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HomeMy WebLinkAboutAppendix J - Residential Development Site Preliminary Sewer StudyWalnut & South Highland Ave, Residential Tract Fontana, California APN: 0243-142-01 Preliminary Sewer Study May 22, 2024 Prepared For: Diversified Pacific Communities 10521 Civic Center Drive Rancho Cucamonga, CA 91730 Tel: (909) 481-1150 Prepared By: Allard Engineering 16866 Seville Ave Fontana, CA 92335 Tel: (909) 356-1815 Email: rallard@allardeng.com Prepared under the supervision of: _____________________________________ Raymond J Allard, P.E. RCE 36052 Exp. 06-30-26 16866 Seville Avenue Fontana, CA 92335 (909) 356-1815 * (909) 356-1795 Discussion The purpose of this study is to analyze the expected sewer flow from the proposed 30 Acre development off of Walnut Avenue, west of Almeria Avenue, and analyze the sewer the project tis joining from a capacity standpoint. The site is tributary to an existing 8” sewer in Walnut Avenue that drains to the west and then turns south down a 15” sewer in Beech Avenue. There is also an existing 7 acres in the northeast corner of the site, not a part of this proposed development, which has two homes and is on septic, of which a proposed sewer lateral will stubbed for future tie in. Tributary to the Walnut Sewer is an existing 12 Acre park, 98 Acres of existing single family detached residential, the proposed 30 acre site, and the 17 Acres to the north & northeast of the site, for a total of 157 Acres. Sizing analysis, taken from San Bernardino County sewer criteria, dictates that the sewer needs to handle the peak flow when less than 75% full. According to our sewer capacity analysis (Refer to Table-1 Proposed Sewer Capacity and Velocity Calculation) the segment between MH-A to MH-C in Walnut Avenue from the projects tie in point, to Beechcraft Avenue, the existing 8” sewer main has the capacity for the tributary area of 92 acres which achieved 112% of the half-full capacity (56% full) of the 8” sewer main. The segment between MH-C and MH-D in Walnut Avenue, between Beech Avenue to Beechcraft Avenue (Approximately 960 feet) an upsizing of the existing 8” existing sewer main is required per the sewer capacity analysis (Refer to Table-1 Proposed Sewer Capacity and Velocity Calculation). During this segment the sewer is flowing 87% full after the proposed site is taken into account. A 10” Sewer Main will have the capacity to carry a total wastewater flow of 1.24 CFS (0.80 MGD) from the entire tributary area of 157 acres at its 98% of half full capacity (49% full). Therefore, the proposed upgrade of 8” sewer main into a 10” sewer main will be required for approximately 960 feet from Beach Avenue to Beechcraft Avenue in Walnut Avenue. The proposed 10” sewer main with a flow of 1.24 CFS (0.80 MGD) will be at 98% of its half full capacity (Refer to Table- 1 Propose Sewer Capacity and Velocity Calculation) and will be safe to carry wastewater from the proposed tract. References: Table-1 : Proposed Sewer Capacity/Velocity Calculation In-tract and Sewer Tributary Area Exhibit: Provides all in tract sewer area, and the area tributary to the sewer main. MH #MH # WALNUT AVE A 30 12.9 DU/AC 0.0054 0.0148 0.4428 WALNUT AVE A 7 3.6 DU/AC 0.0015 0.0045 0.0318 WALNUT AVE A B 37 0.4746 0.013 0.67 0.013 0.132354 0.1439 0.03640 3.58 0.70 68 WALNUT AVE B 45 4.7 DU/AC 0.002 0.0059 0.2663 B 10 3.6 DU/AC 0.0015 0.0045 0.0454 WALNUT AVE B C 92 0.7863 0.013 0.67 0.013 0.192907 0.1750 0.06043 4.08 0.70 112 WALNUT AVE C 53 4.7 DU/AC 0.002 0.0059 0.3137 WALNUT AVE C D 145 1.1000 0.013 0.67 0.013 0.251552 0.1955 0.08484 4.39 0.70 157 1.24 89 WALNUT AVE C D 145 1.1000 0.013 0.83 0.013 0.248757 0.1988 0.08483 4.44 1.24 89 WALNUT AVE D 12 COMMUNITY 0.0034 0.0096 0.1157 WALNUT AVE D 15" SEWER 157 1.2158 0.013 0.83 0.013 0.266812 0.2061 0.09318 4.55 0.70 174 1.24 98 Proposed tract density: 12.9 DU/AC n = 0.0013 VCP AR^2/3 3.6 DU/AC = 972 GPD/AC = 0.00097 MGD/AC = 0.0015 CFS/AC = 0.00127 MGD/AC = 0.002 CFS/AC SEWER ANALYSIS, WALNUT AVENUE, FONTANA Sewer Capacity/Velocity Calculations Street Name Segment *Area (AC)Land Cover Average Flow/AC Qa (CFS) Design Flow/AC Qd (CFS) Design Flow (CFS) Comm. Design Flow (CFS) Slope (FT/FT) Diameter (FT) 8" Pipe Capacity (1/2 Full Flow) CFS % Full to 1/2 CapacityR (FT)10" Pipe Capacity % Full to 1/2 Capacity Diameter (FT) Off-tract Area Density: 4.7 DU/AC 1 MGD = 1.55 CFS Qdesign = 1.8 * (Qavg )^0.92 4.7 DU/AC = 1,269 GPD/AC Velocity (FPS) 12.9 DU/AC = 3,483 GPD/AC = 0.00348 MGD/AC = 0.0054 CFS/AC Park Area: 2,200 GPD/AC = 0.0022 MGD/AC = 0.0034 CFS/AC Unit Flow Factor: 270 GPD/DU (Avg Flow) n A (SF) ____________________________________________________________________________ **************************************************************************** HYDRAULIC ELEMENTS - I PROGRAM PACKAGE (C) Copyright 1982-2016 Advanced Engineering Software (aes) Ver. 23.0 Release Date: 07/01/2016 License ID 1400 Analysis prepared by: ---------------------------------------------------------------------------- TIME/DATE OF STUDY: 00:14 05/23/2024 ============================================================================ Problem Descriptions: 8" Dia Sewer Capacity Calc (Half Full) **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.670 FLOWDEPTH(FEET) = 0.335 PIPE SLOPE(FEET/FEET) = 0.0130 MANNINGS FRICTION FACTOR = 0.013000 >>>>> NORMAL DEPTH FLOW(CFS) = 0.70 ============================================================================ NORMAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- NORMAL DEPTH(FEET) = 0.34 FLOW AREA(SQUARE FEET) = 0.18 FLOW TOP-WIDTH(FEET) = 0.670 FLOW PRESSURE + MOMENTUM(POUNDS) = 6.92 FLOW VELOCITY(FEET/SEC.) = 3.960 FLOW VELOCITY HEAD(FEET) = 0.244 HYDRAULIC DEPTH(FEET) = 0.26 FROUDE NUMBER = 1.361 SPECIFIC ENERGY(FEET) = 0.58 ============================================================================ Problem Descriptions: 10" Dia Sewer Capacity Calc (Half Full) **************************************************************************** >>>>PIPEFLOW HYDRAULIC INPUT INFORMATION<<<< ---------------------------------------------------------------------------- PIPE DIAMETER(FEET) = 0.830 FLOWDEPTH(FEET) = 0.415 PIPE SLOPE(FEET/FEET) = 0.0130 MANNINGS FRICTION FACTOR = 0.013000 >>>>> NORMAL DEPTH FLOW(CFS) = 1.24 ============================================================================ NORMAL-DEPTH FLOW INFORMATION: ---------------------------------------------------------------------------- NORMAL DEPTH(FEET) = 0.41 FLOW AREA(SQUARE FEET) = 0.27 FLOW TOP-WIDTH(FEET) = 0.830 FLOW PRESSURE + MOMENTUM(POUNDS) = 13.91 FLOW VELOCITY(FEET/SEC.) = 4.568 FLOW VELOCITY HEAD(FEET) = 0.324 HYDRAULIC DEPTH(FEET) = 0.33 FROUDE NUMBER = 1.410 SPECIFIC ENERGY(FEET) = 0.74 1 Untitled Map Write a description for your map. 1000 ft N ➤➤ N Image © 2023 Airbus Image © 2023 Airbus Image © 2023 Airbus