Ribbon cutting marks completion of $33M Horsethief Canyon Water Reclamation Facility expansion
by: EVMWD
Published: March 4, 2026
TEMESCAL VALLEY...Elsinore Valley Municipal Water District (EVMWD) recently celebrated a major milestone with the ribbon-cutting and valve-turning ceremony for the upgraded and expanded Horsethief Canyon Water Reclamation Facility (HTCWRF). More than 60 community members, regional partners, and developers attended the event, which marked the completion of a $33 million investment in Temescal Valley's future.
The upgraded HTCWRF expands treatment capacity from 0.5 to 0.8 million gallons per day (MGD), providing wastewater service for approximately 1,200 homes. As residential and commercial development continues to accelerate across the region, the expanded facility positions the district to meet growing demand while maintaining reliable, efficient service, reflecting EVMWD's commitment to keeping pace with Temescal Valley's rapid growth.
The project represents several important firsts for EVMWD. It was the District's first design-build project, delivered successfully despite COVID-era supply chain challenges that impacted projects across the industry. It also reflects the power of public-private partnership: through collaboration with four regional developers, 65% of the total project cost was privately funded, a landmark outcome that reduced the financial impact on existing customers while advancing critical infrastructure.
"Projects like Horsethief Canyon demonstrate what is possible when innovation, stewardship, and collaboration come together," said EVMWD General Manager Greg Thomas. "This facility reflects our commitment to responsible infrastructure planning — delivering lasting value for our customers and our community."
The new facility employs membrane bioreactor (MBR) treatment technology, which integrates membrane filtration with biological treatment processes for nutrient removal. This approach delivers superior effluent quality in a compact footprint at reduced capital and energy costs. The facility is also designed to be operator-friendly, leveraging automation for convenient, remote monitoring. Importantly, the high-quality effluent produced is suitable for non-potable reuse applications such as local landscape irrigation or groundwater recharge, a particularly valuable capability in water-scarce Southern California.
Carollo Engineers was retained by EVMWD to provide program management and owner's advisor services throughout the project, from design through construction, as part of the District's broader water reclamation expansion program. The program also encompasses significant upgrades and expansion of the Regional Water Reclamation Facility, increasing its treatment capacity from 8 to 12 MGD, where Carollo continues to serve as program manager and owner’s advisor.
"What EVMWD accomplished here is remarkable — bringing together four private development partners, embracing a new project delivery model, and seeing it through despite significant supply chain challenges," said Carollo Senior Project Manager and Vice President Jeff Weishaar. "The Horsethief Canyon WRF expansion is a testament to what thoughtful program management and strong partnerships can achieve, delivering resilient, future-ready water systems for the Temescal Valley community."
The ribbon-cutting ceremony drew representatives from federal, state, and local offices, who presented certificates recognizing the milestone. Attendees included representatives from the offices of Congressman Ken Calvert, Senator Kelly Seyarto, and Assemblywoman Sabrina Cervantes, among others. Guests were invited to tour the facility following the ceremony to see firsthand how the improvements will support community-centered water management for future generations.
Photo:EVMWD