The Acheneau

  • L' Acheneau
  • L'Acheneau en kayak


The Acheneau flows peacefully between Lake Grandlieu and the Buzay canal. It is one of the only rivers in France to flow in both directions: its gradient is so slight (40 cm from end to end) that its course can reverse when the tides are high enough to affect the level of the Loire.
Who is the canal?
Located near the Lac de Grandlieu, the canal formerly known as "la Chenau", which means "the channel", was built to facilitate the flow of winter water from the lake to the Loire and then to the sea. Lake Grandlieu covers an area of around 35 km² in winter, and is fed by two rivers: the Boulogne to the south-east and the Ognon to the east. To the west, the lake follows a stream called the Itta and flows into the Tenu at Port-Saint-Père.
In the 18th century, steps were taken to channel the water around Lac de Grandlieu to reduce flooding.
The 19th century saw the construction of the Basse-Loire maritime canal, now known as the de la Martinière canal. The Tenu, now navigable, lost all its commercial dynamism.
Today, the Acheneau is the part of the river that flows from Lac de Grandlieu, through the communes of Port-Saint-Père and Cheix-en-Retz, to join the Loire via the Buzay canal at Rouans.

A little history :
Port-Saint-Père grew up on the banks of the Acheneau. This river, the main communication route, has played a key role in the development of the town. In the Middle Ages, the river was first crossed by a wooden footbridge. A toll ferry was later introduced. Guided by cables, residents were able to cross the Acheneau using the ferry. These crossings were dangerous for users. Many died during major floods. A drawbridge project was proposed in the 16th century. This never came to fruition. In the 18th century, the first bridge was built to cross the Acheneau safely. A storm destroyed it. The ferry was then re-established. It was 12.97 metres long and 3.41 metres wide. Tolls were set by the prison authorities. Aristide Locquet de Grandville, then mayor of Port-Saint-Père, proposed the construction of a stone bridge in 1828. Work did not begin until 1830. Tolls were still in force at the time. The Conseil Général bought the bridge back on 13 November 1879. Crossing the Acheneau became free a few days later.

5 good reasons to discover the Acheneau :
- Situated in the heart of a protected wetland area, the banks of the Acheneau and the river offer freshness and rejuvenation for most of the year!
- Come and discover the river with Escapade Nature. Starting out from the port of La Morinière in Port-Saint-Père, there's a lovely walk for you to enjoy; in a kayak, pedalo, paddle or even an electric boat, the choice is yours!
- You can also take your own paddle or kayak from the village of Cheix-en-Retz.
- Discover the pretty little port of La Morinière in Port-Saint-Père, an ideal place to take a stroll and visit the local heritage and the town of Port-Saint-Père, just a 5-minute walk from the village.
- You can also spend a few days around the Acheneau, and discover the surrounding area of Port-Saint-Père, by staying at the Nuit de Retz hotel, or at the La Morinière municipal campsite.

Would you rather walk or cycle?
Make the most of a fine day and set off to discover this waterway by following :
- from Port-Saint-Père: the red sands trail (walking trail), or the Grand Chemin trail (walking and cycling trail),
- From Cheix-en-Retz: the Pierre Tremblante walking trail.

To extend your stay in the commune, don't forget to visit France's largest safari park: Planète Sauvage!
    • River
    • Shaded area



L' Acheneau
GPS coordinates
Latitude : 47.13571
Longitude : -1.74370
  • Distance from the center (church ) :
    • 30 km. from the center of Pornic
    • 39 km. from the center of Préfailles
    • 36 km. from the center of Tharon-Plage
    • 26 km. from the center of La Bernerie
    • 25 km. from the center of Les Moutiers
    • 18 km. from the center of Arthon
    • 22 km du centre de Bourgneuf
Contact details
The Acheneau