The myth of a watershed solution to cleaning up Capitol Lake

Proponents of keeping Capitol Lake say that if we only cleaned up the entire Deschutes River watershed, water quality problems in the dammed estuary would go away.

From the Save Capitol Lake website:

Broaden focus to watershed for improved water quality: The CLIPA findings support more effective management of the upper Deschutes Watershed to address water quality issues including: dissolved oxygen, temperature, nutrient loading, sediment control, and removal of point discharges of other contaminants.

Actually, water quality problems such as dissolved oxygen, temperature, nutrients and sediment are inherent to the lake itself and aren’t caused by an up-river problem.

John Konovsky, environmental program manager for the Squaxin Island Tribe recently gave a presentation on how little watershed actions can do for the health of Capitol Lake:

We totally agree with CLIPA that a watershed approach is essential the maximum water quality benefit to the whole system. Where we kind of disagree is that a watershed approach is not sufficient to clean up the lake. The lake has some inherent problems.

Konovsky’s main points:

  • Capitol Lake is too shallow and stagnant to control temperature.
  • 75 percent of the fine sediment coming down to the lake is natural.
  • The lake would need to be 300 feet deep to control algae blooms.

You can view Konosky’s entire presentation below: