World Church · October 26, 2026
Also published in Norsk
Secret water network beneath Vatican revealed during tourist visits
During vacations visitors may have toured the Vatican and its famous gardens. Under one hundred fountains and ornaments lies an invisible city with its hydraulic networks, cisterns, irrigation installations and pumping stations. Papes, cardinals, prelates, visitors and tourists like to rest on the edge of the many fountains that beautify the Vatican and its gardens. Few know of the complex water distribution network beneath their feet, composed of kilometers of pipes requiring constant monitoring and planned interventions. Beyond providing drinking water and amenity, this network also serves fire protection. The Vatican City State invites discovery of this vast network.
"Water management in the State translates daily into the design, maintenance and rigorous control of strategic infrastructures and installations," says engineer Salvatore Farina, director of infrastructures and services of the Governatorate. The proper functioning of the water network contributes to preserving a unique historical, artistic and botanical heritage in the world.
A marble plan, memory of the underground city
In the Vatican Hydraulic Station, an underground technical space invisible to visitors preserves a large marble plan realized in 1933. The title of this plaque is in itself a whole program: "Vatican City State, General Plan, Water Distribution." This map reveals the potable water supply network, for fire protection, fountain supply and irrigation of lawns and forests. Made of Carrara marble, it represents the hydraulic network of the Vatican arranged between 1932 and 1933, and inaugurated by Pius XI on 12 May 1933.
Hydraulic pumps in cast iron rest on precious marble bases such as Verde Alpi, Rosso Antico d'Italia and Pietra di Trani, also used for the covering of the old control panel. This choice testifies how an essentially technical structure could be designed paying particular attention to architectural quality.
Networks, sources and strategic storage
Not having sufficient internal autonomous water reserves to cover all its needs, the Vatican City State resorts to a diverse supply system. For human consumption, feeding and domestic uses, water comes from the network managed by the city of Rome and the Latium region, fed mainly by the Peschiera-Capore aqueduct.
For technical uses, irrigation of the Gardens and supply of the hundred historic fountains, the system drew until 2017 from the old aqueduct "Acqua Paola." Constructed by Emperor Trajan in the first century and renovated by Pope Paul V in the seventeenth century, this work conveyed water from Lake Bracciano located about sixty kilometers north of the Eternal City. But following the excessive drop in the lake level, the responsible authorities prohibited using its waters to supply the Vatican.
To ensure regular supply, storage systems play a fundamental role. The large Acqua Paola reservoir, located near Saint John's Tower, built in 1930, with a capacity of approximately 2000 cubic meters is destined for irrigation and fire fighting. A drinking water cistern of 4000 cubic meters is situated under the Léon XIII building, in the historic Radio Vatican sector.
The fire fighting network, installed in 1934, extends about thirty kilometers and includes more than five hundred hydrants. It is fed by the Acqua Paola reservoir with a flow reaching 45 liters per second.
Water management today calls for much more advanced technologies with computerized systems.
One of the major challenges concerns the Vatican Gardens, which occupy more than half the area of the State. The modernization of the irrigation system, dating from 1932-1933, has allowed installation of more resistant pipes, automatic systems and a precision distribution device. For about twelve kilometers of boxwood and privet hedges, drip irrigation piloted remotely via a server has allowed saving approximately 60 percent of water.
Watering of green spaces and street cleaning also draws water from several wells located inside the Vatican walls.
Fountains constitute the most visible part of the hydraulic infrastructure. The most important and function in a closed circuit, in which water is filtered, treated against limescale, then remediated in circulation by electric pumps.
In July 2017, during the severe drought that struck Rome and Latium, the Governatorate ordered the stop of fountains, including those of the Vatican Gardens and Saint Peter's Square: a choice that frustrated many visitors.
A network in renewal: digitalization and preventive maintenance
Progressive modernization of the Vatican's hydraulic infrastructures is a constant issue. In 2023, the hydraulic distribution system of the Apostolic Palace, where the pope lives, underwent a complete renovation: change of pipes, installation of sensors to record flow and detect leaks, pressurization group, remote controls etc. "A well-designed work requires attentive and constant maintenance over time," says engineer Carlo D'Alessandris.
From technique to a culture of care