The Lower Putah Creek Restoration Project would create a new Lower Putah Creek channel through the Yolo Bypass Wildlife Area (YBWA).

This channel would connect to and enhance the existing restored tidal channel network on the YBWA and provide a new connection between Lower Putah Creek and the Toe Drain, downstream of the Lisbon Weir. The new channel would provide fish passage and habitat for Delta native fish and other native wildlife, including aquatic habitat, seasonally inundated floodplain wetlands, tidal wetlands and riparian habitat.

The project would also expand and enhance tidal wetland habitat within California Department of Fish and Wildlife (CDFW) restored tidal channel network and connect the channel network to the new Lower Putah Creek channel. The project would include the restoration of 20 acres of stream channel, 490 acres of seasonally inundated floodplain, and 90 acres of freshwater tidal marsh habitat. The project area would be excavated to create a low flow channel, lowered floodplain areas, and tidal wetlands.

cbec, working the ESA and Stillwater, evaluated the performance of the Project. cbec monitored storm event flows to develop a calibration data set for the hydrodynamic model. cbec reconstructed the low flow hydrology for Putah Creek to be used in the hydrodynamic model.

The hydrodynamic model TUFLOW, developed during the DWR/USBR Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project EIS/EIR, was used to design the capacity and geometry of the realigned channel to meet fish passage criteria and meet floodplain inundation and duration objectives. Model results were also used to understand potential methylmercury and flood conveyance impacts within the YBWA.