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893 Blanco Circle, Salinas, CA 93901 - Phone: (831) 755-4860 - FAX: (831) 424-7935 - Emergency After Hours (831) 796-1166 - Email

Fish Monitoring

River Rotary Screw Trap
  Nacimiento river rotary screw trap

In April 2010, the MCWRA completed the final construction piece of the Salinas Valley Water Project (SVWP), the Salinas River Diversion Facility (SRDF). The SRDF provides a means for the MCWRA to divert surface water off the Salinas River, blend it with recycled water and deliver it to the agricultural growers in the Castroville area of Monterey County. This allows for the reduction, if not cessation, of utilizing supplemental groundwater wells for irrigation purposes and thereby reducing seawater intrusion. As a result of this, the MCWRA supply’s water from Nacimiento and San Antonio Reservoirs to the SRDF via the Salinas River during the irrigation season from April to October. The construction of the SVWP required permits from several regulatory agencies. The 404 permit issued by the U.S. Army Corps of Engineers contained a Biological Opinion from the National Marine Fisheries Service that included requirements for on-going monitoring for threatened distinct population segment, South Central California Coast Steelhead trout (Oncorhynchus mykiss). The MCWRA provides annual reports to NMFS to document the monitoring program results.


  Arroyo Seco juvenile rearing assessment using snorkel surveys

The three main goals of the fish monitoring program are (1) to quantify the presence of the threatened steelhead trout in the lower Salinas River system (population monitoring), (2) to monitor river flows to ensure adequate water for fish passage (migration monitoring) and (3) to monitor water quality to determine habitat suitability (habitat monitoring). Steelhead are anadromous, which means they spend their adult life in the ocean, and then return to their natal freshwater rivers or streams to breed (called spawning). Spawning occurs in the tributaries of the Salinas River. Unlike other Pacific salmonids, they can spawn more than one time (called iteroparity), so they must swim back downstream to the ocean. Juvenile steelhead spend 1 to 4 years growing and developing (called rearing) in the tributaries, then “out-migrate” to the Ocean. Migrations can be hundreds of miles for both juveniles and adults and the mainstem of the Salinas River is used for this journey. The Salinas River system is one of four biogeographic regions to support the full lifecycle of this distinct population segment of California steelhead.