Saturday, November 21, 2009

ONGOING COVERAGE: SPOKANE RIVER RAFT & PADDLE EXPEDITION

A river's journey: A special report

Afloat over – and in – the aquifer

Learning about formation of water source a centerpiece of this leg of trip

Chris Hosmer looks at a picture she took of her husband Rick, right, and Andy Dunau on Saturday. The Spokesman-Review (J. Bart Rayniak The Spokesman-Review) Related information Read more

Becky Kramer
Staff writer
July 15, 2008

About 10,000 years ago, the Missoula Floods laid the bedrock for the region's water supply.

An ice sheet crept across the Idaho Panhandle, damming the Clark Fork River and creating glacial Lake Missoula, which extended 200 miles to the east. The ice dam failed repeatedly, sending water, ice and house-size boulders roaring through the Columbia Basin.

During particularly ferocious floods, the water moved at freeway speeds of 65 mph. But during the ice dam's waning years, the floodwaters slowed.

Gravel and cobbles sifted out. The porous glacial debris became the Spokane Valley-Rathdrum Prairie Aquifer – a source of drinking water for more than 500,000 people.

The aquifer was on our minds Saturday as we rafted about 15 miles of the Spokane River between Post Falls' Corbin Park and Plantes Ferry Park in Spokane Valley.

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"You're floating in your drinking water," said Guy Gregory, a supervisor in the Washington Department of Ecology's water resource program. He made the trip in an 8-foot yellow pontoon boat with a fishing rod attached to the back.

The river and the aquifer are really the same water body, said Gregory, who was the Washington manager of a $3.5 million bistate aquifer study. He took advantage of "teachable moments" on the water, even though it meant shouting back and forth among rafts.

Gregory's booming voice helped. "He's always the loudest guy in the group," another ecology department official said.

Between Stateline and the Sullivan Road bridge, the Spokane River feeds the aquifer, losing about half its flow to underground gravel. At Sullivan Road, however, swimmers start noticing cool pockets in the river.

That's where chilly water from the aquifer – about 49 degrees – percolates into the river, recharging its flows and providing cold water for a native redband trout population.

Last week, Spokane Mayor Mary Verner proposed reducing the summer demands on the aquifer by outlawing the use of sprinklers from noon to 6 p.m. from May through September. Violators could be fined $125.

It would be a bold move for a city that prizes its green lawns. But the days of super-lush landscaping and free-for-all watering may be coming to an end. Spokane County's per capita water consumption – 217 gallons per day – is about twice as high as the state average. The region needs to develop a water conservation ethic, local officials said.

The aquifer isn't running out of water, Gregory said. Water from lakes, streams and precipitation recharges it. But sucking water for human uses out of the aquifer is reducing river flows by about 225 cubic feet per second. That's roughly equal to the aquifer-recharge from precipitation.

"Nobody wants a dry river," Gregory said. "It's not good for the economy; it's not good for our way of life. With more people moving here, we need to take some steps toward conservation."

During Saturday's rafting trip, we enjoyed unseasonably high flows along a wide, meandering stretch of the river. Mergansers, a fish-eating duck, dived along the shoreline. The water was clear enough to see suckers nosing the river bottom.

The sloping hillsides were relatively bare of development. Several people on my raft noted the sharp contrast from the built-up Idaho shoreline above Post Falls Dam.

In Washington, houses are set farther back from the water. Stricter zoning laws – along with public land ownership – preserved a more natural-looking shoreline.

A diverse group of people was out using the river. We saw several other rafting parties, plenty of inner-tubers and a few fishermen.

Kayakers played in the rapids near Sullivan Road. Homeless men camped nearby.

A public beach near the Harvard Road bridge was also busy. The beach will close in late summer, while soils containing lead, arsenic and other heavy metals are removed or capped.

The metals, deposited over decades, came from upstream mining activity in Idaho's Silver Valley. The beach is one of nine areas on the Washington side of the Spokane River identified for cleanup.

The work will make the site safer for wildlife, as well as people, said Zach Hedgpeth, Ecology's coordinator on the project.

Trout spawn in the area. "They lay their eggs right in the contaminants," he said.