Technical data of the Möhne dam
Lake Möhne, with a capacity of around 134.5 million cubic metres of water, is over ten kilometres long and 36 metres deep at its deepest point when full. The surface area of the water can also be around ten square kilometres at full capacity. The dam wall consists of quarrystone masonry and is built according to the Intze principle. The wall crest has a length of 650 metres. The so-called equalising pond is located directly below the dam.
| Water management | |
| Reservoir capacity | 134.5 millionm3 |
| of which Möhne reservoir | 7 millionm3 |
| of which Heve reservoir | 0.8 millionm3 |
| of which equalisation ponds | 0.66 millionm3 |
| Reservoir level above NHN | 213,74 m |
| Reservoir level of the equalising pond above sea level | 183,65 m |
| Catchment area | 436.29 km2 |
| Reservoir surface area at reservoir level | 10.37 km2 |
| Flood protection area (from November to April) | max. 10 millionm3 |
| Dam wall | |
| Gravity dam made of quarry stone | |
| Greatest wall height | 40,3 m |
| Crown length | 650,0 m |
| Largest wall width | 34,2 m |
| Crown width | 6,25 m |
| Base outlets | |
| 4 steel pipes laid in galleries, diameter 1.40 m, arranged in 2 groups of 2 outlets each | |
| Max. capacity | 25m3/s each |
| Spillway | |
| In order to enable an overflow during flood peaks 105 openings are embedded in the top of the wall below the carriageway. into the top of the wall below the carriageway. The water flowing down is channelled on the air side of the dam wall through the protruding quarry stone blocks the equalising pond serves as a stilling basin. The dam last overflowed in August 2007 as a result of very heavy rainfall and the dam was already relatively full before the of the rainfall. The penultimate overflow event was in 1984. | |
| Heve forebay (homogeneous clay embankment) | |
| Reservoir level above NHN | 213,74 m |
| Summer water level above NHN | 213 m |
| Dam height | 12 m |
| Crown width | 12 m |
| Crown length round | 320 m |
| Largest base width | 41 m |
| Wamel forebay (homogeneous clay embankment) | |
| Reservoir level above NHN | 213,74 m |
| Summer water level above NHN | 212,5 m |
| Dam height | 14 m |
| Crown width | 12,65 m |
| Crown length round | 580 m |
| Largest base width | 75 m |
| Main power station | |
| Supply line through steel-armoured tunnel: | |
| Diameter | 3,40 m |
| Length around | 200 m |
| Diameter of the branch pipe to the turbines | 2,30 m |
| 2 vertical Kaplan turbines with three-phase synchronous vertical generators, per unit: | |
| Effective gradient | 32,0 m |
| Siphoning capacity | 12m3/s |
| Power output | 3,500 kW |
| Average total annual energy production | 12.9 million kWh |
