Study from UW researchers finds little change in lake quality

In the midst of ongoing statewide debates about ties between poor water quality and certain ag practices, a recent study from UW-Madison researchers paints a surprisingly static picture.

In a study of 2,913 lakes from 1990 to 2011, researchers found that “despite large environmental change and management efforts over recent decades, water quality of lakes in the Midwest and northeastern U.S. has not overwhelmingly degraded or improved.”

The study defines environmental change as coming from urban expansion, changes in atmospheric climate and “agricultural intensification.”

CAFOs, or concentrated animal feeding operations, pack a large number of animals into smaller areas than traditional dairy farms, upping profitability but also creating much more waste. So much waste is produced that the state requires their operators to create detailed plans for how they will safely handle it.

These and other new agricultural models have been cropping up all over the country since the 1970s, while the federal government has been spending billions to keep runoff nutrients out of bodies of water. These nutrients feed the growth of algae like the toxic blue-green variety found earlier this summer in Madison’s Lake Mendota.

Though the study found little change in most lakes’ overall quality, some trends were identified: about 10 percent of study lakes were getting “greener” with more algae blooms and greater plant life, while about 5 percent saw clearer water conditions.

Overall, the majority of lakes did not see much change in the two-decade study period. Samantha Oliver, lead author for the study and grad student at the Center for Limnology, chalks that up to a cancellation effect, where pollution is balanced out somewhat by programs and efforts to reduce it.

She says without programs like the national Clean Air Act, Clean Water Act and others “holding the line,” the situation “would be much worse.”

“We’re barely keeping up,” she told

One way to improve the situation, Oliver said, is to shift water quality management efforts so that they are more big-picture, incorporating how various water systems affect one another and the downstream impact of upstream pollution.

Though this concept is from a national perspective, Oliver says it’s definitely applicable on the state level.

“These connectivity issues in freshwater systems are relevant at the local scale and the national scale,” she said. “It’s totally relevant to the watershed concept — farms being managed far away from the body of water still affect it downstream.”

And, she added, efforts at the state level would be doing more to improve lake water quality if they were better aligned so that state dollars went to where they were most needed.

She said other UW researchers have shown that money from state water quality improvement programs isn’t always going to the same area as where the problems are located. She adds the effort to equitably provide funding to the state’s farmers has actually led to a disconnect between certain efforts and real, positive environmental impact.

“Spatially integrated approaches would go a long way,” she said.

Oliver says other scientists have taken these findings as positive or negative, depending on their perspective. Some, she says, see this as validation of the impact of water management efforts, while others are disheartened that these efforts haven’t made more of a difference.

“I think both of those interpretations are valid,” she said.

–By Alex Moe