Anderson County, TN: risk-assessment baseline packet, release 2026-10

Summary

Plan status as of 2026-09-30: Approved, expires 2027-02-17. Plan: Anderson County (FEMA plan 107916), approved 2022-02-18.

Since the plan was approved on 2022-02-18: 3 new hazard declarations (2 incidents): EM-3625-TN (Severe Storms, Straight-Line Winds, Tornadoes, and Flooding), EM-3635-TN (Severe Winter Storm), DR-4898-TN (Severe Winter Storm).

NOAA Storm Events records since that date: 40 records (data through 2026-06-30).

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($16,268,806 a year), Tornado ($3,637,451) and Cold Wave ($3,442,700).

Repetitive-loss flood properties now: FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 4.

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.

Terms used

EAL:: expected annual loss: FEMA's modeled average yearly loss from a hazard.
NRI:: FEMA's National Risk Index (version 1.20, December 2025).
NFIP:: National Flood Insurance Program.
RL, SRL:: repetitive loss and severe repetitive loss: flood-insured properties with repeated claims (definitions in B2-c).
FMA, HMGP:: Flood Mitigation Assistance and Hazard Mitigation Grant Program, FEMA mitigation grants.
PA:: FEMA Public Assistance: disaster aid to governments and some nonprofits.
Zone-level:: NOAA logged the event for a National Weather Service forecast zone, which may include parts of neighboring counties.
County-coded:: NOAA logged the event to this county.
FIPS:: the federal code for a place; 47001 is this area.
D0 to D4:: U.S. Drought Monitor categories, from abnormally dry (D0) to exceptional drought (D4).
F/EF, EFU:: Fujita and Enhanced Fujita tornado ratings; EFU is an unrated tornado.
kt, CONUS:: knots (1 kt is about 1.15 mph); the contiguous United States.
CFR:: Code of Federal Regulations.
A4-a, E1-a:: other items of FEMA's Local Mitigation Plan Review Tool (sources, and changes since the last plan).
Dollars:: nominal (as reported, labeled with the year), not adjusted for inflation.

Plan clock

Status:: Approved, expires 2027-02-17
Plan:: Anderson County (FEMA plan 107916)
Approved:: 2022-02-18
Days to expiry:: 140
Update underway:: none recorded in FEMA's plan tracker

What changed since your last plan (approved 2022-02-18)

New federal declarations:: 3 new hazard declarations (2 incidents): EM-3625-TN (Severe Storms, Straight-Line Winds, Tornadoes, and Flooding), EM-3635-TN (Severe Winter Storm), DR-4898-TN (Severe Winter Storm)
Storm Events records since approval:: 40 records (data through 2026-06-30)
Repetitive loss now:: FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 4
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

Source: 1

Jurisdiction	Type	Status	Plan	Approved	Expires	Days to expirynegative = days since expiry	Notes
Anderson County (unincorporated area)	Unincorporated	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2022-02-24
Clinton city	City	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140
Norris city	City	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140
Oak Ridge city	City	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2022-02-22
Oliver Springs town	Town	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2022-03-03
Rocky Top city	Town	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140
Anderson County School District	School/School District	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2025-07-09
Clinton City School District	School/School District	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2025-06-10
Oak Ridge City School District	School/School District	Approved, expires 2027-02-17	Anderson County (FEMA plan 107916)	2022-02-18	2027-02-17	140	this jurisdiction approved 2025-06-10

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

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 EAL	Hazard	NRI risk rating	EAL rating	EAL buildingsmodeled dollars per year	EAL agriculturemodeled dollars per year	Cost of expected deaths and injuriesFEMA's dollar value per year, not property damage	EAL total (see note)modeled dollars per year	Storm Events records, 1996 to 2026-06-30count	Storm Events coverage note
1	Inland Flooding	Relatively Moderate	Relatively Moderate	$15,492,368	$3,800	$772,638	$16,268,806	40
2	Tornado	Relatively Moderate	Relatively Moderate	$1,492,591	$188	$2,144,673	$3,637,451	2
3	Cold Wave	Relatively Moderate	Relatively Moderate	$7,954	$3,530	$3,431,217	$3,442,700	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).
4	Earthquake	Relatively Low	Relatively Moderate	$2,421,715	n/a	$1,008,984	$3,430,700		Storm Events does not record earthquakes.
5	Strong Wind	Relatively Moderate	Relatively Moderate	$116,572	$19,116	$855,271	$990,960	203	Includes 3 High Wind and 2 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
6	Lightning	Relatively Moderate	Relatively Moderate	$58,386	n/a	$554,641	$613,027	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).
7	Hail	Relatively Low	Relatively Low	$327,820	$2,598	$61,066	$391,484	69
8	Ice Storm	Relatively Moderate	Relatively Moderate	$161,839	n/a	$20,321	$182,160	4
9	Winter Weather	Relatively Moderate	Relatively Moderate	$90,274	under $1	$69,545	$159,819	31
10	Heat Wave	Very Low	Very Low	$9	$1	$149,374	$149,384	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).
11	Landslide	Relatively Moderate	Relatively Low	$39,328	n/a	$31,458	$70,786	0	Declared 1 time; no Storm Events record of this type.
12	Hurricane	Very Low	Very Low	$56,150	$823	$2,009	$58,982	1
13	Wildfire	Very Low	Very Low	$36,746	$16	$18,881	$55,643	0	Declared 1 time; no Storm Events record of this type.
14	Drought	Very Low	Very Low	n/a	$8,635	n/a	$8,635	1

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 lightning, landslide and wildfire records (Storm Events records these hazards only in part).

Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: avalanche, coastal flooding, tsunami 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.

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

Hazard	Highest-rated census tractsNRI risk rating, score 0 to 100
Earthquake	tract 212.02 (Relatively High, 88.8); tract 202.02 (Relatively Moderate, 87.7); tract 201 (Relatively Moderate, 83.3)
Hurricane	tract 212.02 (Relatively Low, 52.3); tract 202.02 (Very Low, 50.0); tract 209.02 (Very Low, 48.7)
Landslide	tract 207 (Relatively Moderate, 98.6); tract 209.01 (Relatively Moderate, 98.4); tract 212.01 (Relatively Moderate, 97.6)
Tornado	tract 212.02 (Very High, 94.1); tract 209.02 (Relatively High, 89.6); tract 202.02 (Relatively High, 89.4)
Wildfire	tract 209.01 (Relatively Low, 86.4); tract 209.02 (Relatively Low, 82.8); tract 208 (Relatively Low, 82.6)

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 212.02 is Census Tract 212.02). 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

Hazard	Scale	Recordscount and years	Observed range	Worst recorded event	Most damaging (when different)	How it applies to jurisdictions	Note
Cold/Wind Chill, Extreme Cold/Wind Chill	wind chill	0					Wind chill: in event narratives only (local data needed).
Frost/Freeze (outside NRI's Cold Wave definition)	crop damage	0					Temperature: in event narratives only (local data needed).
Drought	U.S. Drought Monitor scale (D0 to D4)	1 record, 1998 (1 zone-level)	30 days; 1 with a recorded value	30 days (1 month), 1998-09-01 to 1998-09-30, zone-level		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.
Earthquake	Modified Mercalli (local data)	0					Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail	hail size (inches)	86 records, 1959 to 2025	0.75 in to 3.5 in (median 1 in); 86 with a recorded value	3.5 in hail, 1993-02-21	Hail, 1995-05-18, $500,000 property; crops not recorded (1995 dollars)	Event records naming jurisdictions in the plan: Oak Ridge city (28 records), Clinton city (17 records), Norris city (8 records), Oliver Springs town (3 records).
Excessive Heat, Heat	heat index (in event narratives)	0					Heat index: in event narratives only (local data needed).
Hurricane, Tropical Storm, Tropical Depression	Saffir-Simpson	1 record, 2004 (1 zone-level)		Strongest recorded: Tropical Storm record, 2004-09-16 to 2004-09-17, $15,000 property; crops not reported (2004 dollars); NWS zone TNZ036		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 Storm	Sperry-Piltz ice scale (local data)	4 records, 1998 to 2014 (4 zone-level)		Ice Storm, 2010-12-16, $20,000 property; $0 crops (2010 dollars); NWS zone TNZ036		Countywide (zone-level records).	Ice thickness: in event narratives only (local data needed).
Flash Flood, Flood, Lakeshore Flood	damage and flood days (flood depth: FIRM)	40 records, 1996 to 2026 (4 zone-level)		Flood, 2019-02-23, $600,000 property; $0 crops (2019 dollars)		Event records naming jurisdictions in the plan: Clinton city (10 records), Norris city (2 records), Oak Ridge city (2 records), Oliver Springs town (2 records). Zone-level records (4) 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 Flow	none (count and damage only)	0					Physical measure: in event narratives only (local data needed).
Lightning	annualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)	0					Storm Events lists lightning with damage or casualties; physical measure in event narratives only (local data needed).
High Wind and Strong Wind (outside NRI's Strong Wind definition)	wind speed (kt and mph)	5 records, 2003 to 2022 (5 zone-level)	40 kt (46 mph) to 66 kt (76 mph) (median 51 kt (59 mph)); 5 with a recorded value	66 kt (76 mph) measured gust, High Wind, 2016-03-30; NWS zone TNZ036	High Wind, 2006-12-01, $30,000 property; $0 crops, reported for the zone (2006 dollars)	Countywide (zone-level records).
Thunderstorm Wind	wind speed (kt and mph)	238 records, 1956 to 2024	40 kt (46 mph) to 100 kt (115 mph) (median 55 kt (63 mph)); 150 with a recorded value	100 kt (115 mph), measurement type not recorded, Thunderstorm Wind, 1999-05-07	Thunderstorm Wind, 2009-07-05, $100,000 property; $0 crops (2009 dollars)	Event records naming jurisdictions in the plan: Clinton city (39 records), Oak Ridge city (36 records), Norris city (13 records), Oliver Springs town (4 records).
Tornado	Enhanced Fujita (Fujita before Feb 2007)	4 records, 1953 to 2011	F/EF0 to F/EF2 (median between F/EF1 and F/EF2); 4 with a recorded value	F2 tornado, 2002-11-10, 5.5 mi within this county, 75 yd wide, $213,000 property; crops not reported (2002 dollars)		Event records naming jurisdictions in the plan: Oak Ridge city (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).
Wildfire	acres burned (local data)	0					Acres burned: in event narratives only (local data needed).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleet	none in data (snowfall: local data)	31 records, 1996 to 2026 (31 zone-level)		No damage reported in 31 records.		Countywide (zone-level records).	Snow depth: in event narratives only (local data needed).

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records whose zone 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: 22 declarations covering 18 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

Declared	Incident began	FEMA number	Type	Title	Mapped hazard	County Public Assistancefederal share obligated, nominal dollars	Flags	Notes
2026-02-06	2026-01-22	DR-4898-TN	Major disaster	Severe Winter Storm	Winter Weather	$12,563.05	new since last plan; within last 5 years
2026-01-24	2026-01-22	EM-3635-TN	Emergency	Severe Winter Storm	Winter Weather	no Public Assistance recorded	new since last plan; within last 5 years	same incident as DR-4898
2025-04-02	2025-04-02	EM-3625-TN	Emergency	Severe Storms, Straight-Line Winds, Tornadoes, and Flooding	Inland Flooding; Strong Wind; Tornado	no Public Assistance recorded	new since last plan; within last 5 years
2020-04-02	2020-01-20	DR-4514-TN	Major disaster	COVID-19 Pandemic	Non-natural, not counted	$193,977.18
2020-03-13	2020-01-20	EM-3473-TN	Emergency	COVID-19	Non-natural, not counted	no Public Assistance recorded		same incident as DR-4514
2019-04-17	2019-02-19	DR-4427-TN	Major disaster	Severe Storms, Flooding, Landslides, and Mudslides	Inland Flooding (primary); also designated: Landslide	$393,410.59
2015-04-02	2015-02-15	DR-4211-TN	Major disaster	Severe Winter Storm and Flooding	Ice Storm	$183,766.74
2014-08-13	2014-06-05	DR-4189-TN	Major disaster	Severe Storms, Tornadoes, Straight-Line Winds, and Flooding	Inland Flooding; Strong Wind; Tornado	$737,421.14
2011-07-20	2011-06-18	DR-4005-TN	Major disaster	Severe Storms, Straight-Line Winds, Tornadoes, and	Strong Wind; Tornado	$163,547.03
2005-09-05	2005-08-29	EM-3217-TN	Emergency	Hurricane Katrina Evacuation	Hurricane: evacuation support, not a local hazard event; not counted	no Public Assistance recorded
2003-05-08	2003-05-04	DR-1464-TN	Major disaster	Severe Storms, Tornadoes, and Flooding	Inland Flooding; Tornado	none placed in this county by FEMA's record; $6,166.94 for this declaration is not placed in any county (see the state page)
2003-03-20	2003-02-14	DR-1456-TN	Major disaster	Severe Storms and Flooding	Inland Flooding	$296,146.02
2002-11-13	2002-11-09	DR-1441-TN	Major disaster	Severe Storms and Tornados	Tornado	$202,008.91
2002-04-05	2002-01-23	DR-1408-TN	Major disaster	Severe Storms and Flooding	Inland Flooding	$61,420.09
2000-11-02	2000-10-30	FM-2346-TN	Fire management	Tn - Knoxville Fire Complex - 11/02/00	Wildfire	no Public Assistance recorded
2000-06-12	2000-05-23	DR-1331-TN	Major disaster	Severe Storms, Tornadoes, and Flooding	Inland Flooding; Tornado	$132,238.95
1999-01-15	1998-12-23	DR-1260-TN	Major disaster	Severe Winter Storm	Winter Weather	$243,080.11
1998-04-20	1998-04-16	DR-1215-TN	Major disaster	Severe Storms, Tornadoes and Flooding	Inland Flooding; Tornado	no Public Assistance recorded
1993-03-14	1993-03-13	EM-3095-TN	Emergency	Severe Snowfall, Winter Storm	Winter Weather	no Public Assistance recorded
1991-01-04	1990-12-19	DR-889-TN	Major disaster	Severe Storms & Flooding	Inland Flooding	PA not declared for this county
1977-04-29	1977-04-29	DR-533-TN	Major disaster	Severe Storms & Flooding	Inland Flooding	no Public Assistance recorded
1973-03-21	1973-03-21	DR-366-TN	Major disaster	Heavy Rains & Flooding	Inland Flooding	no 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

Declared	Incident began	FEMA number	Type	Title	Mapped hazard
1963-03-27	1963-03-27	DR-151-TN	Major disaster	Severe Storms & Flooding	Inland 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.

Public Assistance filed under this county for declarations that do not list it: 1 row, $13,581.10

Sources: 2, 3

FEMA number	Declared	Title	Applicant	PA obligatedfederal share obligated, nominal dollars
DR-4320-TN	2017-06-23	Severe Storms, Straight-Line Winds, and Flooding	Clinton Utilities Board	$13,581.10

FEMA's Public Assistance summaries file these applicants under this county, but FEMA's declaration rows for these disasters do not designate it (an electric cooperative or district serving several counties, for example). Not in any declaration row above and not counted.

Public Assistance not placed in any Tennessee county: 5 rows, $12,113,670.26; listed on the Tennessee state page.

Source: 3

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

Hazard	Storm Events records, all years on file(years in the Period column)	Since plan approvalrecords	In the 12 months before plan approvalrecords	Last 5 yearsrecords	Declared incidents, all yearsseparate disasters	Declared since approvalseparate disasters	Period	Statement
Cold Wave	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Drought	1	0	0	0	0	0	1996 to 2026-06-30
Earthquake	0	0	0	0	0	0		Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail	86	13	0	13	0	0	1955 to 2026-06-30
Heat Wave	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Hurricane	1	0	0	0	0	0	1996 to 2026-06-30
Ice Storm	4	0	0	0	1	0	1996 to 2026-06-30
Inland Flooding	40	10	0	10	11	1	1996 to 2026-06-30
Landslide	0	0	0	0	1	0	1996 to 2026-06-30	No Storm Events records of this type; 1 federal declared incident (see declarations table)
Lightning	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Strong Wind	243	12	4	12	3	1	1955 to 2026-06-30	Includes 3 High Wind and 2 Strong Wind records.
Tornado	4	0	0	0	7	1	1950 to 2026-06-30
Wildfire	0	0	0	0	1	0	1996 to 2026-06-30	No Storm Events records of this type; 1 federal declared incident (see declarations table)
Winter Weather	31	5	0	5	3	1	1996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

Date	Event type	Magnitude or extent	Damagenominal dollars	Deaths, injuriesdirect only	Location	Why listed
2019-04-14	Thunderstorm Wind	50 kt (58 mph) estimated gust	damage not reported	0, 1	BATLEY	deaths or injuries recorded
2019-02-23	Flood		$600,000 property; $0 crops (2019 dollars)	0, 0	NORRIS	B1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2016-03-30	High Wind	66 kt (76 mph) measured gust	damage not reported	0, 0	NWS zone TNZ036 (ANDERSON), zone-level	B1-c worst recorded: High Wind and Strong Wind
2010-12-16	Ice Storm		$20,000 property; $0 crops, reported for the zone (2010 dollars)	0, 0	NWS zone TNZ036 (ANDERSON), zone-level	B1-c worst recorded: Ice Storm
2006-12-01	High Wind	60 kt (69 mph) estimated gust	$30,000 property; $0 crops, reported for the zone (2006 dollars)	0, 0	NWS zone TNZ036 (ANDERSON), zone-level	B1-c most damaging: High Wind and Strong Wind
2004-09-16	Tropical Storm		$15,000 property; crops not reported, reported for the zone (2004 dollars)	0, 0	NWS zone TNZ036 (ANDERSON), zone-level	B1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression
2002-11-10	Tornado	F2, 5.5 mi within this county, 75 yd wide	$213,000 property; crops not reported (2002 dollars)	0, 0	LAKE CITY	B1-c worst recorded: Tornado
1999-05-07	Thunderstorm Wind	100 kt (115 mph), measurement type not recorded	damage not reported	0, 0	CLAXTON	B1-c worst recorded: Thunderstorm Wind
1998-09-01	Drought		damage not reported	0, 0	NWS zone TNZ036 (ANDERSON), zone-level	B1-c worst recorded: Drought
1998-04-17	Flash Flood		damage not reported	1, 0	LAKE CITY	deaths or injuries recorded
1995-05-18	Hail	2.75 in	$500,000 property; crops not recorded (1995 dollars)	0, 9	Clinton to Oak Ridge	deaths or injuries recorded
1993-02-21	Hail	3.5 in	$500 property; crops not recorded (1993 dollars)	0, 0	Oak Ridge	B1-c worst recorded: Hail

The full list is in the Excel file, sheet "B1-d Storm Events history" (410 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

Hazard	FEMA annualized frequency (modeled)unit per row	Unit	In plain terms	Descriptor	Descriptor basis	NRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)	NRI period	Location	Note
Cold Wave	0.789	event-days per year	about 0.789 days per year		event-days in 0 of 30 years, 1996 to 2025 (0%)	15	2005-11-12 to 2024-11-12 (19 years)	countywide	No Storm Events cold wave record, 1996 to 2025.
Drought	17.5	event-days per year	about 17.5 days per year	Possible (from Storm Events: 1 of 30 years)	event-days in 1 of 30 years, 1996 to 2025 (3.33%)	553	2000 to 2025 (25.25 years; D3 and D4 only)	countywide
Earthquake	0.00397	annual probability at a location	chance a given location in the county has at least minor-damage shaking in a year: 0.397%			not shown	modeled	see B1-f	No descriptor (Storm Events does not record earthquakes).
Hail	2.96	events per year	about 2.96 per year	Highly likely	FEMA annualized frequency (modeled)	112.5 (modeled)	1986 to 2023 (38 years)	countywide
Heat Wave	0.842	event-days per year	about 0.842 days per year		event-days in 0 of 30 years, 1996 to 2025 (0%)	15	2005-11-12 to 2024-11-12 (19 years)	countywide	No Storm Events heat wave record, 1996 to 2025
Hurricane	0.0173	events per year	about 1 in 58 years	Possible	FEMA annualized frequency (modeled)	3	1851 to 2024 (Atlantic)	see B1-f	NRI counts hurricane and tropical storm tracks passing within storm-force wind range; federal declarations are in B1-d.
Ice Storm	0.467	event-days per year	about 0.467 days per year	Likely (from Storm Events: 4 of 30 years)	event-days in 4 of 30 years, 1996 to 2025 (13.3%)	32	1946-12-31 to 2014-02-12 (67 years)	countywide
Inland Flooding	1.14	event-days per year	about 1.14 days per year	Likely (from Storm Events: 15 of 30 years)	event-days in 15 of 30 years, 1996 to 2025 (50%)	32	1996 to 2023 (28 years)	see B1-f
Landslide	1.35	events per year (modeled)	about 1.35 per year	Highly likely	FEMA annualized frequency (modeled)	not shown	modeled	see B1-f
Lightning	57	days per year with a strike	about 57 days per year	Highly likely	FEMA annualized frequency (modeled)	not shown	1995 to 2023 (29 years; CONUS)	countywide
Strong Wind	5.22	events per year	about 5.22 per year	Highly likely	FEMA annualized frequency (modeled)	199	1986 to 2023 (38 years)	countywide
Tornado	0.119	events per year	about 1 in 8 years	Likely	FEMA annualized frequency (modeled)	not shown	1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)	see B1-f
Wildfire	0.00274	annual probability at a location	chance a given location in the county burns in a year: 0.274%		Storm Events records in 0 of 30 years, 1996 to 2025 (0%)	not shown	modeled	see B1-f	No descriptor: no Storm Events record 1996 to 2025
Winter Weather	5.05	event-days per year	about 5.05 days per year	Likely (from Storm Events: 16 of 30 years)	event-days in 16 of 30 years, 1996 to 2025 (53.3%)	96	2005-11-12 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

Unit	Descriptor	Definition
events per year	Highly likely	1 or more per year
events per year	Likely	about once in 1 to 10 years
events per year	Possible	about once in 10 to 100 years
events per year	Unlikely	less than once in 100 years
annual probability	Likely	10% to under 100% chance in a given year
annual probability	Possible	1% to under 10% chance in a given year
annual probability	Unlikely	under 1% chance in a given year
event-days (share of years)	Highly likely	event-days recorded in 90% or more of years
event-days (share of years)	Likely	event-days recorded in 10% to under 90% of years
event-days (share of years)	Possible	event-days recorded in some years but under 10% of years
lightning strike-days	Highly likely	cloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

Hazard	Band	Years	Eventscounty-coded records	Years in period	Events per yearevents / years
Hail	1.00-1.99 in	1996 to 2025	42	30	1.4
Hail	2.00 in+	1996 to 2025	0	30	0
Thunderstorm Wind (counted as NRI Strong Wind)	50-64 kt	1996 to 2025	135	30	4.5
Thunderstorm Wind (counted as NRI Strong Wind)	65 kt+	1996 to 2025	10	30	0.333
Thunderstorm Wind (counted as NRI Strong Wind)	unmeasured or below 50 kt	1996 to 2025	53	30	1.77
Tornado	EF0-1	1996 to 2025	1	30	0.0333
Tornado	EF2-3	1996 to 2025	1	30	0.0333
Tornado	EF4-5	1996 to 2025	0	30	0
Tornado	unrated (EFU)	1996 to 2025	0	30	0

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

Hazard	Tractsrated of all	NRI risk score, 0 to 100			Tracts by rating
Hazard	Tractsrated of all	Min	Median	Max	Tracts by rating
Cold Wave	20 of 20	15.9	81.3	91.5	Relatively High 12, Relatively Moderate 7, Very Low 1
Drought	1 of 20	87.7	87.7	87.7	Relatively Low 1, No Rating 19
Earthquake	20 of 20	53.0	77.3	88.8	Relatively High 1, Relatively Moderate 9, Relatively Low 10
Hail	20 of 20	39.6	68.3	85.8	Relatively Moderate 9, Relatively Low 11
Heat Wave	20 of 20	1.4	10.1	21.0	Relatively Low 3, Very Low 17
Hurricane	20 of 20	31.5	42.7	52.3	Relatively Low 1, Very Low 19
Ice Storm	20 of 20	27.1	66.3	90.1	Relatively Moderate 8, Relatively Low 11, Very Low 1
Inland Flooding	20 of 20	1.1	64.5	97.9	Very High 1, Relatively High 6, Relatively Moderate 4, Relatively Low 8, Very Low 1
Landslide	20 of 20	79.2	93.1	98.6	Relatively Moderate 6, Relatively Low 11, Very Low 3
Lightning	20 of 20	3.8	83.2	95.1	Relatively High 12, Relatively Moderate 7, Very Low 1
Strong Wind	20 of 20	12.1	79.7	91.3	Relatively High 6, Relatively Moderate 13, Very Low 1
Tornado	20 of 20	29.9	72.7	94.1	Very High 1, Relatively High 7, Relatively Moderate 11, Relatively Low 1
Wildfire	20 of 20	23.6	70.8	86.4	Relatively Low 12, Very Low 8
Winter Weather	20 of 20	32.9	77.1	93.9	Relatively High 9, Relatively Moderate 10, Relatively 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.

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

Jurisdiction	Type	Plan status	Repetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definition	Public Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollars	Event records naming this placeall years; since its plan	Notes
Anderson County (unincorporated area)	Unincorporated	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 4	$645,153.86	0 total; 0 since its plan
Clinton city	City	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 0	$231,166.15	66 total; 3 since its plan	Includes $29,153.05 for declarations not counted as hazard incidents (DR-4514-TN).
Norris city	City	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 0	no Public Assistance recorded	23 total; 4 since its plan
Oak Ridge city	City	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 0	$540,929.94	67 total; 5 since its plan	Includes $24,925.99 for declarations not counted as hazard incidents (DR-4514-TN).
Oliver Springs town	Town	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 0	no Public Assistance recorded	9 total; 1 since its plan
Rocky Top city	Town	Approved, expires 2027-02-17	FMA RL 0, SRL 0; any 0	no Public Assistance recorded	0 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).

School districts and special districts get a plan clock row only.

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

Hazard	Building exposuremodeled dollars	Agriculture exposuremodeled dollars	Population exposedpeople	EAL buildingsmodeled dollars per year	EAL agriculturemodeled dollars per year	Cost of expected deaths and injuriesFEMA's dollar value per year, not property damage	EAL as % of exposurebuildings; agriculture where noted	Storm Events damage since 2022-02-18county-coded records, property plus crops, nominal dollars	Zone-level damage since planproperty plus crops, reported for the zone	Public Assistance since plannominal dollars; see note	Note
Cold Wave	$14,385,393,240	$5,555,168	77,015	$7,954	$3,530	$3,431,217	under 0.0001%
Drought	n/a	$1,638,242	n/a	n/a	$8,635	n/a	0.527% (agriculture)				NRI has no building exposure for this hazard; agriculture shown
Earthquake	$25,606,544,344	n/a	77,123	$2,421,715	n/a	$1,008,984	0.00946%
Hail	$14,385,397,607	$5,555,168	77,015	$327,820	$2,598	$61,066	0.00228%
Heat Wave	$14,385,393,240	$5,555,168	77,015	$9	$1	$149,374	under 0.0001%
Hurricane	$14,315,484,201	$5,463,982	76,561	$56,150	$823	$2,009	0.000392%
Ice Storm	$14,385,169,139	n/a	77,014	$161,839	n/a	$20,321	0.00113%
Inland Flooding	$14,366,412,108	$310,381	1,153	$15,492,368	$3,800	$772,638	n/a (see note)	$0		no Public Assistance recorded (1 declaration)	NRI 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	$1,436,916,185	n/a	9,995	$39,328	n/a	$31,458	0.00274%
Lightning	$14,385,397,607	n/a	77,015	$58,386	n/a	$554,641	0.000406%
Strong Wind	$14,385,397,607	$5,555,168	77,015	$116,572	$19,116	$855,271	0.00081%			no Public Assistance recorded (1 declaration)
Tornado	$14,385,397,607	$5,555,168	77,015	$1,492,591	$188	$2,144,673	0.0104%			no Public Assistance recorded (1 declaration)
Wildfire	$361,009,269	$712,021	5,645	$36,746	$16	$18,881	0.0102%
Winter Weather	$14,385,393,240	$5,555,168	77,015	$90,274	under $1	$69,545	0.000628%		$0	$12,563.05

Totals since 2022-02-18 (Storm Events through 2026-06-30): 34 county-coded records, 10 with a damage value recorded (including $0), $0; 6 zone-level records, 2 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: $12,563.05 on 3 counted declarations, 1 of them with Public Assistance.

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

Measure	Value
Population	77,015
Building value (total, not at risk)	$14,385,397,607
Agriculture value (total, not at risk)	$5,555,168
NRI risk rating (all hazards)	Relatively Low
Expected annual loss, buildings and agriculture, all hazards	$20,340,459
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)	$9,120,077
Social vulnerability rating	Relatively Moderate
Community resilience rating	Relatively Moderate
NRI version	December 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

Definition	Properties	Severe repetitive loss	Properties
Repetitive loss, FMA definition (44 CFR 77.2)	0	Severe repetitive loss, FMA definition (44 CFR 77.2)	0
Repetitive loss, NFIP insurance definition	4	Severe repetitive loss, NFIP insurance definition	0

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

Repeat-flood properties: county total and NFIP communities

Sources: 1, 4

Scope	RL, FMAproperties	SRL, FMAproperties	RL, NFIPproperties	SRL, NFIPproperties	Any categoryproperties	Mitigatedproperties	Currently insuredproperties
County total	0	0	4	0	4	0	1
of which: Anderson County (unincorporated area)	0	0	4	0	4	0	1

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

Sources: 1, 4

Jurisdiction	NFIP community ID	RL, NFIPproperties	Any categoryproperties	Currently insuredproperties
Anderson County (unincorporated area)	470217	4	4	1
Clinton city	470001	0	0	0
Norris city	470003	0	0	0
Oak Ridge city	475441	0	0	0
Oliver Springs town	470005	0	0	0
Rocky Top city	475436	0	0	0

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 group	RL, NFIPproperties	Any categoryproperties	Currently insuredproperties
single-family residential	4	4	1
2 to 4 unit residential	0	0	0
other residential	0	0	0
non-residential	0	0	0
not reported	0	0	0

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 0 properties are FMA repetitive loss but not NFIP repetitive loss, and 4 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):

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)

What this packet is and what the plan adds

This packet is the federal data for the plan's risk assessment, organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B. Each section heading names the item its tables support; the plan and FEMA's review decide whether the 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). Anderson County, TN: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 47001). Automated baseline. https://hazardplain.org/tn/47001/ 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]

Hazard Plain release 2026-10. As of 2026-09-30; Storm Events data through 2026-06-30. Automated baseline.