Lacs et Marais of Saint Jean de Chevelu

Of glacial origin, these lakes were formed by the collapse of part of the Dent du Chat mountain, which occurred after the retreat of the last glaciers.

Since 1990, the lakes and wetlands have been protected by a prefectural decree.
Originally a single basin, it gradually filled in over time, giving rise to two small lakes. Today, their depth does not exceed 8 meters.

The surrounding marshland has significant heritage value.

Certain human activities that could disrupt the ecological balance are prohibited there.

The marshes are managed by the Conservatoire du Patrimoine Naturel de la Savoie (CPNS).

Since 1992, the CPNS has carried out studies, scientific monitoring, and land management in partnership with the municipality (purchases and leases), as well as brush-clearing and mowing operations.

Today, mowing is carried out annually using a tractor and specialized equipment. The blache (reed straw) is harvested, formed into round bales, and sold to interested farmers.

In 1997, the entire marsh regained a significant area of wet meadows, helping to preserve valuable plant and animal life.