The last arch fell into disuse as this bank was silted up by the action of the Rhone washing against the Rocher des Doms and the place where the bridge touched the bank was enclosed within the city walls in the 14th century.
L'ensablement de ce rivage, par le rebondissement du Rhône sur le front du Rocher des Doms, amena la perte d'utilité du dernier arc et la mise intramuros de cette zone d'échouage (XlVe siècle).