Thursday, June 18, 2015

A perfect storm on the White River

By Chase Gallagher, Southwest Region Communications Manager

Last winter, Lake Tapps in Pierce County was drained for maintenance crews to conduct extensive work on the Lake Tapps reservoir dikes and to replace the wooden flume. This meant taking the lake down to near historic low levels, leaving what looked like a galactic landscape with stumps sticking out of the ground and normally floating docks stuck on shore.

Lake Tapps during the low draw down of 2014

Normally, the snowpack melts, keeping the rivers going strong throughout spring and summer. The White River would flow and Cascade Water Alliance, the owners of the Lake Tapps reservoir, could divert their allotted water and the lake would begin to refill as it normally does each spring.  But this year, with our lack of snowpack, instead of melting snow we have our first statewide drought since 2005.

It was a bit of a perfect storm – normal maintenance meeting abnormal snowpack – that left Lake Tapps drained for the last few months. With decreased flow, the threshold for Cascade Water Alliance to be able to divert water into Lake Tapps couldn’t be met.

But as it turns out, there’s another perfect storm that’s leading toward the lake being filled.

Fish Apron under repairs in the White River

The Army Corps of Engineers needed to perform repairs on a fish apron a few weeks ago, which required holding more water up at Mud Mountain Dam. When that reserved water gets released, it temporarily increases the flow of the river. Think of holding a vessel under a running faucet, which reduces the water into the drain, and then pouring the vessel along the normal flow:

That extra flow was enough to meet the threshold, and Cascade Water Alliance could test their new concrete flume, and in turn begin filling the lake. We went to Buckley last week to see the diversion in action:

That little uptick on the right side of the chart shows water returning to Lake Tapps.

The circumstances for the extended drawdown of Lake Tapps are unlikely to happen again, and the same goes for the recent news in being able to begin the refill. But within these perfect storms, the story of Lake Tapps is one of cooperation.

The partnerships between Ecology, Cascade Water Alliance, the Muckleshoot and Puyallup Tribes and the Army Corps of Engineers all led to working together - finding a solution to keep the river flowing, ensure fish passage, and get Lake Tapps back to its picturesque self.

A slightly more full Lake Tapps on the right.

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