From a press release –

Cascade Water Alliance is continuing to assess the condition of the White River Project in its first full year of operating Lake Tapps.

To do that, Cascade will be dewatering-clearing all the water out of-the flow line from the headworks to the twin pipe inlet structure east of Printz Basin late this summer and into the early fall. Cascade purchased Lake Tapps in December 2009 and dewatering will allow staff to examine the structures and facilities and determine what must be fixed.

In addition, Cascade will be modifying its fish screen facility to comply with regulatory criteria while operating lower flows than previously done. This has not been done in about seven years.

To accomplish the outage and still assure the lake will be at full pool throughout the summer, Cascade will, at the same time, be filling the lake to the upper range of the full pool as outlined in the agreement with the Lake Tapps homeowners. The lake will be filled to about 543 feet in early August, ensuring a full lake all summer. This means adding approximately another four inches of water to the lake. The lake level will then slowly lower over the following 10 weeks, staying within the agreed upon full recreational pool level.

The project will last about eight to 10 weeks beginning Aug. 23 and running into October so Cascade can address issues it finds in its assessment of the flow line.

Cascade Water Alliance is a non-profit corporation, comprised of the cities of Bellevue, Redmond, Kirkland, Issaquah, Tukwila, the Covington Water District and the Sammamish Plateau and Skyway Water and Sewer Districts to provide safe, clean and reliable water to its 370,000 residents and 22,000 businesses.