FLOOD06398 - Laserfiche WebLink

Home Browse Search

.. Colorado Water Conservation Board Flood Control and Floodplain Management Section FLOODS IN COLORADO DURING 1990 compiled by Shaye K. McGann Without discrimination, floods occur in all parts of Colorado. The causes of nooding range from snowmelt, to localized intense thunderstorms, to gentle rains falling over a wide area lasting several days, to failure of man made structures, to ice jams. Between twenty and thirty large floods happen in Colorado every year. Everyone is vulnerable and the only deciding factor of who is involved is chance. Usually flood causes are seasonal. Beginning in early March to mid May, we find snowmelt is the primary cause of flooding. This year snowmelt did not playa big part in early season flooding, Rather the largest cause of flooding in 1990 was during the sUlllmer months, when thunderstorms, severe rain, and even hail are in season. We saw quite a few dramatic storms in July. Fairly severe flooding occurred in highway underpasses in Denver stalling and flooding cars. Most of these floods were the result of inader(lwte drainage facilities on the highways and roads. Flights at Stapleton International Airport were delayed several times during the thunderstorm seflson flS a result of hoth hemry rains and lighting storms moving over the Denver area. Late .July hrought severe thunder storms to Ordway where fln undersized culvert inlot undor a railroml emhflnkment hindered the drainage of storlll wator flooding tho town. Early August rains caused over $100,000 in damage at Brush when 4.25 inches of rain fell in 24 hours. Flooding in the town caused authorities to evacuate residents. Later in August rains caused a ditch in Weld County to burst and the runaway water flooded the town of Frederick. A forest fire in 1989 in the Boulder Creek Bflsin left fln area of the watershed with severely reduced vegetation. Heavy rains saturated the hurned area quickly and without vegetation to impede the excess water, large amounts of ground water flowed into Black Tiger Gulch flooding the gulch twice during the year. In September Georgetown was the site of a large mudslide that caused 1-70 to be temporarily closed. The flood season can be year round as 1990 proved to us. In late December, fln ice jam gave way in Snowmass Canyon sending a 4 foot high surge of ice through the town of Basalt. An average of 4 people die each year in floods; however, 1990 was a hetter than avorflgo year as no deaths occurred as a result of floods.