A £500,000 project to improve the quality of the River Rede – one of the only rivers in England with a significant population of fresh water pearl mussels – is under way.

Northumbrian Water has been working with the Environment Agency, to understand how it can clean its 27-mile Rede pipeline, without impacting on water quality in the river.

The pipeline, which carries untreated water from Catcleugh Reservoir near Byrness, has been delivering water to Whittle Dene Reservoir near Harlow Hill for more than 100 years.

The pipe gets cleaned once every year, over a 24-hour period to stop harmless sediment building up in it. This new project will help address a historical practice of sediment-laden water being flushed into the River Rede during the cleaning process.

The water company is changing the valves at various intervals along the pipeline, so that any water escaping from the pipe during the cleaning process, will be on to land, helping to protect the quality of the river.

In four locations, where water will still enter the river, silt bags will be used to filter out the sediment, as well as slowing down the speed of the water and prevent it from eroding the river banks.

Northumbrian Water’s Project Manager, Chris Bond, said: “It’s really important that we maintain and clean this pipeline to make sure that our customers continue to receive great tasting tap water well into the future.

“We’ve been working closely with the Environment Agency to understand how to make changes to the valves along the pipeline, so that when we do clean it, we can help to protect the quality of the River Rede.

“As a result, we will be modifying 13 valves along the 27-mile pipeline, as well as constructing two new valves. This won’t affect customers’ water supply and as most of these changes are in rural land, customers shouldn’t see much activity.”

Work is expected to be completed by Friday, August 23.