Apr 26, 2005
A rupture in a retaining wall of a wastewater storage lagoon led to a dam failure which sent 77 million gallons of wastewater onto highway 207 south-southwest of Hermiston, washing out part of the road, and depositing several feet of silt on the road. A resident across the highway ended up with four feet of mud surrounding his home. The flash flood also damaged lines in the Westland Irrigation District. The storage lagoon was at around half capacity at the time of the flood.
Source: NOAA National Weather Service Storm Events Database (event 5442767). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Umatilla County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.