Creek Corridor Reclamation Improvements
Grange Hall Creek, Northglenn, Colorado
The Grange Hall Creek corridor in Northglenn, Colorado, which had been severely eroded by the increased stormwater flows associated with urbanization, was completely reconstructed and transformed into a diverse and rich riparian corridor. The eroded creek, with cut banks exceeding 20 feet in height, was raised to eliminate eroded banks and allow creek flows to spread out over a larger floodplain, thereby reducing problematic and erosive flood depths and velocities. Sculpted concrete water falls (or drop structures), necessary to reduce the gradient of the channel and dissipate stream energy, were developed to blend with the surrounding high prairie landscape. The regraded banks were stabilized using bio-engineering (vegetative) techniques.
Wetland mitigation for a U.S. Army Corps of Engineers 404 permit was achieved using protected overbank wetland planting areas that flood during minor storms, yet were not susceptible to erosion during peak floods. Pedestrian/bike trails, pedestrian bridges and underpasses connect the corridor to a regional trail network along the South Platte River. The project received the 2002 Grand Award from the Colorado Association of Stormwater and Floodplain Managers (CASFM).
A Stream principal led design while with Wenk Associates.