Healthy Floodplains Reduce Nutrient Pollution By Olivia Dorothy Six key floodplain restoration designs can maximize nutrient removal in rivers. This blog was written by Olivia Dorothy, Upper Mississippi River Basin Director, American Rivers & Brad Gordon, 2017-2019 American Rivers Lapham Fellow, currently the Southern Minnesota Program Manager at Great River Greening In the Midwest, nitrogen and phosphorus pollution from farms is a persistent problem. In excess, these nutrients, which plants need to thrive, can cause toxic conditions in lakes, rivers, streams and aquifers. Too much nitrogen in a water supply can interrupt the delivery of oxygen to your body’s cells, which can lead to death, particularly in infants. Both phosphorus and nitrogen pollution can also contribute to toxic algae blooms in lakes, rivers and estuaries. The over-production of blue-green algae can suck all the oxygen out of the water column and cause massive fish kills. Some types of algae can also produce a toxin, microcystin, that can cause a range of stomach problems and liver failure.