Nature and mankind industry have given Moissac two waterways which add to the prestige of Moissac. The Tarn river develops out before joining with the Garonne river and the "canal des deux mers" with its long, wide perspective adorns the town : cobbled streets, boulevards, squares.

Here, the Tarn river has always been generous. The beautiful mouth where it meets the Garonne river a few kilometres away has become an artificial lake. Moissac inhabitants have always relied on those rivers for their livelihood. As a matter of fact, corn was brought down from the Quercy hillocks, its flour was milled at Moissac "bladier" large mill before being shipped through the Canal "floating road" to Guadeloupe (then a French colony in the Caribbean islands) where it was deemed of excellent quality.

MOISSAC prospered and developed in the 17th and 18th centuries thanks to corn. The vestiges of a harbour, millers' and captains' private mansions are still marks of that era. Besides the traditionnal "Sailors day" has taken place for centuries on the weekend and Monday of Pentecost, along the splendid Moulin promenade.

Water also means the superb, wide Tarn lake where numerous sport, tourist activities are available (fishing, sailing, water-skiing...).
In the 1990's, the lake was renovated, the banks were converted, lighted.

When you drive past Moissac two islands stand out the Tarn river:
- Bidounet island which houses a three-star rated, quiet, attractive campsite.
- Beaucaire island has been turned into a reservation, recreating typical river landscapes
.
The Bidounet mill stands between the islands, it is an information office welcoming visitors, was the birthplace of Firmin Bouisset (1859-1925).

What else can be said about the river front with runs past long, shaded walks, about the Cacor bridge, a superb work of art on which the canal flows, about the Napolean bridge: a witness to the arrival of two 19th century's Napoleonic emperors.

But, the Tarn in Moissac also reminds of the cruel flooding on the 3rd and 4th of March 1930. The fronts of rebuilt houses are nowadays' exemples of the 30's style.

Water also means the canal between the two Seas(the canal lateral to the Garonne river) which flows from the Canal du Midi, ranked among World Heritage by UNESCO.

Marines barges no longer sail on the canal and through the four revolving bridges, one of which still exists, but pleasure boats can still sail on it and find a comfortable stop-over.