Flood in Clearwater County, Idaho

The most significant impact occurred south of Orofino, where a large landslide blocked US-12 between mile markers 44 and 45. The initial slide occurred around 1539MST on Friday, March 13. While crews worked to clear the route, a second slide occurred at the same location at 0920MST on Saturday, March 14. The highway remained closed in both directions until Saturday afternoon. Additional landslides and rockslides were reported on Lower Fords Creek Road, Grangemont Road, Sunnyside, and Bobbitt Bench. Heavy traffic diverted to Sunnyside Road caused that secondary route to begin failing under the saturated conditions.

In Orofino, the urban drainage system reached maximum capacity and overflowed, flooding residential areas. In the Riverside area (115th Street), rushing water surrounded homes and filled basements. Significant damage occurred at the Joint School District 171 bus garage when a nearby creek (likely Flume Creek) blew out, flooding the facility. While officials successfully moved most of the fleet, one school bus and a neighboring food pantry were inundated and suffered major damage.

Small streams and creeks, including Jim Fords Creek and Freeman Creek, crested their banks, threatening homes and washing out culverts. Near Weippe, a creek overflowed onto the roadway, causing significant rutting. The Clearwater River at Orofino saw a dramatic rise of over 8 feet, increasing from 5.78 feet on Thursday to a crest of 13.96 feet on Saturday night'staying just below the 16-foot flood stage, though the high water contributed to the drainage backup in the city. Total rainfall between March 10 and 15 included 3.57 in Orofino, 4.00 in Peck, and 4.50 at the Pierce SNOTEL.

An intense and prolonged atmospheric river (AR) impacted the Northern Rockies, directed primarily at North-Central Idaho. This event was characterized by a deep moisture plume and an unseasonably warm air mass, which transitioned mountain snow to a heavy rain-on-snow event. Total precipitation across the Clearwater Basin ranged from 2.5 to over 5.0 inches. Impacts from this storm included power outages and impacts to travel. The biggest impact, however, was flooding in Clearwater County near Orofino. By the morning of March 13, several days of moderate rain and mild temperatures had completely saturated the soil. With the ground unable to absorb any more water and temperatures remaining above freezing overnight, continued rainfall and rapid snowmelt triggered immediate runoff. This surge of water overwhelmed culverts, destabilized hillsides, and caused rapid rises on small streams and the Clearwater River.