Delta Conveyance and Flood Protection

Farmland and waterways in the Sacramento-San Joaquin Delta. DWR/2009

The Delta is a unique area of California, located at the confluence of the Sacramento and San Joaquin rivers, where the elevation of the land surface is as much as 25 feet below sea level.  This area is protected from daily flooding by an extensive system of privately owned levees (730 miles) and levees that are part of the State Plan of Flood Control (380 miles).

We work with local governments to maintain and improve the levees that protect river inflow from becoming brackish with seawater intrusion, and assure conveyance of fresh water across the Delta. The Delta is the source of irrigation, municipal, and industrial water supplies for two-thirds of California’s population. 

Delta levees also protect populations and infrastructure of statewide importance from flooding.  The programs we oversee provide funding to levee maintaining agencies for their use to protect and improve these critical levees through the Delta Levees Maintenance Subventions Program and the Delta Special Flood Control Projects Program.  Additional initiatives we have undertaken are the Delta Knowledge Improvement Project and the Delta Land Use Project, which includes the North Delta Project and the West Delta Program.


We maintain extensive GIS datasets involving the Delta islands, the levees,  bathymetry of Delta channels, Delta hydrology, subsidence, carbon flux, methyl mercury, and tides. Contact us if you're interested in any of these datasets.

Reports & Publications

The Delta Risk Management Strategy is a comprehensive study of the Delta and the condition of its levee system in 2006.  Assumptions were made regarding flood potential for each Delta island based on conditions existing at the time. 



The Delta Levees Program offers grant funding to levee maintaining agencies inside the legal Delta (CWC 12220).  Eligible participants are local agencies responsible for maintaining non-project levees in the Delta and project levees in the primary zone of the Delta.  Grant programs include the Delta Levees Maintenance Subventions Program and the Delta Special Flood Control Projects Program.


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