Vienna Waterworks usually supplies its customers with the best spring water from the mountains. Some 400,000 m3/d is required to supply the city of Vienna, met entirely from 32 springs abstracting to two big spring water supply mains, each of which takes half of the total amount of water put into supply. Other water sources are, however, needed in case of failure or necessary repairs on either of the two spring water supply mains or during times of increased water demand, such as hot, dry summer days.
In the 1870's the construction of the water supply system for Vienna was started. These two spring water supply mains are in operation since this time without any general rehabilitation. Therefore, Vienna Waterworks follow the all-over-strategy of the ability to substitute one of these two spring water mains with other water sources. One part of these alternative water sources is Waterworks Moosbrunn.