The Sutter Butte Flood Control Agency is repairing 44 miles of levees from Thermalito Afterbay south to the Sutter Bypass. The goal of the project is to reduce flood risk and eventually remove more than 34,000 properties from FEMA Special Flood Hazard Areas. Levee repairs are being completed in two separate projects (see below).
The repairs are needed because levees along the west bank of the Feather River suffer from potential underseepage and through-seepage. Similar problems caused major levee failures in Yuba City in 1955 and Yuba County in 1986 and 1997.
In general, the Feather River levees will be made stronger by building deep cutoff walls (also known as slurry walls) and seepage berms. These levee improvements block or slow the flow of water through and underneath the levees. Not all 44 miles of levees will need each of these improvements. More than 80 percent of the repairs will involve the construction of slurry walls, some as deep as 130 feet. In a few select areas, seepage berms were constructed on the land side of the levee.
The levee improvement program is expected to:
Levee repairs will be completed in two separate phases:
The most recent cost estimate – $378 million – reflects the combined costs of the Feather River West Levee Project I, which is nearly completed, and Project II work. This estimate will continue to be refined as the projects move toward completion. To date, the State is expected to pay as much as 78 percent of the costs for Project I. Property assessment revenues (approved by property owners in June 2010) will be used to pay the remaining share. As of January 2019, the State has committed $226.8 million toward the design and construction of Project I. In addition, the State committed up to $4.2 million for emergency measures to address flooding in February 2017. SBFCA recently completed Laurel Avenue Repair Project at a cost of $11.15 million with the State funding $9.5 million of these costs. In addition, SBFCA has secured State and Federal Funding for the Sutter Basin Levee Improvement Project (Feather River West Levee between Cypress and Tudor). The Total Project is expected to cost $77 million with the Federal Government funding approximately $50 million and the State funding approximately $18.9 million. Assessment revenues will fund the remainder.
On April 20, 2016, SBFCA released the Draft Supplemental Impact Report (Draft SEIR) for the Feather River West Levee Project for a 45-day public review period. The SEIR analyzed modifications to the original project. The public review period ended on June 3, 2016.
Five comment letters were received during the public comment period. The Final Supplemental Environmental Impact Report (Final SEIR) contains these comment letters, SBFCA’s responses to the comment letters, and the changes (shown in underline and strikeout) that have been made to the text since the Draft SEIR publication. Click here to view/download the report.
|Adequate Progress Report||2MB|
|Engineer’s Response to IPE Report||349kB|
|FRWLP Final Supplemental Environmental Impact Report||43MB|
|Report from Independent Panel of Experts (IPE)||2MB|
|200-Year Post Floodplain Mapping||12MB|
|2nd Street Encroachments||26MB|
|Additional Explorations Phase C||4MB|
|Additional Explorations Phase D||4MB|
|Alt Cost Analysis||24MB|
|Appendix D Geotech Analysis for Pre-Design Formulation Report||130MB|
|Approach for Addressing Existing Levee Encroachments||4MB|
|Approach to Improve Geometry||1MB|
|Design Criteria & Technical Approach||8MB|
|Design WS Profiles||22MB|
|Design WS Profiles Addendum 1||16MB|
|Design WS Profiles Addendum 2||4MB|
|DMM Cutoff Wall Reach 13||17MB|
|Encroachment & Penetration TM||619kB|
|End Around Effects Paper||505kB|
|Evaluation of End Around Effects||9MB|
|Flood Safety Plan||258kB|
|Frequently Loaded Levee Analysis||2MB|
|LS Slope Stability TM||91kB|
|Magnus Submittal 241||5MB|
|Magnus Submittal 40||1MB|
|Magnus Submittal 56||2MB|
|Magnus Submittal 67||1MB|
|Magnus Submittal 80||5MB|
|O&M Manual Unit 144||66MB|
|O&M Manual Unit 148||62MB|
|O&M Manual Unit 152||22MB|
|Recommendations for Reach 13||10MB|
|Relief Well Design for UPRR Relief||11MB|
|Review of Transition in Cuttoff Wall Depth Reach 13||2MB|
|Sutter-Butte Main Canal Investigation||6MB|
|Update to Relief Well Design Reach 17||17MB|
|UPRR Closure Structure O&M Overview||34kB|
|UPRR Closure Structure Plans||7MB|
|Wind Setup & Wave Run Up Analysis||7MB|
|Wind Setup & Wind Run Up Analysis||7MB|
|YCRW Gap TM||5MB|