Brondeloire stormwater storage basin

Verification of the complex hydraulic operation of the storage tank feeders

Client: Lille Métropole - Model scale: 1:16.48

Context

During the recurring and important rainy events, the inhabitants of Roubaix, Trichon district, Wasquehal and Tourcoing, Blanc Seau district are flooded due to sewer overflows. The MEL has therefore launched the project to build the storm basin, in the Brondeloire sector. This basin will have a storage capacity of 23,500 m3 and will be supplied at a maximum discharge of 17.3 m3/s via a storm weir, a headrace and a vertical shaft. Considering the strategic importance of this structure and the high discharge, the client, Lille–Métropole, wanted the dimensional design to be validated by a physical model. Artelia was commissioned to perform the study.

Aims of the physical scale model

• Characterise the flows along the different structures in the current configuration of the project
• Optimise the project with regard to the structures on which design criteria may not be met or malfunctions are observed.

Description of the physical scale model

• The Trichon sewer is considered over a length of approximately 110 m
• The four junction chambers and the connections between chambers,
• The storm weir,
• The inlet chamber,
• The headrace,
• The screening pit,
• The distribution structure with scum baffles, overflow weirs and grids
• The frontal screen rake channel with the grid
• The stepped vortex drop shaft.