Hazard Plain Automated baseline

Sussex County, DE

Risk-assessment baseline packet

County FIPS:
10005
Release:
2026-10
Data as of:
2026-09-30
Storm Events data through:
2026-06-30

Hazard Plain is an independent product built from public federal data. It is not a FEMA document and is not reviewed or endorsed by FEMA or any state agency.

Hazard Plain release 2026-10, as of 2026-09-30.

Summary

Plan status as of 2026-09-30: Approved, expires 2028-01-02. Plan: Sussex County Hazard Mitigation Plan (FEMA plan 108411), approved 2023-01-03.

Update: FEMA tracker shows a plan in progress.

Since the plan was approved on 2023-01-03: 1 new hazard declaration (1 incident) and 90 NOAA Storm Events records; details under "What changed since your last plan".

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($42,608,060 a year), Hurricane ($35,311,960) and Cold Wave ($16,807,500).

The tables that follow are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); each heading says which item its tables support.

Plan clock

Status:
Approved, expires 2028-01-02
Plan:
Sussex County Hazard Mitigation Plan (FEMA plan 108411)
Approved:
2023-01-03
Days to expiry:
459
Update underway:
FEMA tracker shows a plan in progress

What changed since your last plan (approved 2023-01-03)

New federal declarations:
1 new hazard declaration (1 incident): DR-4916-DE (Severe Winter Storm)
Storm Events records since approval:
90 records (data through 2026-06-30)
Repetitive loss now:
FMA RL 4, SRL 26 (44 CFR 77.2); any definition: 307
Repeat-flood change:
this release sets the baseline count.

Sources: 1, 2, 4, 6 (numbered list at the end)

Plan status for every jurisdiction listed in this county: 26 rows, in the section "Plan clock: Plan status for every jurisdiction listed in this county" on the following pages.

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

Plan clock

Plan status for every jurisdiction listed in this county

Source: 1

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiryUpdate underwayNotes
Sussex CountyCountyApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-04-25
Bethany Beach townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-02-17
Bethel townTownNo approved plan on recordnonenonenoneFEMA tracker shows a plan in progress
Blades townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2025-01-13
Bridgeville townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progress
Dagsboro townTownNo approved plan on recordnonenonenoneFEMA tracker shows a plan in progress
Delmar townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2024-12-02
Dewey Beach townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-13
Ellendale townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-04
Fenwick Island townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-27
Frankford townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2024-12-02
Georgetown townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-02-13
Greenwood townTownNo approved plan on recordnonenonenoneFEMA tracker shows a plan in progress
Henlopen Acres townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progress
Laurel townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2024-11-18
Lewes cityCityApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-08-14
Milford cityCityExpired on 2026-04-19Kent County Hazard Mitigation Plan (FEMA plan 106435)2021-04-202026-04-19-164FEMA tracker shows a plan approvable pending adoptionNot yet eligible: adopt the approved plan.
Millsboro townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progress
Millville townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-10
Milton townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-02-13
Ocean View townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progress
Rehoboth Beach cityCityApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2024-11-15
Seaford cityCityApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-10
Selbyville townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2023-01-10
Slaughter Beach townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progressthis jurisdiction approved 2024-12-11
South Bethany townTownApproved, expires 2028-01-02Sussex County Hazard Mitigation Plan (FEMA plan 108411)2023-01-032028-01-02459FEMA tracker shows a plan in progress

Supports FEMA checklist item B1-a: hazard identification

Hazards NRI does not cover (local data needed)

  • 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
  • expansive soils

The 18 National Risk Index hazards, ranked by expected annual loss (EAL)

Sources: 5, 6

Rank by EALHazardNRI risk ratingEAL ratingEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL total (see note)modeled dollars per yearStorm Events records, 1996 to 2026-06-30countStorm Events coverage note
1Inland FloodingRelatively ModerateRelatively Moderate$40,254,893$1,798,764$554,403$42,608,060112
2HurricaneRelatively HighRelatively High$25,442,157$9,355,258$514,546$35,311,9607
3Cold WaveRelatively HighRelatively High$3,262$53,181$16,751,057$16,807,50027Includes 1 Frost/Freeze record (outside NRI's Cold Wave definition; counted in this table and in B1-d, not in the B1-e descriptor).
4Coastal FloodingVery HighVery High$14,125,960n/a$46,980$14,172,94394
5Heat WaveRelatively ModerateRelatively Moderateunder $1$4,172$2,307,003$2,311,17581
6TornadoRelatively LowRelatively Low$842,306$7,716$739,863$1,589,88511
7EarthquakeRelatively LowRelatively Low$1,294,797n/a$227,760$1,522,557Storm Events does not record earthquakes.
8Strong WindRelatively HighRelatively Moderate$540,151$53,564$701,726$1,295,442518Includes 68 High Wind and 148 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
9DroughtRelatively ModerateRelatively Moderaten/a$1,060,189n/a$1,060,18953
10Winter WeatherVery HighRelatively High$280,076$276$446,463$726,815155Includes 2 Sleet records (outside NRI's Winter Weather definition).
11LightningRelatively HighRelatively Moderate$226,726n/a$437,797$664,52281
12WildfireRelatively LowRelatively Low$472,767$1,916$63,389$538,0729
13Ice StormRelatively ModerateRelatively Moderate$323,527n/a$61,934$385,4610Declared 1 time; no Storm Events record of this type.
14HailRelatively LowRelatively Low$26,314$279,024$353$305,69135
15LandslideVery LowVery Low$1,105n/a$3$1,1090No recorded events in Storm Events since 1996 (data through 2026-06-30).
TsunamiInsufficient DataInsufficient Datan/an/an/an/a1

Total = buildings + agriculture + population equivalence; FEMA values each expected death (or 10 injuries) at $13.7 million (2024 dollars).

NRI risk rating combines expected annual loss with social vulnerability and community resilience; EAL rating rates expected annual loss alone. Both compare this county with all U.S. counties.

Local data needed: state and local landslide records (Storm Events records this hazard only in part).

Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: avalanche and volcanic activity. That is the evidence for leaving them out of the plan.

The state hazard mitigation plan also lists hazards for this county; FEMA asks the plan to explain any hazard it leaves out.

Supports FEMA checklist item B1-b: hazard location

Affects the whole county (national data give no location within it): Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather.

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.

Hazards that vary within the county: highest-rated census tracts

Source: 5

HazardHighest-rated census tractsNRI risk rating, score 0 to 100
Earthquaketract 501.04 (Relatively Low, 77.2); tract 504.06 (Relatively Low, 72.7); tract 503.04 (Relatively Low, 67.5)
Hurricanetract 503.02 (Relatively High, 96.9); tract 517.02 (Relatively High, 95.3); tract 505.06 (Relatively High, 95.0)
Landslidetract 517.01 (Relatively Low, 81.8); tract 501.03 (Very Low, 79.1); tract 518.01 (Very Low, 78.6)
Tornadotract 504.06 (Relatively Low, 52.5); tract 501.04 (Relatively Low, 51.9); tract 503.02 (Relatively Low, 51.8)
Tsunamino tract has a National Risk Index rating for this hazard
Wildfiretract 501.03 (Relatively Moderate, 91.5); tract 518.01 (Relatively Moderate, 90.1); tract 509.05 (Relatively Moderate, 89.6)

Up to 3 census tracts per hazard, highest National Risk Index rating first, then highest score; a tract number is the Census tract number (for example 501.04 is Census Tract 501.04). FEMA's Resilience Analysis and Planning Tool maps the National Risk Index for every tract: https://www.fema.gov/emergency-managers/practitioners/resilience-analysis-and-planning-tool

Supports FEMA checklist item B1-c: hazard extent

Extent: scale, observed range and worst recorded event per hazard

Sources: 6, 7

HazardScaleRecordscount and yearsObserved rangeWorst recorded eventMost damaging (when different)How it applies to jurisdictionsNote
Coastal Flood, Storm Surge/Tidenone in data (flood depth: FIRM)94 records, 1996 to 2026 (94 zone-level)Coastal Flood, 2009-11-12, $40,000,000 property; $0 crops (2009 dollars); NWS zone DEZ004Countywide (zone-level records).Flood depth: see the FEMA Flood Insurance Rate Map.
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill26 records, 1996 to 2015 (26 zone-level)1 day to 16 days (median 2 days); 21 with a recorded value16 consecutive days, 2003-01-14 to 2003-01-29, zone-levelCountywide (zone-level records).Cold/Wind Chill records from May to September (a frost night, not a cold wave) are counted but not used for the longest run.
Frost/Freeze (outside NRI's Cold Wave definition)crop damage1 record, 2007 (1 zone-level)No crop damage reported in 1 record.Countywide (zone-level records).
DroughtU.S. Drought Monitor scale (D0 to D4)53 records, 1997 to 2012 (53 zone-level)1 day to 288 days (median 20 days); 17 with a recorded value288 days (about 9.5 months), 2007-07-24 to 2008-05-06, a run of 11 consecutive Storm Events drought records, zone-levelDrought, 1999-09-01, property not reported; $20,100,000 crops (zone total, 1999 dollars)Countywide (zone-level records).Storm Events enters a drought at D2 or worse east of the Rockies and D3 or worse from the Rockies west (NWS Instruction 10-1605); NRI drought counts D3 and D4 only.
EarthquakeModified Mercalli (local data)0Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hailhail size (inches)48 records, 1968 to 20250.75 in to 2.25 in (median 1 in); 48 with a recorded value2.25 in hail, 2022-05-16Hail, 2009-06-13, $0 property; $300,000 crops (2009 dollars)Event records naming jurisdictions in the plan: Laurel town (4 records), Millsboro town (4 records), Blades town (3 records), Delmar town (3 records), Bridgeville town (2 records), Greenwood town (2 records), Rehoboth Beach city (2 records), Bethany Beach town (1 record), Dewey Beach town (1 record), Ellendale town (1 record); and 2 more jurisdictions (see the Excel file).
Excessive Heat, Heatheat index (in event narratives)81 records, 1996 to 2025 (81 zone-level)1 day to 10 days (median 3 days); 54 with a recorded value10 consecutive days, 2002-08-11 to 2002-08-20, zone-levelCountywide (zone-level records).Heat records from November to March (unseasonable warmth, not a heat wave) are counted but not used for the longest run.
Hurricane, Tropical Storm, Tropical DepressionSaffir-Simpson7 records, 1996 to 2020 (7 zone-level)Strongest recorded: Hurricane record (NOAA event type 'Hurricane (Typhoon)'), 1999-09-16, 57 kt (66 mph), measurement type not recorded, $50,000 property; $0 crops (1999 dollars); NWS zone DEZ004Most damaging recorded: Tropical Storm, 2003-09-18, $8,000,000 property; crops not reported (zone total, 2003 dollars)Countywide (zone-level records).Storm Events files every zone of a storm's episode under the storm's type; flooding from the storm is filed as Flood or Flash Flood records.
Ice StormSperry-Piltz ice scale (local data)0
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)112 records, 1999 to 2025 (12 zone-level)Flash Flood, 2001-08-11, $1,100,000 property; crops not reported (2001 dollars)Event records naming jurisdictions in the plan: Bethany Beach town (11 records), Blades town (5 records), Bridgeville town (5 records), Dewey Beach town (4 records), Ellendale town (4 records), Georgetown town (4 records), Ocean View town (4 records), Dagsboro town (3 records), Millsboro town (3 records), Milton town (3 records); and 11 more jurisdictions (see the Excel file). Zone-level records (12) apply countywide.Flood depth: see the FEMA Flood Insurance Rate Map. Storm Events damage is often $0 or blank for floods, major ones included; FEMA Public Assistance by declaration (B1-d) shows which floods cost the most.
Debris Flownone (count and damage only)0
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)81 records, 1998 to 2026Lightning, 2003-08-30, $800,000 property; $0 crops (2003 dollars)Event records naming jurisdictions in the plan: Lewes city (8 records), Seaford city (7 records), Ocean View town (6 records), Rehoboth Beach city (6 records), Georgetown town (5 records), Millville town (5 records), Bethany Beach town (4 records), Milton town (4 records), Dewey Beach town (3 records), Bridgeville town (2 records); and 10 more jurisdictions (see the Excel file).Storm Events lists lightning with damage or casualties.
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)216 records, 1996 to 2026 (216 zone-level)35 kt (40 mph) to 71 kt (82 mph) (median 44 kt (51 mph)); 183 with a recorded value71 kt (82 mph), measurement type not recorded, High Wind, 1998-01-28; NWS zone DEZ004High Wind, 2012-10-29, $200,000 property; $0 crops (zone total, 2012 dollars)Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)372 records, 1957 to 202650 kt (58 mph) to 100 kt (115 mph) (median 50 kt (58 mph)); 306 with a recorded value100 kt (115 mph), measurement type not recorded, Thunderstorm Wind, 1991-07-07, 2 direct injuriesThunderstorm Wind, 1995-11-11, $1,000,000 property; crops not recorded (1995 dollars)Event records naming jurisdictions in the plan: Georgetown town (24 records), Bridgeville town (22 records), Dewey Beach town (22 records), Laurel town (20 records), Greenwood town (16 records), Blades town (15 records), Lewes city (15 records), Millsboro town (11 records), Seaford city (10 records), Dagsboro town (9 records); and 12 more jurisdictions (see the Excel file).
TornadoEnhanced Fujita (Fujita before Feb 2007)28 records, 1955 to 2025F/EF0 to F/EF3 (median F/EF1); 28 with a recorded valueEF3 tornado, 2023-04-01, 14.3 mi within this county, 700 yd wide, $0 property; $0 crops (2023 dollars), 1 direct deathTornado, 1984-05-08, $250,000 property; crops not recorded (1984 dollars)Event records naming jurisdictions in the plan: Bethel town (2 records), Bridgeville town (1 record), Dagsboro town (1 record), Dewey Beach town (1 record), Ellendale town (1 record), Frankford town (1 record), Greenwood town (1 record), Slaughter Beach town (1 record).Before 1996 a tornado is listed once, under the county where it began, with its whole path's rating and length; from 1996 on, each county lists its own segment. Length is not used to rank tornadoes (see Methods).
Tsunaminone (count and damage only)1 record, 2013 (1 zone-level)No damage reported in 1 record.Countywide (zone-level records).
Wildfireacres burned (local data)9 records, 2000 to 2006 (7 zone-level)Wildfire, 2006-03-14, $5,000 property; crops not reported (2006 dollars); NWS zone DEZ003Event records naming jurisdictions in the plan: Dagsboro town (1 record), Georgetown town (1 record). Zone-level records (7) apply countywide.
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)155 records, 1996 to 2026 (155 zone-level)Winter Storm, 2010-02-09, $1,500,000 property; $0 crops (2010 dollars); NWS zone DEZ004Winter Storm, 2010-02-09, $1,500,000 property; $0 crops (zone total, 2010 dollars)Countywide (zone-level records).

Where a hazard names more than 10 jurisdictions, the table lists the 10 with the most records; every one is in the Excel file, sheet "B1-c Extent".

In event narratives only (local data needed): wind chill, temperature, heat index, ice thickness, acres burned and snow depth; any physical measure of debris flow, lightning and tsunami.

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records from zones that no NWS zone-county file places in this county (mostly before 2020) are not counted here (the Methods page explains the zone matching).

Dollars are nominal (as reported), labeled with the year; not adjusted for inflation.

Supports FEMA checklist item B1-d: previous occurrences

Federal declarations for this county: 20 declarations covering 15 separate hazard incidents counted in this packet (declarations for the same incident count once; non-natural and evacuation-only declarations are not counted).

Federal disaster declarations for this county

Sources: 1, 2, 3

DeclaredIncident beganFEMA numberTypeTitleMapped hazardCounty Public Assistancefederal share obligated, nominal dollarsFlagsNotes
2026-05-292026-02-22DR-4916-DEMajor disasterSevere Winter StormWinter Weather$139,557.68new since last plan; within last 5 years
2020-04-052020-01-20DR-4526-DEMajor disasterCOVID-19 PandemicNon-natural, not counted$29,503,949.62
2020-03-132020-01-20EM-3449-DEEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4526
2016-03-162016-01-22DR-4265-DEMajor disasterSevere Winter Storm and SnowstormWinter Weather$998,622.64
2012-11-162012-10-27DR-4090-DEMajor disasterHurricane SandyHurricane$436,531.65
2012-10-292012-10-27EM-3357-DEEmergencyHurricane SandyHurricaneno Public Assistance recordedsame incident as DR-4090
2011-09-302011-08-25DR-4037-DEMajor disasterHurricane IreneHurricane$288,324.13
2011-08-282011-08-26EM-3336-DEEmergencyHurricane IreneHurricaneno Public Assistance recordedsame incident as DR-4037
2010-03-312010-02-05DR-1896-DEMajor disasterSevere Winter Storms and SnowstormsWinter Weather$809,249.43
2006-07-052006-06-23DR-1654-DEMajor disasterSevere Storms and FloodingInland Flooding$90,742.72
2005-09-302005-08-29EM-3263-DEEmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
2003-09-202003-09-18DR-1494-DEMajor disasterHurricane IsabelHurricane$207,907.86
2003-03-202003-02-14EM-3183-DEEmergencySnowWinter Weather$115,439.27
1998-02-131998-01-28DR-1205-DEMajor disasterSevere Winter Storms, High Winds, and FloodingInland Flooding; Strong Wind; Winter Weatherno Public Assistance recorded
1996-01-121996-01-06DR-1082-DEMajor disasterBlizzard of 96 (Severe Snow Storm)Winter Weatherno Public Assistance recorded
1994-03-161994-02-08DR-1017-DEMajor disasterSevere Ice Storms and FloodingIce Storm; Inland Floodingno Public Assistance recorded
1993-03-181993-03-13EM-3111-DEEmergencySevere Snowfall & Winter StormWinter Weatherno Public Assistance recorded
1993-01-151992-12-11DR-976-DEMajor disasterSevere Coastal Storm & FloodingCoastal Floodingno Public Assistance recorded
1992-02-061992-01-04DR-933-DEMajor disasterSevere Coastal StormCoastal Floodingno Public Assistance recorded
1965-08-181965-08-18DR-207-DEMajor disasterWater ShortageDroughtno Public Assistance recorded

County Public Assistance: applicants the FEMA record places in this county, including any state agencies FEMA files there; statewide rows are listed on the state page; federal share obligated, nominal dollars.

Statewide declarations

Source: 2

DeclaredIncident beganFEMA numberTypeTitleMapped hazard
1962-03-091962-03-09DR-126-DEMajor disasterSevere Storms, High Tides & FloodingInland Flooding (primary); also designated: Coastal Flooding

FEMA recorded these with designated area Statewide and no county, so they are listed on every county page in the state and not counted with county rows. Local data needed: whether each one affected this county.

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

HazardStorm Events records, all years on file(years in the Period column)Since plan approvalrecordsIn the 12 months before plan approvalrecordsLast 5 yearsrecordsDeclared incidents, all yearsseparate disastersDeclared since approvalseparate disastersPeriodStatement
Coastal Flooding9415522201996 to 2026-06-30
Cold Wave27000001996 to 2026-06-30Includes 1 Frost/Freeze record.
Drought53000101996 to 2026-06-30
Earthquake000000Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail48358001955 to 2026-06-30
Heat Wave81202001996 to 2026-06-30
Hurricane7000301996 to 2026-06-30
Ice Storm0000101996 to 2026-06-30No Storm Events records of this type; 1 federal declared incident (see declarations table)
Inland Flooding112606301996 to 2026-06-30
Landslide0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Lightning81112001996 to 2026-06-30
Strong Wind588492372101955 to 2026-06-30Includes 68 High Wind and 148 Strong Wind records.
Tornado28404001950 to 2026-06-30
Tsunami1000001996 to 2026-06-30
Wildfire9000001996 to 2026-06-30
Winter Weather15510616711996 to 2026-06-30Includes 2 Sleet records.

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationFlagsWhy listed
2023-04-01TornadoEF3, 14.3 mi within this county, 700 yd wide$0 property; $0 crops (2023 dollars)1, 0DUBLIN HILL to ELLENDALEnew since last plan; within last 5 yearsdeaths or injuries recorded
2010-02-09Winter Storm$1,500,000 property; $0 crops (zone total, 2010 dollars)0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleet
2009-11-12Coastal Flood$40,000,000 property; $0 crops (zone total, 2009 dollars)0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: Coastal Flood, Storm Surge/Tide
2007-07-24Drought$0 property; $0 crops (zone total, 2007 dollars)0, 0NWS zone DEZ003 (INLAND SUSSEX), zone-levelB1-c worst recorded: Drought
2007-02-06Extreme Cold/Wind Chill$0 property; $0 crops (zone total, 2007 dollars)1, 1NWS zone DEZ003 (INLAND SUSSEX), zone-leveldeaths or injuries recorded
2003-01-14Cold/Wind Chilldamage not reported0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill
2002-08-11Heatdamage not reported0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: Excessive Heat, Heat
2001-08-11Flash Flood$1,100,000 property; crops not reported (2001 dollars)0, 0SOUTHWEST PORTIONB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
1999-09-16Hurricane (NOAA event type 'Hurricane (Typhoon)')$50,000 property; $0 crops (zone total, 1999 dollars)0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression
1998-01-28High Wind71 kt (82 mph), measurement type not recordeddamage not reported0, 0NWS zone DEZ004 (DELAWARE BEACHES), zone-levelB1-c worst recorded: High Wind and Strong Wind
1991-07-07Thunderstorm Wind100 kt (115 mph), measurement type not recordeddamage not recorded (pre-1996 record)0, 2location not recordedB1-c worst recorded: Thunderstorm Wind
1984-05-08TornadoF1, 6 mi path length (whole path, pre-1996), 150 yd wide$250,000 property; crops not recorded (1984 dollars)0, 8location not recordeddeaths or injuries recorded

The full list is in the Excel file, sheet "B1-d Storm Events history" (1,284 rows).

Location is the place NOAA recorded, as written in its data; it need not be a jurisdiction in this plan.

Local data needed: state-declared emergencies, from your state emergency management agency (federal data do not include them).

FEMA's declaration data list no tribal or special-area declarations for this state.

Supports FEMA checklist item B1-e: probability of future events

Probability: FEMA annualized frequency and descriptor per hazard

Sources: 5, 6

HazardFEMA annualized frequency (modeled)unit per rowUnitIn plain termsDescriptorDescriptor basisNRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)NRI periodLocationNote
Coastal Flooding3.65events per year at a location (modeled)about 3.7 per year at a given location in the countyHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-fDescriptor from NRI: the rate at a location is 1 or more a year, so the county rate is at least that.
Cold Wave0.787event-days per yearabout 0.787 days per yearLikelyStorm Events event-days in 11 of 30 years, 1996 to 2025 (36.7%)11.92005-11-12 to 2024-11-12 (19 years)countywide
Drought4.26event-days per yearabout 4.26 days per yearLikelyStorm Events event-days in 10 of 30 years, 1996 to 2025 (33.3%)2032000 to 2025 (25.25 years; D3 and D4 only)countywide
Earthquake0.00104annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 0.104%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail0.925events per yearabout 0.92 per yearLikelyFEMA annualized frequency (modeled)35.2 (modeled)1986 to 2023 (38 years)countywide
Heat Wave5.03event-days per yearabout 5.03 days per yearLikelyStorm Events event-days in 22 of 30 years, 1996 to 2025 (73.3%)64.12005-11-12 to 2024-11-12 (19 years)countywide
Hurricane0.169events per yearabout 1 in 6 yearsLikelyFEMA annualized frequency (modeled)701851 to 2024 (Atlantic)see B1-fNRI counts hurricane and tropical storm tracks passing within storm-force wind range; federal declarations are in B1-d.
Ice Storm0.401event-days per yearabout 0.401 days per yearStorm Events event-days in 0 of 30 years, 1996 to 2025 (0%)231946-12-31 to 2014-02-12 (67 years)countywideNo Storm Events ice storm record, 1996 to 2025
Inland Flooding2.54event-days per yearabout 2.54 days per yearLikelyStorm Events event-days in 23 of 30 years, 1996 to 2025 (76.7%)711996 to 2023 (28 years)see B1-f
Landslide0.125events per year (modeled)about 1 in 8 yearsLikelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning32.8days per year with a strikeabout 32.8 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind2.36events per yearabout 2.36 per yearHighly likelyFEMA annualized frequency (modeled)731986 to 2023 (38 years)countywide
Tornado0.34events per yearabout 1 in 3 yearsLikelyFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Tsunamiannual probability at the most exposed location (used in place of a county value)PossibleStorm Events records in 1 of 30 years, 1996 to 2025 (3.33%)not shownmodeledsee B1-f
Wildfire0.000987annual probability at a locationchance a given location in the county burns in a year: 0.0987%LikelyStorm Events records in 5 of 30 years, 1996 to 2025 (16.7%)not shownmodeledsee B1-f
Winter Weather7.03event-days per yearabout 7.03 days per yearHighly likelyStorm Events event-days in 28 of 30 years, 1996 to 2025 (93.3%)1062005-11-12 to 2024-11-12 (19 years)countywide

FEMA annualized frequency (modeled) is the National Risk Index v1.20 (December 2025) estimate of how often a hazard affects this county in a year; it is not recorded events divided by years, and its unit differs by hazard (events, event-days, or days with a lightning strike per year). For earthquake, wildfire, coastal flooding and tsunami the value is the chance (or number of events) at a location in the county, not across the county, so no "1 in N years" is given and the descriptor comes from Storm Events where it has a record (none for earthquake). The Methods page gives each hazard's method, from FEMA's National Risk Index Technical Documentation v1.20.

Where NRI gives event-days, the descriptor comes from the share of years with a Storm Events record; NRI's source records more events, so the two differ.

Descriptor scale used in this packet (defined per unit)

Sources: 5, 6

UnitDescriptorDefinition
events per yearHighly likely1 or more per year
events per yearLikelyabout once in 1 to 10 years
events per yearPossibleabout once in 10 to 100 years
events per yearUnlikelyless than once in 100 years
annual probabilityLikely10% to under 100% chance in a given year
annual probabilityPossible1% to under 10% chance in a given year
annual probabilityUnlikelyunder 1% chance in a given year
event-days (share of years)Highly likelyevent-days recorded in 90% or more of years
event-days (share of years)Likelyevent-days recorded in 10% to under 90% of years
event-days (share of years)Possibleevent-days recorded in some years but under 10% of years
lightning strike-daysHighly likelycloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

HazardBandYearsEventscounty-coded recordsYears in periodEvents per yearevents / years
Hail1.00-1.99 in1996 to 202522300.733
Hail2.00 in+1996 to 20252300.0667
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 2025270309
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 202511300.367
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 20257300.233
TornadoEF0-11996 to 20259300.3
TornadoEF2-31996 to 20252300.0667
TornadoEF4-51996 to 20250300
Tornadounrated (EFU)1996 to 20250300

The bands show how often events of each severity were recorded in this county, to profile how severe events have been (FEMA's probability item asks for the range of intensities).

Hail smaller than 1 inch is not counted: on 2010-01-05 the National Weather Service raised its severe-hail threshold from 3/4 inch to 1 inch, so smaller reports became less common after 2009 (NWS Service Change Notice 09-52). NRI hail frequency uses a 0.75 inch threshold.

Optional: future conditions. Not a required item in the 2025 FEMA Local Mitigation Planning Policy Guide; some states ask for it. The federal Climate Mapping for Resilience and Adaptation (CMRA) site gives county exposure to future climate conditions (https://resilience.climate.gov/).

Supports FEMA checklist item B1-f: hazards that vary across jurisdictions

Range of census tract risk within the county

Source: 5

HazardTractsrated of allNRI risk score, 0 to 100Tracts by rating
MinMedianMax
Coastal Flooding67 of 7470.393.499.9Very High 9, Relatively High 13, Relatively Moderate 21, Relatively Low 9, Very Low 15, No Rating 7
Cold Wave74 of 7415.987.496.3Very High 3, Relatively High 54, Relatively Moderate 16, Very Low 1
Drought68 of 7467.085.196.0Relatively Moderate 18, Relatively Low 30, Very Low 20, No Rating 6
Earthquake74 of 744.041.877.2Relatively Low 39, Very Low 35
Hail74 of 741.026.184.7Relatively Moderate 3, Relatively Low 20, Very Low 51
Heat Wave74 of 741.645.574.3Relatively Moderate 27, Relatively Low 35, Very Low 12
Hurricane74 of 7453.590.696.9Relatively High 44, Relatively Moderate 28, Relatively Low 2
Ice Storm74 of 742.056.276.5Relatively Moderate 6, Relatively Low 63, Very Low 5
Inland Flooding74 of 740.456.189.3Relatively High 8, Relatively Moderate 37, Relatively Low 23, Very Low 6
Landslide74 of 7412.558.081.8Relatively Low 1, Very Low 73
Lightning74 of 740.545.370.2Relatively Moderate 30, Relatively Low 43, Very Low 1
Strong Wind74 of 742.345.485.1Relatively High 2, Relatively Moderate 24, Relatively Low 47, Very Low 1
Tornado74 of 741.730.752.5Relatively Low 44, Very Low 30
Tsunami0 of 74Insufficient Data 74
Wildfire74 of 7448.779.791.5Relatively Moderate 8, Relatively Low 56, Very Low 10
Winter Weather74 of 7416.583.393.8Relatively High 49, Relatively Moderate 24, Very Low 1

Drought: Agriculture is all of NRI's expected annual loss for this hazard in the county, so the tract range mostly reflects where crop and livestock value is.

Hail: Agriculture is 91% of NRI's expected annual loss for this hazard in the county, so the tract range mostly reflects where crop and livestock value is.

Rated tracts only: No Rating (score 0.0), Not Applicable and Insufficient Data tracts are counted but not used for the minimum, median and maximum.

The score ranks a tract against all U.S. tracts (100 = highest). The rating is FEMA's category for the tract's risk value, computed differently, so the two can disagree.

Frequency data for cold wave, drought, hail, heat wave, ice storm, lightning, strong wind and winter weather are county-wide or coarse (49 km grid or NWS zone), the same for every jurisdiction; the tract range mostly reflects where buildings and people are (crop and livestock value where a line above names agriculture).

Each jurisdiction (starting figures from federal data)

Sources: 1, 3, 4, 6

JurisdictionTypePlan statusRepetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definitionPublic Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollarsEvent records naming this placeall years; since its planNotes
Sussex CountyCountyApproved, expires 2028-01-02FMA RL 2, SRL 14; any 145$213,298.910 total; 0 since its plan
Bethany Beach townTownApproved, expires 2028-01-02FMA RL 0, SRL 2; any 49$39,005.5620 total; 3 since its plan
Bethel townTownNo approved plan on recordFMA RL 0, SRL 0; any 0no Public Assistance recorded8 total; no approved plan
Blades townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$6,204.6824 total; 2 since its plan
Bridgeville townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$42,744.4332 total; 6 since its plan
Dagsboro townTownNo approved plan on recordFMA RL 0, SRL 0; any 0no Public Assistance recorded15 total; no approved plan
Delmar townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$11,989.609 total; 0 since its plan
Dewey Beach townTownApproved, expires 2028-01-02FMA RL 0, SRL 5; any 32$34,016.6531 total; 3 since its plan
Ellendale townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0no Public Assistance recorded13 total; 2 since its plan
Fenwick Island townTownApproved, expires 2028-01-02FMA RL 2, SRL 1; any 9$59,022.100 total; 0 since its plan
Frankford townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0no Public Assistance recorded11 total; 3 since its plan
Georgetown townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$47,978.1734 total; 1 since its plan
Greenwood townTownNo approved plan on recordFMA RL 0, SRL 0; any 0$6,046.4521 total; no approved plan
Henlopen Acres townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$25,476.402 total; 0 since its plan
Laurel townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$101,168.5328 total; 5 since its plan
Lewes cityCityApproved, expires 2028-01-02FMA RL 0, SRL 0; any 15$99,164.8323 total; 1 since its plan
Milford cityCityExpired on 2026-04-19FMA RL 0, SRL 2; any 7$180,301.610 total; 0 since its planWhole community, including the part in Kent County; in-county portion (county table): FMA RL 0, FMA SRL 0, NFIP RL 3, NFIP SRL 0, any category 3.
Millsboro townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 1$25,204.1019 total; 2 since its plan
Millville townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0no Public Assistance recorded9 total; 1 since its plan
Milton townTownApproved, expires 2028-01-02FMA RL 0, SRL 1; any 1$29,847.5415 total; 1 since its plan
Ocean View townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 1$31,058.2013 total; 1 since its plan
Rehoboth Beach cityCityApproved, expires 2028-01-02FMA RL 0, SRL 1; any 8$1,112,733.1513 total; 0 since its plan
Seaford cityCityApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$202,356.1620 total; 1 since its plan
Selbyville townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 0$33,207.435 total; 0 since its plan
Slaughter Beach townTownApproved, expires 2028-01-02FMA RL 0, SRL 0; any 2$9,856.096 total; 0 since its plan
South Bethany townTownApproved, expires 2028-01-02FMA RL 0, SRL 2; any 41$77,735.450 total; 0 since its plan

Repetitive-loss counts are for whole NFIP communities, which can extend beyond this county (see the note in B2-c).

County Public Assistance in B1-d also includes applicants filed under the county that are not jurisdictions in this plan (for example state agencies, special districts and nonprofits), so the jurisdiction rows add up to less.

Supports FEMA checklist items B2-a and B2-b: vulnerability and potential impacts

Local data needed

The table below gives county-level starting figures; the plan describes impacts for each jurisdiction and its own assets.

  • Critical facilities and lifelines per hazard
  • A problem statement per jurisdiction per hazard
  • Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a)
  • Future assets

County-level starter: exposure, expected annual loss and damage since the plan

Sources: 1, 2, 3, 5, 6, 7

HazardBuilding exposuremodeled dollarsAgriculture exposuremodeled dollarsPopulation exposedpeopleEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL as % of exposurebuildings; agriculture where notedStorm Events damage since 2023-01-03county-coded records, property plus crops, nominal dollarsZone-level damage since planproperty plus crops, reported for the zonePublic Assistance since plannominal dollars; see noteNote
Coastal Flooding$10,806,278,949n/a20,444$14,125,960n/a$46,9800.131%$0
Cold Wave$74,497,727,033$1,303,773,481237,214$3,262$53,181$16,751,057under 0.0001%
Droughtn/a$192,148,649n/an/a$1,060,189n/a0.552% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$124,619,323,001n/a237,378$1,294,797n/a$227,7600.00104%
Hail$74,497,727,033$1,303,773,481237,214$26,314$279,024$353under 0.0001%$0
Heat Wave$74,497,727,033$1,303,773,481237,214under $1$4,172$2,307,003under 0.0001%
Hurricane$74,492,829,350$1,303,735,830237,208$25,442,157$9,355,258$514,5460.0342%
Ice Storm$73,095,713,845n/a233,869$323,527n/a$61,9340.000443%
Inland Flooding$74,162,597,140$73,460,54219,816$40,254,893$1,798,764$554,403n/a (see note)$0NRI counts the full building value of any census block with some flood loss; this is not the value of buildings in the floodplain. Use local FIRM overlays for B2-a/B2-b.
Landslide$192,591,385n/a516$1,105n/a$30.000574%
Lightning$74,497,727,033n/a237,214$226,726n/a$437,7970.000304%$10,000
Strong Wind$74,497,727,033$1,303,773,481237,214$540,151$53,564$701,7260.000725%$30,000
Tornado$74,497,727,033$1,303,773,481237,214$842,306$7,716$739,8630.00113%$0
Tsunamin/an/an/an/an/an/aNRI publishes no building exposure for this county
Wildfire$5,864,866,086$241,950,89237,528$472,767$1,916$63,3890.00806%
Winter Weather$74,497,727,033$1,303,773,481237,214$280,076$276$446,4630.000376%$0$139,557.68

Totals since 2023-01-03 (Storm Events through 2026-06-30): 58 county-coded records, 17 with a damage value recorded (including $0), $40,000; 32 zone-level records, 20 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: $139,557.68 on 1 counted declaration.

FEMA does not split Public Assistance by hazard. A declaration mapped to several hazards is listed under each of them with its full amount, so the per-hazard column does not add up to the total; the unit total counts each declaration once.

NRI computes earthquake exposure on its own basis, so it exceeds the county building value in B2-a.

Supports FEMA checklist item B2-a: vulnerability (county context)

County context

Source: 5

MeasureValue
Population237,214
Building value (total, not at risk)$74,497,727,033
Agriculture value (total, not at risk)$1,303,773,481
NRI risk rating (all hazards)Relatively Moderate
Expected annual loss, buildings and agriculture, all hazards$96,448,099
Expected annual loss, population equivalence, all hazards (NRI values each statistical life at $13.7M; a modeled value of expected deaths and injuries, not property damage)$22,853,277
Social vulnerability ratingRelatively High
Community resilience ratingRelatively Moderate
NRI versionDecember 2025

FEMA's all-hazard expected annual loss adds buildings, agriculture and population equivalence; this table gives the property part and the population-equivalence part as separate rows.

Social vulnerability: higher means people are more likely to be harmed and slower to recover. Community resilience: lower means the community is less able to recover. High social vulnerability and low resilience both raise the NRI risk rating.

Supports FEMA checklist item B2-c: repetitive loss properties

Repetitive loss in this county, both definitions

Sources: 1, 4

DefinitionPropertiesSevere repetitive lossProperties
Repetitive loss, FMA definition (44 CFR 77.2)4Severe repetitive loss, FMA definition (44 CFR 77.2)26
Repetitive loss, NFIP insurance definition304Severe repetitive loss, NFIP insurance definition23

The state NFIP coordinator's list, the source FEMA's Handbook names, often uses the NFIP insurance definition (second row).

Repeat-flood properties: county and state-level rows

Sources: 1, 4

ScopeRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
County total426304233072107
of which: Sussex County (unincorporated area)21414413145146
of which: Lewes city0015015012
of which: Milford city0030300
of which: Millsboro town0010100
of which: Milton town0111101
of which: Ocean View town0010101
of which: Slaughter Beach town0020201
of which: South Bethany town0240141110
of which: Dewey Beach town0532532010
of which: Bethany Beach town0249249021
of which: Fenwick Island town2180902
of which: Rehoboth Beach city0181803
Statewide, no county in FEMA's file0010100

The statewide row counts properties FEMA's file gives with no county in this state; they are listed for reference and are not in this county's counts.

Repeat-flood properties by jurisdiction in the plan (NFIP community)

Sources: 1, 4

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredpropertiesNote
Sussex County10002921414413145146
Bethany Beach town1050830249249021
Bethel town1000550000000
Blades town1000310000000
Bridgeville town1000320000000
Dagsboro town1000330000000
Delmar town1000590000000
Dewey Beach town1000560532532010
Ellendale town1000600000000
Fenwick Island town1050842180902
Frankford town1000370000000
Georgetown town1000620000000
Greenwood town1000390000000
Henlopen Acres town1000530000000
Laurel town1000400000000
Lewes city1000410015015012
Milford city1000420272701Whole community, including the part in Kent County; in-county portion (county table): FMA RL 0, FMA SRL 0, NFIP RL 3, NFIP SRL 0, any category 3.
Millsboro town1000430010100
Millville town1000440000000
Milton town1000450111101
Ocean View town1000460010101
Rehoboth Beach city1050860181803
Seaford city1000480000000
Selbyville town1000380000000
Slaughter Beach town1000500020201
South Bethany town1000510240141110

Counts by occupancy group for each jurisdiction are in the Excel file, sheet "B2-c Jurisdictions".

Jurisdiction rows are whole NFIP communities and need not add up to the county total: a community that extends into another county is counted in full on each jurisdiction row, while the county table counts only its part in this county.

County repeat-flood properties by occupancy group

Sources: 1, 4

Occupancy groupRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
single-family residential31723414237281
2 to 4 unit residential121721703
other residential0539539020
non-residential021421403
not reported0000000

FEMA's occupancy groups have no institutional class; institutional properties are counted in non-residential or other residential in the table by occupancy group.

FMA RL and FMA SRL are the Flood Mitigation Assistance definitions (44 CFR 77.2), the ones the FEMA Local Mitigation Planning Policy Guide cites. NFIP repetitive loss (the FEMA insurance definition) is 2 or more claims over $1,000 in 10 years, and a property can leave that group once it is mitigated. Also shown: NFIP severe repetitive loss, any category, mitigated and currently insured. The Methods page gives the OpenFEMA field details.

Counts are aggregates of FEMA's public NFIP Multiple Loss Properties file (FEMA's data date 2026-08-02; file version 2026-08-04). No property is identified. County assignment is FEMA's geocode.

In this county 1 property is FMA repetitive loss but not NFIP repetitive loss, and 301 properties are NFIP repetitive loss but not FMA repetitive loss.

Exact counts; no count suppression.

Sources

Tables cite these sources by number. The full list, for the plan's bibliography (FEMA review item A4-a):

  1. FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
  2. FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
  3. FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
  4. FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
  5. FEMA, FEMA National Risk Index 1.20.0 (December 2025), county and census tract tables, version 1.20.0, pulled 2026-09-30, https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_Counties.zip (download, 25 MB), https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_CensusTracts.zip (download, 635 MB)
  6. NOAA NCEI, NOAA NCEI Storm Events Database, details files (csvfiles v1.0), version c20260918, pulled 2026-09-30, https://www.ncei.noaa.gov/pub/data/swdi/stormevents/csvfiles/
  7. NOAA National Weather Service, NWS county-public forecast zones correlation file, version bp03mr20 to bp16ap26 (11 files; newest bp16ap26), pulled 2026-09-30, https://www.weather.gov/gis/ZoneCounty
  8. U.S. Census Bureau, Census 2024 Gazetteer, 2020 place by county, CT county-to-cousub crosswalk, version 2024-gazetteer, pulled 2026-09-30, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_counties_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_cousubs_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_place_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_unsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_elsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_scsd_national.zip, https://www2.census.gov/geo/docs/reference/codes2020/national_place_by_county2020.txt, https://www2.census.gov/geo/docs/reference/ct_change/ct_cou_to_cousub_crosswalk.xlsx (used to match place names and codes; no table prints its values)

What this packet is and what the plan adds

This packet is the federal data for the plan's risk assessment (the summary on page 1 says how it is organized); the plan and FEMA's review decide whether each item is met.

The plan adds what only the community has: local data on assets, critical facilities, development and each jurisdiction's impacts; local hazard history, including state-declared emergencies; the mitigation strategy; and adoption.

How the federal data are built: National Risk Index values are FEMA's model, not counts of events. Storm Events is more complete from 1996; zone-level records are placed by forecast zone, not by location in the county. Public Assistance for a jurisdiction is matched by applicant name. The Methods page gives every rule and the known edge cases.

OpenFEMA disclaimer

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

Reuse, citation and corrections

Reuse and citation: Hazard Plain text and tables are licensed under Creative Commons Attribution 4.0 International (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); credit Hazard Plain and the release. The underlying federal data are public domain; OpenFEMA data are also subject to the OpenFEMA terms and conditions.

Cite this: Hazard Plain (2026). Sussex County, DE: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 10005). Automated baseline. https://hazardplain.org/de/10005/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Corrections: to report an error, name the packet, the table and what your records show. Contact: [email protected]