Flooding
The Snoqualmie River is prone to flooding and typically sees multiple flood events annually that inundate local farmland and close low-lying roads. During record level floods, all road access to the towns of Carnation and Duvall becomes closed off. The last three times this happened were during the floods of 2009, 2006, and 1990.
The river level of the Snoqualmie River is monitored by six NOAA flood gauges, one on each fork, one just above the falls, one below Carnation, and one near Duvall. The Tolt River and the Raging River are also monitored by flood gauges.
The Snoqualmie Flood Reduction Project was a controversial Army Corps of Engineers project completed in 2005 to reduce the effect of floods in the town of Snoqualmie by widening the river just above the falls.
Read more about this topic: Snoqualmie River