Lower San Joaquin River Project



The San Joaquin River Basin, Lower San Joaquin River, CA project will provide flood risk management for the City of Stockton, CA.   There is significant risk to public health, safety, and property in the project area associated with flooding, with major flood events having occurred in 1955, 1958, and 1997. The project will include 23 miles of levee improvements and two closure structures, one at Fourteenmile Slough and the other at Smith Canal. The levee improvements include cutoff walls, deep soil mixing (seismic), a new levee, levee geometry improvements and erosion protection. Non-structural measures include nonstructural features, such as Comprehensive Flood Warning Emergency Evacuation Planning and Floodplain Management. The project is expected to provide benefits to 162,000 residents by improving Federal and local levees that provide flood risk management. The project area levee system will provide flood risk management benefits to more than 71,000 acres of mixed-use land with a current population estimated at 264,000 residents and an estimated $21 billion in property. The project will also offer the area an estimated 83 percent reduction in expected annual property damage, while enhancing security at 486 critical infrastructure sites – 23 of which are essential to life-safety.  Total annual benefits of the project estimated at $345,024,000 and net annual benefits is $295,730,000. As of 2022, the expected cost of the project was estimated at approximately $2.03 billion.  The project would allow the local community to continue to meet both Federal Emergency Management Agency certification requirements and at least a portion of the State of California’s criteria for funding of Flood Risk Management projects, allowing for potential reduction in National Flood Insurance Program costs to the community. Project construction is currently anticipated to start in 2024 with completion in 2037.

Maps & Phases

View Larger Interactive Map     Study Area Map (2017)

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 Phase A – Shima Tract

Type of Work: Levee fix in place with the addition of a cut-off wall, as well as the addition of waterside erosion protection.

Location: North Stockton west of Interstate 5 and north of Schooner Drive to Sturgeon Road.

Length: Approx. 8,400 ft.

Dates: Scheduled construction start 2028.

Other Info: Phase A is the second planned reach to be improved under the Lower San Joaquin River Project. Upon completion, the levee will be Federally operated. The waterside of levee is farmland.

 Phase B – Fourteenmile Slough

Type of Work: Levee fix in place and new levees, with the addition of a cutoff wall, height improvements, geometry improvements, and a closure structure.

Location: North Stockton along the Fourteenmile Slough.

Length: Approx. 10,400 ft.

Dates: Scheduled construction start 2032.

 Phase C - Tenmile Slough, Calaveras River

Type of Work: Levee fix in place with the addition of a cutoff wall, seismic fixes, and levee reshaping and geometry improvements.

Location: Right bank of the Calaveras River, south of March Lane to N. El Dorado Street (Phase C-2), including a small portion North of the Calaveras on the San Joaquin River (Phase C-1, reaches TS10L and TS20L).

Length: Approx. 28,600 ft.

Dates: Scheduled construction start 2032.

 Phase D – Calaveras River, San Joaquin River

Type of Work: Levee fix in place with the addition of a cutoff wall, geometry improvements, height improvements and retention walls.

Location: Left bank of the Calaveras River, north of Monte Diablo Avenue to N. El Dorado Street, including a small portion South of the Calaveras on the San Joaquin River near Smith Canal.

Length: Approx. 27,500 ft.

Dates: Scheduled construction start 2035.

 Phase E – San Joaquin River, French Camp Slough, Duck Creek

Type of Work: Levee fix in place with the addition of a cutoff wall, construction of new levees, levee reshaping and geometry improvements.

Location: South of the Port of Stockton along the San Joaquin River, French Camp Slough, and Walker Slough, adjacent to Van Buskirk Park to S. El Dorado Street.

Length: Approx. 30,400 ft.

Dates: Scheduled construction start 2033.

 Phase F – Mosher Creek

Type of Work: Levee fix in place with the addition of a cutoff wall and height improvements.

Location: North Stockton from Mosher Slough east to Thornton Road.

Length: Approx. 10,700 ft.

Dates: Scheduled construction start 2032.

 TS30L – Tenmile Slough

Type of Work: Levee fix in place with the addition of a cut-off wall, geometry reshaping, and waterside erosion protection.

Location: Stockton, at the western border of the Brookside housing development, and north of March Lane along the Tenmile Slough.

Length: Approx. 5,900 ft.

Dates: Scheduled construction start 2024.

Other Info: Upon completion, the levee will be Federally operated. The waterside of levee is farmland.

 Smith Canal

Construction on the Smith Canal Gate Project began in 2020, as part of the Lower San Joaquin River Project. Constructed by SJAFCA, partnered with Reclamation Districts 1614 and 828, the project consists of a floodwall along the San Joaquin River from Dad’s Point to the eastern boundary of the Stockton Golf & Country Club, tying into the existing levee. The floodwall features a gate for tidal exchange and boat access to Smith Canal, and will remain open unless there is a flood event. More information can be found on the SJAFCA Smith Canal webpage.

 

Links

Central Valley Flood Protection Board

San Joaquin Area Flood Control Agency

Contact Information

For more information
on the Lower San Joaquin River project, 
please contact us at the following:

Phone:
916-557-5100

E-mail:
spk-pao@usace.army.mil

Mailing Address:
U.S. Army Corps of Engineers
Sacramento District
1325 J Street, Room 1640
Sacramento, CA 95814