Project D.15 Recreate Shallow Water Habitat in the Delta Migration Routes

Juvenile winter run are generally the first to emigrate to the Delta, with the first arriving in November or December.  They rear in the Delta for months until moving to the bay and out to the ocean. Good rearing habitat in the Delta is in short supply, in part due to the extensive channel straightening, rip rapping and armoring of channels there.  In addition, subsidence of Delta farmlands means most are now protected by hardened levees, further reducing available native shallow water rearing habitat. The 2009 salmon biop recognized this shortage as being harmful to winter run and required the water agencies to restore more shallow water habitat in the Delta, something they’ve been very slow to do.

Importantly, these sites must be designed to avoid creation of predatory fish habitats and be established in locations likely to be utilized within or adjacent to the principal fish migration corridors. Much state and federal work, mostly studies and permitting, is underway. Some good shallow water habitat still exists in the northwest Delta near the Cache Slough complex.  The CVPIA restoration fund, at GGSA’s recommendation, has committed funding to expedite this restoration.

This project proposes to add GGSA’s support and resources in whatever ways are needed to expedite restoration of more Delta shallow water habitat currently underway through state and federal water agencies.

Related Developments
Fall 2018

Brought to you by: 
California Department ofWater Resources (DWR) and 
California Department ofFish and Wildlife (CDFW)

The Department of WaterResources (DWR) and the California Department of Fish and Wildlife (CDFW) FishRestoration Program (FRP) addresses specific habitat restoration requirementsof the US Fish and Wildlife Service (USFWS) and National Marine FisheriesService (NMFS) biological opinions (Biological Opinions) for State WaterProject (SWP) and Central Valley Project (CVP) operations.

Winter Island Tidal Habitat Restoration Mitigated Negative Declaration

The Winter Island Tidal Habitat Restoration Project Mitigated Negative Declaration (MND) was released on August 10, 2018 and submitted to the State Clearinghouse to initiate the 30-day public review period. Public comments were accepted through September 10th and staff is currently working to respond to comments. The MND can be found on DWR’s website at https://water.ca.gov/-/media/DWR-Website/Web-Pages/News/Public-Notices/Files/Winter-Island-Tidal-Restoration-Project/Winter-MND-August-2018.pdf?la=en&hash=6AE530BE0F038C01E048BD5CC6BF76FD935655DD. All other environmental permits have been submitted and the project is on schedule for construction in fall 2019.

Questions about the Winter Island project should be sent to the project manager, Joy Khamphanh (manisay.khamphanh@water.ca.gov).

Decker Island Restoration Project Construction

Construction began at Decker Island for the Decker IslandRestoration Project in mid-August 2018 and was completed in early October 2018.The approximately 140 acres was acquired by the Fish Restoration Program in2015 for tidal restoration. The goal of the Project is to restore unrestrictedtidal connectivity to the interior of Decker Island, creating a tidal wetland,associated high marsh, and riparian habitat on the site to benefit native fishspecies.

Decker Island project restores 140 acres of tidal wetland habitat, aims to boost fish survival rates

Published: November 15, 2018

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Aerial of Decker Island. DWR/2018

Editor’s note: The following article is part of a continuing series highlighting the California EcoRestore Initiative, which seeks to restore 30,000 acres of habitat in the Sacramento-San Joaquin Delta by 2020. California EcoRestore is an umbrella program that includes habitat restoration efforts implemented and funded by the Departments under California Natural Resources Agency including Department of Water Resources, Department of Fish and Wildlife, and the Delta Conservancy.

DWR recently completed construction that transforms an island in the heart of the Sacramento-San Joaquin Delta from a managed leveed site to an open tidal wetland reminiscent of the historical landscape.

Decker Island (Solano County) is located amidst the largest estuary on the West Coast, between freshwater and saltwater, where the endangered Delta smelt are concentrated. Over time, the Delta ecosystem and food web that native fish species depend on has been greatly diminished.

The Decker Island Tidal Habitat Restoration Project, which broke ground in August 2018, converts an existing wetland into tidal habitat. Under the plan, DWR breached levees along the perimeter of the 140-acre site, allowing water from the Sacramento River to move through the marshland. As the water flows out of the marshland, it carries microscopic plankton, plant particles, and other nutrients across the Delta’s waterways, where the tiny bits are eaten by Delta smelt and other fish and wildlife species.  

“These tidal wetlands are the bread baskets of the Delta. This is where the basis of the food web is created,” said Dennis McEwan, Chief of the State Water Project Mitigation and Restoration Branch within DWR.

More than a century ago, levee systems were built up to protect agricultural land and urban areas from the seasonal and tidal waters. Since the 1800s, tidal wetland habitat in the Delta has declined from an estimated 350,000 acres to about only 10,000 acres. This loss of habitat has contributed to the steep decline of native fish and wildlife species. The restoration projects under California EcoRestore, such as this effort on Decker Island, seek to reverse this trend by providing the habitat and food sources needed to boost fish survival rates.

Decker Island is one of 13 projects planned and implemented by DWR’s Fish Restoration Program charged with restoring 8,000 acres of tidal wetland habitat in the Delta and Suisun Marsh, as required mitigation for the State Water Project and Central Valley Project long term operations. This effort has been a close partnership between DWR and the California Department of Fish and Wildlife (CDFW). CDFW will carry out the on-site biological monitoring to ensure the site functions as it was designed and to inform future restoration efforts.

Prospect Island draft Environmental Impact Report

The Prospect Island Tidal Habitat Restoration Project released adraft Environmental Impact Report (EIR) for public review in the fall of 2016.Several public comments were received, reviewed, and addressed. DWR ispreparing a partial recirculation of the DEIR and plans to finalize the EIR byearly 2019.

Yolo Flyway Farms Construction

Construction at Yolo Flyway Farms was completed on September 28, 2018. The approximately 294 acres of tidal marsh habitat restored for this project is a result of a Request for Proposals (RFP) contract awarded to Reynier Fund, LLC in August 2017. This is the first of FRP’s RFP projects to be completed.

Questions about the Yolo Flyway project should be sent to the project manager, Bonnie Irving (Bonnie.Irving@water.ca.gov).

Lookout Slough

The DWR Fish Restoration Program has entered into a contract with Ecosystem Investment Partners, an investment firm specializing in restoration and conservation projects, to deliver a tidal habitat restoration project called Lookout Slough. When completed in 2022, this project is expected to produce approximately 3,000 acres of tidal habitat to benefit Delta smelt and other native species.

Questions about the Lookout Slough project should be sent to the project manager, Bonnie Irving (Bonnie.Irving@water.ca.gov).

Revegetation Research Projects

FRP staff are collaborating with UC Davis on two research projects focusing on revegetation during restoration planning as an integrated pest management method for invasive plant species in tidal wetlands. This research will be testing the hypothesis that active revegetation using native plant species during restoration efforts can effectively inhibit invasive plant species establishment. The study will utilize different plant species, stages, and environmental conditions to test this hypothesis. Objectives of this study are to decrease costs for maintenance/adaptive management of invasive species and reduce rates of invasive aquatic species establishment within restoration areas to improve fish habitat.

Research project installation was completed at Dutch SloughSeptember 12, and at Bradmoor September 30. The research plots will be gardenedand maintained (replacing transplants, pulling weeds) regularly until the endof November. After this, plots will be monitored for three years, primarilyfocusing on invader metrics (rate of invasion, type of invaders, and fecundityof invader) and community metrics (species richness, species diversity, andtransplant survival and health of plants).