San Lorenzo River: Whats in a Watershed: Part II

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

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.

Read the rest of the story and find out who’s tap water comes from the San Lorenzo River here at MobileRanger.com.

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Julia Gaudinski


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