Reference
Clear definitions for the terms used across this site. If we use a word you do not know, it is defined here.
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A pre-packed bag containing essential supplies for at least 72 hours, ready to grab during an evacuation. Commonly called a go-bag; New World Survival uses the term 72-hour bag. It typically includes water, food, medications, documents, a flashlight, a battery-powered radio, cash, and a change of clothes. Evacuation decisions happen fast, and having a bag ready eliminates the scramble to gather supplies under stress.
Related: evacuation order
The national emergency telephone number that connects callers to local police, fire, and EMS dispatch. The 911 system depends on telecommunications infrastructure — cell towers, telephone switches, and dispatch center equipment — all of which can fail during major disasters. During the 2021 Texas grid collapse, some 911 centers lost power and reverted to backup systems with reduced capacity.
Related: Emergency Alert System (EAS), Wireless Emergency Alert (WEA)
A
A structured review document produced after a disaster or emergency exercise that evaluates what happened, what worked, what failed, and what should change. AARs are the primary mechanism by which emergency management learns from events. They are the most reliable source for understanding disaster response decisions and outcomes.
Related: Incident Command System (ICS), Federal Emergency Management Agency (FEMA), Emergency Operations Center (EOC)
The power and confidence to act on your own decisions rather than waiting for instructions or rescue. Agency is the central outcome of all preparedness work: a person with a plan, supplies, skills, and practiced routines does not need to be told what to do when conditions change. Building agency is the reason NWS exists.
Related: Autonomy, Capability, Fortitude
A licensed radio communication system that operates independently of cell towers, internet, and commercial infrastructure. During disasters that knock out normal communications, ham radio operators provide emergency message relay, damage reports, and coordination support. Earning a Technician-class license requires passing a 35-question FCC exam — no Morse code required.
Related: American Radio Relay League (ARRL), Community Emergency Response Team (CERT), SKYWARN, Amateur Radio Emergency Service (ARES)
A volunteer program organized by the ARRL in which licensed amateur radio operators provide emergency communications during disasters. ARES groups coordinate with local emergency management agencies and activate when normal communications are disrupted. Membership requires only an amateur radio license and willingness to train.
Related: ham radio, American Radio Relay League (ARRL), Community Emergency Response Team (CERT)
An unfinished WPA Federal Writers' Project initiative (late 1930s–1941) that set out to document American food traditions region by region. Writers across the country produced essays on local foodways, community meals, ethnic food traditions, and seasonal customs before the project was abandoned when the U.S. entered World War II. Over 200,000 pages of manuscript survive and are a primary source for regional foodways research.
Related: Works Progress Administration (WPA), Federal Writers Project
The national membership organization for amateur radio operators in the United States, founded in 1914. ARRL provides licensing exam resources, emergency communication training, and a nationwide network of local radio clubs. The ARRL section finder is the fastest way to locate a ham radio club in your area.
Related: ham radio, Amateur Radio Emergency Service (ARES), Community Emergency Response Team (CERT)
The nonprofit humanitarian organization that provides emergency shelter, food, and health services during and after disasters in the United States. Red Cross volunteers staff shelters, distribute supplies, and provide mental health support. The organization also offers first aid, CPR, and water safety training courses that are widely recognized as baseline certifications.
Related: Community Emergency Response Team (CERT), first aid
The professional organization for civil engineers in the United States, which publishes the Infrastructure Report Card — a quadrennial assessment grading the condition of U.S. infrastructure across 17 categories. ASCE grades are widely cited in policy discussions and provide the most comprehensive public assessment of infrastructure condition. The most recent report card gave U.S. infrastructure an overall grade of C-minus.
Related: design basis, building code, Levee, water main
The fictional persona — Uncle Sam's wife — who hosted the USDA's 'Housekeepers' Chats' radio program from 1926 to 1946. Local actresses read USDA-supplied scripts featuring practical cooking advice, household tips, and economical recipes to millions of listeners. The compiled recipe books from the program are among the most widely distributed government publications of the 20th century.
Related: Bureau of Home Economics, Hazel Stiebeling
The ability to operate independently and make decisions without relying on external systems or approval. In preparedness, autonomy means a household can sustain itself when supply chains, utilities, or services are interrupted. Autonomy is not isolation; it is the capacity to function on your own terms when needed.
Related: Independence, Self-Sufficiency, Agency
B
A plumbing device that allows water to flow in one direction only, preventing contaminated water from flowing backward into the clean supply. Building codes require backflow prevention on any connection between a potable water line and a non-potable source, including inline water storage systems.
Related: Distribution System, Potable Water
A filter maintenance technique that reverses the direction of water flow through a filter element to clear trapped particles and restore flow rate. For hollow fiber membrane filters like the Sawyer Squeeze, backflushing uses clean water pushed through the output end of the filter to dislodge debris caught in the pores. Regular backflushing extends filter life and maintains filtration performance.
Related: Hollow Fiber Membrane, Micron
A volunteer who serves as the primary point of contact for emergency communication and coordination on a single block or small neighborhood area. Block captains maintain the communication tree, keep the neighborhood contact sheet current, and serve as the liaison to local emergency management during events. The role requires no formal training — just willingness to organize and a current contact list.
Related: communication tree, Map Your Neighborhood, Community Emergency Response Team (CERT)
A public health notice issued when a water system may have been contaminated — typically after a main break, treatment plant failure, or natural disaster. The advisory means tap water should be brought to a rolling boil for at least one minute before drinking, cooking, or brushing teeth. Boil advisories are issued by local water utilities or health departments and remain in effect until testing confirms the water is safe.
Related: water main
A rare but severe form of food poisoning caused by a toxin produced by the bacterium Clostridium botulinum, which thrives in low-oxygen, low-acid environments like improperly canned food. The toxin attacks the nervous system and can be fatal even in small amounts. Proper pressure canning temperatures and times are the primary defense against botulism in home-preserved food.
Related: pressure canner, National Center for Home Food Preservation (NCHFP)
A set of regulations governing the design, construction, and maintenance of buildings to ensure safety and structural integrity. Building codes are adopted and enforced at the state or local level, which means protection standards vary significantly by jurisdiction. Major disasters frequently lead to code revisions — the Camp Fire prompted California to adopt the most stringent WUI building codes in the country.
Related: design basis, structural assessment, Wildland-Urban Interface (WUI)
The sealed opening on a storage drum, closed with a threaded plug and tightened with a bung wrench. Standard 55-gallon water drums have two bung openings, one 2-inch (NPS) and one 3/4-inch. Pumps, spigots, and siphon tubes thread into the larger bung for filling and dispensing.
Related: HDPE (High-Density Polyethylene), Water Storage
A division of the U.S. Department of Agriculture that operated from 1923 to 1962, producing practical, tested guidance on cooking, nutrition, household management, food preservation, and textile care for American families. The Bureau's Depression-era bulletins — written primarily by women scientists — are the foundational source material for the NWS Heritage content series. All Bureau publications are U.S. government works and fully in the public domain.
Related: Aunt Sammy, Hazel Stiebeling, Works Progress Administration (WPA), Federal Writers Project
C
Having the skills, knowledge, tools, and resources to act effectively when needed. Capability is broader than equipment: a household with a generator but no knowledge of safe operation has equipment, not capability. NWS content is organized around building real capability across twelve self-reliance domains.
Related: Readiness, Resourcefulness, Fieldcraft
A colorless, odorless gas produced by burning fuel — gasoline, propane, natural gas, wood, charcoal — in enclosed or poorly ventilated spaces. Carbon monoxide poisoning is one of the leading causes of death after disasters, primarily from generators, grills, and camp stoves used indoors during power outages. Every household should have battery-operated CO detectors on every floor.
Related: portable generator
A sequence of failures in an interconnected system where the failure of one component triggers failures in others, often accelerating beyond the system's ability to recover. The 2003 Northeast blackout is a classic example — a software bug and untrimmed trees in Ohio initiated a chain of relay failures that blacked out 55 million people across eight states and Canada. Cascading failures are the primary way that infrastructure systems experience catastrophic events.
Related: power grid, design basis
The concentration of chlorine remaining in treated water after initial disinfection. Municipal water plants add chlorine to kill pathogens, and the residual that remains in the water continues to suppress bacterial growth during storage. As the residual dissipates over time, stored water becomes more vulnerable to contamination.
Related: Potable Water, Shelf Life, Water Preserver Concentrate
A self-cleaning intake screen made of inclined wedge wire, angled so that fast-moving flow crossing the surface has thin layers sheared off the bottom and directed through the slots while debris and fish carry on over the panel. The Bureau of Reclamation describes these screens as hydraulically self-cleaning with no moving parts, which suits them to remote sites with no electrical power.
Related: Trash Rack, Forebay, Penstock
The unbroken series of refrigerated storage and transportation steps that keeps perishable food at safe temperatures from production to consumption. A break in the cold chain — a power outage at a warehouse, a refrigerated truck breakdown, a grocery store losing power — can render large quantities of food unsafe. Most consumers interact with the cold chain only when their own refrigerator loses power.
Related: just-in-time inventory
A structured system in which one person contacts two or three others, who each contact two or three more, rapidly spreading information through a network without requiring a single point of contact to reach everyone. Communication trees are the most reliable neighborhood-level alert system during events that disrupt cell and internet service. A well-maintained tree can reach 50 households in under 15 minutes using landlines or in-person contact.
Related: social capital, block captain, Map Your Neighborhood
A FEMA-supported program that trains civilians in basic disaster response skills — fire safety, light search and rescue, first aid, and team organization. CERT volunteers serve as a bridge between professional responders and the community during disasters when emergency services are overwhelmed. Training is free and typically involves 20 hours of instruction through local emergency management agencies.
Related: Incident Command System (ICS), Emergency Operations Center (EOC)
The sustained power a generator or battery station can supply, as distinct from the total energy it stores. It limits how much can run at the same moment rather than how long anything runs, and planning above about 80 percent of the rating leaves no headroom. A unit rated 1,000 watts continuous should carry a planned load closer to 800.
Related: Startup Surge, Watt-hour (Wh), Inverter
Printed educational publications produced by state Cooperative Extension Services — typically at land-grant universities — covering agriculture, food preservation, gardening, home economics, and household management. Depression-era Extension bulletins from the 1930s are a primary source for NWS Heritage content, offering tested, practical guidance from a time when household self-reliance was an economic necessity, not a lifestyle choice.
Related: Cooperative Extension, Bureau of Home Economics
A nationwide network of offices — typically one per county — operated by land-grant universities in partnership with the USDA, providing research-based education in agriculture, food safety, home economics, and community development. Extension offices are where Master Gardener programs, food preservation workshops, and 4-H programs are administered. They are an underused civic resource for household self-reliance.
Related: Bureau of Home Economics, Master Gardener, National Center for Home Food Preservation (NCHFP)
The Children's Online Privacy Protection Act, a federal law requiring websites and apps to obtain verifiable parental consent before collecting personal information from children under 13. Most major platforms set their minimum account age at 13 because of COPPA. The FTC updated the rule in April 2025.
Related: Data Broker, Password Manager
A setting at each of the three credit bureaus (Equifax, Experian, TransUnion) that blocks new creditors from pulling your credit report. This prevents anyone from opening accounts in your name, even with your Social Security number. Free by federal law and does not affect your credit score.
Related: Data Broker
The standard unit for stream discharge in the United States, abbreviated cfs. One cubic foot per second equals roughly 449 gallons per minute, a conversion needed whenever a published gauge record is compared against a household measurement. U.S. Geological Survey streamflow data is reported in these units.
Related: Instream Flow, Weir, Hydraulic Head
A mixture of sodium chloride and sodium nitrite, dyed pink to prevent confusion with regular salt, used in meat curing and some sausage-making to inhibit the growth of Clostridium botulinum. Curing salt is measured precisely because both too little and too much carry risk: too little may not prevent botulism, and too much is toxic. It is not a substitute for cooking or proper refrigeration.
Related: Botulism
D
The temperature range between 40°F and 140°F in which foodborne bacteria multiply most rapidly. Perishable food left in the danger zone for more than two hours, or one hour above 90°F, should be discarded. The rule governs everything from outdoor cooking to power-outage food decisions.
Related: food storage
A company that compiles personal information from public records, app data, and online activity into profiles it sells. Data broker profiles can include your name, address history, phone numbers, relatives, and estimated income. You can request removal from most brokers for free.
Related: Credit Freeze, COPPA
The number of days a battery bank can carry its load with no charging input. It is the figure that sizes the bank, because a system built for one cloudy day and one built for four differ mostly in storage cost. Off-grid systems are commonly designed for two to five days depending on climate and how tolerable a shortfall is.
Related: Depth of Discharge (DoD), Lithium Iron Phosphate (LiFePO4), Watt-hour (Wh)
A fast-moving slurry of water, mud, rocks, and vegetation that flows downhill through channels, often triggered by heavy rain on steep slopes burned by wildfire. Debris flows are among the most lethal secondary hazards following wildfire because they move faster than a person can run and can strike with little warning. The 2018 Montecito debris flow in California — triggered by rain over the Thomas Fire burn scar — killed 23 people.
AI-generated or AI-manipulated video, audio, or images designed to look or sound like a real person. Deepfake technology can clone a voice from a few seconds of audio or swap a face onto another person's body in real-time video calls.
Related: Voice Cloning, Phishing
The buffer zone around a home where vegetation and other combustible materials are managed to slow or prevent the spread of wildfire. Defensible space is the single most effective action a homeowner in the WUI can take to protect their home. Most guidelines recommend three zones extending at least 100 feet from the structure.
Related: Wildland-Urban Interface (WUI), Wildfire, fire-adapted community, home hardening
The share of a battery's rated capacity actually drawn down before recharging. Usable capacity is always smaller than nameplate capacity, and discharging deeper shortens the number of cycles a bank will deliver. Lead-acid banks are commonly held near 50 percent, while lithium iron phosphate tolerates 80 to 100 percent depending on the manufacturer.
Related: Lithium Iron Phosphate (LiFePO4), Days of Autonomy, Nameplate Rating
The set of conditions — the strongest wind, the highest flood, the coldest temperature — that an engineered system was built to withstand. When an event exceeds the design basis, the system may fail even if it was built and maintained correctly. Many infrastructure failures occur because the design basis was set decades ago using historical data that no longer reflects current risk.
Related: cascading failure, Levee, building code
A formal determination by the President that a disaster has occurred which exceeds state and local capacity to respond, triggering federal assistance. A disaster declaration unlocks FEMA Individual Assistance for households, Public Assistance for governments, and Hazard Mitigation grants. Not all emergencies receive declarations — the governor must request one and FEMA must assess the damage.
Related: Federal Emergency Management Agency (FEMA), Individual Assistance, SBA disaster loan
Maintaining consistent habits and routines that support long-term preparedness and self-reliance. Discipline is the difference between owning a water filter and actually rotating your stored water on schedule. Most preparedness failures are not failures of equipment but failures of maintenance, practice, and follow-through.
Related: Vigilance, Prudence, Operational Readiness
The final stage of the power grid or water supply that delivers service from a local substation or treatment plant to individual homes and businesses. Distribution infrastructure — the poles, wires, pipes, and valves in your neighborhood — is typically the oldest and most vulnerable part of the system. Most power outages originate in the distribution network, not in generation or transmission.
Related: power grid, water main
An electrical load, usually a resistance heating element, that receives power a household is not using so a generator always has somewhere to send its output. Hydro and wind systems cannot simply be disconnected from their energy source, so surplus must be consumed rather than refused. The load must be able to absorb the machine's full output continuously, since the case it exists for is total loss of household demand.
Related: Runaway Speed, Inverter
A prolonged period of abnormally low precipitation that creates water shortages affecting agriculture, water supply, and fire risk. The U.S. Drought Monitor classifies drought severity from D0 (abnormally dry) to D4 (exceptional drought). Drought is both a hazard itself and a force multiplier for other hazards — it increases wildfire risk, strains water infrastructure, and can trigger agricultural economic crises.
Related: Wildfire
The fraction of time a device actually draws power while it is switched on. Appliances with compressors cycle rather than running continuously, so multiplying watts by hours without it badly overstates energy use. A refrigerator's compressor typically runs about 8 hours out of every 24.
Related: Running Watts, Watt-hour (Wh)
E
A sudden shaking of the ground caused by the release of energy along a geological fault. Earthquakes cannot be predicted with useful precision, making preparedness — structural retrofitting, securing heavy objects, and emergency kits — the primary defense. The San Andreas Fault in California and the New Madrid Seismic Zone in the central U.S. are the two most studied high-risk zones.
Related: seismic retrofit
The independent grid operator that manages the flow of electricity to roughly 90% of Texas. ERCOT is unique among U.S. grid operators because it is largely isolated from the two national interconnections, meaning Texas cannot easily import power from neighboring states during emergencies. This isolation was a central factor in the February 2021 grid collapse during Winter Storm Uri.
Related: power grid, cascading failure, rolling blackout
The national public warning system that broadcasts emergency alerts over radio, television, and cable systems. EAS replaced the older Emergency Broadcast System in 1997 and can be activated at the federal, state, or local level. EAS is the backbone of the national alert infrastructure, though most people now encounter emergency warnings through WEA on their phones.
Related: Wireless Emergency Alert (WEA), NOAA Weather Radio
The physical or virtual location where emergency management personnel coordinate information, resources, and decision-making during a disaster. Counties, cities, and states each maintain EOCs that activate during significant events. EOCs coordinate with FEMA's regional and national operations centers during federally declared disasters.
Related: Incident Command System (ICS), Federal Emergency Management Agency (FEMA), Community Emergency Response Team (CERT)
The rating system used to classify tornado intensity based on the damage they produce, ranging from EF-0 (minor damage, 65–85 mph winds) to EF-5 (total destruction, over 200 mph winds). The scale is applied after an event by survey teams who assess structural damage. Only about 1% of U.S. tornadoes reach EF-4 or EF-5 intensity.
An official directive from local authorities instructing residents to leave a defined area due to an imminent or ongoing threat. Evacuation orders may be mandatory or advisory, depending on jurisdiction and hazard. In most U.S. states, even mandatory evacuation orders cannot legally force residents to leave — but those who stay may not receive emergency assistance.
Related: shelter in place, 72-Hour Bag, Wireless Emergency Alert (WEA)
The practice of physically sealing gaps, cracks, and openings in a building to prevent pests from entering. University extension programs and the EPA identify exclusion as the single most effective component of integrated pest management for homes.
Related: Integrated Pest Management, Harborage
F
A documented plan that ensures every member of a household knows how to reach each other and where to meet if separated during an emergency. The plan should include an out-of-state contact (local lines may be jammed while long-distance calls go through), a meeting place near home, a meeting place outside the neighborhood, and each family member's route from school or work. Write it down — memory fails under stress.
Related: communication tree, 72-Hour Bag, evacuation order
The federal agency responsible for coordinating disaster response, recovery, and preparedness in the United States. FEMA administers Individual Assistance grants, the National Flood Insurance Program, and the public assistance program that reimburses state and local governments after declared disasters. FEMA operates within the Department of Homeland Security.
Related: disaster declaration, Individual Assistance, National Flood Insurance Program (NFIP), SBA disaster loan
A WPA program (1935–1943) that employed writers to produce state guidebooks, oral histories, and cultural documentation across the country. The Project's life-history interviews — roughly 2,900 first-person accounts from farmers, factory workers, sharecroppers, and housewives — are a primary source for understanding how ordinary Americans lived, ate, and managed households during the Depression.
Related: Works Progress Administration (WPA), America Eats, Bureau of Home Economics
The FEMA program that provides financial assistance to individuals and households affected by a federally declared disaster. IA can cover temporary housing, home repairs, and other serious disaster-related needs not covered by insurance. The maximum IA grant changes annually; applicants must register within 60 days of the disaster declaration.
Related: Federal Emergency Management Agency (FEMA), disaster declaration, SBA disaster loan
Practical outdoor and hands-on skills that enable a person to operate effectively in non-ideal conditions. Fieldcraft includes fire-starting, basic navigation, shelter construction, water sourcing, knot-tying, and tool use. These skills are learned through practice, not reading, and they transfer across many preparedness scenarios.
Related: Capability, Resourcefulness, Discipline
An inventory rotation method in which the oldest items are used or consumed first, ensuring nothing expires while newer stock sits in front of it. FIFO is the foundational principle of food storage rotation — place new purchases behind existing stock so the older items get used first. The USDA Bureau of Home Economics taught this system in the 1930s, decades before the acronym existed.
Related: pantry discipline, food storage, shelf life
A conceptual model showing the three factors that determine how a wildfire behaves once ignited: fuel (type, moisture, arrangement), weather (wind, humidity, temperature), and topography (slope, aspect, elevation). Fire behavior is most dangerous when all three factors align — dry fuel, hot windy weather, and uphill terrain. The model is the foundation of wildfire prediction and firefighting strategy.
Related: Wildfire, fuel load, Red Flag Warning
A community in or near the WUI that has taken collective action to reduce its vulnerability to wildfire — including defensible space around homes, fire-resistant building materials, community fuel reduction projects, and practiced evacuation plans. The Firewise USA program, administered by the NFPA, provides a framework for achieving fire-adapted status. The concept shifts responsibility from firefighters alone to the entire community.
Related: defensible space, Wildland-Urban Interface (WUI), Wildfire, building code
A recognition program administered by the National Fire Protection Association that provides a framework for communities in or near the WUI to organize and take action to reduce wildfire risk. Participating communities complete an assessment, develop a plan, invest in annual mitigation projects, and host educational events. Over 2,000 communities in the U.S. currently hold Firewise USA recognition.
Related: fire-adapted community, defensible space, Wildland-Urban Interface (WUI)
The immediate care given to a person who is injured or suddenly ill, before professional medical help arrives. Basic first aid skills — stopping bleeding, treating burns, performing CPR, recognizing stroke and heart attack — are among the most universally useful emergency skills a person can learn. Red Cross and American Heart Association courses provide standardized certification in 4–8 hours.
Related: Community Emergency Response Team (CERT), Red Cross
A device installed inline on a rainwater collection downspout that captures and discards the initial flow of water from a rain event before cleaner water enters the storage barrel. The first flush from a roof carries concentrated bird droppings, atmospheric pollutants, and roofing material residue accumulated during dry periods. Discarding this fraction significantly improves the quality of collected rainwater.
An overflow of water onto land that is normally dry, caused by heavy rain, snowmelt, storm surge, or dam failure. Flooding is the most common and widespread natural hazard in the United States. Flash floods — rapid flooding within six hours of heavy rain — cause the majority of flood-related deaths.
Related: National Flood Insurance Program (NFIP), Floodplain, storm surge
The flat area adjacent to a river or coast that is naturally subject to periodic flooding. FEMA maps floodplains to determine insurance requirements and building restrictions. The commonly used term '100-year flood' means a flood that has a 1% chance of occurring in any given year — not that it happens only once per century.
Related: Flood, National Flood Insurance Program (NFIP)
The practice of maintaining a supply of shelf-stable food in the home for use during disruptions — power outages, supply chain interruptions, weather events, or income loss. A practical household food store starts with 72 hours of no-cook food and builds toward a 14-day rotating pantry of foods the household already eats. The key principle is rotation — stored food should be consumed and replaced regularly, not packed away and forgotten.
Related: FIFO (First In, First Out), pantry discipline
A small tank between an intake and a penstock where water slows enough for sand and sediment to settle out before reaching the turbine. It also keeps air out of the pipe when the water level changes suddenly, and provides a place that can be drawn down and cleaned.
Related: Penstock, Trash Rack, Tailrace
The practice of anticipating future needs, risks, and conditions before they arrive. Foresight is the foundation of all preparedness: storing water before the outage, reviewing insurance before the storm, building savings before the job loss. It is not prediction; it is the habit of asking what could change and preparing accordingly.
Related: Prudence, Situational Awareness, Readiness
Strength of character and resolve when facing adversity, discomfort, or prolonged difficulty. Fortitude is what sustains a household through a week-long power outage, a months-long recovery, or the steady work of building self-reliance over years. It is built through small, repeated choices to do the harder, more useful thing.
Related: Resilience, Stoicism, Discipline
The maximum depth to which the ground freezes in a given climate. Water pipes, well casings, and underground supply lines must be buried below the frost line to avoid freeze damage. Frost line depth ranges from near zero in the Deep South to 6 feet or more in northern states.
Related: Rain Barrel
The total amount of combustible material — dead leaves, fallen branches, standing dead trees, dense undergrowth — present in a given area of wildland. High fuel loads mean more material for a fire to consume, producing more intense heat and faster spread. A century of fire suppression in U.S. forests has allowed fuel loads to build far beyond historical levels in many ecosystems.
Related: Wildfire, prescribed burn, fire behavior triangle
G
A mechanical device installed on a home's electrical panel that prevents a portable generator from back-feeding power into the utility grid — which can electrocute lineworkers. An interlock or transfer switch is required by the National Electrical Code for any generator connected to a home's wiring. Running a generator without one is both illegal and potentially fatal to utility workers restoring power.
Related: power grid, portable generator
A water filtration device that moves water through filter elements using gravity alone, requiring no electricity, pumps, or plumbing connection. Water poured into an upper chamber drips slowly through the filter media into a lower chamber ready to drink. Most household gravity filters use carbon block or ceramic elements and sit on a countertop.
Related: Reverse Osmosis, Hollow Fiber Membrane, NSF/ANSI Certification, PFAS (Per- and Polyfluoroalkyl Substances)
H
Any location that provides shelter, cover, or nesting opportunity for pests. Common residential harborage includes dense vegetation against foundations, woodpiles near the house, cluttered storage areas, and undisturbed spaces under decks or in crawlspaces. Reducing harborage is a core principle of integrated pest management.
Related: Exclusion, Integrated Pest Management
Strengthening a system, structure, or process against failure. A home can be hardened against storms with impact-resistant shutters; a financial position can be hardened with emergency savings; a communication plan can be hardened with backup channels. Hardening is preventive work done before conditions deteriorate.
Related: Resilience, Readiness, Operational Readiness
A three-level federal system rating a dam as low, significant or high hazard potential according to the probable loss of life, economic loss and environmental damage that would follow a failure. It describes consequences rather than the condition of the structure, so a well-built dam above an occupied valley is high hazard. A classification can change without the dam changing, if development appears downstream.
Related: Spillway, Impoundment
A USDA nutritionist who developed the four-tier dietary framework (liberal, moderate, minimum, restricted) that became the basis for federal food assistance policy. Her 1936 bulletin 'Diets to Fit the Family Income' demonstrated that a family could eat nutritiously at minimal cost — a framework that directly influenced what became the USDA Thrifty Food Plan, the basis for modern SNAP benefits.
Related: Bureau of Home Economics, Thrifty Food Plan, Supplemental Nutrition Assistance Program (SNAP)
A rigid, food-safe plastic identified by recycling symbol number 2, used in purpose-built water storage containers, food storage bins, and cutting boards. HDPE does not leach harmful chemicals into water under normal storage conditions and is rated for long-term food and water contact by the FDA. It is the standard material for emergency water storage containers.
Related: Potable
An electrical heating element designed to wrap around pipes, valves, or other components to prevent freezing. Heat tape draws power continuously or thermostatically, making it effective but dependent on electricity. Also called heat cable.
Related: Frost Line
A prolonged period of abnormally high temperatures that poses health risks, strains power grids, and can be fatal — especially for elderly people, outdoor workers, and those without air conditioning. Heat is the deadliest weather hazard in the United States in most years, killing more people than hurricanes, tornadoes, and floods combined. The definition varies by region — 95°F in Seattle is more dangerous than 95°F in Phoenix because the population and infrastructure are not adapted to it.
Related: power grid, rolling blackout, Drought
A filtration technology using thousands of tiny tubes with microscopic pores that physically block bacteria, protozoa, and sediment while allowing water molecules to pass through. Hollow fiber filters are the core technology in portable filters like the Sawyer Squeeze and LifeStraw. They can be restored to near-original flow rate by backflushing water through the filter in reverse.
Related: Micron, Backflush, Gravity Filter
The process of modifying a home's exterior to resist ignition from wildfire embers, radiant heat, and direct flame contact. Key measures include replacing wood shake roofs with Class A rated materials, installing metal mesh over vents, using tempered or multi-pane windows, and removing combustible materials from within five feet of the structure. Research shows that home hardening and defensible space together are more effective than either alone.
Related: defensible space, Wildland-Urban Interface (WUI), building code, fire-adapted community
A large rotating storm system that forms over warm ocean water, with sustained winds of 74 mph or higher. Hurricanes bring a combination of wind, storm surge, inland flooding, and tornadoes that can devastate coastlines and penetrate hundreds of miles inland. The Atlantic hurricane season runs from June 1 through November 30.
Related: storm surge, Saffir-Simpson scale, evacuation order, National Oceanic and Atmospheric Administration (NOAA)
The vertical distance water falls between an intake and the machine it drives, and the figure that with flow rate determines how much power a site can produce. Gross head is the true drop measured with the water standing still. Net head is what remains after pipe friction takes its share, and it is the number that actually makes power. One pound per square inch of pressure corresponds to 2.31 feet of head.
Related: Cubic Feet per Second, Penstock, Micro-Hydro, Weir
I
A body of water held behind a dam or embankment. Impounding water converts a stream's continuous output into power available on demand and can create head on flat ground, at the cost of engineering, permitting and permanent legal liability that a diversion does not carry. FEMA states that dam owners can be fiscally and criminally liable for any failure and the damages that follow.
Related: Spillway, Hazard Potential Classification, Run-of-River
A water turbine driven by the velocity of a jet striking its runner in open air, rather than by pressure across submerged blades. The runner is not immersed and the casing carries no pressure, which makes these the simplest machines to build and inspect. Pelton, Turgo and cross-flow turbines are impulse designs, and they suit high-head sites with modest flow.
Related: Reaction Turbine, Runaway Speed, Hydraulic Head
The standardized management structure used to organize emergency response in the United States. ICS provides a common framework — Incident Commander, Operations, Planning, Logistics, Finance — that allows multiple agencies to work together during any type of incident. Every FEMA-coordinated response and most local emergency responses use ICS.
Related: Emergency Operations Center (EOC), Community Emergency Response Team (CERT), Federal Emergency Management Agency (FEMA)
Freedom from dependence on systems, services, or other people for essential needs. Independence in preparedness is practical, not ideological. It means a household can provide its own water, power, heat, food, and communication for a meaningful period when normal supply is interrupted. Full independence is rare; meaningful independence is achievable.
Related: Autonomy, Self-Sufficiency, Resilience
The quantity of water that must remain in a stream channel rather than being diverted, set by state regulators to protect fish, aquatic habitat and downstream users. For anyone planning a diversion it is the figure that matters most, because the permitted design flow is what remains after the instream requirement is met rather than what the stream carries.
Related: Riparian Rights, Prior Appropriation, Cubic Feet per Second
A professional who inspects property damage after a disaster and determines how much the insurance company will pay on a claim. Adjusters may work for the insurance company (staff adjuster), for the policyholder (public adjuster), or independently. Policyholders have the right to hire a public adjuster to represent their interests, typically for 5–15% of the claim settlement.
Related: National Flood Insurance Program (NFIP)
A prevention-first approach to pest control that prioritizes exclusion, sanitation, and habitat modification before considering chemical treatments. IPM programs use information about pest biology to choose the safest, most effective methods. The EPA describes it as an environmentally sensitive, common-sense approach.
Related: Exclusion, Harborage, Vector
A device that converts direct current from a battery or solar panel into the alternating current household appliances use. Inverter quality determines what can safely be run, since sensitive electronics and variable-speed motors need a clean waveform. Conversion is not free, and roughly 10 to 15 percent of stored energy is lost as heat.
Related: Continuous Output, Watt-hour (Wh), Solar Panel
J
A supply chain strategy in which goods are delivered to stores and warehouses only as they are needed, minimizing storage costs but reducing the buffer against disruption. Most U.S. grocery stores operate on a 3-day just-in-time cycle, meaning the store's shelves represent roughly three days of normal demand. Any disruption to transportation, distribution, or demand patterns can empty shelves within days.
Related: cold chain
L
The downslope movement of rock, soil, or debris driven by gravity, often triggered by heavy rainfall, earthquakes, or wildfire that destroys stabilizing vegetation. Post-wildfire landscapes are especially vulnerable to debris flows because the burned soil repels water instead of absorbing it. Landslides cause an average of 25–50 deaths per year in the U.S. and billions in property damage.
Related: Wildfire, Earthquake, Flood
An embankment — earthen or concrete — built along a waterway to contain floodwater and protect adjacent land. Levees are designed to a specific capacity; when a flood exceeds that design basis, the levee can be overtopped or may fail structurally. The U.S. has roughly 30,000 miles of levees, and the Army Corps of Engineers rates many as deficient.
Related: Floodplain, Flood, design basis
A bacterium that can grow even in refrigerated conditions, unlike most foodborne pathogens, making it a particular concern in soft cheeses, deli meats, and unpasteurized dairy. Listeriosis, the illness it causes, is especially dangerous for pregnant women, older adults, and people with weakened immune systems. Careful pasteurization and proper aging are the main defenses in home food preparation.
A lithium battery chemistry used widely in solar storage and portable power stations. It tolerates deeper discharge and delivers far more cycles than lead-acid, at a higher cost per unit of capacity. Most LiFePO4 batteries must not be charged below freezing unless they carry an internal heater, though they can usually be discharged well below it.
Related: Depth of Discharge (DoD), Days of Autonomy
The current a motor draws at the instant it starts, before the rotor begins to turn. Some appliance nameplates print it, and where they do it is the authoritative figure for startup demand rather than any general multiplier. It is a worst case, so real starting draw is usually briefer and lower.
Related: Startup Surge, Nameplate Rating
M
A community preparedness program that organizes neighbors into small groups (typically 15–20 households) to identify skills, resources, and vulnerabilities on their block before a disaster occurs. MYN was developed by the Washington State Emergency Management Division and has been adopted by communities across the country. The program takes about two hours to complete and produces a resource map, contact list, and simple action plan.
Related: communication tree, social capital, block captain, Community Emergency Response Team (CERT)
A trained volunteer who completes 40–100 hours of horticultural education through a state's Cooperative Extension Service and then provides gardening advice and community education in return. Master Gardener programs exist in all 50 states and are free or low-cost to participants. They are one of the most accessible civic on-ramps for learning food production skills.
Related: Cooperative Extension
A charge controller design that continuously adjusts the load it places on a solar array so the panels operate at their most productive combination of voltage and current. It lets a high-voltage array charge a lower-voltage battery bank without wasting the difference. MPPT controllers typically recover more energy than PWM controllers, with the largest gains in cold weather and low light.
Related: Pulse Width Modulation (PWM), Open-Circuit Voltage (Voc), Solar Panel
Small-scale hydroelectric generation, defined by the Department of Energy as systems producing up to 100 kilowatts. Most household installations fall far below that. Its distinguishing advantage over solar and wind is that it generates continuously, so a modest output multiplied by every hour of the year can exceed a much larger intermittent system.
Related: Run-of-River, Hydraulic Head, Penstock
A unit of measurement equal to one millionth of a meter, used to describe the pore size of water filters. A filter's micron rating indicates the smallest particle it will physically block: a 0.1-micron filter blocks bacteria and protozoa, while a 0.2-micron filter blocks protozoa but may allow some bacteria through. Viruses, at 0.02 to 0.3 microns, pass through most hollow fiber filters.
Related: Hollow Fiber Membrane, Gravity Filter, Reverse Osmosis
The process of identifying, containing, and removing mold growth from a building after water damage. Mold can begin growing within 24–48 hours of water intrusion and poses respiratory health risks, especially for children, elderly people, and those with asthma. Professional remediation is recommended when mold covers more than 10 square feet or is found inside wall cavities or HVAC systems.
Related: structural assessment
A practice of reciprocal support in which community members voluntarily share resources, skills, and labor based on need rather than charity. Mutual aid networks are peer-to-peer — participants both give and receive — distinguishing them from top-down charitable organizations. Historical examples include Depression-era cooperative buying clubs, community canning centers, and church dinner rotations.
Related: social capital, communication tree
N
The maximum power draw printed on an appliance label, measured with every feature operating at once. It is a wiring and safety figure rather than a consumption figure, so sizing from it leads to buying far more capacity than needed. For motor-driven appliances it can be three to four times the running draw.
Related: Running Watts, Locked-Rotor Amps (LRA)
The USDA-funded research center at the University of Georgia that develops and maintains the current science-based guidelines for safe home food preservation. NCHFP recommendations are the definitive authority on canning times, pressures, and methods in the United States. Any historical preservation recipe should be cross-checked against NCHFP guidelines before use.
Related: pressure canner, water-bath canning
The federal program that provides flood insurance to property owners, renters, and businesses in participating communities. Standard homeowner's insurance does not cover flood damage — NFIP policies are typically the only source of flood coverage for most households. NFIP policies have a 30-day waiting period before coverage takes effect.
Related: Flood, Floodplain, Federal Emergency Management Agency (FEMA)
The federal science agency responsible for monitoring oceans, atmosphere, and climate, and for providing weather and climate data. NOAA is the parent agency of the National Weather Service, the National Hurricane Center, and the Storm Prediction Center. NOAA satellites provide the imagery and data that power most weather forecasting in the United States.
Related: National Weather Service (NWS), NOAA Weather Radio
The federal agency within NOAA responsible for weather forecasting, severe weather warnings, and climate monitoring in the United States. The NWS operates 122 local forecast offices that issue watches, warnings, and advisories for their respective regions. NWS forecasters are the source of tornado warnings, hurricane forecasts, flood watches, Red Flag Warnings, and winter storm alerts.
Related: National Oceanic and Atmospheric Administration (NOAA), NOAA Weather Radio, Red Flag Warning, SKYWARN
A nationwide network of radio stations that broadcast continuous weather information directly from National Weather Service offices. Weather radios can be programmed to sound an alarm for specific hazards in your county — severe thunderstorms, tornadoes, flash floods, and other warnings. It is the only alert system that works without internet or cell service.
Related: Wireless Emergency Alert (WEA), Red Flag Warning, National Weather Service (NWS)
An independent product certification issued by NSF International verifying that a water treatment device meets specific performance standards. Each standard number covers different contaminants: NSF 42 covers taste and odor, NSF 53 covers health contaminants including PFAS when specifically listed, and NSF 58 covers reverse osmosis systems. A product certified to one standard is not automatically certified to others.
Related: PFAS (Per- and Polyfluoroalkyl Substances), Gravity Filter, Reverse Osmosis
O
The voltage a solar panel or string produces when nothing is connected to draw current. It is the highest voltage the array will ever present, and it rises as temperature falls, which is what limits how many panels can be wired in series. String length is calculated against the record low temperature for the site rather than an average.
Related: Maximum Power Point Tracking (MPPT), Solar Panel, Voltage Drop
Being fully capable of acting immediately when conditions require it. Operational readiness means supplies are accessible, equipment is tested and maintained, plans are current, and household members know their roles. It is the difference between having a plan and being ready to execute it right now.
Related: Readiness, Discipline, Capability
A waterwheel fed from above, where water enters buckets at the top and turns the wheel by its weight as it descends. The most efficient of the traditional wheel arrangements, reaching around 85 percent in measured tests, and the one needing the most drop. Wheel diameter is set by available head, which is why overshot wheels are generally used where the fall is no more than about six meters.
Related: Waterwheel, Hydraulic Head
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The systematic practice of maintaining, rotating, and inventorying a household food supply so that nothing expires unused and staples are always available. Pantry discipline includes FIFO rotation, regular inventory checks, purchasing based on what's actually used (not aspirational), and seasonal restocking. The USDA Bureau of Home Economics taught these systems in the 1930s as basic household economics.
Related: FIFO (First In, First Out), food storage, shelf life
A serious, sometimes fatal illness caused by eating shellfish that have accumulated toxins produced by certain algae blooms, commonly called red tide. PSP toxins are not destroyed by cooking, which is why shellfish harvesting depends on checking official closure status before every outing rather than on any preparation method. Symptoms can begin within minutes and progress to respiratory paralysis in severe cases.
Related: Danger Zone (Food Safety)
A login method that replaces your password with your device's own unlock, such as a fingerprint or face scan. Passkeys cannot be phished because there is no password to steal. They are supported by most major platforms and are recommended by CISA as phishing-resistant authentication.
Related: Two-Step Verification, Password Manager, Phishing
A program that generates, stores, and fills in a unique password for every account you use. You remember one master password or use your device's biometric unlock; the manager handles the rest. Most cost between zero and five dollars per month.
Related: Passkey, Two-Step Verification, Recovery Code
The number of hours per day that sunlight would need to fall at the standard test intensity of 1,000 watts per square metre to deliver the same total energy a site actually receives. It converts a location's sunlight into one figure that can be multiplied by array size to estimate output. Nine hours of winter daylight is not nine peak sun hours, and treating it that way overstates winter production several times over.
Related: Solar Panel, Watt-hour (Wh)
The pressure pipe carrying water from an intake down to a turbine. Its diameter governs how much of a site's head survives the trip, because friction rises steeply as bore falls, and it is usually the largest single cost in a micro-hydro project. Common practice is to size it so friction costs no more than 10 to 15 percent of gross head.
Related: Hydraulic Head, Forebay, Water Hammer, Run-of-River
Polyethylene terephthalate, the thin, clear plastic used in commercially bottled water and soft drink bottles. PET is lighter and less durable than HDPE and degrades faster under heat and UV exposure. Research has shown that sustained high temperatures can promote leaching of antimony from PET containers.
Related: HDPE (High-Density Polyethylene), Shelf Life
A group of more than 12,000 synthetic chemical compounds used in industrial processes and consumer products since the 1940s. PFAS do not break down naturally in the environment or the human body, earning the name 'forever chemicals.' Exposure through drinking water has been linked to thyroid disruption, immune system effects, and elevated risk of certain cancers.
Related: NSF/ANSI Certification, Reverse Osmosis, Gravity Filter
A measurement of acidity or alkalinity on a scale of 0 to 14, with lower numbers indicating higher acidity. In home food preservation, pH determines which canning method is safe: foods at pH 4.6 or below can be safely water-bath canned, while foods above that threshold require pressure canning to destroy botulism spores. Testing pH matters most when a recipe adds acid to a naturally low-acid food.
Related: water-bath canning, pressure canner, Botulism
A scam in which an attacker sends a message, usually by email or text, designed to trick you into clicking a link, entering your password, or providing personal information. Phishing messages often impersonate banks, government agencies, or companies you use.
Related: Two-Step Verification, Passkey, Deepfake
A fuel-powered engine that produces electricity for temporary use during a power outage. Portable generators can power essential appliances — refrigerators, medical devices, lights, phone chargers — but must be operated outdoors due to carbon monoxide risk. Carbon monoxide from generators kills more people after hurricanes than the storms themselves in many events.
Related: generator interlock, power grid, carbon monoxide
The practice of confirming a wild plant, mushroom, or other foraged food matches a single edible species with total certainty, using multiple physical characteristics rather than a partial resemblance. Positive identification is the foundational discipline of foraging, because look-alike species can be mildly unpleasant or fatally toxic. The rule among experienced foragers is simple: never eat on a maybe.
Safe for human consumption — meaning the water has been treated, tested, or verified to be free of harmful biological and chemical contaminants at levels exceeding health standards. Tap water from a public water system is potable; untreated surface water from a stream or rain barrel is not.
Related: boil water advisory, Gravity Filter, Reverse Osmosis
Water that is safe to drink, cook with, and use for personal hygiene without risk of illness. Municipal tap water in the U.S. is treated to potable standards, but that treatment depends on functioning infrastructure — power to run treatment plants, intact distribution pipes, and chemical supply chains. When any of those fail, tap water may no longer be potable, and a boil water advisory or do-not-use order is issued.
Related: boil water advisory, water storage
The interconnected network of generation plants, transmission lines, and distribution systems that delivers electricity from producers to consumers. The U.S. grid operates as three major interconnections — Eastern, Western, and ERCOT (Texas) — that function largely independently. The grid is the single most complex machine in the country, with roughly 160,000 miles of high-voltage transmission lines.
Related: cascading failure, Electric Reliability Council of Texas (ERCOT), rolling blackout, generator interlock
A planned, intentionally set fire used to manage vegetation, reduce fuel loads, and restore fire-dependent ecosystems. Prescribed burns are conducted under specific weather conditions by trained crews with containment resources in place. Decades of fire suppression have created a prescribed burn deficit — the backlog of land that needs burning far exceeds current capacity.
Related: Wildfire, defensible space, fuel load
A specialized piece of kitchen equipment that processes food in sealed jars at temperatures above 240°F — the temperature required to destroy Clostridium botulinum spores in low-acid foods like vegetables, meat, and poultry. A pressure canner is not the same as a pressure cooker; canners are larger, have a pressure gauge or weighted regulator, and are tested to specific standards. Pressure canning is the only safe method for home preservation of low-acid foods.
Related: National Center for Home Food Preservation (NCHFP), water-bath canning
The water law tradition followed in most western states, under which rights are allocated by seniority of first beneficial use rather than by land ownership. First in time, first in right: a senior holder downstream is entitled to their full allocation before a junior holder upstream may take any. Rights are tied to beneficial use and can be lost through non-use.
Related: Riparian Rights, Instream Flow
Making careful, forward-thinking decisions that account for future consequences. Prudent preparedness means building capability steadily rather than panic-buying, choosing reliable equipment over the cheapest option, and maintaining what you have before acquiring more.
Related: Foresight, Discipline, Sustainability
A simpler charge controller design that connects the solar array almost directly to the battery and regulates charging by switching that connection on and off rapidly. The array is pulled down to battery voltage, so panel voltage above that is lost rather than converted. PWM controllers cost less and suit small systems where panel and bank voltages already match closely.
Related: Maximum Power Point Tracking (MPPT), Solar Panel
R
A container that captures and stores rainwater from a roof's gutter system for later use in irrigation, cleaning, or emergency water supply. Rain barrels are legal in most U.S. states, though some states regulate the volume that can be collected. A single barrel typically holds 50–80 gallons; the water is not potable without treatment.
Related: water storage
A water turbine that runs full of water, with every blade in contact with it, taking power from the pressure drop across the runner rather than from a jet. Propeller, Kaplan and Francis machines belong to this family, along with pumps run backward. They suit lower head with higher flow and generally deliver more power from a smaller machine than an impulse design.
Related: Impulse Turbine, Hydraulic Head
The state of being equipped, informed, and mentally prepared to respond to challenges or emergencies. In a preparedness context, readiness means having plans, supplies, skills, and the calm confidence to act when conditions change.
Related: Resilience, Operational Readiness, Capability
A one-time-use code provided when you enable two-step verification. Recovery codes let you regain access to your account if you lose your phone or authenticator app. Store them in a printed list or your household account inventory, not on the device they protect.
Related: Two-Step Verification, Password Manager
A forecast alert issued by the National Weather Service when weather conditions are especially favorable for wildfire ignition and rapid spread — typically a combination of low humidity, high temperatures, and strong winds. Red Flag Warnings trigger increased staffing at fire stations and pre-positioning of suppression resources. They do not mean a fire has started — they mean conditions are dangerous if one does.
Related: Wildfire, National Weather Service (NWS), NOAA Weather Radio
The capacity to withstand disruption and recover from hardship without permanent loss of function. Resilience applies at every scale, from a single household maintaining normalcy during a power outage to a community rebuilding after a flood. Physical preparedness, financial reserves, social networks, and mental fitness all contribute to resilience.
Related: Readiness, Fortitude, Sustainability
The ability to solve problems with whatever is available rather than waiting for ideal conditions or supplies. Resourcefulness is a skill that improves with practice. Heritage-era households, working with far fewer commercial products, developed resourcefulness as a core survival trait.
Related: Capability, Fieldcraft, Resilience
A water filtration method that forces water under pressure through a semi-permeable membrane with pores small enough to block dissolved contaminants, including PFAS, arsenic, nitrates, fluoride, and lead. Reverse osmosis systems are certified to NSF/ANSI 58 and remove a broader range of chemical contaminants than carbon or gravity filters. They require electricity and produce waste water alongside purified water.
Related: PFAS (Per- and Polyfluoroalkyl Substances), NSF/ANSI Certification, Gravity Filter, Micron
The water law tradition followed in most eastern states, under which landowners along a watercourse hold a right to make reasonable use of the water so long as that use does not unreasonably harm other owners along the same water. The right attaches to the land and is not lost through non-use. Most eastern states now administer it through a permit system rather than leaving it to common law alone.
Related: Prior Appropriation, Instream Flow, Hydraulic Head
An intentional, temporary shutdown of electricity to rotating sections of the grid to prevent a total system collapse when demand exceeds supply. Rolling blackouts typically last 15–60 minutes per area before power is restored and the blackout moves to the next zone. They are a last-resort measure that signals the grid is at or beyond its limits.
Related: power grid, Electric Reliability Council of Texas (ERCOT), cascading failure
A hydroelectric arrangement that diverts part of a stream through a pipe to a turbine and returns it to the same stream a short distance downstream, without building a reservoir or flooding land. Most micro-hydro systems work this way and use only a fraction of available flow. The trade is that output follows the stream rather than household demand, since nothing is stored.
Related: Micro-Hydro, Penstock, Tailrace, Impoundment
The speed a turbine reaches when its electrical load disappears and nothing absorbs the energy still arriving. For an impulse water turbine it is roughly 1.8 times rated speed, reached within seconds, and it is treated as the worst-case mechanical load a machine will see. Because centrifugal stress rises with the square of speed, the forces on the rotating parts more than triple.
Related: Diversion Load, Water Hammer, Impulse Turbine
The power a device draws during normal operation, as opposed to its maximum or startup draw. This is the figure that matters for sizing backup power, and it is usually far below the number printed on the appliance. A refrigerator labelled 725 watts commonly runs at 100 to 200.
Related: Nameplate Rating, Startup Surge, Duty Cycle
S
The 1–5 rating system used to classify hurricane intensity based on sustained wind speed, from Category 1 (74–95 mph, minimal damage) to Category 5 (157+ mph, catastrophic damage). The scale measures only wind — it does not account for storm surge, rainfall, or flooding, which often cause more damage and deaths than wind alone. A Category 1 hurricane with heavy rain can cause more flooding damage than a Category 4 with less rain.
Related: Hurricane, storm surge
A low-interest loan from the U.S. Small Business Administration available to homeowners, renters, businesses, and nonprofits after a declared disaster. Despite the name, SBA disaster loans are available to individuals, not just businesses — they cover property damage, personal property replacement, and economic injury. Loan amounts can reach $500,000 for real estate and $100,000 for personal property.
Related: Federal Emergency Management Agency (FEMA), disaster declaration, Individual Assistance
The modification of an existing building to make it more resistant to earthquake damage — typically by bolting the structure to its foundation, bracing cripple walls, and reinforcing connections between floors and walls. In earthquake-prone regions, seismic retrofits are among the most cost-effective preparedness investments a homeowner can make. Some jurisdictions offer incentive programs that cover a portion of retrofit costs.
Related: Earthquake, building code, structural assessment
The ability to meet your own essential needs without relying on outside support. Self-sufficiency exists on a spectrum, from maintaining a three-day water supply to growing a significant portion of your own food. Most households benefit from building toward greater self-sufficiency incrementally rather than attempting full independence overnight.
Related: Autonomy, Independence, Sustainability
The length of time a food product remains safe and nutritionally adequate when stored under recommended conditions. 'Best by' and 'use by' dates on most shelf-stable foods are quality indicators, not safety cutoffs — many products remain safe well past those dates. The exception is infant formula, which has a federally regulated use-by date tied to nutrient degradation.
Related: FIFO (First In, First Out), food storage, pantry discipline
An emergency instruction to remain inside your current building and seal it against an external hazard — typically a chemical release, severe weather, or active threat. Sheltering in place is distinct from evacuation; it means staying put, closing windows and doors, and in chemical events, sealing gaps with plastic and tape. The decision to shelter vs. evacuate depends on the specific hazard.
Related: evacuation order, 72-Hour Bag, NOAA Weather Radio
Understanding your environment, recognizing what is normal, and noticing when conditions change. In preparedness, situational awareness means knowing the hazards in your region, understanding the systems your household depends on, and maintaining enough attention to recognize when something shifts. It is a trainable skill, not an innate trait.
Related: Vigilance, Foresight, Operational Readiness
A National Weather Service program that trains volunteer weather spotters to identify and report severe weather conditions — tornadoes, large hail, damaging winds, and flash flooding — to their local NWS forecast office. SKYWARN training is free, typically 2–3 hours, and available through local NWS offices. Spotter reports are a critical data source for NWS forecasters issuing warnings.
Related: National Weather Service (NWS), NOAA Weather Radio, Community Emergency Response Team (CERT)
A device that converts sunlight into electricity using photovoltaic cells. For household preparedness, solar panels paired with battery storage provide backup power that does not depend on fuel or the grid. A basic portable solar setup (200W panel + battery station) can keep phones charged, run LED lights, and power a small refrigerator during a multi-day outage.
Related: generator interlock, power grid
The controlled route by which a dam passes water it cannot hold. Its capacity is sized against an inflow design flood rather than against ordinary experience, and inadequate capacity is among the leading causes of dam failure. A spillway partly blocked by debris is a smaller spillway, and the blockage tends to arrive with the storm that needs full capacity.
Related: Impoundment, Hazard Potential Classification
The standard residential electrical supply in North America, delivering both 120 volts and 240 volts from the same service. Large appliances such as ranges, dryers, and well pumps use the 240-volt side, which portable power stations cannot produce at any capacity. This is why a 240-volt device cannot run from a battery station regardless of size.
Related: Generator Interlock, Continuous Output
The brief spike in power a motor or compressor draws in the moment it starts. Surge is a pass-or-fail limit rather than something a safety margin absorbs, so a station can hold ample energy and still fail to start a refrigerator. Sealed compressors commonly draw three to five times running watts for a second or two.
Related: Locked-Rotor Amps (LRA), Running Watts, Continuous Output
A philosophical tradition emphasizing emotional self-regulation, focus on what you can control, and endurance through difficulty. In a preparedness context, stoic principles apply directly: control your response rather than the situation, prepare for what is likely rather than fear what is possible, and maintain composure so those around you can function.
Related: Fortitude, Discipline, Agency
An abnormal rise in sea level generated by a storm's winds pushing ocean water onshore. Storm surge is the deadliest hazard associated with hurricanes, responsible for more fatalities than wind in most major events. Surge heights can exceed 20 feet in extreme storms.
Related: Hurricane, evacuation order, Flood
A professional evaluation of a building's structural integrity after a disaster — determining whether the structure is safe to enter, safe to occupy, or requires demolition. Structural assessments should be performed by a licensed structural engineer, not a general contractor. A typical post-disaster residential assessment costs $300–$600.
Related: mold remediation, building code
The federal agency within HHS that leads public behavioral health efforts, including disaster mental health response. SAMHSA operates the Disaster Distress Helpline (1-800-985-5990) — a 24/7 crisis counseling service for people experiencing emotional distress related to any natural or human-caused disaster. The helpline is free, multilingual, and confidential.
A severe thunderstorm characterized by a deep, persistent rotating updraft called a mesocyclone. Supercells are the most dangerous type of thunderstorm and are responsible for nearly all significant tornadoes, as well as very large hail, damaging winds, and flash flooding. They can persist for hours and travel hundreds of miles.
The federal program that provides nutrition assistance to low-income individuals and families through an electronic benefits transfer (EBT) card usable at authorized retailers. SNAP benefits are calculated based on the USDA Thrifty Food Plan — the minimum-cost nutritionally adequate diet. After a presidential disaster declaration, D-SNAP (Disaster SNAP) can provide temporary food benefits to disaster-affected households that don't normally qualify.
Related: Thrifty Food Plan, Hazel Stiebeling, Federal Emergency Management Agency (FEMA)
Maintaining long-term viability with limited or finite resources. In preparedness, sustainability means building systems that can function over weeks and months, not just the first 72 hours. A garden that produces food year after year is more sustainable than a stockpile that depletes. Sustainable preparedness plans account for resupply, rotation, and maintenance.
Related: Self-Sufficiency, Resilience, Prudence
T
The channel returning water to a stream after it has passed through a turbine. Its outlet needs protection from erosion, because water leaving a machine still carries energy, and in cold climates an iced tailrace can back water up into the powerhouse.
Related: Run-of-River, Penstock, Forebay
A measure of the combined concentration of all inorganic and organic substances dissolved in water, expressed in milligrams per liter or parts per million. TDS includes minerals like calcium and magnesium (which are harmless or beneficial), as well as contaminants like nitrates and heavy metals. A high TDS reading does not indicate unsafe water; a low reading does not confirm safety.
Related: Reverse Osmosis, Turbidity
The USDA's estimate of the minimum cost of a nutritionally adequate diet, used as the basis for calculating SNAP (food stamp) benefits. The Thrifty Food Plan is a direct descendant of Hazel Stiebeling's 1936 four-tier dietary framework. It is updated periodically — the most recent revision in 2021 increased the estimated cost by roughly 20%.
Related: Hazel Stiebeling, Supplemental Nutrition Assistance Program (SNAP), Bureau of Home Economics
A violently rotating column of air extending from a thunderstorm to the ground. Tornadoes can produce winds exceeding 300 mph and destroy well-built structures in seconds. The U.S. experiences roughly 1,200 tornadoes per year, more than any other country.
A coarse screen at a water intake that stops branches, leaves and gravel from entering the system. It handles large debris, leaving finer material to a screen further along. Any screen fine enough to stop pine needles is fine enough to clog with them, which makes cleaning access a design question rather than an afterthought.
Related: Coanda Screen, Forebay, Weir
A series of ocean waves generated by a large-scale disturbance — usually an undersea earthquake, volcanic eruption, or submarine landslide. Tsunami waves can travel across entire ocean basins at jet speed and arrive at coastlines with devastating force. The Pacific Northwest and Alaska are the U.S. regions with the highest tsunami risk, though the Atlantic and Gulf coasts have historical exposure.
Related: Earthquake, evacuation order
A measure of water cloudiness caused by suspended particles — sediment, algae, or other matter that scatters light passing through the water. High turbidity can interfere with chemical disinfection by shielding pathogens from UV light or chlorine contact. Turbid water should be pre-filtered or allowed to settle before chemical treatment.
Related: Potable, Hollow Fiber Membrane, Backflush
A security method that requires two separate forms of proof to log in, typically your password plus a code from your phone or an authenticator app. If an attacker obtains your password, they still cannot access your account without the second factor.
Related: Passkey, Password Manager, Phishing
U
The federal science agency responsible for studying the nation's landscape, natural resources, and natural hazards — including earthquakes, volcanoes, landslides, and wildfire. USGS operates the earthquake monitoring network, produces wildfire risk maps, and maintains stream gauges that feed flood forecasting models. USGS data is the foundation of most natural hazard risk assessments in the United States.
Related: Earthquake, Wildfire, National Oceanic and Atmospheric Administration (NOAA)
V
An organism that transmits a pathogen from one host to another. In household pest management, common vectors include mosquitoes (which can carry West Nile virus and other diseases) and ticks (which can carry Lyme disease and other tick-borne illnesses). Rodents can also serve as vectors for hantavirus and other pathogens.
Related: Integrated Pest Management
Sustained, calm attention to conditions that could affect household safety or stability. Vigilance is not anxiety. It is the practiced habit of monitoring weather alerts, checking supplies on a schedule, maintaining equipment, and staying informed through reliable sources without letting the monitoring itself become a source of stress.
Related: Situational Awareness, Foresight, Discipline
The use of AI to replicate a specific person's voice from a short sample of their speech. Cloned voices are used in scams where the caller impersonates a family member, bank representative, or government official. A family code word and the callback habit are the primary household defenses.
Related: Deepfake
The loss of voltage along a conductor caused by its own resistance, which grows with current and with the length of the run. A long run between array and controller can waste a real share of what the panels produce, and the fix is thicker conductor rather than more panels. Design targets are commonly held to a few percent of system voltage.
Related: Open-Circuit Voltage (Voc), Solar Panel
The process of identifying which households on a block have members who may need additional help during an emergency — people who live alone, have mobility limitations, depend on medical equipment, have young children, or don't speak English. Vulnerability maps are sensitive documents that should be maintained on paper by 2–3 trusted block coordinators and updated annually. The goal is to ensure no one is forgotten during an evacuation or outage.
Related: block captain, Map Your Neighborhood, communication tree
W
The pressure surge produced when moving water is stopped or slowed quickly, as when a valve closes fast. The rise equals the speed of the pressure wave in the pipe multiplied by the change in water velocity, divided by gravity, which means a modest system can briefly see several times its normal pressure. It is a common cause of burst pipe in both household plumbing and hydroelectric penstocks.
Related: Penstock, Hydraulic Head, Runaway Speed
A large underground pipe that carries treated drinking water from a distribution hub to neighborhoods and buildings. Water mains in the U.S. range in age from new installations to cast-iron pipes over 100 years old. The American Society of Civil Engineers estimates there are approximately 240,000 water main breaks per year in the U.S., resulting in the loss of roughly 6 billion gallons of treated water daily.
Related: distribution system, boil water advisory
A commercial sodium hypochlorite additive formulated to maintain a protective chlorine residual in stored water for up to five years when added at the manufacturer's specified dose at fill time. It addresses the natural dissipation of chlorine residual that occurs in tap water stored in sealed containers over months. One package typically treats up to 55 gallons and costs $10 to $15.
Related: Potable, HDPE (High-Density Polyethylene)
The practice of maintaining a supply of clean drinking water for use during disruptions to the municipal water system. The standard recommendation is one gallon per person per day for at least three days — covering drinking, cooking, and basic hygiene. Stored water should be replaced every six months if using tap water, or stored in commercially sealed containers with longer shelf lives.
Related: boil water advisory
A home preservation method in which sealed jars of high-acid food — fruits, pickles, jams, tomatoes with added acid — are processed in boiling water (212°F) for a specified time. Water-bath canning is safe only for high-acid foods (pH 4.6 or below); low-acid foods require pressure canning. The method has been used in American households since the 19th century and is documented extensively in USDA bulletins.
Related: pressure canner, National Center for Home Food Preservation (NCHFP)
A wheel turned by falling or flowing water, the oldest hydropower machine and still a practical one at very low head. Measured hydraulic efficiency of well-designed wheels reaches 75 to 85 percent, better than their reputation suggests. Their real limitation is rotational speed, since a large wheel turns at around ten revolutions per minute and driving a generator from that requires heavy gearing.
Related: Overshot Wheel, Micro-Hydro, Hydraulic Head
A unit of energy equal to one watt drawn for one hour. It measures the total energy a battery holds or a device consumes over time, which is the figure that decides whether a power station lasts the night. A full-size refrigerator uses roughly 1,000 to 2,000 watt-hours per day.
Related: Running Watts, Continuous Output, Duty Cycle
A barrier placed across a channel with a notch of known shape cut into it, so that the depth of water flowing over the notch corresponds to a calculable flow rate. Weirs are used to measure stream discharge repeatedly over a season, and low weirs also serve to raise water slightly at an intake without impounding any meaningful volume behind them.
Related: Cubic Feet per Second, Trash Rack, Forebay
An unplanned fire burning in natural vegetation — forests, grasslands, or brush. Wildfires can be ignited by lightning or human activity and may spread across thousands of acres when conditions align. The U.S. averages roughly 70,000 wildfires per year.
Related: Wildland-Urban Interface (WUI), defensible space, prescribed burn, fire behavior triangle
The zone where developed land — houses, businesses, infrastructure — meets or intermingles with undeveloped wildland vegetation. Homes in the WUI face elevated wildfire risk because fire can move directly from wildland fuels to residential structures. As of 2020, the WUI contains roughly 44 million U.S. homes — 32% of all housing.
Related: defensible space, Wildfire, fire-adapted community
A weather event bringing heavy snow, ice, freezing rain, or extreme cold over a wide area. Winter storms can collapse power grids, make roads impassable, and isolate households for days. Ice storms are particularly damaging to power infrastructure because ice accumulation on lines and trees causes widespread outages.
Related: generator interlock, rolling blackout
A public safety system that pushes short emergency alerts directly to cell phones in a targeted geographic area without requiring a subscription or app. WEA messages include AMBER alerts, severe weather warnings, and presidential alerts. WEA depends on cell tower coverage — if towers are down or the area lacks coverage, the alert will not reach phones in that zone.
Related: NOAA Weather Radio, evacuation order, Emergency Alert System (EAS)
A New Deal agency (1935–1943) that employed millions of Americans on public works projects during the Great Depression, including construction, arts, and writing. The WPA's Federal Writers' Project produced the 'America Eats' manuscripts documenting regional foodways and roughly 2,900 life-history interviews with ordinary Americans — both now invaluable primary sources for understanding Depression-era household economics.
Related: Federal Writers Project, Bureau of Home Economics, America Eats
This glossary is updated as the site grows. Last updated: 2026-07-27. 199 terms defined.
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Social Capital
The networks of relationships among people in a community that enable cooperation, trust, and collective action. In disaster research, social capital is the single strongest predictor of both survival and recovery — stronger than income, infrastructure quality, or government response speed. Neighborhoods where residents know each other by name evacuate faster, share resources more effectively, and rebuild more completely.
Related: mutual aid, communication tree, block captain