Year Established: 2017 Start Date: 2017-03-01 End Date: 2018-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $2,550
Principal Investigators: Sara Rathburn
Abstract: In September 2013, Colorado's Front Range was inundated by a storm that resulted in a 500-year flood on North St. Vrain Creek, which flows into the Ralph Price Reservoir that supplies >100,000 Colorado residents1,2. This single storm significantly impacted the reservoir, producing a 2-4% loss in storage capacity3. Additionally, the flood caused 10 meters of aggradation at the inlet, altering channel geometry and transforming the inlet into an approach channel3. As the aggraded channel adjusts towards a state of equilibrium, sediment continues to be remobilized and transported into the reservoir. Previous research on channel response to floods does not distinguish between adjustments after direct anthropogenic impacts versus those from extreme natural events. Largely unaffected by human activities, the North St. Vrain offers a rare opportunity to track changes in channel geometry following an extreme sedimentation event. My research will apply novel techniques of photogrammetry to obtain repeat, high-resolution topographic data of channel characteristics to better understand channel development in response to extreme events. These quantitative changes will be applied to a computational 2-d model to predict future channel morphology and sediment deposition into the reservoir. Analysis of sediment cores from the reservoir delta will refine the sediment transport model, confirm ongoing sedimentation rates, and enable prediction of future sediment deposition and reservoir storage capacity loss. Results from this work will provide invaluable information for water managers regarding channel adjustment and recovery of North St. Vrain Creek, as well as sediment transport and deposition into the reservoir to assist with future storage needs.