2010-10103. Notice of Intent To Prepare a Draft Environmental Impact Statement and Dam Safety Assurance Program Modification Report for the Martis Creek Dam Project, Nevada County, CA

AGENCY:

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

ACTION:

Notice of Intent.

SUMMARY:

Pursuant to the National Environmental Policy Act of 1969, as amended, the U.S. Army Corps of Engineers, Sacramento District (Corps) intends to prepare a draft Environmental Impact Statement (EIS) for the Federal action to remediate seismic, seepage, and hydrologic dam safety concerns at the Martis Creek Dam. Martis Creek Dam is located about two miles upstream of the confluence of Martis Creek and the Truckee River, and about three miles east of Truckee, in Nevada County, CA. The Truckee River flows through Reno, Nevada and into Pyramid Lake, NV. The proposed action is being conducted through the Corps' Dam Safety Assurance Program (DSAP) for the evaluation of existing dams.

ADDRESSES:

Current and archival information regarding the Martis Creek DSAP Project can be obtained from the following Web site address: http://www.spk.usace.army.mil/​projects/​civil/​Martis_​Creek/​Index.html. Questions or comments regarding the Martis Creek DSAP Project may be submitted through this Web site, or written questions or comments can be submitted by mail to Ms. Mariah Garr, U.S. Army Corps of Engineers, Sacramento District, Attn: Planning Division (CESPK-PD-R), 1325 J. Street, Sacramento, CA 95814. Requests to be placed on a mailing list may also be submitted through the Web site or to the address provided.

FOR FURTHER INFORMATION CONTACT:

Ms. Mariah Garr at [phone], e-mail: [e-mail], or by mail to (see ADDRESSES).

SUPPLEMENTARY INFORMATION:

1. Background Information. Based on the current engineering knowledge, the Corps has determined that the Martis Creek Dam has a high risk of failure due to significant existing seismic, seepage, and hydrologic issues. Compounding this risk is the large population downstream within the inundation zone, specifically the Reno-Sparks Metropolitan Area. An external peer review panel, commissioned by the Corps, confirmed that the Corps' Class I designation “Urgent and Compelling” is appropriate for the Martis Creek Dam for the following reasons:

a. Foundation and abutment seepage and piping.

b. The dam's drain blanket is not performing as intended;

c. The spillway is hydraulically inadequate;

d. The site is in a high seismic zone and it is probable that the dam and spillway are seismically inadequate;

e. High probability of structural failure, leading to potential life and economic loss.

The panel recommended short-term risk reductions measures, such as maintaining the current reservoir pool restriction elevation of 5,780 feet for normal conditions, 58 feet below gross pool. The panel also recommended long-term risk reduction measures including completion of on-going studies of hydrologic, seismic, and geophysical conditions, and improving the existing instrumentation to ensure adequate monitoring and to provide suitable baseline information.

2. Remediation Alternatives. The draft EIS will address an array of remediation alternatives that are necessary to prevent loss of life, extensive downstream damage, functional loss of the project, and the loss of all project benefits. The exact nature and extent of the remediation alternatives will be determined based on the results of on-going geotechnical and engineering studies, public and agency input during the scoping period, and preparation of the draft EIS.

3. Issues To Be Addressed. The draft EIS will address environmental issues concerning the remediation alternatives proposed. Issues will be identified based on public input during the scoping process and during the preparation of the draft EIS. Issues initially identified as potentially significant include, but are not limited to: soils and seismicity, hydrology and water quality, noise and vibration, air quality, socioeconomics, water supply, land use, recreation, visual and aesthetic resources, traffic and transportation, historical and cultural resources, vegetation and wildlife, special status species, and fisheries.

4. Public Involvement. Public scoping meetings will be held in June or July 2010 at specific locations to be announced within the local Martis Creek DSAP project area, in Truckee, CA. The purpose of the public scoping meetings will be to present information to the public regarding the array of remediation alternatives proposed that may be addressed in the draft EIS, receive public comments, and solicit input regarding environmental issues of concern to the public. These meetings are intended to initiate the process to involve concerned individuals, and local, State, and Federal agencies. The public scoping meeting place, date, and time will be advertised in advance in local newspapers, and meeting announcement letters will be sent to interested parties. Written comments may also be submitted via the Web site or mailed to (see ADDRESSES).

5. Availability of the Draft EIS. The Corps intends to issue the draft EIS in April 2011. The Corps will announce availability of the draft EIS in the Federal Register and other media, and will provide the public, organizations, and agencies with an opportunity to submit comments to be addressed in the final EIS.

Dated: April 19, 2010.

Thomas Chapman,

COL, EN, Commanding.