Flood — Ferry, Washington

2017-04-01 to 2017-04-28 · near Keller, Ferry, Washington

Event narrative

Ferry County was affected by numerous road washouts due to areal flooding and debris flows during much of the month of April. Travel was disrupted through out the county with at least 20 roads closed or reduced to one lane due to damage.

The most notable road closures include Highway 395 near Boyds, which suffered a 100 foot section of the road washed away into a 20 foot deep chasm on April 13th, and Highway 21 where a temporary one lane bridge was constructed to cross a 100 foot total washout of the road 15 miles south of Republic, and the Inchelium Highway near Inchelium where a debris flow cut the road on April 15th. All of these roads are major north-south highways through the county.

The Sanpoil River flooded during this period causing one house to wash away into the river and threatened another home as the flood undermined the bluff it was located on.

Wider weather episode

In addition to a wet March, periodic heavy rains continued during the month of April. In Ferry County, the COOP station at Republic recorded 2.93 inches of rain for the month, which is 1.42 inches above average. In Okanogan County the Omak ASOS station recorded 2.66 inches of rain, which is 1.62 inches above average. At Mazama the COOP observer recorded 2.45 inches of precipitation, which is 1.42 inches above average.

All of this rain on top of spring time snow melt promoted saturated soil conditions which resulted in numerous debris flows and areal and small stream flooding issues through out Ferry and Okanogan Counties during the month of April.

Ferry County had been experiencing these issues through the end of March but more rain in April aggravated the situation resulting in major debris flows and flooding which cut key roads through the county. The Sanpoil River also flooded to levels which a media statement issued by the Ferry County Sheriff's Office and the Colville Tribal Police described as the worst flooding in decades.

Okanogan County largely escaped problems during the month of March but April brought the axis of periodic heavy rain storms and accelerated low elevation snow melt to this county. Saturated soil conditions, often over extensive recent burn scars, resulted in numerous debris flows and small stream floods which disrupted travel for much of the month and isolated a few back country residents for long periods of time. Highway 20, one of the major roads through the region remained closed over Loup Loup Pass while major repair work continued into the month of May.

View location on OpenStreetMap → (47.8467, -118.3887)

Source: NOAA Storm Events Database, event_id 693056. Narrative written by the NWS forecast office that issued the report.