Watching the water supply:

Southwest Washington bearing brunt of dry conditions

Although we don't expect much rain this time of year, one area of the state stands out for being drier than usual: Southwest Washington and most of the Olympic Peninsula.

The July 19, 2018, U.S. Drought Monitor map classifies

southwest Washington as having moderate drought-like

conditions. Much of the rest of the state is considered

abnormally dry.

The U.S. Drought Monitor map, one of the tools we use to assess state water supply conditions, classifies much of the region as experiencing moderate drought-like conditions. The map is updated weekly and available on our statewide water supply conditions webpage.

Streamflow data also point to low flows in the region.

We’re seeing many rivers and streams in southwest Washington run at record low levels. The Chehalis River near Grand Mound is running at 113 cubic feet per second—a flow level in the 1st percentile, meaning flows are so low they are exceeded 99 percent of the time for this time of year historically. The Willapa River near Willapa is at 20 cubic feet per second, which is in the 1.5 percentile, meaning the flow is exceeded 98.5 percent of the time for this time of year historically. Irrigators, fish and aquatic habitat are most affected by these low flows.

Citing low flows in the Cowlitz River, the city of Kelso has asked its residents to take  

The Chehalis River winds its way west of Chehalis (July 19, 2018). We're
seeing record low flows on parts of the river. 

voluntarily water conservation measures until water levels in the municipality’s water source improve. To the north, the city of Forks and two small Jefferson County water systems are also asking their customers to follow voluntary conservation measures.

NOAA’s climate prediction center is predicting warm, dry conditions for the rest of summer. We are closely monitoring water supply conditions and working with other state agencies to track impacts. If you’d like more detail, read our water supply webpage.

Are we in a drought emergency?

Under Washington State law, emergency drought conditions are identified when water supply in an area has or is predicted to have 75 percent of normal water supplies AND undue hardships expected as a result. 

Drought emergencies are declared using a formal process based on statute. At this time, we have not declared a drought emergency anywhere in the state.

A rain-fed water system

The hydrogeology of southwest Washington is unique. Water supplies rely heavily on rain and less on snowpack from the Cascade and Olympic mountains. This means the region’s water supplies are more sensitive to above-average temperatures and below-average precipitation like we’ve been experiencing.

The effects of the unseasonably warm and dry weather in May led us to issue water use curtailment notices. We asked 88 junior water right holders—mostly irrigators—in the Chehalis River basin to stop using river water until flows increase.  This is the fourth consecutive year we have issued curtailment orders or notices for junior surface water irrigation uses in the basin. It was also among the earliest dates we have curtailed this group of water users.

Office of Chehalis Basin

In 2016, the Legislature created the Office of Chehalis Basin within Ecology. While a main focus of the new office is to pursue long-term flood-damage reduction and restore aquatic habitat in the state’s second-largest river drainage system, the Office of Chehalis Basin is also tracking the impacts of the dry conditions.

By Kristin Johnson-Waggoner, communications manager

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

Taking the Temperature of the Pilchuck River

By Ralph Svrjcek, Water Quality Program, and Nuri Mathieu, Environmental Assessment Program

Ecology's Ralph Svrjcek uses a datasonde to measure
water conditions in the Pilchuck River, July 2014.

The Pilchuck River is an important resource for people and fish.  In summer, hundreds of local residents cool off in its waters during hot weather. Needless to say, fish need to stay cool during the heat, too, in fact they require cold water to survive.   

Salmon need summer water temperatures no higher than about 62 degrees, Fahrenheit.  However, limited data collected by Ecology, Snohomish County, and others show the Pilchuck’s water can reach the mid-70s.  Ecology's Environmental Assessment Program and Water Quality Program are teaming up to gain a better understanding of Pilchuck River temperatures as part of the French Creek/Pilchuck River Temperature and Dissolved Oxygen Total Maximum Daily Load (TMDL) Study.

What we're doing

We’re measuring river temperatures and water levels three different times this summer.

It’s called a synoptic survey. We first did this in early July when the sun was high and river levels started to drop. We’re taking our second survey this week after a long period of warm and dry weather, and as river flows continue to drop.

We measure water temperature, conductivity, and dissolved oxygen at more than a dozen key river locations.  This shows us where cooling and warming processes are occurring. We hope to identify the most important areas of the river for fish.

Who else is on the team?

Ecology is getting help in the field this summer from the Tulalip Tribes and Snohomish Conservation District. We also received good advice and guidance from the fisheries scientists at Snohomish County’s Surface Water Management Division to help us make our 2014 field work as useful and productive as possible.

What’s next?

The data we collect will be incorporated into our study to improve water quality in the river, called a TMDL. In early 2015, we will convene an advisory group

This long probe gathers continuous profile of the river’s
temperature as the team floats down the Pilchuck River.

that includes staff from the Tulalip Tribes, Snohomish County, French Slough Flood Control District and others to review our results and determine what actions are needed to reduce the high temperatures in French Creek (sampled in 2012) and the Pilchuck River. After that work is completed we will hold a public meeting and make the draft study and recommendations available to the general public for review and comment.