Preview: automated baseline. Built automatically from federal data and not yet checked by hand. Check every figure against your own records before you use it in a plan.

Prince William County, VA

Risk-assessment baseline packet. County area 51153. Release 2026-10, data as of 2026-09-28.

Download the packet

PDF: PDF, for printing and reading. Word: Word document, tables ready to paste into a plan. Excel: Excel workbook, one sheet per section, full tables. JSON: Packet data (JSON), for analysts. Full packet as a web page. File manifest (checksums, source versions).

Plan clock

Approved, expires 2028-02-22

Plan
PDC 08 Northern Virginia Hazard Mitigation Plan (FEMA plan 108862)
Approved
2023-02-23
Expires
2028-02-22
As of
2026-09-28
Days
512 days to expiry
Update underway
FEMA tracker shows a plan in progress

Map group: Expires in 12 to 24 months.

What changed since your last plan (approved 2023-02-23)

New federal declarations
EM-3631-VA (1 declaration row; 1 counted incident)
Storm Events records since approval
114 (data through 2026-06-30)
Repetitive loss now
FMA RL 2, SRL 6 (44 CFR 77.2); any definition: 29
Repeat-flood change
First release: no prior release to compare.

Plan status for every jurisdiction in the plan

5 jurisdictions. Each row is that jurisdiction's own plan clock. Notes include other approved plans FEMA lists for the same jurisdiction.

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiryUpdate underwayNotes
Prince William CountyCountyApproved, expires 2028-02-22PDC 08 Northern Virginia Hazard Mitigation Plan (FEMA plan 108862)2023-02-232028-02-22512FEMA tracker shows a plan in progressmember approved 2023-03-07
Dumfries townTownApproved, expires 2028-02-22PDC 08 Northern Virginia Hazard Mitigation Plan (FEMA plan 108862)2023-02-232028-02-22512FEMA tracker shows a plan in progressmember approved 2023-04-18
Haymarket townTownApproved, expires 2028-02-22PDC 08 Northern Virginia Hazard Mitigation Plan (FEMA plan 108862)2023-02-232028-02-22512FEMA tracker shows a plan in progressmember approved 2023-06-05
Occoquan townTownApproved, expires 2028-02-22PDC 08 Northern Virginia Hazard Mitigation Plan (FEMA plan 108862)2023-02-232028-02-22512FEMA tracker shows a plan in progressmember approved 2023-03-07
Quantico townTownNo approved plan on recordnonenonenoneFEMA tracker shows a plan in progress

Plan 108862 also covers 16 other participants not listed on this page (named in the XLSX file).

State plan status and tribal plans in this state: see the state page.

What the packet contains

Sections in FEMA checklist order. Each heading names the review item its tables support; whether the item is satisfied is decided by the plan and its reviewers. Full tables are in the downloads above.

Supports B1-a Hazards

16 of the 18 National Risk Index hazards apply here; omission evidence is shown only where NRI rates a hazard "Not Applicable", no federal declaration names it and Storm Events has no record of it since 1996.

Highest expected annual loss (NRI, modeled): Inland Flooding, Heat Wave and Tornado.

Also check locally (not covered by NRI): dam failure (incl. upstream dams), levee failure, flash flood as its own subtype, ice jams, debris flows, erosion (riverine and coastal), land subsidence and sinkholes and expansive soils.

Check your state hazard mitigation plan's hazard list for this county; explain any hazard you drop.

Supports B1-b Location

  • Avalanche, Earthquake, Hurricane, Landslide, Tornado, Tsunami, Volcanic Activity and Wildfire: Census tract rating counts from the National Risk Index tract table (see B1-f). Tract maps and place names are not in this packet.
  • Coastal Flooding and Inland Flooding: The FEMA Flood Insurance Rate Map (FIRM) is the required location source for flooding. See the FEMA Flood Map Service Center (https://msc.fema.gov) for this county.
  • Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather: Affects the whole planning area; national data do not distinguish locations within the county. Confirm locally.

Supports B1-c Extent

Storm Events records for 14 of 20 hazard groups, with the scale, observed range and worst recorded event for each; the others say local data required.

  • Hail: 2.25 in hail, 2016-05-02
  • Thunderstorm Wind: 78 kt (90 mph), measurement type not recorded, Thunderstorm Wind, 1983-08-04
  • Tornado: F3 tornado, 1978-01-26, 0.7 mi path length (records before 1996 may include the whole path; rating and listing come from the county where the tornado began), 250 yd wide, $250,000 property; crops not recorded (1978 dollars), 1 direct death, 10 direct injuries

Supports B1-d Previous occurrences

20 federal declaration rows for this area (16 counted incidents), each with type, dates and county Public Assistance dollars.

New since the last plan (approved 2023-02-23): EM-3631-VA.

3 statewide declarations listed separately.

Hazards with no recorded events are stated as such (4 of 18).

Storm Events history: 1,060 records (notable ones in the PDF, all of them in the Excel file).

Supports B1-e Probability

FEMA annualized frequency (modeled) for each hazard, with a descriptor from a scale defined in the packet.

  • Highly likely: Coastal Flooding, Hail, Inland Flooding, Lightning, Strong Wind and Winter Weather
  • Likely: Cold Wave, Drought, Heat Wave, Ice Storm, Landslide and Tornado
  • Possible: Hurricane

Historical frequency by intensity band (tornado, hail, wind): 9 bands from Storm Events.

Supports B1-f Variation across the planning area

Range of census tract risk scores within the area for 18 hazards (93 tracts; rated tracts only).

5 member jurisdictions: plan clock, repeat-flood count, Public Assistance dollars and event records naming the place (starter, confirm locally).

Supports B2-a, B2-b Assets and impacts

Local data required

County-level starter. The plan must describe impacts for each participant and its own assets.

Storm Events damage since 2023-02-23: $4,719,000 in county-coded records (84 records); $0 reported for the zone (30 zone records). Data through 2026-06-30; nominal dollars.

Checklist of what to gather locally: Critical facilities and lifelines per hazard; A problem statement per participant per hazard; Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a); Future assets.

Supports B2-a Context

Population 481,359; building value $62,031,821,360 and agriculture value $14,955,296 (total, not at risk).

National Risk Index rating Relatively Moderate; social vulnerability Very Low; community resilience Relatively Moderate.

Supports B2-c Repetitive loss

Repetitive-loss properties, FMA definition (44 CFR 77.2): 2 repetitive loss, 6 severe repetitive loss. NFIP insurance definition: 27 and 4.

Mitigated 1; insured 15; NFIP data as of 2026-08-02. Counts by occupancy and for each member community are in the packet.

Releases

Monthly releases are planned (not yet running); files for a release never change. Earlier releases will be listed here with what changed between them. All releases.

Cite this

Hazard Plain (2026). Prince William County, VA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-28; County area 51153). Preview: automated baseline. https://hazardplain.org/va/51153/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Source citations for the plan's bibliography (8)

How this packet is built, its sources and its limits