Transporting freight on inland waterways is far more environmentally friendly than by road. But low rainfall and high temperatures have dramatically reduced water levels in France, limiting transport on canals around the Rhine river in particular.
France transported 52 million tonnes of cargo on its waterways in 2021 – the equivalent of more than 2,625,000 trucks on the road.
And several million tonnes of coal and petrol products sailed down the 184 kms of the Rhine river which runs along the Franco-German border.
But while inland waterway transport can help reduce global warming by emitting fewer carbon emissions, it is also vulnerable to climate change because river navigation needs, obviously, water.
And this year water is lacking. The upper and lower Rhine departments, like the vast majority of France's departments, are on drought alert following prolonged low rainfall and high temperatures.
The river relies on melting snow from the Alps during the spring, but since April there's been very little rain.
The Rhine "is flowing at half the average rate for this time of year", said Vincent Steimer, director of the territorial units of state-funded Waterways France (VNF) in Strasbourg.
Water reserves are down
Only a small fraction of the 1,300-km Rhine runs through France, and most of it is canalised.
VNF, which manages 6,700kms of rivers and canals in France, says freight transport on the Rhine has not been hugely impacted by the lower water levels, partly thanks to a system of dams.
But canals, which rely largely on supplies from reservoirs, are more affected.
On 1 July reservoirs had "60 percent of their capacity compared to 72 percent on 1 June this year," says Cécile Aveard, head of the Rhone-Saone branch of Waterways France. A decade ago they were 80 percent full at this time of year.
"It's worrying," she told RFI. "It shows that it's rained a lot less this year, and it's very hot so there's natural evaporation leading to diminished water reserves."
Reservoirs act as a kind of "natural watering of all the territory", she explains, supplying drinking water and irrigation for agriculture. In times of drought, keeping canals filled up to allow navigation is not VSF's main priority.
French authorities fix a minimum level for water reserves, partly to preserve aquatic life. Below that point, water can no longer be taken from rivers or reservoirs to feed canals and navigation can be stopped.
On 16 July, navigation was halted on a section of the Burgundy Canal between Tonnerre and Migennes.
Lighter cargo
Faced with the drop in water level, vessels are having to adapt.
"To navigate in these more shallow waters, they need to carry much lighter loads," says Aveard.
Many of the boats passing through the Gambsheim lock on the French side of the border with Germany are only a quarter full.
"The boat currently in the lock has a capacity of 4,000 tonnes and a load of 950 tonnes," lock-keeper Michel told France Bleu Alsace.
La sécheresse a aussi des impacts sur le débit du Rhin… Il a diminué de moitié depuis une dizaine de jours. Conséquence : les transporteurs de marchandises, qui passent ici par l’écluse de Gambsheim, ne peuvent emporter qu’un tiers de leur cargaison, pour ne pas racler le fond ! pic.twitter.com/8JfBXIUbup
— France Bleu Alsace (@bleualsace) July 25, 2022
"Companies are forced to develop slightly different strategies," said Céline Ohresser, from the development department of VNF Strasbourg.
"We are in the summer period so they can regulate [their stocks] a little – import or export things later."
Alternative routes
Transporters can either pay for extra boats to shift their cargo, or switch to trucks or trains.
"Customers tell me that if the water remains at this level, they will transfer the goods by other means of transport," Dutchman René Goedgezelschap said as he was transporting reduced quantities of cellulose on his 110-metre long barge.
VNF fears industries and businesses could be heavily impacted if the water levels don't rise.
After a particularly dry period in 2018, VNF entered into a partnership with French railway operator SNCF “to support companies that want to switch to rail”, Ohresser said.
Highway to climate hell
Returning to the highway is not a solution VNF favours.
"The question is to avoid as much as possible a massive transfer to the road," Ohresser continues. "That will only amplify the [climate] phenomenon.
“For the largest ships on the Rhine, it would take an average of more than 250 lorries to transport the same quantity of goods.”
That's also a hard hit with fuel prices at record highs.
Tourism
The decision to halt navigation on part of the old Burgundy Canal will have minimal impact on freight since its narrowness limits the transport of cargo.
But it's very popular with tourists on pleasure boats.
Whether for cargo or tourism, Aveard insists waterway transport is the future.
"Navigating on waterways, on such a large scale, emits four to five times less carbon per tonne of cargo compared to the road. It's a real advantage for France."