Thirlmere Aqueduct Refurbishment
Lake District to Manchester (134km length), UK · 2005-2010 (ongoing program, with significant work in 2007) · Over £2.7 million (construction spend in four weeks during 2007, part of a larger AMP4 program)
The judgement call
Account-gated at launchThe adoption of a single contractor (Daniel Contractors Ltd) for the 2007 outage improved coordination compared to the previous year's multi-contractor approach. - The use of advanced communication systems (m-com) and safety measures significantly enhanced worker safety in the confined aqueduct environment. - The project highlighted the importance of detailed pre-contract surveys for identifying risks like radon and potential ground instability. - The rapid response and effective teamwork in addressing the base heave incident prevented a potential progressive collapse. - Public engagement through local newspapers and television was used to keep the community informed.
Key engineering challenges
Refurbishing a 100+ year old aqueduct, operating entirely by gravity. - Working within confined spaces, requiring robust health and safety protocols (e.g., m-com communication system, forced ventilation, radon monitoring). - Addressing defects like hollow bases and base/wall joint issues, which could lead to ground loss and undermining of the aqueduct. - Dealing with unexpected discoveries, such as a base heave and ground ingress during inspection, requiring emergency repairs. - Managing a rolling program of inspection and refurbishment across 134km with over 100 separate work sites.
Project facts
- Client / owner
- United Utilities
- Lead contractor
- Daniel Contractors Ltd (for 2007 outage); Planned Maintenance (Pennine) Ltd (contributor)
- Lead designers
- MWH (Programme Manager Ian Armitage)
- Project type
- refurbishment
- Scale
- 134 km long aqueduct; 82km single line tunnel/conduit (approx. 2.1m square); 52km of 4 parallel pressure pipelines; supplies up to 250 million litres of raw water per day.
- Disciplines
- civil; structural; geotechnical; hydraulic
- Standards & frameworks
- —
Sources: "Thirlmere Aqueduct Refurbishment", Paul Anderton & Ian Armitage, UK Water Projects 2008, https://waterprojectsonline.com/wp-content/uploads/case_studies/2008/Thirlemere-Aqueduct-Refurbishment-2008.pdf - "Thirlmere Aqueduct: Supplying Water to Manchester", Institution of Civil Engineers (ICE), https://www.ice.org.uk/what-is-civil-engineering/infrastructure-projects/thirlmere-aqueduct-and-reservoir - "Refurbishment of the Thirlmere Aqueduct (United Kingdom)", I.D. Armitage, ASCE Library, https://ascelibrary.org/doi/10.1061/41069%28360%29122