Local irrigation districts will hold a workshop on Wednesday to discuss fish passage in the Tuolumne River as part of the La Grange Dam licensing process.
The Turlock Irrigation District and Modesto Irrigation District jointly constructed the La Grange Dam between 1891 and 1893 to raise the height of the Tuolumne River to a level that would enable them to divert and deliver water by gravity flow to their irrigation canals, located on opposite sides of the river. In 1924, Turlock Irrigation District built a two-unit powerhouse on the south bank of the Tuolumne River, which it has continued to own and operate for power generation.
In June 2011, the National Marine Fisheries Service asked FERC to review the La Grange Project because it lacks fish passage facilities and therefore blocks the movement of migrating fish to parts of the Tuolumne River upstream of the La Grange Dam. Conservation groups have argued that Chinook salmon and Central Valley steelhead populations in the San Joaquin River basin have experienced dramatic declines in recent years, and overall declines since the original Don Pedro Project was licensed.
Despite arguments from TID and MID, in December 2012 FERC issued an order finding that the La Grange Hydroelectric Project requires licensing because it is located on a navigable river.
As part of a fish passage study for the licensing process, TID and MID are holding a series of public workshops to discuss upstream and downstream fish passage facilities considerations, including determining what species, why/if passage is necessary, and if necessary, how it could be done and recognizing other uses in the river.
If the Districts are required to build fish passage facilities, which could be a substantial investment, the cost could ultimately be borne by TID and MID ratepayers, according to TID.
At Wednesday's workshop, TID and MID will also be asking representatives of federal and state agencies to describe their management goals that led to the request for studying fish passage.
The fish passage workshop will be held from 9 a.m. to noon Wednesday in the second floor multipurpose room of the Modesto Irrigation District, 1231 11st St., in Modesto.