AgdaPkt 2002-08-26 - Laserfiche WebLink

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Executive Summary This project develops base water use forecasts for the City of Redwood City (RWC) for the period 2000 to 2020. The forecasts can be used for a variety of water planning activities including: · Assessing the merits of an expanded recycled water system in Redwood Shores and subsequent proposed phases in other areas · Updating elements of RWC's Urban Water Management Plan · Establishing a continuing nexus between water supply planning and RWC's General Plan · Developing base water use characteristics for potential rates and charges. The water use forecasts are comprised of seven separate forecasts made for the following user sectors: single family, multiple family, commercial, commercial irrigation, municipal, other, and residential irrigation. The forecasts made for each of these sectors make use of forecasts of key data drivers. The data drivers are number of housing units for the residential sectors, number of employees for the commercial sectors, and population for the other sectors. These data drivers are multiplied by water use coefficients, based on historical water use correlations, to obtain the water use forecasts. Results are summarized in Exhibits 1 and 2. Holding other factors constant, total water use is expected to increase from 13,170 acre-feet per year (AFY) in 2000 to 15,520 AFY in 2020. This is a 17.8% increase over the 20 years that translates into an annual average 0.82 percent increase. Factoring in passive water conservation from natural replacement of toilets and clothes washers with more efficient technologies decreases the 2020 forecast by 703 AFY to 14,817 AFY. This translates into a 0.59 annual average increase over the 20 years. Exhibit 1. Base Water Use Forecast in Acre-Feet per Year (AFY) Actual Forecast Year Description 2000 2005 2010 2015 2020 Existing Customers 12,596 12,596 12,596 12,596 12,596 New Customers 0 513 1,386 1,962 2,328 New and Existing Customers 12,596 13,109 13,981 14,558 14,923 Unaccounted for Water 574 524 559 582 597 Total without Conservation 13,170 13,633 14,541 15,140 15,520 Total with Passive Conservation 13,170 13,467 14,191 14,590 14,817 The base water use forecasts do not factor in additional water savings that could be achieved through active water conservation programs. RWC's Urban Water Management Plan addresses potential savings from water conservation "Best Management Practices" (BMPs). The forecasts generated here are used as the base case scenario for that plan. The 0.59 rate of future growth in water use is less than that experienced by RWC in the past. From 1975 to 2000, the annual average rate of growth was 1.3 percent, largely a Page 1