The nitrate removal facility of Central Iowa Water Works has been running for 107 days so far this year. The facility activates when nitrate levels elevate in the Des Moines and Raccoon rivers, the two main sources for drinking water in central Iowa. In recent years, the levels have trended upward, says David Cwiertny, a professor at the University of Iowa.

As a new flood season approaches, many Americans remain haunted by the last. But Iowans are fortunate — we have access to the incredible tools developed and maintained by engineers at the state-funded Iowa Flood Center.