"We are conservation planning for averages, not extremes"
April 21, 2011
Data collected by scientists at Iowa State University suggests that topsoil erosion in Iowa is much worse than thought
, due to extremely heavy rainstorms over the last few years and pressure placed on conservation measures by very high corn and soybean prices. As commodity prices rise, land that was previously either unsuitable for row crops due to erosion -- or that was designated specifically for conservation -- is being put into use growing crops
, which can increase the risk of soil erosion into the water. An analysis of the ISU data by an advocacy group called the Environmental Working Group
concludes that portions of western Iowa are losing topsoil much faster than the statewide averages suggest.
Soil erosion is just as much a matter for water quality as it is for agricultural production. That's why products like turbidity curtains
are used to prevent stormwater from carrying runoff into otherwise clear creeks and streams. Erosion also can carry fertilizer (including animal manure used for fertilizer) into waterways, which can contribute to high nitrate levels. (See a recent article on nitrate contamination to which we contributed in the recent Nebraska AWWA journal
.) Please feel free to contact us
with your questions about how to control erosion and how to manage its effects on public water systems.
last revised April 2011