Flood in Granite County, Montana

Granite county saw widespread impacts from the heavy rain. Philipsburg, MT received 3.28 inches of rain in 24 hours from noon 6/12 through noon 6/13. A public report from Georgetown Lake, MT had a measured 3.7 inches of rain over the 2-day event. Fred Burr Creek was particularly hard hit, with private driveway bridges being washed out, thus stranding a couple residents. Many of these same residents had basement flooding as well. USGS stream gauges on Boulder Creek near Maxville recorded 1410 cfs; 1000 cfs begins to cause road flooding issues, and this was much above this impact level. Rock Creek and Flint Creek both saw extremely rapid and high flows, with water spilling into adjacent fields. Georgetown Lake over-topped its spillway for the first time in years. Sapphire Mountain ditch managers narrowly avoided damage to a major irrigation channel feeding the Bitterroot Valley.

A closed low pressure system brought widespread heavy precipitation amounts of 1-3' across portions of western Montana. The combination of heavy rain and continued high elevation snow melt caused rapid rises on small streams and creeks, especially around Georgetown Lake, Philipsburg, Drummond, and the Sapphire Mountains.