IDALS KOS953027D - Whittemore, IA

ISG designed a one-of-a-kind tiered pond wetland system to manage tile drainage runoff from 633 acres in Kossuth County. The landowner initially sought a reservoir wetland to capture water for irrigation, but ISG, partnering with the Iowa Department of Agriculture and Land Stewardship (IDALS), developed a solution combining storage with a pumped wetland basin for continuous water treatment. This approach overcame difficult site constraints, including variable soils, established agricultural infrastructure, and existing tile mains, while creating a system that could store and recycle water for irrigation and reduce nutrient loads before discharging into the Drainage Ditch No. 9 Lateral 6 open ditch.

Adding wetland functions to a traditional reservoir allows the tiered wetland design to treat more water at a steady flow, reducing nitrates without added cost. The site was designed to allow for Iowa State University to monitor water quality and flow volumes, informing future research of drainage water recycling’s quantifiable water quality outcomes.

This project serves the future of water management in Iowa, directly supporting the state’s Nutrient Reduction Strategy by pairing agricultural productivity with downstream water quality benefits. By meeting landowner irrigation needs and public water quality goals, ISG delivered a first-of-its-kind solution that is expected to shape how similar projects are designed across the Midwest.