The correct order for cleaning up after a flood is: first confirm that the water has receded and that electricity and gas are safe, then photograph the damage as evidence, then clear out garbage and mud, wash with soapy water, and only last disinfect; power is restored only after everything is dry and a qualified electrician (合格電工) has inspected it. The two most common consequences of getting the order wrong are washing away the water marks without documenting them, or switching the power on without an inspection. Below is a timeline, with each row expanded afterward.
Post-flood cleanup timeline
The "24 to 48 hours" target comes from the disaster guidance of the US Centers for Disease Control and Prevention (US CDC); the public documents of the Taiwan Centers for Disease Control (Taiwan CDC) do not set an overall drying time, so the timing in the other columns is the order of the tasks, not an officially set number of days.
| Stage | When | Main actions | Don't do yet |
|---|
| 0. Safety check | After the water recedes, before entering | Confirm the water has receded and there is no obvious structural damage; if the main breaker is in a dry place, switch it off first, and keep the power off the whole time until an electrician has inspected; leave if you smell gas | Do not wade through standing water to reach a power switch |
| 1. Document | Before you start cleaning | Photograph the water marks, measure their height, photograph the damaged items | Do not wash the walls or mop first |
| 2. Clear out | Start right after documenting | Put on protective gear; clear garbage, mud and soaked debris first | Do not go barefoot or wear slippers |
| 3. Clean | After clearing out | Scrub walls, floors and furniture surfaces with soapy water | Do not spray bleach right at the start |
| 4. Disinfect | After cleaning | Disinfect at the dilution ratio, starting with places that touch food | Do not mix cleaning products |
| 5. Dry | As soon as possible, counting from when the water recedes (the US CDC target is to deal with wet items within 24 to 48 hours; the clock does not wait until disinfection is finished) | Open windows for ventilation, soak up water with towels and mop dry; items that cannot be washed and dried are recommended to be thrown away | Do not cover wet floors with carpet or boards |
| 6. Inspect and restore power | After drying | Have a qualified electrician inspect before switching the power on | Do not try the main breaker yourself |
| 7. Follow-up check | About a week later (suggested practice) | Look for mold spots and odors; empty containers holding standing water; check the drinking water | Do not feel safe just because the surfaces look dry |
Stage 0: confirm three things before entering
- Electricity: The US CDC guidance is blunt: do not turn power on or off yourself, or use appliances, while standing in water; when the main breaker is blocked by standing water, have an electrician come to cut the power; electrical equipment must be completely dry before it is used again. If the main breaker is in a dry place and has not touched water, switch the main breaker off before entering the house, keeping your hands dry; keep the power off throughout the cleanup until an electrician has inspected, and avoid outlets and the distribution box when scrubbing walls. How to judge appliances and outlets is outside the scope of this article; see Safety checks for water-damaged appliances.
- Gas: If you smell gas, do not switch any appliance on or off; close the gas valve, open the windows, leave the premises, and call 119 or the gas company from outside. The detailed steps are in Emergency steps for a gas leak.
- Structure: The US CDC recommends that if the house is damaged, a building inspector confirm it is safe before you enter. If walls are widely cracked, the ceiling is sagging or the floor has collapsed, do not go in yet; contact the local office (公所).
In addition, it is best to enter during the day, and to use battery-powered flashlights; do not use candles or open flames for light.
Stage 1: document, the 10 minutes before cleanup
The water marks on the walls and the thickness of the mud are the evidence for later applications for relief and insurance claims, and they disappear the moment cleanup begins. How to take the photos and which documents to prepare are covered separately in Applying for disaster relief at the local office, and documenting damage; here is just one reminder: photograph first, measure first, and only then start washing.
Stages 2 to 4: clear out, clean, disinfect; do not change the order
Taiwan CDC's anti-epidemic mnemonic is the three steps "clear out, clean, disinfect", and the older announcement of the Ministry of Health and Welfare says the same: after the water recedes, first put on gloves and rubber boots and clear out the garbage, then wash walls, floors and furniture surfaces with soapy water, and only last disinfect with bleach. Taiwan CDC documents also put disinfection last; for example, courtyards and drains are to be disinfected "after garbage is removed and the area is swept and cleaned", so do not skip around.
What to wear
Taiwan CDC's press release of August 2025 asks for waterproof gloves, long boots and also a mask, to avoid breathing in contaminated dust or droplets; the 2013 announcement further warns never to clean barefoot or in slippers, and to watch out for stab or cut wounds from rusty items such as nails and metal sheets. After cleanup, wash your hands with soap and clean water and check yourself for wounds.
How to dilute bleach
The table below gives the ratios written in the public documents of Taiwan CDC and the Ministry of Health and Welfare. The documents range from 2004 to 2025, but they are consistent when converted: about 100 cc per 10 liters of water is 500 ppm, roughly a 100-fold dilution. Before you use it, check the concentration and instructions on the label of the bleach you actually have.
| Use | How to dilute | Source and year |
|---|
| Floors, walls, toilets, bathrooms, kitchens, bedrooms | About 100 cc of household bleach sold in stores (500 ppm chlorine) per 10 liters of water; scrub thoroughly after sweeping clean | Taiwan CDC announcement of 2004; the 2025 press release says "wipe with a 100-fold dilution" |
| Tableware and cookware that cannot be boiled | About 40 cc per 10 liters of water (200 ppm), soak for 30 minutes or more; boil whatever can be boiled | Taiwan CDC announcement of 2004; the 2025 press release likewise says 40 ml per 10 liters of water, with a rinse in clean water after disinfecting |
| Courtyards, drains and other damp places | About 200 cc per 10 liters of water (1,000 ppm), sprayed after garbage is removed and the area is swept, taking care to protect your eyes and skin | Taiwan CDC announcement of 2004, Ministry of Health and Welfare announcement of 2008 |
Safety warning: Do not mix bleach with ammonia or products containing ammonia (the US CDC warns about this explicitly), and do not casually mix it with other cleaning products; open the windows for ventilation when spraying. Pouring in several cleaners at once does not make them work better, it only adds danger.
Priority: disinfect the places that touch the mouth first
If time is limited, do the places that touch food and children first: the dining table, the kitchen counter, cupboards, and the floors where children play. Kitchen utensils and tableware that have been under water must be disinfected before use; do not eat food that has been under water or that has thawed for too long during a power outage. For details, see Food safety in the fridge after a power outage.
Stage 5: drying is the key to preventing mold
Finishing disinfection does not mean you are done. The US CDC gives two versions: one page says to wash and dry or discard wet items "within 24 to 48 hours", while another page says 48 to 72 hours. The two differ, so take 24 to 48 hours as the conservative target, and the sooner the better. What you can do:
- Open the windows to keep damp places ventilated (the US CDC says explicitly to keep wet areas ventilated). Until an electrician has confirmed it is safe, do not use plug-in dehumidifiers, electric fans or extension cords; deal with the moisture by opening windows and soaking up water with towels for now.
- For wet items that cannot be repaired and cannot be washed and dried quickly, the US CDC recommends throwing them away. Mattresses and sofa cushions that have been flooded absorb a lot of water and are mostly hard to wash and dry, so discarding them is recommended.
- If the basement has standing water, the announcement of the Ministry of Health and Welfare recommends pumping it out promptly and keeping it dry.
- How large water-damaged furniture and appliances are collected, and whether there is a fee, differs among the environmental protection bureaus and the cleaning teams of the local offices in each county and city; please confirm with your county or city environmental protection bureau or the local office's cleaning team. Book by phone first, and do not pile the items directly in the arcade walkway or at the roadside.
For mold on walls afterward, and how and when to patch the silicone, see Wall efflorescence and peeling (壁癌) after a typhoon, and the timing of caulking.
Stage 6: when you can restore power
There are three conditions for restoring power, and none of them can be left out:
- The house is dry, there is no standing water, and there is no moisture around the outlets and the distribution box.
- Outlets, circuit breakers and distribution panels that have been under water have been inspected by a qualified electrician; whether to replace them is the electrician's judgment. For the standards for testing and replacement, see Drying out flooded outlets and insulation testing.
- If the electricity meter or the service-entrance equipment is damaged, contact Taipower to deal with it and do not touch it yourself; for how to look up outages and restoration, see Taipower outage lookup and what to do.
Even if the electrician says the power can be turned on, you are advised to stand in a dry place with dry hands when switching on the main breaker. For how to power appliances back on in batches after restoration, see Protecting appliances after power is restored.
Stage 7: drinking water and health
- Water storage tanks and rooftop water tanks: Taiwan CDC documents state plainly that if a water storage tank (蓄水池) has been invaded by sewage, it must be thoroughly washed and disinfected before storing water again, and the water must be boiled thoroughly before drinking, or you should drink bottled water. For cleaning a rooftop water tank, also see Rooftop water tanks and muddy water after a typhoon.
- Breeding sources: Taiwan CDC's 2025 reminder after rain is "inspect, empty, clear, scrub" (巡、倒、清、刷): pour out the standing water in containers inside and outside the home and clear them out thoroughly.
- Seeking care: The 2013 Taiwan CDC announcement lists fever, headache, muscle pain, abdominal pain, diarrhea, jaundice and fatigue as symptoms for which you should seek care promptly, telling the doctor on your own that you have been in contact with sewage or mud and how your wound came about; the elderly, people with chronic illness, weakened immunity or skin injuries should avoid skin contact with sewage or mud.
When not to tough it out yourself
- If you smell gas or hear a hissing sound: leave the premises and call 119 or the gas company.
- If the structure is cracked or damaged, the distribution box has been under water, or the electricity meter is damaged: do not touch anything; contact a qualified electrician, Taipower or the local office.
- If you get a fever after a wound came into contact with sewage: seek medical care and explain the exposure.
- To check which areas still have standing water or warnings, see the real-time flood dashboard.
Last updated: 2026-10-26
Sources
- Taiwan Centers for Disease Control (Taiwan CDC), Ministry of Health and Welfare, Recent heavy rain has caused standing water or flooding in many places; please follow the three anti-epidemic steps (2025) (in Chinese): masks, boots and gloves; 100-fold dilution; 40 ml per 10 liters of water; washing, disinfecting and boiling for water storage tanks; inspect, empty, clear, scrub.
- Taiwan CDC, Ministry of Health and Welfare, After a flood, clean your home and watch hygiene (2013) (in Chinese): never go barefoot or in slippers; wounds from rusty items; symptoms for seeking care; do not eat food that has been under water.
- Taiwan CDC, Ministry of Health and Welfare, After floods, guard against outbreaks of infectious disease (2004) (in Chinese): 200, 500 and 1,000 ppm, with the matching uses and dilution amounts.
- Ministry of Health and Welfare, Anti-epidemic measures after Severe Typhoon Sinlaku (2008) (in Chinese): the order of clearing out garbage first, washing with soapy water, and disinfecting last; pump out standing water in basements and keep them dry.
- US CDC, Reentering Your Flooded Home: power is restored only after an electrician's inspection; electrical equipment must be completely dry; a building inspector confirms the structure; gas handling.
- US CDC, Dry Off Wet Items After a Storm: wash and dry or remove wet items within 24 to 48 hours.
- US CDC, Preventing Mold: keep areas ventilated; discard wet items that cannot be repaired; never mix bleach with ammonia; this page says 48 to 72 hours, which differs from the previous page.
