Stormwater runoff from the city is a major contributor of pollutants to the San Lorenzo River and Monterrey Bay. Additionally, parts of the downtown area are located within the 100-year floodplain. In partnership with the U.S. Army Corps of Engineers and State of California, the San Lorenzo River Flood Control Project was created to control stormwater and reduce flooding.
The U. S. Army Corps of Engineers and the City of Santa Cruz agreed to raise the height of the San Lorenzo River Levees from one to five feet and restore riparian habitat along the levees. A second part of this project was the replacement or repair of the Riverside Avenue Bridge, the Water Street Bridge, the Soquel Avenue Bridge, and the retrofit of the Broadway/Laurel Bridge. The third part of this project was to extend Laurel Street and stabilize the banks of Third Street. A natural rock wall was formed along this section to harden and prevent the collapse of these streets into the river. Vegetation was also planted along the toe of the wall adjacent to the river to provide shade for fish and other wildlife.
Implementation & Funding
The San Lorenzo Flood Control Project’s $66 million budget was shared between Federal, State and City Governments. The City created the Stormwater Management Utility to establish and collect utility fees, allowing the city to contribute an estimated $4.4 million to help pay for its share of costs for flood control projects and stormwater pollution prevention. The U. S. Army Corps of Engineers aided in raising the levees of the San Lorenzo River. Congress approved this levee raising in phases, and eventually the State joined forces with the City and Federal Government. Bridge construction was funded both federally and through city stormwater fees and taxes. Bank stabilization was a joint effort with the use of City, State and Federal funds.
A flood in December 1955 caused $40 million in damage, which is equivalent to $340 million in damage today. The U. S. Army Corps of Engineers estimates that a 100-year flood in Santa Cruz would now only cause $86 million in damage; therefore, these flood control measures are potentially saving the city tens of millions of dollars in losses from future floods. In 2002, while the project was not yet complete, FEMA recognized that the levees were already providing increased flood protection and granted an interim A99 flood zone designation to most parcels in the 100-year floodplain to enable the levee project to be factored into the community’s insurance rating. This designation allows flood insurance premiums to be reduced by 40%.