Urft Dam

Urft Dam
Urft Dam
	MW

The Urft Dam (

Euskirchen

to create the Urft Reservoir (Urftstausee), 2.16 km² in area. The reservoir is also called the Urftsee (Lake Urft).

The Urft Dam, which was constructed during the period 1900 to 1905, and the Urft Reservoir, which was then the biggest reservoir in Europe, having belonged since 1993 to the Eifel-Rur Water Board (Wasserverband Eifel-Rur).

Location

The Urft barrier system that comprises the Urft Dam and Urft Reservoir is located in the

Hohes Venn-Eifel Nature Park

.

Dam wall

The Urft dam is a curved gravity dam with its convex side facing upstream and an earth embankment (an Intze Wedge) on the reservoir side that reaches to about half the height of the dam wall. It is situated around 6.8 kilometres, as the crow flies, west-northwest of Gemünd, the northern part of the town of Schleiden in Euskirchen district.

The Urft Dam was built between 1900 and 1905. The overall plan for the dam was developed by Prof. Dr. Otto Intze from

rubble stone composed of greywacke and slate that was quarried locally and rises 58.5 metres above its base (Gründungssohle). At its crown, it is around 226 metres long and 6 metres wide, and is 50.5 metres wide at its foot. The Urft Dam was also the highest in Europe until the construction of the Bober Dam in the Giant Mountains of Silesia

in 1912.

On its completion, the Urft Dam became the model for many other projects at home and abroad after

industrialization

became increasingly important after the end of the 19th century. The trial impoundment of the river began in November 1904, its use in water management started on 26 August 1905.

North of the Urft Dam and separated from it by the base of a narrow peninsula is the spillway in the shape of an overflow weir with a maximum width of 91 metres which cascades down a total of 33 steps. Within the dam at an interval of 2.5 metres are vertical clay-filled tubes that drain away the water that seeps into the dam wall.

Several bottom outlet towers provide access to inspection walkways at two different depths that enable the state of Urft Dam to be checked. The lower inspection gallery runs along its base joint. From 1994 to 2000 the barrage was thoroughly renovated. Among other things, a problem with the uplift pressure was resolved. It was also given two new inspection galleries that were driven using

blasting

techniques, which have a total length of 320 metres, are an average of 3.10 metres high and 2.40 metres wide, as well as new sealing and drainage and numerous measuring devices.

The Eifel-Rur Water Board celebrated the 100th anniversary of the opening of the Urft Dam on 26 August 2005.

Since the Rur Dam was completed, the Urft dam not only impounds water on its upstream side, but also impounds the waters of the Rur Reservoir (also called the Obersee) on its downstream side up to a depth of 12 metres.

Reservoir

The Urft Reservoir (Urftstausee or Urftsee), which when full is 7.85 km long according to the Deutsche Grundkarte map, although the straight-line distance from the head of the lake to the dam is only about 3.9 km), has a total area of 2.16 km² and holds up to 47.75 million cubic metres of water. The

Heimbach

.

At the northwest end of the snaking waters of the Urft Reservoir and just below the Urft Dam is the Obersee lake, which acts as the main pre-basin for the Rur Reservoir and in which both the Rur and the Urft are impounded. In the Urft Reservoir (322.5 m above sea level (NN)), which is surrounded by wooded countryside, lies the island of Krummenauel (max 339.6 m above NN). The peninsulas at Altenberg (Auf dem Altenberg; max. 351.5 m above NN), Neffgesberg (max 370 m above NN) and Hosterauel (max 366.7 m above NN) jut out into the lake. They can also be reached on foot depending on the water level.