Esch-sur-Sûre Dam

The Esch- sur -Sure Dam is located at Esch- sur -Sure, Luxembourg City. The oxygen, which rises in the Ardennes, and its numerous tributaries deliver 175-240 million cubic meters of water annually.

The project

When the natural Luxembourg drinking water reserves were no longer sufficient in the late 1940s, the Luxembourg government decided in the early 1950s to draw on surface water for drinking water.

It required a clean, year round flowing water body in the vicinity neither larger cities still industries were located. The problem of sufficient water reserves could only be solved by a dam, as there are no large natural lakes in Luxembourg. The narrow valley of the Sauer and the rocky shore, which give the dam good and firm grip, offer good conditions for the creation of an artificial lake.

The construction period for the 47 meter high arch dam was nearly three years, from 1955 until 1958. The wall thickness varies from 1.5 m at the crown and 4.5 meters at the foot of the wall.

The reservoir covers at maximum filling an area of ​​3.8 square kilometers and has a capacity of 60 million cubic meters of water. The lake is up to 43 meters deep.

In the valley there are several mills and farms, whose residents had to be moved before the construction of the dam were. Today, divers can still visit at these sites in about 30 meters depth the remains.

In order to keep the sea water as clean as possible, was built below Pont Misère and close to the city Bavigne Vorstaumauern with storage heights of 9.6 meters and 23 meters. There driftwood, logs and sand particles are trapped before they can get into the lake.

The SEBES

SEBES stands for Syndicat des Eaux du Barrage d' Esch- sur -Sure. The Syndicate was launched in 1962. Members are the four responsible for nationwide water supply of the country syndicates SES, DEA, Sidere and SEC as well as the city of Luxembourg.

The tasks of the SEBES include compounding of the raw water from the reservoir of Esch- sur -Sure to drinking water and subsequent delivery to the distribution networks of the different communities. Only by building the SEBES plants in 1969 the central water supply in the country was possible. Now, after more than 35 years, about 80 percent of the population are supplied with SEBES water.

The emptying of the reservoir

The entire reservoir was only emptied into his inventory time twice: the first time in 1969 to allow the installation of a fixed raw water intake line, the second time in 1991 for repair purposes and for establishing a height-adjustable suction arm (see below) in 140 meters distance to the dam.

The emptying of the reservoir occurs only under an official agreement with the dams in the valley to avoid flooding. When emptying the locks of the dam are opened more than 15 centimeters. The air suction occurs at the sluice opening is huge. Workers must rope up there, not to be carried away. The whole process then takes about four weeks. Refilling takes about three months depending on the season and rainfall. The lake is not entirely empty, it shrinks back to the original flow size, compared to full sea as a trickle effect. The fish that swim in the lake which must then be captured by hand and noteinquartiert in an artificial lake near the SEBES halls.

When emptying 1991 many items to light, including some boats, bicycles and a large amount of discarded household appliances arrived. The next complete emptying of the dam is planned for 2020.

The height-adjustable suction arm

The height-adjustable 16 -meter suction arm in the reservoir of Esch- sur -Sure was a child of necessity. When the plague of algae of the reservoir rapidly increased in the 1980s, had a decision to be made. The fixed raw water intake line at the foot of the 47 -meter-deep dam sucked increasingly more and more algae. So they decided on a completely new design:

A 22 meter high, height adjustable suction arm that can pump out from the cleanest layer of the dam in the different seasons raw water. He was installed during the evacuation in 1991 at a distance of about 140 meters to the dam.

There, the raw water in the water protection zone 1 is taken. The suction arm is seated on a frame which is anchored by four concrete blocks in the ground. As a building material for the frame and the suction arm stainless steel was used. From far has considered the construction, the removal device is called, a certain resemblance to an oil rig.

The water is conveyed by means of centrifugal pumps in a raw water tank which has a capacity of about 5000 cubic meters. The container is at the highest point of the treatment plant, the water flows through independently thanks to gravity all other stations in the system.

The diameter of the suction arm is 70 inches; the discharge capacity is 1,200 liters per second.

Hydroelectric power station

The high pressure of the water is used for electricity production. In the two lower bulkheads of the dam two Francis turbines were installed with a capacity of around 5500 kilowatts each. On the small section of the river below the dam spread over a length of four and a half kilometers, three weirs and a compensation defense. These are a total of seven Francis turbines with a total capacity of 1850 kW.

Operator of the plant is the joint-stock company SOLER, which is in each half-owned by the energy supplier Enovos and the power plant company, Société Électrique de l'Our, and who is also responsible for the hydropower plants in Ettelbrück and Rosport.