Reach A: Reach A consists of the Sacramento River East Levee between Gateway Oaks Drive to Farm Road. The length of this reach is approximately 3.5 miles. The upstream 2.3 Miles of the project will widen the existing levee a minimum of 15 feet to allow construction of an underground cutoff wall with a maximum depth of approximately 142 feet.  This widening will also flatten the landside levee slope. Beneath Interstate 80, a seepage berm will be constructed on the land side of the levee. The remaining 1.2 miles consists of levee widening that includes a drained seepage berm. The pumping stations at City Sump 160 and the two Pumping Plants at the RD1000 office will also be improved with this project.  The Post-Authorization Change Report and Interim Reevaluation Report American River Watershed evaluated the use of a seepage berm in certain areas of this reach. The contract was awarded on Sep. 23, 2021 and construction began in Aug. 2022. For more information on Reach A, please visit the Reach A webpage.

Sacramento River east levee from Farm Road upstream (north) to Elverta Road. The length of this reach is approximately 9.7 miles. The general improvements include widening the existing levee by construction of an adjacent levee, installation of approximately 4.3 miles of a seepage cutoff wall that ranges in depth between approximately 40 and 115 feet, and installation of approximately 5.6 miles of seepage berms that range in width from approximately 80 to 300 feet, and flattening the landside levee slope. A portion of the Reach B features were constructed by the Non-Federal Sponsors upstream of approximately Powerline Rd, apart from several “windows” within the alignment that were left for the USACE to construct. The USACE Reach B contract spans along Garden Hwy from just downstream of Powerline Road, south to Farm Road and consists of 2.3 miles of adjacent levee construction, an irrigation pipeline relocation, improvements to Pumping Plant #3, and seepage berm construction. The contract was awarded on Nov. 14, 2019.

Reach B I-5 Window: The contract was awarded on May 7, 2021. Construction work consisted of seepage berm extension and general earthwork underneath the I-5 overpass and the junction of North Bayou Way at the Elkhorn Boating Facility. Construction was substantially completed in 2023.

Reach B PP#5: This is a Flood Damage Reduction project located just north of downtown Sacramento located in Reach B. Upgrading of interior drainage pumping plant and relocation of discharge pipes crossing levee. The design will be complete in 2026 and construction is scheduled to begin in 2027.

Reach B Riverside Pumping Plant Relocation: On behalf of the Non-Federal Sponsors, the Natomas Central Mutual Water Company (NCMWC) will be replacing the Riverside Pumping Plant and relocating the discharge pipes up and over the levee and above the 200-year flood elevation. This will occur in two phases with the first being the pumping plant replacement which was awarded in Summer 2022 with construction 100% complete. The second phase is the relocation of the discharge pipes which is scheduled to begin late 2027.

Reach B Elkhorn Pumping Plant Relocation: On behalf of the NFS, the NCMWC will be replacing the Elkhorn Pumping Plant and relocating the discharge pipes up and over the levee and above the 200-year flood elevation. This will occur in two phases with the first being the pumping plant replacement which was awarded in April 2024. Construction began in summer 2024 and lasted two seasons. The second phase is the relocation of the discharge pipes, which is scheduled to begin late 2027.

Sacramento River east levee from Elverta Road upstream (north) to Sankey Road at the west end of the south levee of the Natomas Cross Canal. The length of this reach is approximately 5 miles. The general improvements include widening the existing levee by construction of an adjacent levee, installation of approximately 4.6 miles of seepage cutoff wall that ranges in depth between approximately 19 and 65 feet, and installation of approximately 2.7 miles of seepage berms that range in width from between approximately 100 to 500 feet, and flattening the landside levee slope.

Reach C Pritchard Lake Pumping Plant Relocation: On behalf of the Non Federal Sponsors, the Natomas Central Mutual Water Company replaced the Pritchard Lake Pumping Plant in 2015, except for the installation of one of the three new pumps. The installation of the last pump and the relocation of the discharge pipes up and over the levee and above the 200-year flood elevation will occur during the second phase of construction and is scheduled for Fall 2027. 

Natomas Cross Canal south levee from Sankey Road upstream (northeast) to Howsley Road at the PGCC. The length of this reach is approximately 5.5 miles. The general improvements include widening the existing levee by fix in-place construction, and installation of a seepage cutoff wall that ranges in depth between approximately 60 and 75 feet, and flattening the landside levee slope. The construction contract was awarded on May 10, 2018. Construction began Aug. 13, 2018, with physical construction completion on Nov. 22, 2021.

Reach D, Pumping Plant #4: Flood Damage Reduction project in the northwest corner of Natomas Basin adjacent to the Natomas Cross Canal. Work involves demolition and rebuild of the pumping plant including elevation of three stormwater pipes 10 feet to design water surface elevation, and a new electrical station and pumping plant. Work includes the demolition and replacement of Pumping Plant 4 including elevation of three stormwater pipes 10 feet to design water surface elevation, and a new electrical station and pumping plant. The construction contract was awarded on Feb. 11, 2021, and construction began on May 18, 2021, with physical construction completion anticipated for Fall of 2027.

Reach D, HWY99:  Reach D levee improvements were completed by the Non Federal Sponsors in 2010 with the exception of an approximately 690-foot section (window) of the levee where the Highway 99 bridge crosses over the top of levee. The Hwy 99 project includes a 750-foot-long cutoff wall which overlaps and closes the gap between the cutoff walls constructed by the NFS. The construction contract was awarded January 17, 2024, and construction began in June 2024, with physical construction completed in the Fall of 2025.

Pleasant Grove Creek Canal west levee from Howsley Road upstream (south) to Sankey Road. The length of this reach is approximately 3.4 miles. The general improvements include widening the existing levee by fix in-place construction, installing an adjacent levee, installation of a seepage cutoff wall that ranges in depth between approximately 38 and 50 feet, flattening the landside levee slope and replacement of (5) underdrain culverts and gatewells. The contract was awarded on April 10, 2023, and construction began June 2023. The construction contract was awarded on April 10, 2023 and construction began in June of 2023, with physical construction completion anticipated for Fall of 2026.

The Natomas East Main Drainage Canal west levee from Sankey Road downstream (south) to Elverta Road.  The length of this reach is approximately 4.7 miles. The general improvements include widening the existing levee by fix in-place construction, levee widening, flattening the landside levee slope and installation of a patrol road. The design is 100% complete and construction is planned for the 2028/2030 construction seasons.

The Natomas East Main Drainage Canal west levee from Elverta Road downstream (south) to the drainage pumping station just upstream of Dry Creek.  The length of the reach is approximately 3.6 miles. The general improvements include improving the levee by fix in-place construction, and installation of a seepage cutoff wall with a depth of approximately 40 feet near Pump Station No. 6, levee widening, flattening the landside levee slope and installation of a patrol road. The design is 100% complete and construction is planned for the 2028/2030 construction seasons.

The Natomas East Main Drainage Canal west levee requires cutoff wall improvements from the pumping station just upstream of Dry Creek downstream (south) to Arden-Garden Connector Bridge. The length of this reach is approximately 4.0 miles. The general improvements include improving the existing levee by fix in-place construction, and installation of a seepage cutoff wall with a depth of approximately 30-70 feet and flattening the landside levee slope. There are two pumping stations which will require the discharge pipes to be raised and installation of a landside maintenance road.  The design was done by AE firm Wood Rodgers. The construction contract was awarded on Jan. 23, 2019, and construction began May 2019, with physical construction completed May 2024.

The Reach I project was planned to be constructed during two contracts of work.

Contract 1 - The Natomas Basin Reach I Contract is located on the reach of Natomas levee adjacent to the American River in Sacramento, CA. Reach I Contract 1 includes installation of approximately two miles of cement-bentonite cutoff walls between Gateway Oaks Boulevard and Northgate Boulevard, mostly centered on Garden Highway. The cutoff walls will have an average depth of 45 feet. Excavation spoils will be hauled to a site identified herein to be spread and compacted. A landside drainage blanket will be installed on the levee slope underneath Interstate 5. Relocation and/or removal of waterlines, sanitary force mains, and other utilities are included in the contract.  Multiple lane closures, road closures, and bicycle trail closures are also included. The construction contract was awarded on July 30, 2018, and construction began Oct 2018, with physical construction completed on Nov. 4, 2020. 

Contract 2 - The American River north levee from Northgate Boulevard downstream (west) to Interstate Highway 5. The length of this reach is approximately 1.8 miles. The general improvements include improving the levee by fix in-place construction, and installation of a seepage cutoff wall with a depth of approximately 37 feet, flattening the landside levee slope and installation of a patrol road. The Reach I project was planned to be constructed during two phases of work (contracts). Reach I Contract 1 included installation of the cutoff wall and was completed by USACE in Nov. 4, 2020. Reach I Contract 2 is in the final design phase and includes the landside improvements. Construction for Reach I Contract 2 is planned for the 2027 construction season.

Overall Natomas Mitigation includes creation of Woodland Mitigation in various sites including Novak and the Woodland Corridor, 80 acres of Giant Garter Snake Habitat and improvements to the West Drain to enhance connectivity between Giant Garter Snake habitats. The Natomas Basin is a unique ecological system separated from other systems by a circular levee system. A Biological Assessment was performed which accurately described the mitigation measures. As a result of this coordination the BO’s received for the previous four phases have obtained mitigation measures similar to what was proposed in the BA. Project mitigation needs have been coordinated with U.S. Fish and Wildlife Service, National Marine Fisheries Service, and the California Department of Fish and Game.