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Department of Ecology Press Release - October 11, 2005
05-253
SPOKANE - Flows in the Spokane River near downtown ebbed badly but were not the lowest on record during the "water year" that ended Sept. 30.
Cool, wet spring weather countered dire drought predictions for the Spokane area. Less lucky were other areas in Eastern Washington, such as Columbia, Lincoln, Garfield, Walla Walla and Whitman counties, which did suffer drought-related problems.
Water-resource experts at the Department of Ecology (Ecology) say the seven consecutive days of readings marked the seventh lowest seven-day flow since the Spokane water flow gauge was installed in 1891.
A "water year" is a term used by water managers, weather forecasters and climatologists. The current water year started Oct. 1, and ends Sept. 30, 2006.
Six of the seven lowest years on record for the Spokane River have come since 1988. The river dropped to 601-cubic feet per second (cfs) this year at the downtown gauge. In 2003 and in 1994, the flows were even lower, at approximately 500 cfs.
About 7.5 gallons are in a single cubic foot of flowing water.
The recent low flows boosted research by Ecology, the Idaho Department of Water Resources and the U.S. Geological Survey to better assess the amount of water in the aquifer and how the aquifer interacts with the river.
"The low flows this year helped us to get some good data on how the river and aquifer feed each other during low years," said Guy Gregory, Ecology's study manager.
The downtown gauge is the oldest continuous-operating flow-measuring device on any Washington river, according to Ecology water resource manager Keith Stoffel.
"We know more about flows in the Spokane River than in any other river in the state," Stoffel said. "While 600 cfs is a bad year, it fortunately wasn't as big a problem as the first part of the water year indicated it might be."
Gov. Christine Gregoire declared a statewide drought emergency on March 10 due to warm, dry winter weather that limited the accumulation of the state's normal mountain snow pack and caused what did accumulate to melt much earlier than normal. The drought declaration expires Dec. 31.
"If you look at the long-term trends, the river has significantly declined over the past 100 years, but the rate of decline has slowed down in recent decades," Ecology senior hydrogeologist John Covert said. "Over the decades, water use in the watershed has changed. Instead of growing crops, we're growing subdivisions."
Covert points out that in addition to increases in water use and changing use patterns, other factors contributed to differences in the level of the river from year to year. Those factors include historical differences in the level of Lake Coeur d'Alene and changes in the way the Post Falls Dam is operated, sending different amounts of water down the river at different times of the year.
The volume of the water in the Rathdrum-Spokane aquifer is more stable than the river, Covert said.
"The river and the aquifer are interconnected, with large volumes of water moving back and forth between the aquifer and the river," he said. "We have seen the declines in the summertime river flows and haven't yet identified significant declines in the aquifer.
"The river is the canary in the mine shaft."
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Contact: Jani Gilbert, public information manager, 509-329-3495, pager, 509-622-3073
Graph showing gradual decline in Spokane River levels over the past 100 years: http://www.ecy.wa.gov/programs/wr/drought/2005/spok7day.pdf
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