Derwent Valley Reservoir Complex – Derbyshire

Specialist access inspections to around 10km of water diversion tunnels owned by Severn Trent Water plc.

The challenge

The Derwent Valley Reservoir Complex consists of Howden, Derwent and Ladybower Reservoirs. Together, these form the largest body of open water in the Peak District and Derbyshire, with a combined capacity of nearly 464 billion litres.

Engineering Consultancy

As experts in difficult and confined space access, Inertia Consulting Ltd was appointed to carry out specialist access inspection and survey of around 10km of the raw water diversion tunnels that feed the reservoir complex from nearby rivers.

As well as the issue of accessing the tunnels themselves, other challenges included their location in remote, ecologically sensitive areas with access only possible using minor roads and by crossing farmland and a narrow railway bridge. For the project to succeed, we therefore needed to collaborate effectively with multiple stakeholders.

“Inertia are an extremely professional company providing an excellent service which always delivers highly accurate detailed surveys with cost effective solutions. They only use highly skilled competent staff that always put the needs of the client first.”

John Wing, DVA Resilience Project Facilitator, Severn Trent Water plc

The temporary works required to support the inspections were designed and managed in-house by the Inertia Consulting team. We designed temporary damming, over-pumping and access for safe confined spaces entry, before undertaking a touching distance inspection to Principal Inspection standards.

The temporary works and inspection process required a range of specialist access techniques. Our team hold all the necessary skills and credentials to deliver these services in-house, as well as ISO9001:2015 Quality Management, ISO 14001:2015 for Environmental Management and ISO45001:2018 Health & Safety and Risk Management.

The outcome

Thanks to our attention to detail and the innovative methods used for design and implementation, plus the careful and diplomatic management of key stakeholders, the project was a success. Our inspections have enabled the water supply for these important strategic reservoirs to be safeguarded, whilst minimising environmental impact.

The project team
  • Severn Trent Water plc – the Client
  • Inertia Consulting Ltd – Inspection and Survey Consultant