Idaho, 1997

Flash Flood in Idaho, September 11, 1997

September 11, 1997 · NWS BOI · 1 event in 1 county or zone

1 flash flood, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
$60,000
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

The radar

The Boise radar (KCBX), 4 km away, was scanning. The volume nearest the first event began at 01:40 UTC.

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Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Ada

When
September 11, 6:40 PM MST to 8:00 PM MST
Where
Ada County, Boise
Property damage
$60,000
Coordinates
43.451, -116.241 (the zone’s center; the record gives no point)

During the evening of September 11, a flash flood occurred in the foothills of the Boise Mountains. The foothills had received significant rainfall all day long. Between 500 pm and 600 pm MST a heavy shower dumped 4 tenths of an inch of rain in 9 minutes on the foothills triggering flash flooding into the north end of Boise. The wall of mud and debris was estimated at 15 feet high as it breached six flood control dams and washed over a golf course. While most of the damage consisted of mud and debris on local roadways, the golf course sustained damage and 12 houses were slightly damaged at the foundations. No injuries were reported. As of publishing , damages to roads in the city and clean up costs were estimated at at least 60,000 dollars.

What these are

Flash Flood
Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Idaho in 1997Every state in 1997This day in weather historyWarnings in Idaho, September 1997

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5616835.