Wonder how Vienna gets its crystal-clear water? We are standing before a marvel of engineering: the 2. Wiener Hochquellwasserleitung. This Second Vienna Mountain Spring Pipeline delivers fresh spring water directly from the Hochschwab area in Styria to Vienna.
The 2. Wiener Hochquellwasserleitung was built to augment the 1. Wiener Hochquellwasserleitung. This became necessary because Vienna’s groundwater quality declined due to the lack of proper sewage systems. Epidemics were common. Private water pipelines couldn’t meet the city’s growing need for clean drinking water.
The existing Kaiser-Ferdinands-Wasserleitung had issues too. Initially, it provided good-quality drinking water, but the water quantity and quality decreased over time. It even became a health risk. The city then built the first high-spring pipeline from the Rax and Schneeberg area. This pipeline delivered high-quality water. However, it supplied less water than expected during winter months.
Studies were conducted for a second high-spring pipeline. Possible source areas were explored in Lower Austria, Styria and Upper Austria. The flow rate of the springs was measured over several years. The focus was on the winter months. High mountain springs had the lowest yield during this time unlike the springs of the low mountain range.
The city council approved the construction of a second high-spring pipeline from the Salza area. They demanded a minimum supply of 200.000 cubic meters of drinking water. The Pfannbauerquelle was found as a strong additional source. It was connected to the I. Wiener Hochquellwasserleitung via tunnels.
The Vienna City Council made three fundamental decisions. A second high-spring pipeline should be constructed. The Vienna City Building Authority was commissioned to develop a project with a capacity of 200.000 cubic meters of water daily. The financing of the construction had to be ensured.
The II. Wiener Hochquellwasserleitung’s construction began in 1900 and was completed in 1910. Its full name was II. Kaiser Franz Josef-Hochquellenleitung. It transports up to 217 million liters of water daily. The pipeline is 180 kilometers long. The water overcomes a height difference of 360 meters in 36 hours and flows through 100 aqueducts.
To ensure a uniform gradient, the route follows the terrain. The gradient is also used for electricity production along the pipelines. The water flows from the endpoints of the high-spring pipelines into 31 water reservoirs. These reservoirs have a storage volume of 0.9 million cubic meters. Two additional reservoirs outside Vienna increase this volume to 1.6 million cubic meters. This equals the water consumption of all Viennese people in about four days.
The 2. Wiener Hochquellwasserleitung consists of many impressive structures. There are 100 aqueducts, siphons, and pipe bridges. The longest of these aqueducts is the Luegerbrücke near Scheibbs. It is 271 meters long. All aqueducts of the II. Wiener Hochquellenleitung are protected as historical monuments.
The 2. Wiener Hochquellwasserleitung not only quenches Vienna’s thirst but also generates clean energy. The city has 13 water power plants. They generate around 65 million kilowatt hours per year. This amount equals the electricity demand of a city like St. Pölten.
So, the next time you take a sip of Vienna’s tap water, remember the 2. Wiener Hochquellwasserleitung. It is a feat of engineering and a testament to Vienna’s commitment to providing its citizens with the highest quality water. It ensures that Vienna remains a city where crystal-clear water flows freely.