Safe water in Thailand: notices, drought and what to store

Short answer. In Bangkok, Nonthaburi and Samut Prakan, the Metropolitan Waterworks Authority (MWA) says its tap water is clean and safe to drink, and publishes monthly quality reports ¹². Phaenyx found no national system of boil-water notices in Thailand: ask your water authority (MWA 1125, PWA 1662) ¹⁴. Store at least 3 litres of drinking water per person per day, for at least 3 days ⁵.

How do I know if my tap water is unsafe?

MWA supplies Bangkok, Nonthaburi and Samut Prakan ². Elsewhere, the Provincial Waterworks Authority (PWA) runs a hotline, 1662 ⁴.

MWA publishes a water quality report every month ¹ and an online map of tap water quality values by district, branch area and monitoring station ³. Its FAQ gives a simple check: run the tap for a moment, look at a glass of water for clarity and smell it; a chlorine smell shows there is residual chlorine to kill germs ². It also says households must keep their own plumbing clean: replace old rusty iron pipes, do not pump directly from the mains, and clean storage tanks regularly ².

Phaenyx found no national register of boil-water or do-not-drink notices for Thailand. If water looks, smells or tastes wrong, call MWA on 1125 (24 hours a day) ¹ or PWA on 1662 ⁴, and follow their instructions. How official warnings reach you is on our Thailand alerts page. See What to do during a boil-water notice and Do-not-drink notices.

How much water should I store?

Government guidance for an emergency survival bag is "at least 3 litres of clean drinking water per person per day, for at least 3 days" ⁵. That is at least 9 litres per person. Full lists are on our Thailand emergency supplies page. See also How much water to store per person per day? and Water storage containers.

Is Thailand short of water?

In WRI's Aqueduct 4.0 model, the population-weighted median of Thai cities is in the "high" category for water stress today and in the 2050 business-as-usual projection, and "medium-high" for drought risk, on Aqueduct's separate drought scale ⁷. These are city medians: a given town can sit higher or lower.

Thaiwater.net, the National Hydroinformatics Data Center run by the Hydro-Informatics Institute (HII), a public organization, gathers water and weather data from the agencies concerned in one database, including a drought monitoring map ⁶. Phaenyx found no national page listing current water-use restrictions for households. See Drought preparedness and Living without running water.

What if I have a private well?

Phaenyx found no official Thai guidance for household wells. See Private well emergencies and Water purification.

What should I do after a flood?

Follow your water authority's instructions and see Water safety after a flood. A household plan can keep your water stock, local contacts and warning channels in one place.

Frequently asked questions

Is Bangkok tap water safe to drink?

MWA says that in Bangkok, Nonthaburi and Samut Prakan its tap water is clean and safe to drink, provided your building's pipes and tanks are kept clean ².

Where can I see test results?

MWA posts monthly water quality reports ¹ and an online quality map ³.

Who do I call about my water?

MWA Call Center 1125, 24 hours a day ¹; PWA hotline 1662 ⁴.

How much water for three days?

At least 3 litres per person per day, so 9 litres per person ⁵.

Sources

1. Metropolitan Waterworks Authority (MWA, การประปานครหลวง) — รายงานผลคุณภาพน้ำ (รายเดือน) — Water quality report (monthly) — https://www.mwa.co.th/knowledge/water-quality-information/water-supply-quality/quality-report-monthly/ (accessed 2026-10-27)
2. Metropolitan Waterworks Authority (MWA, การประปานครหลวง) — ถามตอบคุณภาพน้ำ — Water quality FAQ — https://www.mwa.co.th/knowledge/information-about-water/faq-water/ (accessed 2026-10-27)
3. Metropolitan Waterworks Authority (MWA, การประปานครหลวง) — ระบบตรวจสอบคุณภาพน้ำประปาออนไลน์ — Tap Water Quality Monitoring System (TWQMS) — https://twqonline.mwa.co.th/ (accessed 2026-10-27)
4. Provincial Waterworks Authority (PWA, การประปาส่วนภูมิภาค) — การประปาส่วนภูมิภาค (home page) — https://www.pwa.co.th/ (accessed 2026-10-27)
5. Narathiwat Provincial Public Relations Office, Government Public Relations Department (สำนักงานประชาสัมพันธ์จังหวัดนราธิวาส) — ถุงยังชีพฉุกเฉิน สิ่งของจำเป็นผู้ประสบภัยธรรมชาติ ต้องมีอะไรบ้าง? — https://narathiwat.prd.go.th/th/content/category/detail/id/9/iid/527646 (accessed 2026-10-27)
6. Hydro-Informatics Institute (HII, สถาบันสารสนเทศทรัพยากรน้ำ, public organization) — คลังข้อมูลน้ำแห่งชาติ — National Hydroinformatics Data Center (Thaiwater.net) — https://www.thaiwater.net/ (accessed 2026-10-27)
7. World Resources Institute (WRI) — Aqueduct 4.0 (water stress, 2050 projection and drought risk) — https://www.wri.org/aqueduct (accessed 2026-10-27)