FLOOD10215 - Laserfiche WebLink

Home Browse Search

Flood HvdroloE!V Although the snowpack produced by the winter and spring weather of 1994-1995 was very high, most of the snowmelt flooding that followed was not record flooding. Most snowmelt flood peaks fell between a 10-year and a 50-year frequency. On the Crystal River and on the Upper Arkansas River, frequencies were estimated at the 100-year level, but elsewhere the flows were smaller, relatively speaking. Because the heat wave in mid-June was stopped by record cold on June 17, the rate of melting (when there was still a lot of snow in the watersheds) dropped substantially. When the heat returned in early to mid-July, there was too little snow to sustain a heavy runoff except in a few locations. . Rain-induced floods were in the range ofa IO-year to a 25-year frequency. Most rainfall amounts were about 2-3 inches, which is not record-breaking. There were some instances of larger rainfall amounts, but there were no rainfall floods of a 100-year or greater frequency_ The Board constructed river forecast models for ten river stations. These model were used to predict the approximate date of peak flooding and to estimate the peak flood discharge. These models were useful tools for flood forecasting and for flood damage prevention. Using past high runoff years as a guide, the models tracked snowpack, temperatures and streamflow for the ten stations on a daily basis starting on May 15, 1995. At the June 12, 1995 meeting of the Task force the models predicted flood peaks for the week of June 12-18, and over that weekend most streams did experience their 1995 snowmelt peak. STREAMlLOCA TION Cache la Poudre River al Fort Collins Arkansas River at Wellsville Roaring Fork al Glenwood Springs Animas River at Durango Gunnison River at Gunnison N. Fk. Gunnison River al Sommerset Dolores River at Dolores Rio Grande al Del Norte Clear Creek at Lawson South Plane River near Kersey Colorado River at Stateline Gunnison River at Delta Yampa River al Sleamboat Springs SUMMARY OF FLOOD EVENTS FORECASTED FLOW FLOW 6,000 cfs 6,000 cfs 13,000 cfs 9,000 cfs 6,500 cfs 9,000 cfs 5,000 cfs 8,000 cfs 1,500 cfs 17,000 cfs 50,000 cfs 16,000 cfs 5,000 cfs 5,240 cfs 5.490 cfs 12,100 cfs 7,290 cfs 7.560 cfs 7,460 cfs 4,730 cfs 7,670 cfs 1,700 cfs 21,000 cfs 49,500 cfs 15,100 cfs 3,710 cfs ACTUAL DATE June 16 . June 23 June 17-18 June 16 & 18 June 18 June 15 June 18 June 18 June 17 June 1 June 19 June 14 June 17