Lack of lake warnings puzzles experts
A welcome mystery is puzzling county, state, and federal officials this summer.
As inexplicably as blue-green algae arrived 15 years ago at Marion Reservoir and Marion County Lake, they just as inexplicably have vanished.
Experts are unanimous in saying they wish they could take credit for fixing whatever problems led to a decade and a half of relentless weekly warnings about the two lakes.
But they say they have done nothing to address the problem, the cause of which they did not fully understand in the first place.
Whatever the reason, not a single warning or watch about potentially toxic algae has been issued for lakes in Marion County this summer.
And they are not only bodies of water to suddenly “heal.” Milford Reservoir in Clay, Geary, and Dickinson counties, another fixture on the warning list, also has had no watches or warnings.
Advisories continue for a large number of other lakes in the state.
Warnings for 11 lakes in Atchison, Grant, Johnson, Osage, Saline, Sedgwick, Rooks, and Wabaunsee counties were issued this past week, and watches were issued for two other lakes, in Douglas and Shawnee counties. But, as has happened every week all summer, none were for lakes in Marion County.
“It’s a pleasant mystery; I’ll take it,” assistant Marion Reservoir manager Kevin McCoy said. “Still, it can happen at any time, so knock on wood.”
A state fish biologist visited Marion County Lake on Thursday and was puzzled as well, lake manager Isaac Hett said.
“We were just talking about this,” Hett said. “Four or five lakes are kind of in the same situation, and no one is sure why.”
Both Hett and McCoy, along with state experts, insist that state monitoring procedures have not changed.
“They are taking their water samples the exact same way in the exact same place,” Hett said.
All that a spokeman for the Kansas Department of Health and Environment could say when asked to explain the situation was, “That’s a very good question.”
She and a spokesman for the Department of Wildlife, Parks, and Tourism forwarded the query to top state scientists. But so far they have been unable to offer an explanation, either.
A working theory is that this year’s extreme drought may have played a role even though previous droughts did not seem to affect algae counts, which tend to rise when water is shallow, warm, and stagnant.
“There’s no proof of it,” Hett said, “but with the drought we haven’t had any runoff from farm fields. It’s a pain that the lakes are so low, but it may also be kind of a blessing.”
The reservoir also is low — three feet below its normal level, McCoy said.
That’s the lowest July level for the reservoir since 2013, when it was almost half a foot lower, according to Corps of Engineers records. However, in 2013, the reservoir was under algae warnings or watches most of the summer.
The lack of algae warnings, which in the past have been blamed for curbing tourism at the two lakes, has not generally been felt.
Part of the reason may be the regular drumbeat of warnings in the past.
“We get plenty of questions about it because people almost expect it,” McCoy said.
Hett agreed, saying his office receives multiple calls each week asking whether the lake is under an algae advisory.
McCoy has noticed no increase in recreational use of the reservoir in the absence of advisories.
“Recreation still is going on but it’s not really up,” he said. “But that’s probably because we’re three feet short on water. And hot summer days don’t necessarily mean more visitors anyway. Some people stay home in the heat.”
Hett, on the other hand, said his staff had noticed an increase in campers at the county lake.
“We have a lot more, especially boaters and swimmers,” he said. “A lot of people didn’t want to be in the water before.”
Blue-green algae, scientifically known as cyanobacteria, actually are not a single thing.
They come in multiple varieties, some of which are actually harvested for use as nutritional supplements.
The problem is, it’s difficult to determine exactly which varieties are present in a sample. Some are potent neurotoxins, as potentially lethal as nerve gas, and others have been associated with liver damage and cancer.
When a body of water is under a warning, it’s unclear which varieties are present, and different varieties may be present at different locations.
Cyanobacteria are difficult to remove in treatment of drinking water because normal techniques kill and crush the algae, which is when toxins are most likely to be released.
Marion and Hillsboro water treatment plants, which also supply drinking water to Peabody and county lake residences, have installed costly ozone systems that effectively remove the toxins.