35 kilometres north west away from Grenoble is the pond of the Grand Lemps, which is well known by the naturalists due to its floristic and faunistic exuberance.

It is the only place in Isere where you can observe the alpine newt.

During its reproduction cycle, a large number of amphibians were run over by cars, which was obvisouly dangerous for the amphibians but also for the drivers, as the road was slippery.

  First of all nets have been set up on 1,4 km during the migration cycle (Late february until the beginning of march) by the League for the protection of birds. Thus every 15meters a bucket was used to retrieve the amphibians and each morning a voluntar would count them. This system permits to avoid the squashing of the amphibians and to get to know them better. The 3rd year fast 10.000 amphibians were counted!

Following this study, 13 double underpasses were built: Hump of 35x40cm in the shape of a "U" with a lid on the top and argillaceous soil at the bottom. To force them to use thoses passes a main sewer has been built too. When the amphibians want to go from one side to the other, they fall in the main sewer and then have to follow it to go on the other side. The same system has been used for the return.

   In 2007 was built the fauna path of Bonne famille.

Each year, during the reproduction season (spring) near Isle Crémieu, thousands of amphibians cross the road 124 to go to the pond located on the other side of the road. Those amphibians are protected by the french and european laws. In 2001 the LPO has counted more than 3463 common toads, 14 red frogs, 10 agile frogs, 4 green frogs and 1 palmate newt.

AThe presence of those amphibians on the road is obviously dangerous for the frogs themselves but also for the drivers, as the road is slippery and a lot of other predators is coming.

4 underpaths will be created under the road along 400 meters.

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