The Soquel Avenue Bridge spans across the San Lorenzo River. Photo © Coastal Watershed Council.

The San Lorenzo River was once home to very large numbers of coho salmon and steelhead trout. Tourists from across the state visited Santa Cruz to fish in downstream fishing holes. Many residents relied on healthy fish stocks for their livelihoods.

A Fishy Situation

Today, under the federal Endangered Species Act, coho salmon are listed as a federally endangered, steelhead are listed as threatened, and the San Lorenzo River is listed as critical habitat. Coho have not been seen in the San Lorenzo River for almost 20 years and though steelhead still come to the San Lorenzo from the Pacific to spawn, their numbers have been greatly reduced.

Plentiful steelhead trout and coho salmon attract fishermen from across the state to the San Lorenzo River. Photo courtesy and ©of Santa Cruz Public Libraries. — Plentiful steelhead trout and coho salmon attract fishermen from across the state to the San Lorenzo River. Photo courtesy of and © Santa Cruz Public Libraries.

Sedimentation, from very fine sediments like clay and silt to coarser sediments like gravel, is seen as a major threat to these fish. The San Lorenzo River faces heavy inputs of fine sediments because of the erosive nature of the upstream mountains. These sediments have been shown to decrease survival of salmonid eggs. If the eggs do hatch, there is a significant relationship between the proportion of fine sediment and the survival of young salmon, or fry. One study showed that a 1% increase in fine sediments results in an average of a 17% reduction in the odds of survival for Pacific salmonids, with slight variations between the different species.

City of Santa Cruz staff conduct an annual fish count in the San Lorenzo River lagoon to gauge the size of the population of steelhead trout in the San Lorenzo River watershed. Photo courtesy and © of the City of Santa Cruz Water Department. — City of Santa Cruz staff conduct an annual fish count in the San Lorenzo River lagoon to gauge the size of the population of steelhead trout in the San Lorenzo River watershed. Photo courtesy of and © the City of Santa Cruz Water Department.

In normal conditions you can grab your fishing pole and fish the San Lorenzo from December 1st, through March 7th, each Saturday, Sunday, Wednesday and on any legal holiday during that time. However, the California Department of Fish and Wildlife banned fishing on the San Lorenzo River during the recent seasons. Because of the severe drought, the State Department felt that closing the rivers was a clear course of action, to protect the already low populations of fish in the river.

Drought Alert

If you receive water from the City of Santa Cruz, it comes from three sources: water that’s been stored in Loch Lomond Reservoir, surface water from the San Lorenzo River, or water outside the San Lorenzo Watershed from north coast stream surface water.

Santa Cruz residents display ‘Doing Our Part to Save Water’ signs on withering lawns. Photo courtesy and © of Soquel Creek Water District. — Santa Cruz residents display ‘Doing Our Part to Save Water’ signs on withering lawns. Photo courtesy of and © of Soquel Creek Water District.

About 50% of it comes from free flowing water in the San Lorenzo River. Since March 2014, Santa Cruz County has been classified as being in a state of “Exceptional Drought”, a title designated by the US Drought Monitor. This is the driest classification possible.

Volunteers measure the transparency of the water at Loch Lomond at the Great American Secchi Dip In in 2015. Transparency is one measure of water quality. Photo courtesy and © of Coastal Watershed Council. — Volunteers measure the transparency of the water at Loch Lomond at the Great American Secchi Dip in 2015. Transparency is one measure of water quality. Photo courtesy of and © Coastal Watershed Council.

Take the Self-Guided Mobile Tour

This piece is part of the San Lorenzo River Tour by the Coastal Watershed Council. Download the free app with many tours of the Santa Cruz area and beyond.