Flash Flood — Boulder, Colorado

2021-07-30 · near Lafayette, Boulder, Colorado

$20K

Property damage

Event narrative

Heavy rain caused localized flash flooding in Erie. Standing water stranded vehicles at the Intersection of Highway 7 and Mountain View Blvd. A couple of basements also flooded.

Wider weather episode

Flash flooding occurred on Tonahutu Creek. Trees, mud and debris shut down Grand Lake's hydro plant. Approximately 50 downed trees piled up at the plant's head gate and ash and mud filled the ditch leading to another gate. Another flash flood impacted CO-125. Additional flash flooding occurred in the Calwood and Cameron Peak burn areas, where up to 2.5 inches of rain fell in one hour. In Erie, heavy rain anywhere from 3.5 to 4.5 inches, produced flash flooding. Several vehicles were stranded in intersections and had to be rescued. Severe thunderstorms also produced hail up to quarter size in Larimer County.

View location on OpenStreetMap → (39.9800, -105.0700)

Source: NOAA Storm Events Database, event_id 975300. Narrative written by the NWS forecast office that issued the report.