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:

DNR partners with Department of Ecology, Squaxin Tribe and South Sound Salmon Enhancement group to restore Puget Sound

From the DNR blog Ear to the Ground:

DNR and its partners have removed 3,150 square feet of overwater docking structure — the last remaining overwater structure on Squaxin Island. Removed were 48 creosote treated wood pilings and 84.6 tons of creosote treated wood.

The dock, which provided tribal members access to an old long house on the island, is the second phase of creosote removal for this project. A 400-foot rock bulkhead along the Squaxin Island shoreline, adjacent to the dock, was also removed by the South Sound Salmon Enhancement Group.

Squaxin Island has documented surf smelt spawning habitat in that area. Removal of the treated wood and over water structures will improve the habitat for the smelt, as well as other species, such as migrating salmon.

Large structures that are built in the nearshore environment have been known to cast large shadows in the shallow waters that are used for migrating fish. These shadows are seen as a threat causing the fish to swim around them into deeper water where predators can eat them.

By keeping the nearshore clear of overwater structures that block sunlight and don’t contain toxic chemicals, we can help improve migratory corridors for our fish that we depend on.

Photos courtesy of Monica Shoemaker/DNR

Photo: Monica Shoemaker/DNR