The Couesnon river, near the town of Pontorson, leads directly to Mont Saint-Michel, seen in the distance.

The Couesnon river is a short (90 km long) river running from the department of Mayenne in north-western France, forming an estuary at Mont Saint-Michel. Its final stretch forms the border between the historical Duchies of Normandy and Brittany. Its historically irregular course inspired the saying "The Couesnon's madness caused Mont Saint-Michel to be in Normandy", as the Mount is just to the Norman side of the river's current mouth. Mont-Saint-Michel: Sheep graze on the reclaimed pré-salé or salt meadow (2004). ... Mayenne is a département in northwest France named after the Mayenne River. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing numerous ecological, economic, cultural, and aesthetic benefits and services. ... Mont-Saint-Michel: Sheep graze on the reclaimed pré-salé or salt meadow (2004). ... Normandy Invasion]] or Operation Overlord that began on June 6, 1944, which today is also known as D-Day. ... Traditional coat of arms This article is about the historical kingdom, duchy and French province, as well as one of the Celtic Nations . ...

Geography

The muddy edges of the Couesnon are almost like quicksand to the unwary.

The Couesnon, the Sée and the Sélune form part of the complex water system of the bay of Mont Saint-Michel. On one side, the tide brings large quantities of sediment which cause large sandbars within the river. On the other, the three watercourses drive the sediment back out to sea. The tide is the regular rising and falling of the oceans surface caused by changes in gravitational forces external to the Earth. ...

The mouth of the Couesnon, at Mont Saint-Michel.

In the 19th century, the Couesnon was turned into a canal, to reduce the erosion of its banks. In 1969, a dam was erected. These modifications, and the causeway linking Mont Saint-Michel to the mainland, have caused the buildup of mudflats. To prevent the Mont becoming too connected to the mainland, plans are in place to replace the causeway with a bridge, and to modify the dam so that the sediment can once again be driven out to sea.

During spring tides, a tidal bore — a wave caused by the incoming tide — can be seen working its way up the river. The tide is the regular rising and falling of the oceans surface caused by changes in gravitational forces external to the Earth. ... The tidal bore in Upper Cook Inlet, Alaska A tidal bore (or just bore, or eagre) is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travel up a river or narrow bay against the direction of the current. ...

The causeway connecting Mont Saint-Michel to the mainland, responsible for the massive build up of mud and sediment in the area.

External links

• The public works project
• The Couesnon on the site sandre.eaufrance.fr

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Couesnon