Fountain Creek Restoration at Riverside | Fountain, CO
CLIENT: El Paso County Department of Public Works
PROJECT TYPE: Stream Restoration
PROJECT LOCATION: Fountain, Colorado
WaterVation was hired by El Paso County Department of Public Works to develop stream restoration design plans for 0.48 miles of Fountain Creek through the City of Fountain and the Christian Open Space Conservation Easement. Fountain Creek, through the project area, is laterally constrained by development to the north and the highway to the south giving the creek no room to adjust to changing watershed conditions. Compounding this issue is that baseflows within Fountain Creek have significantly increased over the past decade which has caused vertical degradation in this section of Fountain Creek and caused two 30-foot high-terrace bank failures. This vertical degradation has resulted in the floodplain becoming disconnected which is starting to cause die-off in the adjacent old-growth cottonwood forests, which the Colorado Natural Heritage Program has listed as Rare and Imperiled Natural Communities with a global rank of G2/G3 and State rank of S1. The project site is devoid of fish habitat and contains two head-cuts which are currently fish barriers.
WaterVation developed stream restoration plans based on natural channel design principals to realign and restore the stable channel dimension, pattern, and profile through the project area along with reconnecting the adjacent floodplain to save the old-growth cottonwood forests. Detailed stream assessments were performed to collect geomorphic, ecologic, and biologic data for both the project reach and a reference reach just upstream of the project area. The reference reach data was used to design fish habitat features, the revegetation plan, and used as a starting point to design the proposed channel dimension, pattern, and profile. The proposed channel morphology was further refined using sediment transport models to evaluate sediment competence and capacity. Both one-dimensional and two-dimensional hydraulic models were used to evaluate shear stress and stream power for a range of flood events to ensure the proposed design provided adequate stability for the system during extreme hydraulic conditions.
Fountain Creek is a highly mobile stream system comprised of large sand and small gravel which makes controlling bedform very challenging. As a result, the use of in-stream structures was generally avoided. Toe wood was used to stabilize channel banks and willow staking and cottonwood poles were used to provide long-term floodplain stability. Riffle structures were designed using the native alluvium and shaped to provide bedform diversity to allow for fish passage where barriers currently exist. Long-term degradation protection was provided by burying boulders below the channel invert to the level of potential degradation.
Services; Stream Assessments, River Restoration, Natural Channel Design, Flood Control Design, Permitting, Construction Oversight
