AgdaPkt 2003-09-08 - Laserfiche WebLink

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RWC Water Sapply RdLabinty 3. Reliability: The water supply And Demand Balance Comparing the water supply data shown in Exhibit I with the demand data shown in Exhibit 2, it is obvious that RWC is in a high risk, low reliability situation it the momem RWC has one of the lowest levels of reliability of the BAWUA members, l also believe RWC has one of the lowest levels of water supply reliability in Northern California, although obtaining accurate measures of reliability is difficult. As a consequence, I have not collected benchmarks for comparison at this time. The SFPUC water supply situation will remain unchanged until at least July 2009 when the existing Master Water Sales Contract and BAWUA / SFPUC Interim Shortage Allocation Plan expire and are reuegodated. It is difficult to predict the outcome of the renegotiations, but it is unlikely that RWC will improve its water supply reliability from this source. 4. Selecting A Proper Level Of RellabiHty What is the appropriate level of reliability! There is no exact engineering answer, but rather the appropriate level is a judgment call dependent on the level of risk RWC is willing to take, and how much RWC is willing to pay to minimize this risk. Exhibit 3 graphically shows how water supply reliability increases with water supply additions of 1,000 AFY for water conservation and an additional 1,208 for water recycling (priority customers 1 and 2 in the Redwood Shores area identified byKennedy/Jenks Consultants, Water Recycling Feasibility SrudyjorRedwood City, August 2002). Focusing on scenario 3 (SFPUC cutback of 10 RWC's cutback under current arrangements would be 17.5 %. If 1,000 AFY of additional supplies could be obtained via conservation, the cutback would be reduced to 12.4%. With 1,208 AFY of additional supplies from recycling (2 AFY total), the cutback would be a very manageable 6.3%. Readers should note that the reliabilities presented are for existing water customers as of FY 200012001. As shown in Exhibit2, water use is expected to grow 1,647 AFY over the next 20 years. The thirst of this new growth needs to be quenched from new water supplies if the water reliability of existing customers is not to decay incrementally. Post