Upper Neuadd Reservoir Ground Investigation


Welsh Water


Merthyr Tydfil



Upon the instructions of Arup (Consulting Engineers), on behalf of Dwr Cymru Welsh Water (Client), Quantum Geotechnical has been commissioned to undertake ground investigation at Upper Neuadd Reservoir, just north of Merthyr Tydfil. The site comprises a Victorian Grade 2 listed dam within the Brecon Beacons National Park. It is bounded to the north by a reservoir, to the south and west by heavy vegetation, and to the east by an access track and small area of car parking. The topography of the site varies, the dam crest is relatively level, and the ground in front of the dam falls from the east and west into the central spillway area, with ground levels further reducing to the south. The site is currently used as a dam and reservoir, operated by Dwr Cymru Welsh Water.

The investigation works included:

  • 6 cable percussive boreholes
  • 14 rotary cored boreholes (6 no. as follow-on from the cable percussive and 8 no. rotary)
  • 2 hand held rotary cores (horizontal into dam face)
  • Permeability Testing: 4 packer/lugeon tests; 2 falling/rising head tests
  • Standpipe installations in 12 boreholes

We held weekly site progress and health and safety meetings with the clients and engineer.