This area faces significant risks to public health, safety, and property due to flooding, as evidenced by major flood events in 1955, 1958, and 1997. The project entails 23 miles of levee improvements, including cutoff walls, deep soil mixing for seismic stability, a new levee, levee geometry enhancements, and erosion protection. Additionally, two closure structures will be constructed at Fourteenmile Slough and Smith Canal. Non-structural measures, such as comprehensive flood warning, emergency evacuation planning, and floodplain management, are also included.
The project is set to benefit approximately 162,000 residents by improving federal and local levees for flood risk management. It is expected to reduce flooding risk for about 122,000 people, over 80,000 structures, and properties valued at $28.7 billion. Moreover, the project promises an estimated 83 percent reduction in expected annual property damage and enhanced security for 486 critical infrastructure sites, including 23 essential for life safety. The total annual benefits of the project are estimated at $345,024,000, with net annual benefits of $295,730,000.
As of 2020, the project's cost was estimated at approximately $1.3 billion. It will enable the local community to continue meeting the Federal Emergency Management Agency's certification requirements and, partially, the State of California's criteria for Flood Risk Management project funding. This could lead to a reduction in National Flood Insurance Program costs for the community. The construction of the project is anticipated to start in 2024 and complete by 2037.