Stop us if you've heard this before:
"West Okoboji is one of only three blue water lakes in the world, the others being Lake Geneva in Switzerland and Lake Louise in Canada."
Dr. John Downing isn't going to debunk the magic of Santa or tell you how coins end up where that missing baby tooth used to be. But, the Iowa State and Minnesota-Duluth researcher is an expert in his field. He can tell you the "blue" West Lake Okoboji claim just doesn't hold water.
File the information next to your University of Okoboji degree.
"It was said to me when I moved to Iowa about 22 years ago," Downing said. "I laughed at the time. It's a nice thought. We're all proud of our lakes and we love them. I think it's great people are that proud of Okoboji. It's a terrific lake – my family has actually been involved with Okoboji since my dad was a little boy."
It just isn't blue – but there's no need for the lakeshore property owners in Canada or Switzerland to feel superior.
"'There is, really, no such thing," he said. "It's not a technical appellation. It's something somebody made up. Actually, there are lakes that have blue water, but they're usually polluted with copper."
Other lakes appear blue when you look down in them, "but what you're usually seeing then is chalk particles in the water and the blueness of the sky is being reflected back up to your eye."
Downing is a limnologist – a person who studies lakes, rivers and streams. He's currently on leave from Iowa State University to do research at the University of Minnesota-Duluth. His current studies center around Lake Superior.
"Lake Superior is a phenomenally blue water lake – I mean it has water that appears very blue," he said. "It has some of the best water quality in the world, in fact. But, it also doesn't share much in common with Lake Louise, Geneva or Okoboji."
The researcher will oversee the Iowa Lake Monitoring Project until the end of the year. Findings suggest West Lake Okoboji benefits from its depth, its relatively small watershed it's groundwater input and a high dilution rate.
"It's a good clear water system," Downing said. "It's what we call mesotrophic, meaning it has a moderate amount of nutrients in it and it has pretty clear water. Certainly it has the clearest water, I think, of all the lakes in Iowa – just because it's deep. Not because we've behaved properly. It is able to absorb a lot of insult."
West Lake Okoboji's maximum depth is 134 feet, according to the Iowa Department of Natural Resources.
"If Okoboji were 20-feet deep like many other lakes in Iowa, it would not be so clear," Downing said. "It certainly is a terrific waterbody. I'm sorry to say there is no such thing, technically, as a blue water lake. …I think it's just a wonderful expression of people's love and dedication to that lake. It's special enough all on its own. I think it's wonderful that people want to call it something even more special."