Yolo Flyway Farms Tidal Restoration Project
The Yolo Flyway Farms Tidal Restoration Project is located at the southern end of the Yolo Bypass within the Cache Slough Complex. Reynier Fund, LLC undertook this project to promote floodplain access and restore tidal wetlands to enhance and create habitat for special status fish.
The primary project objectives were:
- Enhance regional food web productivity in support of delta smelt recovery;
- Provide rearing habitats for out-migrating salmonids;
- Support a broad range of other aquatic and wetland-dependent species, including Sacramento splittail; and
- Provide ecosystem functions associated with the combination of Delta freshwater aquatic/tidal marsh/floodplain/seasonal wetland/lowland grassland interfaces that existed historically.
To meet the project objectives, cbec developed a climate change resilient design to maximize hydrologic connectivity, and optimize residence time diversity during tidal conditions and frequent flood events. In support of design, cbec developed a 2D hydrodynamic model to evaluate a suite of alternatives for a range of flow conditions. Construction documents were developed based on the most effective alternative, and featured designs focused on swale and wetland terrace excavation, and selective agricultural berm leveling. The project involved minimal excavation of approximately 65,000 cubic yards of soil. This would provide access to emergent marsh and floodplain habitats connected to the adjoining tidal system via breaching of existing agricultural berms, while simultaneously creating an interior tidal channel network. The excavated material was then placed on existing upland areas on the project site, then planted with salvaged emergent marsh vegetation. cbec provided construction observation in late 2018, and survey and quality control services during post-project monitoring in 2019.
Not all levee breaches are cause for concern! Here is a time-lapse of just over an hour of grading activities to complete an intentional breach at Yolo Flyway Farms. Yolo Flyway Farms is a tidal wetland restoration project in the Southern end of the Yolo Bypass that cbec has been working on for several years. The restoration project will allow the land to tidally connect to the Toe Drain, a narrow channel that connects the Yolo Bypass with the Sacramento River. Intended goals of intentional breaches are for protecting valuable areas, draining flooded areas, or giving back land to nature. In this case on the Yolo Flyway Farms Restoration Project, the goal is to restore tidal interaction to enhance and create habitat for special status fish. To meet the project objectives, cbec developed a design to optimize connectivity to tidal fluctuations, developed a 2D hydrodynamic model to simulate alternatives, and construction documents based on the most effective alternative. In addition, cbec is currently providing surveying, observation and quality control services during the construction phase. To keep up to date on this joint effort by the California Department of Water Resources and Reynier Fund, keep an on #cbecFlywayFarms
Posted by cbec eco-engineering on Friday, 18 January 2019
Above is a terrain comparison of the Flyway Farms project site taken in September 2018 shortly after the tidal channel construction (top) and in March 2019, following flood events (bottom).