Major Planned Deviation to the Coyote Valley Dam-Lake Mendocino Water Control Manual
Members of the Lake Mendocino Forecast Informed Reservoir Operations (FIRO) Steering Committee have requested a major planned deviation to the Coyote Valley Dam – Lake Mendocino Water Control Manual (WCM). The FIRO effort is led by a steering committee formed in 2014 and consisting of representatives from the Sonoma County Water Agency (Water Agency), Scripps Institute of Oceanography (Scripps), U.S. Army Corps of Engineers (USACE), National Oceanic and Atmospheric Administration (NOAA), U.S. Geologic Survey (USGS), U.S. Bureau of Reclamation and the California Department of Water Resources (DWR).
Lake Mendocino has experienced significantly reduced water supply reliability over the past several years due to a significant reduction of trans-basin transfers into the facility from the Eel River. The goal of FIRO is to help restore some of the diminished water supply reliability without reducing the existing flood protection capacity of Lake Mendocino. Members of the FIRO Steering Committee are requesting USACE approval of a planned major deviation to store additional water above the existing guide curve for the Coyote Valley Dam Lake Mendocino WCM. If approved, this deviation would allow the USACE to store an additional 11,650 acre-feet of water above the existing guide curve, stipulated in the Coyote Valley Dam - Lake Mendocino Water Control Manual, between November 1 and February 28, to restore some of the diminished water supply reliability without reducing the existing flood protection capacity of Lake Mendocino. The requested major deviation to the WCM represents the next phase of the FIRO viability assessment. It is important to emphasize that if water levels are within the storage space allowed by this deviation, the USACE will have the discretion to utilize the additional information provided to inform (but not control) reservoir operations. USACE reservoir operators will retain full operational control and authority, with the FIRO decision support model (DSM) providing an additional tool for operators.
The draft Environmental Assessment (EA) is available for review on the US Army Corps of Engineers San Francisco District's website.
- Major Planned Deviation to the Coyote Valley Dam – Lake Mendocino Water Control Manual - Draft Environmental Assessment
The document is also available for review at:
- Mendocino County Ukiah Branch Library, 105 N. Main St., Ukiah, CA 95482;
- Sonoma County Library Central Library, 211 E. St., Santa Rosa, CA 95404;
- US Army Corps of Engineers’ office at Lake Mendocino; and
- Sonoma County Water Agency 404 Aviation Blvd. Santa Rosa, CA, 95403.
The 30-day public review period for the draft EA extends from July 2, 2018, to July 31, 2018.
All comments postmarked by July 31, 2018, will be considered and incorporated into the final EA, as appropriate. Specific responses will also be included in a comments and responses appendix to the final document.
Please send any questions and comments to: Sonoma County Water Agency, c/o Connie Barton, 404 Aviation Blvd, Santa Rosa, CA 95403 or email at firstname.lastname@example.org
Green Valley Creek High Flow Channel Project
The Sonoma County Water Agency (Water Agency) has developed a proposal to reduce flooding on Green Valley Road west of Graton by removing sediment from the adjacent Green Valley Creek and restoring the creek banks with native vegetation. Pursuant to the California Environmental Quality Act, the Water Agency released a Draft Initial Study and Negative Declaration (IS/ND) for the project on June 22. The public is invited to provide comment on the project before July 24.
Green Valley Creek experiences recurring flooding, leading to extended road closures or hazardous driving conditions on Green Valley Road, stranded fish and wildlife species, and damage to the roadway and adjacent farmland. In recent years, flooding has become worse, lasting longer, causing more damage, and occurring with greater frequency. The proposed project would excavate and maintain channels in the creek and install native plants along the banks to reduce flooding of Green Valley Road and nearby properties and improve aquatic habitat. The project is expected to be implemented in fall 2018. Annual dry season maintenance would occur as needed for five years.
“Last year, Green Valley Road was closed for over three weeks due to flooding,” said Water Agency Director Lynda Hopkins. “The project would make Green Valley Road safer for the communities who rely on it, as well as the fish and wildlife who rely on the creek.”
The project would involve clearing blackberry understory from the creek and an adjacent area in order to establish a temporary access road across a dry channel; excavating sediment from the existing creek and installing a high flow channel through a gravel bar; and planting native species along its banks. Although construction is likely to temporarily disturb fish and wildlife, over the long term the project would improve fish passage, reduce the number of fish stranded by receding floodwaters, improve habitats for other aquatic species, and support healthier habitats downstream by decreasing sediment flows from the area.
An electronic copy of the Draft IS/ND is available at www.scwa.ca.gov/environmental-documents. Hard copies of the Draft IS/ND are available for purchase by request at 707-547-1900 or at the Water Agency’s administrative office (404 Aviation Boulevard, Santa Rosa). Hard copies are also available for public viewing at the following locations:
- Sonoma County Water Agency: 404 Aviation Blvd Santa Rosa, CA 95403
- Sebastopol Regional Library: 7140 Bodega Avenue, Sebastopol, CA 95472
An Initial Study is a preliminary analysis of a project’s potential environmental impacts used to determine whether a Negative Declaration or an Environmental Impact Report will be prepared. The Initial Study is intended to provide a clear understanding of the environmental impacts associated with the construction and operation of the proposed project for decision-makers, responsible and trustee agencies under CEQA, and the public. If an Initial Study identifies potentially significant impacts but the project is modified or revised to clearly mitigate the impacts, a Mitigated Negative Declaration may be prepared. If an Initial Study concludes that a project may have a significant effect on the environment, an Environmental Impact Report should be prepared.
Public Comments at Board of Director Meetings:
2:00 P.M. on days when the Board of Directors meet.
PUBLIC COMMENT ON MATTERS NOT LISTED ON THE AGENDA BUT WITHIN THE SUBJECT MATTER JURISDICTION OF THE BOARD AND ON BOARD MEMBER REPORTS (Comments are restricted to matters within the Board’s jurisdiction. The Board will hear public comments at this time for up to twenty minutes. Each person is usually granted time at the discretion of the Chair. Any additional public comments will be heard at the conclusion of the meeting. While members of the public are welcome to address the Board, under the Brown Act, Board members may not deliberate or take action on items not on the agenda.)
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