Geotechnical Investigations for the Pumped Storage Plant Waldeck 2, Germany

The Waldeck 2 pumped storage plant, with a capacity of 2 x 240 MW, is situated downstream of the Edertal Dam to the West of Kassel and was built between 1969 and 1975. Possible future extension of the plant had already been allowed for in its design and construction, including a second pressure pipe at the upper basin intake structure (from which a new waterway and cavern can be constructed without disturbing the operation of the existing plant).

The new waterways consist of a 200 m deep vertical headrace shaft with a connected inclined tunnel, and a 700 m long tailrace tunnel leading to a separate cavern south of the existing plant’s cavern containing a 300 MW asynchronous pump-turbine. The headrace tunnel will be connected to the existing intake structure at the upper basin, while the tailrace tunnel is provided with a separate outlet structure into Affoldern Lake which serves as lower basin.

An additional storage capacity of 450,000 m³ is provided in the upper basin by increasing the maximum operating level by 1.5 m. The elevation of the dam crest was raised by 0.7 m, and wave deflection walls are being installed in order to provide the necessary freebord.

The required additional capacity in the lower basin is being provided by raising the maximum operation water level and lowering the minimum operation water level, in each case by 0.1 m, combined with a modified mode of operation of the upstream Edertal Dam.


E.ON Wasserkraft GmbH, Landshut, Germany

Services Period2009 – 2011
Technical Data
Upper basin
  • Operating volume - existing: 
4,285 M m³
  • Operating volume - extension:
0,450 M m³
  • Depth of vertical shaft:
200 m
  • Length of tunnel (20° inclined):
450 m
  • Diameter of tunnel:
4.75 m
Tailrace tunnel
  • Length:
700 m
  • Diameter:
6.50 m
Pump turbine
  • Gross head:
324 m
  • Capacity:
300 MW
  • Rated discharge - turbine operation:
104.7 m³/s
  • Rated discharge - pump operation:
84.4 m³/s
Related to geotechnical investigations:
  • 4 deep boreholes from surface to define cavern location and orientation
  • Test adit into powerhouse location including boreholes, with borehole scanning, dilatometer, borehole slotting, water pressure tests
  • Boreholes and geophysical survey at outlet structure

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