Reclamation District 17 Levee Seepage Repair

Reclamation District No. 17 encompasses approximately 16,108 acres at the eastern edge of the Sacramento-San Joaquin Delta. The 19 miles of levees in the district originally constructed to provide protection from floodwaters of streams, creeks, rivers and bypasses that empty into the Sacramento-San Joaquin Delta, and from extreme high tides.
 
The Reclamation District 17 levee infrastructure protecting the Mossdale Tract Area failed to meet state requirements for 200-year flood protection. Properties in this area faced two types of risk: physical damage to properties, and economic impacts associated with not meeting state requirements.  The San Joaquin Area Flood Control Agency SJAFCA needed implement fix‐in‐place levee improvements to reduce flood risk and meet state requirements. 

To complete the project on time, Forgen managed up to 4 simultaneous sections of the levee system. By dividing the levee into multiple sections and working on them concurrently, we significantly reduced the project duration. This approach allowed for efficient allocation of resources and minimized downtime, ensuring that each section progressed at a consistent pace without waiting for the completion of others.

Our team completed 18,300 linear feet (3.5 miles) of flood protection across five separate locations. This geotechnical and heavy civil project involved building levee embankments, installing 1,110,000 square feet of soil-bentonite slurry walls, constructing 232,000 square feet of Deep Soil Mixing (DSM) walls, and installing seepage berms. The scope of work for the project included placing 268,346 cubic yards of levee material, degrading 80,000 CY of existing levee, and completing 250,000 CY of earthwork.

Our team was also responsible for the associated clearing and grubbing of the project site, utility relocation, demolition, rock slope protection, staging areas, and utility corridors. We coordinated all efforts with local farmers and the City of Lathrop to maintain continuous service throughout the project, ensuring minimal disruption to essential services.

As part of the utility relocation, we managed the bypass and installation of steel intake and outfall piping ranging from 18 to 30 inches in diameter. This piping is crucial for levees, as it allows for the controlled management of water levels by directing water in and out of the protected areas, ensuring stability and preventing erosion or flooding. In total we installed 450 linear feet (LF) of pipes.

Forgen executed this project while maintaining strict adherence to State and Federal environmental regulations in this ecologically sensitive area.

This collaborative effort not only met the state’s 200-year flood protection requirements but also mitigated risks of physical and economic damage to properties within the Mossdale Tract Area. The project stands as a testament to our commitment to safety, resilience, and operational excellence in flood control infrastructure.