blog.gov.je
Residents across the northern parishes will be aware of the significant roadworks currently under way as part of the Northern Sewer Network Upgrades. These works represent one of the most important infrastructure investments being made to protect homes, businesses and the environment for decades to come.
At the heart of the project is the replacement of ageing sewer pipes that were originally installed in the mid‑1970s and is now reaching the end of its design life. In total, the project will deliver approximately 2.5 kilometres of new sewer, increasing the pipe diameter from 400mm to 600mm to safely carry larger volumes of wastewater.
This upgrade is essential. When Jersey’s Bellozanne Sewage Treatment Works was first constructed in 1959, it was designed to serve a population equivalent of approximately 57,000 people. Today, Jersey’s population is closer to 105,000, and demand on the sewer network has increased accordingly. Parts of the northern network are already operating at full capacity. Without intervention, the risk of sewer flooding and environmental harm would continue to rise, particularly during periods of heavy rainfall.
The new sewer is being installed beneath the centre line of La Grande Route de St Jean. This is necessary because the road is already congested with existing buried services (electricity, telecommunications, water, gas and drainage) and properties on both sides of the road are connected to the sewer, meaning that each existing connection needs to be carefully transferred onto the new pipe. In places, the excavation is over four metres deep, requiring full road closures throughout the project so that the work can be carried out safely and efficiently. As each section is completed, the working area moves on and the road behind is reopened.
Planning for this project began several years ago. The Infrastructure and Environment team has worked closely with parish roads committees, the Honorary Police, emergency services, utility companies, local stakeholders and Liberty Bus to minimise disruption wherever possible. A series of public drop‑in sessions were held ahead of the works to explain the plans, listen to local concerns and shape how the project would be delivered. That engagement is ongoing, with regular updates shared through parish channels and the Government of Jersey website.
To minimise overall disruption, Phases 1A and 1B of the project are being delivered concurrently. This approach reduces the total construction programme to approximately 18 months, compared with an estimated duration of up to three years if the phases had been delivered separately. Progress is being made steadily: Phase 1A has now completed approximately 555 metres of new sewer, representing 37% of that phase, while Phase 1B has completed around 478 metres, or 47%.
The sewer being installed will ultimately serve many hundreds of properties across the northern parishes from Le Fontaines (St John) to Jersey Zoo, as well as supporting future housing and protecting the capacity of the Bellozanne Sewage Treatment Works. Construction is progressing section by section and remains planned to continue through to 2027. While this inevitably causes inconvenience in the short term, these upgrades are a long‑term investment in Jersey’s health, environment and infrastructure resilience.
I&E would like to thank residents and business sincerely for their patience and cooperation while this essential work continues.
For up to date information, Islanders are encouraged to visit: gov.je/StJohnDrainageUpgrades