The site of the Passy reservoirs, located at 26 rue Copernic (16th arrondissement), is as unusual as it is remarkable. An integral part of the non-potable water network owned by the City of Paris, two of the four basins are no longer in use. The first one, the Villejust reservoir, is on an easement of approximately 3,000 m2, formed by two superimposed compartments and covered by a grassy esplanade. The load-bearing structure divided into vaulted compartments contains approximately 17,000 m3 with ceiling heights reaching up to 6 meters. The second reservoir called the “fire reserve” is a single-level basin of 1,000 m2 with a volume of approximately 3,900 m3.