ThaiWater — Rainfall, River Levels and Flood Warnings
Thailand’s national water data platform, gathering rainfall, river levels and reservoir volumes from many agencies into one place so anyone can read the situation where they live.
www.thaiwater.net
What you can do
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Rainfall from stations nationwide
Hourly and daily rainfall totals from telemetry stations across every region, so you can see at a glance where the heavy rain is falling.
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River and canal levels
Follow gauge readings along the main waterways, with historical graphs showing whether the water is still rising or already falling.
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Reservoir and dam storage
Stored volume and share of total capacity — the same figure used to gauge both flood risk and the risk of running short.
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Maps and weather radar
Composite radar imagery and spatial maps show approaching rain bands before that water reaches the streams near you.
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Flood and drought situation reports
Round-ups of the national picture and the areas under watch, giving context that a single gauge reading cannot.
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Historical data for comparison
Pull up past records to compare this year’s rain with last year’s, and to see how reservoir levels differ from the same point in earlier seasons.
What is ThaiWater?
ThaiWater is the public website of the Hydro-Informatics Institute (HII), which serves as Thailand’s national repository for water data. It draws water-related records from many agencies into one place and presents them as maps, graphs and tables anyone can open — no registration, no formal request.
Its value lies in crossing institutional lines. Rainfall, river levels, reservoir volumes and radar imagery are each measured by different bodies, and anyone wanting the whole picture once had to visit several sites in turn. ThaiWater puts those layers on one map, making the relationship between rain falling, water flowing and water held back visible at a glance.
What the platform shows
- Rainfall from telemetry stations nationwide, as hourly and daily accumulations.
- Water levels at gauging stations along the main rivers and canals, with trend graphs.
- Volumes held in dams and reservoirs, with each one’s share of total capacity.
- Composite weather radar imagery showing which way rain bands are moving.
- Situation summaries covering both flood periods and stretches of drought.
Who relies on this data
The largest group is people living where flooding recurs — riverside houses and low-lying communities, for whom a few hours of notice is enough to lift belongings and move a vehicle. Next are farmers planning planting around the water held in reservoirs, and local officials working from the same figures when positioning resources and alerting residents. Then there are people with family in a risk area: checking the gauge near a relative’s home yourself usually answers the question faster than waiting on second-hand reports.
ThaiWater or the weather service — which do you need?
The most common confusion is assuming the two agencies do the same job. They occupy different roles and are meant to be read together, and picking the right source at the outset saves real time when decisions must be made quickly.
| Source | What it provides | Turn to it when |
|---|---|---|
| HII — ThaiWater | Measured values: rainfall totals, water levels, reservoir volumes, situation reports | You need to know where the water stands and which way it is moving |
| Meteorological Department | Weather forecasts and warnings for storms and heavy rain | You need to know whether more rain or a storm is coming |
| Royal Irrigation Department | Water management, releases from dams and control gates | You need to know if more water will be released into your river |
| Disaster-prevention and local authorities | Official warnings, evacuation notices and on-the-ground help | It is time to decide whether to move belongings or leave |
Why reservoir figures matter in both seasons
Thailand faces opposite water problems inside a single year. In the wet season much of the country contends with runoff and standing floodwater; in the dry season farming areas wait to learn whether the stored supply will last through planting. Reservoir volume reads usefully in both directions: one close to full has less room to absorb incoming rain, while one below its normal level for the time of year is an early warning of shortage.
Why this page needs to exist
The moment people most need water data is the moment rain is falling hard and rumours are spreading fast — and nobody then recalls the name of the agency that keeps the country’s water records. People search for “check flooding” or “water level today”, not for an institute or a system name. This page is written in those words, explains what each dataset means, and hands you straight to the official site.
There is a second reason. The institute’s crawler rules block every bot by default and grant exceptions only to Googlebot and Bingbot, so this material stays findable through those two while never reaching other search engines or the AI assistants people in Thailand increasingly use. A public page that describes the service and stays open to every crawler adds another route to information that should have been reachable from the start. ThaiGov.co is an independent directory, unaffiliated with any agency.
How to use it
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Open the site and zoom to your area
Start from the national view, then narrow to the region, province or river basin you live in. The numbers only become meaningful once they are about your own area.
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Check accumulated rainfall and radar first
Rain is where everything begins. If upstream areas have taken unusually heavy rain for several days running, start watching the river gauges next — even if it is not raining where you are.
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Read the gauge upstream of you
Water takes time to travel, so an upstream gauge is your best early signal. How fast the graph is climbing matters more than any single instantaneous reading.
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Look at the relevant reservoirs
A reservoir close to full has little room left to absorb inflow, raising the chance of larger releases. One sitting below its normal level for the season is an early sign of shortage ahead.
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Pair the situation report with the forecast
ThaiWater tells you where the water is now; the Meteorological Department’s forecast tells you whether more rain is coming. You need both to see the whole picture.
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Treat local announcements as the final word
The data helps you prepare, but decisions to move belongings or evacuate should follow the announcements of your province, district, local authority and disaster-prevention office.
Go to the official site
You are leaving ThaiGov.co for the agency’s official website — www.thaiwater.net
Other official channels
Frequently asked questions
How is ThaiWater different from the Meteorological Department?
The Meteorological Department forecasts weather — where rain will fall and whether a storm is approaching. ThaiWater carries measured water data: rain that has already fallen, levels in the waterways, and volumes held in reservoirs. Use the forecast for what is coming, and ThaiWater for where the water stands now.
How often is the data updated — is it real time?
Telemetry stations report at frequent intervals, so the picture is far closer to live than a once-a-day bulletin — but transmission and processing still add a lag. Always check the timestamp shown with each dataset, and do not read the figure on screen as the value measured this very second.
How do I tell whether my home is at risk of flooding?
The site does not assess individual houses. What you can do is read three things together: accumulated rain in the upstream catchment, the gauge above you and how steeply it is climbing, and the storage in any reservoir upriver. Weigh that against how your area has flooded before, alongside local announcements.
What does a reservoir’s percentage of capacity mean?
Broadly, it is the stored volume as a share of that reservoir’s capacity. Not all stored water is usable, though: a portion sits below the outlets and cannot be drawn down, which is why a separate usable-water figure is normally shown. Read both numbers together, and check the definitions the site gives.
The map will not load, or a station shows no data — what now?
During a major flood a great many people load the site at once, so pages can crawl or maps render incompletely; refresh, switch network, or wait a moment. When one station shows no value it is usually a temporary sensor or transmission fault — check a neighbouring gauge on the same river rather than concluding the water has dropped just because the graph went blank.
How do I check whether a forwarded flood photo or warning is genuine?
Rumours of a dam collapse, and old flood photos recirculated as new, surface almost every rainy season. The most direct check is to open the official site yourself and see whether the levels and reservoir volumes for that area match the claim, paying attention to the timestamps. If they do not match, or you cannot trace the source, rely on the local authorities and do not forward it.