Source of the drinking water

The Landeswasserversorgung (state water supply) obtains the water for the drinking water supply from three different sources: groundwater from Donauried and from Burgberg; spring water – strictly speaking also ground water, which appears on the surface – from the Buchbrunnen spring near Dischingen; and river water from the Danube.

Groundwater from the
Swabian Alb region

Donauried in Württemberg is one of the most important groundwater reservoirs in the country. It holds around a billion cubic metres. The water reserve, which fills during the winter part of the year, is available in the hot summer months when the demand for water is high.

The groundwater from Donauried represents the main pillar in the supply of drinking water to association members of the Landeswasserversorgung. Where required, the central distribution and treatment take place at Langenau waterworks. The catchment area of the groundwater reserve in Donauried in Württemberg lies on the high plateau of Swabian Alb, northwest of the basin. The seeping rainfall in the Swabian Alb region flows to Donauried in underground crevices and fissures that branch in all directions. The average age of the karst groundwater in Donauried is around 12 years. This explains why pollution at the groundwater catchment appears and abates with a significant delay; we speak of the “long memory” of the groundwater.

To cover the rapidly increasing demand for water, Burgberg waterworks were constructed in the Hürbe valley between 1964 and 1966. Since 1990, the option has been available to extract up to 500 litres of karst groundwater per second from the three wells of the waterworks during periods of peak demand.

Facts and figures

Groundwater from Donauried

204 groundwater wells
6Container systems
2.500Litres per second, peak extraction
315Square kilometres, catchment area
8,8Litres per second and square kilometres, groundwater recharge rate
8Metres, average extraction depth

Like a giant underground lake – The Donauried between Langenau and Sontheim is an important groundwater reservoir. The Landeswasserversorgung transports the drinking water from
here to large parts of Baden-Württemberg.

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Drinking water from Buchbrunnen spring

Back in 1929, the Landeswasserversorgung purchased a large karst spring, Buchbrunnen spring, in the Egau valley near Dischingen in the east of Swabian Alb. The bulk ratio of Buchbrunnen spring is very balanced. This is extremely favourable for use of the spring for the drinking water supply. Firstly, it guarantees the required minimum extraction quantity required for a reliable drinking water supply at all times. In addition, the changes in quality of the karst groundwater move within very narrow limits. Only after prolonged heavy rain and during snow melting does mineral turbidity occur in the spring water.

In 1952, the Landeswasserversorgung decided to use Buchbrunnen spring for the public drinking water supply. Egau waterworks became operational in 1957.

Facts and figures

Buchbrunnen spring


Litres per second, maximum extraction rights (depending on water flow from the Egau)

843Litres per second, average spring discharge
14,6million cubic metres, water extraction

Annual figures 2021

Idyllically located –
On the Egau creek near
Dischingen, the Landeswasserversorgung waterworks
lies at the impressive
spring head of
Buchbrunnen spring.

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River water from the Danube

As in the previous decades, a further rise in the demand for water was also expected around 1965. New options for the provision of drinking water had to be explored. As tight limits had been set on the further extraction of ground and spring water in the eastern area of the state of Baden-Württemberg, the decision was made to extract river water from the Danube and treat it to produce high-quality drinking water. Less than one percent of the water flow of the Danube is used here. In 1973, Langenau waterworks became operational on “Spitziger Berg” mountain on the edge of the Donauried. As the site of the untreated water pumping station is at Leipheim in Bavaria, a state treaty for the extraction of Danube water was formed between Baden-Württemberg and Bavaria. In a multi-stage process, the river water extracted at Leipheim is treated to produce drinking water at Langenau waterworks.

Facts and figures

Danube water

45,3Million cubic metres extraction volume
1.100Litres per second average continuous extraction
45Percent proportion of total delivery from the Landeswasserversorgung

Stage treatment process

1Percent of the total water flow of the Danube extraction volume for drinking water production

Annual figures 2021

Researched and tested –
The process for drinking
water extraction from
the Danube has been
optimised over many years
of trials.

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