Reso 2009-115 - Laserfiche WebLink

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City of San Leandro Sewer System Management Plan Volume I Flow Allotments Based on the City's design standards, initial projected flows are "injected" into the hydraulic model. These are allocated based on the individual parcels to represent geographic regions that inject flows to particular pipes along the system. Each parcel is associated with its respective land use designated as one of three distinct types of sanitary service areas: residential, commercial, or open space/parkland. Residential areas generate flows based on population. For design purposes, the average family unit is considered 3.5 persons who generate 90 gallons per person per day for a total of 315 gallons per parcel per day. The commercial areas generate flows based on volume. Typically the total commercial water consumption is summed from the latest report and proportioned to each parcel by acreage in gallons per day. The open space/parkland areas are assumed to generate no sanitary flow. These areas are assigned to specific pipes in the collection system. The sanitary flows are injected into the system throughout a 24-hour day based on flow study diurnal curves for each type of use. Diurnal curves were derived from two flow monitoring areas of the flow study: one a predominantly residential area and another predominantly commercial area. Since no flow is generated for open space/parkland areas, a third diurnal curve is not needed. Once completed, the initial flow data is adjusted to the results of the flow metering and monitoring study and the allocation of GWI, BSF & RDUI to the sub-basins. BSF and GWI values are calibrated to the metered values found during dry weather periods. Results of this analysis provide the loading parameters for present and future runs of the capacity model. Capital Improvement Program (CIP) The CIP process includes a system for preparing, evaluating, and reporting the CIP budgets. The City's collection system requires a continuing number of improvements including collection system capacity upgrades, correcting structural problems, and modifications to pump stations and the treatment plant. A construction schedule for the capital projects is developed based on the project priorities and to support payment of all capital improvement program and equipment replacement expenditures. CIP Planning The CIP includes increases in pipe size, UI reduction programs, increases and redundancy in pumping capacity, and storage facilities. The City has put into place the steps needed to establish a short-and long-term CIP to address identified hydraulic deficiencies, including prioritization, alternatives analysis, and schedules. The City has prepared and is implementing a Capital Improvement Program (CIP) that will provide hydraulic capacity of key sanitary sewer system elements for dry weather peak flow p~~~ ~ z~