Waldo Lake
DB: This is Earth and Sky, on Waldo Lake.
JB: Nestled in Oregon’s Willamette Valley, this natural lake is so pure that if you lower a black and white Frisbee-shaped disc into its depths, you won’t see the disc disappear for at least 40 meters – over 130 feet. In fact, Waldo Lake rates as one of the cleanest lakes in the world. Deigh T. Bates is Soil & Water Program Manager at Willamette National Forest. He says it’s like looking at 6,000 acres of distilled water.
DB: But the very purity of the lake’s water puts it at risk for changes in water quality. And Bates and other scientists have noted changes. Nutrient levels are still low, but they’re creeping upwards. And the lake’s resident phytoplankton and zooplankton communities are changing, too.
JB: Any number of factors could be causing the changes. Air pollution in rainwater could be a factor. Natural events, like a local wildfire in 1996, could be partly responsible. And more people are visiting Waldo Lake and the Willamette Valley. Managers have erected new state-of-the-art composting toilets around the lake to help reduce local nutrient input. And they’ve built an informational kiosk to educate visitors.
DB: Now more basic scientific research is needed – to determine the main cause of Waldo Lake’s changing water quality. That’s our show – made possible in part by the National Fish and Wildlife Foundation. We’re Block and Byrd for Earth and Sky.
Our thanks to the following individuals and institutions who assisted in the preparation of this script:
Thanks to:
Deigh T. Bates
Soil & Water Program Manager
Patty Rogers
Communications
Soil & Water Program
Willamette National Forest
Eugene, OR
Author’s Notes:
Interview with Deigh T. Bates and Patty Rogers
Waldo Lake is located in Oregon. It’s of such high quality that it is basically 6,000 acres of distilled water. By all measures of water quality (physical, nutrient, Secci disc, etc.) it is completely off the scale. The lake is much purer and cleaner than most lakes. In fact it is one of the cleanest lakes in the world (special techniques are used to monitor its quality, because it’s so pure).
It’s still incredibly clean-off the scale clean-but over the last 35 years Waldo Lake has seen some quality changes. Just in 1999, you could see a black and white Secci disk down to an exceptional; 40.5 meters!!
But there are some problems. Nutrient loading is changing the chemical and biological processes of the lake. As a result of this, the local scientists and managers have effected some changes. First, there is now and an information kiosk as you enter the lake area that explaining what visitors can do to help preserve the lake’s pristine integrity. Second, camping on the center island of the lake has been banned. In addition, all area toilets were assessed, and even though they passed tests of leakage, they were all removed. New, modern and extremely clean composting toilets have been installed. These toilets will not leak nutrients into the nearby lake. Finally, local waste and dumpsites have been closed.
But, say scientists, as the population of the surrounding Willamette Valley increases, so will the region’s nutrient loading. Nutrients can enter the lake via the streams that feed it, via air pollution and subsequent rainwater, and simply by increasing the number of people and recreational activity in the area. Shifts in nutrient levels are currently occurring in the lake-along with related sihfts in its resident phyto and zooplankton communities-but its not clear yet exactly what is causing the shifts. It could be any or all of the possibilities listed above. There’s a five-year science study proposed to help clarify what’s going on in the lake, but it hasn’t been funded yet. Thus, the lake is monitored as closely as possible with the staff and funding currently available. Current managers say there’s not enough information yet to tell whether current changes are “natural” or more related to human impacts.
“It’s a very large lake in a very small watershed,” says Deigh Bates. “There are no permanent streams-the water enters in the spring and winter from seasonal, snowmelt streams.” In fact, the lake covers about 10 square miles of its tiny 31 square mile drainage basin.
Adds Bates, “This is a very unique and special lake. It’s the second largest natural lake in Oregon. It’s incredibly clean and pure. And it’s simply gorgeous up there. People from the U.S. and around the world visit and people often return because they hold its beauty and integrity in such high esteem. Plus, there’s an international science community very interested in this lake.”
The lake is probably so incredibly clean, at least in part, because of its geology. It’s a large lake that resides in an unusually small watershed-so doesn’t see a huge amount of run-off. Plus, local soils are coarse and are a kind of natural filtering system for water that does enter the lake.
Fire is also a part the lake’s natural history. In fact, wildfire burned to the northern edge of the lake in 1996. Historically, fire has had a more important role in the lake’s natural ecological processes than the more recent activities of humans. But so far, because of the lack of funding and research, it’s not clear how dramatic the effects of these various impacts (humans, fire, etc.) are on the lake.
Additional Teacher Resources
USDA Forest Service, Willamette National Forest: Waldo Lake Basin Management
Waldo Lake is on the largest natural lakes in Oregon. It is the second deepest natural lake in the state. It nestles against wilderness and is the headwaters of the North Fork and Middle Fork of the Willamette River, a National Wild and Scenic River. A brief natural history of the lake and its astonishing water purity.
