Thursday September 3, 2026
MID —
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.