The impaired water quality of the Yahara River chain of lakes, Mendota, Monona, Waubesa, and Kegonsa, can be seen in the number of beach closures due to potentially toxic blue green algae, the lack of water clarity, and the smell of decay from our over-fertilized lakes. Past efforts to clean the lakes of these problems led to improvements in the treatment of sewage and other point sources of pollution. Today’s challenge is to address phosphorus enriched runoff from urban and rural lands, known as non-point source pollution.
The Yahara CLEAN Strategic Action Plan for Reducing Phosphorus enumerates fourteen specific actions with clear achievable phosphorus reduction goals to clean the lakes. The actions promote proven, cost-effective urban and rural practices to address phosphorus pollution now. The goal of the plan is to produce dramatic improvements in lake water quality by achieving a 50% reduction in the average annual phosphorus load from direct drainage sources in the Yahara chain of lakes. If no other significant water quality threats intervene – and once phosphorus load reduction goals are realized – we will double the number of days when the lakes are clear, our beaches are open, and we will significantly reduce the number toxic algal blooms that limit recreational enjoyment of the lakes.
Overall, 71% of the phosphorus load reduction must come from rural areas. Fortunately, many farmers and livestock owners are already hard at work to reduce phosphorus enriched runoff. They will be intensifying their efforts to improve cropping, tillage, and in-field practices and managing manure and nutrients to meet the goals in the plan. Yahara Pride Farms will be supporting farmers in their phosphorus reduction efforts. Building more community manure digesters will be one important action to help farmers manage manure so that less phosphorus reaches area lakes and streams.
Overall 28% of the phosphorus load reduction comes from urban areas. It will be challenging to meet the phosphorus reduction goals in urban areas since so much of the land is developed and there is little opportunity to clear stormwater of phosphorus before it reaches the lakes. To meet this challenge urban residents and municipalities will be called upon to improve leaf management and control of construction erosion, stabilize urban waterway banks, and reduce the amount of total suspended solids from runoff in municipal stormwater.
Through the combination of urban and rural actions, we will reduce phosphorus loads into Lake Mendota by 53%, Lake Monona by 26%, Lake Waubesa by 50%, and Lake Kegonsa by 56%. Phosphorus reductions in the Lake Mendota watershed will provide additional benefits to the rest of the lakes since phosphorus from Mendota flows to each of the downstream lakes via the Yahara River. In the next few years, we will use emerging technologies, like alum additions in waterways, to further reduce the phosphorus load to Lake Monona and achieve the 50% target.
The estimated net cost to implement all the Yahara CLEAN actions is $78.6 million dollars, after a deduction of $49.5 million in private business investment in community digesters. The remaining funds will be raised through a combination of public and private sources.
In summary, the Clean Lakes Alliance and Yahara CLEAN partners support the following points:
It’s Possible… We can rehabilitate the lakes, doubling the number of “clear” water days
Commitment… We have strong commitment and partnerships to renew and expand the effort
Road Map… We have 14 actions to reduce phosphorus by 50% in each lake
Action… We are poised to take action as a community and involve all citizens in the efforts
Yahara WINs… We are in a pilot program to reduce rural and urban phosphorus enriched runoff, a partnership of 21 municipalities and several nonprofits
Support Clean Water… Support elected officials in their efforts to clean the lakes