Delaware County, PA

Name: Delaware County, Pennsylvania: risk-assessment baseline packet, release 2026-10
Creator: Hazard Plain

Risk-assessment baseline packet. County FIPS 42045. Release 2026-10, data as of 2026-09-30.

Summary

Plan status as of 2026-09-30: No county-level plan row in FEMA data.

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($73,868,895 a year), Earthquake ($13,263,729) and Heat Wave ($12,832,470).

The packet's tables are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); the summaries below follow the same order.

Download the packet

Full packet as a web page. File manifest (checksums, source versions).

Plan clock

No county-level plan row in FEMA data

What changed since your last plan

No county-level plan row in FEMA data, so there is no approval date to count from.

Plan status for every jurisdiction listed in this county

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

Jurisdiction	Type	Status	Plan	Approved	Expires	Days to expirynegative = days since expiry	Update underway	Notes
Aldan borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Brookhaven borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-05-01
Chester city	City	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-08
Chester Heights borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-06
Clifton Heights borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Collingdale borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Colwyn borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Darby borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-15
East Lansdowne borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Eddystone borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Folcroft borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Glenolden borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Lansdowne borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2024-09-04
Marcus Hook borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-06
Media borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-05-18
Millbourne borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Morton borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Norwood borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Parkside borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Prospect Park borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-14
Ridley Park borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Rose Valley borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Rutledge borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Sharon Hill borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Swarthmore borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Trainer borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Upland borough	Organized Borough	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-14
Yeadon borough	Organized Borough	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Aston township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-05-17
Bethel township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-04-03
Chadds Ford township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2024-04-03
Chester township	Township	Plan 108724 approved 2023-02-27, pending adoption here; not yet eligible	Delaware County Hazard Mitigation Plan (FEMA plan 108724), pending adoption here	2023-02-27 by FEMA; not yet adopted here	2028-02-26 once adopted		FEMA tracker shows a plan approvable pending adoption	Not yet eligible: adopt the approved plan.
Concord township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-07
Darby township	Township	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Edgmont township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2024-04-09
Haverford township	Township	Plan 108724 approved 2023-02-27, pending adoption here; not yet eligible	Delaware County Hazard Mitigation Plan (FEMA plan 108724), pending adoption here	2023-02-27 by FEMA; not yet adopted here	2028-02-26 once adopted		FEMA tracker shows a plan approvable pending adoption	Not yet eligible: adopt the approved plan.
Lower Chichester township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2024-01-02
Marple township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-13
Middletown township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress
Nether Providence township	Township	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Newtown township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress
Radnor township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-04-24
Ridley township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-22
Springfield township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-07-11
Thornbury township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-01
Tinicum township	Township	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Upper Chichester township	Township	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-09
Upper Darby township	Township	No approved plan on record	none	none	none		FEMA tracker shows a plan in progress
Upper Providence township	Township	Plan 108724 approved 2023-02-27, pending adoption here; not yet eligible	Delaware County Hazard Mitigation Plan (FEMA plan 108724), pending adoption here	2023-02-27 by FEMA; not yet adopted here	2028-02-26 once adopted		FEMA tracker shows a plan approvable pending adoption	Not yet eligible: adopt the approved plan.
Brandywine Conservancy & Museum Special District	Special District	Approved, expires 2028-02-26	Delaware County Hazard Mitigation Plan (FEMA plan 108724)	2023-02-27	2028-02-26	514	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-13

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. Full tables are in the downloads above.

Supports FEMA checklist item B1-a Hazard identification

17 of the 18 National Risk Index hazards apply here.

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

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

Not covered by NRI (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 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

Avalanche, Earthquake, Hurricane, Landslide, Tornado, Tsunami and Wildfire vary within the county; the packet lists the highest-rated census tracts for each.
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 county; national data give no location within it.

Supports FEMA checklist item B1-c Hazard extent

Storm Events records for 15 of the 20 NOAA event-type groups mapped to the 18 hazards, with the scale, observed range and worst recorded event for each; the others say which local data are needed.

Worst recorded tornado, hail and thunderstorm wind (the three event types on record since the 1950s; the packet has every group):

Hail: 1.75 in hail, 2010-06-24; same size also recorded on 1992-07-10, 2009-03-29
Thunderstorm Wind: 91 kt (105 mph) estimated gust, Thunderstorm Wind, 2025-04-04
Tornado: EF2 tornado, 2019-10-31, 0.47 mi within this county, 250 yd wide, damage not reported, 2 direct injuries

Supports FEMA checklist item B1-d Previous occurrences

Federal declarations for this area: 24 declarations covering 18 separate hazard incidents counted in this packet; each with type, dates and county Public Assistance dollars.

No county-level plan row in FEMA data, so there is no approval date to count from.

6 statewide declarations listed separately.

Hazards with no Storm Events record and no federal declaration are stated as such (5 of 18).

Storm Events history: 1,256 records (notable ones in the PDF, all of them in the Excel file).

Supports FEMA checklist item B1-e Probability of future events

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, Landslide and Wildfire
Possible: Avalanche, Hurricane, Ice Storm and Tornado

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

Supports FEMA checklist item B1-f Hazards that vary across jurisdictions

Range of census tract risk scores within the area for 17 of the 18 hazards (152 tracts; rated tracts only).

49 jurisdictions: plan clock, repeat-flood count, Public Assistance dollars and event records naming the place (starting figures from federal data).

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

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

No county-level plan row in FEMA data, so there is no approval date to count from.

Local data needed

To gather:

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

Supports FEMA checklist item B2-a Vulnerability (county context)

Population 576,366; building value $133,367,188,695 and agriculture value $12,224,902 (total, not at risk).

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

Supports FEMA checklist item B2-c Repetitive loss properties

Repetitive-loss properties, FMA definition (44 CFR 77.2): 12 repetitive loss, 90 severe repetitive loss. NFIP insurance definition: 335 and 89.

Mitigated 1; insured 117; NFIP data as of 2026-08-02. Counts by occupancy group and for each jurisdiction are in the packet.

Releases

2026-10 (this release)

Each release is dated; this is release 2026-10. It was first published 2026-09-30; its files do not change. Later releases will be listed here with what changed between them. All releases.

Cite this

Hazard Plain (2026). Delaware County, PA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 42045). Automated baseline. https://hazardplain.org/pa/42045/ 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)

FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
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)
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/
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
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)

How this packet is built: methods and sources