Five turrets stand on a rectangular underground water reservoir. The four small ones, on the four slopes guarantee the ventilation of the tank. The larger one, built on one of its sides, provides access to the machines and inside the tank.

Their location in the landscape, on a hill, makes it possible to observe the whole from several points of view, always distant. That is why we have interest to accentuate artificially all the elements of the whole. Portals, whose official role has been amplified, take up this double aim, since they have been clearly dissociated from all resistance work, while their structural appearance is increased.