Water intake and discharge in Lake Annecy for an energy supply system

The project, led by IDEX ENERGIES (the project owner) and SGI (the project manager), consists of constructing a heating and cooling energy network that will utilise water from Lake Annecy. The major challenges involve reducing greenhouse gas emissions, providing more rational energy use and developing renewable resources. BONNA TP won this project in partnership with Maïa Sonnier and Maïa Fondations.

The project includes the construction of an underground pumping station protected by a sheet-pile enclosure and the construction of an intake and a discharge with diffuser in Lake Annecy. The specifications of the pipes used in the project are : HDPE water intake / DN710 mm / Length 420 m / Depth -21 m  and  HDPE discharge with diffuser / DN500 mm / Length 260 m / Depth -10 m. To ensure the stability and protection of the project’s pipes, three sections were defined : Complete backfilling (upstream section) / Partial backfilling (with concrete cushion) / Laying on the lake bottom (pipe with concrete weights).