Every day, Paris consumes about 170,000 m³ of non-potable water through a system from the period of Haussmann’s city improvements, mid-19th century.
This network has a dual system of pipes: one for potable and one for non-potable water.
Are you curious about numbers?
Count on 1,700 km of underground pipes for non-potable water, 2,500 cisterns that automatically and periodically flush the sewer and 12,000 so-called bouches de lavage.
Look at the ground more often and it strikes you: running water along Parisian curbs. With a wrench into the cover of the bouche de lavage, the water tap is opened periodically between 6 am and 4 pm. Bouches are at a higher point. Using a rolled-up piece of fabric or carpet and, more recently, pieces of plastic, the water stream is led to a lower point. There, it will disappear through the wide opening of a drain in the direction of the sewer.
Streets are washed clean, litter is taken along and the water provides cooling. Where the opening is likely to clog, municipal cleaners come into action, who also sweep sidewalks, handle the water spray and shut off the water taps.
Paris companies make use of it. Parks and public gardens are sprayed with it. The water in Bois de Vincennes and Boulogne’s rivers and lakes is refreshed with it.
The factories Austerlitz ( 13th), Auteuil (16th) and Villette in the 18th arrondissement ensure the production. They pump the water from the Seine and Canal de l’Ourcq and process it.
Subsequently, the water is stored in tanks scattered around the city. Those reservoirs, accounting for 180,000 m³, can be found in Montmartre, Belleville, Grenelle and Passy among others.
In 2012, the city of Paris approved the decision to preserve the heritage of Haussmann and civil engineer Belgrand. With an extensive improvement and maintenance program, it should be able to keep up for a few more decades.