Bohn Park in Lyons, Colorado was devastated by the 2013 Flood. Record rainfall in the North St. Vrain Creek watershed caused the creek to overtop its banks and inundate Bohn Park. Almost all of the park’s amenities and infrastructure were damaged or completely destroyed.
Scott Shipley, Birch Ecology’s Co-Founder and the President of S2O Design – along with S2O’s engineers and planners – were part of the team selected to redesign and restore Bohn Park after the 2013 Flood. As a part of this project, S2O was tasked with restoring the channel and floodplain of North St. Vrain Creek. The project included extensive modeling and the design of overflow channels to increase flood capacity and control future flood events.
A variety of creek stabilization and habitat structures were also designed and installed along the project reach. The creek reaches a maximum slope of 3% through the park. In order to mediate the steep slope and respect the public’s desire to maintain the natural appearance of the park, S2O designed several boulder cross vane structures and created a series of pools and riffles. To provide habitat for aquatic species throughout the year, the restored stream was designed with deep pools, wetland areas, and proper structure and boulder placement.
On average, Bohn Park hosts 200 to 400 residents and visitors every weekend. Therefore, balancing recreational creek access with protection of the riparian corridor was a critical issue for project design. The design included strategically placed, hardened river access points that allow users to access the river for fishing and active creek recreation, while protecting the stream banks from erosion. Fencing, signage, and elevated boardwalks were also used to protect riparian wetland habitats in the restoration area of North Saint Vrain Creek. S2O completed the hydraulic modeling necessary to design and locate the boardwalk structures and pedestrian bridge.
- Extensive public outreach and public participation throughout the design process.
- Design of three boulder cross vane structures and a series of defined pools and riffles.
- Design and placement of habitat structures including: habitat boulders, rootwads, and a toe wood structure.
- Detailed 2D hydraulic modeling of the park area that led to the design of two overflow channels to reduce the impact of future flood events.
Project Construction Cost: $1.2 million (Creek Portion) $4.1 million (Entire Park)
Key Staff: Scott Shipley, Nathan Werner, Christine Clark
Project Dates: May 2016- May 2017