Subsidence/Sinkhole

Hazard in Geological and Other Natural Hazards

A ground-collapse hazard — gradual or sudden — that damages foundations, roads and utilities from below.

Plans also call it: land subsidence, ground subsidence, karst, karst collapse, mine subsidence, aquifer compaction, cover-collapse

Talk to us about Subsidence/SinkholeAll 73 hazards →

What you’d hand your council

The first page of a Subsidence/Sinkhole evidence brief: likelihood, impact and readiness on your own scale, every figure sourced.

Evidence brief for Cedar Ridge County (example)

September 14, 2026

Subsidence/Sinkhole

Hazard in Geological and Other Natural Hazards, on the established threats & hazards list

Impact
5432112345

Likelihood

Likelihood
4

Likely — Expected within the decade — roughly once in 1 to 10 years (10–100% chance in any year).

Impact
2

Minor — Limited effects — few injuries, damage confined to a small area, brief localized disruption of services.

Readiness
3

Moderate — The organization has a generally established capability to manage this threat or hazard, but identifiable gaps remain. The organization could likely perform many required actions, though effectiveness may vary depending on conditions, staffing, resources, or complexity.

  • 2source documents
  • 58verified mentions
  • —federal declarations
  • —NRI risk score
Worked example: Cedar Ridge County is fictional. The scores illustrate the format and are nobody's decision. Open a full sample brief →

The national record

FEMA’s National Risk Index doesn’t model Subsidence/Sinkhole. Your team fills it with local evidence, and Hazzard shows the gap rather than a zero.

How it maps

The same hazard in the vocabularies your plan and FEMA already use.

FEMA National Risk Index
Not covered
FEMA declaration incident type
Not covered
NOAA Storm Events type
Not covered
Hazzard category
Geological and Other Natural Hazards, natural hazards

The national record

What the federal data says about Subsidence/Sinkhole: nothing yet

No federal dataset scores Subsidence/Sinkhole or files declarations under it. That's common for threats and emerging hazards, and it's why a brief for Subsidence/Sinkhole is built from your own plans, exercises and records. Hazzard shows the gap instead of inventing a number.

In your plan

What a Subsidence/Sinkhole profile needs, and where each part comes from

A local hazard mitigation plan profiles each hazard the same way (44 CFR 201.6). Here is how Hazzard fills each part for Subsidence/Sinkhole.

  1. Location

    44 CFR 201.6(c)(2)(i)

    Your documents

    No national layer maps Subsidence/Sinkhole. We draw the geographic extent from your plans, studies and annexes, cited to the page.

  2. Extent

    44 CFR 201.6(c)(2)(i)

    Your documents

    The magnitude your plans use for Subsidence/Sinkhole (a scale, a depth, an acreage, a duration), read from your documents and cited, so the profile states the strength you plan for.

  3. Previous occurrences

    44 CFR 201.6(c)(2)(i)

    Your documents

    FEMA files no declaration type for Subsidence/Sinkhole. The history comes from your after-action reports, incident records and plans.

  4. Probability of future events

    44 CFR 201.6(c)(2)(i)

    Your team decides

    No national dataset gives a frequency for Subsidence/Sinkhole. Your team scores likelihood on your scale from the evidence we organize.

  5. Vulnerability and impacts

    44 CFR 201.6(c)(2)(ii)

    Your documents

    The Census population profile and HHS emPOWER counts for context; the consequences themselves come from your plans and exercises.

  6. The assessment itself

    Your team decides

    Likelihood, impact and readiness for Subsidence/Sinkhole are drafted with every source attached, and a person on your team accepts each one. Hazzard never records a score on its own.

How we can help

How we’d help you prepare for Subsidence/Sinkhole

  1. 1

    We pull what the national record holds

    NRI ratings where FEMA models Subsidence/Sinkhole, any declarations, and the drought-relevant climate record. Where nothing models it, we say so.

  2. 2

    We read your plans and studies

    Mitigation plan, geologic or drought studies you already have, so the evidence you own is cited alongside the federal figures.

  3. 3

    You leave with a cited brief

    Likelihood, impact and readiness for Subsidence/Sinkhole on your own scale, every figure tied to its source, ready for the planning team or the council.

Also in Geological and Other Natural Hazards

Preparing for Subsidence/Sinkhole

Give Subsidence/Sinkhole the profile it deserves, even if it rarely makes the news.

Slow and rare hazards are the ones plans skim. We show what the national record says about yours, and where your plan has to rely on local knowledge instead. A person replies within one business day.

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