OSO, Wash – Water began to breach the mud and debris dam choking the north fork of the Stillaguamish River just before 1:00p.m. Sunday afternoon.
Snohomish County officials called the breach ‘slight’ and said it was occurring on the north side. Officials hope such a breach would begin to allow a gradual release of the water upstream.
Others at the scene reported seeing some water beginning to overflow the debris.
Water had been backing up behind that natural dam which formed after the slide which occurred Saturday morning around 11:00 a.m.
The National Weather Service issued a flash flood warning Saturday for communities in the downstream flood plain, but downplayed the chance of large scale flooding.
“[The] latest models say flow won’t be catastrophic,” tweeted the officials Snohomish County Twitter account.
Snohomish County emergency crews lifted an evacuation order for residents along the river as far downstream as Stanwood after initially asking those folks to leave overnight. But authorities cautioned the order could be reinstated at any moment depending on what happened at the slide area.