Beauty spots in Bradford are being spoiled by the “senseless behaviour” of dog owners who are hanging bags filled with their pet’s excrement from tree branches, Yorkshire Water has warned.

The Bradford-based water company said millions of pounds have been spent opening up its sites, which are being ruined by irresponsible dog owners who fail to clean up after their dogs.

The company said it removed tonnes of dog mess from its 120 recreational sites – even though most boast several dog bins – including sites in Bradford such as Chellow Dene, Thornton Moor, Doe Park and Hewenden.

And it is becoming increasingly concerned with a few dog owners who have been hanging bags of dog mess from tree branches at its sites, despite the company also giving away free dog mess bags as well as organising regular visits by council wardens, who are able to fine anyone not clearing up after their dog.

Geoff Lomas, recreation and catchment manager for Yorkshire Water, said: “We’ve spent millions opening up some of our stunning reservoir sites, with thousands of people using them every week for their enjoyment, whether it be for exercise or to simply take advantage of some of the incredible vistas, flora and fauna they have to offer.

“So it’s very sad that despite our best efforts, we’re hearing reports that people are having to spend more time watching where they’re walking rather than taking in some of the incredible views on offer.

“Not only does such irresponsible behaviour make it harder for everyone else to enjoy our beautiful sites, but it’s also very unpleasant for the people who have to clear it up.

“Our message to them is simple: Please do the right thing and make sure you always clean up after your dog and dispose of any mess in the correct way.”

Yorkshire Water said there has already been more than a dozen occasions where company wardens have had to clear areas of some sites which have been carpeted in dog muck.

With the school half-term holidays looming and the warm weather, the company has also encouraged people to visit the recreation area of its website – yorkshirewater.com/recreation – to find all sorts of ideas for walks and other outdoor activities in and around the district.