Cañon City, Colorado
The Cañon City River Whitewater Park was a transformational project. As has happened to so many river towns throughout the American west, the river had been channelized, armored, and dams had been created through the downtown area. The project was a revitalization of the river that recognized the river’s need to function in its natural manner, but also its value to the town as a recreational amenity and as the focal point of their City Park. S2O Design transformed the river from a concrete-lined channel to a stunning natural waterway with rounded granite boulders, natural rapids, kids access and play areas, and fully functional surfing and kayaking features throughout the park. The park also provides a kids fun play area.
The project had three overarching goals:
- Recreation Enhancement – Recreational improvements enhance the river experience for both city visitors and members of the local community. Instream enhancements will provide a dynamic experience for rafters, kayakers and tubers; creating a valuable city attraction. While riverbank enhancements such as a connected trail system and open plan areas provide a relaxing out of water river experience
- Beautification of the River Corridor – Following earlier construction work, large quantities of concrete rubble and debris were present throughout the proposed project area. Debris removal and restoring the area’s ecosystem will aid in creating a thriving natural river and visually appealing parkland for all public users.
- Habitat Restoration – As part of the proposed project work, instream developments provided valuable habitat for fisheries. Boulders tactfully installed as velocity barriers will aid in creation of fish habitat and holding areas, while riffles and pools along current seams provide ample habitat opportunities for fish stock. By creating a multistage channel with stepped banks, riparian vegetation can be restored, providing critical habitat for macro-invertebrates, further enhancing fish ecological benefits and angling opportunities through Cañon City. A fish passage design approach, in collaboration with a fish biologist, will set a new standard for fish passage in whitewater park structures.
Bohn Park was devastated by the 2013 Colorado Flood. Record rainfall in the North St. Vrain Creek topped its banks and decimated Bohn Park. Almost all of the park’s amenities and infrastructure were damaged or completely destroyed.
S2O Design was part of the team selected to redesign Bohn Park and was tasked with restoring the North St. Vrain Creek. The project included extensive modeling and the design of overflow channels to increase flood capacity and control future flood events. The design also included the implementation of a variety of creek stabilization and habitat structures within the project area. The creek is very steep, with a maximum slope of 3%. To mediate the steep slope and respect the public’s desire to keep the park looking natural, S2O Design designed several cross vane structures, as well as a series of pools and riffles to curtail the steep slope. Finally, the design included deep pools, wetland areas, and structure and boulder placement that provide habitat for aquatic species throughout the year.
Additionally, balancing recreational creek access and protection of the riparian habitat corridor was also a critical issue. On average, the park hosts 200 to 400 residents and visitors every weekend. The design addressed this issue by strategically placing hardened river access points allowing users to access the river for fishing and active creek recreation, and allowing riparian habitat areas to remain undisturbed and thriving.
The Arkansas River is the main recreational attraction in Cañon City. Locals and visitors are drawn to the river to walk, picnic, tube, and paddle. The lush riparian vegetation and deep blue water, contrasted against the arid landscape around it, creates a picturesque landscape.
S2O Design’s task was to study a three-reach section of the Arkansas River through Cañon City, and to plan and prioritize projects within each of the reaches. A master plan and report was created and used as a starting point for conceptualizing possible design solutions to enhance whitewater recreation, fish habitat, and stream beautification.
The project objectives focused on expanding the existing community riverside park; restoring the function and aesthetics of the river corridor; stabilizing the streambanks; and enhancing the venue for rafting, whitewater kayaking (slalom and freestyle), tubing, and other healthy, active, outdoor recreational activities.
In response to the catastrophic damage caused by flooding in 2013, S2o was part of a design-build team that aimed to complete infrastructure improvements to the stream, its banks, and the upland areas on the St. Vrain Creek through the Town of Lyons, Colorado.
The final flood recovery channel sought to return the flood affected areas to a natural, more resilient, and sustainable stream corridor. S2o was commissioned to engineer and restore the St. Vrain Creek to a healthy and a well defined multi-stage river channel, with natural sinuosity, gradient and character.
The South Saint Vrain Creek Watershed is one of the most important natural features in the Northern Front Range of Colorado. In September, 2013, a flood devastated the watershed, the infrastructure, and the communities along the Saint Vrain Creek and its tributaries.
The Watershed Master Plan was developed by S2o and Baker Engineering, among others. The goal of the project was to create a science-based, community oriented, stream master plan. The project was part of an initiative supported by the Colorado Water Conservation Board to approach river projects from a wholistic approach bearing in mind the morphology of the river, the role and importance of habitat to the entire ecosystem, and the needs of communities and private landowners in terms of land use, flood and debris risk, and all types of in-stream recreation.
The master plan included assessments to geomorphology, FEMA risk assessments, habitat needs, and other scientific inputs. The information was blended with community and public process inputs that considered land-use pre-flood, and proposed land-use post flood. The resulting study produced and prioritized projects that allowed for a resilient and healthy stream corridor, a healthy riparian zone, a vital ecosystem, and a thriving economy along the riverbanks that is founded on healthy, active, outdoor-living.
S2O Design provided design and construction management services for the emergency watershed protection project in Lyons, Colo. The project was sponsored by the Town of Lyons and funded by the Natural Resources Conservation Service (NRCS), Colorado Department of Emergency Management, and the property owners.
NRCS classified several sites along the St. Vrain River as exigent sites in need of immediate attention to prevent further, future damage to private properties. S2O Design provided designs to protect from flows up to a 25 year return flow for seven properties in Lyons. After the first runoff season, where flows peaked between a five and 10-year return flow, the streambank stabilizations performed as expected. This project was one of the first permanent flood recovery projects to be construction in Lyons.
To accomplish the project objectives, the design aimed to remove large, channel blocking flood debris and stabilizing streambanks with a combination of rock and bioengineering techniques. The rockwork was covered with topsoil and an erosion control blanket. The banks were seeded and trees and willow stakes were placed intermittently throughout the sites. The project includes approximately 450 feet of streambanks on seven private properties.
The Town of Eagle Visitors Center Boat Launch was constructed in the fall of 2015 to provided an alternative put-in/take-out to an existing boat launch downstream. The Eagle Visitors Center Boat Launch allows users to exit the river before a difficult Class IV rapid. S2o provided conceptual design, construction documents, and construction oversight for the Town of Eagle.
The project created an improved concrete boat launch at an existing unimproved takeout that enhanced ingress/egress through the creation of eddies and tie-off boulders for boat holding. The project also protected the designed improvements from erosion by guiding flows away from the river bank using boulder weirs. The design also excavated and hauled-off native bank and channel materials from the site to create a self-maintaining, sheltered cove. Prior to the completion of the project, all disturbed areas were reclaimed with biodegradable erosion control blanket and native turf grasses.
The Supply Irrigating Ditch Company diversion structure was a multipurpose project on the St. Vrain Creek. S2o Design was hired by the ditch company to design a diversion dam that maintained the ditch company’s decreed flow, facilitated fish passage, and created recreational amenities for other users on the St. Vrain Creek.
Historically, the structure was a barely noticeable, at-grade concrete dam. Flooding in September, 2013 caused significant erosion downstream of the structure, degrading the channel to the extent that a new at-grade diversion structure could not be built.
S2o Design used it’s creative innovation in multi-purpose river engineering to design a grouted rock ramp structure which ensured that the ditch company’s decreed flow was diverted to the headgates, and provided added benefits to the fish and the recreational users. The structure was designed to facilitate fish passage at a variety of flows. The structure included a low flow fish passage notch, as well as designed interstitial spaces. This was created by holding grout back from the surface of the rock on the low, medium and high flow tiers of the structure. The design of the structure also promoted recreation at the site; the hydraulic conditions across the grouted rock ramp and in the tail water pool were designed in the same manner as a whitewater park structure, thus allowing the water not diverted down the ditch inlet to be enjoyed by recreational users.