Eastern Road Rising Main Rehabilitation: Protecting Portsmouth’s Network and Langstone Harbour

Located beneath Eastern Road, one of only three main routes on and off Portsea Island, the 600mm rising main sits directly beside Langstone Harbour, one of the UK’s most environmentally sensitive marine areas. Each failure risked traffic disruption, emergency works, customer impact and potential environmental harm.

Southern Water needed a permanent solution that could strengthen the asset without creating months of disruption above ground.

Cappagh Browne was appointed as principal contractor, working with Lining Division Ltd to deliver a specialist trenchless rehabilitation scheme across five phases over 18 months. The result was a controlled, low-impact repair that protected a critical transport route, improved network resilience and safeguarded Langstone Harbour throughout delivery.

The challenge

Eastern Road is a vital route into Portsmouth. Traditional excavation would have meant lane closures, diversions, noise, spoil removal and extended reinstatement works.

The environmental setting raised the stakes further. Langstone Harbour is protected by MPA, SPA and Ramsar designations, requiring tight control over pollution risk, resin integrity and site activity throughout the works.

Access was also restricted in several locations, including a caravan park area where the team needed to reduce impact on residents and avoid unnecessary disruption.

The brief was clear: deliver a resilient repair, keep Portsmouth moving and protect a sensitive marine environment.

The solution

Cappagh Browne led a no-dig rehabilitation strategy using a glass-reinforced, pressure-rated cured-in-place pipe liner.

Working with Lining Division Ltd, the team installed Fero Force liner technology with the VeriCure Cure Monitoring System. This marked the first UK use of Fero Force in a Ramsar-protected environment.

VeriCure uses fibre-optic temperature sensing to monitor the full liner cure in real time. This gave the team live confirmation that each section had cured correctly and provided digital proof of integrity for Southern Water.

The approach reduced the need for excavation, shortened surface disruption and improved control over quality, safety and environmental risk.

In one constrained section, a 280m liner was installed through the caravan park area, reducing impact on residents and avoiding the need to remove a property. Across one seven-day period, 700m of lining was installed.

Delivery with control

The project was delivered in five phases over 18 months, with careful planning around traffic, access, weather, environmental controls and stakeholder communication.

Residents, businesses and local stakeholders were kept informed through letters, emails, public drop-ins and dedicated liaison support. Works were planned around off-peak and night-time periods where appropriate to minimise disruption.

On site, Cappagh Browne managed health and safety controls, environmental protection, programme sequencing and coordination with Lining Division Ltd. and partners. Long-duration curing operations were monitored continuously, supported by remote access to live cure data.

The project achieved zero health and safety incidents and zero pollution incidents.

The outcome

The completed scheme gave Southern Water a stronger, more resilient rising main on one of Portsmouth’s most important transport corridors.

The project reduced the risk of future bursts, emergency repairs and disruptive road closures, while protecting Langstone Harbour throughout delivery.

Key outcomes included:

• Rehabilitation of a 600mm rising main beside Langstone Harbour
• Delivery across five phases over 18 months
• First UK use of Fero Force in a Ramsar-protected environment
• WRc-approved VeriCure real-time cure monitoring
• 700m of lining installed in one seven-day period
• 280m liner installed to reduce residential disruption
• Zero pollution incidents
• Zero health and safety incidents
• Significantly reduced excavation, spoil and reinstatement

Setting a benchmark for no-dig wastewater delivery

Eastern Road shows how ageing wastewater assets can be renewed safely in complex, high-risk locations.

Through careful planning, strong partnership and specialist trenchless technology, Cappagh Browne helped Southern Water strengthen a critical asset, protect a sensitive marine environment and reduce disruption for the Portsmouth community.