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State Report Finds The Rate Of Impaired Iowa Rivers, Lakes, Streams Continues To Increase

Hundreds of portions of Iowa lakes, rivers, streams and wetlands remain impaired, according to the state's recent surveys. Advocates are calling for more regulation to improve water quality.
Kate Payne
IPR file
Hundreds of portions of Iowa lakes, rivers, streams and wetlands remain impaired, according to the state's recent surveys. Advocates are calling for more regulation to improve water quality.

Seven hundred and fifty segments of Iowa lakes, streams, rivers and wetlands remain impaired due to pollutants such as bacteria, algae and animal waste, according to the draft impaired waters list released Tuesday by the state Department of Natural Recourses. While fewer segments of waterbodies overall are impaired compared to the 2018 report, the rate of impairment has increased.

Sixty-one percent of the segments of the state’s rivers and streams that were tested and 67 percent of lakes and reservoirs tested were found to be impaired, a designation meaning they don’t meet water quality standards for at least one intended use, such as drinking water supply, recreation, or aquatic life.

Those rates have increased since the 2018 report, when 57 percent of rivers, streams, lakes and reservoirs tested were found to be impaired. The percentage of wetlands found to be impaired has remained consistent at 26 percent.

The overall number of waterbody segments that DNR staffers were able to assess has also gone down, from 1,422 segments in the 2018 report to 1,300 this year. Another 1,280 water body segments were not assessed as part of this report.

Since the 2018 report, 99 waterbody segments have been recommended to be removed from the impaired waters list, which includes “waters that are impaired or threatened” and still need a TMDL, or total maximum daily load, a limit on pollutants that sets targets to improve water quality.

According to the DNR, the waters have been flagged for delisting either because a TMDL has since been put in place, new data has been collected demonstrating water quality improvements, or due to an earlier assessment error.

The ongoing impairments cover every corner of the state, including Lake Pahoja in Lyon County, portions of the Upper Iowa River near the Minnesota border, and the Rathbun Reservoir in Appanoose County.

Segments of some of the state’s major rivers, which also serve as sources of drinking water, continue to have various impairments, including portions of the Des Moines, Raccoon, Iowa, Cedar and Mississippi Rivers.

Top causes of impairments for rivers and streams include high levels of bacteria and fish kills caused by animal waste and other toxins. Leading impairment causes in lakes, reservoirs and wetlands include algae, turbidity, pH levels and bacteria, as well as high levels of toxins in fish.

According to the state’s analysis, just 16 waterbody segments tested meet the standards for all of their designated uses.

DNR staffer Ken Krier said the findings are consistent with recent years, as far as the overall number of impaired waterbody segments.

“I would call it stable. I don’t know if we can really point to on direction of the other. Last cycle from 2016 to 2018 it was a 2 percent increase and we’re at a 2 percent decrease this cycle,” Krier said.

DNR staffers have cautioned against trying to interpret overall trends in the state’s water quality based on the report’s findings, which can vary year to year based on changes in methodology and other factors. But Alicia Vasto, a water policy specialist with the Iowa Environmental Council, says the analysis indicates that the state’s current approach to water quality isn’t sufficiently protective.

“It tells us that, as previous lists have told us, that our water quality is not improving in the state. And we believe the voluntary approach that the state is taking to water quality is not sufficient,” Vasto said. “What we really need is regulation. If we’re going to see any actual improvement in water quality in this state we need to have requirements and we need to have metrics.”

The Sierra Club Iowa Chapter also raised concerns over the findings, releasing a statement saying the report demonstrates “that Iowa has a major water quality crisis”, and pointing to the state’s animal agriculture industry as a major driver.

“Iowans should find it very alarming that of the waterbodies tested, 84 percent of Iowa’s rivers and streams, and 70 percent of Iowa’s lakes and reservoirs are impaired or potentially impaired,” said Conservation Coordinator Jess Mazour in a written statement. “It’s time to pass a moratorium on factory farms and get serious about improving water quality in the state.”

The DNR is taking public comment on the impaired waters list over the course of this month. Iowans can submit their comments to IRcomment@dnr.iowa.gov.

Kate Payne was an Iowa City-based Reporter