Natomas Basin Reach A - Levee Improvement (Sacramento, California, USA)

  • 10/10/2023

The U.S. Army Corps of Engineers (USACE), in partnership with the California Central Valley Flood Protection Board (CVFPB), California Department of Water Resources (DWR), and the Sacramento Area Flood Control Agency (SAFCA), awarded a project to improve the levee infrastructure along the Garden Highway levee from Farm Rd to Gateway Oaks Drive, spanning 3.5 miles (3,000 m). This endeavor is an integral component of the American River Watershed Common Features - Natomas Basin project, which received congressional authorization in 2014. Extensive geotechnical engineering analyses have shown vulnerabilities to seepage and significant landside slope stability issues, along with long-term operational and maintenance concerns within the levee system. The Natomas Reach A commenced in 2022, the levee improvements will comprehensively address these identified deficiencies. This will be achieved through the construction of an adjacent levee to widen the existing structure, installation of seepage cut-off walls, reaching depths of up to 145 feet (44.2 m), and the creation of landside seepage berms.


Scope of Work:

The primary scope of work involves the installation of a soil mixed cut-off wall, featuring a minimum width of 27 inches (686 mm) and descending to a maximum depth of 145 feet (44.2 m). To achieve this, BAUER Foundation Corp. employs cutting-edge equipment, including three BAUER BG 45 drilling rigs and one BG 55 rig. Additionally, the project utilizes four Cutter-Soil Mixing attachment BCM 10 units equipped to reach depths exceeding 44.2 meters, with steering assist systems ensuring the 0.5% verticality is maintained.


Schedule of Work:

Project activities are limited to the period from April 15th to November 1st, aligning with the seasonal constraints in levee operations. The project timeline aims for completion by November 2026.