Arrow-right Camera

The Spokesman-Review Newspaper The Spokesman-Review

Friday, October 30, 2020  Spokane, Washington  Est. May 19, 1883
Partly Cloudy Night 36° Partly Cloudy

Outdoors blog

Blue-green aglae warnings for Rufus Woods, Potholes

WATER SPORTS -- Campers and boaters must be aware of toxic alage warnings for a portion of Potholes reservoir and Lake Rufus Woods.

The Washington Department of Health is warning people not to swim in Rufus Woods, but officials say the problems does not affect fish or fishing.

However, pets and livestock should be kept away from the water.

The Department of Ecology has a website devoted to algae issues

Read on for a details story from the Grand Coulee Star Online plus links to

by Scott Hunter

Fishing is OK, but officials are telling people not to swim in Rufus Woods Lake because of a dangerous type of algae discovered near Chief Joseph Dam.

It’s not clear whether the danger also lies farther upstream in the reservoir that is in the Columbia River downstream from Grand Coulee Dam.

An unsafe level of algae toxin has been discovered there, prompting the U.S. Army Corps of Engineers to post Washington State Department of Health warnings against swimming, water skiing and other in-water activities at the lake.

While it’s safe to eat properly cleaned and gutted fish, the water should not be consumed and steps should be taken to keep livestock and pets away from the water. Boaters are advised to avoid areas where algae blooms are present.

Most people certainly wouldn’t knowingly swim in algal scum, but their dogs don’t care, noted Dept. Ecology biologist Kathy Hamel. Two dogs died from that last year, she said.

“Whatever they do, they should not let their dogs swim in it,” she said.

In a river setting, the scum is likely to gather in backwater areas, but clear, flowing river is likely free of the goop.

Potholes Reservoir was also declared unsafe on Monday, Grant County Health District announced.

According to the state Dept. of Ecology’s website:

“Blue-green algae blooms pose a human health concern and have killed pets and livestock. Although most blue-green blooms are not toxic, some blue-green algae produce nervous system or liver toxins. Toxicity is hard to predict. A single species of algae can have toxic and non-toxic strains. A bloom that tests non-toxic one day can become toxic the next day.

“People may become ill after swimming or water skiing in lakes with toxic blue-green algae. Human health effects may include stomach pains, vomiting, diarrhea, skin rashes, and nerve and liver damage. …

“Blue-green algae are actually bacteria called cyanobacteria. They can create problems when they form blooms. The blooms happen mostly in the summer or fall, but can occur anytime. Blue-green blooms may float to the surface and can be several inches thick near the shoreline. A blue-green algae bloom often looks like green paint floating on the water and is hard to pick up or hold.”

The toxin of concern is anatoxin-a, a naturally occurring nerve toxin produced by some blue-green algae blooms, which has been shown to be lethal to animals if ingested at high enough concentrations.

Samples from the lake were taken and forwarded to King County Environmental Laboratories for testing and analysis, the press release from the Corps, said. Two separate sample test results showed the lake contained 6-31 micrograms of anatoxin-a, a powerful and quick-acting toxin, per liter of water.

The state’s departments of Ecology and Health have notified the Corps that the analyzed samples are in excess of the state recommendation of one microgram per liter for recreational uses of the water. Samples will continue to be taken and analyzed weekly until anatoxin-a levels are determined to be below state recreational guidance values.

Access to Rufus Woods Lake remains open to the public.

Outdoors blog

Rich Landers writes and photographs stories and columns for a wide range of outdoors coverage, including Outdoors feature sections on Sunday and Thursday.

Go to the full Outdoors page