Persistent wet weather has increased nitrate leaching from farm fields into rivers and is the main cause of the metro’s prolonged water crisis this summer, Matt Helmers, director of the Iowa Nutrient Research Center, tells Axios.
Why it matters: The consequences are apparent this year, but the problem has been getting worse for decades.
- Understanding it can help unify the state to achieve lower nitrate levels more quickly, urban, farm and public utility advocates tell Axios.
Catch up quick: Nitrate levels at key water intake points surpassed the federal drinking water limit of 10 mg/L for about 40 more days this year compared with 2024 — a near-record period, according to data from Central Iowa Water Works (CIWW).
- The DSM metro is also the fastest growing in the Midwest, creating a situation in which water utilities are struggling to remove enough nitrates to meet demand.
Flashback: In 2015, DSM Water Works — a member of Central Iowa Water Works (CIWW) — sued three northwest Iowa counties and multiple drainage districts in federal court, alleging they violated the Clean Water Act by not better controlling nitrates.
- The legal battle caused political division before a judge dismissed the lawsuit in 2017, concluding that the widespread problems are for the Iowa Legislature to address.
State of play: Metro water utilities have been working on nitrate removal expansions for years, with new projects expected to come online in 2026, CIWW executive director Tami Madsen tells Axios.
- Farmers are deploying dozens of types of projects like precision nitrogen management through the Iowa Nitrogen Initiative, an on-farm trail program at Iowa State University.
- The use of cover crops in Iowa has grown from 50,000 acres in 2010 to over 4 million acres this year.
Friction point: The work needs to be greatly expanded, environmental advocates such as Polk County Conservation director Rich Leopold tell Axios.
The intrigue: Nearly two-thirds of Iowans voted in 2010 to amend the constitution and establish the Natural Resources and Outdoors Recreation Trust Fund — a permanent funding source for clean water, outdoor recreation, and habitat projects…