Low, Medium, High, Exceptional: How Pakistan’s Flood Warnings Work

Every monsoon, the same sentence appears across Pakistani media: the Chenab is at medium flood level, the Ravi at low. Millions of people read it, and very few know what it means — whether it is a reason to move livestock, move family, or ignore it entirely.

The confusion is not the reader’s fault. The categories are real, official and precise, but they are defined per station rather than per river, and that single fact undoes most intuitive readings of a flood bulletin.

Who issues the warning

Flood forecasting in Pakistan sits with the Flood Forecasting Division of the Pakistan Meteorological Department, based in Lahore. The FFD issues bulletins and advisories; the National Disaster Management Authority and the provincial PDMAs act on them; the irrigation departments and WAPDA operate the barrages and reservoirs.

The FFD bulletin is the primary document. Everything you read in a news report is a summary of it, usually a partial one.

The five levels

At each gauging station, flow is classified into one of five bands: Low Flood, Medium Flood, High Flood, Very High Flood and Exceptionally High Flood.

The critical point is that the cusec figure behind each band is specific to that station. Kalabagh’s medium flood level is 375,000 cusecs; a reading of 372,700 there is medium flood, 2,300 cusecs short of the next band. At Shahdara on the Ravi, a flow one-fifth that size is a serious event. There is no national number. Asking what counts as high flood in Pakistan has no answer; asking what counts as high flood at Marala does.

Bulletins also carry a trend marker — R for rising, F for falling — and it deserves as much attention as the level. A station at medium flood and rising is a more urgent situation than one at high flood and falling.

The rainfall scale is separate

The same bulletins classify rainfall on two independent scales, which are frequently mixed up with the flood levels.

Rainfall intensity

Light rainfall is 10mm or less in 24 hours; moderate is 10.1-30mm; heavy is 30.1-70mm; very heavy is 70.1-150mm; and extremely heavy is above 150mm.

Spatial coverage

Isolated means 20-30 per cent of an area, scattered means 31-50 per cent, fairly widespread means 51-75 per cent, and widespread means 76-100 per cent.

So a forecast of widespread rain with isolated very heavy falls describes rain across most of a region with intense bursts in a fifth to a third of it. That is a specific statement, not a vague one.

Why the main river can be calm while your street floods

This is where official terminology most often fails readers, and the clearest illustration came in late July 2026.

The Ravi at Shahdara in Lahore was carrying 22,000 cusecs. Downstream at Balloki, the flow was 87,000. Water normally loses volume as it moves downstream through diversion and absorption; here it had gained 65,000 cusecs. The additional water was not river flow at all. It had entered through drains and direct rainfall between the two stations.

Around 400 square kilometres went under water across Sheikhupura, Muridke, Gujranwala, Narowal, Sambrial and Pasrur, while the main-stem gauge readings on the Ravi remained comparatively modest.

The FFD has warned of this pattern explicitly. In mid-August 2026 it forecast that major rim-gauging stations on the Chenab and Ravi would stay at low flood levels while adjoining nullahs could reach medium and, with a significant rise in tributary flows, high flood levels — with urban flooding expected in Rawalpindi, Lahore, Gujranwala, Sialkot, Faisalabad and Gujrat.

For anyone living near a nullah, the main river reading is close to irrelevant. Rawalpindi’s exposure runs through Nullah Leh, not the Jhelum.

What exceptional actually looks like

The top band is rare enough that most people have never seen it applied. In August 2025 the Chenab at Qadirabad and Khanki, the Ravi at Jassar and the Sutlej at Ganda Singh Wala were all simultaneously in exceptionally high flood. Outflows at Khanki and Qadirabad exceeded one million cusecs and were still rising. Jassar had been declared exceptionally high at two in the morning.

The human scale of these events is the reason the terminology is worth learning. The 2022 floods killed more than 1,700 people. The 2025 season claimed around 800.

How to check conditions where you are

The FFD bulletin page carries live station-by-station levels, trends and 24–36 hour forecasts.

Identify the gauging station nearest you, not the river. Marala, Khanki, Qadirabad, Jassar, Shahdara, Balloki, Ganda Singh Wala, Sulemanki, Kalabagh, Chashma, Taunsa, Guddu, Sukkur and Kotri are the ones that appear most often.

If you live near a nullah or storm drain, read the nullah forecast, which is issued separately from the main-stem forecast.

NDMA and your provincial PDMA issue the evacuation advisories; the FFD issues the hydrology.

Watch reservoir levels too. Tarbela at maximum conservation level means incoming water passes straight through rather than being absorbed.

The practical summary: a rising medium-flood reading at your nearest station, combined with heavy rain forecast over the upstream catchment, is the combination that precedes trouble — and it usually appears in the bulletin a day or two before it appears in the news.