All that rain ... and still at risk

The following article appeared in the March 19, 2006 edition of The Olympian.

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All that rain ... and still at risk

By John Dodge
The Olympian

A water supply problem in South Sound? You’ve got to be kidding.

After surviving 35 straight days of rain in December and January and a typical 50-plus inches of rain a year, the water-logged residents of the area might find it difficult to believe that South Sound ever could run out of water.

But upon closer examination, the water supply budget for Thurston County is more akin to a family living on credit cards than the one that won the state Lotto.

Here’s why water for people isn’t in endless supply:

South Sound relies on rainfall to replenish the groundwater supplies, which provide most of the water for the region’s residents and businesses.

That same rainfall feeds our rivers, streams and lakes either directly or indirectly by flowing as groundwater into the surface water. In effect, groundwater and surface water are the same resource.

“A lot of folks are in denial that the two are connected,” state Department of Ecology spokeswoman Sandy Howard said.

In any given year, a volume of water equal to 88 percent of what enters the groundwater system annually — about 588,000 acre-feet of water — flows out to Puget Sound from area rivers and streams, according to a U.S. Geological Survey study of Thurston County groundwater flow patterns.

In other words, the groundwater doesn’t remain in permanent storage in the ground for humans to use as they see fit. It also feeds rivers and streams and flows out of the system.

“Water-in is equal to the water-out,” said Matt Ely, a USGS hydrologist.

“There isn’t some secret pocket of water that can be used without having an impact,” added Clark Halvorson, water resource manager for the Nisqually Tribe.

Segments of streams and rivers throughout South Sound already lack enough water for healthy fish populations and good water quality. It has been illegal to pull additional water out of the Deschutes and Nisqually rivers since 1980.

Adequate water in streams is critical for the recovery of Puget Sound chinook and other salmon species listed on the federal Endangered Species Act list.

Anyone seeking a water right for groundwater in those two watersheds must first prove the well won’t reduce stream flows, among other tests.

“You can’t use all of the groundwater recharge because it also feeds the base flow of rivers and streams,” explained Tumwater-based hydrogeologist Linton Wildrick. “We need that base flow for fish and recreation. We don’t want dry stream beds three months out of the year.”

The Department of Ecology set in-stream flow levels for the Nisqually and Deschutes rivers more than 25 years ago. But they still aren’t met in the summer months, said Tom Loranger, an Ecology water resource regional manager.

In the Deschutes watershed, the Squaxin Island Tribe has called for any new water supplies to be offset by water conservation and water reuse.

“There’s already too much water missing from the Deschutes River,” said tribal policy analyst Jeff Dickison. “The basin is closed to new withdrawals.”

In the Nisqually watershed, home to the endangered Puget Sound chinook salmon, the tribe is also keeping a close eye on any plans by Olympia and Lacey to drill new municipal wells, unless they can do it in a way that doesn’t reduce stream flows, Halvorson said.

With the concerns over in-stream flows, the likelihood of developing major new water supplies in the Nisqually and Deschutes watersheds, with the possible exception of the McAllister Springs area, is iffy at best, said Bob Wubbena, vice president of HDR Engineering Inc., in Olympia, a firm specializing in water management.

Rainfall and demand

Another reason the water budget of South Sound is tight has to do with when it rains.

The region receives most of its rainfall in the winter months, when demand for water is lowest. It gets very little rainfall in the summer months, when demand by people and fish is the greatest, and groundwater is needed to maintain stream flows.

“And when it rains a lot, a lot of the water just runs off as stormwater runoff,” Ecology hydrogeologist Tammy Hall said.

With population growth and development come more hard, impervious surfaces that don’t allow the water to soak into the ground naturally.

State and local ordinances require stormwater to be corralled and infiltrated back into the ground through stormwater retention ponds, but there is plenty of room for improvement to keep stormwater runoff in the groundwater budget and out of Puget Sound, said Andy Haub.

Another limiting factor for groundwater use is toxic waste pollution.

Thurston County has been home to several hazardous waste sites where solvents, petroleum products or pesticides have traveled through the soil and into the drinking water supplies of several thousand people.

The most notable case occurred in the early 1990s in Tumwater, when industrial solvents were detected in wells serving the city’s water customers, triggering a Superfund cleanup and construction of a water treatment plant at the vulnerable Tumwater Valley wells.

But the threat of groundwater pollution remains, especially as the population continues to grow, with an estimated 150,000 more people by 2030.

“The more population we have, the harder it will be to protect the groundwater from pollution,” said Olympia resident Leslie Romer.