FEMA disaster type · OpenFEMA declarations
Dam/Levee Break disasters in the United States
FEMA disaster declarations classified as "Dam/Levee Break" from 1964 to 2020 - which states are hit most often and how the count has changed over time.
- 6
- FEMA declarations
- 3
- States affected
- 1964
- Earliest year
- 2020
- Latest year
The verdict
According to FEMA's disaster declaration history, dam/levee break ranks #22 of the 27 distinct disaster types the agency has declared, accounting for 0.1% of all 5,218 declarations on record. It is rarer than 81% of the other declaration types FEMA tracks, based on total historical volume.
- #22 of 27
- FEMA disaster types, by declaration volume
- 0.1%
- share of all 5,218 FEMA declarations
- 6
- dam/levee break declarations, 1964–2020
Ranking reflects the count of Presidentially declared federal disasters per OpenFEMA, not event severity or economic loss; a rare declaration type can still be individually catastrophic.
How does Dam/Levee Break compare?
Dam/Levee Break vs. every FEMA declaration type
Declaration volume across all tracked incident types
6 19th percentile higher than 19% of 27 disaster types
Each bar is a band; taller bars hold more disaster types. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source FEMA OpenFEMA Disaster Declarations Summaries v2 · 2026-08-25
What shapes the dam/levee break record?
States with the most dam/levee break declarations
Wider bars = more FEMA declarations of this type
- California
California
3 declarations
- Michigan
Michigan
2 declarations
- Colorado 1
Colorado
1 declarations
What this shows California leads with 3 dam/levee break declarations among the states shown.
Dam/Levee Break declarations by year
Federal declaration cadence for this incident type across the OpenFEMA record.
Peak year in this series: 2020 (2 declarations). A declaration is a federal assistance trigger, not a raw event count.
How common are Dam/Levee Break disasters in the U.S.?
With so few declarations on record, the year-by-year pattern is necessarily sparse. The peak year on record was 2020, with 2 dam/levee break declarations issued that single year, a clustering driven by major multi-state events and the federal government's declaration cadence. The most recent year on record is 2020, with 2 declarations. Trends over the 56+ year history reflect how infrequently this disaster type crosses the federal declaration threshold at all.
FEMA has issued 6 federal disaster declarations classified as dam/levee break between 1964 and 2020, affecting 3 states and territories. Each declaration represents a formal federal recognition that an event exceeded state and local response capacity, unlocking Public Assistance, Individual Assistance, or Hazard Mitigation Grant Program funding depending on the declaration class (DR, EM, or FM). Raw declaration counts therefore measure the federal response footprint, which is a lagging and thresholded indicator: smaller events handled entirely at the state level never appear, and declaration thresholds have been recalibrated over the dataset's multi-decade history.
This disaster type's footprint is thin and scattered across the map. The three states with the most dam/levee break declarations on record are CA (3 declarations), MI (2 declarations), CO (1 declarations), consistent with how narrowly this hazard type is geographically concentrated.
What is actually in FEMA's dam/levee break file?
The complete OpenFEMA record is small enough to inspect title by title: 6 declaration rows resolve to 5 named records. A row is a federal administrative action, not necessarily a separate physical event.
- SEVERE STORMS AND FLOODING: Michigan; Major Disaster (DR) and Emergency (EM); 2020-07-09, 2020-05-21. OpenFEMA carries 2 declaration rows under this title.
- POTENTIAL FAILURE OF THE EMERGENCY SPILLWAY AT OROVILLE LAKE: California; Emergency (EM); 2017-02-14.
- FLOODING AS A RESULT OF A LEVEE BREAK: California; Major Disaster (DR); 2004-06-30.
- DAM FAILURE: Colorado; Major Disaster (DR); 1973-05-08.
- FLOOD DUE TO BROKEN DAM: California; Major Disaster (DR); 1963-12-21.
The repeated SEVERE STORMS AND FLOODING title shows why declaration totals should not be read as a literal incident count.
Which federal declaration does dam/levee break actually get?
With only 6 declarations on record, this type is too thin to express as a reliable percentage split, so the raw breakdown is: 4 Major Disaster (DR), 2 Emergency (EM). Each federal instrument carries different assistance: a Major Disaster declaration can unlock Individual Assistance and Hazard Mitigation funding, an Emergency declaration is narrower and faster, and Fire Management Assistance covers firefighting costs during an active incident.
Declarations by State
| # | State | Declarations |
|---|---|---|
| 1 | CaliforniaCA | 3 |
| 2 | MichiganMI | 2 |
| 3 | ColoradoCO | 1 |
Declarations by Year
| Year | Declarations |
|---|---|
| 2020 | 2 |
| 2017 | 1 |
| 2004 | 1 |
| 1973 | 1 |
| 1964 | 1 |
Recent Dam/Levee Break Declarations
Download all 6 declarations as CSV . Source data is public domain; our derived presentation is CC0. The table below lists the 6 most recent; the file carries every one.
| DR# | Title | State | Type | Date |
|---|---|---|---|---|
| 4547 | SEVERE STORMS AND FLOODING | MI | DR | 2020-07-09 |
| 3525 | SEVERE STORMS AND FLOODING | MI | EM | 2020-05-21 |
| 3381 | POTENTIAL FAILURE OF THE EMERGENCY SPILLWAY AT OROVILLE LAKE | CA | EM | 2017-02-14 |
| 1529 | FLOODING AS A RESULT OF A LEVEE BREAK | CA | DR | 2004-06-30 |
| 379 | DAM FAILURE | CO | DR | 1973-05-08 |
| 161 | FLOOD DUE TO BROKEN DAM | CA | DR | 1963-12-21 |
What this means for Dam/Levee Break declarations
Dam/Levee Break is rarer than 81% of the other declaration types FEMA tracks, with 6 FEMA declaration records; California leads with 3.
- California accounts for the largest share of dam/levee break declarations in this corpus. California profile
- See how states compare on raw FEMA declaration volume across all incident types. Most disasters ranking
- Learn what a FEMA declaration does and does not measure relative to NOAA storm events. Disaster-data guide
A federal declaration is a legal assistance trigger, not a count of every storm event or a forecast. For current threats follow the National Weather Service and local officials; in an emergency call 911.
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Source: FEMA OpenFEMA Disaster Declarations Summaries v2 For informational purposes only
Read our methodology - how this data is sourced, computed, and verified.
Related
Verify declarations with FEMA → Verify storm-event context with NOAA →
Every figure on PlainHazard is rendered directly from FEMA federal disaster data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or national statistics report, the data & editorial changelog, or report a data error.