This project will provide funding for preliminary planning and design for restoring fish access to slough and tidal floodplain habitat in three sloughs and tributaries to the lower smith river estuary

This Cooperative Agreement award, totaling $241,000.00, was provided by the U.S. Department of the Interior Fish and Wildlife Service under the National Fish Passage Program (CFDA 15.685). The funds will support preliminary planning and design activities to restore fish access to slough and tidal floodplain habitats in three priority sites along the lower Smith River estuary in California. This includes completing surveys, developing preliminary designs up to 10% for Islas Slough and Spruce Creek, and providing preliminary designs less than 10% for the Upper Tillas Slough. The project will evaluate habitat conditions, potential impacts, and opportunities to create diverse tidal and freshwater habitats to benefit anadromous, marine, and terrestrial species. These preliminary planning and design activities are critical first steps towards restoring over 60 acres and 8,300 feet of coastal freshwater and tidal stream and wetland habitats in the Smith River watershed, which have been significantly degraded since levee construction in the 1970s.

These project sites were identified as a high priority in the smith river plain stream restoration plan and as high priority tasks in the recovery strategy for california coho salmon. This project will fund preliminary planning and design activities to approximately 10 percent for islas slough, and spruce creek in the lower smith river estuary. IT will complete surveys and provide a preliminary design less than 10 percent for upper tillas slough. The project will evaluate habitats at islas slough, spruce creek, and upper tillas slough with topographic and hydraulic assessments that will evaluate beneficial (i.e., habitat creation, sea level rise and flood capacity) and potential detrimental (i.e., flood area and inundation depths) project impacts to ensure design decisions consider community resilience and fish and wildlife benefits. Vegetation assessments will be conducted to support restoration planning. Restoration of the three project sites will create diverse tidal and freshwater habitats across the smith river estuary that will benefit all anadromous species, as well as marine and terrestrial species as natural processes are restored and native vegetation enhanced. At a minimum, the developed plans and preliminary designs at the three project sites are the critical first steps to restoring over 60 acres and 8,300 feet of coastal freshwater and tidal stream and wetland habitats. Since levee construction in the 1970S, islas slough, one of the three project sites, has been reduced from 71 acres in 1942 to 12 acres in 2012 (parish and garwood 2015). A tide gate near the mouth of spruce creek, the second project site, has limited fish access to over 2,000 feet of stream and tidal wetland habitats. An undersized perched culvert on tillas slough, site three, limits tidal connectivity and natural maintenance of in-channel complexity and size as invasive reed canary grass has colonized the entire channel resulting in reduced water quality, in-channel complexity, and natural channel processes, particularly sediment transport, along over 1,500 feet of channel.