Thursday, September 1, 2016

Watching the water supply

This blog post is part of an ongoing series about water supply conditions. Please click here to read the previous post. If you want to learn more, visit our Washington water supply information page.

Have we seen the last of summer’s high temperatures? The arrival of more moderate weather may feel like fall for many of us across the state. As we begin to transition into the next season, let’s check in on our statewide water supply conditions.

Status of our supplies

Weather impacts | Cooler and wetter weather is on the way. Over the next 10 days, Washington will receive much-needed rain. While the amount may be modest, it will help our rivers and streams rebuild to higher levels while lowering water temperatures.

The Walla Walla River in southeast Washington ran low in
Rivers and streams | This is the time of year when rivers and streams are at their lowest levels. The snowpack is long gone and rain has been infrequent, so rivers and streams are relying on groundwater. Currently, about 48 percent of our streams and rivers are at below-average levels compared to historical flows. Most of these are in the western half the state, though southeast Washington also has a number of low rivers. These dry areas have gone without their usual share of precipitation since early spring.

Last year, we experienced a record-setting drought that resulted in 70 to 80 percent of our rivers being below-average for most of the summer. But in mid- and late August, the weather turned cooler and thunderstorms rolled across the state, dropping the percent of rivers flowing at below-average conditions to 40 percent. Compared to last summer at the end of August, our rivers are actually faring worse because we haven’t had those big storms yet.

Agriculture | Most of Washington’s agricultural areas experienced a dry and hot August. Crops are doing well for the most part, but farm ponds and reservoirs are getting low. The large federal reservoirs used for irrigation in the Yakima River Basin are at about normal levels, which is good for farms and fish. Farmers in the Yakima region holding junior water rights are receiving 94 percent of a full water supply. Senior users have 100 percent.

Bull trout in Bumping Lake, a reservoir in Yakima County,
are heading up tributaries to spawn. Photo: WDFW
Fish | Low flow levels in rivers and streams can be tough for fish, but cooler overnight temperatures are helping. In the Puget Sound area, streams are averaging 1 to 3 degrees Celsius cooler than in 2015. To the north, the South Fork Nooksack River is about the same temperature as last year. The Chehalis River and nearby southwest Washington streams are running very low compared to normal. Good news can be found in the Upper Yakima and Naches river basins, where bull trout have started moving out of Bumping Lake and into streams to spawn. That’s encouraging after what happened last summer, when low lake levels prevented the fish from moving into Deep Creek, an important bull trout stronghold.

The Washington Department of Fish and Wildlife continues to watch for recreational rock dams that might impede upstream adult salmon passage.

Drinking water | Drinking water supplies are doing well. Seattle, Everett and Tacoma report normal or above-average water supplies.

How you can help

We all have a role to play in conserving water. Here are two ways you can make a difference:

  • When washing your hands, turn off the water while you lather up.
  • Don’t use your toilet as a wastebasket. Even better, use a leak-free, high-efficiency toilet. Toilets are by far the main source of water use in our homes – they account for nearly 30 percent of residential indoor water consumption.

For more tips, visit our water conservation page.

By Kristin Johnson-Waggoner, Water Resources Program communications manager

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