There are important waterways in Moissac: the Tarn flows through the centre of town, as does the Canal de Garonne (formerly Canal latéral à la Garonne), the extension of the Canal du Midi from Toulouse to Bordeaux.
Ada sejumlah jalur air yang penting di Moissac: Sungai Tarn mengalir melalui pusa kota, begitupun Canal de Garonne (dahulu Canal latéral à la Garonne),perpanjangan Canal du Midi dari Toulouse ke Bordeaux.