Tuesday, February 10, 2015

Formula for drought: Warm winters with rain, little snow

By Dan Partridge, Water Resources program communications manager 

For the second February in a row, we are closely watching winter water supplies in Washington  with our Water Supply Availability Committee (WSAC) partners.  

Comprised of state and federal agency representatives, WSAC monitors water supplies in Washington and decides if and when a drought declaration recommendation should be made to the governor.   
Snowmobile sits on bare ground near the Lost  Horse 
snowpack monitoring site southwest of Yakima. 
Like this time last year, Washington is experiencing a warm winter with little snow accumulating in the mountains.
In many parts of the state precipitation has been in the form of rain. The absence of snow accumulations, called snowpack,  sets up conditions that could result in a shortage of water later this year.

Snowpack numbers spell competition for water supplies

Earlier this month, the Natural Resources Conservation Service (NRCS) told the WSAC meeting that Washington’s snowpack statewide was only 39 percent of average. That could spell drought conditions and competition for water for our state’s many farmers and irrigators.

The Seattle Times this week reported snow levels at Washington ski areas at “possibly the lowest since the state began keeping annual counts 66 years ago.” For example, Snoqualmie Pass as of Feb. 8 had received 74 inches of snow this season, compared to a record annual snowfall of 191 inches during the 1976-77 season.
Snowpack serves as an important water resource in the state’s mountain ranges. Like a frozen reservoir, snow melt feeds reservoirs, rivers and streams and is delivered to farmers, irrigators and communities along the Olympic, Cascade and Snake River ranges.

Snowpack forecast not encouraging

NRCS  says the state needs to receive well over 200 percent of average snowfall between now and April 1 to catch up to normal snowpack accumulations.
Weather forecasts into March call for warm weather, more rain and less snow.  To be ready in case a drought declaration is necessary, Ecology is requesting drought relief funds from the Legislature. These funds in the form of grants can be used to drill emergency water wells, deepen existing wells for cities, farms or fish hatcheries or to pay for construction of pumps and pipelines.
By law, two conditions must be met before a drought can be declared in Washington state and funds released:
  • An area has to be experiencing or projected to experience a water supply that is 75 percent of normal, and
  • Water users in that area will likely incur undue hardships as a result of the shortage.

While lack of snowpack is a cause of concern, it is just one factor in the drought equation.
Rain, stream and river flows also factor into our water supplies. For farmers, how much water is available in our reservoirs can determine the success of the upcoming irrigation season. 

The seven-day average streamflow statewide was normal the first of February, although below normal in northwestern Olympic Peninsula. Snowpack was only 40 percent of average in the Yakima Basin, but storage in Bureau of Reclamation reservoirs in the basin was 167 percent of average.

Preparing to help if drought comes

Under these circumstances, no one is recommending a drought declaration but Ecology will be prepared to help in case it comes. WSAC also recognizes how quickly things can change. Last year, heavy snows in the second half of February increased the snowpack in river basins from as low as 35 percent to more than 70 percent of average. 
We may get by this year, but another year of low snowpack could mean less water carried over in reservoirs and spell drought next year.
For links to water supply information provided by all WSAC members, go to Ecology’s Drought Information Web page.

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