Button Rock Restoration Project
North St. Vrain Creek, located in Boulder County, is approximately 32.2 miles long, and a tributary of the South Platte River. It drains part of the foothills north of Boulder and the Colorado Piedmont area in the vicinity of Longmont. The creek is formed by the confluence of North and South St. Vrain creeks at Lyons, Colorado.
Prior to restoration the City of Longmont experienced catastrophic flooding, especially along the St. Vrain Creek. This flooding affected many properties both within and outside the existing floodplain and damaged much of the city's infrastructure. Flooding of this magnitude had not been experienced in Longmont in nearly a half‐century. North St. Vrain creek through Button Rock Preserve was severely affected by the flooding event of September 2013. The river experienced substantial geomorphic changes including extensive scour, as well as the complete loss of the majority of the riparian corridor vegetation. Within Button Rock Preserve, the City of Longmont has partnered with Boulder County to restore a section of river at the entrance of the Preserve. The river restoration plan proposed restoration for an approximate 1.3 mile reach of North St. Vrain creek and creating two fish passages.
The City of Longmont has been awarded a grant from the Colorado Department of Local Affairs Community Development Block Grant – Disaster Recovery Watershed Resilience Pilot Program, which is designed to help watersheds recover from damage sustained in the flood events of 2012 and 2013. As a part of this effort, the Button Rock Restoration Project consisted of in‐stream channel restoration and riparian corridor restoration. The in‐ stream channel restoration practices include excavation and configuration of creek benthic material to create, enhance, and protect aquatic riffle, run, and pool habitat. Likewise, the riparian corridor required installing soil rip‐rap on the Longmont Dam Road embankments, creating planting islands along the embankments.
In future years, the restored portion of North St. Vrain creek will become an established low flow stream channel with benching practices that will be able to sustain high flow events, such as extreme flooding. The configuration of instream restoration will protect existing infrastructure, provision of drinking water, wildlife habitat, and recreational angling.
Construction of a rock vain along the North St. Vrain creek in Button Rock Reserve, CO.
Excavation of a low flow channel, bench construction, and habitat boulder placement.
Benthic excavation to create, enhance, and protect aquatic riffle, run and pool habitat.