COLORADO — South Platte River near Lake George, Colorado, flows freely again following the recent removal of the Lake George Diversion Dam. The obsolete low-head diversion dam was located on the upper South Platte River in the South Park Ranger District. At the end of April, a cadre of scientists visited the project site to continue monitoring efforts that began before the dam’s removal. The team, led by Research Geomorphologist Charlie Shobe and Ecologist George Valentine, both from Rocky Mountain Research Station, included members from the Pike-San Isabel National Forests & Cimarron and Comanche National Grasslands as well as the University of Colorado Boulder. The project is part of the Collaborative Aquatic Landscape Restoration Program under the Bipartisan Infrastructure Law.

RMRS researchers used GPS to survey the shape of the river channel and collected sediment samples to determine the quality of habitat on the riverbed. This research will help scientists understand how river shape and aquatic ecosystem composition change after dam removal in steep mountain rivers. Monitoring will continue through at least 2025.

Before its removal, the low-head diversion structure impeded the natural movement of sediment, which modified the structure of the floodplain and channel, negatively affecting fish habitat and jeopardizing fish reproduction and survival. Removal of the dam restores a popular sport fishing segment on the river to a more natural condition and improves local aquatic habitat and water quality of approximately 45 river miles of the South Platte River.

The removal, restoration and monitoring are a collaborative effort among the Rocky Mountain Research Station, the Pike-San Isabel National Forests & Cimarron and Comanche National Grasslands, the Coalition for the Upper South Platte, Colorado Parks and Wildlife, Colorado Department of Water Resources, the South Platte Enhancement Board, Park County and its Land and Water Trust Fund, Trout Unlimited, Denver Water, Aurora Water, and Colorado Springs Utilities.

Follow the link to learn more about Lake George Diversion Dam removal and stream restoration on the upper South Platte River.