Fourmile Watershed Overview

The Fourmile Creek Watershed is 76,600-acres consisting of urban and agriculture communities. It is currently home to over 80,000 people. The watershed’s northernmost reaches begin near the town of Slater. The largest area of the watershed is located in Polk County and encompasses the cities of Sheldahl, Alleman, Elkhart, Ankeny, Bondurant, Altoona, Des Moines and Pleasant Hill.

Fourmile Creek and its tributaries run for over 40 miles before draining into the Des Moines River. Along its path, the creek has a long history of extreme flooding, erosion, and poor water quality. To address these diverse issues, local communities created one of the first watershed management authorities (WMA) in the state in 2012. This WMA focuses on collaborative work to address flooding and water quality.

Learn More

Learn what you can do to address the numerous issue of the Fourmile Creek Watershed, including water quality and flooding. To achieve the goals outline by the watershed management plan, we need collaboration from residents of urban and rural areas as well as policy makers.


Across the upper portion so the watershed rural landowners are working to install conservation practices that hold water upstream, improve water quality, and reduce downstream flooding. These practices may include bioreactors, cover crops, stream buffers, grassed waterways, and wetlands.


In urban areas we must work together to improve stormwater management to improve water quality, reduced runoff, and create more flood resilient communities. Developers, cities, and homeowners can create landscapes that treat rainfall as a resource rather than a waste product


Policy alterations can mitigate the impacts of urban development in the Fourmile Creek watershed. These changes include stream buffer requirements, floodplain protection, and Iowa Stormwater Management Manual design guidelines.

Watershed Stories

Below are some of our latest stories and projects.

9 different communities are located within the Fourmile Creek watershed