MWD targets fall 2026 design approval for phased Pure Water Southern California reuse project

MWD targets fall 2026 design approval for phased Pure Water Southern California reuse projectFollowing the certification of the project's environmental impact report, MWD will utilize a collaborative delivery framework for the initial stage of the 150 MGD potable reuse program, delaying final construction commitments until a guaranteed maximum price is established.

MWD plans to ask its board to approve design activities for the initial stage of the Pure Water program by September 2026.

The district will use a collaborative delivery approach, requiring the contractor to provide a guaranteed maximum price (GMP) at 60% to 90% design completion.

The initial design phase will cover either a 45 MGD or 75 MGD capacity stage, dictating whether two or eight pipeline reaches are designed.

West Basin Municipal Water District is concurrently coordinating with the Water Replenishment District on potential inland injection wells near Torrance to maximize the new reuse supplies.

The Metropolitan Water District of Southern California (MWD) is advancing its Pure Water Southern California (PWSC) program toward the design phase, adopting an incremental, progressive design-build strategy to secure price certainty before committing to full construction. Gloria Lai-Bluml, an MWD program manager, outlined the implementation timeline during a May 6, 2026, West Basin Municipal Water District caucus meeting. The update follows the MWD board's certification of the project's final Environmental Impact Report (EIR) in February 2026 and the unanimous approval of the project's biennial budget in April. Staff plan to ask the MWD board to approve starting design for the initial stage of the project in the fall of 2026, likely around September. Under the collaborative delivery approach, the selected design-builder will advance the design to an undetermined threshold—potentially 60% or 90%—before submitting a Guaranteed Maximum Price (GMP) for construction. Lai-Bluml noted that this method provides the district with price certainty and an "off-ramp" if the board decides not to proceed with construction, effectively pushing the final construction approval out by two to three years. The initial design effort will scale based on the selected starting capacity. If a 45 MGD capacity is chosen, the design will cover two pipeline reaches. If the district opts for a 75 MGD initial capacity, the scope will expand to eight pipeline reaches. The full build-out of the PWSC program is ultimately envisioned at 150 MGD, incorporating both indirect and direct potable reuse (DPR) via raw or treated water augmentation. The procurement process for the design-build contract is expected to take six to nine months once authorized. In the interim, MWD will hold a DPR implementation strategy workshop on June 23, 2026, and expects to finalize an agreement with the Los Angeles County Sanitation Districts in the fall. Concurrently, regional partners are preparing for the new water supplies. West Basin is working with the Water Replenishment District (WRD) on modeling potential inland injection wells in the Torrance area to maximize the use of the recycled water, pending MWD's final decisions on the PWSC pipeline routing and deliveries.