The Tersac bridge, which crosses the Canal Latéral à la Garonne at Meilhan-sur-Garonne downstream of Marmande, is in danger of collapsing following major damage caused by a falling tree during a storm in February 2024. This situation is paralyzing not only navigation, but also land passage for cars, cyclists and pedestrians. Local authorities Val de Garonne and Voies Navigables de France (VNF) are faced with a complex dilemma.
Irreversible damage
" It's an aging bridge. The tree came down on an arch and twisted the deck "explains VNF's Michel Lapouyalere. The incident led to a unanimous conclusion: the need to demolish the bridge. Initial analyses confirmed that the structure could not be saved, heralding a deconstruction and reconstruction project.
2 options under consideration
Two scenarios are possible. The first is to temporarily consolidate the bridge to enable the canal to be reopened quickly, followed by demolition during a period of reduced river activity. Although this is a quick solution, it does not appear to have been chosen at present. The second option is to demolish the bridge to avoid any further risk. This seems the most likely solution, although it would prolong the closure of the canal for a long time.
Technical complexity and coordination
Demolition must be carried out with care. " The canal must be drained and kept dry to avoid damaging the silt that seals it with the debris from the bridge "says Michel Lapouyalere. This complex operation requires coordination between various players, including utilities and insurance companies, to determine responsibility and plan the work. Water and electricity networks also cross the bridge.
A headache for decision-makers
The Tersac bridge is a headache for authorities and engineers alike. The decision to demolish and rebuild this infrastructure requires careful consideration of the short- and long-term implications for the region. The stakes are high, not only for the safety of users, but also for the impact on local tourism.
Boaters taken hostage
If an exemption has been proposed for a sailboat to pass under the bridge in March this solution will not be repeated. For the time being, navigation is irremediably closed between locks 46 and 47. A terse press release from VNF announces: " Blocked boats are invited to choose an alternative route or to consider a transfer by road to cross reach 47 of the Canal Latéral à la Garonne, under the strict responsibility of the boat owners. "It's hard to imagine an itinerary through Gibraltar when you're sailing on an approved river boat... As for road transport, it's bound to be costly for the owners.
Let's hope that the work doesn't take too long, that it starts quickly and doesn't hold up river users for too long. It seems, however, that the 2024 summer season may well be in jeopardy...
