Construction techniques

We will install pipes following good industry practice using tried and tested 
techniques. The most-used method to lay pipe is an open cut trench. 

Where we need to minimise disruption to the surface – such as when we want to 
cross major roads, rivers, and railway lines – we will use trenchless techniques. 

Our working area will be up to 40 metres wide, but will be narrower for crossing 
sensitive hedgerows, tree lines and watercourses and up to 60 metres wide in 
areas where there is peat.

Open cut trenching

There will be parts of the pipeline where we will have to use traditional methods. 
Open cut trenching is when a trench is dug open by a digger, the pipe is laid and then 
covered over. 

Trenchless techniques

Where we need to minimise disruption to the surface - such as when we want to cross 
major roads, rivers, and railway lines - we will use trenchless techniques.

Trenchless techniques will be used to lay the pipe underneath main rivers and roads. This 
involves directionally drilling or auger boring, where a machine will drill or bore a hole 
through the ground from one side of an obstruction to the other. The pipe is then pulled 
through the hole.

Post-construction

We need to test the pipeline before it’s used to supply drinking water. This is 
called the ‘commissioning phase’. 

During this phase we will pressure test for leaks and ensure the pipeline is clean. 
Water samples are taken and tested to make sure the water is safe to drink. 

Once the water and the pipeline pass all the tests, we will reinstate land or 
habitats, such as planting new hedgerows, reinstating topsoil and reseeding 
grassland. Where possible, we will reinstate land and habitat earlier.