The St. Vrain Corridor Committee was formed in 1992 to address issues relating to stream flow in the North St. Vrain River. The Committee has representatives from Boulder County, Lyons, Longmont, Colorado Division of Wildlife, Colorado Water Conservation Board, Colorado Forest Service, Trout Unlimited and the District. The current leading issue of concern is increasing winter stream flow in the North St. Vrain between Button Rock Dam and Lyons to support recreation, fishing and tourism.
Trout are a native species in St. Vrain Creek in the reach between Lyons and Longmont, where the mountain creek makes its transition to a plains stream. A critical limiting factor for trout habitat in this reach is low winter streamflow. Ditch companies with headgates in this reach have water rights for storage that allow them to divert creek water during the winter to fill reservoirs. During periods of cold and dry weather when stream flow is diminished, these diversions for storage may dry up the creek just below their points of diversion, resulting in a streambed with stagnant pools and no flow.
A 1992 water leasing agreement between the St. Vrain Corridor Committee and the City of Longmont provides for the City to release water from Ralph Price Reservoir in Button Rock Preserve into North St. Vrain Creek to help maintain sufficient instream flow for trout. A way was needed, however, for these small instream flows to make it past the ditch headgates without being diverted. In order to provide the precision metering and control needed to separate the instream-flow releases from the legal diversions, in 2008 the Corridor Committee, working with the City of Longmont, Boulder County, and the St. Vrain & Left Hand Water Conservancy District, installed a special flume gate at the diversion point for the Oligarchy Ditch. The goal is to install two additional flume gates at two other key diversion points for storage decrees. The result is expected to restore sufficient winter instream flow to maintain the trout fishery.
In 2008 the District, City of Longmont, and Boulder County installed a special gate to regulate flows during critical low flow periods within St. Vrain Creek. The gates were installed on three diversion structures, the Rough & Ready, Oligarchy, and the Highland. The project was completed in partnership with Trout Unlimited. Unfortunately, all three Rubicon gates were heavily damaged or destroyed by the September 2013 Flood.