Lancey sediment deposition area

Sediment deposition area in the Combe de Lancey area in Villard-Bonnot (Isère, France).


Lancey sediment deposition area (France) - Client: Municipality of Villard-Bonnot - Scale: 1:40

Lancey sediment deposition area (France) - Client:: Municipality of Villard-Bonnot | Artelia Hydraulics
Model of the Lancey sediment deposition area


During the 2005 floods, significant flooding occurred in Villard-Bonnot, in particular under the effect of intense sediment transport that must be managed more effectively.

In the context of redevelopment of the former papermill in the town of Villard-Bonnot, installation of a structure to function as a sediment deposition area is being considered.

Purpose of the physical model

1. Dimensional design of the deposition area outflow structure:

  • Capture of sediments during large floods, and full opening of the gates during regular floods
  • Capture of floating debris

2. Checking of the effectiveness of the deposition area (storage capacity of 20,000 m3).

Description of the physical model

  • Simulation of a 100-year flood, such as the 2005 event
  • Validation and optimisation of the development
  • Test in case the deposition area is already saturated
  • Continuous measurement of sediemnt inflows and outflows; monitoring of the topography of deposits at the end of the test
  • Addition of floating wooden debris
  • Grain size sensitivity test

flow rates

Grain size distribution

Dimensions of deposition area

Q100 liquids
= 35 m3/s

100-year volume:
20,000 m3

D16 = 20 mm

D50 = 47 mm

D84 = 111 mm

150 m*150 m