No silver bullet for improving Madison lakes

Efforts to date have brought limited results, so Dane County proposes sucking out contaminated muck.
No silver bullet for improving Madison lakes

By most accounts, it’s been a good year for the Madison lakes.

Ample rain kept water levels high and a limited amount of algae made for some nice boating and swimming conditions. Participants in September’s Ironman Wisconsin enjoyed some of the clearest water ever for their event.

Still, the Yahara Chain remains plagued by nagging problems fueled by the amount of nutrient laden-material that runs off streets, lawns and farms fields. And despite well-publicized efforts to improve water quality—and millions of dollars spent—limited progress has been made in cleaning up the lakes.

One reason is that there are already tons of fertilized muck sitting in the streams from decades of uncontrolled runoff. One good gully-washer flushes that stuff right into the lakes.

A recent study found that even if you stopped any new nutrients from reaching the lakes—something nobody has figured out how to do—the stream bottoms flowing into the lakes hold enough phosphorus to keep the water polluted for another 60 years. 

Removing these so-called “legacy nutrients” is why Dane County Executive Joe Parisi is proposing to spend $12 million over four years in his new budget to dredge 33 miles of waterways leading into the Yahara Chain of Lakes.

The plan, which still needs approval by the full Dane County Board, calls for using vacuum equipment to literally suck up the muck and haul it away. It’s unclear if the mud would go either to a landfill or spread somewhere else as fertilizer.

One of the biggest obstacles to addressing contaminated runoff is that farms fields are largely exempt from the 1972 Clean Water Act. That groundbreaking law required states to limit water pollution from factories, sewage plants and storm sewers but left it voluntary for most agricultural uses.

Wisconsin has been a leader in trying to work with farmers to control manure and contaminated runoff but a lot of the damage has already been done, including in Dane County where large dairy operations remain key to the local economy.

Advocacy groups like the Madison-based Clean Lakes Alliance have been successful in raising public awareness about why the lakes often turn green and smelly each summer. The non-profit, which grew out of a coalition of water skiers and lakefront property owners, continues to work on education and outreach.

But at a certain point, some lake cleanup efforts come down to elbow grease.

I have long dreamed of a sort of “Lakes Patrol” that would simply clean the trash, dead fish and assorted flotsam from the public shoreline. Dane County already uses giant floating lawn mowers to harvest lake weeds, so why not extend that initiative even further with a giant vacuum to suck up the rest?

Those kinds of mechanical approaches could go a long way toward improving the image of the lakes, if nothing else. Few things say “yucky water” more than empty beer cans and plastic grocery bags floating in a clump of weeds in Monona Bay.

In terms of money, Dane County has calculated that dredging phosphorus from the streams is 15 to 20 times less expensive pound-for-pound than other measures that have been attempted—like the troubled manure digester program that led to several well-publicized spills of cow manure and a dangerous explosion.

At the same time, residents should realize that the Madison lakes are never going to resemble those crystal clear inland waters of Canada or Minnesota no matter how much money is spent. Not only are they geologically different from the northern lakes, they have been abused by humans for decades.

In 2007, now-retired DNR lakes expert Dick Lathrop warned that the “eutrophication” or early aging of the Yahara lakes has been going on since the mid-1800s when European settlers first altered the landscape. Over a century of unregulated heavy agricultural uses left their mark. In addition, inadequately treated sewage flowed directly into Lake Monona until 1936, and Lake Waubesa until 1958.

That’s a lot of repair work.

Mike Ivey is a Madison-based writer whose journalism career includes 30 years at The Capital Times.