Everything on this site is also available as plain data. It is free, needs no key and allows any website to read it. Levels are in feet; a missing figure is empty, never zero. Last updated 2026-10-24.
Level now, the three official flood marks, status, trend and time of reading for every gauge. Refreshed every minute; the gauges themselves report about once an hour.
GET https://waterlevels.lk/api/levelsGET https://waterlevels.lk/api/levels?station=hanwellaGET https://waterlevels.lk/api/levels?river=kelani-gangaGET https://waterlevels.lk/api/levels?town=wellampitiyaEach record has level, nextHour (below), unit (ft), marks (alert, minor, major), status (normal, watch, alert, minor, major, none, stale), trend, observedAt (ISO 8601, with ageMinutes) and the page url. published keeps the figure exactly as the agency released it.
Every gauge in /api/levels carries nextHour: where the river is expected to be in about an hour, with a range, refreshed hourly. As far as we know it is the only public next-hour river forecast for Sri Lanka. It is a forecast, not an official warning.
GET https://waterlevels.lk/api/levels?station=hanwellaFields: level_ft (expected level), low_ft and high_ft (the range it should stay inside; null for a simple trend estimate), change_ft, direction (rising, falling, steady), crossing (for example “may reach alert level”, else null), issuedAt (the reading it starts from, ISO 8601), method (model: upstream gauges and rain; trend: recent change carried forward) experimental and rainRisk (null, or level heavy / very-heavy / possible with mm_24h when 50 mm or more of rain is forecast over the hills above the gauge in the next 24 hours; kind is forecast, measured or both, and measured names the gauge that recorded 25 mm in 1 hour or 40 mm in 3 hours; the river may then rise faster than the forecast shows). The whole nextHour is null when the gauge is not reporting or has no forecast. How well it has done: பற்றி.
Every station also has a rain block with the three rain sources kept apart: fallen_1h_mm, fallen_3h_mm and fallen_24h_mm are what the gauge’s own sensor recorded (null when it has no sensor, such as Nagalagam Street, or no reading in 2 hours; never 0 for “not measured”); satellite_6h_mm and satellite_24h_mm are the JAXA GSMaP estimate over the catchment above the gauge (an estimate that can read far higher than the gauges in the dry zone); forecast_6h_mm, forecast_24h_mm and forecast_24h_heavier_mm are the weather model’s rain over that catchment (the heavier one is the wetter ensemble scenario). The _word fields use one set of bands: for 24 hours light under 10 mm, moderate 10 to 50, heavy 50 to 100, very heavy 100 or more; for 1 hour heavy from 10 mm and very heavy from 25 mm. sources lists what was available.
Scored automatically from our prediction log every few hours: each forecast is checked against the gauge reading closest to its target time. As of 2026-10-26, over the last 30 days. Misses are in feet; “no change” means saying the level stays where it is. Further ahead is much less certain.
| Ahead | Checks | Average miss | “No change” miss | Inside range | Range width | Direction right |
|---|---|---|---|---|---|---|
| 1 h | 786 | 0.19 ft | 0.26 ft | 83% | 0.64 ft | 58% (always “steady”: 21%) |
| 3 h | 761 | 0.43 ft | 0.55 ft | 83% | 1.36 ft | 49% (always “steady”: 8%) |
| 6 h | 668 | 0.73 ft | 0.78 ft | 83% | 2.50 ft | 46% (always “steady”: 4%) |
| 12 h | 546 | 1.08 ft | 0.84 ft | 92% | 4.45 ft | 40% (always “steady”: 4%) |
| 24 h | 517 | 1.48 ft | 1.22 ft | 91% | 6.97 ft | 41% (always “steady”: 3%) |
The gauge-only model (next hour, 3 h, 6 h) has run since 2026-10-24: 297 next-hour checks, average miss 0.31 ft against 0.47 ft for "no change". The raw file is https://raw.githubusercontent.com/shakee93/sl-water-levels/data/accuracy/latest.json (per gauge too).
Storage and spill or release for about 170 reservoirs, with the day of the reading and which agency reported it. These sources update daily.
GET https://waterlevels.lk/api/reservoirsGET https://waterlevels.lk/api/reservoirs?status=spillingCanal levels for Colombo (metres above sea level, every 15 minutes), a plain state per gauge (normal, rising, higher than usual, not reporting), the last 24 hours, the sea level at the Kelani mouth and the predicted tide for the next 48 hours. Data © CUrW / SLLDC (pub.curwsl.org), shown with attribution: please credit them if you use it. It is context, not a flood warning.
GET https://waterlevels.lk/api/canalsGET https://waterlevels.lk/api/canals?group=KolonnawaAtom feed with one entry each time a gauge reaches alert level or above, or a reservoir starts releasing water.
https://waterlevels.lk/feed.xmlAn MCP server (Streamable HTTP) lets an assistant look up stations, read a gauge, walk a river from upstream to downstream and fetch the current official warnings. Tools: get_next_hour_forecast, list_basins, list_stations, get_station_readings, get_basin_snapshot, get_official_warnings, get_reservoir_releases, get_spill_watch. The station and river tools include the next-hour forecast.
https://waterlevels.lk/mcpA plain-text summary written for language models is at /llms.txt, with every gauge, reservoir and town in /llms-full.txt.
Past gauge readings and reservoir snapshots are saved to the data branch on GitHub as newline-delimited JSON. The code is open: github.com/shakee93/sl-water-levels.
Please link the specific page you used and name the source: “Sri Lanka Water Levels (Shakeeb Sadikeen), data from the Department of Irrigation, Sri Lanka”. Quote the time of the reading, not the time you fetched it.
This is an independent project, not an official warning service. In an emergency call 117 and follow the Disaster Management Centre. How the numbers are made and their limits: பற்றி.