DES MOINES COUNTY — Iowans interested in efforts to improve water quality at Big Hollow Lake can now review and comment on the Iowa Department of Natural Resources’ (DNR) updated improvement plan. A presentation outlining the findings and proposed solutions is available through September 8 on the Iowa DNR’s YouTube channel.
Big Hollow Lake, located in Des Moines County, is currently listed on the state’s impaired waters list due to high levels of algae, elevated pH, and turbidity—issues primarily driven by excessive phosphorus entering the lake. These water quality problems affect both recreational use and aquatic ecosystems.
The study, formally known as a Water Quality Improvement Plan (WQIP), analyzes phosphorus sources and quantities, and outlines practical steps that local agencies, landowners, and community stakeholders can take to reduce nutrient pollution. The goal is to restore the lake for safe and enjoyable use by the public and support healthy aquatic life.
Originally published on May 1, 2025, the WQIP underwent corrections during the final review by the U.S. Environmental Protection Agency (EPA), prompting a new round of public comment.
The video presentation is available at youtube.com/iowadnr and the full plan can be downloaded from the Iowa DNR website at:
🔗 www.iowadnr.gov/wq-improvement-plans