Jul 5, 2012
A slow moving thunderstorm brought heavy rain to the Four Mile Canyon burn area northwest of Boulder. The heavy rain triggered rock and mudslides along Fourmile Canyon Drive near Logan Mill, Nancy Mine and Gold Run Roads. In addition, Crisman Road and Wall Street were also closed until the debris could be removed. Nearly an inch of rainfall, 0.90 inches, fell in a 30 minute period.
Source: NOAA National Weather Service Storm Events Database (event 397931). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Boulder County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.