The Walnut Creek Watershed is located in west central Iowa and encompasses 53,697 acres located in both Dallas and Polk counties. Around sixty percent of the watershed is rural/agriculture and forty percent is urban. The agriculture portion is mainly located in the northern portion of the watershed and includes the communities of Dallas Center and Grimes. The urban portion, located in the southern half of the watershed, includes the communities of Clive, Waukee, West Des Moines, Windsor Heights, Urbandale, and Des Moines.
Walnut Creek and its tributaries extend 97 miles before joining with the Raccoon River in the southeastern corner of the watershed. The confluence with the Raccoon River occurs just above the Des Moines Water Works treatment facility. This facility provides clean drinking water to the residents in the metro area.
High levels of nitrates, bacteria, and increased flooding are the main concerns within the Walnut Creek Watershed. A watershed management plan has been developed to address these concerns. This plan will provide guidance for overcoming these issues as well as others throughout the watershed.