Water Quality Improvement Plan Addendums for Hickory Grove Lake and Otter Creek Lake Open for Review

DNR-News-Releases

Published March 26th, 2026

Detected March 26th, 2026

Summary

The Iowa DNR has released addendums to water quality improvement plans for Hickory Grove Lake and Otter Creek Lake for public review. These addendums explore the connection between phosphorus levels and new turbidity impairments, aiming to provide a comprehensive guide for improving lake water quality. Public comments are due by April 27, 2026.

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What changed

The Iowa Department of Natural Resources (DNR) is seeking public comment on addendums to existing water quality improvement plans for Hickory Grove Lake and Otter Creek Lake. These addendums address new impairments related to turbidity and connect them to previous studies on phosphorus levels, which were identified as the cause of high algae levels impacting recreation and aquatic life. The goal is to provide a more complete understanding for local agencies, partners, stakeholders, and residents to guide efforts in improving the lakes.

Interested parties can view a presentation on the Iowa DNR's YouTube channel until April 27, 2026. Full documents are available for download on the Iowa DNR website. Public comments must be submitted via email or mail by April 27, 2026. Following the comment period, the DNR will forward the addendums to the U.S. Environmental Protection Agency for approval.

What to do next

Review the addendums for Hickory Grove Lake and Otter Creek Lake.
Submit public comments by April 27, 2026.

Source document (simplified)

Water Quality Improvement Plan Addendums for Hickory Grove Lake and Otter Creek Lake available for public review

Thursday, March 26, 2026
Events & Public Meetings

DES MOINES – Iowans interested in the addendums to two DNR studies to improve water quality in Hickory Grove Lake in Story County and Otter Creek Lake in Tama County; can view a presentation on the Iowa DNR’s YouTube channel.

Hickory Grove Lake and Otter Creek Lake were previously listed on the state’s impaired waters list for high levels of algae. The DNR conducted studies in 2021 for Hickory Grove Lake and 2014 Otter Creek Lake. These studies showed how the respective problems were caused by too much phosphorus in the lake. The problems impact recreation on the lake and aquatic life.

Subsequent to the respective studies, Hickory Grove Lake and Otter Creek Lake were listed on the impaired waters list for turbidity issues. The addendums explore the relationship between these new impairments of turbidity and the previous studies focus on phosphorus and how they are connected. The addendums are designed to give a more complete story with relationship to listed impairments in order to better serve as a guide for local resource agencies, partners, stakeholders and residents to improve the lake.

The presentation is available now at youtube.com/iowadnr through April 27, 2026. The full documents can be downloaded on the Iowa DNR’s website at the following:

Hickory Grove Lake Addendum
- Hickory Grove Lake Water Quality Improvement Plan
Otter Creek Lake Addendum
- Otter Creek Lake Water Quality Improvement Plan The presentation is available now at youtube.com/iowadnr through June 30.

Public comments on the plans must be submitted by April 27, 2026 to the following:

E-mail: James.Hallmark@dnr.iowa.gov

Mail: Jim Hallmark, care of Iowa DNR, 6200 Park Ave, Suite 200,Des Moines, Iowa 50321

After gathering Iowans’ comments, the DNR will forward the addendums to the U.S. Environmental Protection Agency for approval.

*Free Language Assistance. If you speak a non-English language, we offer you language assistance services free of charge. Call (515) 725-8200.

Asistencia lingüística gratuita. Si habla un idioma que no sea el inglés, los servicios de asistencia lingüística están disponibles de forma gratuita. Llame al (515) 725-8200.