Located in Santa Barbara County the Santa Ynez River watershed encompasses approximately 897 square miles, draining from the river’s headwaters in the Santa Ynez Mountains westward through the Santa Ynez Valley before emptying directly into the Pacific Ocean. With a maistem length of approximately 92 miles, the Santa Ynez River passes through the cities of Santa Ynez, Solvang, Buellton, and Lompoc. According to the United States Geological Survey (USGS), it is a fourth order river that has approximately 2,077 miles of total stream length divided between 1,663 intermittent miles, 350 perennial miles, and 63 miles of manmade channels. Elevations range from 4 feet at the head of the estuary to 6,820 feet in the Santa Ynez Mountain Headwaters.
The Santa Ynez River watershed has a Mediterranean climate with alternating wet and dry cycles. Most of the rainfall occurs in the winter; however yearly rainfall amounts can be incredibly variable. In addition to temporal variation in rainfall, average annual rainfall varies greatly throughout the watershed. Headwaters often receive almost twice as much rainfall as the lower watershed. Average annual rainfall for the City of Santa Ynez is 16.20in (1951-2012), whereas for Gibraltar Reservoir the average annual rainfall is 28.11in (1951-2012) (Santa Barbara County Public Works).
Stream flows within this watershed are highly influenced by precipitation events; therefore the variable rainfall amounts can lead to a pattern and magnitude of stream flow that is seasonally and interannually variable. Many streams will have high flows during wetter winter months and low to no flows during the drier summer months.
The Santa Ynez River has been identified as a Core 1 population in the NMFS Recovery Plan for Southern California Steelhead, indicating that it is a high priority for recovery actions. This once vital river had the largest run of steelhead in Southern California prior to the construction of three large dams between 1920 and 1953. After the construction of these dams access to upstream spawning grounds and juvenile rearing habitat was extremely diminished. In addition water diversion dramatically limited flows and changed the hydrologic function of the river.
The Pacific States Marine Fisheries Commission (PSFMC), the California Department of Fish and Wildlife (CDFW), along with the NMFS Southwest Regional office in Long Beach, have determined that the assessment of habitat and population status within the Santa Ynez River watershed will play an important role in the recovery of this species. This information will be used to protect existing spawning and rearing habitat, as well as restore critical habitat.