7 flood insurance claims·$16,934 paid·2 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Granite County, Montana. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
River flooding dominates Granite County, supported by 18 recorded flood events compared to 3 flash flood events over the last 30 years. Seasonal high-elevation snowmelt combined with heavy rain systems frequently drive these water level rises. For example, a cut-off low pressure system in June 2018 brought 1 to 3 inches of rain to the upper Clark Fork River Basin, causing significant stream and river rises alongside high elevation snowmelt. Similarly, widespread heavy precipitation and snowmelt in June 2017 caused rapid rises on small streams and creeks around Georgetown Lake, Philipsburg, Drummond, and the Sapphire Mountains. Monsoon moisture can also trigger localized issues, as seen when multicellular thunderstorms produced heavy rain and flash flooding near Drummond in August 2013.
National Flood Insurance Program claims data indicates that historical payouts and water depths remain low across various zones. Zone A recorded 3 claims with an average payout of $8,361 and an average recorded water depth of 1 inch. Zone X Unshaded recorded 2 claims with an average $0 payout and an average 1 inch of recorded water depth. Zone Unknown recorded 1 claim with an average $213 payout and an average 0 inches of recorded water depth, while Zone X Shaded recorded 1 claim with an average $0 payout and an average 0 inches of recorded water depth. Properties near rivers, streams, and lakes, particularly in areas like Zone A, should pay the closest attention to flood risks driven by seasonal snowmelt and heavy rainfall.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
In flood insurance claims here that reported a flood depth, the average was 1 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2011, with 1 claims and $12,415 paid, the year of Severe Storms and Flooding.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
2 NOAA storm reports from Granite County describe what happened, in the words of the forecasters who covered it. Read the Montana flood stories →
8 federal disaster declarations since 1981, 2 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Apr 4, 2011 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Southwestern Zone Two Fire Complex | Aug 5, 2000 |
| Wildfires | Jul 13, 2000 |
| Heavy Rains, Landslides & Flooding | Feb 24, 1986 |
| Severe Storms & Flooding | May 27, 1981 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
21 since 1996: 3 flash floods and 18 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Jun 20, 2018 | — |
| Flood | Jun 13, 2017 | $50,000 |
| Flash Flood | Aug 9, 2013 | $500 |
| Flash Flood | Aug 9, 2013 | $5,000 |
| Flood | Jun 7, 2011 | — |
| Flash Flood | Aug 5, 2010 | $1,000 |
| Flood | May 10, 2005 | — |
| Flood | Mar 13, 2003 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Jun 20, 2018. A cut-off low pressure system brought 1 to 3 inches of rain to the upper part of the Clark Fork River Basin resulting in significant stream and river rises. High elevation snow melt also added to the water flow issues.
Flood · Jun 13, 2017. 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.
Flash Flood · Aug 9, 2013. A wave of monsoon moisture tracked south to north across western Montana on August 9, 2013. Embedded multicellular thunderstorms produced very heavy rain with flash flooding reported near Drummond and gusty winds that brought tree damage to portions of the Bitterroot and Missoula Valleys.
Flood · Jun 7, 2011. A mid level circulation over southwest Montana brought widespread heavy rainfall. This same area received significant rainfall the week before. This rainfall in addition to a heavy snow pack had saturated the ground with streams and rivers running high.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Granite County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.