Geological situation
The Site
Lake Paladru is of glacial origin. It was dug, probably twice, at times when the Alpine glaciers extended as far as Lyon.
The Lac de Paladru site is typically pre-Alpine: wooded hills, ancient moraines, surround the lake and culminate at an altitude of 800 metres. Fields and pastures alternate with forests dominated by chestnut, oak and beech. Valleys, or "combes", descend from the ridges towards the lake and bring it the waters of the catchment area. In the background, combes and valleys open glimpses of the Mont du Chat, in Savoie, of the Dauphinois peaks of Chartreuse and Vercors, but also of the Belledone massif and, on a clear day, of Mont Blanc.
Features
Lake Paladru is located at an altitude of 492.40 meters NGF. It extends over the municipalities of Paladru, Montferrat. Bilieu. Charavines and Le Pin.
Its length is 5300m, its average width about 800 meters (1 km at the widest) and the depth is on average 25m and 36m maximum. Its area is 392 hectares, which makes it the fifth natural lake in France after Lake Geneva, Lake Bourget, Lake Annecy and Lake Aiguebelette.
It is fed mainly by precipitation (rain - snow).
Its outlet in Charavines is the Fure river which flows into the Isère.
A system of valves makes it possible to regulate the flow of water at the outlet of the lake according to the needs of the factories established on the course of the Fure. In the second half of the 19th century, this river supplied paper mills, steel mills, edge mills, weaving, etc....
The total capacity of the lake is 97 million m3. The complete renewal time of the lake water is estimated at 3.6 years.
The level of the lake varies. The amplitude of the variations can reach 2.50 m, which is not without consequences on the flora, the fauna and the riparian developments.
Towards Charavines:
- Trou du commissaire: steeply close to the Bois d'Amour. This is the place where a police commissioner from Voiron liked to fish
To Montferrat:
- La Véronnière: place loved by verons. The veron is a white roach.
- Ile Loyasse: island drowned under water
- Well Jayet, between the port of Paladru and the Grands Roseaux
At the entrance to Paladru:
- Well Lanfournet: place of the legend of the White Lady
At Pine:
- The submerged city of Ars, towards the beach