The dam has a length of 650 meters and measures 40.30 meters at its highest point. The Möhne Dam is the second largest dam in the Ruhr catchment area and thus one of the most important in terms of water management. Under normal conditions, the reservoir capacity is 134.5 million m³ of water with a storage surface of 10.37 km².
It impounds the river water of the Möhne and thus contributes to securing the drinking water supply for more than five million people. In addition, the dam serves as flood protection for the lower sections of the river, as well as for power generation and recreation.
The Möhne Dam was destroyed during World War II by a British bombing raid (Operation Chastise) during the night of May 16 to May 17, 1943.
At that time of year, the lake was full. To bypass the defenses, the Allies used bombs specially designed for this operation, the so-called roll - and rotation bombs.
Today, you can see a replica of such a bomb inside the Möhne Dam. However, this is only available on request from the Ruhrverband Möhnesee as part of a guided tour.
With the help of their own rotation, these bombs jumped over the torpedo nets after being dropped in the direction of the dam wall, hit it with little residual momentum, sank and detonated at a depth of 10 to 15 meters. Only one of the bombs dropped reached its target.
The dam was destroyed over a length of 77 meters and a height of 23 meters. The resulting tidal wave killed about 1600 people. Most of the people lost their lives in a prisoner of war camp, which was located directly below the dam wall. A memorial at the former Himmelpforten monastery reminds us of this today. Another memorial can be found in Neheim, where the 12-meter high flood wave hit the town hard.
The purpose of this attack was to affect the armaments industry in the Ruhrgebiet.
Despite the tense situation, reconstruction was initiated with the help of thousands of workers immediately after the attack. The work was completed on October 3, 1943. The wall was not attacked again until the end of the war.
The main landing stage of the Möhnesee passenger shipping company and a tourist information office are located at the dam wall. Both are open during the season from about Easter to October.
Near the dam wall you can experience and discover the landscape, the water and the forest at the Landscape Information Center Wasser und Wald Möhnesee e.V..
The Möhne power plant is also located at the balancing pond.
The dam is registered as a monument in the monument list of the municipality of Möhnesee.