Out of Harm's Way

A modern-day device -- the fish screen -- is helping the chinook salmon live out its ancient propagation cycle in California rivers and streams.

It is a cycle that many have witnessed: a chinook's climactic run from the Pacific Ocean to spawn, and inevitably die, in the stream or fish hatchery where it began life years before. Experts fear too few survive and that at least one race of chinook faces extinction.

Fish hatcheries assist survival odds by artificually spawning thousands of fish, but it is the wild salmon whose dwindling populations most concern scientists and water users.

Risks to the chinook are many, including agricultural diversion pumps that suck fish into irrigated fields.

Private engineering firms and government agencies, including the Department of Water Resources, are developing new technologies and utilizing new funding sources to help water users install fish screens to keep salmon, and other fish, out of harm's way.

More Funds for Fish
Fish screens are usually physical barriers, although screens of sound, light, and electricity have also been tried. Fish screens are not new, but computer modeling and other technologies now make it possible to fine-tune their design to specific and often tricky hydrologic conditions.

Increased funding, largely stemming from the federal Central Valley Project Improvement Act of 1992 and the 1994 Bay-Delta Accord between state and federal agencies, has spurred the pace of screening projects.

Parties to the Bay-Delta Accord pledged to provide $180 million toward fish screening and other ecosystem restoration projects as part of the accord's Category III program. In 1996 California voters provided $60 million of that amount by passing Proposition 204, the source of more than $33 million for 36 projects that were announced by Governor Wilson in December 1997. Under the accord, urban water agencies are also providing funding.

The federal share of Category III funds will be provided by appropriations in 1998, 1999, and 2000. Section 3406 of the CVPIA established the Anadromous Fish Screen Program under which the federal government pays up to half the costs of some screening projects. Water diverters and the State of California typically split the remaining cost.

Older sources of screening funds include agreements under which DWR and the federal Bureau of Reclamation mitigate for fish lost at their Delta pumping plants near Tracy. DWR signed the Delta Pumping Plant Fish Protection Agreement, or “Four Pumps Agreement” with the Department of Fish and Game in 1986, and the Bureau signed a similar agreement, referred to as the “Tracy Fund,” in 1992.

The total number of dollars available for fish screening has not been determined, largely because individual project funding is contained in a variety of programs running over different periods of time whose specific expenditures are subject to modification. But funding has increased markedly.

Progress Under Way
“We were idling along on the Four Pumps and the federal pump mitigation funds,” said Dan B. Odenweller, Fish Screen and Fish Passage Coordinator for the DFG. “The CVPIA is what kicked things loose.”

Screening progress has been dramatic and millions of dollars are being spent on numerous fish screening projects in the Sacramento Valley, the Delta and elsewhere in California.

“Three years ago, no major water users on the Sacramento River other than the Glenn-Colusa Irrigation District, the Tehama-Colusa Canal Authority, and the Anderson-Cottonwood Irrigation District were screened,” said Jeff Jaraczeski, a Sacramento water issues attorney with the firm of Downey Brand Seymour & Rohwer, who until recently was Director of Member and Government Relations for the Northern California Water Association.

“Today,” Jaraczeski said, “at least 12 major water users who divert between 70 and 80 percent of the total developed (controlled and managed) agricultural water on the river are in some stage of fish screen development.”

Among Sacramento River diverters in addition to the GCID, Tehama-Colusa Canal Authority and Anderson-Cottonwood Irrigation District that have completed, are constructing or studying large fish screen projects are the Princeton-Cordova Glenn Irrigation District, Provident Irrigation District, M&T Chico Ranch, Pelger Mutual Water Company, Maxwell Irrigation District, Reclamation District 108 and Recalmation District 1004.

Jaraczeski said that government’s determination to restore California’s fisheries is shared by Sacramento Valley farmers, many of whom are taking the lead in screening agricultural diversions.

“The message here is that everybody is getting serious about fish screens,” said Dick Daniel, Assistant Director for Habitat Restoration at CALFED, the state federal agency implementing the

Bay-Delta Accord
More than 70 years of fish screening history has been logged by the Glenn Colusa Irrigation District at its Hamilton City Pumping Plant on an oxbow of the Sacramento River west of Chico. That history includes costly lessons in the tricks a stream can play to frustrate engineering efforts.

A flood washed out GCID’s first fish screen shortly after it was installed in 1920, and another flood in 1935 reduced the efficiency of the district’s second screen.

A massive complex of 40 rotating drum screens designed by the Department of Fish and Game was installed at the GCID pumps in 1972 at a cost of $2.6 million. Each of the 40 screens was 17 feet in diameter and weighed 7.5 tons, but their design performance was never realized because changing river conditions lowered the water surface elevation at the pumping plant. Flat-plate screens were installed in 1993 and the rotating drum screens were removed as the district and government agencies continued to seek a permanent solution to fish loss problems.

Today, computer and modeling technologies that were not available in 1920, 1935, 1972 or even 1993 are being tapped by GCID, consultants and state and federal experts to fence chinook salmon and other fish out of the approach waters to GCID’s pumps.

“We have more tools and experience now to predict hydraulic behavior of a large fish facility and really are a lot more confident in what we can expect,” said DWR Senior Engineer Darryl Hayes, who serves on the Technical Advisory Committee for the GCID project.

It became apparent that the Sacramento River’s hydraulic behavior had to be altered to prevent stream level changes from again reducing fish screen efficiency. The U.S. Army Corps of Engineers will stabilize the water level at the GCID site by constructing a gradient facility similar to a man-made riffle in the main stem of the river.

The new GCID flat plate screen (approximately 1,100 feet long) is expected to be the biggest of its type in the world, as was the district’s complex of rotating drums when dedicated in 1972. Construction of the new facility will begin in the summer of 1998.

As part of the CVPIA, Congress authorized the Bureau of Reclamation to pay 75 percent of the cost of the GCID screening project, estimated at $32 million including the screen and river gradient facility. GCID and the State of California each will pay 12.5 percent of the cost. The project is expected to be completed in the year 2000.

A Treadmill for Fish
Size, history and cost have focused attention on the Hamilton City Pumping Plant, but innovative fish screening projects dot the Central Valley and new ideas are being sought in the laboratory.
“We’re trying to figure out where the gaps are in our understanding,” said Hayes, who is also chief of the Fish Facilities Section in DWR’s Environmental Services Office.

One gap was dramatized when the state and federal governments listed the Delta smelt as threatened in 1993. “We don’t have good criteria for the Delta smelt, as to what will and will not work with fish screens,” said the DFG’s Odenweller. “Studies are being done at the University of California at Davis to find out.”

DWR’s Hayes is heading the UC Davis studies, using a circular flume dubbed the “Fish Treadmill” in which fish encounter realistic screen conditions that can readily be changed for experimental purposes.

Fish “treadmill” research will help determine the hydraulic conditions under which fish of different species and in different stages of physical development will be able to safely bypass screens, avoiding fatigue, impingement and entrainment.

“Much of the existing research has focused on salmonid species instead of the increasing numbers of fish which are in need of protection in California’s Central Valley,” Hayes wrote in a scientific paper. “With this need identified, a program is under way to address the screening needs for a number of California’s native fishes.”

The three-year treadmill study that began in the summer of 1997 is a joint enterprise of the Department of Water Resources, the University of California at Davis, the Department of Fish and Game, National Marine Fisheries Service, U.S. Fish and Wildlife Service and Bureau of Reclamation. The research project is paid for by the 29 agencies that receive water from the State Water Project under long-term contracts with DWR.

Rebound Hopes
Rebounding to healthy numbers will be an upstream struggle for some races of salmon and some other California fish, but they are getting human help.

Is the increased help arriving in time?

Paul Jensen, a fisheries biologist and former Deputy Director of the California Department of Fish and Game, is optimistic. Speaking of the winter-run chinook salmon, which has been listed by state and federal agencies as endangered, Jensen said:

“Anyone who has watched salmon populations in California or elsewhere along the Pacific Coast can vouch for the fact that the animals are amazingly resilient.”

“Given that built-in resilience,” Jensen added, “it’s not too late to bring those fish populations back to acceptable population levels. All we have to do is to commit ourselves to the job. And all of us seem increasingly willing to do that.

“Of course, all the fish screens in the world are going to accomplish nothing unless there’s water left in the system in which the fish can exist. So along with fish screens must come some reasonable effort to assure that adequate flows for migration and spawning remain.”
DWR and the Bureau of Reclamation -- complying with fishery restoration goals of the CVPIA and the Bay-Delta Accord -- have increased fresh water flows from upstream reservoirs through the
Delta with apparently positive results.

The estimated spawning run of winter-run salmon -- one of four races of chinook on the Sacramento River and its tributaries -- was down to 186 adults in 1994 but increased to 940 in 1996, according to the Department of Fish and Game. Officials of the federally sponsored San Francisco Estuary Project credited the population upswing to several years of heavy rains and runoff, increased releases of fresh water by DWR and the Bureau of Reclamation and an increase in funds for environmental programs.