Sewerage pipes at risk of causing pollution to an East Durham waterway are to be upgraded at a cost of £2.5m.
The essential work is due to start next month.
Northumbrian Water’s work at Castle Eden Dene National Nature Reserve near Peterlee, which is owned and managed by Natural England, will involve replacing existing pipework that is currently in poor repair and is at risk from causing pollution into Castle Eden Burn.
Work carried out by contractors Mott MacDonald Bentley (MMB), will protect and retain existing native woodland to help it form an integral part of the more diverse natural environment.
The company is working in partnership with Natural England and its own conservation team regarding the timing of the project, which will start on September 12 and run until May 2017.
The work will involve the removal of trees including non-native conifers planted in the 1970s.
Northumbrian Water said the work is planned to maximise benefits for wildlife, including songbird species such as long tailed tit and chiff chaff and invertebrates such as the rare dingy skipper by reshaping the natural environment.
Sean Barry, Northumbrian Water’s project manager, said: “This project will help to protect the dene and the burn which runs through it, from future risks of pollution.
“As someone who grew up in the area and still lives close to Castle Eden Dene, I know how important the conservation of the site is to residents and visitors, so while this is a delicate project, it will be handled with care and I look forward to leaving the dene ready for the return and resurgence of its natural species.”
A public event for people to find out more about the project will be held at Natural England’s site offices, on Stanhope Chase, Peterlee, on Monday, August 22, 2pm till 7pm at the National Nature Reserve Offices, Oakerside Dene Lodge, Stanhope Chase, Peterlee.
An online community portal at www.nwlcommunityportal.co.uk will also allow people to keep up to date with the work.
The project will require the creation of site entrances and exits from Durham Way, to access the land on the north side of Castle Eden Dene. Northumbrian Water will work with Natural England to restore these, once work is completed.
Chris Evans, senior reserve manager at Natural England, said: “This project is a great example of how Natural England is working in partnership with Northumbrian Water across the North East.
“We will be working closely with their team and are confident there will be real benefits for wildlife on the site once works are complete.”