Seven Sisters network reinforcement

Client: Thames Water

Duration: Oct 2022- ongoing

Situation

After a Trunk Mains burst in Queen’s Drive in 2019 flooded properties and left residents without water, Thames Water decided to strengthen three major water pipes to prevent future incidents.

The work required involvement from numerous stakeholders, including local residents, businesses, Transport for London (TfL), and borough councils. Effectively identifying and managing these stakeholders has remained crucial to the project's continued success.

Task 

Our team rehabilitated 600m of an existing 36-inch cast iron water main between Seven Sisters Road and Finsbury Park Road, in Hackney, London.

Action

The repair of three main water pipes between Seven Sisters Road and Finsbury Park Road is being completed in multiple phases to rehabilitate the existing 36” CI mains and reduce future burst risks:

• Phase one involved the Maiden Lane main from Seven Sisters Road to Finsbury Park Road.
• Phase two covered the main from Finsbury Park Road to Myddleton Avenue.
• Phase three addressed the secondary main on Maiden Lane main from Finsbury Park Road to Myddleton Avenue.
• Phase 4 Crouch Hill main from Finsbury Park Road to Saint John’s Court is currently being planned.

Due to the number of stakeholders involved, customer/stakeholder impact assessments meant we could break down the requirements of the project. We then mapped these requirements and developed our Stakeholder Engagement Plan, which successfully made sure each stakeholder felt their needs were being met.

Innovation

An innovative method called Die Draw method was decided as most suitable for Phases one and two as standard pipe replacement would have been disruptive to homes and communities through road closures and noisy construction work.

Die Draw technology is where the liner pipe is elastically reduced in diameter, allowing the thermoplastic liner to be fitted as a tight-fitting liner within the original pipe. This marked the first use of its kind on a Thames Water site, minimising  impact to customers, reducing carbon and keeping water flowing for the future. 
Another team from M Group Water provided emergency confined space training and supported our mains team with an internal lining repair to part of the main.

Results

• We’ve successfully relined 500m of the 6000m of the water main, eliminating 19 leaks.
• We’ll now complete the final 100m using an internal lining, designed and to be installed by part of M Group Water.
• Once phase one is complete, we will continue onto phase two, which will finish at Myddleton Avenue using the Die Draw technique.

“I was really impressed with the level of service provided by the team and how well the training was received on-site. During the emergency trial run, the team worked efficiently and professionally to rescue the operative.”  

Safety Health Environment and Quality advisor 

Hear from Martin Padley, Water Director atThames Water, here: