Paladru Lake is of glacial origin. It was dug, probably twice, at times when the alpine glaciers stretched to Lyon.
The site of Lake Paladru is typically pre-alpine: wooded hills, ancient moraines, surround the lake and culminate at 800 meters above sea level. Fields and pastures alternate with forests dominated by chestnut, oak and beech. Valleys, or "combes", descend from the ridges to the lake and bring water from the watershed. In the background, valleys and valleys open glimpses on the Mont du Chat, in Savoie, on the Dauphine summits of Chartreuse and Vercors but also on the Belledone massif and, on a clear day, on that of Mont Blanc.
Lake Paladru is located at an altitude of 492.40 meters NGF. It extends over the municipalities of Paladru, Montferrat. Bilieu. Charavines and The Pine.
Its length is 5300m, its average width is 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 to Charavines is the river Fure which flows into the Isere.
A system of valves makes it possible to regulate the flow of water at the exit 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 fed paper mills, steel mills, cutlery, weaving, etc.
The total capacity of the lake is 97 million m3. The total renewal time of the lake water is estimated at 3.6 years.
The lake level varies. The amplitude of the variations can reach 2.50 m, which is not without consequences on the flora, the fauna and the riparian installations.
- Commissioner's Hole: steep near the Bois d'Amour. This is the place where fishing for a police commissioner from Voiron
- La Véronnière: a place loved by verons. The veron is a white roach.
- Loyasse Island: island drowned under water
- Jayet Well, between the port of Paladru and the Great Reeds
At the entrance to Paladru:
- Lanfournet well: place of the legend of the White Lady
At the Pine:
- The city of Ars swallowed, towards the beach