1. The Effects of Snowmelt in the Roaring Fork Valley near Aspen, Colorado Christina Stanard Surface Water Hydrology April 24, 2007

2. Outline Background – Roaring Fork WatershedBackground – Roaring Fork Watershed Problem – FloodingProblem – Flooding Analysis – Data, Graphs, HistoryAnalysis – Data, Graphs, History Future Work – CorrelationsFuture Work – Correlations

3. Colorado Roaring Fork Watershed ROCKY MOUNTAINS Denver Aspen

4. Roaring Fork Watershed Known for... –Skiing –Trout fishing –Beautiful scenery –Being expensive! Fishing on the Frying Pan River$135 Million, Most Expensive Home in the U.S., Aspen, CO

5. Roaring Fork Watershed

6. Basalt, CO Confluence of Frying Pan and Roaring Fork Rivers Rapid growth led to development on flood plain Pitkin County press release in May 2006: “Higher than average snow pack this past winter has emergency management officials... prepared for possible flooding this runoff season. Officials have been closely monitoring water levels, snowmelt and weather, standing at the ready for possible evacuations and sandbagging if warm, wet weather should combine with snowmelt causing area creeks and rivers to overflow in the peak weeks to come.” www.aspenpitkin.com www.aspenpitkin.com Flood mitigation projects

7. Basalt, CO Fryingpan River Roaring Fork River

8. FEMA Map for Basalt, CO Gold Rivers Apts.

9. Ruedi Reservoir

10. Analysis – Data Sources USGS Gages: Streamflow –09080400 FRYINGPAN RIVER NEAR RUEDI, CO. –09073400 ROARING FORK RIVER NEAR ASPEN, CO. NCDC: Rainfall and Snowfall –050372 ASPEN 1 SW –055507 MEREDITH Ruedi Reservoir: Levels, Inflows and Discharges –Bureau of Reclamation

11. Roaring Fork Watershed FRYING PAN RIVER NEAR RUEDI, CO. ROARING FORK RIVER NEAR ASPEN, CO. MEREDITH ASPEN 1 SW

12. USGS Station 09080400 – FRYING PAN RIVER NEAR RUEDI, CO. March 30, 2007 Stage = 1.7’

13. Precipitation vs. Streamflow Aspen

14. Flood History Research –June 1921 “used as a reference when comparing historical flood magnitudes in Colorado” –June 1957 –May and June 1984 Extensive damage, all time peak discharges NCDC “Storm Events” FLOOD events reported in Pitkin County, Colorado between 01/01/1995 and 12/31/2006:

15. Snowpack History NRCS Colorado Snow Survey

16. Future Work Snowfall data to Snow-Water-Equivalent Snowfall data to Snow-Water-Equivalent Reservoir data analysis Reservoir data analysis Further correlate the relationships to Further correlate the relationships to predict flooding predict flooding

17. Questions?