Iowa River flooding, Louisa County, 2008

Clean Water

Animal Feeding Operations in Iowa Floodplains Report

A risk to Iowa's waters

New report details animal feeding operation (AFO) construction and expansion in Iowa’s 100-year floodplain.

Pie chart showing 71 new animal feeding operations have been added to Iowa's 100 year floodplain since 2003. An additional 27 have been added to the 500 year floodplain

AFOs in Iowa’s Floodplain

Since 2002, Iowa law has prohibited new and expanded confined AFOs on the 100-year floodplain. The legislature charged the Department of Natural Resources (DNR) with developing a floodplain map to identify the areas to apply the construction restrictions. However, since that directive, DNR has not developed or adopted the floodplain map more than 20 years later.

Iowa has seen both extreme and long-term flooding throughout the state since 2002. When a manure storage structure floods, it can pollute waterways with pathogens, nitrogen, and phosphorus. In the twenty years since the floodplain exclusion law passed, the DNR has been operating under a case-by-case approach to site review. The analysis found that DNR’s interim process has not done an adequate job of preventing AFO construction and expansion in the 100-year floodplain.

“This report illustrates the consequences of failing to comply with the law. We cannot afford for the state to wait any longer.”

The outcome of climate change increasing precipitation and flooding in Iowa also plays a major factor in considering the efficacy of the two-decade old law.

The Environmental Working Group performed geospatial analysis on AFOs in Iowa’s floodplains. Building on that data, in this report, the Iowa Environmental Council and ELPC call on DNR to follow state law and adopt an official 100-year floodplain map as part of the the department’s current rulemaking process, while also urging state leaders to consider whether the current law is protective enough. The groups have previously petitioned the DNR on the issue, and the petition remains under DNR review.

“Iowa law recognizes that animal feeding operations are unsafe in a floodplain where floodwaters can carry pollutants into rivers that provide Iowans with drinking water and recreational opportunities,” said Josh Mandelbaum, Senior Attorney at ELPC. “We have been waiting for decades for DNR to adopt a floodplain map to implement the law. This report illustrates the consequences of failing to comply with the law. We cannot afford for the state to wait any longer.”

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