The situation

Part of making sure that our 1.8 million customers have access to safe and reliable drinking water 24/7, 365 days of the year, is transferring water around the network to where it’s needed. With climate change and growing populations putting increasing pressure on water resource availability in our area and across Southern England, being able to move water to areas of supply deficit is becoming ever more important.

What we’re doing about it

With that in mind, we’re investing in two new water transfer mains between our Northcombe and Prewley Water Treatment Works, which will provide strategic links between these key supply sources.

One of the mains will transfer raw water to Northcombe WTW. Currently, Northcombe WTW is solely reliant on Roadford Lake for its raw water supply. The new main provides an additional supply of raw water from Meldon Reservoir and Vellake. This will help share the demand for water across multiple locations and help us protect these water supply sources into the future.

The second main will run in the other direction – from Northcombe WTW to Prewley WTW – and will transfer treated water when demand is higher. Moving water around the network like this will make the water supply more resilient in this area.

With the kind cooperation and generosity from landowners, our contractors and engineering, environmental and planning design teams are currently busy designing the scheme.

This includes a computer model of the regional distribution pipes, so that we can build these new mains in a way that will fully optimise their transfer potential. The design will be finalised in 2023.

Vellake intake image

The work so far

South West Water has been on site since May 2023 to the end of March 2024 and we've laid approximately three quarters of the pipe between Prewley and Northcombe Water Treatment Works (WTW), largely through private land.

We started works on Prewley Moor November 2023 and plan to complete the pipe install through the Common by March 2024, with fencing remaining in place until vegetation within the working areas has re-established.

We are planning to undertake a road crossing at Castle Cross (A3079) from February 2024 for approx. four weeks and works through the A30 underpass (A386) from April 2024 for up to eight weeks; advance warning signs will be in place with the exact start dates.  Both sets of road works will be traffic light-controlled lane closures and we are engaging with Devon Highways (and National Highways in the case of the A30 underpass) to agree appropriate traffic management.

We plan to complete all pipelaying activities across the project by July 2024, with grass reinstatement expected to take approx. 12months. Once the grass has been reinstated, fences will be taken down. Hedgerows will be progressively replanted, and land progressively reseeded, from spring 2024 once access through the affected areas are no longer needed.  A timeline of key activities is below:

  • May 2023: start on site, hedge removals for pipe installation
  • July 2023: easement preparation and pipe installation begins through private land
  • November 2023 – March 2024: pipe installation through Prewley Moor
  • February – March 2024: Castle Cross pipe installation across A3079 (including C road heading north)
  • March – May 2024: pipe installation through A30 underpass (A386)
  • July 2024: pipe installation and initial grass / hedgebank reinstatement complete
  • May 2024: temporary working area (easement) fencing removed following successful grass / hedgebank reinstatement

Green Recovery Initiative

In 2021, we launched our Green Recovery Initiative which focusses on opportunities for us to help the region economically and environmentally. So far, the Initiative has created work across the South West and has allowed us to make environmental contributions that go far beyond our 2020-25 business plan commitments. We also aim for a 10% net gain in biodiversity around our work sites to further enhance the environment in our region.

The installation of these two mains is part of this Initiative. As well as increasing the resilience of the water supply, it is part of our long-term water quality strategy in the North Devon area.