14 ATTACHMENT 1 EXHIBIT A - Laserfiche WebLink

THE CITY OF Chapter 7.: , _, � .. Water Service Reliability and Drought Risk Assessment PL£ASANTON 7.1.4 Water Management Tools and Options The City and Zone 7 coordinate to increase regional supply reliability and reduce reliance on water imports. The City focuses on demand reduction, specifically prioritizing water conservation and encouraging recycled water use. Zone 7 supports these efforts by the City while also evaluating new supply options (including potable reuse and brackish water desalination) and optimizing and expanding local storage. In addition, Zone 7 is a member of the Bay Area Regional Reliability (BARR) partnership, which brings together eight Bay Area water agencies to improve regional water supply reliability. Besides Zone 7, these agencies include ACWD, SFPUC, the Bay Area Water Supply and Conservation Agency (BAWSCA), CCWD, EBMUD, Marin Municipal Water District (MMWD), and VW. The BARR partners have agreed to work cooperatively to address water supply reliability concerns and drought preparedness on a mutually beneficial and regionally focused basis. Near- and long-term joint water supply reliability projects may be evaluated through BARR, such as use of the capacity of existing facilities, changes to infrastructure (including new interties, recycled water, water conservation, expanded treatment, regional desalination, and water transfers and exchanges), and other projects or institutional arrangements that encourage a regional approach to achieving water supply reliability in the Bay Area. As part of its existing CIP, Zone 7 is planning to construct a reliability intertie with another major water agency (e.g., EBMUD or SFPUC) to help mitigate some of the risk during a major water supply interruption from the Delta and to create opportunities for transfers/exchanges. This intertie could allow Zone 7 to acquire emergency water supplies to help meet minimum health and safety water supply needs during a major Delta outage, assuming the partnering agency has available supply and the transmission capacity available during the emergency period. A conceptual 24- to 30 -inch diameter intertie with EBMUD could connect to the west side of Zone 7's transmission system and convey up to 10 to 15 MGD of supply. Additional wells would also increase access to local groundwater and improve its management, while a new booster pump station would improve conveyance of groundwater across the Tri -Valley. The new Chain of Lakes Pipeline would allow for access to water stored locally in the Chain of Lakes. 7.2 DROUGHT RISK ASSESSMENT In accordance with CWC Section 10612, urban water suppliers must conduct a DRA, which evaluates the risk of a severe drought occurring for the next five consecutive years (2021-2025). Supply conditions for the DRA are based on the five driest consecutive years on record, with adjustments to consider plausible changes in climate, regulations, and other locally applicable criteria. This section reviews the data and methods used to define the DRA water shortage condition and evaluates each water source's reliability under the proposed drought condition. Finally, total water supplies during the five-year drought are compared to projected demands, accounting for any applicable supply augmentation or demand reduction measures available to the City. 7.2.1 Data, Methods, and Basis for Water Shortage Condition The water shortage condition for the DRA is the same as the five-year drought presented in Section 7.1.2. Since the DRA can be updated outside of the five-year UWMP cycle, a summary of the data and basis for the water shortage condition is provided in this section. WEST YOST 7-11 City of Pleasanton 2020 Urban Water Management Plan May 2021