2025 Urban Water Management Plan

Section 6 2025 Urban Water Management Plan Water Supply Characterization City of Pleasanton Public Draft | May 2026 6-27 EKI Environment & Water, Inc. add the two proposed DCP diversion intakes to the SWP’s water rights. In October 2025, DWR certified that DCP is consistent with the Delta Plan. DWR is continuing with design refinements, environmental planning and permitting through 2026-27, including resolving appeals on its Delta Plan certification. DCP will potentially be operational in 2045 following extensive planning, permitting and construction. DWR estimates of SWP supply reliability in the Draft 2025 DCR are based on existing facilities and do not include the proposed DCP. Since this UWMP uses DWR’s Draft 2025 DCR to estimate SWP supplies at 2043, any changes in SWP reliability resulting from the proposed DCP are not included in this UWMP. Most recent DWR estimates indicate that the DCP is expected to increase SWP Delta exports by about 467,000 AFY on a long-term average under current climate conditions. The Zone 7 Board has approved funding and participation in planning, permitting, and other pre- construction work of the DCP through 2027. The Zone 7 Board has not yet decided whether to participate in construction of the project. For planning purposes, the 2025 UWMP does not include DCP, since it is expected to come online around 2045, near the end of Zone 7’s future planning period. Continued participation by Zone 7 in the planning efforts will allow Zone 7 to elect to participate in the DCP implementation in the future based on information developed in the planning process, allow access by Zone 7 to information related to benefits and costs, and provide Zone 7 influence throughout the process. The work over the next two to four years will inform the Zone 7 Board’s decision-making as the DCP continues to advance. 6.8.1.2 Potable Reuse Potable reuse involves advanced treatment of recycled water to produce purified water to supplement potable water supplies. Though Zone 7 does not currently have a potable reuse project planned, Zone 7 and its three other Tri-Valley retailers are evaluating this option as a potential source of new supply. While recycled water for non-potable uses (e.g., irrigation) has been available for many years in the Tri-Valley, potable reuse would be a new use of local wastewater resources collected by DSRSD and Livermore, if implemented. Its main benefits include local production and control, drought-resilient supply, and resource recovery. Although Zone 7 does not provide recycled water, its retailers have provided recycled water service for many years. Initiating potable reuse in the Tri-Valley would involve a partnership between Zone 7 and its participating retailers to manage the wastewater collection and treatment, and purified water production and distribution/storage. Local wastewater resources would be collected by DSRSD and/or Livermore and treated to meet drinking water standards. Following treatment, potential purified water uses could include: 1) groundwater augmentation or recharge, 2) storage in the COLs, and/or 3) raw water augmentation to Zone 7’s Del Valle Water Treatment Plant (DVWTP). Zone 7 collaborated with Tri-Valley retailers to develop the Joint Tri-Valley Potable Reuse Feasibility Study in 2018, which evaluated the feasibility of potable reuse in the Tri-Valley. An updated study may be developed in upcoming years. Zone 7 also participated with ACWD, Livermore, DSRSD, LAVWMA, and Union Sanitary District on a project which developed outreach materials in 2025 to support purified water awareness. This 2025 UWMP does not include potable reuse as a future supply for the City and does not assume potable reuse to be part of Zone 7’s supply portfolio. 6.8.1.3 Sites Reservoir Sites Reservoir is a proposed new 1,500,000 AF off-stream storage reservoir in northern California near Maxwell. Sacramento River flows will be diverted during excess flow periods and stored in the off-stream reservoir and released for use in the drier periods. Shown in Figure 6-5, Sites Reservoir is expected to