About the River

Why it matters

San Lorenzo River

You drink it.

Approximately 54% of the drinking water for the City of Santa Cruz comes directly from surface water of the San Lorenzo River. Additionally, Loch Lomond reservoir is located on a tributary to the San Lorenzo River, and if you include this reservoir then 66% of City of Santa Cruz drinking water comes from the San Lorenzo River watershed. 100,000 people rely on this drinking water source and if you’re one of the thousands of people who visit Santa Cruz each year, you drink this water too!

Santa Cruz Beach Boardwalk and San Lorenzo River

It’s home.

Santa Cruz exists where it does today because of the San Lorenzo River. Native peoples relied on this freshwater resource and so did the Spanish settlers when they arrived in the late 18th century. Downtown Santa Cruz was built along the lower San Lorenzo River and it was a huge part of daily life for decades. However, following the devastating Christmas Flood of 1955 levees were built that walled off the San Lorenzo River to downtown Santa Cruz. Today, we are re-embracing our urban riverfront. A city park lies on the tops of the levees and is known as the Santa Cruz Riverwalk.

Parade on the San Lorenzo River levee

It’s for all of us.

The San Lorenzo River can be a driver of economic activity, thriving habitat for birds, bugs and fish, a destination for tourism and recreation and a beautiful natural place the community can feel proud of and safe near. The lower river is home to approximately 238 species of birds. It’s home to fish species like the endangered tidewater goby, endangered Coho salmon and threatened steelhead trout. And it’s a city park, a greenbelt for alternative transportation and a place for people to reconnect to nature right in the heart of downtown Santa Cruz. Just like the urban riverfronts you hear about across the globe, we too can have a safe, clean and fun San Lorenzo River that connects our community to nature.

River Facts

  • The San Lorenzo River is 29.3 miles long.
  • The San Lorenzo River watershed is 136 square miles and includes the cities of Santa Cruz, Boulder Creek, Ben Lomond, Felton, and Scotts Valley.
  • Nine principle tributaries flow into the San Lorenzo River
  • The San Lorenzo River was once used to transport logs from the Santa Cruz Mountains
  • There are 11 dams in the San Lorenzo River Watershed
  • The headwaters of the San Lorenzo River start in Castle Rock State Park at an elevation of 2,500 feet
  • The San Lorenzo River was once one of the most popular steelhead and coho salmon rivers on the Central California Coast
  • The San Lorenzo River and Valley were named in 1769 by the Portola expedition


Take a Park Ranger With You

You can learn more about the history, ecology and stories of the San Lorenzo River online or on your mobile device using the Mobile Ranger app. Learn about the management of the San Lorenzo River lagoon, the raucous river festivals of yesteryear and balancing the needs for public safety, habitat management and flood control.

Take the tour today!