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Home My WebLink AboutSUP 06-11; ROBERTSON RANCH PARK; DRAINAGE STUDY FOR ROBERTSON RANCH PA 12 & 13; 2007-09-24DRAINAGE STUDY FOR ROBERTSON RANCH PA 12 & 13 SUP 06-11 Job No. 06-1172/5 February 23, 2007 Revised: September 24, 2007 1t:: Prepared by: O'DAY CONSULTANTS, INC. 2710 Loker Avenue West Suite 100 Carlsbad, California 92010-6603 Tel: (760) 931-7700 Fax: (760) 931-8680 K%sen RCE 60223 Exp. 06/30/08 RECORD COPY jZiLoO - Initial Date iL 60223 6I30108 OF CAL* = /$7 I Date j DRAINAGE STUDY FOR ROBERTSON RANCH PA 12 & 13 SUP 06-11 Job No. 06-1172/5 February 23, 2007 Revised: September 24, 2007 Prepared by: O'DAY CONSULTANTS, INC. 2710 Loker Avenue West Suite 100 Carlsbad, California 92010-6603 Tel: (760) 931-7700 Fax: (760) 931-8680 ~ /7 - 7/0 Keith Hansen RCE 60223 Date Exp. 06/30/08 TABLE OF CONTENTS SECTION 1 INTRODUCTION Purpose of Study Scope Facilities Proposed in City of Carlsbad Master Plan of Drainage Proposed Detention Basins HYDROLOGY Modified Rational Method Description Program Process CONCLUSION Existing Condition Basin Exhibit Proposed Condition Basin Exhibit SECTION 2 Vicinity Map Runoff Coefficients Isopluvial Maps 100-Year, 6-Hour 100-Year, 24-Hour Intensity-Duration Design Chart - Figure 3-1 Overland Time of Flow Nomograph - Figure 3-3 Maximum Overland Flow Length & Initial Time of Concentration - Table 3-2 Nomograph for Determination of Tc for Natural Watersheds - Figure 3-4 San Diego County Soils Interpretation Study SECTION 3 Hydrology 100-Year Analysis Proposed Condition SECTION 4 Temporary Desiltation Basins POCKET Exhibit A - Proposed Condition Drainage Map APPENDIX Hydrologic and Hydraulic Analyses for Robertson's Ranch dated February 20, 2006 by Wayne W. Chang, MS, PE INTRODUCTION Purpose of Study This preliminary drainage study was prepared to determine proposed runoff quantities for Planning Areas 12 & 13 within the Robertson Ranch West Project for the purposes of sizing drainage structures. Scope This study analyzes the 100-year flow for proposed conditions of the site, which is a future park and school. Runoff from this project is combined with runoff from the larger Agua Hedionda watershed before leaving the site through the 8'x8' RCB under El Camino Real. Refer to the February 20, 2006 study titled, Hydrologic and Hydraulic Analyses for Robertson's Ranch prepared by Wayne Chang (Appendix) for pre- and post- developed conditions. HYDROLOGY The hydrologic analyses are being performed according to the 2003 San Diego County Hydrology Manual. The overall drainage area is less than one square mile and includes junctions of independent drainage systems; therefore, the Modified Rational Method is being used for the analyses. The Modified Rational Method is applicable to a 6-hour storm duration because the procedure uses Intensity-Duration Design Charts that are based on a 6-hour storm duration. In some cases, the 6-hour precipitation must be adjusted based on the ratio of the 6- to 24-hour precipitation. This will be performed where necessary. Modified Rational Method Description The modified rational method, as described in the 2003 San Diego County Flood Control/Hydrology Manual, is used to estimate surface runoff flows. The basic equation: Q = CIA C = runoff coefficient (varies with surface) I = intensity (varies with time of concentration A = area in acres U The proposed condition for planning area (PA) 12 :islow density residential)so a runoff condition for PA 13is medium density residential' and coefficient of 0.41 is used. The proposp is estimated to be between 4.3 and 7.3 dwelling units per acre so a runoff coefficient of 0.55 is used. For the 100-year design storm, the 6-hour rainfall amount is 2.6 inches and the 24-hour rainfall amount is 4.3 inches. San Diego County Rational-Hydrology Program Package Version 7.4, developed by CivilCADD/CIVILDESIGN Engineering Software 0 (1991-2004), was used to determine the rainfall amount, times of concentration, corresponding intensities and flows for the various hydrologic basins within this model. The program was then used to route flows through drainage conveyance structures and confluence basins per the modified rational method. Program Process The Rational-Hydrology program is a computer-aided design program where the user develops a node link model of the watershed. Developing independent node link models of each interior watershed and linking these submodels together at confluence points create the node link model. The program has the capability of performing calculations for 11 different hydrologic and hydraulic processes. These processes are assigned and printed in the output. They are as follows: Initial sub-area input, top of stream. Street flow through sub-area, includes sub-area runoff. Addition of runoff from sub-area to stream. Street inlet and parallel street and pipeflow and area. Pipeflow travel time (program estimated pipe size). Pipeflow travel time (user-specified pipe size). Improved channel travel - Area add option. Irregular channel travel time - Area add option. User-specified entry of data at a point. Confluence at downstream point in current stream. Confluence of main streams. CONCLUSION The results of the preliminary analysis of the Robertson Ranch PA 12 & 13 Drain system are presented below. TABLE1 -1 PROPOSED CONDITIONS 100YEAR STORM EVENT AREA BASIN (Acres) SOIL C Q (cfs)1 V (fps)2 12 13.41 D 0.41 15.5 17.3 13 6.62 D 0.55 13.0 11.8 I: cfs = cubic feet per second 2: fps = feet per second G:\OI I0I4\HydmlogyWA I2& 1 3PA 12-13-HYD 4th.doc SITE tTh' Or OEANS1O( wicMWAY. _7& 1TY1IoP CAR WY OF IIST4 RflAriLrL.— pAn :/ U cITY of, SAN MARCO ciircw ENCIM IA S VICINITY MAP an Diego County Hydrology Manual SCC11Ofl 3 No: June 2003 Pgc. 6 of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Ddis*wtaed Natural Terrain (Natural) PICUUMMUOPOnspace 0* 0.20 0.25 0.30 0.35 w Density Residential (LDR) Residential. 1.0 DU/A or less 10 0.27 0.32 036 0.41 w Density Residential (L.DR) Residend4 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 iw Density Residential (LD1t) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 odium Density Residential (MDR) md.ntil 4.3 DU/A or less 30 0.41 0.45 0.48 0.52 alum Density ResidnhiaI (MDR) ResideitiaI, 7.3 DU/A or Less 40 0.48 0.51 0.54 0.57 idium Density RidIntial (MDR). ResidnhI. 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 alum Density Residential (MDR) Residential 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 h Density Residential (IiDR) 24.0 DU/A or low 65 0.66 0.67 0.69 0.71 h Density Residential (iWit) RbI'1i1. 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 cninercial/lndus*rial (N. Corn) Neighborhood Commercial 80 0.76 0.77 0.78 0.79 cnmecial/lndusirial (G. Corn) General Commercial 85 080 0.80 0.81 0.82 ercaWlndustrial (OP. Corn) Office Professional/Commercial 90 0.83 0.84 0.84 0.85 nmercial/Lud_uswial (Limited I) Limited lndusthal 90 0.83 0.84 0.84 0.85 nmercial/lndusuial (General I.) General Industrial 95 0.87 0.87 0.87 0.87 te values associated with 00/9 impervious may be used for direct calculatien of the ineoff co'iit es diaercd in Section 3.12 (iquesonling the PerVIOUS runoff czen1 Cp, for the soil type),, or foresees that will remain uadiwbod in perpetuity. 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[!J1JEEAII!1E1FXEIL!3 __E E [J_'• E! iILE!JEJ -E HIED nam EEE :• EJ1L 1J JEJEJ faRE!JJ RimWE I" "F73WKIMM wJ E IiI[1 [1TWD ]fJIiIiIfl!I1W1 LIAM SKI =E-f-3uiWK3uE3 19--7111 100 20 10 EXAMPLE: Given: Wate,ourse Dietence (D) = 70 Feet Slope (a) Runoff Coefficient (C) = 0.41 Overland Flow Time (T) = 9.5 Minutes T =1.8(1.1 sy;- SOURCE: Airport Federal Aviation AdmInistration, 1965 FIGURE Rational Formula - Overland Time of Flow Homograph H 3=3 H San Diego County Hydrology Manual Date: June 2003 Section: 3 Page: 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect wiere the drainage basin area is 20 to 600 acres Table 3-2 provides limits of the length (Maximum Length (L7)) of sheet flow to be used in hydtology studies. Initial Tj values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a. detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) & INITIAL TIME OF CONCENTRATION (T1 Element DU/ Acre .5% 1% 2% 3% 5% 10% Ti L.. iL IL Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR. 2 50 111 ..2 J 9.2 100 88 100 7.4 JQQ 58 LDR. 2.9 50 10.7 70 10.0 85 8.8 95 Wi 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.01100 4.8 MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N. Corn 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G. Corn 50 4.7 60 4.1 75 3.6 85 3.4 90 2.91 100 2.4 O.P./Com 50 1 4.2 60 1 3.7 70 3.1 80 2.9 90 2.61100 2.2 Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General 1. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 1 100 1.9 See Table 3-1 for more detailed description EQUATION AE Feet Ta QTE SY-3U To a Thniofco new nitationhoum) L Watvcoumo Distancm nlM) eft 4000 hi on along r. etevoll s One ( Ar• 34)(feet) 3000 Ta Ho Minutes 2001 4 240 3 1S0 1000 'IS • 2 120 IN 105 N 0II 'I 4 11 If 1 10 301 SO • 200 40 L Mae Fed 36 L100 4000 20 TI-' Is 1— 3000 II 0.0_i.. \ 14 1-. 2000 12 1000 1G 1400 \ I 1200 5 1000 7 005 S To S 500 4 400 300 3 II 40 30 20 10 1200 A L OURCE: Cal Womia DMs$on of Hlgh (1941) and K(rp3ch (1940) FIGURE Homograph for Determlnatton of ntrnsn (Tal or Travel Time ITft for Natural Vtenteds ;Ida 36 I - 32 '- I D I \ir GG D '0• 4 \ D 6 CHESTNU MY 1,jfJ .-S rr-' G (H E. 0 i OND lu CARLsft4 V, C I B A d Adud Hecd via -PIP 7L A SM12O1 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering software, (c) 1993 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 02/22/07 ------------------------------------------------------------------------ ROBERTSON RANCH PA 12 PROPOSED: PARK G:\ACCTS\011014\PA1201.0UT ****** Hydrology study Control Information O'Day consultants, San Deigo, California - S/N 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitation(inches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'C' values used Runoff coefficients by rational method 'S. Process from Point/Station 201.000 to Point/Station 202 000 INITIAL AREA EVALUATION **** User specified 'C' value of 0.,410 given-for subarea Initial subarea flow distance = ].00;O0(Ft.) Highest elevation = 67.70(Ft.) Lowest elevation = 65.70(Ft.) Elevation difference = 2.00(Ft.) Time of concentration calcUlated by the urban areas overland flow method (App X-C) = 9.86 mm. TC = f1.8*(1.1_C)*distanceA.5)/(% slopeA(1/3)) rc = (1.8*(1.1_0..4100)*(100.00A.5)/( 2.00A(1/3)]= 9.86 Rainfall intensity (I) = :4.421'for a 100.0 year storm Effective runoff coefficient used for area (Q=KcIA) is C = 0.410 Subarea runoff = 0.272(CFS) Total initial stream area = 0.150(Ac.) Process from Point/Station 202.000 to Point/Station 203.000 IRREGULAR CHANNEL FLOW TRAVEL TIME Estimated mean flow rate at midpoint of channel = 1.631(CFS) Depth of flow = 0.193(Ft.), Average velocity = 1.098(Ft/s) Irregular Channel Data Information entered for subchannel number 1 Point number 'x' coordinate 'Y' coordinate 1 0.00 .0.50 2 20.00 0.00 3 40.00 0.50 Pagel L SM12O1 Manning's 'N' friction factor = 0.040 ----------------------------------------------------------------- sub-channel flow = 1.632(CFS) flow, top width = 15.417(Ft.) velocity= 1.098(Ft/s) area = 1.485(Sq.Ft) Froude number = 0.624 upstream point elevation = 65.700(Ft.) Downstream point elevation = 56.000(Ft.) Flow length = 490.000(Ft.) Travel time = 7.44 mm. Time of concentration = 17.29 mm. Depth of flow = 0.193(Ft.) Average velocity = 1.098(Ft/S) Total irregular channel flow = 1.631(CFS) Irregular channel normal depth above invert elev. = 0.193(Ft.) Average velocity of channel(s) = 1.098(Ft/s) sub-Channel No. 1 critical depth = 0.160(Ft.) critical flow top width = 12.813(Ft.) critical flow velocity= 1.590(Ft/s) critical flow area = 1.026(Sq.Ft) Adding area flow to channel user specified 'C' value of 0.410 given for subarea Rainfall intensity 3.077(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.410 subarea runoff = 1.892(CFS) for 1.500(Ac.) Total runoff = 2.164(CFS) Total area = 1.65(Ac.) Process from Point/Station 203.000 to Point/Station 204.000 IRREGULAR CHANNEL FLOW TRAVEL TIME Estimated mean flow rate at midpoint of channel = 5.901(CFS) Depth of flow = 0.727(Ft.), Average velocity = 2.233(Ft/5) Irregular channel Data Information entered for subchannel number 1 : . -- Point number 'x' coordinate 'V' coordinate 1 0.00 1.00 2 5.00 i0OO 3 10.00 ('1.00 Manning's 'N' friction factor = 0.040 Sub-channel flow = 5.902 (CFS) ' flow top width = 7.272(Ft.) velocity= 2.233(Ft/s) area = 2.644(Sq.Ft) Froude number = 0.652 upstream point elevation = 56.000(Ft.) Downstream point elevation = 50.000(Ft.) Flow length = 420.000(Ft.) Travel time = 3.14 mm. Time of concentration = 20.43 mm. Depth of flow = 0.727(Ft.) Average velocity = 2.233(Ft/s) Total irregular channel flow = 5.902(CFS) Irregular channel normal depth above invert elev. = 0.727(Ft.) Average velocity of channel(s) = 2.233(Ft/s) Page 2 ((1 sub-channel No. 1 critical depth = 0.613(Ft.) critical flow top width = 6.133(Ft.) critical flow velocity= 3.139(Ft/s) critical flow area = 1.881(Sq.Ft) Adding area flow to channel user specified 'C' value of 0.410 given for subarea Rainfall intensity = 2.763(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rationatmethod,Q=KCIA, C = 0.410 subarea runoff = 6.458(CFS) for (5'700(Ac.) Total runoff = 8.622(CFS) Total area = 7.35(Ac.) Process from Point/Station 204.000-to Point/Station 204.000 SUBAREA. FLOW-ADDITION - user specified 'C' value of 0.410 given for subarea Time of concentration = 20.43 mm. Rainfall intensity = 2.763(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rationalmeth0d,Q=KCIA, C = 0.410 subarea runoff = 6.866(CFS) for 6;060(Ac.) Total runoff = 15.488(CFS) Total area = 13.41(Ac.) End of computations, total study area = 13.41 (Ac.) Page 3 * O'Day Consultants, Inc. * * 2710 Loker Avenue West, Suite 100 * * Carlsbad, CA 92008 * Tel: 760-931-7700 Fax: 760-931-8680 * Inside Diameter 18.00 in.) * * * * * * * AAAAAAAAAAAAAAAAAAAAA A * Water * * * I * * C 8.65 in.) 0.720 ft.) * * I * * * V Circular Channel Section ------------------------ Flowrate ..................15.500 CFS Velocity ..................18.474 fps Pipe Diameter .............18.000 inches Depth of Flow .............8.645 inches Depth of Flow .............0.720 feet Critical Depth ............1.415 feet Depth/Diameter (D/d) 0.480 Slope of Pipe .............10.000 % X-Sectional Area 0.839 sq. ft. Wetted Perimeter 2.297 feet A(2/3) ..................0.429 Mannings 'n' ..............0.013 Min. Fric. Slope, 18 inch Pipe Flowing Full 2.178 % PA1301. OUT San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (C) 1993 version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 1985 hydrology manual Rational Hydrology Study Date: 08/08/07 ------------------------------------------------------------------------ ROBERTSON RANCH PA 13 PROPOSED CONDITION G:\ACCTS011014\PA 12 & 13\4TH PC\PA1301.OuT Hydrology Study Control Information ------------------------------------------------------------------------ O'Day Consultants, San Deigo, California - S/N 10125 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitation(inches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'C' values used Runoff coefficients by rational method Process from Point/Station r101.000 to Point/Station 102000 INITIAL AREA EVALUATION Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [SINGLE FAMILY area type ] Initial subarea flow distance = 130.00(Ft.) Highest elevation = 70.80(Ft.) Lowest elevation = 68.00(Ft.) Elevation -difference = 2.80(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 8.74 mm. TC = [1.8*(1.1_C)*distanceA.5)/(% slopeA(1/3)] TC = [1.8*(1.1_0.5500)*(130.00A.5)/( 2.15A(1/3)1= 8.74 Rainfall intensity (I) = 4.778 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C =(.0.550 subarea runoff = 0.473(CFs) A. Total initial stream area = 0.180(Ac.) Process from Point/Station 102.000 to Point/Station 103.000 IRREGULAR CHANNEL FLOW TRAVEL TIME Estimated mean flow rate at midpoint of channel = 1.261(CFS) Depth of flow = 0.436(Ft.), Average velocity = 1.328(Ft/s) Irregular Channel Data ----------------------------------------------------------------- Information entered for subchannel number Page 1 PA13O1. OUT Point number 'x' coordinate 'Y' coordinate 1 0.00 1.00 2 5.00- 0.00 3 10.00 1.00 Manning's 'N' frictionfactor = 0.040 ----------------------------------------------------------------- Sub-Channel flow = 1.261(CFS) flow top width = 4.359(Ft.) velocity= 1.328(Ft/s) area = 0.950(Sq.Ft) Froude number = 0.501 upstream point elevation = 68.000(Ft.) Downstream point elevation = 66.200(Ft.) Flow length = 180.000(Ft.) Travel time = 2.26 mm. Time of concentration = 11.00 mm. Depth of flow = 0.436(Ft.) Average velocity = 1.328(Ft/s) Total irregular channel flow = 1.261(CFS) Irregular channel normal depth above invert elev. = 0.436(Ft.) Average velocity of channel(s) = 1.328(Ft/s) Sub-Channel No. 1 critical depth = 0.330(Ft.) critical flow top width = 3.301(Ft.) critical flow velocity= 2.316(Ft/s) critical flow area = 0.545(Sq.Ft) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D-,=-1.000 [SINGLE FAMILY area type ] Rainfall intensity = 4.120(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.550 Subarea runoff = 1.359(CFS) for 0.600(Ac.) Total runoff = 1.833(cFS) Total area = 0.78(Ac.) Process from Point/Station 103.000-to Point/Station 104.000 IRREGULAR CHANNEL FLOW TRAVELTIME Estimated mean flow rate at midpoint of channel = 3.477(CFS) Depth of flow = 0.620(Ft.), Average velocity = 1.809(Ft/s) Irregular channel Data ----------------------------------------------------------------- Information entered for subchannel number 1 Point number 'x' coordinate 'Y' coordinate 1 0.00 1.00 2 5.00 0.00 3 10.00 1.00 Manning's 'N' friction factor = 0.040 ----------------------------------------------------------------- Sub-Channel flow = 3.477(CFs) flow top width = 6.200(Ft.) velocity= 1.809(Ft/s) area = 1.922(Sq.Ft) Froude number = 0.573 upstream point elevation = 66.200(Ft.) Downstream point elevation = 63.300(Ft.) Page 2 PA1301. OUT Flow length = 250.000(Ft.) Travel time = 2.30 mm. Time of concentration = 13.30 mm. Depth of flow = 0.620(Ft.) Average velocity = 1.809(Ft/s) Total irregular channel flow = 3.477(CFS) Irregular channel normal depth above invert elev. = 0.620(Ft.) Average velocity of channel(s) = 1.809(Ft/s) Sub-Channel No. 1 critical depth = 0.496(Ft.) * critical flow top width = 4.961(Ft.) critical flow velocity= 2.826(Ft/s) critical flow area = 1.231(Sq.Ft) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [SINGLE FAMILY area type ] Rainfall intensity = 3.644(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.550 Subarea runoff = 2.806(CFS) for 1400(Ac.) Total runoff = 4.639(CFS) Total area = 2.18(Ac.) +++++++-H-++++++++++++++++++++-f++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105c000 IRREGULAR CHANNEL FLOW TRAVEL TIME 11c Estimated mean flow rate at midpoint of channel = 7.202(CFS) Depth of flow = 0.838(Ft.), Average velocity = 2.053(Ft/s) Irregular Channel Data ----------------------------------------------------------------- Information entered for subchannel number 1 Point number 'x' coordinate 'v' coordinate 1 0.00 2 1.00 2 5.O0 0.00 3 10.00 1.00 Manning's 'N' friction'factor = 0.040' Sub-Channel flow = 7.202(CFS)' flow top width = 8.377(Ft.) velocity= 2.053(Ft/s) area = 3.509(Sq.Ft) Froude number = 0.559 Upstream point elevation = 63.300(Ft.) Downstream point elevation = 61.600(Ft.) Flow length = 170.000(Ft.) Travel time = 1.38 mm. Time of concentration = 14.68 mm. Depth of flow = 0.838(Ft.) Average velocity = 2.053(Ft/s) Total irregular channel flow = 7.202(CFS) Irregular channel normal depth above invert elev. = 0.838(Ft.) Average velocity of channel(s) = 2.053(Ft/s) Sub-Channel No. 1 critical depth = 0.664(Ft.) * ' critical flow top width = 6.641(Ft.) critical flow velocity= 3.267(Ft/s) critical flow area = 2.205(Sq.Ft) Page 3 PA1301 . OUT Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [SINGLE FAMILY area type ] Rainfall intensity = 3.419(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.550 Subarea runoff = 4.532(CFS) for 2.410(Ac.) Total runoff = 9.171(cFs) Total area= 4.59(Ac.) Process from Point/Station 105.000 to Point/Station 105.000 SUBAREA FLOW ADDITION Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [SINGLE FAMILY area type ] Time of concentration = 14.68 mm. Rainfall intensity = 3.419(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.550 Subarea runoff = 3.818(CFs) for 2.030(Ac.) Total runoff = 12.989(cFs) Total area = 6.62(Ac.) End of computations, total study area = 6.62 (Ac.) Page 4 * O'Day Consultants, Inc. * * 2710 Loker Avenue West, Suite 100 * * Carlsbad, CA 92008 * Tel: 760-931-7700 Fax: 760-931-8680 * Inside Diameter 24.00 in.) * * * * * * * AAAAAAAA*AAAAAAAAAAAA - - A * Water * * * I * •* ( 6.27 in.) 0.522 ft.) * * I * * I * V Circular Channel Section ------------------------ Flowrate ..................13.000 CFS Velocity ..................19.902 fps Pipe Diameter .............24.000 inches Depth of Flow .............6.269 inches Depth of Flow .............0.522 feet Critical Depth ............1.297 feet Depth/Diameter (D/d) 0.261 Slope of Pipe .............14.800 % X-Sectional Area 0.653 sq. ft. Wetted Perimeter 2.146 feet ARA(2/3) ..................0.296 Mannings 'n' ..............0.013 min. Fric. Slope, 24 inch Pipe Flowing Full 0.330 %