Flash floods pose dangers for many towns and cities in Colorado. The following text is a hypothetical scenario of a flash flood in Manitou Springs. This scenario was derived from the Manitou Springs Flood Hazard Mitigation Plan (1985), written by geography Professor Eve Gruntfest, University of Colorado at Colorado Springs.SCENARIO
The day of the scenario is typical for the Colorado Front Range. The weather forecast calls for a chance of afternoon thunderstorms. An accumulation of cumulonimbus clouds over Manitou Springs and the entire Pikes Peak Region is not sufficient cause for alarm to the residents and tourists of Manitou Springs on this warm, summer afternoon.
At 3:30 p.m., the sky has blackened and rain is beginning to fall in the mountains.
By 4:20 p.m., the satellite detection system has alerted the National Weather Service Office in Pueblo, Colorado of the situation. They issue a flash flood watch for all of El Paso County. They contact the El Paso Office of Emergency Management, which in turn contacts the area's police and fire departments including Manitou Springs.
By 4:25 p.m., the local stations relay the flash flood watch to the broadcast region.
By 4:30 p.m., the storm has unleashed its full fury over the Fountain and Ruxton Creek drainage basins. The heavy rain causes many picnickers and campers in higher elevations to seek shelter or head for home.
By 4:50 p.m., the Alert System - an integrated network of stream gages and rain gauges in the drainage basin - is reporting heavy rainfall to the El Paso County Office of Emergency Management. Unfortunately, some of the gauges are not reporting because of loss of communications.
By 5:00 p.m., the thunderstorm has intensified and shows no sign of moving out of the area. The town of Cascade reports three inches of rain in the last half-hour. Flooding is beginning to occur on the east side of Manitou Springs.
By 5:10 p.m., the Office of Emergency Management calls the Manitou Springs Police Department to start to evacuate the people in the low-lying areas near Fountain Creek.
By 5:25 p.m., the National Weather Service in Pueblo issues a flash flood warning.
The alarms (Fig. 1) sound across the city of Manitou Springs alerting those who know that it is time to get to higher ground.
The police department sends out two police cars to warn people of the impending flood of Fountain Creek.
The sky over Manitou Springs has become incredibly black, interrupted only by sudden flashes of lighting. The intense rainfall is causing numerous rock and mud slides along the canyon walls and highway, trapping those people trying to escape by car. Flooding has already cut off the upper junction of Highway 24 and Manitou Avenue. Several cars (Fig. 2) are floating along the roads in low-lying areas.Please continue to page 2.