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Home My WebLink AboutCDP 2023-0040; 4080 SUNNYHILL DRIVE; DRAINAGE STUDY; 2025-03-11Rosenhan Residence Standard Development Project 1 PREPARED BY: CE&LST CORPORATION 171 SAXONY ROAD, SUITE 213 ENCINITAS, CA 92024 (760) 436-0660 Original Date: 12-17-24 Revised January 23, 2025 Revised March 11, 2025 CITY OF CARLSBAD ENGINEERING DIVISION DRAINAGE STUDY FOR GR2024-0017, CDP2023-0040 ROSENHAN RESIDENCE 4080 SUNNYHILL DRIVE APN 207-072-21 ENGINEER OF WORK _______________________________________________________________________ JOEL VALDOVINOS – RCE 65256 I ,?..,_ V,/M-6 I -ecEI.ST Rosenhan Residence Standard Development Project 2 TABLE OF CONTENTS PAGES Introduction (Existing and Proposed Conditions) 3 Vicinity Map 4 Hydrologic Analysis Criteria 5 Stormwater Summary 6 Conclusions 6 Responsible Charge 7 APPENDICES Existing Impervious Area Calculations Basin 1 Existing Impervious Area Calculations Basin 2 Existing Drainage Study Calculations Basin 1 Existing Drainage Study Calculations Basin 2 Proposed Impervious Area Calculations Basin 1 Proposed Impervious Area Calculations Basin 2 Proposed Drainage Study Calculations Basin 1 Proposed Drainage Study Calculations Basin 2 Offsite Impervious Area Calculations Basin Offsite Drainage Study Calculations Basin Brow Ditch Calculation 6” PVC pipe Calculations Cross Gutter Calculations Hydrologic Soil Group Sheets Runoff Coefficient for Urban Areas Intensity Duration Design Chart Figure 3-3 Overland Time of Flow Nomograph 100-year, 6 hour Isopluvial map 100-year, 24 hour Isopluvial map Existing Conditions Map Proposed Conditions Map Offsite Condition Map Rosenhan Residence Standard Development Project 3 Introduction: Existing Conditions The subject property is approximately 0.34 gross acres and is located on the easterly side of Sunnyhill Drive, in the City of Carlsbad. The property has been previously developed with a single-family residence, detached garage, concrete driveway, flatwork, landscaping, etc. The subject property’s storm water runoff sheet flows across the surface, east to west toward the Right of Way of Sunnyhill Drive. There is no existing public storm drain located onsite. This project proposes to maintain the historical drainage pattern No runoff from the subject property currently drains onto adjacent properties. However, there is offsite runoff from the east of the subject property that drains to an existing catch basin located at the northwest corner of the adjacent property (APN 207-072-22) which offsite runoff is discharged to the southeast corner of the subject property through an existing 6’’ storm drain pipe which then drains along the existing concrete driveway toward the Right of Way on Sunnyhill Drive. In the Existing Conditions the watersheds are divided into 3 basins, refer to the Existing Drainage Maps; Basin 1, Basin 2 and Offsite Basin. The corresponding runoff coefficients are: Basin 1= 0.83, Basin 2=0.85 and Offsite Basin=0.64; in addition, the flows for each Basin are as follows: Basin 1 = 1.04 cfs, Basin 2 = 0.73 cfs and Offsite Basin= 0.98 cfs. Proposed Condition The owner proposes to construct a single-family residence, detached garage, Accessory Dwelling Unit (ADU), pool, concrete surfaces, permeable driveway, retaining walls, landscaping, and others associated minor improvements. The project anticipates a decrease in runoff due to the decrease of impervious surface area. In the Proposed Conditions the watersheds are divided into 3 basins, refer to the Proposed Drainage Maps; Basin 1, Basin 2 and Offsite Basin. The corresponding runoff coefficients are: Basin 1= 0.78, Basin 2=0.66 and Offsite Basin=0.64; in addition, the flows for each Basin are as follows: Basin 1 = 0.82 cfs, Basin 2 = 0.78 cfs and Offsite Basin= 0.98 cfs. Runoff from Basin 1,will be collected mainly through planter areas that eventually discharge at the most northwesterly corner of the property into a proposed rip-rap energy dissipater before entering the public right of way on Sunnyhill Drive. Runoff from the adjacent property (APN 207-072-22) in the proposed condition will be collected via two ways, with an proposed brow ditch along the most easterly property line and by demoing a portion of the existing 6- inch storm drain pipe and rerouting it to a proposed catch basin at the very southeast corner of the property, from which will be routed using a 6” PVC pipe that will discharge just west of the proposed planter into a proposed 3’x2’ rip rap pad in order to reduce velocities prior to entering the public right on Sunnyhill Drive. The rest of Basin 2 runoff will be directed to a planter area on the southwest corner of the property, runoff will be discharged through a rip-rap energy dissipater prior to discharge to the Sunnyhill Drive Right of Way. See attached drainage maps and calculations. Offsite Condition The owner proposes to construct a single-family residence, detached garage, Accessory Dwelling Unit (ADU), pool, concrete surfaces, permeable driveway, retaining walls, landscaping, and others associated improvements. The project anticipates the decrease in runoff due to the decrease of impervious surface area. Rosenhan Residence Standard Development Project 4 e c1:1.s. CITY OF OCEANSIDE HIGKIYAY 7a PACIFIC OCEAN CITY OF ENCINITAS NOT TO SCALE Rosenhan Residence Standard Development Project 5 Hydrologic Analysis Criteria: The County of San Diego version (2003) of the hydrology method will be utilized to prepare the hydrologic analysis; in addition, hand calculations will be utilized to help compute flows. Runoff coefficients were based on Table 3-1 for the Cp values; interpolation equation was used to determine runoff coefficients in representation of the existing and proposed conditions. The hydrologic watersheds are presented in the section for existing and proposed maps; it shows basin and boundaries of the watershed and its corresponding runoff coefficients. Both existing and proposed conditions assume soil type “B”. The peak rates of runoff generated by the 100-year storm event will be used to size drainage facilities associated with this project, if any. EXISTING HYDROLOGIC CONDITION Basin Number Basin area (acres) 100-year peak discharge (cfs) Basin 1 0.21 1.04 Basin 2 0.13 0.73 PROPOSED HYDROLOGIC CONDITION Basin Number Basin area (acres) 100-year peak discharge (cfs) Basin 1 0.16 0.82 Basin 2 0.18 0.78 OFFISITE HYDROLOGIC CONDITION Basin Number Basin area (acres) 100-year peak discharge (cfs) Basin 0.23 0.98 Summary: Existing Conditions Proposed Conditions Offsite Conditions Total Area = 0.34AC Total Area = 0.34 AC Total Area = 0.23 AC Total Flow = 1.77 cfs Total Flow = 1.60 cfs Total Flow=0.98 cfs Rosenhan Residence Standard Development Project 6 Storm Water Quality Summary: The development proposes to reduce the discharge of pollutants by utilizing Source Control and Low Impact Development (LID) BMP’s to the maximum extent practical. Impervious hardscape has been designed to disperse runoff away from the building to landscape areas, and planter areas before being conveyed to Sunnyhill Drive. Conclusion: During the 100-year storm the site will experience a flow of 0.17 CFS less than the existing 100-year storm flow of 1.77 CFS this decrease can be attributed to the decrease of impervious area of 1,748 sf. The project is not within a FLOOD HAZARD zone; therefore, the proposed improvements will not be impacted by 100-year flood zone. Similarly, this project does not propose any significant risk of loss or death involving. Rosenhan Residence Standard Development Project 7 DECLARATION OF RESPONSIBLE CHARGE: I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THIS PROJECT, THAT I HAVE EXERCISED RESONSIBLE CHARGE OVER THE DESIGN OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS. I UNDERSTAND THAT THE CHECK OF PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF CARLSBAD IS CONFINED TO A REVIEW ONLY AND DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITIES FOR THE PROJECT. 3-11-25 Joel Valdovinos, P.E. DATE RCE 65256 EXP. 09-30-25 JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 1-15-25 v-calcs-impervious v-calcs-pervious DESCRIPTION IMPERVIOUS (SF) DESCRIPTION PERVIOUS (SF) TOTAL (SF) Existing Residence 949.00 Landscape 2697.00 Garage Shed 505.00 Concrete 4272.00 Σ : 5726.00 Σ : 2697.00 = 8423.00 68% 32% + IMPERVIOUS AREA CALCULATIONS Note: Areas from AutoCAD ** Impervious Areas per Layer: **Pervious Areas per Layer: EXISTING DRAINAGE BASIN 1 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 1-15-25 v-calcs-impervious v-calcs-pervious DESCRIPTION IMPERVIOUS (SF) DESCRIPTION PERVIOUS (SF) TOTAL (SF) Existing Residence 980.00 Landscape 1426.00 Garage 514.00 Shed 87.00 Concrete 2655.00 Σ : 4236.00 Σ : 1426.00 = 5662.00 75% 25% + IMPERVIOUS AREA CALCULATIONS EXISTING DRAINAGE BASIN 2 Note: Areas from AutoCAD ** Impervious Areas per Layer: **Pervious Areas per Layer: 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 01-15-25 Area =8,423 SF 0.19 AC D =159 ( Watercourse Distance, FT ) S =13.27 ( Slope, % ) PER SDC HYDROLOGY USE 5.00 MIN P 2 =1.3 ( 2-Year, 6-Hour Isopluvial ) P10 =1.7 ( 10-Year, 6-Hour Isopluvial ) P100 =2.5 ( 100-Year, 6-Hour Isopluvial ) I2 ===3.43 IN/HR I10 ===4.48 IN/HR I 100 == =6.59 IN/HR Q2 ===0.54 CFS Q10 ===0.71 CFS Q 100 == =1.04 CFS * Per San Diego County Hydrology Manual 2003 C I A (0.83)(6.59 IN/HR)(0.19 AC) T c1 =1.8(1.1 - C)(D)1/2 =1.8(1.1-0.69)(159)^1/2 MIN(S)1/3 (13.27)^1/3 7.44 P100 DTc1 -0.645 7.44(2.5)(5)^(-0.645) 7.44 P2 DTc1-0.645 7.44(1.3)(5)^(-0.645) 7.44 P10 DTc1-0.645 7.44(1.7)(5)^(-0.645) 1.98 = C I A (0.83)(3.43 IN/HR)(0.19 AC) C I A (0.83)(4.48 IN/HR)(0.19 AC) DRAINAGE STUDY CALCULATOR EXISTING DRAINAGE BASIN 1 DESCRIPTION: C*=(0.90)(%IMP)+CP(1-%IMP) =(0.90)(0.68) + (0.69)(1-0.68) =0.83 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 01-15-25 Area =5,662 SF 0.13 AC D =177 ( Watercourse Distance, FT ) S =9.94 ( Slope, % ) PER SDC HYDROLOGY USE 5.00 MIN P 2 =1.3 ( 2-Year, 6-Hour Isopluvial ) P10 =1.7 ( 10-Year, 6-Hour Isopluvial ) P100 =2.5 ( 100-Year, 6-Hour Isopluvial ) I2 ===3.43 IN/HR I10 ===4.48 IN/HR I 100 == =6.59 IN/HR Q2 ===0.38 CFS Q10 ===0.49 CFS Q 100 == =0.73 CFS * Per San Diego County Hydrology Manual 2003 C I A (0.85)(6.59 IN/HR)(0.13 AC) 7.44 P100 DTc1-0.645 7.44(2.5)(5)^(-0.645) C I A (0.85)(3.43 IN/HR)(0.13 AC) C I A (0.85)(4.48 IN/HR)(0.13 AC) MIN(S)1/3 (9.94)^1/3 7.44 P2 DTc1 -0.645 7.44(1.3)(5)^(-0.645) 7.44 P10 DTc1-0.645 7.44(1.7)(5)^(-0.645) 0.85 =1.98Tc1=1.8(1.1 - C)(D)1/2 =1.8(1.1-0.74)(177)^1/2 DRAINAGE STUDY CALCULATOR EXISTING DRAINAGE BASIN 2 DESCRIPTION: C*=(0.90)(%IMP)+CP(1-%IMP) =(0.90)(0.748) + (0.74)(1-0.748) = 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 1-15-25 v-calcs-impervious v-calcs-pervious DESCRIPTION IMPERVIOUS (SF) DESCRIPTION PERVIOUS (SF) TOTAL (SF) Existing Residence 1571.00 Landscape 2985.00 Garage Covered Patio 488.00 Concrete 1925.00 Σ : 3984.00 Σ : 2985.00 = 6969.00 57% 43% + IMPERVIOUS AREA CALCULATIONS Note: Areas from AutoCAD ** Impervious Areas per Layer: **Pervious Areas per Layer: PROPOSED DRAINAGE BASIN 1 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 1-15-25 v-calcs-impervious v-calcs-pervious DESCRIPTION IMPERVIOUS (SF) DESCRIPTION PERVIOUS (SF) TOTAL (SF) Existing Residence 332.00 Landscape 4365.00 Garage 514.00 Pavers 2368.00 Shed 0.00 Concrete 261.00 Σ : 1107.00 Σ : 6733.00 = 7840.00 14% 86% + IMPERVIOUS AREA CALCULATIONS PROPOSED DRAINAGE BASIN 2 Note: Areas from AutoCAD ** Impervious Areas per Layer: **Pervious Areas per Layer: 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 01-15-25 Area =6,969 SF 0.16 AC D =159 ( Watercourse Distance, FT ) S =13.27 ( Slope, % ) PER SDC HYDROLOGY USE 5.00 MIN P 2 =1.3 ( 2-Year, 6-Hour Isopluvial ) P10 =1.7 ( 10-Year, 6-Hour Isopluvial ) P100 =2.5 ( 100-Year, 6-Hour Isopluvial ) I2 ===3.43 IN/HR I10 ===4.48 IN/HR I 100 == =6.59 IN/HR Q2 ===0.43 CFS Q10 ===0.56 CFS Q 100 == =0.82 CFS * Per San Diego County Hydrology Manual 2003 T c1 =1.8(1.1 - C)(D)1/2 =1.8(1.1-0.62)(159)^1/2 C I A (0.78)(3.43 IN/HR)(0.16 AC) C I A (0.78)(4.48 IN/HR)(0.16 AC) C I A (0.78)(6.59 IN/HR)(0.16 AC) MIN(S)1/3 (13.27)^1/3 7.44 P100 DTc1 -0.645 7.44(2.5)(5)^(-0.645) 7.44 P2 DTc1-0.645 7.44(1.3)(5)^(-0.645) 7.44 P10 DTc1-0.645 7.44(1.7)(5)^(-0.645) 1.98 = DRAINAGE STUDY CALCULATOR PROPOSED DRAINAGE BASIN 1 DESCRIPTION: C*=(0.90)(%IMP)+CP(1-%IMP) =(0.90)(0.572) + (0.62)(1-0.572) =0.78 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-178 INITIALS:AO DATE:January 31, 2025 Revised 01-15-25 Area =7,840 SF 0.18 AC D =177 ( Watercourse Distance, FT ) S =9.94 ( Slope, % ) PER SDC HYDROLOGY USE 5.00 MIN P 2 =1.3 ( 2-Year, 6-Hour Isopluvial ) P10 =1.7 ( 10-Year, 6-Hour Isopluvial ) P100 =2.5 ( 100-Year, 6-Hour Isopluvial ) I2 ===3.43 IN/HR I10 ===4.48 IN/HR I 100 == =6.59 IN/HR Q2 ===0.41 CFS Q10 ===0.53 CFS Q 100 == =0.78 CFS * Per San Diego County Hydrology Manual 2003 C I A (0.66)(6.59 IN/HR)(0.18 AC) 7.44 P100 DTc1-0.645 7.44(2.5)(5)^(-0.645) C I A (0.66)(3.43 IN/HR)(0.18 AC) C I A (0.66)(4.48 IN/HR)(0.18 AC) MIN(S)1/3 (9.94)^1/3 7.44 P2 DTc1 -0.645 7.44(1.3)(5)^(-0.645) 7.44 P10 DTc1-0.645 7.44(1.7)(5)^(-0.645) 0.66 T c1 =1.8(1.1 - C)(D)1/2 =1.8(1.1-0.34)(177)^1/2 =1.98 DRAINAGE STUDY CALCULATOR PROPOSED DRAINAGE BASIN 2 DESCRIPTION: C*=(0.90)(%IMP)+CP(1-%IMP) =(0.90)(0.141) + (0.34)(1-0.141) = 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-138 INITIALS:AO DATE:January 31, 2025 Reveised 1-15-25 c-imperv calcs c-pervious calcs DESCRIPTION IMPERVIOUS (SF) DESCRIPTION PERVIOUS (SF) TOTAL (SF) Impervious Areas 3751.00 Landscape 6267.00 Σ : 3751.00 Σ : 6267.00 = 10018.00 37%63% IMPERVIOUS AREA CALCULATIONS OFFSITE DRAINAGE BASIN + ** Impervious Areas per Layer **Pervious Areas per Layer: 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com JN:22-138 INITIALS:AO DATE:January 31, 2025 Revised 1-15-25 Area =10,018 SF 0.23 AC D =98 ( Watercourse Distance, FT ) S =3.1 ( Slope, % ) PER SDC HYDROLOGY USE 5.00 MIN P 2 =1.2 ( 2-Year, 6-Hour Isopluvial ) P10 =1.7 ( 10-Year, 6-Hour Isopluvial ) P100 =2.5 ( 100-Year, 6-Hour Isopluvial ) I2 ===3.16 IN/HR I10 ===4.48 IN/HR I 100 ===6.59 IN/HR Q2 ===0.47 CFS Q10 ===0.66 CFS Q 100 ===0.98 CFS *Per San Diego County Hydrology Manual 2003 C I A (0.64)(3.16 IN/HR)(0.23 AC) C I A (0.64)(4.48 IN/HR)(0.23 AC) DRAINAGE STUDY CALCULATOR OFFSITE DRAINAGE BASIN DESCRIPTION: C*=(0.90)(%IMP)+CP(1-%IMP) =(0.90)(0.374) + (0.49)(1-0.374) =0.64 MIN(S)1/3 (3.1)^1/3 7.44 P100 DTc1-0.645 7.44(2.5)(5)^(-0.645) 7.44 P2 DTc1 -0.645 7.44(1.2)(5)^(-0.645) 7.44 P10 DTc1-0.645 7.44(1.7)(5)^(-0.645) 3.85 =T c1 =1.8(1.1 - C)(D)1/2 =1.8(1.1-0.644)(98)^1/2 C I A (0.64)(6.59 IN/HR)(0.23 AC) 171 Saxony Road, Suite 213 • Encinitas, CA 92024 • P: 760-436-0660 • F: 760-436-0659 • info@sampoengineering.com onlinechannel07.php: Critical depth in a circular culvert or pipe Formulas θ = 2 cos-1[1 - 2(y/D)] A = (D2/8) (θ - sinθ) T = D sin(θ/2) V = Q/A (Q2T)/(gA3) = 1 INPUT DATA: Select:SI units (metric) U.S. Customary units Pipe diameter D :2.ft Discharge Q : 0.98 cfs INTERMEDIATE CALCS: Relative depth yc / D: 0.170 Angle θ: 97.53o Flow area A: 0.355 ft2 Top width T: 1.504 ft Froude number F: 1.000 OUTPUT: Critical depth yc: 0.340 ft Critical velocity vc: 2.757 fps Calculate Reset Your request was processed at 08:39:39 pm on February 4th, 2025 [ 250204 20:39:39 ]. Thank you for running onlinechannel_07. Please call again. [140618] ',L.,I r e / 'Y \. ,Y I :1 I l I I I I onlinechannel07.php: Critical depth in a circular culvert or pipe Formulas θ = 2 cos-1[1 - 2(y/D)] A = (D2/8) (θ - sinθ) T = D sin(θ/2) V = Q/A (Q2T)/(gA3) = 1 INPUT DATA: Select:SI units (metric) U.S. Customary units Pipe diameter D :0.5 ft Discharge Q : 0.78 cfs INTERMEDIATE CALCS: Relative depth yc / D: 0.880 Angle θ: 279.0o Flow area A: 0.183 ft2 Top width T: 0.324 ft Froude number F: 1.000 OUTPUT: Critical depth yc: 0.440 ft Critical velocity vc: 4.260 fps Calculate Reset Your request was processed at 04:02:11 pm on February 4th, 2025 [ 250204 16:02:11 ]. Thank you for running onlinechannel_07. Please call again. [140618] 6" DIA. PVC PIPE CAPACITY FOR BASIN 1 ',L.,I r e / 'Y \. ,Y I :1 I l I I I I onlinechannel07.php: Critical depth in a circular culvert or pipe Formulas θ = 2 cos-1[1 - 2(y/D)] A = (D2/8) (θ - sinθ) T = D sin(θ/2) V = Q/A (Q2T)/(gA3) = 1 INPUT DATA: Select:SI units (metric) U.S. Customary units Pipe diameter D :0.5 ft Discharge Q : 0.82 cfs INTERMEDIATE CALCS: Relative depth yc / D: 0.895 Angle θ: 284.6o Flow area A: 0.185 ft2 Top width T: 0.305 ft Froude number F: 1.000 OUTPUT: Critical depth yc: 0.447 ft Critical velocity vc: 4.420 fps Calculate Reset Your request was processed at 04:00:35 pm on February 4th, 2025 [ 250204 16:00:35 ]. Thank you for running onlinechannel_07. Please call again. [140618] 6" DIA. PVC PIPE CAPACITY FOR BASIN NO 2 ',L.,I r e / 'Y \. ,Y I :1 I l I I I I onlinechannel07.php: Critical depth in a circular culvert or pipe Formulas θ = 2 cos-1[1 - 2(y/D)] A = (D2/8) (θ - sinθ) T = D sin(θ/2) V = Q/A (Q2T)/(gA3) = 1 INPUT DATA: Select:SI units (metric) U.S. Customary units Pipe diameter D :0.5 ft Discharge Q : 0.98 cfs INTERMEDIATE CALCS: Relative depth yc / D: 0.940 Angle θ: 303.7o Flow area A: 0.191 ft2 Top width T: 0.235 ft Froude number F: 1.000 OUTPUT: Critical depth yc: 0.470 ft Critical velocity vc: 5.113 fps Calculate Reset Your request was processed at 04:03:04 pm on February 4th, 2025 [ 250204 16:03:04 ]. Thank you for running onlinechannel_07. Please call again. [140618] 6" DIA. PVC PIPE CAPACITY FOR OFFSITE DRAINAGE ',L.,I r e / 'Y \. ,Y I :1 I l I I I I onlinechannel15.php: Discharge in a prismatic channel using the Manning equation Definition sketch for a prismatic channel Formulas: P = b + 2y(1 + z2)1/2 T = b + 2zy A = y(b + zy) R = A/P D = A/T Q = (C/n) AR2/3S1/2 V = Q/A F = V/(gD)1/2 INPUT DATA: Select: SI units (metric) U.S. Customary units Bottom width b: 0 ft Flow depth y: 0.06 ft Side slope z: .04 Manning's n: 0.013 Bottom slope S: .15 INTERMEDIATE CALCS: Units selected: U.S. Customary Gravitational acceleration g: 32.17 ft s-2 Constant C: 1.486 Wetted perimeter P: 0.120 ft Top width T: 0.004 ft Flow area A: 0.000 ft2 Hydraulic radius R: 0.001 ft OUTPUT: Discharge Q: 7.195 cfs Flow velocity V: 0.499 fps Froude number F: 0.508 y b onlinechannel15.php: Discharge in a prismatic channel using the Manning equation Definition sketch for a prismatic channel Formulas: P = b + 2y(1 + z2)1/2 T = b + 2zy A = y(b + zy) R = A/P D = A/T Q = (C/n) AR2/3S1/2 V = Q/A F = V/(gD)1/2 INPUT DATA: Select: SI units (metric) U.S. Customary units Bottom width b: 0 ft Flow depth y: 0.06 ft Side slope z: .04 Manning's n: 0.013 Bottom slope S: .11 INTERMEDIATE CALCS: Units selected: U.S. Customary Gravitational acceleration g: 32.17 ft s-2 Constant C: 1.486 Wetted perimeter P: 0.120 ft Top width T: 0.004 ft Flow area A: 0.000 ft2 Hydraulic radius R: 0.001 ft OUTPUT: Discharge Q: 6.161 cfs Flow velocity V: 0.427 fps Froude number F: 0.435 y b Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/26/2023 Page 1 of 4 36 6 8 5 2 0 36 6 8 5 3 0 36 6 8 5 4 0 36 6 8 5 5 0 36 6 8 5 6 0 36 6 8 5 7 0 36 6 8 5 8 0 36 6 8 5 2 0 36 6 8 5 3 0 36 6 8 5 4 0 36 6 8 5 5 0 36 6 8 5 6 0 36 6 8 5 7 0 36 6 8 5 8 0 469970 469980 469990 470000 470010 470020 470030 470040 470050 470060 470070 469970 469980 469990 470000 470010 470020 470030 470040 470050 470060 470070 33° 9' 20'' N 11 7 ° 1 9 ' 1 9 ' ' W 33° 9' 20'' N 11 7 ° 1 9 ' 1 5 ' ' W 33° 9' 17'' N 11 7 ° 1 9 ' 1 9 ' ' W 33° 9' 17'' N 11 7 ° 1 9 ' 1 5 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 20 40 80 120Feet 0 5 10 20 30Meters Map Scale: 1:502 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. USDA = MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 18, Sep 14, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 14, 2022—Mar 17, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/26/2023 Page 2 of 4USDA = □ D D D D D D D D ,,..,,,. ,,..,,,. □ ■ ■ □ □ ,,..._., t-+-t ~ tllWI ,..,,. ~ • Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI MlC Marina loamy coarse sand, 2 to 9 percent slopes B 0.2 25.0% MlE Marina loamy coarse sand, 9 to 30 percent slopes B 0.5 75.0% Totals for Area of Interest 0.7 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/26/2023 Page 3 of 4USDA = Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—San Diego County Area, California Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/26/2023 Page 4 of 4~ San Diego County Hydrology Manual Date: June 2003 Table 3-1 Section: Page: RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Runoff Coefficient "C" Soil T e NRCS Elements Coun Elements %IMPER. A B Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 Low Density Residential (LOR) Residential, 1.0 DU/ A or less 10 0.27 0.32 Low Density Residential (LOR) Residential, 2.0 DU/ A or less 20 0.34 0.38 Low Density Residential (LOR) Residential, 2.9 DU/ A or less 25 0.38 0.41 Medium Density Residential (MOR) Residential, 4.3 DU/A or less 30 0.41 0.45 Medium Density Residential (MOR) Residential, 7.3 DU/A or less 40 0.48 0.51 Medium Density Residential (MOR) Residential, 10.9 DU/A or less 45 0.52 0.54 Medium Density Residential (MOR) Residential, 14.5 DU/A or less 50 0.55 0.58 High Density Residential (HDR) Residential, 24.0 DU/ A or less 65 0.66 0.67 High Density Residential (HOR) Residential, 43.0 DU/A or less 80 0.76 0.77 Conunercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 Conunercial/lndustrial (G. Com) General Commercial 85 0.80 0.80 Conunercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 Conunercial/lndustrial (Limited I.) Limited Industrial 90 0.83 0.84 Conunercial/Industrial General I. General Industrial 95 0.87 0.87 3 6 of26 C D 0.30 0.35 0.36 0.41 0.42 0.46. 0.45 0.49 0.48 0.52 o._54 0.57 0.57 0.60 0.60 0.63 0.69 0.71 0.78 0.79 0.78 0.79 0.81 0.82 0.84 0.85 0.84 0.85 0.87 0.87 *The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever ( e.g., the area is located in Cleveland National Forest). DU/A= dwelling units per acre NRCS = National Resources Conservation Service SAN DIEGO COUNTY HYDROLOGY MANUAL 0 .0 .0 10. 9 8 7 " .o ,I 0 .0 6. 5 4. " ... .. ~ .. ... ... ~ ' ... ', ~ o, !-. 3. () 2. 0 0 8 7 0.5 0.4 0.3 0.2 0.1 ' . ~ ' ' .· '-J " I 'I l' ... ..... .,,_' I..., .. , ... ..... , .... , • , ... . . ' ' ... , • t--1' ~ ... 'i-, ~i- . ,, ~ . ,, • ... ", ' 5 6 7 8 910 15 .. ' - 20 '"'" I I 30 Minutes 40 50 Duration :::::::I I = I = P5 = I D = 11111111 10011 1111111 """ I EQUATION 7.44 P5 D-0.645 I Intensity (in/hr) 6-Hour Precipitation (in) Duration (min) ttttll11t t:-, ,, "" ........ ' .... "" ... . ' '" .... ... .... . ... ... ' .. ...... ... ' ... " ,. '" .. 1, ... I, ' ', " 2 3 Hours . t1fflitt a - • -I fill! 4 5 6 3.0 2.5 2.0 1.5 1.0 Intensify-Duration Design Chart.• Template Directions for Application: (1) From precipitation maps determine 6 hr and 24 hr amounts for. the selected frequency. These maps are included in the County Hydrology Manual (10, 50, and 100 yr maps included in the Design and Proceduf!i Manual). (2) Adjust 6 hr precipitation (if nees,ssary) so that it is within the range of 45% to 65% of the 24 hr precipitation (not applicaple to Desert). (3) Plot 6 hr precipitation on the right side of the chart. (4) Draw a line through the point parallel to the plotted lines. (5) This line i.s the intensity-dur.;1tion curve for the location being analyzed. Application Form: (a) S,itected fre~uency __ year (b)P5= __ , ;in.,P24= __ ,;:4 = __ %(2) (c) Adjusted P6(2) = __ in. (d) Ix= __ min. (e) I= __ in./hr. Note: Tt)is chart replaces the Intensity-Duration-Frequency curves used since 1965. CGUREI 1 SAN DIEGO COUNTY HYDROLOGY MANUAL EXAMPLE: Given: Watercourse Distance (D) = 70 Feet Slope (s) = 1.310 Runoff Coefficient (C) = 0.41 Overland Flow Time (T) = 9.5 Minutes SOURCE: Airport Drainage, Federal Aviation Administration, 1965 T= 1.8(1.1-C)VD '1/s FIGURE Rational Formula -Overland Time of Flow Nomograph 3-3 You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) I I {. ~ J f> If) Q ' 9 i ~ ~ ..... ..... ..... ..... - ---s-s0 1!l01t--t----t--+-+-+-+--f----+---+-l I :2•-s0 s U'i) s ~ ~ ~ l'i-r-f-r-f-,.,... ,..,. ..,.. ,. 'T 'T -1 j ~ Lr,) ~ v g:, :r l'p <O <.O ..,.. .... ..... ..,.. .,,.. .,,.. ro ~ a::i ..,.. ,2 30' -- t-1--+-+--+--+--+-+-----1-t-+-+--+--+-•~--+--+--+-+-+-+--+--+--+--+-+-t-t----+-ll')-+--+-+---+--+--+--+--+-+-+-+--+----, ■ t-t--+--+--+--+--+-+---+--+--+--+--+-'~ dc----t-+-+--+--+--+-t-----1--+-+--+--+--+-, • <.O <.O ...,. ..... 'T "i 3 County of San Diego Hydrology Manual ,i-~ ~("-; f 4 ,:, ~ q. 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