Skinner Evaluations and Improvements Study (SEIS)

At the John E. Skinner Delta Fish Protective Facility up to 15 million fish a year are saved from pumps that lift water into the California Aqueduct before they are returned to the Delta. The facility is named for John E. Skinner, a former California Department of Fish and Wildlife biologist who was a national authority on protective fish facilities and striped bass research. Today, we continue to study fish behavior and movement patterns, evaluate the effectiveness of predator management actions, and evaluate the effectiveness of fish protection facilities and actions. Our research allows us to improve fish survival in the water delivery system.


The goals of this study are to:

  1. Evaluate pre-screen losses of salmonids in Clifton Court Forebay to evaluate the effectiveness of predator management actions including predator relocation,
  2. Evaluate fish losses (Salmonids and juvenile Longfin Smelt) through the primary and secondary louvers, and holding tanks of the Skinner Fish Facility, and evaluate hydraulic conditions within the facility, and
  3. Evaluate fish behavior and movement patterns of salmonids as they are entrained through the radial gates, traverse the forebay, and are eventually salvaged at the Skinner Fish Facility to develop methods to improve survival rates.


This project is required to comply with the requirements of the National Marine Fisheries Services Biological Opinions and the conditions of the Department of Fish and Wildlife’s Incidental Take Permit.

Longfin Smelt Efficiency Study

The Delta is home to many fish and wildlife species including the Longfin Smelt which has been identified as a threatened and endangered fish. As part of our work to better understand and monitor fish lifecycles, the Longfin Smelt Efficiency Study researches how efficiently DWR facilities recover Longfin Smelt. The study involves releasing a known number of marked, hatchery-raised, post-larval Longfin Smelt into the State Water Project and then recapturing them at the John E. Skinner Delta Fish Protective Facility. Data collected as a part of this study will add to our knowledge about Longfin Smelt and the capability of our facilities to protect fish and be used to inform management and regulatory entitiesThis study is required by the California Department of Fish and Game as a part of the California Endangered Species Act Incidental Take Permit issued to DWR.

Contact Information

Ryan L. Reeves, P.E.
Fisheries Infrastructure and Operations Branch
Division of Integrated Science and Engineering