US Army Corps of Engineers
Sacramento District Website

confluence of Sacramento and American Rivers

Natomas Basin

Sacramento's Natomas Basin is one of the most at-risk areas in the nation for catastrophic flooding. Improvements to Natomas levees were originally authorized as part of the Corps' American River Common Features project in 1996, intended to improve the system of levees throughout the greater Sacramento area. Since then, the scope and cost of Natomas levee improvements have increased after high water events in 1997 and 2006 showed serious underseepage in the basin. In 2010, a post-authorization change report was completed detailing the Corps' recommended plan for improving Natomas levees. The project to improve the 42-mile ring of levees surrounding the basin was authorized in 2014. The Sacramento Area Flood Control Agency completed the first 18 miles of levee improvements, and the Corps is scheduled to begin construction on the remaining 24 miles in 2018.  

Project Description (By Reach)

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Sacramento's Natomas Basin is one of the most at-risk areas in the nation for catastrophic flooding. Improvements to Natomas levees were originally authorized as part of the Corps' American River Common Features project in 1996, intended to improve the system of levees throughout the greater Sacramento area. Since then, the scope and cost of Natomas levee improvements have increased after high water events in 1997 and 2006 showed serious underseepage in the basin. In 2010, a post-authorization change report was completed detailing the Corps' recommended plan for improving Natomas levees. The project to improve the 42-mile ring of levees surrounding the basin was authorized in 2014. The Sacramento Area Flood Control Agency completed the first 18 miles of levee improvements, and the Corps began construction on the remaining 24 miles in 2018.

 

Sacramento River east levee from the intersection of Garden Highway and Gateway Oaks Dr extending upstream to Farm Rd. The length of this reach is approximately 3.5 miles. The general improvements include widening the existing levee through construction of an adjacent levee, installing seepage cutoff walls (up to 145 feet deep), and constructing landside seepage berms. For more information on Reach A, please visit it's location-specific web page here: https://www.spk.usace.army.mil/Missions/Civil-Works/Natomas-Basin/Reach-A/

Sacramento River east levee from San Juan Road upstream (north) to Elverta Road. The length of this reach is approximately 9.5 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 ft, and flattening the landside levee slope.

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 (NCC). 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 ft, and flattening the landside levee slope.

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.

Pleasant Grove Creek Canal (PGCC) west levee from Howsley Road upstream (south) to Sankey Road. The length of this reach is approximately 3.3 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 65 and 70 feet, and flattening the landside levee slope.

The Natomas East Main Drainage Canal (NEMDC) 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, installation of approximately 2.6 miles of seepage cutoff wall with a depth of approximately 53 feet, and flattening the landside levee slope.

The NEMDC 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, and flattening the landside levee slope.

The NEMDC west levee from the pumping station just upstream of Dry Creek downstream (south) to Northgate Boulevard. The length of this reach is approximately 4.5 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 41 feet, and flattening the landside levee slope.

Construction for Reach I will occur on the American River north levee from Northgate Blvd downstream (west) past Interstate 5 to Gateway Oaks Dr. The length of this reach is approximately 1.8 miles. 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, and flattening the landside levee slope. Construction began in May 2019, and is scheduled to be completed during the 2020 construction season. 

Upcoming Public Engagements

Natomas Reach A Status Update Virtual Public Meeting
Monday, November 16, 2020 from 3-5 p.m.

This meeting will provide a status update on progress towards construction in Natomas's Reach A, which extends along Garden Highway from Gateway Oaks Dr to Farm Rd. Participants will have an opportunity to hear from project leads about ongoing work such as site preparation activities, learn about our schedule moving forward, and ask questions to the team. 

For an orientation ahead of time, click here to watch a short (2 min) YouTube video of the project: 
ttps://www.youtube.com/watch?v=M59mZ70ze5M

View: Presentation Slides (PDF)

To Join our Webinar: https://usace1.webex.com/usace1/j.php?MTID=m8d624937e8f86320a5f1624fd2f41d4a

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project map

 Project map by construction reach (Click to enlarge)

Recent Documents

Reach D, Pumping Plant 4, Draft Supplemental EA - September 2020
This document has a 30-day public review and comment period, which closes on November 4, 2020. You can submit your comments electronically to spk-pao@usace.army.mil. For any questions, please contact our Public Affairs Office at 916-557-5100. 
Notice of Availability
Draft Report
Supplemental Plates
Draft FONSI

 

Reach B, Interstate 5 Window Draft Supplemental EA - July 2020
Draft Report
Draft FONSI

Natomas Levees Overview

Button to Natomas Basin Levee Improvements Reach A Information

Contact Information

For more information on Natomas Basin levee improvements, 
please contact us at the following:

Phone: 
916-557-5100

Email:
spk-pao@usace.army.mil

Mailing Address:
U.S. Army Corps of Engineers,  Sacramento District
Natomas Basin project
1325 J Street, Room 1513
Sacramento, CA 95814