FINAL ◦ JUNE 2020 Initial Study/ Mitigated Negative Declaration Grand Island Levee Erosion Repair Project State Clearinghouse No. 2020019085 PREPARED FOR PREPARED BY Reclamation District No. 3 Stillwater Sciences P.O. BOX 1011 2855 Telegraph Avenue, Suite 400 Walnut Grove, CA 95690 Berkeley, CA 94705 and MBK Engineers 455 University Avenue, Suite 100 Sacramento, CA 95825 Stillwater Sciences FINAL Initial Study/Mitigated Negative Declaration Grand Island Levee Erosion Repair Project Suggested citation: Stillwater Sciences and MBK Engineers. 2020. Initial Study/Mitigated Negative Declaration for the Grand Island Levee Erosion Repair Project, Sacramento County, CA. Final. Prepared by Stillwater Sciences, Berkeley, California and MBK Engineers, Sacramento, California for Reclamation District No. 3, Walnut Grove, California. Cover photo: Grand Island’s Project levee, waterside. June 2020 Stillwater Sciences i FINAL Initial Study/Mitigated Negative Declaration Grand Island Levee Erosion Repair Project PROJECT SUMMARY Grand Island Levee Erosion Repair Project Reclamation District No. 3 CEQA lead agency name P.O. BOX 1011 and address Walnut Grove, CA 95690 • California Department of Water Resources CEQA responsible • Central Valley Regional Water Quality Control Board agencies • California Department of Fish and Wildlife • California State Lands Commission Mike Kynett Project Engineer, or Tina Anderson Project Manager Contact person and phone MBK Engineers number 455 University Avenue, Suite 100 Sacramento, CA 95825 Office: (916) 456-4400 Fax: (916) 456-0253 Project location Grand Island, Sacramento-San Joaquin Delta, Sacramento County Reclamation District No. 3 Project sponsor’s name P.O. BOX 1011 and address Walnut Grove, CA 95690 (916) 776-1945 Zoning Recreation Repair approximately 1,700 ft of Grand Island’s levee system while restoring Description of Project riparian habitat by establishing a waterside berm planted with native species. Surrounding land uses The Project is adjacent to Steamboat Slough to the north, a dredged spoils/fill area to and setting the south, and farmed lands to the east • California Department of Water Resources, funding under the Flood System Repair Project • U.S. Army Corps of Engineers (Clean Water Act Section 404 Permit) • Central Valley Regional Water Quality Control Board (Clean Water Act Section Other public agencies 401 water quality certification) whose approval may be • California Department of Fish and Wildlife (Lake and Streambed Alteration required (e.g., permits, Agreement) financing, or participation • agreement) U.S. Fish and Wildlife Service and National Marine Fisheries Service (Endangered Species Act Section 7 consultation regarding federally protected species) • Central Valley Flood Protection Board (maintenance notification) • California State Lands Commission June 2020 Stillwater Sciences ii FINAL Initial Study/Mitigated Negative Declaration Grand Island Levee Erosion Repair Project PROPOSED MITIGATED NEGATIVE DECLARATION Project: Grand Island Levee Erosion Repair Project Lead Agency: Reclamation District No. 3 Project Location: Grand Island is located in the Sacramento-San Joaquin Delta, between the cities of Walnut Grove, Rio Vista, and Courtland in Sacramento County, California. The Project is located at the southwest portion of Grand Island along the left river bank of Steamboat Slough between stations 562+00 and 579+00 (Levee Mile 10.78 and 11.02) Project Description: Reclamation District No. 3 plans to repair approximately 1,700 feet of levee to address critical erosion, bank loss, and waterside instability by placing rock, while restoring riparian habitat by establishing a waterside berm planted with native species. The Project will include placing rock on the waterside levee slope and reconstructing a section of the bank with a soil planting berm and rock containment berm. The Project will reestablish the authorized waterside levee slope geometry by replacing the bank and associated function that was part of the original federal levee. Findings: An Initial Study has been prepared to assess the Project’s potential effects on the environment and the significance of those effects. Based on the Initial Study, Reclamation District No. 3 has determined that the Project will not have any significant impacts on the environment once mitigation measures included in the Project design are implemented. This conclusion is supported by the following findings: • The Project will result in no impacts on: agricultural and forest resources, cultural resources, land use and planning, mineral resources, noise, population and housing, public services, recreation, transportation and traffic, tribal cultural resources, utilities/service systems, and wildfire. • The Project will result in less-than-significant impacts on: aesthetics, air quality, energy, geology and soils, greenhouse gas emissions, hazards/hazardous materials, and hydrology/water quality. • Mitigation is included in the Project design to reduce potentially significant impacts to less-than-significant levels for: biological resources. Mandatory Findings of Significance: • The Project will not substantially degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal, or eliminate important examples of the major periods of California history or prehistory. • The Project will not have cumulatively considerable environmental effects. • The Project will not have environmental effects which would cause substantial adverse effects on human beings, either directly or indirectly. • The Project will not achieve short-term environmental goals to the disadvantage of long- term environmental goals. • No substantial evidence exists that the Project will have a negative or adverse effect on the environment. June 2020 Stillwater Sciences iii FINAL Initial Study/Mitigated Negative Declaration Grand Island Levee Erosion Repair Project Proposed Mitigation Measures: Mitigation measures included in the Project to avoid or minimize potential environmental impacts are included in the attached Initial Study, which is hereby incorporated and fully made part of this Mitigated Negative Declaration. Implementation of these mitigation measures will reduce the potential environmental impacts of the Project to a less-than-significant level. Reclamation District No. 3 has agreed to implement each of the identified mitigation measures, which will be adopted as part of the Mitigation Monitoring and Reporting Program. Determination In accordance with Section 21082.1 of the California Environmental Quality Act (CEQA), Reclamation District No. 3 has independently reviewed and analyzed the Initial Study and proposed Mitigated Negative Declaration for the Project and finds that the Initial Study and proposed Mitigated Negative Declaration reflects the independent judgment of Reclamation District No. 3. The lead agency further finds that the Project mitigation measures will be implemented as stated in the Initial Study and Mitigated Negative Declaration. This Mitigated Negative Declaration is filed in accordance with CEQA and state CEQA guidelines. I hereby approve this Project: _____________________________________ _______________________ Reclamation District No. 3 Date June 2020 Stillwater Sciences iv FINAL Initial Study/Mitigated Negative Declaration Grand Island Levee Erosion Repair Project TABLE OF CONTENTS 1 INTRODUCTION .................................................................................................................. 1 1.1 Project Location ........................................................................................................... 1 1.2 Project Area ................................................................................................................. 1 1.3 Project Description ...................................................................................................... 4 1.3.1 Project purpose ...................................................................................................... 4 1.3.2 Project design ........................................................................................................ 4 1.3.3 Site preparation ..................................................................................................... 5 1.3.4 Imported fill ........................................................................................................... 7 1.3.5 Planting .................................................................................................................. 7 1.3.6 Erosion control ...................................................................................................... 7 1.3.7 Equipment and staging .......................................................................................... 7 1.3.8 Construction schedule and timing ......................................................................... 9 1.4 Conservation Measures ................................................................................................ 9 1.4.1 Best Management Practices ................................................................................... 9 1.4.2 Biological Mitigation Measures .......................................................................... 12 2 ENVIRONMENTAL IMPACTS ........................................................................................