Monday, June 15, 2015

Snowpack at zero percent of normal; record lows for stream flows

But our partners in drought response are restoring streams in midst of drought 

by Dan Partridge, communications manager, Water Resources Program 

It’s official: the snowpack in Washington state is gone.
Statewide, the average snowpack is zero percent of normal.  That’s right, you read that correctly – zero.
Although some snow remains at very high elevations -- and embedded in glaciers -- that isn’t counted in the calculation of total snowpack.  Compare zero percent of normal to some of the snowpack figures from this time in 2014:  105 percent of normal  on the Olympic Peninsula, 138 percent of normal in North Puget Sound, 113 percent of normal in the Lower Yakima and 175 percent of normal in the Spokane River Basin!

Early snowmelt leaves no runoff for rivers and streams    

Snowpack is the primary water supply for most of Washington’s rivers.  In a normal year, snow accumulates over the winter and then slowly melts in the spring and summer with the runoff feeding our rivers and streams.  This year, because of the lack of snowpack over the winter and higher-than-normal temperatures in late winter and spring, the early snowmelt means we will begin summer with nothing left to run off.
The zero snowpack is leading to equally concerning stream flow numbers:  84 percent of Washington’s rivers are flowing below normal levels; 66 percent of rivers are at flow levels typically experienced less than once a decade; and 27 percent of river flows are at all-time record lows.
Communities and irrigators pull water out of streams and rivers for water supplies, and fish rely on streams for habitat.  The flows we are seeing the first half of June are what we would usually expect to see in August.

An early success story in stream flow restoration 

Although stream flows are at risk, it is encouraging to know that federal and state agencies and irrigation districts are working together to relieve hardships from drought.
That happened last  week in Kittitas County when the Kittitas Reclamation District (KRD) came to the rescue of Manastash Creek.
KRD has turned on siphons and water gates in its canals that provide flows to Manastash Creek and five other upstream Yakima River tributaries.  Under an agreement with the U.S. Bureau of Reclamation, Ecology, the Yakama Nation and in consultation with the state Department of Fish & Wildlife, Yakima Project water is being routed through KRD canals on its way to downstream diverters and passed through these small creeks.  It then flows back to the same river it came from and it is available for diversions further down the Yakima River.  This is being done in a manner that has no impact on the total water supply and still improves flow, fish habitat and vegetation lining creek banks. 
Manastash Creek at Cove Road: On June 1, with depleted flow (left); and on June 11 with flow being restored.

Water in canals transferred into streams  

This action is part of a drought mitigation strategy developed by Reclamation, Ecology and the Yakama Nation to maintain stream health during a drought.  The strategy is being implemented this year because of improvements to KRD’s infrastructure made possible through the Yakima Basin Integrated Plan and Ecology’s drought program -- paid for in part with state funds -- that allow water in the canals to be transferred into streams and then returned to the Yakima River.  Back in the river, the water travels downstream to irrigation customers with no negative impact on their supplies from this rerouting.    
This water routing system is significantly improving flows in the Manastash.  The creek had declined to flows of only three or four cubic feet per second and was essentially dry where it crosses Cove Road. 
With a summer forecast of warmer-than-normal temperatures and less-than-normal rainfall, it’s likely we will see more streams in stress like Manastash Creek.  Some small streams may even go dry. But it’s good to know that our strategies to restore streams can be successful when we work together.         

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