The river Ehen was designated a
Special Area of Conservation in 2005. The section of the coast into which it flows was designated as the
Cumbria Coast Marine Conservation Zone in 2013. The Ehen is home to the
Ennerdale black pearl, a rare black
pearl formed in
freshwater pearl mussels. It is the only river in England to be part of the project "Pearls in Peril", funded by the European Union's
LIFE + NATURE Programme. The project aims to conserve the species at 21 sites in the UK. The freshwater pearl mussel relies for part of its life on the presence of salmonids, a group of fish including salmon and trout. Sellafield has previously used water from the River Ehen for cooling on the site, but ceased this operation in the 1990s. There is a weir on Ennerdale Water, and as at 2016 the valley continues to be an important source of drinking water for customers of
United Utilities in West Cumbria. However, there are plans to supply these customers using a new pipeline from
Thirlmere because the
Environment Agency has confirmed that for environmental reasons it will rescind the abstraction licence for Ennerdale. This means United Utilities must stop using it as a source of water by 2025 at the latest, and therefore will need to find one or more alternative sources of water. ==References==