Bangkok's Late-September 2026 Floods and Thung Khru: What the Reports Say

According to Thai PBS, heavy rain on 25 and 26 September 2026 dropped more than 300 mm on Bangkok in roughly 48 hours, and all 50 districts were declared disaster areas on 26 September. On 29 September the DDPM declared flood assistance zones covering 38 districts and 118 subdistricts, and Krungthep Turakij, citing DDPM data from 6 October 2026, reported about 329,000 affected households in Bangkok.

For Thung Khru specifically, Thai PBS reported that on 29 September 2026 the DDPM listed Thung Khru subdistrict and Bang Mot subdistrict as flood assistance zones. Thansettakij reported that from 29 September to 4 October 2026 the Hydrographic Department warned of high sea tides and advised monitoring of Rama 2 Road and Suksawat Road.

What these sources do not give is a road-by-road or soi-by-soi water depth for Thung Khru. So we will not say how deep the water was, and we will not make up numbers. What we can honestly say is that the area was on the assistance list during a period when heavy rain coincided with a high-tide warning, a combination that slows the drainage of rainwater.

Flood Points in Thung Khru District as Reported

The places named clearly in our sources are:

• Thung Khru subdistrict: listed in the DDPM flood assistance zone declaration of 29 September 2026 (Thai PBS).
• Bang Mot subdistrict: listed in the same declaration on 29 September 2026 (Thai PBS).
• Rama 2 Road and Suksawat Road: named for monitoring in the high-tide warning for 29 September to 4 October 2026 (Thansettakij). This was a watch warning, not a water-level report.

Because no road-level depths were reported, we suggest picturing Thung Khru as an area dealing with "slow-draining rainwater" rather than deep, roof-high floods. That may sound mild, but from a hygiene point of view it has its own problems: drains that back up, sewage mixing with rainwater, and humidity that lingers in ground-floor rooms for days.

Example Case: A Ground-Floor Rental Building in Bang Mot and the Curry Shop at the Soi Entrance

The following is an example case written from common post-rain situations. It is not the account of a real person.

Fon manages a five-storey apartment building on a soi in Bang Mot. After two nights of heavy rain, she noticed the water in the drain channel out front was not going down the way it usually did. Grey, cloudy water began pushing up through the floor drain in the shared ground-floor bathroom, and a septic smell drifted into the corridor. Many tenants, students and office workers, had to wade through shallow water in the soi each morning to catch their ride.

A few days later the soi was dry, but the ground-floor rooms were still damp and small dark spots appeared low on the walls. One tenant had diarrhoea and vomiting. Another had a scraped foot that turned red and swollen. The curry-and-rice shop at the soi entrance closed for a day because the owner worried that water backing up from the kitchen drain might have contaminated dishes and prep areas.

Fon had the cleaning staff scrub the floors with floor cleaner and pour diluted bleach, but the musty smell stayed and some tenants still avoided the shared bathroom. Her question is the one many people in Thung Khru are asking: which germs should we fear most, and where do we start? Tenants who felt unwell were told to see a doctor first. For the building, the answer is in the ranking below.

How We Ranked Post-Flood Germs for Thung Khru District

To keep the ranking transparent, we used six criteria. Again, this is editorial weighting, not a calculation from patient statistics.

1. Fit with the local flood type. Thung Khru saw slow-draining rainwater during high tides, so we weighted germs linked to drains, sewage and damp ground-floor rooms.
2. How often it appears in flood guidance from WHO, CDC and the Department of Disease Control.
3. Severity of illness if infection occurs.
4. Local at-risk groups, such as ground-floor tenants, students sharing bathrooms, food vendors, older adults and small children.
5. Persistence in the environment, described qualitatively only. We do not quote survival times without a clear source.
6. Ease of spread through hands, surfaces, food or droplets.

Combined, these criteria give Thung Khru a different order from a mountain flash flood or a riverside area under water for weeks, because the key factor here is a drainage system under pressure from high tides and repeated rain.

Post-Flood Germ Ranking for Thung Khru District 2026: The Top 10

No. 1: Sewage Bacteria from Backed-Up Drains, E. coli (Escherichia coli) and Shigella

When high tides coincide with heavy rain, public drains empty slowly and wastewater from homes and septic tanks can push back up through bathroom floor drains, front channels and kitchen pipes. E. coli lives in human and animal intestines and is used as an indicator of sewage contamination; most types are harmless, but some cause severe diarrhoea. Shigella causes dysentery and spreads easily through hands and food.

They hide on shared bathroom floors, toilet rims, floor drains, kitchen sinks, eatery floors and wading shoes. Watch for diarrhoea, cramps, vomiting, fever or bloody stools; small children, older adults and people with weak immunity are most at risk, and anyone with symptoms should see a doctor. Wash hands with soap after contact, keep wading shoes outside, discard food touched by floodwater, and clean backflow areas with detergent before disinfecting. Both belong to the bacteria group CHEMGENE HLD4H says it covers in general, but WHD's pages list no test result for these two organisms; ask the team for organism-specific data.

No. 2: Norovirus in Shared Bathrooms and Kitchens

Rental buildings and dormitories in Bang Mot and Thung Khru often share bathrooms, laundries or kitchens. Norovirus causes sudden vomiting and diarrhoea and spreads very easily through hands, surfaces, food and vomit particles, so one sick tenant can quickly become several.

High-risk spots are door handles, taps, flush buttons, stair rails, lift buttons and common tables. Dehydration is the main danger for small children and older adults; follow medical advice and see a doctor if symptoms persist. Norovirus is listed on WHD's product page as covered by CHEMGENE HLD4H, according to the product information, which makes common-area spraying after cleaning a good fit for shared buildings, with tenants out of the zone until the technicians say they can return.

No. 3: Mould in Closed Ground-Floor Rooms, Aspergillus and Penicillium

Ground-floor rooms with few windows stay damp when water sits around the building and rain keeps falling. Moisture soaks into masonry, door frames, plywood, ceilings and mattresses. WHO and CDC advise drying out within 24 to 48 hours to limit mould.

Aspergillus and Penicillium spores can trigger allergies, sneezing and eye irritation and worsen asthma; people with weak immunity need extra care. Remove soaked materials that cannot be saved, clean and dry the rest, then disinfect. WHD's pages say the product covers fungi in general; ask for species-specific data. Ozone treatment can be added if a musty smell lingers.

No. 4: Vibrio and Wounds Exposed to Water During High Tides

Vibrio bacteria occur naturally in brackish and sea water, and CDC notes that open wounds exposed to such water, including coastal floodwater, can become infected. We rank it fourth because the heavy rain came with a high-tide warning, but no salinity was reported for Thung Khru, so this is precautionary, not a claim that Vibrio was found.

People with foot or leg wounds, liver disease, diabetes or weak immunity are most at risk. See a doctor quickly if a wound becomes red, swollen, hot, very painful or blistered. Cover wounds with waterproof dressings, wear boots, and wash wounds with soap and clean water after contact. Washing silt off entrances and ground floors, then spraying, reduces germs where people walk daily. WHD's pages list no specific result for Vibrio.

No. 5: Leptospira, the Cause of Leptospirosis

The Department of Disease Control warns about leptospirosis every flood season. The bacteria come from the urine of rats and some other animals, mix into water and mud, and enter through cuts or the eyes, nose and mouth. Around eateries, markets and rubbish piles, rats move closer to people when water rises.

It is fifth because reports describe slow drainage rather than weeks of deep water, but daily waders are still at risk. Sudden high fever, headache, severe calf pain and red eyes after wading mean you should see a doctor and mention the exposure. Wear boots, store rubbish securely, and clean rat-soiled areas wearing gloves, washing first and then disinfecting. No organism-specific result for Leptospira is listed; ask the team for more information.

No. 6: Hepatitis A Virus from Food, Ice and Utensils

Hepatitis A spreads by the faecal-oral route, and the risk rises when drain water reaches kitchens and utensils. Neighbourhoods full of curry shops and street stalls, as around Bang Mot, should treat kitchen hygiene as a priority.

Symptoms include tiredness, nausea, fever and upper-right abdominal pain, then yellow eyes and dark urine; the long incubation means people may not link it to the flood. See a doctor and ask about vaccination on medical advice. Use clean or boiled water, discard ice and suspect ingredients, wash and scald utensils, then spray non-food-contact areas as advised. Hepatitis A falls within the virus group the product covers broadly, without an organism-specific result online.

No. 7: Pseudomonas aeruginosa in Pipes and Bathrooms

Pseudomonas lives in drains, sinks and pipe slime, which repeated backflow spreads onto bathroom floors. It rarely troubles healthy people but matters for people with wounds, contact lens wearers and those with weak immunity. Possible problems include wound infections, skin rashes after soaking and ear infections. Scrub floor drains, sink rims and grout, then spray bathrooms and drain areas. No organism-specific result is listed online.

No. 8: Staphylococcus aureus in Soaked Wounds, Plus Tetanus Risk

Moving furniture and walking through debris leads to unnoticed scrapes. Staphylococcus aureus lives on many people's skin and can infect wounds left dirty, causing pus or boils. Wounds from soil-contaminated nails or sharp objects should be assessed for tetanus (Clostridium tetani); ask a doctor about vaccination, especially if your last shot is uncertain. Cleaning and then spraying rails, handles and tables reduces hand-to-hand spread.

No. 9: Skin Fungi, Ringworm and Athlete's Foot (Dermatophytes)

Wading daily and then wearing damp trainers leads to soggy, itchy skin between the toes. Dermatophytes spread via shared bathroom floors, mats and shoes. Wash and dry feet carefully, change socks often, and do not share shoes or towels; see a doctor if a rash spreads. Scrubbing and spraying shower floors helps, and fungi in general are a group the product says it covers.

No. 10: Influenza and COVID-19 (SARS-CoV-2) in Crowded Rooms

After a flood, tired people spend more time indoors, often crowded with relatives, so respiratory germs spread more easily. These rank last because they are less directly tied to floodwater. Watch for fever, cough and sore throat, wear a mask when ill, ventilate when the rain stops, and see a doctor if symptoms are severe. Influenza H1N1, H5N1 and SARS-CoV-2 are listed as covered on WHD's service and product pages, so spraying lobbies, lifts and common rooms helps reduce germs on shared touch points.

Why Soap, Bleach or Mopping Alone Falls Short

Cleaning with detergent and soap is the most important step and must always come first, because it removes mud, dirt and organic matter where germs hide. In practice, though, there are limits.

• Home-mixed bleach is often diluted unevenly. Too strong and it damages surfaces and irritates the airways; too weak and it may not work as intended. Never mix it with ammonia or acid products, which can release dangerous gases.
• Mopping misses places, such as under beds, behind cabinets, low on walls, in grout lines and around pipes.
• Common areas have many touch points, and wiping them one by one takes time and some get missed.
• Contact time matters. Wiping and rinsing straight away may not give a product the time its maker specifies.
• Fragrance and air fresheners only mask smells; they do not remove the cause.

That is why WHO and CDC give the same order: clean first, then disinfect surfaces touched by floodwater. Spraying by trained technicians is one way to make the disinfection step more thorough and even.

WHD Post-Flood Disinfection Spraying for Thung Khru District

World Health Disinfection is based in Bang Khae District, Bangkok 10160, on the Thonburi side like Thung Khru. Bookings are made by phone at 065-556-6294 or via LINE @whd268. We have no branch in Thung Khru and we do not promise same-day service, because post-flood scheduling depends on demand at the time.

According to the service information on our disinfection service page, trained technicians spray and/or ULV-fog (Ultra Low Volume, a very fine mist). The disinfectant is CHEMGENE HLD4H, a medical-grade product from the UK containing Benzalkonium Chloride and Didecyldimethylammonium Chloride. The service page lists viruses, bacteria and fungi, including COVID-19, RSV, H1N1, H5N1 and hand-foot-and-mouth virus, with a claimed efficacy of 99.99%. The product page states 99.85% against COVID-19 within one minute and lists further organisms such as norovirus, Salmonella, Bordetella pertussis and mycobacteria.

The website also lists approvals and references: the Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019. Customers named on the page include hospitals, schools, malls, airports, offices, airlines, banks and residential buildings. A promotion includes a free CHEMGENE spray bottle and WELLGIENIC wet wipes, and tax invoices are available.

WHD does not claim to kill every germ in the world and does not state a number of strains. We use the website's own wording, broad-spectrum. For organisms not listed on the site, customers can request organism-specific test data before deciding.

Service Steps

1. Contact and survey. Tell us the building type, area, number of rooms and post-flood condition, such as where drains backed up or where it smells musty, by phone or LINE with photos.
2. Prepare the area. You or a cleaning crew remove mud, wash surfaces, ventilate, and store food, utensils and personal items securely.
3. Zone and clear people. Tenants, staff and pets leave the zone being sprayed.
4. Spray. Technicians apply spray or ULV mist to the agreed surfaces and areas.
5. Wait and re-enter. According to the service information, wait about 30 minutes before normal use, following the re-entry time the technicians give on site.

WHD does not claim the spray leaves no residue. If you are concerned about food-contact surfaces, ask the technicians how to wipe them before use. Anyone who is ill should see a doctor first; disinfection is not medical treatment.

10 Reasons Buildings in Thung Khru Should Be Disinfected After Waterlogging

1. Sewage backs up through drains during high tides, contaminating ground-floor bathrooms and kitchens with gut bacteria.
2. Multi-unit buildings have shared bathrooms and touch points that pass germs along easily.
3. Eateries need confidence before reopening, and disinfecting after washing the kitchen helps them serve again with peace of mind.
4. ULV fine mist reaches corners that wiping misses. See the disinfection service page for details.
5. Medical-grade CHEMGENE HLD4H with clearly stated ingredients and listed organisms.
6. Trained technicians zone the area, control the amount of disinfectant and tell you when to return.
7. About 30 minutes of waiting according to the service information, so the building is back in use quickly.
8. Fewer worries for tenants and customers, meaning fewer complaints and move-outs.
9. Tax invoices available, useful for companies, dormitories and shops.
10. Also on the Thonburi side. Our office is in Bang Khae; book through the WHD team on 065-556-6294 or LINE @whd268.

Before and After Disinfection Spraying

Checklist for Homes, Rental Rooms and Shops in Thung Khru

Before Spraying

• Check electrical safety. If water came near sockets or the distribution board, have an electrician inspect first.
• Wear rubber gloves, boots and a mask while removing mud and rubbish.
• Discard food, ice, medicines and cosmetics touched by floodwater.
• Remove soaked materials that cannot be saved, such as mattresses, carpets and swollen ceilings.
• Wash surfaces with detergent and clean water, then open windows and run fans.
• Scrub floor drains, sinks and bathroom grout.

After Spraying

• Re-enter at the time the technicians give and ventilate.
• Wipe food-contact surfaces with clean water as advised before use.
• Watch for musty smells or new mould spots, and look for remaining moisture sources.
• Look after your health. Anyone with fever, calf pain, diarrhoea or an inflamed wound should see a doctor.
• Follow tide warnings and rain forecasts so you can raise belongings if heavy rain returns.

FAQ: Post-Flood Germ Ranking for Thung Khru District

1. How deep was the flooding in Thung Khru?

Our sources say the DDPM declared Thung Khru and Bang Mot subdistricts flood assistance zones on 29 September 2026, with a high-tide warning from 29 September to 4 October, but they give no road-level depths, so we do not state any.

2. Is this ranking official?

No. It is WHD's editorial ranking based on the criteria above and on WHO, CDC and Department of Disease Control guidance. It does not claim any germ was detected locally.

3. Should we spray now or wait until the high tides pass?

Clean and dry as soon as possible. Spraying works best after washing is finished and when water is not expected to come back in. If more waterlogging is likely within days, ask our team about timing.

4. Can you spray a rental room while people live there?

Tenants and pets must leave the sprayed zone during work and return at the time the technicians give; according to the service information, that is about 30 minutes.

5. Does WHD have a branch in Thung Khru?

No. Our office is in Bang Khae. Bookings are via 065-556-6294 or LINE @whd268, subject to the schedule, and same-day service is not guaranteed.

The rain has eased and the water is gone. Finish the job on germs in rental rooms, shops and homes in Thung Khru and Bang Mot

Call 065-556-6294 · LINE @whd268

Related Services

• World Health Disinfection spraying service
• CHEMGENE HLD4H disinfectant
• Residential and building ozone disinfection for musty smells after floods

References

• Thai PBS (29 September 2026), Bangkok flood assistance zone declarations: read the source
• Thansettakij, high-tide warning 29 September to 4 October 2026 for Rama 2 and Suksawat roads: read the source
• Thai PBS, Bangkok rainfall in late September 2026: read the source
• Krungthep Turakij, DDPM data on affected households in Bangkok: read the source
• CDC, Floods: read the source
• World Health Organization, fact sheets: read the source
• Department of Disease Control, Thailand: read the source