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 therefore one of the most important in terms of water management. At normal reservoir levels, the reservoir holds 134.5 million m³ of water with a reservoir surface area of 10.37 km².
It dams the river water of the Möhne and thus contributes to securing the drinking water supply for over five million people. The dam also provides flood protection for the lower sections of the river, as well as power generation and recreation.
The Möhne Dam was destroyed during the Second World War by a British bombing raid (Operation Chastise) on the night of May 16th to May 17th, 1943.
At this time of year, the lake was full. In order to bypass the defenses, the Allies used bombs specially designed for this operation, known as rolling and rotating bombs.
Today, you can see a replica of one of these bombs inside the Möhne Dam. However, only 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 catch nets towards the dam wall after being dropped, hit there 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 wall was destroyed over a length of 77 meters and a height of 23 meters. The resulting tidal wave killed around 1600 people. Most of them died in a prisoner-of-war camp located directly below the dam. A memorial at the former Himmelpforten monastery commemorates this today. Another memorial can be found in Neheim, where the 12-metre-high flood wave hit the town hard.
The purpose of this attack was to disrupt the armaments industry in the Ruhrgebiet.
Despite the tense situation, reconstruction was initiated immediately after the attack with the help of thousands of workers. 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 boat service and a tourist information office are located at the dam. Both are open during the season from Easter to October.
Near the dam wall, you can experience and discover the landscape, water and forest at the Möhnesee Water and Forest Landscape Information Center.
The Möhne power station is also located at the equalizing pond.
The dam is registered as a monument in the Möhnesee municipality's list of monuments.