COVID-19 Response

For information about fall semester instruction and campus operations, please visit

During this time, please contact us at

UW-Madison Survey: Dane County Residents Would Pay A Lot For A Cleaner Lake Mendota

Several years ago, the Wisconsin Department of Natural Resources announced a program to clean up Lake Mendota at a cost of almost $18 million over 10 years. However, county residents say they”d be willing to pay $52 million for the job, according to a University of Wisconsin Madison survey.

“Our survey results are clear evidence that the benefits of the current effort to improve the lake”s water quality far exceed the project”s costs,” says Richard Bishop, a natural resource economist in the College of Agricultural and Life Sciences. “The survey as well as preliminary focus groups we held here in Madison showed that people in Dane County are deeply concerned about Lake Mendota.”

Bishop says the question of the project”s value came up in one of his classes, which then began the research. Two students in that class — Basil Stumborg and Kenneth Baerenklau — are now graduate students in the Department of Agricultural and Applied Economics. They completed the study with Bishop.

The researchers found that the average Dane County household was willing to pay $338 over 10 years to improve water clarity and lake weeds, and reduce the frequency of summer algal blooms from one day out of every two days to one day out of every five days.

The average respondent was a 48-year-old man with an annual household income of $62,400. The study found that no respondent was willing to pay more than one percent of his or her annual income to clean up Lake Mendota. Among the other findings:

oPeople with higher incomes or more education were willing to pay more than those with less income or education.

oPeople with houses close to the lake were willing to pay more for cleanup than people with houses farther away.

oYoung people were willing to pay more than those who are older.

oWomen were willing to pay more than men.

Madison and adjacent communities surround Lake Mendota, a popular recreational site. Area residents have been concerned about the lake”s water quality for decades. The lake”s primary problem is excessive phosphorus runoff from a diffuse set of agricultural and urban sources. The phosphorus feeds foul-smelling, unsightly algal blooms that reduce the pleasure people take in activities on the lake and along its shore.

The problems of Lake Mendota are typical of those across the country, Bishop says. Nonpoint source pollution is the leading cause of water quality problems in most states, according to the U.S. Environmental Protection Agency. And nutrient-rich runoff is one of the chief problems affecting the country”s lakes, rivers and estuaries.

In summer, Mendota has algal blooms about half the time. Long-term studies by limnologists with the UW-Madison and Wisconsin Department of Natural Resources show that reducing phosphorus entering the lake by half — as planned under the current Wisconsin DNR program — would reduce the bloom frequency from 50 percent of summer days to 20 percent of the days.

The 50-percent phosphorus reduction for Lake Mendota was estimated to cost $17.8 million over 10 years, with more than half the money coming from land owners and communities, and approximately $8.6 million from a Wisconsin DNR program. The lake and its watershed are part of Wisconsin”s Nonpoint Source Pollution Abatement Program. The program provides cost-sharing grants and technical support to help landowners and communities that voluntarily decide to install and maintain practices that reduce pollution. For instance, money will go to farmers in the watershed to defray the costs of installing and maintaining practices such as stream-side buffer zones, livestock fencing, runoff diversion and wetland restoration. Municipalities are eligible for funds for activities such as increased street sweeping and storm water detention ponds.

Bishop, Stumborg and Baerenklau conducted a random survey of 500 Dane County residents in December 1997. The survey, in referendum format, asked residents how each would vote on a proposed government program to make the improvements in Mendota”s water quality. Each respondent was asked if he or she would support the program if it would increase the taxes on that household by a particular figure. Amounts ranged from $0 to $300 per year over 10 years. Based on the survey, along with income and demographic information, the researchers projected the survey response to the county-wide estimate of $52 million.

The research was supported by: state funding to the UW-Madison College of Agricultural and Life Sciences; a National Science Foundation grant to the UW-Madison Center for Limnology; and a Pew Foundation grant to UW-Madison limnologist Stephen Carpenter.