|
elfeWSMIn
<br /> City of Pleasanton I Water Shortage Contingency Plan £--\ .-'rLTO\
<br /> • Special Water Feature Distinction (Section 11): Defines considerations and definitions for water
<br /> use for decorative features versus pools and spas.
<br /> The WSCP has been prepared in general accordance with the format suggested by the California
<br /> Department of Water Resources(DWR) in the 2025 UWMP Guidebook and incorporates standardized
<br /> DWR 2025 UWMP tables for WSCPs, consistent with the UWMP Act and CWC§10644(a)(2),which states:
<br /> "The plan, or amendments to the plan, submitted to the department ... shall include any
<br /> standardized forms,tables, or displays specified by the department".
<br /> In addition,tables and figures beyond DWR's standard set are included as appropriate to provide further
<br /> context.To distinguish content related to DWR's standardized tables,the companion DWR table number
<br /> is included in table titles throughout the Plan for accessible cross-reference.
<br /> 1 WATER SUPPLY RELIABILITY ANALYSIS
<br /> Per CWC§10635(a-b),as part of UWMPs, every urban water supplier in California is required to assess the
<br /> reliability of its water service to its customers during normal, dry, and multiple dry water years. The
<br /> assessment compares the total water supply sources available to the supplier with the long-term total
<br /> projected water use over the next 20 years, in five-year increments,for a normal water year, a single dry
<br /> water year, and a drought lasting five consecutive water years. Additionally, suppliers are required to
<br /> address supply risks under a severe near-term drought period (i.e., 2026-2030) as a Drought Reliability
<br /> Assessment(DRA). Both the near-term DRA and long-term supply reliability assessment consider plausible
<br /> hydrological and regulatory variability, infrastructure capacity, climate conditions, and other factors that
<br /> affect water supply and demand.
<br /> Sections 6 and 7 of the City's 2025 UWMP present the City's water supply sources and reliability,
<br /> respectively. For potable supply, Pleasanton currently relies exclusively on Zone 7 Water Agency(Zone 7),
<br /> the Tri-Valley's regional wholesale water supplier.Thus,the City's water supply reliability is fundamentally
<br /> linked to Zone 7's. For Zone 7, a water shortage condition occurs when the available supply of potable
<br /> water cannot meet its retailers' water demands for human consumption, sanitation,fire protection, and
<br /> other beneficial uses. Besides the City, Zone 7's retailers include California Water Service-Livermore
<br /> District,the City of Livermore (Livermore), and Dublin San Ramon Services District (DSRSD).
<br /> Zone 7's 2025 UWMP indicates the ability to meet retailer demands during five-year droughts in 2030,
<br /> 2035, and 2040. However, beginning in 2045, Zone 7 is projecting a 14% shortfall for the last year of a
<br /> drought lasting five consecutive water years. Because the City anticipates the ability to access its full
<br /> groundwater pumping quota (GPQ) of 3,500 acre-feet per year (AFY) will be restored through the Joint
<br /> Groundwater Project,the assessment of future water supply reliability assumes that the City will rely upon
<br /> groundwater to meet 3,500 AFY of its potable demands in each year of a five-year drought through 2045
<br /> and that the remaining balance will be met through Zone 7 supply purchases. For the fifth year of a five-
<br /> year drought in 2045, the projected 14% reduction in Zone 7 supply availability translates to a 10%
<br /> shortfall for the City.
<br /> The analysis associated with this WSCP was developed in the context of Zone 7's water supply sources
<br /> and reliability. In some cases,the City and Zone 7 may be able to foresee a water shortage, but the water
<br /> shortage may also be caused by an unforeseen sudden or emergency event. Statewide water supply
<br /> conditions, changes in groundwater levels, and actions by other agencies may impact Zone 7's available
<br /> water supply. In general, Zone 7's water supply conditions may be affected by the following:
<br /> • State Water Project(SWP)supply allocations and storage levels;
<br /> • Vulnerability of the Sacramento-San Joaquin Delta to seismic events, changing
<br /> environmental and regulatory requirements, and climate change; and
<br /> ekienvironment Public Draft I May 2026
<br /> &water 2 EKI Environment&Water, Inc.
<br />
|