2020-06811. Notice of Intent To Prepare a Draft Supplemental Joint Environmental Impact Statement/Environmental Impact Report for the 2007 Folsom Dam Safety and Flood Damage Reduction Environmental Impact Statement/Environmental Impact Report

AGENCY:

Department of the Army, U.S. Army Corps of Engineers; DOD.

ACTION:

Notice of intent.

SUMMARY:

The U.S. Army Corps of Engineers, Sacramento District (USACE) intends to prepare a Draft Supplemental Joint Environmental Impact Statement/Environmental Impact Report (EIS/EIR) for the 2007 Folsom Dam Safety and Flood Damage Reduction EIS/EIR (2007 EIS/EIR) and the 2017 Folsom Dam Raise Project Final Supplemental Environmental Impact Statement/Environmental Impact Report (2017 SEIS/EIR). USACE will serve as lead National Environmental Policy Act (NEPA) agency and the Central Valley Flood Protection Board (CVFPB) will serve as lead agency for compliance with the California Environmental Quality Act (CEQA). The Folsom Dam Safety and Flood Damage Reduction Project (hereafter referred to as the Project) was originally authorized in the 2004 Energy and Water Development Appropriations Act (EWDAA) and was later reauthorized in the 2007 Water Resources Development Act (WRDA). The Project is authorized for four components:

(1) Emergency spillway gate modifications.

(2) Raising the right and left wings of the main dam, Mormon Island Auxiliary Dam (MIAD), and the reservoir Dikes 1 through 8 by 3.5 feet.

(3) Temperature control shutter automation and reconfiguration.

(4) Downstream ecosystem restoration of Bushy Lake and Woodlake.

This Draft Supplemental Joint EIS/EIR will address components of the authorized Project not previously addressed in the 2017 Folsom Dam Raise Project Final SEIS/EIR. Specifically, these components include construction of a new Dike 3, use of onsite borrow and multiple disposal locations including MIAD West and South and potential off-site locations, use of a rock crushing plant at MIAD East, use of on-site concrete batch plants for the Right Wing Dam and Left Wing Dam, and a detailed comprehensive plan for mitigation and restoration upon completion of construction. The flood risk management components of the Project will enhance the utilization of the existing surcharge flood storage space (temporary water storage space utilized during low-frequency flood events), and will increase the surcharge flood storage capacity of the reservoir.

DATES:

Written comments regarding the scope of the environmental analysis should be received by May 8, 2020.

ADDRESSES:

Written comments and suggestions concerning this Project and requests to be included on the Project mailing list may be submitted to Bert Skillen, U.S. Army Corps of Engineers, Sacramento District, Attn: Environmental Analysis Section (CESPK-PDR-A), 1325 J Street, Sacramento, CA 95814.

FOR FURTHER INFORMATION CONTACT:

Bert Skillen via telephone at [phone], email at [e-mail], or mail at (see ADDRESSES). Study information will also be posted periodically on the internet at: https://www.spk.usace.army.mil/​Missions/​Civil-Works/​Folsom-Dam-Raise/​.

SUPPLEMENTARY INFORMATION:

1. Proposed Action. The Corps is preparing a Draft Supplemental Joint EIS/EIR to analyze a single Project alternative with multiple measures to improve flood risk management along the American River. The no-action alternative would be to follow the actions outlined in the 2017 Folsom Dam Raise Final SEIS/EIR. The measures of the single alternative proposed include constructing a new Dike 3 approximately 80 feet closer to the lake than the existing Dike 3, onsite borrow and disposal at MIAD West and South, a rock crushing plant at MIAD East, concrete batch plants for the Right Wing Dam and Left Wing Dam, and a comprehensive plan for mitigation and restoration upon completion of construction. The Project would improve flood risk management while also addressing certain dam safety issues associated with passing the probable maximum flood.

2. Measures. The following measures may be considered as part of the alternatives analysis:

Dike 3 Raise: Constructing a new Dike 3 approximately 80 feet closer to Folsom Lake would lower risk. This measure also maintains flood protection by leaving the existing Dike 3 in place while the new Dike 3 is constructed.

Borrow and Disposal: Some of the material for raising Dikes 1 through 6 and MIAD would come from onsite sources at MIAD West and South and other possible locations. Disposal materials from construction would be deposited onsite at MIAD West and South and other possible locations once borrow is complete. The remainder of the borrow materials would come from, and any additional disposal would be hauled to, commercial sites up to 30 miles away.

Rock Crushing Plant at MIAD East: Placing a rock crushing plant at MIAD East to utilize the existing riprap stockpile will allow for the crushed material to be used for various portions of the 3.5 foot raise of Dikes 1 through 6, the Left and Right Wing Dams, and MIAD.

Onsite Concrete Batch Plants for the Right and Left Wing Dam Raises: Producing concrete onsite will reduced costs and other impacts for hauling the large quantities of concrete. This will also aid constructability given the limited on-site access for equipment and materials.

Plan for Mitigation and Restoration: Including a comprehensive plan for mitigation and restoration of sites affected by the Folsom Dam Raise in this SEIS/EIR will alleviate the need for an additional SEIS/EIR in the future. Although some information concerning mitigation and restoration was included in the 2017 Folsom Dam Raise Final SEIS/EIR, that document cited the need for additional planning once the design of the Folsom Dam Raise was closer to completion.

3. Scoping Process.

a. A public scoping meeting will be held in the form of a teleconference and/or webinar to present an overview of the Folsom Dam Raise, the proposed alternative, and the EIS/EIR process, and to afford all interested parties an opportunity to comment on the scope of analysis and potential alternatives. The public scoping webinar will be held in April, 2020. Exact date, time, registration details, additional information, and any schedule changes will be announced online at: https://www.spk.usace.army.mil/​Missions/​Civil-Works/​Folsom-Dam-Raise/​.

b. Potentially significant issues to be analyzed in depth in the Draft Supplemental Joint EIS/EIR will include: impacts to water quality, air quality, climate change, special status species, terrestrial vegetation and wildlife, recreation, traffic and circulation, noise, aesthetic and visual resources, and cultural resources. The document will also evaluate cumulative effects.

c. USACE will consult with the U.S. Fish and Wildlife Service to comply with the Endangered Species Act and the Fish and Wildlife Coordination Act. USACE will also consult with the State Historic Preservation Officer and Native American Tribes to comply with the National Historic Preservation Act.

d. A 45-day public review period will be provided for individuals, interested parties, and agencies to review and comment on the Draft Supplemental Joint EIS/EIR. All interested parties are encouraged to respond to this notice and provide a current address if they wish to be notified of the Draft Supplemental Joint EIS/EIR circulation.

4. Availability. The Draft Supplemental Joint EIS/EIR is scheduled to be available for public review and comment in summer 2020.

Kimberly M. Colloton,

Brigadier General, U.S. Army, Commanding .