Why is this drought so wet?

Reasons why a lot of rain doesn't always mean the end of a drought

With higher than normal snowpack and one of the wettest springs in recent memory, there are people out there who’ve questioned why we recently extended a drought declaration for certain regions of the state.

According to state law, when water supply is above 75 percent of normal, that area doesn’t qualify for drought. May ranked as the 8th wettest May since 1895. That followed the 10th wettest April. Together, April through May ranked as the 4th wettest such period. All that water can lead many people to view a drought declaration with skepticism. Some people might even ask, given how wet things have been, what’s going on in these areas we’ve marked as “red” on our drought map?

WRIA 49 (Okanogan)

river surrounded by trees

The Okanogan watershed — or Water Resource Inventory Area (WRIA) 49 — is located in Northeastern Washington, covering a large portion of Okanogan County. The Okanogan River originates in British Columbia, flowing southward from Okanogan Lake and then Lake Osoyoos at it crosses the international border. Its largest tributary, the Similkameen River, also originating in Canada, enters shortly downstream. The watershed includes various tributary streams such as Antoine, Bonaparte, Chewiliken, Siwash, Tonasket, and Tunk creeks and Salmon Creek.

The April-September seasonal volume forecast for the Okanogan River at Oroville is currently at 64 percent of normal, which is below the state’s statutory threshold for drought. Below the confluence with the Similkameen, the picture improves considerably with seasonal runoff substantially forecasted above the state drought threshold. The primary water supply concern in the Okanogan watershed is with the small tributaries that originate in the lower elevation areas in the watershed. Along Salmon Creek, for example, the Okanogan Irrigation District stores water in Concunully and Salmon Lakes. Those reservoirs failed to refill over the winter months. Storage there is below 50 percent of normal. The district will need to conserve water carefully this summer and will likely have to resort to a backup pump on the Okanogan River, which brings with it significant energy costs.

WRIA 43 (Upper Crab/Wilson)

Desert landscape with green brush in the foreground

The good news here is there probably won’t be many curtailments, as most agriculture here is of the “dryland” variety, meaning agricultural production is heavily dependent on soil moisture as opposed to irrigation. According to local conservation district staff, many ponds and springs are still dry. A USGS monitoring well near Davenport indicates that shallow groundwater is below the 10th percentile of historic measurements, placing the area well below the 75 percent threshold for drought. This suggests that the area has yet to fully recover from the dry conditions experienced over the last  several years. October through May precipitation came in about 93 percent of normal for the watershed — which is not enough to erase long-term precipitation deficits.

There is potential hardship for dryland farmers and livestock owners looking for places to water their animals.  

WRIA 55 (Little Spokane)

river surrounded by trees

The Little Spokane watershed — or Water Resource Inventory Area (WRIA) 55 — is defined as the area that drains to the Little Spokane River, which in turn flows to the lower Spokane River. It is located in Eastern Washington in upper Spokane County, lower Pend Oreille County, and a small portion of Stevens County.

The Little Spokane River’s major tributaries are the West Branch Little Spokane, Dragoon, and Deadman creeks. The watershed includes various other tributary streams such as Bear, Buck, Deer, Dry, Little Deep, and Otter creeks.

This area is doing a little better than models were forecasting a few weeks ago, with forecasted seasonal runoff at about 78 percent of normal, placing it just over the threshold for drought. Curtailment of water users junior to the Little Spokane River Instream Flow Rule is still possible. It’s important to remember that a forecast can adjust up as well as down, so it might be a while before we officially end the drought in this area.

WRIA 56 (Hangman)

river surrounded by trees

Hangman Creek watershed begins in the foothills of Northern Idaho and spans across the southeastern portion of Spokane County. Like Little Spokane, this watershed is home to dryland agriculture but also includes some irrigation use. Recent forecasts for Hangman have surged from much below normal to above normal (104 percent). If that forecast holds, Hangman Creek may be safely out of drought status for the coming summer.

WRIA 59 (Colville)

Farm surrounded by trees

The Colville River watershed spans about 1,300 square miles and is located primarily in Stevens County. The watershed extends from the towns of Springdale and Loon Lake to the town of Kettle Falls at the northwestern extent of the basin. The Colville River’s headwaters include Sheep Creek and Deer Creek at the southern end of the basin. Forecasts for this watershed predict about 70 percent of the normal water supply, but conditions are improving. Current forecasts suggest a low likelihood that flows will drop below the state instream flow rule for the Colville Basin.

Keeping up with conditions

Our statewide conditions page provides monthly updates on precipitation and weather conditions throughout Washington. Further water supply information is available on our water supply monitoring page.