12/04/2026
𝐈𝐧𝐟𝐞𝐜𝐭𝐢𝐨𝐧𝐬 𝐘𝐨𝐮 𝐂𝐚𝐧 𝐂𝐚𝐭𝐜𝐡 𝐟𝐫𝐨𝐦 𝐌𝐨𝐚𝐭 𝐖𝐚𝐭𝐞𝐫 𝐃𝐮𝐫𝐢𝐧𝐠 𝐒𝐨𝐧𝐠𝐤𝐫𝐚𝐧
The most iconic image of Songkran water fights in Chiang Mai: music, crowds, a slow-moving procession of trucks and pickup beds packed with people dousing each other and passersby from barrels of water. The convoy barely crawls — often it just stops entirely — along the moat surrounding the Old City. When the barrels run dry, they can be refilled straight from the moat for just 100 baht. Enterprising locals line the canal with hoses and portable pumps; those without pumps scoop water in buckets and sprint back and forth.
But how safe is that moat water, actually?
🏚️ 𝐖𝐡𝐚𝐭'𝐬 𝐢𝐧 𝐭𝐡𝐞 𝐌𝐨𝐚𝐭
The moat is an artificial canal encircling the Old City. It collects rainwater and street runoff, and occasionally receives sewage overflow and organic waste. Before Songkran, city authorities do make an effort: debris is cleared, the dirty water is pumped out and replaced with fresh water, and laboratory tests are conducted and publicly announced. In some years — 2014 and 2015, for example — elevated parasite counts led officials to declare the water unsafe. In recent years, the official line has been that the water is "safe for splashing, but not for drinking" — a phrase that tends to draw considerable skepticism, and outright mockery, from Chiang Mai locals.
At the very start of the festivities, the water may indeed be relatively clean. But as Songkran unfolds, thousands of people scoop water from the moat with buckets and barrels, drench each other, and the water drains right back in. The Old City's aged infrastructure is riddled with rat burrows — including in the moat walls themselves. As dirty water seeps back through those burrows, it becomes saturated with rat f***s. The longer the celebrations go on, the more contaminated the moat becomes.
⚠️ 𝐓𝐡𝐞 𝐑𝐢𝐬𝐤𝐬
🐀 𝙇𝙚𝙥𝙩𝙤𝙨𝙥𝙞𝙧𝙤𝙨𝙞𝙨 — the primary threat
Also known as rat fever or rat urine disease, leptospirosis is caused by Leptospira bacteria (mainly L. interrogans), shed in rat urine. The bacteria thrive in slow-moving or stagnant water, especially in Thailand's tropical climate. During Songkran, contaminated water splashes onto skin and mucous membranes — and the risk spikes sharply if you have any cuts or abrasions, or if water gets into your eyes or mouth.
🌡️ Symptoms appear 5–14 days after exposure: high fever, severe headache, intense muscle pain (particularly in the calves), chills, red eyes without discharge, nausea. In severe cases — Weil's disease — the infection can cause jaundice, kidney and liver failure, internal bleeding, and can be fatal without treatment.
This isn't a theoretical risk. Thailand reports hundreds to thousands of leptospirosis cases every year following rain, flooding, and water festivals. Doctors issue specific warnings about it during Songkran. The Old City moat — stagnant, rat-infested — is a textbook breeding ground.
𝐎𝐭𝐡𝐞𝐫 𝐰𝐚𝐭𝐞𝐫𝐛𝐨𝐫𝐧𝐞 𝐫𝐢𝐬𝐤𝐬
🤢 𝙎𝙖𝙡𝙢𝙤𝙣𝙚𝙡𝙡𝙤𝙨𝙞𝙨 — Salmonella bacteria from rat f***s contaminate the water and can be transmitted by swallowing even small amounts, or through unwashed hands. Expect diarrhea, vomiting, abdominal cramps, and fever.
🦠 𝙍𝙖𝙩-𝙗𝙞𝙩𝙚 𝙛𝙚𝙫𝙚𝙧 — caused by Streptobacillus moniliformis or Spirillum minus, these bacteria can spread not only through bites and scratches but also through water or food contaminated with rat f***s or urine. Symptoms include fever, rash, and joint pain; complications such as endocarditis are possible in severe cases.
🟡 𝙃𝙚𝙥𝙖𝙩𝙞𝙩𝙞𝙨 𝙀 (𝙧𝙖𝙩 𝙨𝙩𝙧𝙖𝙞𝙣) — Rocahepevirus ratti (rat HEV) is shed in rat f***s and spreads through contaminated water via the fecal-oral route. Cases of human infection have been documented across Asia, particularly in immunocompromised individuals. It presents as acute hepatitis: jaundice, fatigue, and liver pain.
🫁 𝙃𝙖𝙣𝙩𝙖𝙫𝙞𝙧𝙪𝙨 — primarily transmitted by inhaling aerosolized particles from dried f***s or urine, though contact with heavily contaminated water carries some theoretical risk. Rare in Thailand and Southeast Asia, but worth noting; it can cause severe pulmonary or renal disease.
✅ 𝐖𝐡𝐚𝐭 𝐭𝐨 𝐃𝐨
Tha Phae Gate and Moat Road are among the most atmospheric and exhilarating Songkran venues in all of Thailand. Bangkokians routinely make the trip north, insisting this is the real Songkran compared to the capital's version — and honestly, it's hard to argue. The chaos is spectacular.
But the moat water is another matter entirely.
💧 Use clean water — from bottles, hoses, or municipal supplies — not from the moat or street runoff.
🩹 Cover any cuts or abrasions with waterproof bandages before heading out.
👄 Keep water out of your eyes, nose, and mouth as much as possible.
🚿 Shower with soap after the festivities, especially if you were in the Old City area.
🏥 Watch for symptoms in the 1–3 weeks following Songkran. Fever combined with muscle pain and red eyes is a classic leptospirosis presentation — see a doctor immediately and mention your exposure to moat water in Chiang Mai. Leptospirosis is treatable with antibiotics (doxycycline or penicillin), but early treatment is critical.
If symptoms appear, don't try to tough it out or self-medicate. Chiang Mai has excellent clinics and hospitals staffed with doctors who know exactly what to look for after Songkran.
🎉 Celebrate hard — just leave the moat water out of it.