While most will be aware of the heatwave in Europe because of the news coverage of wildfires in France and Spain, less has been reported about the effect on river levels.

But the River Rhine has touched the lowest levels ever recorded in parts of the Netherlands and Germany, including at Cologne.

It joins parts of the Danube in achieving this “lowest ever” record.

The Low Water Information System in Germany has reported “extremely low” levels at nearly 80 per cent of its recording stations during recent tests.

Reader Leonie Moore and partner Steve Foreman have been feeling the effects over the past two weeks, on a Viking cruise from Vienna to Bucharest on the Danube.

Leonie writes that the Danube (due to climate change, according to the staff) has water levels at all-time low: “I understand it is at 22cm in some places.”

She explains: “We have had to change ships to avoid the worst sections and had long bus extension (six hours) from Hungary to Croatia to get around one area of the river which was impassable.

“Our planned port stops have changed to avoid the worst areas.

“For example, we were berthed 50km from Bucharest rather than in the city itself.”

But Leonie says the Viking staff have done well, keeping guests informed of all the issues and making lots of changes to the itinerary so they don’t miss out on most of the excursions.

She adds: “Overall, the tour has been great, but don’t expect to ‘unpack once’ because we have done it twice.

“We have ended the river component a day early, in Vidin, Bulgaria, instead of Constanta in Romania, leading to a six-hour bus ride to Bucharest, Romania, and spending an extra night in a hotel.

“We have spent more time on a bus than anticipated — and I chose this trip to avoid buses!”

Leonie hopes her experience is of interest to readers planning on doing a European river cruise soon.