Barhale has been awarded a significant contract worth £14.8 million to refurbish sections of the historic New River aqueduct in London. The New River, over 400 years old, requires urgent repairs to manage leakage and sustain its structure. Innovative techniques will be employed to minimise environmental impact and disruption. The project relies on strategic partnerships for expertise in construction and ecology. Completion is projected for September 2025.
Barhale has taken on the vital task of refurbishing the New River aqueduct, one of London’s oldest water infrastructure assets, with a contract value of £14.8 million. The New River, which dates back to 1613, originally supplied central London with water sourced from Hertfordshire. However, due to its age, the aqueduct is now facing significant issues, particularly in Hornsey and Waltham Cross, where it experiences leakage and structural erosion. Barhale’s assignment includes strengthening the northern waterway side in Hornsey using advanced sheet piling methods to address these concerns effectively.
The New River’s path through urban areas poses challenges due to restricted access, necessitating innovative solutions such as the use of pontoon barges to transport equipment. This approach allows Barhale to undertake necessary works without exacerbating noise or visual disruption for residents. As explained by Thames Water’s senior project manager, Rachel Whiteman, while small repairs have been attempted over the years, a large-scale upgrade is imperative to tackle underlying leakage effectively.
Thames Water initially considered constructing a concrete channel, yet Barhale proposed an alternative: sheet piling, deemed more cost-effective and environmentally harmonious. The use of silent piling technology, specifically the Giken press-in rig, exemplifies Barhale’s commitment to minimising disturbance while ensuring the project’s success. These efforts aim to blend new constructions seamlessly with the surrounding ecology, preserving the historical integrity of the New River.
Complementary to the construction efforts in Hornsey, Barhale will extend its refurbishment to Waltham Cross by reinforcing a 1.1km stretch with varying lengths of sheet pile. This will achieve contact with the impermeable London Clay layer, preventing further water leakage. The innovative technique of utilising pea gravel between old and new piles enhances stability, ensuring the asset’s longevity.
Collaboration with piling specialist Ivor King and OTB Engineering has been crucial in overcoming logistical challenges, like the insufficient load-bearing capacity of the existing tow path. Barhale’s adoption of the Giken Reaction Base system underpinning the installation of sheet piles demonstrates a forward-thinking approach to infrastructure maintenance. Additionally, ecological protection is prioritised, with partnerships like Frog Environmental implementing bubble curtains to contain silt while safeguarding local fauna.
Barhale’s comprehensive approach to refurbishing the New River aqueduct underscores its expertise in managing historic infrastructure projects with minimal disruption.
