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Storm hazard · NOAA Storm Events Database

Debris Flow in the United States

National statistics for debris flow events from the NOAA Storm Events Database (2015–2025): how often they occur, where they hit hardest, and the human and property toll.

1,942
Events recorded
68
Fatalities
$1.0B
Property damage
31
States affected

How dangerous are Debris Flow events in the U.S.?

NOAA's Storm Events Database has catalogued 1,942 debris flow events across 31 states and territories between 2015 and 2025. The cumulative human toll is 68 fatalities and 187 injuries, and the financial footprint reaches $1.0B in combined property ($1.0B) and crop ($34.3K) damage. On a per-fatality basis this places debris flow events at a high severity tier relative to other tracked hazard types in the NOAA catalog.

Geographic exposure skews toward a small cluster of frequently-hit states. The three states absorbing the largest share of events are CA (699 events, 30 fatalities), PR (395 events, 0 fatalities), CO (282 events, 0 fatalities), a mix of underlying hazard climatology and how many people live in the exposed corridor. At the other end, states such as MS, ME, WI report far fewer events, a meaningfully lower-frequency pattern there, though local vigilance still matters.

Annual totals swing noticeably from year to year. The peak year on record was 2022, logging 358 events and $19.5M in property damage in a single calendar year. The most recent year in the dataset is 2025 with 326 events recorded. Across the full 11-year window, annual event counts reflect seasonal climate cycles and, for some years, longer climate-driven shifts in frequency.

How to interpret this data

NOAA storm event data is filed by local National Weather Service forecast offices, so reporting intensity can vary by jurisdiction and should be interpreted alongside FEMA disaster declarations for a fuller picture.

For household and business preparedness, this state-and-year view should be paired with local-level FEMA National Risk Index ratings, flood-zone maps where applicable, and up-to-date NWS watch/warning information, population exposure and asset value matter as much as raw event frequency for estimating real-world risk.

Debris Flow by State

# State EventsFatalitiesProperty Damage
1 California CA 699 30 $663.0M
2 Puerto Rico PR 395 0 $7.2M
3 Colorado CO 282 0 $158.4M
4 Washington WA 85 0 $2.6M
5 Utah UT 75 0 $401.4K
6 Kentucky KY 54 0 $88.5K
7 Idaho ID 52 0 $6.5M
8 Nevada NV 48 0 $168.1K
9 New Mexico NM 32 6 $111.0M
10 Arizona AZ 28 0 $203.0K
11 Oregon OR 27 1 $253.0K
12 Virginia VA 27 0 $750.5K
13 West Virginia WV 24 1 $1.1M
14 Alaska AK 22 12 $35.3M
15 North Carolina NC 20 17 $2.6M
16 Hawaii HI 19 0 $3.9M
17 Montana MT 14 0 $158.0K
18 Tennessee TN 9 1 $26.4M
19 New York NY 7 0 $10.0K
20 Pennsylvania PA 4 0 $15.0K
21 Georgia GA 4 0 $210.0K
22 Wyoming WY 3 0 $0
23 Ohio OH 2 0 $0
24 U.S. Virgin Islands VI 2 0 $2.2K
25 Guam GU 2 0 $30.0K
26 Texas TX 1 0 $0
27 Vermont VT 1 0 $0
28 Massachusetts MA 1 0 $0
29 Mississippi MS 1 0 $25.0K
30 Maine ME 1 0 $350.0K
31 Wisconsin WI 1 0 $1.0K

Debris Flow by Year

Year Events Fatalities Injuries Property Damage
2025 326 6 4 $101.2M
2024 171 16 3 $16.2M
2023 165 6 4 $5.7M
2022 358 6 0 $19.5M
2021 212 2 2 $164.4M
2020 92 2 2 $34.0M
2019 185 2 1 $25.0M
2018 136 24 168 $619.8M
2017 191 0 0 $30.6M
2016 52 0 3 $618.0K
2015 54 4 0 $3.5M

Frequently Asked Questions

How many debris flow events have occurred in the US?
The NOAA Storm Events Database has recorded 1,942 debris flow events across 31 states from 2015 to 2025. These events caused 68 fatalities and 187 injuries.
Which states are most affected by debris flow events?
The states most affected by debris flow include CA (699 events), PR (395 events), CO (282 events). These three states account for a significant share of all recorded debris flow incidents in the US.
How much damage do debris flow events cause?
Debris Flow events have caused an estimated $1.0B in combined property and crop damage from 2015 to 2025. Property damage alone accounts for $1.0B, with crop damage at $34.3K.
What year had the most debris flow events?
The year with the most recorded debris flow events was 2022, with 358 events resulting in 6 fatalities and $19.5M in property damage.
How dangerous are debris flow events?
Debris Flow events have a high severity rating based on 68 fatalities and 187 injuries recorded from 2015 to 2025 across 31 states. Preparedness and early warning systems are critical for reducing risk.
Which states have the fewest debris flow events?
The states with the fewest debris flow events include MS (1 events), ME (1 events), WI (1 events). Geographic and climatic factors largely determine regional vulnerability to this hazard type.

Source: NOAA NCEI Storm Events Database (2015-2025) NOAA NCEI Storm Events Database (2015-2025) For informational purposes only

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Every figure on PlainHazard is rendered directly from FEMA federal disaster data, no number is typed in by an editor. This page draws directly on FEMA federal disaster data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or national statistics report, or report a data error.