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Young Fish Tested on Improved Turbines

by Mike Lee
Tri-City Herald, November 21, 1999

BONNEVILLE DAM - Rube Goldberg couldn't have done it with more style.

For sheer entertainment and complexity, the latest fish-saving machinations at the westernmost end of the Columbia River hydropower system are hard to beat.

They rely on Franken-fish, strangely modified chinook that are the forerunners, perhaps, of better things to come for millions of Columbia salmon.

Their purpose is to test a new breed of turbines that will still transfer the power of falling water into cheap electricity while harming far fewer ocean-bound fish.

The so-called minimum-gap runners have been in development for years, but Bonneville Dam is the first in the Columbia-Snake system to be retrofitted, and the Corps of Engineers is planning to install one of the new turbines each year until 2007, if Congress allocates the millions of dollars necessary.

The new engines, also known as Kaplan turbines, promise to substantially reduce fish kills.

"The model ... did just fine (in the laboratory)," said Debby Chenoweth, Corps official at Bonneville Dam. But "you can only get so close with models. ... Now we need to see the real thing."

That real-life look started Monday with the first in-river tests of the highly touted turbines, called "minimum-gap runners" because they reduce the area where fish can get trapped, injured or killed.

For Normandeau Associates, the East Coast company hired to test the fish compatibility of the new engines, the experiment is like playing a complicated game of catch. The only thing that stands in its way is the giant wall of concrete built in the 1930s.

On the upriver side of the dam, one 6-inch-long silver chinook at a time is anesthetized and Enn Kotkas marks its critical measurements on a computerized note pad.

The fish are already missing a fin, which was clipped to show they are not wild. The science team takes off one more side fin to note which turbine the fish will go through.

Paul Heisey, project manager for Normandeau, then staples a short pin through the fish's dorsal fin. Attached is a small, deflated yellow balloon and a radio transmitter the size of a Gummi Bear with a 6-inch antenna.

A second balloon is secured near the tail just in case the first one fails. And a sliver-sized gold plastic marker with a barely readable code number is inserted under the skin near the gills.

The groggy fish recover in green plastic tubs, artificial appendages bobbing like tiny boxing gloves from their backs.

Within a few minutes, the fish is carted to a plywood shed where Will Twupack and George Nardacci listen to the two-way radio for the go-ahead signal.

Their work area is a pool of swirling water, perhaps 4 feet deep and reminiscent of an ever-running toilet tank. The water is draining through one of three PVC pipes that lead to the spinning turbine blades deep inside the dam.

Downriver from the dam, chase boats with antennas as long as their hulls patrol the exits. On their command, Nardacci injects a drop of warm water into each balloon while the fish rests in Twupack's hand.

Then Twupack slips the fish into a PVC pipe, the pinging of its radio transmitter audible on the radio scanner. It's gone in a flash, traveling the water slide at 12 to 15 feet per second into the bowels of the machine. One pipe puts fish on the inside edge of the blades, another hits the middle and the third aims at the outside edge.

The blade edges are the key spots for the experiment - that's where these new multimillion-dollar turbines are supposed to decrease fish injury.

Fifteen or 20 seconds after disappearing, the chinook rushes into the Columbia River, with an unobstructed path to the ocean. But it won't get far. During its speedy tour, warm water injected into the balloons started eating away at gel caps inside the latex.

One cap releases an acid. Another releases a base. Together, they produce a gas - like dropping Alka Seltzer in water - which inflates the balloons to about the size of a ping pong ball and draws fish toward the surface. All the while, the boat patrol's antennas spin in search of the fish's radio signal, which reaches a half-mile when the fish is close the surface.

Once the fish is nabbed, Twupack and Nardacci get a call on the radio and the game begins again.

In the next two months, more than 7,000 fish will be subjected to the $2.5 million experiment at the rate of 120 a day. Once they've had their turn, the fish are rested for two days in a holding pond and then released to the ocean without their abnormal appendages.

By far, the majority will become food for pikeminnows, terns or anglers - but the legacy of the sacrificial fish of the Columbia River will live on. "It's a champion if it's gone through a unit," said Dennis Schwartz, Corps fish biologist.

In general terms, the problem with the turbines is not chopping up fish like a blender. Rather, fish get disoriented or killed in the gap between the turbine blades and the turbine core, or the gap between the blade and the outer casing.

Current estimates of fish survival through the turbines are from 89 to 94 percent, the Corps said, noting the new Kaplans may reduce mortality by 4 percent.

But Kaplans are more than just a fish-friendly gadget. The Corps said increased efficiencies mean each new turbine will produce enough additional power for about 15,000 homes in an average year.

If they are as good as hoped, new turbines could be on the way for other dams, where federal agencies and public utility districts are hoping to gain additional safeguards for federally protected fish.

Multiplied over eight federal dams on the lower Columbia and lower Snake rivers, even a 1-percent increase in fish survival "would be a significant benefit" to salmon stocks, the Corps said.

Mike Lee
Young Fish Tested on Improved Turbines
Tri-City Herald, November 21, 1999

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