Polk County Conservation outlines Fourmile Creek Greenway restoration, buyouts and trail plans

Polk County Conservation staff presented an update on the Fourmile Creek Greenway, describing long-term buyouts, restoration work and next steps for trail connections and neighborhood access. The presenter said the Fourmile Creek watershed "starts up in Slater and runs all the way down through Des Moines and down to the Des Moines River," serves about 80,000 people and encompasses roughly 76,000 acres.

The agency framed the work as a response to repeated flooding, including a major June 30, 2018 event that the presenter called "the highest crest on record, so it's about 17.5 feet." Since 1993, the city and county have used federal, state and local funding to offer buyouts; the presenter said "about 300 plus residential and commercial structures have been bought out since 1993." Polk County Conservation now manages roughly 800 acres of the Greenway and said the goal is to acquire properties within the 500-year floodplain to allow more natural, managed flooding.

Restoration work described included stormwater wetlands, mitigation banking and stream-bank and oxbow restorations. The presenter highlighted Trails End Wildlife Area as a mitigation-bank project with six wetland basins that "provides 330 acre-feet of flood storage." Staff reported about 8,000 feet of stream-bank restoration completed and plans for roughly 20,000 more feet, more than 150 acres of forest improvement and about 35 acres of prairie restoration along Jefferson and Mattern.

The presentation outlined a two-phase road-removal plan to retire unneeded streets left after buyouts while preserving pedestrian access where neighbors use roads for walking. The presenter said some roads will be partially removed to create looped soft and hard-surface trail options and noted that 4 Mile Drive has already been partially removed and will ultimately connect to the Gailey Wilson Trail.

Recreation improvements include a mountain-bike park north of Copper Creek Lake that is under construction; the presenter said the park and parking are expected to open in spring 2025 and that the final restroom siting remains under discussion because of floodplain constraints. The presenter also described ongoing challenges on some private parcels, including encroachment and debris, and said City of Des Moines Public Works helps with cleanup and maintenance of remaining streets.

Council members and attendees praised the conservation work and asked operational questions about remaining acquisitions and park facilities. An attendee praised staff and Amanda Rich, and the presenter said staff are coordinating with City of Des Moines real estate to approach remaining owners; the council was told the city budgets roughly $400,000 a year for acquisition and can acquire three to four properties annually at that rate.

Polk County Conservation staff listed acquisition priorities on maps and said some parcels present access or cleanup complications that may affect buyout timing. The agency asked for continued council support as it advances restoration, acquisition and trail-connection work.

The meeting then moved to the Development Services Department's presentation on tax abatement and housing policy.