The project would plan for the restoration of a degraded 400-acre riparian/wetland system along the Santa Clara River (SCR) in Fillmore, CA. The project is located within an ecologically productive reach of the SCR floodplain which supports emergent marshes, vernal wetlands, riparian forests and extensive oak woodlands. Local hydrology and soil properties are also influenced by previous and adjacent upland agriculture. Historically, artesian flows in this reach of the SCR supported one of most extensive wetlands in the floodplain referred to as the ‘Cienega’ and ‘Sespe Cienega’. The planning effort will focus on properties owned by California Department of Fish and Wildlife (CDFW; Cienega Springs/Fish Hatchery) and The Nature Conservancy (TNC; Shiells- Somers). Owing to the location of the these properties between restored conservation properties, and ownership status and size of the CDFW/TNC/mitigation-owned areas, we have a unique opportunity to re-establish native riparian and aquatic habitats that mimic, if not fully re-create, the rare wetlands that were historically present at this location. This effort is part of a SCR program, including University of California, Santa Barbara (UCSB), TNC, and the Santa Clara River Conservancy (SCRC) to plan, develop funding for, and implement restoration and ecosystem monitoring of the Sespe Cienega and surrounding floodplain. The highly productive and diverse habitats in the project area provide critical habitat for wildlife, as well as serve as corridors for movement of larger animals. Listed and special status species that will benefit from this project include state and federally endangered least Bell’s vireo (Vireo bellii pusillus), state and federally endangered southwestern willow flycatcher (Empidonax traillii extimus), federally endangered arroyo toad (Anaxyrus californicus), and federally endangered steelhead trout (Oncorhynchus mykiss). As part of the planning project for the 394-acre Sespe Cienega restoration program, we propose to evaluate and summarize available scientific data/information to support development of project permitting, including USFWS ESA evaluation, and CDFW California Environmental Quality Act (CEQA) consultation and Lake and Streambed Alteration Agreement permit application. We will review and synthesize the scientific and technical literature related to the site as a starting point for the planning effort, to guide ‘on the ground’ environmental data collection efforts, and to assemble the necessary data/information for regulatory permit development. Emphasis will be placed on reviewing information available for the river reach that contains the extent of the historical Cienega, but will also consider the site within the context of the floodplain and watershed to facilitate a landscape perspective. Studies of other watersheds that can provide insight for the current planning process will also be considered.