Flash Flood — Fremont, Colorado

2006-07-05 · near Penrose, Fremont, Colorado

Event narrative

Four to 6 inches of rain fell in approximately 2 hours on already saturated ground and caused significant flash flooding over a part of eastern Fremont county. The drainage basins of Beaver, Brush Hollow and Eightmile Creeks were overwhelmed, while several roads (County Roads 123 and 132, Phantom Canyon Road, State Highway 115) and bridges were washed out or damaged. Brush Hollow Creek was particularly destructive, overwhelming the culvert at State Highway 115 between Penrose and Florence. For a time, the fast flowing water was over 200 yards wide across the road. That portion of Highway 115 over the culvert was completely destroyed and remained closed for six weeks. County Road 123 was severely damaged by Eightmile Creek. All the water from the Eightmile and Brush Hollow drainage basins emptied into the Arkansas River upstream from the Portland River gage. The resulting river rise was extraordinary, in fact, a record crest for that part of the Arkansas River...13 feet. The gage's instruments were completely submerged, for a time, and debris nearly destroyed the gage. Severe flooding occurred on Beaver Creek, which empties into the Arkansas River downstream of the Portland gage. A paleo-hydrologist with the USGS in Denver estimated that Beaver Creek went from a trickle to about 13 feet in less than 15 minutes...a true "wall of water" flash flood.

Source: NOAA Storm Events Database, event_id 5522081. Narrative written by the NWS forecast office that issued the report.