Fountain - How Fountains Work

How Fountains Work

From Roman times until the 20th century, fountains operated by gravity, requiring a source of water higher than the fountain itself to make the water flow. The greater the difference between the elevation of the source of water and the fountain, the higher the water would go upwards from the fountain.

In Roman cities, water for fountains came from lakes and rivers and springs in the hills, brought into city in aqueducts and then distributed to fountains through a system of lead pipes.

From the Middle Ages onwards, fountains in villages or towns were connected to springs, or to channels which brought water from lakes or rivers. In Provence, a typical village fountain consisted of a pipe or underground duct from a spring at a higher elevation than the fountain. The water from the spring flowed down to the fountain, then up a tube into a bulb-shaped stone vessel, like a large vase with a cover on top. The inside of the vase, called the bassin de répartition, was filled with water up to a level just above the mouths of the canons, or spouts, which slanted downwards. The water poured down through the canons, creating a siphon, so that the fountain ran continually.

In cities and towns, residents filled vessels or jars of water jets from the canons of the fountain or paid a water porter to bring the water to their home. Horses and domestic animals could drink the water in the basin below the fountain. The water not used often flowed into a separate series of basins, a lavoir, used for washing and rinsing clothes. After being used for washing, the same water then ran through a channel to the town's kitchen garden. In Provence, since clothes were washed with ashes, the water that flowed into the garden contained potassium, and was valuable as fertilizer.

The most famous fountains of the Renaissance, at the Villa d'Este in Tivoli, were located on a steep slope near a river; the builders ran a channel from the river to a large fountain at top of the garden, which then fed other fountains and basins on the levels below. The fountains of Rome, built from the Renaissance through the 18th century, took their water from rebuilt Roman acqueducts which brought water from lakes and rivers at a higher elevation than the fountains. Those fountains with a high source of water, such as the Triton Fountain, could shoot water 16 feet (4.9 m) in air. Fountains with a lower source, such as the Trevi Fountain, could only have water pour downwards. The architect of the Trevi Fountain placed it below street level to make the flow of water seem more dramatic.

The fountains of Versailles depended upon water from reservoirs just above the fountains. As King Louis XIV built more fountains, he was forced to construct an enormous complex of pumps, called the Machine de Marly, with fourteen water wheels and 220 pumps, to raise water 162 meters above the Seine River to the reservoirs to keep his fountains flowing. Even with the Machine de Marly, the fountains used so much water that they could not be all turned on at the same time. Fontainiers watched the progress of the King when he toured the gardens and turned on each fountain just before he arrived.

The architects of the fountains at Versailles designed specially-shaped nozzles, or tuyaux, to form the water into different shapes, such as fans, bouquests, and umbrellas.

In Germany, some courts and palace gardens where situated in flat areas, thus fountains depending on pumped pressurized water were developed at a fairly early point in history. The Great Fountain in Herrenhausen Gardens at Hanover was based on ideas of Gottfried Leibniz conceived in 1694 and was inaugurated in 1719 during the visit of George I. After some improvements, it reached a height of some 35 m in 1721 which made it the highest fountain in European courts. The fountains at the Nymphenburg Palace initially were fed by water pumped to water towers, but as from 1803 were operated by the water powered Nymphenburg Pumping Stations which are still working.

Beginning in the 19th century, fountains ceased to be used for drinking water and became purely ornamental. By the beginning of the 20th century, cities began using steam pumps and later electric pumps to send water to the city fountains. Later in the 20th century, urban fountains began to recycle their water through a closed recirculating system. An electric pump, often placed under the water, pushes the water through the pipes. The water must be regularly topped up to offset water lost to evaporation, and allowance must be made to handle overflow after heavy rain.

In modern fountains a water filter, typically a media filter, removes particles from the water—this filter requires its own pump to force water through it and plumbing to remove the water from the pool to the filter and then back to the pool. The water may need chlorination or anti-algal treatment, or may use biological methods to filter and clean water.

The pumps, filter, electrical switch box and plumbing controls are often housed in a "plant room". Low-voltage lighting, typically 12 volt direct current, is used to minimise electrical hazards. Lighting is often submerged and must be suitably designed. High wattage lighting (incandescent and halogen) either as submerged lighting or accent lighting on waterwall fountains have been implicated in every documented Legionnaires' disease outbreak associated with fountains. This is detailed in the "Guidelines for Control of Legionella in Ornamental Features" Floating fountains are also popular for ponds and lakes they consist of a float pump nozzle and water chamber.