Water was pumped to the Castle even during King Sigismund's reign; then King Matthias has the sources on Svábhegy diverted to the Castle. The Ottomans used a similar solution to ensure a water supply.

After Buda was reconquered, an aqueduct from Svábhegy provided fresh water for the city's inhabitants, but water was also needed from the Danube. Horse-powered pumps overcame the difference in elevation. The machinery deployed after the expulsion of the Ottomans proved to be insufficient and was replaced by a new solution designed by Farkas Kempelen in 1777, which was in turn expanded in 1780.

At the time, people claimed that Buda had much better water than Pest from these two sources, despite the river's water not being the cleanest.

The square building on the right of Szentháromság Square was the well, where water arrived from Svábhegy
(Source: FSZEK, engraving by Károly Schwindt, 1830s) 

The city continuously improved its water network. In 1831, under the leadership of Buda's urban engineer, József Baczó, the network was expanded, and lead pipes replaced with iron pipes.

However, the horse-powered pump was also outgrown by the middle of the 19th century, and in 1855 the city decided to construct a new water pump. Plans were made to modernise the old pump-house. The new steam pump was thus also located under 3 Fő Street, and it also moved the Danube's water up into the Castle. However, the water was purified somewhat by being passed through a gravel and sand filter.

Adam Clark not only built bridges and tunnels but also worked on Buda's water network drawing by Miklós Barabás, 1840, source: OSZK) 

Adam Clark was commissioned to plan and oversee the renovation. The engineer charged 14.000 Forints for his work.  The 31 July 1855 of issue of Budapest Hírlap wrote:

“The scarcity of water was often felt by the residents of the Castle in Buda, especially in dry weather. This problem will soon be solved, as Mr Clard is no working on a steam-powered pump to be installed not fat from Chain Bridge which will move 3500 akó [roughly 190 000 l – trans.] to the Castle every hour

Construction was quick, and on 12 January 1856 Hölgyfutár reported the following:

“The steam-engine made by Mr. Adam Clark for the water pump in Buda has already been tested before a committee and has been found to excel in all respects. The machine is now ready to start pumping any minute. If the residents of Buda will be as well supplied with everything else as they are with water, then we'll all move over there for Saint George's Day!"

The machine became operational a few days later, on 16 January 1856. The new machine pumped 2000 cubic metres of filtered water into the Castle every day. It not only supplied eight public wells but pushed water to 38 buildings through 6200 metres of piping. Beyond Buda Castle, it supplied the residents of the Tabán, Viziváros and Krisztinaváros, a total of 40 thousand people. Of course, water usage was quite different from that of the current age. All in all 104 toilets were connected to the network, but only 7 bathrooms.

The pump house operated under what is today 3 Fő Street for a long time. The machinery designed by Clark was demolished during the construction of the new pump house, and a residential building was built in its place according to the plans of Hugó Máltás
(Photo: Balázs Both/Pestbuda.hu) 

Filtration was completed in a system designed by the city's fountain master János Hofbauer. Consisting of six connected cisterns, the system was eventually forgotten and only rediscovered by accident in 2009.

This filtration was not satisfactory to ensure public health as it did not prevent the spread of diseases. This also contributed to the fact that Clark's machine was not enough to meet the rapidly growing city's demands for long.

The Várkert Kiosk originally housed the waterworks built to replace the pump designed by Adam Clark, in other words, it was once a pump house (Photo: FSZEK, Budapest Collection, photographs of György Klösz, the 1880s) 

With increased capacity and improved filtration, the new water pump was built elsewhere and was hidden in what is today the Várkert ('Castle Garden') Kiosk The building was designed by Miklós Ybl and built between 1875 and 1882. It originally served as a pump house, and its tower was designed to hide the steam pump's exhaust chimneys. Thus, a new system replaced Clark's design and laid the foundations of the modern water network of Budapest, which greatly increased sanitation.

Cover photo: Buda as seen in the 1840s (Source: FSZEK, Budapest Collection)