The landscape of the 53,000-acre Walnut Creek Watershed flows from the farm fields east of Dallas Center into the growing residential neighborhoods and business districts of the Des Moines Metro.  Walnut Creek and its tributaries touch nine communities and two counties - Des Moines, Clive, Dallas Center, Grimes, Johnston, Urbandale, Waukee, West Des Moines, Windsor Heights, and portions of unincorporated Dallas and Polk Counties. Over half of the watershed is rural/agriculture, but with continued development, the balance between rural and urban is changing rapidly. 

Walnut Creek Watershed is one of the most critical watersheds in Iowa. After traversing 97 miles, Walnut Creek drains into the Raccoon River less than one mile upstream of the water intake to the Des Moines Water Works plant, a public water supply serving nearly one-half million residents in Dallas, Polk, and Warren Counties. Walnut Creek has become a priority watershed for local jurisdictions to take action to reduce flooding impacts and improve water quality.  

To learn more about Walnut Creek Watershed, check out the Walnut Creek Watershed Master Plan and visit


Floodplains are areas next to creeks, rivers, and ponds that are naturally flooded from time to time. Floodplains naturally serve many purposes including natural flood and erosion control, biologic resources and functions, and societal resources and functions. Floodplains are hydrologically important, environmentally sensitive, and ecologically productive. Floodplains provide,
  • Flood and Erosion Control. Floodplains hold water and reduce the speed of moving water, decrease peak flows, and keep sedimentation levels down. By helping control floodwaters, floodplains can reduce property damage and protect people.
  • Water Quality Maintenance. Floodplains act as filters for runoff and organic wastes by absorbing excess nutrients and pollutants before they reach our waterways.
  • Groundwater Recharge. Floodplains reduce the frequency and duration of low surface flows.
  • Biologically Diverse Ecosystems. Floodplains hold nutrient-rich sediment from floodwaters, which build habitat above and below ground for many species. Wetlands provide habitat for many plants, reptiles, amphibians, fish, birds, and mammals. For example, wetlands provide resting spots for migrating birds, as well as nesting sites.
  • Scientific Study and Outdoor Education. In addition to their environmental benefits, floodplains contain cultural resources like historic or archaeological sites. Floodplains can also function as outdoor classrooms for people of all ages.
  • Improved Quality of Life. Floodplains contain value-added assets for communities, like the Greenbelt Trail. Floodplains provide many recreational opportunities, such as bird watching, fishing, canoeing, and hiking.
The City of Clive strives to protect and restore natural floodplain functions to add value to our community.