The Pegelturm is the small round tower on Cologne's Rhine promenade that shows the river's water level on a dial like a clock. It stands on the Frankenwerft in the old town, and for Cologne it is more than a curiosity: when its hands climb, the city prepares its flood walls.
The Pegelturm at a glance
- Where: on the Frankenwerft, the Rhine promenade of the Altstadt, near the Deutz Bridge, at river kilometre 688.
- Built: 1951.
- What it is today: Cologne's official Rhine gauge, a working measuring station and a familiar meeting point.
- How to read it: the small hand shows metres and the large hand decimetres.
- Time needed: 5–10 minutes, longer if you walk the promenade.
A gauge the whole city watches
Cologne lives with the Rhine, and its water level matters to shipping, to the riverside old town and to everyone living near the banks. The gauge in its white round tower measures the level mechanically, and the readings are passed to the city's flood protection centre. Because the dial is shaped like a clock, anyone walking past can read it at a glance, and the level is one of the first things local news reports when the river rises.
The numbers on the dial have practical meaning. At around 6.2 metres, ships may only travel slowly and in the middle of the river; at 8.3 metres shipping stops, because boats can no longer pass safely under the bridges. At about 7 metres the water reaches the old town promenade and flood gates are closed, and from about 9 metres mobile flood walls must be in place in the Altstadt. Most of the city is protected up to 11.3 metres, a level expected roughly once a century.
What to look for
- The clock-like dial: read the metres on the small hand and the decimetres on the large one, and compare with the river in front of you.
- The round white tower itself, a modest piece of 1950s engineering among the old town's gabled houses.
- The quay walls along the promenade, where mobile flood barriers are fitted when the river rises.
- The ships passing by: at high readings watch how they slow down or moor.
Floods Cologne remembers
The highest level ever recorded in Cologne was 13.55 metres in 1784, during an ice flood. In the 20th century the record was 10.69 metres at the New Year flood of 1926. Then came two floods in quick succession: 10.63 metres on Christmas Eve 1993, and 10.69 metres again in January 1995, when parts of the old town were under water and the river rose up to 21 centimetres an hour. After these floods the city extended its flood defences, including the mobile walls you can see being fitted on the promenade.
Tips for your visit
- Check the reading as you walk past, then look at the river: on a normal day the level is several metres below the promenade.
- In spring or after heavy rain in the Alps, come back on different days to watch the hands move.
- Combine the tower with a walk along the Rhine from the Deutz Bridge to the Hohenzollern Bridge.
Nearby
- Fischmarkt: the old fish market square with colourful gabled houses, a few minutes north along the river.
- Great St. Martin: the Romanesque church whose tower dominates the riverfront, just behind the Fischmarkt.
- Heumarkt: one of the largest squares of the old town, with the equestrian statue of King Frederick William III, about five minutes inland.
- Deutz Bridge: cross for the view back over the old town, the cathedral and the Rhine promenade.
See Cologne with World City Trail
Our Cologne scavenger hunt turns the old town into a game you play on your phone. The route links 10 stops and takes around 2 hours, with about 20 minutes of walking. The Pegelturm is one of the stops, along with the Fischmarkt, Great St. Martin Church and Cologne Cathedral. You can play in English, German, French, Italian, Spanish or Dutch.
If you prefer a different format, there is also a self-guided walking tour and an outdoor escape game in Cologne.
Play the Cologne scavenger hunt →
Take the self-guided walking tour of Cologne →
Play the outdoor escape game in Cologne →
Facts checked in October 2026.