Water: a decorahnews.com special report

Extreme weather trends are causing the issue of water quality to be of greater concern to some Iowans, particularly to those living in urban areas.

Although agricultural runoff contributes the largest portion of nutrients to the state's waters, significant rain events like the one seen on Tuesday night, which dropped seven inches of rain on Decorah, can play a big part in the spread of nutrients like nitrogen and phosphorous, among other things, to water sources.

According to Iowa's Nutrient Reduction Strategy, urban areas contribute 8 percent of the excess nitrogen and 20 percent of the excess phosphorous in the water, and heavy rainfall and flooding can increase the rate at which these nutrients are dispersed.

Although there is still some debate on this issue, as the National Weather Service in La Crosse maintains that rainfall trends are normal for Northeast Iowa, many other scientists and policy makers remain unconvinced that climate change is not playing a part in recent heavy rainfalls.

"Long term climatologists are reluctant to say if there is change in rainfall, whether it's more or less than before," Winneshiek County Supervisor Dean Thompson said. "But we've certainly had more than our fair share this summer, particularly heavy rainfall events, so I am perfectly happy to say that."

According to Thompson, despite proof of any empirical changes in rainfall, water quality is a two-sided issue, and responsibility cannot be solely placed in the hands of agriculture.

"When we see high levels of N and P in the water and algal blooms, everybody wants to point the finger at farmers," Thomson said. "But what about homeowners who fertilize and use herbicides right down to the water's edge--that all contributes. I don't know to what extent that is happening in Decorah, but it is happening."

Thompson said that conservation efforts for storm runoff are already being put forward in the agricultural community and this needs to be done in urban areas as well.  Luther College biology professor Dr. Jodi Enos-Berlage, who does research on a watershed north of Decorah, agrees with Thompson.

"The bottom line is that we humans have not built or designed urban or agricultural infrastructure to handle extreme weather events," Enos-Berlage said. "Whether it is the design of a city (not the best idea to build on a floodplain), or a feedlot with insufficient runoff controls or cornrows planted with insufficient conservation practices."

The city of Decorah has recognized this issue and has already put forth a proposal to create a new storm water utility for the municipality. The money from the new utility will go directly to creating and managing the infrastructure to deal with heavy amounts of storm runoff.