Non-Physical Barrier (NPB) for Fish Protection Evaluation: Can an Inexpensive Barrier Be Effective for Threatened Fish?

Project ID: 8740
Principal Investigator: Mark Bowen
Research Topic: Fish Passage and Entrainment
Funded Fiscal Years: 2009 and 2010
Keywords: None

Research Question

* Can a NPB deter Chinook salmon or delta smelt?

A less expensive alternative to positive barrier screens could allow screening of many diversions. In many areas of the Western United States, laws now require that diversions be screened. Reclamation must address these screening issues if we are to continue delivering water.

* How much less expensive is a NPB with sound, air bubble curtain, and strobe light components?

One of our partners (D. Meier) is the director of the Anadromous Fish Screen Program at the U.S. Fish and Wildlife Service (USFWS) in the Central Valley of California. He reports the estimated range in cost for a positive barrier screen in the Central Valley is $6, 000 - $10,000 per cubic foot per second (cfs). The estimated cost of the NPB for a 100 cfs diversion is $195,750--approximately $2,000 per cfs. We have a scale version of such an NPB in our laboratory in Lakewood, Colorado. This NPB is manufactured by Fish Guidance Systems (Winchester, England), who also provided this cost estimate.

Need and Benefit

An advocate or partner (indicated at the beginning line) suggested each of these potential applications.

A. Goyal
In the Central Valley of California, Reclamation operates the Central Valley Project. Recently, the Sacramento-San Joaquin Delta (Delta) pelagic fish have declined significantly (Sommer et al. 2007): striped bass juveniles, longfin smelt, threadfin shad, and delta smelt (Status: Threatened). Spring chinook are also listed as threatened. And in 2008, Fall Chinook salmon exhibited a serious population decline. The diversion of thousands of acre feet of Delta water contributes to these declines.

An effective NPB could be deployed at the confluence of Georgiana Slough and the Sacramento River. An effective NPB could deter Chinook salmon and delta smelt from entering Georgiana Slough, and they would be less susceptible to entrainment to the water diversions in the South Delta. An effective NPB could reduce the number of delta smelt being entrained to the Tracy Fish Collection Facility (TFCF). This would reduce the number of days that the Tracy Pumping Plant cannot divert water by avoiding Red Light. Regulatory agencies would not force the cessation or reduction of pumping if Reclamation never hit Red Light at the TFCF.

D. Meier
Unscreened diversions in the Delta contribute to the loss of Chinook salmon and delta smelt. There are programs to screen these diversions, but still more than 2, 000 remain unscreened. Less expensive screens could lead to more screened diversions faster than what we are currently experiencing. Screening could lead to a reduction in losses of these fish listed above. Improved population size, especially of delta smelt, could relax operational constraints on the California Valley Project.

Reclamation contributes between two and eleven million dollars per year for the construction of fish screens in California's Central Valley. That value is likely to increase in the future. Some of this money could be saved with a less expensive screening option. Currently, there is no internal screen shop in the Mid-Pacific (MP) Region. External sources are private firms that market, design, and build fish screens for Reclamation and our stakeholders, e.g. Intake Screens Inc, Sacramento, California.

K. Blakney
In the Umatilla Project, Oregon, Reclamation operates the McKay Creek Fish Barrier. This barrier is in need of replacement.

An effective NPB might provide an excellent alternative: cheaper to construct than the current barrier and easy to turn on and off--and therefore easy to evaluate and control. This NPB will have far less maintenance requirements than positive barrier counterparts. Thus, operation of this NPB would save money for as long as the NPB is in place.

T. Leonard
In the Yakima Project, Washington, heavy ice builds up on the Roza Canal Wasteway fish barrier in cold winters--causing it to malfunction.

The NPB could be installed and left in place year-round because of the design. Then, it could be operated only in the winter as needed. This would save costs in labor. There is an important fish screening capability in the Yakima Project. Reclamation operates a large and effective fish screen shop. This shop produces positive barrier screens but not NPBs.

M. Kondratieff, Need:
There are thousands of applications like this all over the Western United States.

M. Kondratieff is considering applications of an effective NPB in Colorado.

For Reclamation, we conservatively estimate the potential savings in the tens of thousands of dollars in new screen installations. We estimate, with an effective NPB, the potential savings in maintenance costs to be in the hundreds of thousands of dollars over the next 10 years. This will provide more than a 10/1 return ratio in benefits/costs for this research project.

Contributing Partners

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Research Products

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Last Updated: 6/22/20