The San Mateo County Flood Control District is a Countywide Special District that was created by State legislation in order to provide a mechanism to finance flood control projects. The legislation requires that a flood control zone be formed over an entire watershed and a proposed funding source be determined before a flood control project is undertaken.  Recent changes in the State Constitution require an election if a flood control zone is to be financed with property assessments or taxes.  There are currently three active flood control zones:

Colma Creek

The Colma Creek Flood Control Zone was created in 1964 to construct flood control facilities in Colma Creek to alleviate flooding in the City of South San Francisco. Originally the project extended from Mission Road in South San Francisco approximately three miles to San Francisco Bay. Several channel improvements were constructed and four bridges replaced before Proposition 13 curtailed the project's funding source (property taxes) in 1978. The plan to improve the Colma Creek Flood Control Channel was re-vitalized in the mid 1990’s by the financing of improvements by the BART Airport Extension Project and a financial contribution from the State Department of Transportation (CALTRANS) for drainage improvements in El Camino Real in Colma and Daly City. The scope of the project was extended upstream from Mission Road to the vicinity of “A” Street in Daly City.

The BART and CalTrans projects were combined with bond financing in the amount of $15.7 million to provide funding for additional flood control facilities within the expanded project limits. Culvert improvements have been made in Old Mission Road and El Camino Real and the South Airport Boulevard Bridge has been replaced.  A collaborative project with the Peninsula Joint Powers Board to replace the Mainline Railroad Bridge over Colma Creek was completed in 2004.  A project that includes channel improvements from Spruce Avenue to San Mateo Avenue and the raising of the San Mateo Avenue Bridge is near completion.  The Colma Creek Flood Control Zone has issued additional bonds to finance and complete the remainder of the planned projects.

Construction between Spruce and San Mateo Avenues on Colma Creek resulted in the filling of half an acre of salt marsh wetlands within the original earthen channel of Colma Creek. Federal and State permits for the current construction require that the District mitigate for these lost wetlands. Therefore the District is constructing 1.5 acres of salt marsh wetlands and 2.0 acres of "native" upland habitat. This project, known as the Colma Creek Flood Control Habitat Mitigation Project, is located along the mouth of Colma Creek where it enters San Francisco Bay, below Utah Avenue. When complete, this habitat is expected to be used by the endangered California Clapper Rail, which has been observed in the area.

San Bruno Creek

The San Bruno Creek Flood Control Zone was established in 1967 to finance the construction of channel and culvert improvements in the lower reach of San Bruno Creek.  The Zone also contributed to the financing of drainage improvements in the City of San Bruno below El Camino Real.  The Zone finances the maintenance of the channels and contracts with the City of San Bruno for pump station maintenance.  The Zone recently removed accumulated silt and vegetation from the open channel area known as “Cupid Row” located between the CalTrain tracks and U.S. 101. Complex Federal and State permits are required to maintain this channel as the area is habitat for the California Red Legged Frog and the San Francisco Garter Snake, both listed as Federal Endangered Species.

San Francisquito Creek

San Francisquito Creek is the boundary between San Mateo and Santa Clara Counties. The San Francisquito Creek Flood Control Zone finances creek improvements in cooperation with the Santa Clara County Water District. The Zone's source of revenue is property taxes, which are limited by Article XIII of the State Constitution. The Creek overtopped its banks in 1998 and flooded portions of the Cities of Palo Alto, East Palo Alto and Menlo Park. The San Francisquito Creek Joint Powers Authority (SFCJPA) was created as a result to develop solutions to the flooding problem and provide for a coordinated approach to planning in the San Francisquito Creek Watershed. The SFCJPA members include the cities of Palo Alto, East Palo Alto, Menlo Park and the Santa Clara Valley Water District and San Mateo County Flood Control District. Stanford University and the San Francisquito Creek Watershed Council are Associate Members. The SFCJPA is currently pursuing a major flood control project with the Army Corps of Engineers to prevent a repetition of the 1998 flood.