Iowa's Low Hanging Fruit

Stream Buffer Rule = Cleaner Water, Little Cost

February 3, 2015

Iowa's Low Hanging Fruit: Introduction

Water quality in Iowa is notoriously poor and is not getting any cleaner. The primary cause is fertilizer and manure that runs off farm operations. This polluted runoff overloads waterways with nitrogen and phosphorus and sets off a cascade of harms that threaten human health and often make fishing, swimming or paddling in streams and rivers a very unpleasant experience, especially in summer.

Moreover, the polluted runoff from farm operations in Iowa and other farm belt states eventually reaches the Gulf of Mexico, where every summer it helps to trigger the infamous Dead Zone where marine life cannot survive.

In 2008, a consortium of federal and state agencies produced the Gulf Hypoxia Action Plan that called on the 12 states bordering the Mississippi River to develop strategies to reduce nutrient pollution in order to shrink the size of the Dead Zone. In May 2013, Iowa responded with its Nutrient Reduction Strategy, which seeks to cut nitrogen pollution from nonpoint sources – mostly farm operations – by 41 percent and phosphorus pollution by 29 percent.

The accompanying science assessment evaluated the effectiveness of various measures that could stem polluted runoff.

The science assessment reported that putting 35-foot wide grass strips between Iowa’s waterways and adjacent cropland could cut phosphorus runoff by 18 percent and nitrogen pollution by 7 percent. By itself, this simple practice – called streamside buffers – would get the state almost two-thirds of the way toward the goal for cutting phosphorus pollution. It would also get nearly a fifth of the way toward the nitrogen pollution goal. Streamside buffers would also reduce the sediment that clogs Iowa’s waterways as well as create new wildlife habitat.

EWG analyzed five Iowa counties – using high-resolution aerial photography and geographic information systems – to see just how many landowners would be affected by a streamside buffer standard and how many acres of grass strips would be needed to create buffers 35-, 50- or 75-feet wide.