This project improved fish passage at the Central California Traction Railroad Crossing on the Stockton Diverting Canal, within the lower Calaveras River system near Stockton in San Joaquin County. A second flume, notches, and a downstream roughened rock ramp were installed to provide passage at flows between 30 and 1,000 cfs. The project opened approximately 13.4 miles of stream to fall-run Chinook salmon and Central Valley steelhead — a core recovery population in the Southern Sierra and San Joaquin watershed.
Location: The Central California Traction Railroad Crossing is located on the Stockton Diverting Canal,a channel within the lower Calaveras River system near the city of Stockton, which flows to the San Joaquin River and ultimately the Sacramento-San Joaquin Delta, draining a watershed of approximately 470 square miles.
Historical Presence of Anadromous Fish: The Calaveras River is in the range of historical and essential fish habitat for fall-run Chinook salmon and part of the historical distribution for Central Valley steelhead. Historical records document Chinook salmon runs in the Calaveras dating to the 19th century, with multiple run types using the river before New Hogan Dam was completed in 1963. Today, the Calaveras River supports a small but important rainbow trout and steelhead population, and Chinook salmon opportunistically migrate into the Calaveras to spawn during high rainfall years when sufficient flows allow access to habitat. The recovery plan for Central Valley steelhead identifies the Calaveras River as a core population in the Southern Sierra and San Joaquin watershed essential to species recovery.
Project Lead Organization: Stockton East Water District (SEWD)
Project Partners: U.S. Fish and Wildlife Service (USFWS); California Department of Water Resources (DWR); California Department of Fish and Wildlife (CDFW); Central California Traction Rail Company; California Fish Passage Forum; Central Valley Flood Protection Board; Ridgeline Engineering (structural evaluation).
Funding from the California Fish Passage Forum: $40,000
Project Description: The CCTRC on the Stockton Diverting Canal was identified in the 2007 Calaveras River Fish Migration Barriers Assessment Report as an impediment to migratory fish at certain flows. The railroad crossing structure created a barrier to adult and juvenile Chinook salmon and Central Valley steelhead when canal flows dropped below critical thresholds. The project installed a second flume with upstream wing walls, two new notches, and a roughened channel (rock ramp) downstream of the crossing, providing improved passage at flows at or above 30 cfs and up to 1,000 cfs. The project underwent an unusually lengthy permitting process spanning from 2013 to 2019 due to slow regulatory agency processing.
Expected Completion: Fall 2019Project Effectiveness: The project opened up approximately 13.4 miles of stream to salmon and steelhead. The project was accepted by the Central Valley Flood Protection Board and a final structural evaluation by Ridgeline Engineering confirmed no structural impacts to the existing bridge. At peak post-construction flows of approximately 35 cfs, the improvements appeared to be functioning as intended. Life-cycle monitoring for Chinook salmon and steelhead was planned as the primary success metric going forward.