Delta Projects

Decker Island is located in the Sacramento-San Joaquin River Delta along the Sacramento River. We are undertaking the restoration of the Decker Island Tidal Habitat Restoration Project in conjunction with California Department of Fish and Wildlife (CDFW) to enhance roughly 140 acres of established emergent wetland with muted tidal connectivity to Horseshoe Bend, and uplands to fully tidal habitat. 

Planning is ongoing and the mitigated Negative Declaration has been finalized. Most permits have been obtained and design is approximately 60 percent completed.

The project consists of 3 main elements:  

1. Lowering a 300 foot section of levee at the northern end of the Island to internal elevation would create a flow through system that would increase access for fish and inhibit the establishment of invasive vegetation
2. Reconfiguring the internal berms would assist in moving water on and off site and would provide upland habitat for wildlife within the existing tidal wetland
3. Widening the existing breach at the southern end of the Island that would provide full tidal access to the site

The project’s restoration activities would result in the enhancement of 115 acres of tidal wetland, and restoration of 22 acres of tidal wetland.

In partnership with Ecosystem Investment Partners,  the Fish Restoration Program and the Division of Multibenefit Initiatives are undertaking a multi-benefit tidal restoration project at Lookout Slough, located in the Cache Slough Region northwest of Liberty Island. The project aims to restore the approximately 3,400-acre site to a tidal wetland, creating habitat and producing food for Delta Smelt and other listed fish species. In addition to the restoration of important tidal wetland habitat, the project will also provide flood protection by expanding flood conveyance and storage for the Yolo Bypass.

The project goals are to:

• Create and maintain a diverse landscape of intertidal and associated subtidal habitat that supports habitat elements for native species and improved food productivity within the project area.
• Design and implement a project that also supports viable populations of special status aquatic and terrestrial species.
• Provide additional flood storage and conveyance within the Yolo Bypass to reduce the chance of catastrophic flooding and protect existing nearby infrastructure (e.g., agriculture, power, and human habitation).

Restoration actions in the proposed project include:

• Construction of a new setback levee along the northwestern and northern sides of the project site.
• Breaching of exterior levees at multiple locations around the site.
• Degradation of Shag Slough Levee to match the elevation of a 10-year storm event.
• Excavation of tidal channels throughout the project site.
• Restoration of native habitat through grading, fill placement, and natural revegetation.

The project’s restoration activities will restore tidal action with an estimated 3,000 habitat acreage credits for Delta Smelt.

On November 3, 2020, the Department of Water Resources certified the Environmental Impact Report (EIR) for the Lookout Slough Tidal Habitat Restoration and Flood Improvement Project and filed a Notice of Determination with the Governor’s Office of Planning and Research.  

Project Documents and Links

• Notice of Determination
• Final Environmental Impact Report for Lookout Slough Tidal Habitat Restoration and Flood Improvement Project 
• Draft Environmental Impact Report for Lookout Slough Tidal Habitat Restoration and Flood Improvement Project
• Revised Final Environmental Impact Report for Lookout Slough Tidal Habitat Restoration and Flood Improvement Project

Prospect Island is in the Cache Slough Complex (CSC) immediately east of the southern end of the Yolo Bypass, in the Sacramento-San Joaquin River Delta. We are undertaking the restoration of the Prospect Island Tidal Habitat Restoration Project in conjunction with CDFW to convert roughly 1,609 acres of flooded uncultivated land to fully tidal habitat. 

Planning is ongoing. Public draft of the EIR has been completed and circulated for public review. The design is approximately 65percent completed and USACE 404 permit application and USFWS and NMFS Biological Assessments have been completed and submitted.

Restoration includes:

• Interior grading
• Vegetation management
• Possible clean fill import for subsidence reversal
• Possible weir installation
• Breaching of exterior levees
• Addressing various property considerations
• Monitoring  as part of a science- based adaptive management plan

The project’s restoration activities will restore tidal action with an estimated 1,360 habitat acreage credits.

After 2 years, which would allow time for the re-vegetation of disturbed soils, the site will be breached to allow full tidal action. Construction of the initial restoration activities is estimated to begin in June 2018. 

 

 

We are undertaking the restoration of the Winter Island Tidal Habitat Restoration Project in conjunction with CDFW to restore roughly 586 acres of muted brackish wetlands with muted tidal connectivity to fully tidal habitat. 

Directly north of the City of Pittsburg, Winter Island is separated by the New York Slough and boarded the by the Broad Slough, Suisun Bay, and the Middle Slough. A confluence of the Sacramento and San Joaquin Rivers is located north of Winter Island

Planning is ongoing. The Project consists of 3 main elements:  

1. 100 foot breach at the southern water control structure
2. Excavation to widen an existing eastern channel
3. Removal of the northern water control structure with no breach widening

The project is on schedule to complete the CEQA document by August 2018 and obtain permits by February 2019. The project’s restoration activities will restore tidal action with an estimated 480 habitat acreage credits.  

Construction of the initial restoration activities is estimated to begin in August 2019.