La Niña winter final roundup

Late winter precipitation boosts water supply for summer

Continued cold, snowy weather during late winter brought the good news we needed for this summer’s water supply. As we transition to more spring-like weather, Washington’s snowpack levels are near or above normal for this time of year.

Statewide snowpack

Across the state, the snow supply average is 119 percent of normal. That number is a big WOW for farmers, fish managers, and water users in cities and towns, as they breathe a sigh of relief.

Earlier water supply forecasts contemplated lean snow levels in the Walla Walla Basin, but heavy March snow improved the basin-wide snowpack to 111percent of normal. The lower Snake River snowpack is particularly flush at 124 percent of normal.

The lower Columbia region — consisting of the Cowlitz, Lewis, and Washougal watersheds — recovered to 108 percent of normal from 88 percent in late February. The upper and lower Yakima River Basin are at 101 and 103 percent of normal, respectively. The Olympic Mountains (119 percent of normal), north Puget Sound (124 percent of normal), upper Columbia basins (143 percent of normal) all have healthy snowpack.

As we begin both early spring and irrigation season, there is ample mountain snowpack and cool temperatures forecasted by the Climate Prediction Center for the immediate future.

One area of minor concern that the snowpack is nearing saturation point, and heavy precipitation may initiate faster melt off.

Although some spots were dry March 11-April 9, the Cascades and north central WA received ample precip

Precipitation

Precipitation at mountain SNOTEL sites since the beginning of the water year is 112 percent of normal. Puget Sound headwaters stations range from 105 percent of normal at Stampede Pass, to 140 percent of normal at Huckleberry Creek. Both the upper and lower Yakima basins are at 108 percent of normal for precipitation.

Statewide precipitation over the previous 30 days is slightly below normal in Western Washington, and average in Eastern Washington. The last seven days, however, have been near or above average for the state (including non-mountain areas).

The precipitation outlook for the near term is for above normal precipitation through spring.

The U.S. Drought Monitor indicates there is no data suggesting drought for portions of Yakima and Klickitat counties in south central Washington. Most states to the south of Washington are experiencing some drought, ranging from Abnormally Dry to Exceptional Drought in Oklahoma.

Temperature

Temperatures in Washington have been near-normal statewide, averaged over the previous 30 days. The Climate Prediction Center forecasts below normal temperatures for both the next two weeks and normal temperatures for the remainder of spring. Cooler temperatures aide the water supply outlook by regulating the rate snow melts and discharges into rivers. 

Yakima County was the only real hotspot for temps March 11 to April 9

Streamflows

Looking ahead to this summer, both the Natural Resources Conservation Service and National Weather Service are forecasting that we are likely to have normal to above-normal water supplies this year.

For water supply purposes, the April to September runoff period is critical because this is when water demand is highest, but precipitation is lowest, hence our scrutiny of snowpack and reservoir levels.

This year, forecasted runoff for this period is above 100 percent of normal in all but one or two locations. In fact, some locations in the Upper Columbia River Basin (e.g., Kettle, Okanogan, Methow Rivers) have forecasted runoff in excess of 125 percent of normal, which may portend flooding.

We’ll continue to keep tabs on streamflows through the spring and summer.

Irrigation and storage reservoirs

In the Yakima River Basin, the U.S. Bureau of Reclamation operates five reservoirs to store water for agriculture irrigation and fishery purposes. At this point, total system storage (all five reservoirs considered together) is 119 percent of average or about 818,000 acre feet. Total storage capacity is a little over one million acre feet. Reclamation forecasts that they will be able to meet 100 percent of water supply to users of project water this year. The bureau will update its forecast in early May

On the west side, the City of Seattle stores water on the Cedar and South Fork Tolt rivers. Snowpack is continuing to build and is above the long-term median for this time of the year. Snowpack in Seattle’s mountain watersheds typically reach peak accumulations around the first week of April. Storage is also above long term median conditions.


Beginning-of-month storage conditions for other reservoirs in Washington state are available at the NRCS interactive mapping tool. 

• Read more about statewide conditions. 
• Related blogs:
  La Niña winter update
Is this a typical La Nina year?

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.

Did you grab a jacket or sweater while celebrating the Fourth of July? The weather felt different from last year for lots of folks across the state. Our water supply situation is different, too.

In summer 2015, we were in the midst of a drought emergency. This winter, plenty of snow and rain helped reduce impacts from the drought, but a hot and dry spring concerned experts. Luckily, the recent run of normal-ish temperatures and precipitation have improved our statewide water supplies.

Status of our supplies

Here’s the latest on our water supply conditions as of July 6:

Weather impacts | Over the past two weeks, precipitation has been about normal statewide – within 1.5 inches of average. But the coast and northeast parts of the state, already dry from spring, have stayed on the below-average side.

Average statewide temperatures for the past 14 days have stayed within 0 to 4 degrees above normal. Water use is declining due to more moderate temperatures compared to last month. In Seattle, the city’s public utility reports that daily demand is down nearly 50 million gallons per day from last year.

This USGS map compares current (July 6) and historical stream flows in
Washington. Click here to see more.

Rivers and streams | Rivers are naturally at their lowest flows during summer, but our rivers are experiencing – and will continue to experience – the effect of drier-than-normal spring weather and rapid snowpack melt. Statewide, about 58 percent of rivers are below average. This is an improvement over the beginning of June, when 77 percent were below average. (This doesn’t mean river flows are getting higher. Rather, compared to the same time of year for the period of record, we are closer to average now than we were in early June.) Looking back, 79 percent of our rivers were below normal last year around this time.

 

Agriculture | The Bureau of Reclamation manages several large reservoirs in the Yakima River Basin, an important agricultural center, and releases forecasts of how much water farmers can expect from those reservoirs. Currently, the areas with junior water rights are expecting 86 percent. Last year, they were at 47 percent. Senior water right holders are expecting a full forecast.

Managers of sockeye salmon fisheries are closely watching water
temperatures. Photo: William Meyers/WDFW

Fish | River temperatures are on the rise, but we’re still better off than last year, when sockeye salmon and sturgeon mortalities were being reported. This year, enough sockeye have entered the Columbia River and migrated upstream from McNary Dam for the Washington Department of Fish and Wildlife to open sockeye fisheries. Due to the debilitating losses of almost all spawning sockeye in the Okanogan River in 2015, fisheries managers are proceeding conservatively until it’s confirmed enough spawning fish make it into the Wenatchee and Okanogan rivers. As the run progresses upriver, sockeye seasons above Priest Rapids Dam are likely as long as water temperatures stay cool. Anglers should visit WDFW's website for more information.  

Drinking water | Drinking water supplies are not currently projected to be affected by shortages. Contact your local municipal water system to learn more.

What’s next

Tomorrow, the Water Supply Availability Committee (WSAC) will hold its monthly meeting. This committee is a team of experts from state and national agencies who review data and discuss potential water shortages. If conditions warrant, this committee can convene the Executive Water Emergency Committee (EWEC), which is made of state agency leaders with a stake in water supplies. These leaders assess findings from WSAC and determine whether water users in affected areas will likely incur undue hardships. EWEC can recommend the governor consider an emergency drought declaration.

How you can help

Outdoor water use accounts for nearly a third of daily water use by U.S. households. You can conserve water – and save money – by making a few tweaks to your outdoor routine:

• Purchase an inexpensive hose timer to avoid over-watering. Soaker hoses are also a great option for avoiding evaporation.
• Use a broom or electric blower to clean driveways and sidewalks, rather than hosing them off.

For more tips, visit our water conservation page. 

By Kristin Johnson-Waggoner, Water Resources Program communications manager

Watching the water supply

As the recent cool-down gives way to warmer, drier summer weather, we are closely monitoring our water supplies. Last year, a lack of snowpack and spring rain led to a drought that had statewide impacts. This year, our water supplies are currently stronger across the state but we’re watching areas of concern.

There are two groups that keep close tabs on our state’s water supply. The Water Supply Availability Committee (WSAC) is a team of experts from state and national agencies who meet monthly to review data and discuss potential water shortages. If challenging conditions are identified or projected, they will bring the information to the Executive Water Emergency Committee (EWEC). This committee is made of state agency leaders with a stake in water supplies (Departments of Agriculture, Commerce, Health, Natural Resources, Ecology, Fish and Wildlife, etc.). These leaders assess findings from WSAC and determine whether water users within affected areas will likely incur undue hardships.

At its meeting in early June, EWEC did not issue an emergency drought recommendation to the governor, which they did in 2015. The group discussed areas of concern and will continue to monitor water supplies. They will meet again should conditions change.

To help keep you informed, we’ll be sharing regular water supply updates on this blog. (Click here to read an earlier post on this topic.)

Status of our supplies

Here’s a look at water supply conditions as of June 17:

Paradise on Mt. Rainier received a few inches of snow
this week (June 7 top; June 14 below), but most mountain
snowpack monitoring  stations are currently snow-free.
Photos: National Park  Service webcam

Weather impacts | Cooler, wetter weather helped improve river flows in on the west side of the state where spring rains were in short supply this year. Today, about 56 percent of stream gauges are at below-normal levels. A couple weeks ago, about 75 percent of our gauges were below normal. The eastern side of the state did not benefit as much from rain. Rivers fed by melting snow (the Methow, Wenatchee and Okanogan rivers, for example) were running high due to early melt but are now below normal. While snow fell at higher elevations this week, most of our snowpack monitoring stations are currently snow-free.

Agriculture | The U.S. Bureau of Reclamation manages several large reservoirs in the Yakima River Basin, an important agricultural center, to help farmers irrigate through the dry summer months. As of Saturday, the Bureau began releasing water – about a week earlier than average – from the reservoirs to downstream irrigators. Last year, this action began in mid-April. The Yakima reservoirs are fuller this year – at 98 percent capacity.

Drinking water | Drinking water supplies are in good shape and aren’t currently projected to be affected by shortages. Contact your local municipal water system for information specific to your community.

Cle Elum Lake is a reservoir managed by the U.S. Bureau 

of Reclamation.  

More information | Visit our Washington water supply information page to read about streamflow, snowpack, precipitation, forecasts and more. 

Focus on fish

Fishery populations across the state face challenges again this year. Low flows in some streams and rivers are stressing migrating juvenile salmon, and Washington Department of Fish and Wildlife hatchery teams are already responding to warm water conditions. Water temperatures in the Columbia River are higher than average, even exceeding 2015 temperatures on some days earlier this spring. WDFW staff remain on alert for low-flow fish migration blockages and high water temperatures as we move into July.

How you can help

Water is a shared resource and we all have a responsibility to protect it. Here are two easy water conservation tips you can use at home:

• About 30 percent of our water use across the state goes to outdoor watering. When planting your landscape, consider drought-tolerant native plants and check to see a plant’s watering needs before you schedule your sprinklers.

• You can significantly reduce water use by simply repairing leaks in fixtures (faucets and showerheads), pipes and toilets. A leaky faucet wastes gallons of water in a short period of time. A leaky toilet can waste 200 gallons per day. That would be like flushing your toilet more than 50 times for no reason!

Check out this page for more tips.

By Kristin Johnson-Waggoner, Water Resources Program communications manager