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»»>RATIONAL METHOD INITIAL SUBAREA ANALYSIS««< <br />»USE TIME -OF -CONCENTRATION NOMOGRAPH FOR INITIAL SUBAREA<< <br />INITIAL SUBAREA FLOW-LENGTH(FEET) = 300.00 <br />ELEVATION DATA: UPSTREAM(FEET) = 171.30 DOWNSTREAM(FEET) = 168.50 <br />Tc - K*[(LENGTH" 3.00)/(ELEVATION CHANGE)]"0.20 <br />SUBAREA ANALYSIS USED MINIMUM Tc(MIN.) = 7.581 <br />* 100 YEAR RAINFALL INTENSITY(INCH/HR) = 4.875 <br />SUBAREA Tc AND LOSS RATE DATA(AMC II): <br />DEVELOPMENT TYPE/ SCS SOIL AREA Fp Ap SCS Tc <br />LAND USE GROUP (ACRES) (INCH/HR) (DECIMAL) CN (MIN.) <br />COMMERCIAL B 3.00 0.30 0.100 56 7.58 <br />SUBAREA AVERAGE PERVIOUS LOSS RATE, Fp(INCH/HR) = 0.30 <br />SUBAREA AVERAGE PERVIOUS AREA FRACTION, Ap = 0.100 <br />SUBAREA RUNOFF(CFS) - 13.08 <br />TOTAL AREA(ACRES) - 3.00 PEAK FLOW RATE(CFS) - 13.08 <br />a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <br />FLOW PROCESS FROM NODE 251.00 TO NODE 252.00 IS CODE = 51 <br />»»>COMPUTE TRAPEZOIDAL CHANNEL FLOW««< <br />»»>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) ««< <br />---------------------------------------------------------------------------- <br />ELEVATION DATA: UPSTREAM(FEET) = 168.50 DOWNSTREAM(FEET) = 167.00 <br />CHANNEL LENGTH THRU SUBAREA(FEET) = 130.00 CHANNEL SLOPE = 0.0115 <br />CHANNEL BASE(FEET) = 220.00 "Z" FACTOR = 99.000 <br />MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 <br />* 100 YEAR RAINFALL INTENSITY(INCH/HR) = 4.377 <br />SUBAREA LOSS RATE DATA(AMC II): <br />DEVELOPMENT TYPE/ SCS SOIL AREA Fp Ap SCS <br />LAND USE GROUP (ACRES) (INCH/HR) (DECIMAL) CN <br />COMMERCIAL B 1.04 0.30 0.100 56 <br />SUBAREA AVERAGE PERVIOUS LOSS RATE, Fp(INCH/HR) = 0.30 <br />SUBAREA AVERAGE PERVIOUS AREA FRACTION, Ap = 0.100 <br />TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 15.12 <br />TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.38 <br />AVERAGE FLOW DEPTH(FEET) = 0.05 TRAVEL TIME(MIN.) = 1.57 <br />Tc(MIN.) - 9.15 <br />SUBAREA AREA(ACRES) = 1.04 SUBAREA RUNOFF(CFS) = 4.07 <br />EFFECTIVE AREA(ACRES) = 4.04 AREA -AVERAGED Fm(INCH/HR) = 0.03 <br />AREA -AVERAGED Fp(INCH/HR) = 0.30 AREA -AVERAGED Ap = 0.10 <br />TOTAL AREA(ACRES) = 4.0 PEAK FLOW RATE(CFS) = 15.81 <br />END OF SUBAREA CHANNEL FLOW HYDRAULICS: <br />DEPTH(FEET) - 0.05 FLOW VELOCITY(FEET/SEC.) - 1.39 <br />LONGEST FLOWPATH FROM NODE 250.00 TO NODE 252.00 = 430.00 FEET. <br />a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <br />FLOW PROCESS FROM NODE 252.00 TO NODE 260.00 IS CODE = 91 <br />»»>COMPUTE PIPE -FLOW TRAVEL TIME THRU SUBAREA««< <br />»»>USING USER -SPECIFIED PIPESIZE (EXISTING ELEMENT) ««< <br />---------------------------------------------------------------------------- <br />ELEVATION DATA: UPSTREAM(FEET) = 142.00 DOWNSTREAM(FEET) = 137.00 <br />FLOW LENGTH(FEET) = 318.00 MANNING'S N = 0.013 <br />DEPTH OF FLOW IN 24.0 INCH PIPE IS 13.0 INCHES <br />PIPE -FLOW VELOCITY(FEET/SEC.) = 9.09 <br />GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 <br />PIPE-FLOW(CFS) - 15.81 <br />PIPE TRAVEL TIME(MIN.) - 0.58 Tc(MIN.) - 9.73 <br />LONGEST FLOWPATH FROM NODE 250.00 TO NODE 260.00 = 748.00 FEET. <br />a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <br />FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 1 <br />»»>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE««< <br />»»>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES««< <br />TOTAL NUMBER OF STREAMS = 2 <br />CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: <br />TIME OF CONCENTRATION(MIN.) - 9.73 <br />RAINFALL INTENSITY(INCH/HR) = 4.22 <br />FA <br />