DENVER– Wednesday is all about flood safety as part of the severe weather awareness week.
Flooding can be a big problem in Colorado as evidenced in September 2013.
Starting September 10, 2013, the 1 in a 1000 year flood began with an inch of rain falling in Boulder. The next day had another inch, and the rain continued to come down for several more days.
After a week, weather stations across northern Colorado recorded as much as 20 inches (in some cases more) in total precipitation.
All the water ended up in the South Platte River, with major river flooding occurring from Boulder, Longmont, Lyons and Greeley to the state line and into Nebraska.
River flooding can result from heavy rain during the summer, rapid snow melt, or thunderstorm rains combining with runoff from melting snow.
Flash flooding refers to the dangerous sudden rise in water in a canyon along a creek or wash, or over normally dry land.
Flash floods result from heavy rainfall, sudden breaks in river ice jams and dam or levee failures. Flash floods can occur within a few minutes or hours and can move at surprisingly high speeds, striking with little warning.
Flash floods are quite destructive because of the force of the moving water, and the debris that accumulates in flood waters, such as trees and boulders, which can destroy roadways, bridges, and buildings.
Another complication in Colorado is the serious flooding that can result when heavy rain falls on recently burned areas.
The National Weather Service will discuss flood and flash flood potential in daily hazardous weather outlooks and in the weather story on National Weather Service websites.
A flash flood or flood watch, which means flash flooding or flooding is possible within the watch area.
A flood warning, which means flooding is imminent or has been reported along a river.
A flash flood warning, which means flash flooding has been reported or is imminent. When a flash flood warning is issued for your area, act quickly. If advised to evacuate, do so immediately. Go to higher ground or climb to safety before access is cut off by flood waters.
Nearly half of all flash flood fatalities are vehicle-related. Do not enter a flooded roadway. Instead, ‘turn around …do not drown’.
In rapidly rising waters, backing up away from water may be safer. One to 2 feet of water will carry away most vehicles and you also cannot tell if the road is damaged beneath the water.