45-Day Public Comment – Draft SEIR for McCormack-Williamson Tract Levee Modification & Habitat Restoration Project


The California Department of Water Resources announces a 45-day public comment period for the Draft North Delta Supplemental Environmental Impact Report (SEIR) prepared in accordance with the California Environmental Quality Act for the proposed McCormack-Williamson Tract Levee Modification and Habitat Restoration Project (Project) – Phase B (State Clearinghouse No. 2003012112).

GENERAL DESCRIPTION: The project purpose is to implement flood control improvements in a manner that benefits aquatic and terrestrial habitats, species, and ecological processes, and incorporates landscape scale restoration of Delta habitat. The project was previously analyzed in the North Delta Flood Control and Ecosystem Restoration Project (North Delta) EIR prepared by DWR. The North Delta Draft EIR was prepared in 2007 and the Final EIR prepared and certified in 2010. Since certifying the North Delta EIR in 2010, DWR has separated the MWT project into Phases A and B. DWR prepared an addendum to the North Delta EIR and constructed Phase A components in 2018 and 2019. The Phase B project consists of implementing the remaining project components of the larger MWT project. A Supplemental EIR has now been prepared for Phase B and provides supplemental information and analyzes project specific impacts not presented in the North Delta EIR.

The focus of this Supplemental EIR is to evaluate changes in circumstances under which the project is undertaken and new available information since the North Delta EIR was certified in 2010, including changes to the physical environment at MWT from flooding in 2017, subsequent abandonment of agricultural production, and construction of the Phase A project components in 2018 and 2019. Extensive hydraulic modeling was performed using an updated regional model and new flood information from 2017, resulting in changes to the project design. The project changes and/or additions are minor and are proposed to optimize the project to best meet project objectives under the changed conditions and minimize environmental impacts.

The Phase B project consists of levee modifications and habitat restoration. Levee modifications include lowering sections of the MWT East and Southwest Levees and a section of the Mokelumne River Levee and repairing a small section of the MWT West Levee. Habitat restoration consists of enhancing the landside levee slope and habitat for the MWT East and Southwest Levees and modifying landform to restore previous agriculture land to habitats–subtidal open water/shallow subtidal, tidal marsh, and riparian scrub/mixed riparian woodland/valley oak woodland habitats. Additionally, the Phase B project includes decommissioning utilities on MWT, including abandoned gas lines and gas wells and relocating SMUD distribution lines off MWT.

ENVIRONMENTAL IMPACTS: Without mitigation, the Phase B project would have significant or potentially significant impacts on hydrology and water quality; air quality; noise; biological resources; land use, agriculture, recreation, and economics; public health and hazards; and cultural and Tribal cultural resources. Mitigation measures are proposed to reduce all impacts to less-than-significant.

REVIEW: View Draft Supplemental EIR. The public comment period begins February 11, 2022 and closes on March 28, 2022.

Appendices and the North Delta EIR are available upon request. Please email Anitra.pawley@water.ca.gov.

A physical copy of the Draft Supplemental EIR, all references, and its appendices will also be made available upon request at the California Natural Resources Office, located in Sacramento, California. Please call 916-820-7572 to make arrangements for review.

COMMENT SUBMITTAL: Comments regarding the Draft Supplemental EIR should be submitted in writing via email or mail to DWR’s North Delta Program Manager, Anitra Pawley with the subject line “MWT Project Phase B Supplemental EIR”:

California Department of Water Resources

Attn: Anitra Pawley

P.O. Box 942836

Sacramento, CA 94236-0001

E-mail: Anitra.pawley@water.ca.gov


Comments are due no later than 5 p.m. Pacific Time on Monday, March 28, 2022. All comments submitted must include the commenter’s name, mailing address, and phone number. All comments received by DWR are public records, subject to disclosure under the Public Records Act.