Granlees Dam (RM 34.5) is operated by Rancho Murieta Community Service District (RMCSD) to supply water to the surrounding community. The dam has two fish ladders, one in each channel. The South ladder was completely rebuilt by the FFC in the summer of 2002 and passes fish effectively at all flows. Passage at the North ladder was observed to be problematic in recent surveys due to excessive jump heights and insufficient energy dissipation in the pools. In the early fall of 2011 reconstruction of the ladder was completed in order to address these problems.
The project modified the fish ladder at the North Granlees Diversion Dam by extending the ladder to create appropriate jump heights between pools and improve upon the existing hydraulic criteria for fish passage. The ladder modification allows fish to pass over a wider range of flows to minimize migration delays and stranding. This project will eliminate the last partial barrier to fish passage on the Cosumnes River and will improve access by fall-run Chinook salmon to 7.2 miles of quality spawning habitat upstream of Granlees Dam.