DHM River Gauging & Flood-Watch Stations of Nepal: Explainer + Directory

A river gauging (or hydrometric) station is a fixed point on a river where the water level, and often the discharge or flow, is measured continuously. In Nepal these stations are operated by the Department of Hydrology and Meteorology (DHM), a body under the Ministry of Energy, Water Resources and Irrigation. Historically many stations were read manually with a staff gauge painted on a concrete pillar; today the flood-critical ones carry a Real-time Level Sensor (RLS) that transmits readings automatically every few minutes.

Nepal's geography makes this monitoring essential. Rivers such as the Koshi, Karnali, Narayani (Gandaki) and Bagmati drain steep Himalayan catchments where intense monsoon rain, from roughly June to September, can raise water levels by several metres within hours. Because floodwater travels downstream from the hills to the densely settled Tarai plains and on into India, an upstream gauge reading gives communities and authorities a crucial lead time of anywhere from an hour to a day.

The data these stations produce feeds three things at once: a public early-warning system, official flood bulletins issued to the Ministry of Home Affairs and district authorities, and long-term hydrological records used for bridge design, irrigation and hydropower planning. During the monsoon the gauge readings are the single most-searched piece of hydrological information in Nepal, behind queries such as 'koshi water level' and 'nepal flood warning'.

For each flood-critical station DHM defines two reference water levels, expressed as a gauge height in metres. The 'warning level' (also called the alert level) is the height at which the river is rising toward flood conditions and downstream communities should be put on alert. The 'danger level' is the higher threshold at which the river is considered likely to overtop banks, inundate settlements or threaten structures, and at which evacuation and emergency response are triggered.

These thresholds are station-specific: a danger level of, say, 10.8 m at one station has no meaning at another, because each gauge has its own local datum, channel shape and bank height. That is why DHM's River Watch table lists the current water level alongside that station's own warning and danger figures, and colour-codes each station as below warning, above warning, or above danger. Trend arrows show whether the level is rising, steady or falling.

It is important to read the levels as gauge heights, not as the depth of water over the land. A river can be several metres deep in its channel at 'normal' flow; the danger level marks the point where that channel can no longer contain the flow safely. DHM periodically revises thresholds after major floods or channel changes, so the numbers published on the live portal always take precedence over any figure quoted in a news report or a static page like this one.

The four stations below are among the most closely watched during the monsoon because they sit on Nepal's largest river systems just before those rivers reach heavily populated areas. The exact warning and danger figures are set and revised by DHM; where a widely reported value exists it is noted, but readers should always confirm the current official threshold on DHM's live River Watch portal before acting.

Chatara on the Koshi (Saptakoshi) is the primary gauge for eastern Nepal's largest river, sitting where the Sun Koshi, Arun and Tamor combine just above the Tarai and the Koshi Barrage. Because the Koshi carries an enormous catchment, a rise at Chatara is a leading indicator of flooding in Sunsari, Saptari and across the border in Bihar. Chisapani on the Karnali, in far-western Nepal, guards the country's longest river; a widely cited threshold for Chisapani is a warning level of 10 m and a danger level of 10.8 m, at which SMS alerts are sent to downstream municipalities, the Armed Police Force, the Nepal Red Cross and local communities.

Devghat on the Narayani (Gandaki) monitors the confluence area near Chitwan and Nawalparasi; a danger mark of about 7.3 m at Devghat is commonly reported, with a separate downstream gauge at the Narayani Bridge in Narayanghat carrying its own, higher alert level. Rai Goan on the Bagmati is the reference gauge for the Bagmati basin, which drains the Kathmandu Valley and then flows south through Sarlahi and Rautahat to the Indian border; it is the station most relevant to searches for a 'bagmati danger level'. DHM also maintains separate Bagmati gauges inside the valley (such as at Khokana and Gaurighat) for local Kathmandu flooding.

DHM publishes near-real-time gauge readings on its Hydrology section at dhm.gov.np/hydrology, with the flood-focused view under 'River Watch' and 'Flood Monitoring'. The table lists each station with its basin, district, latest water level in metres, the station's warning and danger levels, a trend arrow and a status colour. A companion 'Real-time Stream Flow' view plots the level over recent hours so you can see how fast a river is rising.

To check a specific river, find its station in the list — for example 'Saptakoshi at Chatara' for the Koshi, 'Karnali at Chisapani' for the Karnali, 'Narayani at Devghat' for the Gandaki system, or the Bagmati station at Rai Goan. Compare the current level against that station's danger figure and note the trend: a level below the danger mark but rising quickly can still be more urgent than a higher but falling level. During major events DHM also issues text flood bulletins and, for some basins, SMS alerts.

This amarnepal page deliberately embeds no live numbers, because gauge readings change minute by minute and any figure copied here would be stale within the hour. Treat this directory as a map of which station watches which river; for the actual current level and the official threshold, always open the DHM portal itself.

Nepal's flood season runs with the summer monsoon, broadly mid-June to late September (roughly Asar to Asoj in the Bikram Sambat calendar). During this window the flood-watch stations are monitored most intensively and DHM's Hydrology Division runs a flood forecasting service that combines ground gauge data with rainfall observations and numerical models. Some of the most damaging events on record, including widespread flooding in September 2024, saw multiple major rivers cross their danger levels simultaneously.

Forecasting extends the lead time beyond what a single gauge can give. DHM works with partners such as ICIMOD and uses tools drawing on the Global Flood Awareness System (GloFAS) and satellite-based streamflow prediction to estimate discharge days in advance for large basins like the Koshi, Karnali and Narayani. These forecasts feed 'anticipatory action' schemes, where aid and evacuation support are released before a flood peaks rather than after, using an agreed trigger such as the Chisapani warning level being forecast to breach.

Even with forecasting, the observed gauge remains the ground truth that confirms a flood is actually happening. That is why the warning and danger levels at Chatara, Chisapani, Devghat and Rai Goan stay central to Nepal's flood response, and why their live readings dominate search traffic every monsoon.

For anyone living near or downstream of these rivers, the practical routine during heavy monsoon rain is simple: check the relevant DHM station, note whether the level is above the warning or danger mark, and watch the trend. Local administrations in the Tarai typically issue their own alerts to riverside settlements once an upstream gauge crosses warning level, so combining the DHM reading with local government notices gives the fullest picture.

There are real limitations to keep in mind. Sensors can drop out during the very storms when they matter most, so a missing or frozen reading is not the same as a safe river. Flash floods in small hill catchments and landslide-dam bursts can outrun any gauge, and cross-border releases from barrages add complexity in the Tarai. Reported threshold numbers also vary between news outlets and can lag DHM's revisions, which is why this page treats the live portal as authoritative.

Finally, remember that this is a reference explainer, not an emergency service. In an active flood, follow instructions from local authorities, the District Emergency Operation Centre and the Nepal Police, and do not rely on a single gauge reading or a static web page for a life-safety decision.