREAM NUMBER: 2 STREAM FLOW AREA = 13.320(AC.) RUNOFF FROM THIS STREAM = 35.560(CFS) TIME OF CONCENTRATION = 12.46 MIN. RAINFALL INTENSITY = 3.086(IN/HR) PROGRAM IS NOW STARTING WITH MAIN STREAM NO. 3 PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 14.000 **** INITIAL AREA EVALUATION **** INITIAL AREA FLOW DISTANCE = 338.000(FT. ) TOP (OF INITIAL AREA) ELEVATION = 1205.000(FT.) BOTTOM (OF INITIAL AREA) ELEVATION = 1151.000(FT.) DIFFERENCE IN ELEVATION = 54.000(FT.) SLOPE = 0.15976 S(PERCENT)= 15.98 TC = K(0.480)*((LENGTH^3)/(ELEVATION CHANGE)]^0.2 INITIAL AREA TIME OF CONCENTRATION = 7.114 MIN. RAINFALL INTENSITY = 4.200(IN/HR) FOR A 100.0 YEAR STORM SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.847 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 • RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 INITIAL SUBAREA RUNOFF = 2.989(CFS) TOTAL INITIAL STREAM AREA = 0.840(AC.) • PERVIOUS AREA FRACTION = 0.800 ++++++++++++++++++++++++++++.+++++++++++++++++++++++++++++++++++++++++ PROCESS FROM POINT/STATION 11.000 TO POINT/STATION 14.000 **** CONFLUENCE OF MAIN STREAMS **** THE FOLLOWING DATA INSIDE MAIN STREAM IS LISTED: IN MAIN STREAM NUMBER: 3 STREAM FLOW AREA = 0.840(AC.) RUNOFF FROM THIS STREAM = 2.989(CFS) TIME OF CONCENTRATION = 7.11 MIN. RAINFALL INTENSITY = 4 . 200 (IN/HR) SUMMARY OF STREAM DATA: TOTAL OF 3 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 141.280 35.560 2.989 AREA OF STREAMS BEFORE CONFLUENCE: 81.960 13.320 0.840 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 175.385(CFS) TIME OF CONCENTRATION = 14.994 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 96.120(AC.) ++++++++++++....++++++++++-F+++++++++++++++++++.+++++++i-++++.++++++++++ PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 15.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1151.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1134.800(FT.) LENGTH OF NATURAL CHANNEL = 320.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 177.465 (CFS) NATURAL VALLEY CHANNEL TYPE USED • L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLIS14 DNITS)^.352)(SLOPE^0.5) STREAM FLOW RATE TC RAINFALL INTENSITY No. (CFS) (MIN) (TN/HR) 1 141.280 14.99 2.787 2 35.560 12.46 3.086 3 2.989 7.11 4.200 LARGEST STREAM FLOW HAS LONGER TIME OF CONCENTRATION QP = 141.280 + SUM OF QB IA/IB 35.560 * 0.903 = 32.122 QB IA • 2.989 0.664 = 1.983 QP = 175.385 TOTAL OF 3 MAIN STREAMS TO CONFLUENCE: FLOW RATES BEFORE CONFLUENCE POINT: 141.280 35.560 2.989 AREA OF STREAMS BEFORE CONFLUENCE: 81.960 13.320 0.840 RESULTS OF CONFLUENCE: TOTAL FLOW RATE = 175.385(CFS) TIME OF CONCENTRATION = 14.994 MIN. EFFECTIVE STREAM AREA AFTER CONFLUENCE = 96.120(AC.) ++++++++++++....++++++++++-F+++++++++++++++++++.+++++++i-++++.++++++++++ PROCESS FROM POINT/STATION 14.000 TO POINT/STATION 15.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION **** TOP OF NATURAL CHANNEL ELEVATION = 1151.000(FT.) END OF NATURAL CHANNEL ELEVATION = 1134.800(FT.) LENGTH OF NATURAL CHANNEL = 320.000(FT.) ESTIMATED MEAN FLOW RATE AT MIDPOINT OF CHANNEL = 177.465 (CFS) NATURAL VALLEY CHANNEL TYPE USED • L.A. COUNTY FLOOD CONTROL DISTRICT FORMULA FOR CHANNEL VELOCITY: VELOCITY(FT/S) = (7 + 8(Q(ENGLIS14 DNITS)^.352)(SLOPE^0.5) VELOCITY USING MEAN CHANNEL FLOW = 12.%2 (FTS) • CORRECTION TO MAP SLOPE USED ON EXTREMELY RUGGED CHANNELS WITH DROPS AND WATERFALLS (PLATE D-6.2) NORMAL CHANNEL SLOPE = 0.0506 CORRECTED/ ADJUSTED CHANNEL SLOPE = 0.0506 TRAVEL TIME = 0.42 MIN. TC = 15.41 MIN. ADDING AREA FLOW TO CHANNEL SINGLE FAMILY (1 ACRE LOT) RUNOFF COEFFICIENT = 0.822 DECIMAL FRACTION SOIL GROUP A = 0.000 DECIMAL FRACTION SOIL GROUP B = 0.500 DECIMAL FRACTION SOIL GROUP C = 0.500 DECIMAL FRACTION SOIL GROUP D = 0.000 RI INDEX FOR SOIL (AMC 3) = 80.00 PERVIOUS AREA FRACTION = 0.800; IMPERVIOUS FRACTION = 0.200 RAINFALL INTENSITY = 2.745(IN/HR) FOR A 100.0 YEAR STORM SUBAREA RUNOFF = 5.145(CFS) FOR 2.280(AC.) TOTAL RUNOFF = 180.530(CFS) TOTAL AREA = 98.400(Ac END OF COMPUTATIONS, TOTAL STUDY AREA = 98.40 (AC.) THE FOLLOWING FIGURES MAY BE USED FOR A UNIT HYDROGRAPH STUDY OF THE SAME AREA. AREA AVERAGED PERVIOUS AREA FRACTION (AP) = 0.800 AREA AVERAGED RI INDEX NUMBER = 62.5 / • 0 0 IV EXHIBITS 4 `! PRE D MAM / A 3 914ZOW 1 1 91 11 C6 �1�I��1L�iIi Yj + V,-7 JIL E • w *, MW MITT' left `��• � � y� ++� -. yam' � � • � • l � ® �., •.f_ � � JLC R-1 t . _ . , EL=1134.8 Q10=180.53 CFS ,Q100=47.67 CFS 1 205.0 I% 7 4--71 51 HYDROLOGY STUDY POST DEVELOPED CONDITION SEE PRE—DEVELOPED PARCEL 2, P.M 33488 CONDITION HYDROLOGY STUDY Oro o '559 35 LEGEND: Lpo\sCCFS 73 2.9Ac. TRIBUTARY AREA 197 TRAVEL LENGTH �' 6y NODE NUMBER - FLOW TRAVEL PATH EL=1152.50 Q10=85.32 CFS Q100=141.28 CFS AREA=81.96 Ac. TC 10=14.96 MINS. TC 100=14.96 MINS 10 SEE PRE—DEVELOPED STUDY, DRAINAGE BOUNDARY 80 0 40 80 160 240 1" = 80" GRAPHIC SCALE