Siuslaw River near Mapleton, OR

The last 7 days and the forecast

NWS forecast issued Mon, Oct 12, 8:25 AM. Forecasts change as rain falls and as upstream water arrives.

Flood stages

What floods at each level

From the National Weather Service, highest first.

• 32.5 ftthe flow at this level is about 62,000 cfs and has a 1 percent chance of happening in a given year (aka 100-year flood).
• 30.6 ftthe flow at this level is about 56,000 cfs and has a 2 percent chance of happening in a given year (aka 50-year flood).
• 28 ftexpect major flooding along Riverview Avenue area and numerous homes and businesses in Mapleton. Flooding of roads adjacent to the Siuslaw River in the vicinity of Mapleton is likely. Flooding of Highways 126 and 36 will be significant.
• 26 ftthe flow at this level is 42,000 cfs and has a 10 percent chance of happening in a given year (aka 10-year flood).
• 25 ftexpect widespread flooding, including several homes and structures in low areas of Mapleton. Many sections of Highway 126 from Tiernan to Mapleton, along with Hwy 36 north of Mapleton begin to flood. Flooding may be exacerbated during high tide.
• 23.2 ftthe flow at this level is about 35,000 cfs and has a 20 percent chance of happening in a given year (aka 5-year flood).
• 22 ftexpect widespread flooding of low-lying land. Several homes and structures in low areas of Mapleton start to flood. Numerous rural roads along and near the Siuslaw River will likely be flooded, and water begins to cover the lower sections of Hwy 126 at this stage. Flooding may be exacerbated during high tide.
• 20 ftexpect water over East Mapleton Road. Flooding of some low-lying homes and structures begins. Flooding may be exacerbated by high tide.
• 19.1 ftThe flow at this level is about 24,600 cfs and has an annual chance of 50 percent (aka 2-year flood).
• 18 ftexpect minor flooding of low lying dairy land along with some structures right along the banks of the Siuslaw River in and near Mapleton.

Highest crests on record

1. 30.21 ft — February 7, 1996
2. 28.45 ft — January 21, 1972
3. 28.28 ft — January 16, 1974
4. 28.07 ft — January 19, 2012
5. 28 ft — December 16, 1964

Recent crests: 21.6 ft (December 19, 2025) · 18.87 ft (March 16, 2025) · 19.73 ft (April 8, 2019) · 22.36 ft (December 18, 2015) · 18.36 ft (December 7, 2015)

Up and down the river, and nearby

• Alsea River near Tidewater, OR
• Long Tom River near Noti, OR
• Willamette River at Harrisburg, OR
• McKenzie River above Coburg, OR
• Marys River near Philomath, OR
• Siletz River at Siletz, OR
• McKenzie River above Hayden Bridge at Springfield, OR
• Coast Fork Willamette River at Goshen, OR