2025 Urban Water Management Plan

Section 7 2025 Urban Water Management Plan Water Supply Reliability Assessment City of Pleasanton Public Draft | May 2026 7-12 EKI Environment & Water, Inc. 7.3 Supply and Demand Assessment This section presents comparisons of projected water supplies and demands from 2025 through 2045 under the following hydrologic conditions: normal year, single dry year, and five consecutive dry years. The City’s projected demands are presented in Section 4, while supply sources are described in Section 6. Unless otherwise noted, it is assumed demand projections will not change with hydrologic conditions. In other words, demands are assumed to be unconstrained unless they are limited by available supplies. 7.3.1 Normal Year Supply and Demand Assessment The City’s normal year supplies include: • Purchased supplies from Zone 7 • 3,500 AFY of groundwater pumped by the City from the Main Basin • Up to 1,340 AFY of recycled water Based on the reliability assessment in the 2025 UWMP, Zone 7 predicts they can meet all retailer demands during a normal year. Therefore, Table 7-4 shows that in normal years the City’s supplies are adequate to meet projected demands. The supply and demand totals are consistent with those in Table 6-11 and Table 4-5, respectively. Table 7-4 Normal Year Supply and Demand Comparison (DWR Table 7-2) 2030 2035 2040 2045 (AF) (AF) (AF) (AF) Supply totals (from DWR Table 6-9) 16,401 17,288 18,178 19,172 Use totals (from DWR Table 4-2) 16,401 17,288 18,178 19,172 Surplus/(shortfall) 0 0 0 0 7.3.2 Single-Dry Year Supply and Demand Assessment In Chapter 7 of its 2025 UWMP, Zone 7 has indicated it can meet retailer demands during single dry years through 2045. Therefore, Zone 7 supplies to the City are assumed to equal the City’s projected potable water demands after accounting for the City’s GPQ. Recycled water supply is assumed to be unaffected by the dry conditions. Table 7-5 shows that the City’s supplies are adequate to meet projected demands during single dry years.  CWC §10635(a) Every urban water supplier shall include, as part of its urban water management plan, an assessment of the reliability of its water service to its customers during normal, dry, and multiple dry water years. This water supply and demand assessment shall compare the total water supply sources available to the water supplier with the long-term total projected water use over the next 20 years, in five-year increments, for a normal water year, a single dry water year, and a drought lasting five consecutive water years. The water service reliability assessment shall be based upon the information compiled pursuant to Section 10631, including available data from state, regional, or local agency population projections within the service area of the urban water supplier.