The Life Cycle: Hatchery project enhances fish, saves water

By Christine Pratt
Wenatchee World

WENATCHEE — A pilot project under way at the Eastbank Fish Hatchery is conserving huge amounts of water and could one day revolutionize the way salmon are raised to offset the numbers of fish killed while navigating the Columbia River’s hydroelectric dams.

Joe Miller, hatchery program manager for the Chelan County PUD, says a “water reuse” system in place at Eastbank uses nearly 90 percent less water than the traditional, rectangular concrete raceways that have been the industry standard for decades.

That’s important, especially considering that not everyone who depends on that water has fins and a tail.

The PUD-owned hatchery, near Lincoln Rock State Park in Douglas County, draws from the Eastbank Aquifer, the same Columbia River-fed water source that supplies the greater Wenatchee area and surrounding communities — about 67,800 people, plus farms and industry.

The Eastbank Hatchery accounts for approximately 70 percent of the aquifer’s total draw.

Local and regional experts say that efforts to conserve at the hatchery will prolong the region’s right to draw from the aquifer and postpone the estimated $25 million investment to develop an alternative drinking-water source.

“The question is whether the aquifer can handle the draw for everyone,” said Greg Brizendine, manager of the East Wenatchee Water District. “We believe it does have the capacity… but how do we coordinate our needs for the community with what the PUD needs for the hatchery?”

The Chelan PUD, the city of Wenatchee and the East Wenatchee Water District jointly operate the metro area’s “Regional Water Supply,” fueled by the Eastbank Aquifer.

The most recent estimates show that the region’s water right to draw from the aquifer could be depleted by 2025, based on an estimated population growth of 1 percent per year.

That’s a big improvement over the gloomy outlook just three years ago.

Riding a crest of home construction, subdivision and 206er-fueled population growth, experts in 2007 predicted that the region’s water right could be exhausted as early as this year.

The estimates coincided with Chelan PUD studies that suggested that the Eastbank Aquifer had warmed by 4 degrees since the 1990s — a sure sign, analysts then suspected, that draw was exceeding the aquifer’s ability to replenish itself.

The PUD began to explore alternate locations for the hatchery and ways to conserve.

Enter the water reuse pilot project.

Through its research, PUD officials hooked up with the nonprofit Conservation Fund’s Freshwater Institute, a West Virginia-based research-and-development program dedicated to sustainable water use.

The institute had been studying water reuse for some 20 years and working with the U.S. Department of Agriculture to conserve water, raise healthy fish and control wastes of aquaculture — farm-raised fish for human consumption.

In 2008, the PUD launched an experiment at the Eastbank hatchery to see if the efficiencies in water use and waste handling perfected by the aquaculture industry could be used for raising salmon for release into the wild.

The next year, it added a similar system for steelhead at its rearing facility below Lake Wenatchee near the union of the Wenatchee and Chiwawa rivers.

Aside from a project in Alaska to raise salmon for recreational fishing, the PUD’s pilot projects at Eastbank and Chiwawa are the first of their kind in the country and the only ones used to offset the dams’ impact on fish.

At Eastbank, a facility managed for the PUD by the state Department of Fish and Wildlife, the $750,000 aquaculture-style water reuse system uses two circular fiberglass tanks through which water is constantly flowing in a gentle, circular current.

PUD biologists added a bunch of summer chinook babies and hoped for the best.

About 75 percent of the water used is filtered, reoxygenated, mixed with 25 percent fresh water from the aquifer and reintroduced into the tanks.

The system allows fish droppings and uneaten food to collect over a central drain at the center of the tanks’ concave bottoms and be removed with a quick flush before they break down to dirty the water.

It’s an improvement over traditional, relatively flat-bottomed raceways which need to be tediously vacuumed.

The more static nature of raceway water causes the young salmon to group in the pockets where water temperature and oxygen levels are the best.

The round tanks’ circular flow eliminates that by creating consistent water temperature and oxygen levels.

The system allows more fish to be raised in the same amount of water for overall water savings of nearly 90 percent, Miller said.

As a surprise side effect, the system also appears to be rearing “fitter,” healthier fish that are more eager to migrate to the ocean.

The round tanks serve as “fish treadmills.” Their circular flow keeps the babies constantly swimming against the current in water that is more waste free and of a consistent quality throughout the tank.

Miller says the 25,000 steelhead smolts from the Chiwawa facility migrated nearly a week earlier than raceway-reared smolts, and their survival rate past McNary Dam, 200 miles and four dams downstream, increased from 51 percent to 80 percent.

“This is really a paradigm shift in the Northwest,” Miller said of the reuse-for-release system. “No one else in the West is doing this.”

The region’s water administrators are also encouraged.

Eastbank’s enormous draw from the aquifer differs from city and irrigation use, because it’s not considered “consumptive.”

The water it draws washes through the hatchery raceways and then heads back into the Columbia.

But a reduced water draw has benefits for everyone, says Steve King, director of Public Works engineering for the city of Wenatchee and the Regional Water Supply’s head coordinator.

“Any ability the PUD has to reduce consumption helps with the potential issue of warming water,” King says. “And it could allow pumping more water out of the aquifer during certain times of the year.”

The relative longevity of the regional water right can also be extended, King said, through local efforts like the city of Wenatchee’s to use reclaimed water from its treatment plant for park irrigation.

“The cost of building another source … is tremendous,” he said. “We have time to do adequate planning and more conservation. It’s not critical in nature, but it’s not something you want to forget about either.”

The East Wenatchee Water District’s Brizendine says the agencies’ efforts will help prolong a water supply that is ready-to-use right out of the ground, with no need for treatment.

“We agreed to give the PUD time for water reuse, and it’s been successful,” he said. “That’s awesome for those of us who live here and want to drink that water, because it’s just an awesome supply.”