Tuolumne River Partners Launch Next Habitat Restoration Project by Modesto Irrigation District, Turlock Irrigation District, San Francisco Public Utilities Commission Sep 1, 2026 Member Submitted News As part of a continued commitment to restoring and enhancing habitat for native fish, Tuolumne River Partners Modesto Irrigation District (MID), Turlock Irrigation District (TID) and the San Francisco Public Utilities Commission (SFPUC), in partnership with the U.S. Fish and Wildlife Service (USFWS), have begun construction on the Powerhouse Riffles Restoration Project, a mainstem Tuolumne River restoration effort designed to improve spawning and rearing habitat for salmon and other native aquatic species. The approximately $4.7 million, self-funded project will restore spawning habitat impacted during high river flow events in 1997, 2011 and 2017 by reconstructing riffles and gravel bars and enhancing in-channel habitat complexity and diversity. Riffles are shallow, fast-moving sections of a river where the water flows over a cobble or gravel bed, creating a choppy surface. Riffles are key habitats for salmon: the churning water traps air and raises oxygen levels in the river, rocks and gravel attract aquatic insects, and juvenile fish gather in riffles to eat the abundant insects and lay their eggs in the clean gravel. The Powerhouse Riffles Restoration Project will add approximately 25,000 cubic yards of spawning gravel, creating 4.8 acres of new gravel features and restoring approximately 2,400 feet of the Lower Tuolumne River. Coarse sediment mixtures have been carefully selected to maintain channel complexity while allowing the river to naturally evolve. In addition to new spawning habitat, crews will install approximately 50 large pieces of woody debris throughout the project area to promote channel complexity, improve sediment sorting and provide juvenile fish refuge from predators. Approximately 80 strategically placed boulders will also be added at the downstream ends of select riffles to create improved feeding areas for fish. This in-water work is expected to be completed in October 2026. “We continue to invest in science-based solutions to improve habitat and support healthy fish populations in the Tuolumne River,” said TID General Manager Brad Koehn. “We’re building on the success of our previous restoration efforts, and this project is another important step in the investment and early implementation of our comprehensive habitat restoration program.” The Powerhouse Riffles Restoration Project is one of many restoration efforts planned as part of the Tuolumne partners’ historic, self-funded $80 million commitment to design and implement a collaborative, holistic habitat restoration program along the Lower Tuolumne River through the Healthy Rivers and Landscapes Program and a collaborative memorandum of understanding with USFWS. River Partners, a renowned California riverway restoration organization, leads the Tuolumne River Partners’ multidisciplinary team of biologists, ecologists and other technical experts, including Applied River Sciences, which designed and is leading implementation of the Powerhouse Riffles Restoration Project. Ford Construction is performing construction activities, which kicked off in July and are expected to be completed in October. Stantec is providing environmental monitoring services. The Tuolumne River Partners are working with the Chicken Ranch Rancheria of Me-Wuk Indians of California and the Northern Valley Yokuts/Ohlone tribe to ensure that tribal monitors have an opportunity to inspect any ground disturbing work and to ensure that known or discovered sites of tribal significance are protected. This same team of project partners were instrumental in the construction and completion of the Tuolumne River Partners’ successful Old La Grange Bridge Habitat Restoration Project in 2024. “Each restoration project contributes to a vibrant and healthier Tuolumne River,” said SFPUC General Manager Dennis Herrera. “Through science, collaboration and long-term investments, we’re creating better habitat for native fish and delivering lasting benefits for the river and the communities and wildlife that depend on it.” As part of the Healthy Rivers and Landscapes Program, MID, TID and the SFPUC have joined dozens of other California water agencies committed to collaborating with the State of California to advance agreements that will provide water supply reliability to our communities while enhancing river ecosystems. “We’re adding to what we’ve learned about the river and how fish respond to habitat improvements. This work reflects our longstanding commitment to responsible stewardship and science-based management of the Tuolumne River,” said MID General Manager Jimi Netniss. “By restoring spawning and rearing habitat today, we’re helping create a healthier river ecosystem that will support native fish populations well into the future.” By 2030, with the help of experts River Partners and Applied River Sciences, the Tuolumne River Partners aim to develop 77 acres of suitable salmon floodplain rearing habitat and add approximately 100,000 tons of gravel in specific reaches of the river for optimal salmon spawning and rearing. To learn more about the Tuolumne River Partners’ stewardship efforts, please visit tuolumneriverpartners.com.
