The tap stops. This is not a question of whether — it is a question of when and for how long. Municipal water systems require electric pump stations to move water through distribution pipes. When the grid fails, those pumps stop within hours. Gravity-fed systems from elevated reservoirs can supply water for a day or two without power. Anything beyond that, and the tap is dry.
What you do in the hours before and the days after that moment determines your household’s water security for the duration. Water is not a problem you solve once — it is a system you manage continuously. Finding it, treating it, storing it, rationing it, and protecting it from contamination are four distinct activities that overlap and repeat for as long as the infrastructure remains down.
This post is the operational protocol — not the builds (those are in DIY Schematics) but the decision-making framework for water management when municipal supply is gone. What sources exist, how to evaluate them, how to treat each type, how much to store and how to ration it, and what the failure modes look like so you can identify them before they become crises.
THE WATER PRIORITY SEQUENCE
When municipal water fails, work through this sequence in order. Do not skip ahead and do not assume a lower-priority source is adequate before you have exhausted higher-priority ones.
Priority 1 — Stored water. The water you stored before the event. No treatment required beyond what was done at the time of storage. This is your most reliable, cleanest, most immediately accessible water supply. It should be your first draw and the last you exhaust, because replacing it requires more work than every other source combined. Start consuming from it immediately while you establish ongoing production from lower-priority sources.
Priority 2 — Municipal tap (while it lasts). Fill every available container the moment an extended outage appears likely. Do not wait. Bathtubs, pots, buckets, WaterBOB bladders, sealed containers. Once pressure fails, this source is gone until infrastructure is restored. Every gallon captured before pressure drops is a gallon you do not have to produce from a field source.
Priority 3 — Rain collection. The most reliable ongoing production source for most households. Clean roof collection with first flush diversion requires minimal treatment — sediment filtration and either gravity filter or boiling. See Rain Barrel System in DIY Schematics for the collection infrastructure. The protocol here is management: know your collection rate, know your dry-period storage, and never let stored rain barrel water drop below a two-week supply without active rain collection in progress.
Priority 4 — Well water (hand pump). If your property has a well with a hand pump conversion, this is your most reliable ongoing source and your highest-quality field water. Well water quality varies by location but is generally superior to surface water. Test annually, treat as needed based on test results, manage pump maintenance. See Hand-Pump Well Conversion for the infrastructure.
Priority 5 — Natural surface water. Streams, rivers, ponds, springs. Available in most rural and many suburban environments. Requires full treatment before drinking — this water carries biological contamination as a baseline assumption, and may carry chemical contamination depending on watershed. Treatment protocol below.
Priority 6 — Improvised production. Solar stills, transpiration bags, snow melt, dew collection. Low volume, labor-intensive, climate-dependent. The last resort that buys time while better sources are developed.
DAILY WATER BUDGET
Before you can manage water, you need to know how much you need. These are not comfortable living quantities — they are functional survival quantities for different use scenarios.
| Use Case | Per Person Per Day |
|---|---|
| Drinking only (sedentary, cool conditions) | 0.5 quarts minimum, 1 quart functional |
| Drinking and cooking | 1 gallon |
| Drinking, cooking, basic hygiene | 3 gallons |
| Drinking, cooking, hygiene, sanitation | 5 gallons |
| Full normal household use | 50-100 gallons |
The gap between 1 gallon and 100 gallons is what collapses when infrastructure fails. You are managing a transition from 100 gallons per person per day to 3-5, and every household system that previously used water — toilets, washing machines, dishwashers, showers, garden irrigation — must be rethought in that context.
Absolute minimum: 1 gallon per person per day for drinking and cooking. Below this threshold, dehydration begins degrading function within days and becomes medically serious within a week in temperate conditions, faster in heat.
Functional minimum: 3 gallons per person per day. Drinking, cooking, handwashing after toilet use, minimal personal hygiene. This is the planning quantity for a sustained event.
Planning buffer: Calculate 3 gallons per person per day and add 25% for cooking water, spilled water, and unexpected need. A household of four needs approximately 15 gallons per day. A 30-day supply requires 450 gallons. A 90-day supply requires 1,350 gallons.
SOURCE EVALUATION
Not all water sources are equal and not all contamination is the same. Before treating any field water source, evaluate what the likely contamination profile is — it determines which treatment method is necessary and whether the source is usable at all.
Biological contamination — bacteria, viruses, protozoa — is present in virtually all surface water and in any groundwater with nearby agricultural or septic activity. It is the most common contamination and the most reliably addressed by treatment: filtration removes bacteria and protozoa, boiling or UV treatment kills viruses.
Agricultural chemical contamination — nitrates (fertilizer runoff), herbicides, pesticides — is present in streams and groundwater in farming areas, particularly in the Midwest. Nitrate contamination is particularly dangerous for infants. Filtration does not remove it. Activated charcoal has limited effectiveness. Distillation removes nitrates. Reverse osmosis removes nitrates. If you are in an agricultural area — which Haven is — test your water sources for nitrates before relying on them.
Industrial chemical contamination — PFAS, heavy metals, petroleum products, solvents — is found near industrial sites, railroads, former manufacturing areas, and PFAS-contaminated watersheds (which now includes most of the US via atmospheric deposition). Filtration does not address most industrial chemical contamination. Activated charcoal adsorbs some organic chemicals. Distillation removes most but not all volatile organic compounds. If industrial chemical contamination is possible, the source is not appropriate for improvised treatment and should be avoided if alternatives exist.
Salinity — saltwater or high-mineral groundwater — requires distillation to make potable. Standard filtration and boiling do not remove dissolved salts or minerals. The solar still and improvised distillation still in DIY Schematics address salt water.
Radiological contamination — following a nuclear event — requires specialized treatment beyond the scope of this post and beyond the capabilities of improvised systems. Avoid all surface water sources in a confirmed radiological contamination area.
Source Quality Hierarchy
| Source Type | Biological Risk | Chemical Risk | Treatment Needed |
|---|---|---|---|
| Stored treated water | None | None | None |
| Collected rainwater (clean roof) | Low | Low | Sediment filter + gravity filter or boil |
| Well water (deep, tested) | Low | Low-moderate | Per test results |
| Springs | Low-moderate | Low | Gravity filter + boil |
| Moving streams (clean watershed) | Moderate | Low-moderate | Gravity filter + boil |
| Ponds and lakes | High | Moderate | Gravity filter + boil + consider distillation |
| Slow/stagnant water | Very high | Moderate | Gravity filter + boil; consider avoiding |
| Agricultural runoff areas | High | High | Distillation + charcoal; test first |
| Urban/industrial runoff | High | High | Avoid if possible; distillation + charcoal |
| Floodwater | Very high | High | Avoid for drinking; distillation only option |
TREATMENT METHODS
Sediment Pre-Filtration
Before any other treatment, remove large particles and turbidity. Turbid water — visually cloudy or brown — interferes with all chemical treatment methods and clogs mechanical filters. Pre-filter through a coffee filter, clean cloth, or fine-weave fabric into a clean container. Let it settle for 30 minutes if time permits.
This is not a treatment step — it is a preparation step. Pre-filtered water still requires full treatment.
Boiling
The most reliable and universally available biological treatment. Bring water to a rolling boil and maintain for 1 minute (3 minutes above 6,500 feet elevation). This kills all biological pathogens — bacteria, viruses, protozoa — regardless of concentration or type.
Boiling does not remove chemical contamination, heavy metals, or dissolved solids. It increases concentration of dissolved minerals slightly as water volume reduces. It is the correct treatment for biological contamination from clean natural sources.
Fuel cost: approximately 10 minutes of rocket stove operation per gallon boiled, including time to reach boiling. At 3 gallons per person per day for a household of four, boiling all drinking water requires approximately 2 hours of stove operation per day. This is manageable but represents a significant ongoing fuel commitment.
Gravity Filtration
A properly built gravity filter (see Gravity Water Filter Build in DIY Schematics) removes sediment, bacteria, protozoa, and with an activated charcoal stage, many dissolved chemicals and taste/odor compounds. A ceramic filter element at 0.2-0.5 micron removes 99.9%+ of bacteria and protozoa. It does not reliably remove viruses.
Gravity filtration is the correct primary treatment for collected rainwater and clean well or spring water. For surface water from unknown or higher-risk sources, combine filtration with boiling or UV treatment to address the full biological spectrum including viruses.
Chemical Treatment — Bleach
Unscented household bleach (sodium hypochlorite, 8.25% concentration) disinfects water when added in correct doses. It kills bacteria and viruses but is less effective against Cryptosporidium, which is resistant to chlorine.
Dosing: 8 drops (approximately 0.5 ml) of 8.25% bleach per gallon of clear water. 16 drops per gallon if water is cloudy. Stir, wait 30 minutes before drinking. Treated water should have a faint chlorine smell — if no smell after 30 minutes, add another dose and wait 15 more minutes.
Bleach has a limited shelf life — sodium hypochlorite degrades over time, more rapidly when exposed to light and heat. Store bleach in a cool, dark location. Replace annually. Check concentration: bleach that smells very weak or has been stored for more than a year may have degraded below effective concentration.
Bleach treatment is appropriate for short-term treatment of water from reasonably clean sources. It is not a substitute for filtration for heavily contaminated sources.
Chemical Treatment — Iodine and Chlorine Dioxide
Iodine tablets (Potable Aqua, Globaline) and chlorine dioxide tablets (Aquatabs, Katadyn Micropur) are compact, lightweight, and effective against bacteria, viruses, and (chlorine dioxide only) Cryptosporidium. Iodine has a long shelf life and is highly effective but has an unpleasant taste and is contraindicated for pregnant women and people with thyroid conditions. Chlorine dioxide is more expensive but has no taste issues and broader spectrum effectiveness.
Both are appropriate for field use and short-term emergency treatment. Neither is a primary household-scale water treatment method — the cost per gallon is too high for treating 3+ gallons per person per day on an ongoing basis.
UV Treatment
Ultraviolet light at germicidal wavelengths (254 nm) kills biological pathogens by damaging their DNA, preventing reproduction. UV pens (SteriPen, Aqua UV) are battery-powered, treat a liter in 60-90 seconds, and are effective against bacteria, viruses, and Cryptosporidium.
Limitations: UV does not work in turbid water — particles block UV penetration and pathogens can “hide” in the shadow of a particle. Pre-filter to clarity before UV treatment. Battery-dependent — plan for battery management in a sustained event. Does not address chemical contamination.
Distillation
Boiling water and condensing the steam produces distilled water free of biological contamination, dissolved solids, heavy metals, and most chemical contamination. The improvised distillation still in DIY Schematics produces 2-4 liters per hour from a contaminated source. Appropriate when the source water has chemical contamination concerns, high dissolved solids, or salinity.
Distillation requires fuel — plan accordingly. At 2 liters per hour of stove operation, producing 12 liters (3 gallons) requires 6 hours of fuel. This is a high fuel cost for a primary water treatment method but is the only option for chemically contaminated sources.
STORAGE MANAGEMENT
Container selection: Food-grade polyethylene containers only for water storage. The HDPE plastic marked with the recycling symbol 2 is appropriate. Glass is excellent but heavy and breakable. Do not use containers that previously held non-food substances — chemical residues are not removable by rinsing. Blue 55-gallon barrels, WaterBOB bladders (fits in a bathtub, 100 gallons), BPA-free stackable containers (WaterBrick, Scepter military cans), and standard food-grade 5-gallon buckets all work.
Water treatment before storage: Tap water contains residual chlorine that inhibits bacterial growth during storage. If storing tap water, no additional treatment is needed for storage up to 6 months if the container is sealed and stored in a cool, dark location. If storing filtered or boiled field water, add 2 drops of 8.25% bleach per gallon before sealing to provide residual disinfection during storage.
Storage conditions: Cool, dark, away from chemicals and petroleum products (HDPE absorbs VOCs from nearby sources over time). Off the floor if possible — temperature differential at floor level increases condensation inside containers.
Rotation: Rotate stored water annually — use it in cooking, gardening, and household use, then refill from tap. Water does not “expire” but the residual chlorine dissipates over 6-12 months and stored water is at higher biological risk after that without retreatment.
Labeling: Every container gets a label with fill date and treatment method. This is not optional — in a sustained event when you are pulling from multiple containers of different ages and sources, the label is the information that determines whether the water is safe.
CONTAMINATION RECOGNITION
Stored or treated water can become contaminated during storage or after treatment. Recognize the signs:
Visual: Cloudiness, color change, visible particles, film on the surface. Any visual change in stored water that was previously clear is a contamination indicator.
Odor: Rotten egg smell (hydrogen sulfide — bacterial activity), sewage smell, chemical smell, strong earthy/musty smell. Faint chlorine smell is normal in bleach-treated water and is not a problem. Any other odor in stored water is a problem.
Taste: Metallic, chemical, bitter, or sour taste in water that was previously neutral. Trust this signal.
Container integrity: Cracks, bulging (bacterial gas production), compromised seal, UV-degraded plastic becoming brittle and discolored.
If any of these signs are present, re-treat or discard the water. The caloric cost of reduced food intake is recoverable. Waterborne illness in a grid-down scenario — without access to IV fluids, antibiotics, or medical care — is life-threatening. Do not take risks with water quality.
WATERBORNE ILLNESS — RECOGNITION AND RESPONSE
Know the timeline and symptoms so you can identify waterborne illness quickly and respond before dehydration becomes severe.
Giardia: 1-3 week incubation. Chronic diarrhea, greasy floating stools, gas, nausea, fatigue. Responds to metronidazole (requires prescription) or tinidazole. In the absence of medication, supportive care — oral rehydration, rest, continued clean water intake — and the infection typically resolves in 4-6 weeks in healthy adults.
Cryptosporidium: 2-10 day incubation. Watery diarrhea, cramping, nausea. Self-limiting in healthy adults — 1-2 weeks. Nitazoxanide is effective (prescription). Immunocompromised individuals may develop prolonged, severe illness — this is a medical emergency requiring evacuation to care if at all possible.
Bacterial contamination (E. coli, Salmonella, Campylobacter): 6 hours to 3 days incubation depending on organism. Nausea, vomiting, diarrhea (sometimes bloody for E. coli O157:H7), fever, cramping. Most cases resolve in 5-10 days in healthy adults with adequate hydration. Bloody diarrhea with fever requires medical care if accessible — it indicates possible hemolytic uremic syndrome which can be fatal.
Oral rehydration: The critical intervention for any diarrheal illness is preventing dehydration. ORS (Oral Rehydration Solution) — available as Pedialyte, WHO-formula packets, or improvised (1 liter clean water, 6 level teaspoons sugar, ½ teaspoon salt) — replaces electrolytes lost in diarrhea and prevents the dehydration that kills. Drink continuously. Keep producing clean water.
FINAL THOUGHTS
Water management in a grid-down scenario is not a one-time action. It is a daily practice — producing, treating, storing, rationing, monitoring, and protecting clean water continuously for as long as the event lasts. The household that builds this practice before the event, with the infrastructure already in place and the protocols already understood, manages it as routine. The household that figures it out after the tap stops is managing a crisis.
The builds are in DIY Schematics. The math is in The Storage Blueprint. This is the operational layer — the decision framework that connects the infrastructure to the daily practice. Use all three together.
Water first. Always water first.
For rain collection infrastructure, see Rain Barrel System in DIY Schematics. For water filtration builds, see Gravity Water Filter Build in DIY Schematics. For well access without power, see Hand-Pump Well Conversion. For emergency water production from soil and vegetation, see Solar Still — Water Collection. For storage targets, see The Storage Blueprint in the Field Rations Archive. For what contamination does to the body long-term, see Know Your Water on kanafia.com.