The water reservoir for Grödig and the city of Salzburg is the Untersberg. The springs and wells at the foot of the mountain provide about 90% of the water needed by the city. The water from the springs as well as the ground water from the well in St. Leonhard are naturally pure because the required drinking water can be tapped where it occurs by nature: at the foot of the high mountain massif known as the Untersberg. The water supply is supervised by the Grödig Water Cooperative, a public corporation with autonomous civic administration. The water is regularly analysed according to the legal regulations and testified by experts as being of excellent quality. The water has a pH-value of 7.68 and an overall hardness of 8.48 according to the German scale of hardness. All the values are well below the permitted limits. Doctors consider the flawless drinking water to be extremely healthy and recommend it. When Salzburg was ruled by prince-archbishops, water-riders were sent daily to fetch the valuable commodity for the princely dining tables in the residential city – the village and surrounding area is still known as Fürstenbrunn – the well of the princes.