Most of Iowa’s monitored rivers and streams now show steady to declining levels of nitrates and phosphorus thanks to a new interactive tool developed by the U.S. Geological Survey (USGS).
The USGS is designed to track long-term trends in surface water quality.
“The new USGS tool clearly shows that the work by Iowa farmers to reduce nutrient losses produced positive trends in the 10 years leading up to 2012,” said Rick Robinson, Iowa Farm Bureau environmental policy advisor.
The new USGS tool combines information on water quality collected by a variety of groups, including the USGS and the Iowa Department of Natural Resources.
It is designed to provide a look at changes in the quality of water in rivers and streams in the four decades following the passage of the Clean Water Act in 1972, the agency said.
The tool can be used to look at water quality measures beyond nutrients, including pesticides concentration and aquatic-life metrics, such as the types and numbers of fish. In all, some 1,400 sites were monitored nationwide between 1972 and 2012.
Iowa’s monitoring sites are spread all over the state and include sites along the Raccoon, Des Moines and Cedar rivers.
“The overall impression one gets from the USGS interactive map is that trends were moving in the right direction prior the state’s Clean Water Initiative,” said Robinson.
“There is clearly more work to be done, and there can always be weather-induced spikes in the short run, but these results, along with the trends we have seen since 2012, make it clear that farmers have stepped up to improve Iowa’s streams, rivers and lakes.”