The Madison area is making real progress at cleaning up its lakes.
About 7,400 pounds of weed-feeding phosphorus was diverted from reaching our waterways last year, according to the 2014 State of the Lakes annual report, released this week.
That’s significant, because every pound of phosphorus can produce 500 pounds of lake algae. It’s those algae blooms that close beaches and stink up the shoreline with green soupy muck.
With help from Dane County, farmers northwest of Lake Mendota adopted better conservation practices last year on almost 8,000 acres of land, preventing 2,710 pounds of phosphorus from reaching our lakes. Better manure management also limited manure spreading on fields, diverting about 1,100 pounds.
In Madison, more inspections and better erosion control at construction sites blocked 420 pounds of phosphorus. In addition, volunteers cleared 50 dump-truck loads of invasive shrubs to help restore and preserve wetlands.
The annual lakes report, published by the Clean Lakes Alliance, highlights lots of diverse examples of success — with more to come. Madison, for example, is studying ways to keep leaves from decaying in streets and washing into storm sewers that lead to the lakes, while DeForest is encouraging homeowners to handle leaves better. Those efforts could divert 4,100 pounds of phosphorus.
But there’s still a long way to go to get to the shared community goal of reducing phosphorus in our Yahara chain of lakes by 50 percent by 2025. That’s the level scientists believe is needed to consistently have clean lakes every summer. Reaching that goal will require diverting an estimated 46,200 pounds of phosphorus, which is six times more than what’s been accomplished so far.
Climate change also could hamper efforts. That’s because heavier rains from stronger storms could wash more phosphorus-laden material off the land. And as the region continues to grow, more roads, driveways and other impervious surfaces will speed falling rain to storm sewers. At the same time, higher milk production on farms will mean more phosphorus-rich manure.
Yet the goal of consistently clean lakes is doable, with lots of creative approaches underway or being explored.
Last year wasn’t too bad for stinky, sloppy scum along the water’s edge. And area beaches were open about 95 percent of the time, according to the report.
Water clarity improved on all of Madison’s lakes last year. And slightly cooler water helped discourage blue-green algae blooms, which are the most dangerous for swimmers. Rainfall was average last year and down a lot from 2013, which helped ease runoff, according to the report.
Lakes Mendota and Monona, which are deeper, enjoyed good water quality. But the shallower Waubesa and Kegonsa had higher phosphorus levels.
Lake Wingra had the best water quality, in part because of the 2008 removal of carp, which stir up phosphorus-laden material from the bottom of the lake.
Madison and the region need to stick with what’s working and find more ways to block lake pollution. Visit cleanlakesalliance.com to learn how you can help.