By the ;middle of the 19th century Vienna had many epidemics of typhoid and cholera from polluted water. A 95 km long pipeline was built to fetch fresh mountain water from the Rax and Schneeberg mountains south of Vienna. The system, which runs by gravity, was finished in 1873, and now carries some 220,000 cubic meters of water daily - about half of Vienna's water. The pipeline is carried in aqueducts over valleys and in tunnels through the hills. There are three aqueducts inside Vienna itself. This one is in the 23rd district. They were totally renovated 2007-2011.