Replacing Hazardous Grade Control – How Whitewater Recreation Can Improve Natural Stream Function
Layton Bodkins, PE, CFM
Theresa Ring, PE, CFM
Merrick & Company
Denver, CO 80211
Bodkins, Layton, PE, CFM; Ring, Theresa, PE, CFM; Shea, Daniel C., PE
The Mile High Flood District and Adams County initiated the Clear Creek restoration project to remove an approximate 10-foot-high, 100-year-old hazardous drop structure located within the BNSF Railway Right-Of-Way. The Project’s primary objective was to address safety, floodplain, maintenance, and liability concerns surrounding the existing BNSF railroad bridge. The Project has expanded to now include transforming the site into a whitewater venue with urban stream restoration, stability improvements, and upland park improvements. This presentation will review the channel design which replaces the existing hazardous structure with a series of whitewater drop structures, including two (2) feature waves and six (6) recreational rapid drops.
This presentation will also emphasize opportunities for evolving a standard infrastructure project into a holistic, restorative, and community-focused project in an urban stream corridor using the crucial support of project champions and subject matter experts. In addition to the recreational grade control structures, the Clear Creek design team proposed a realignment within the 1,500 linear feet of channel improvements to enhance the stream function and provide more stable flow dynamics at its crossing with the railroad bridges. Additionally, the outfall of the adjacent “Little Dry Creek Lake” will be transformed from the existing piped connection into an open habitat channel with several vegetated benches, creating 550 linear feet of new natural earthen channel.
A key challenge of the project was removing the overly retentive hydraulic conditions at the existing drop structure to provide low-hazard and high-performance recreation for river users while meeting the railway’s infrastructure goals. Extensive 1D, 2D, and 3D hydraulic models were analyzed to support a low hazard design for the channel restoration and whitewater design. The Project was further challenged by the discovered presence of landfill debris with asbestos containing material over much of the areas near the river, resulting in the need for a materials management plan and disposal at an off-site, permitted landfill.
The audience will develop a greater understanding of how to identify opportunities for expanding standard infrastructure projects, such as a grade control structure replacement, into a multi-objective, restorative design for the community and natural environment.
About Layton Bodkins, PE, CFM Coming Soon
About Theresa Ring, PE, CFM
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