Wardens at Ogden Water Nature Reserve revealed the ongoing problems by spray painting the dog mess that is being left on footpaths and other areas of the reserve.
Due to the rising complaints, coupled with the holidays coming up and the leaves falling hiding the piles for unsuspecting feet to tread staff have taken the action of spray painting the piles of poo left on the woodland trail from the car park to Ogden Clough and the reservoir trail from picnic area to woodland trail entrance.
Wardens on the site are making a plea to owners to make sure they clean up after their pets and use to dog waste bins on site.
A spokesperson said: "We have recently seen an increase in the number of piles of dog poo that have been left and not cleared up.
"This is only a very small minority of the dog walkers who visit here, most are responsible with their dog’s waste, picking up, bagging and placing in the bins.
"To those responsible owners we can only say thank you, not only do you help keep the place clean but many of you are the eyes and ears reporting issues and problems when you visit.
"But there are a small minority of irresponsible dog owners.
"We have to say that after using two full cans of spray paint it was a horrid thing to look back and see how many pile spots were on the sides of the trails, in fact we lost count. But hopefully this will help people visiting avoid the piles and remind those who do not pick up to do so.
"Not only is it the sight that is unpleasant, but there is the possibility of disease transmission to other dogs of any with illness, people getting it stuck on boots or even worse pram or wheelchair wheels and thedetrimental effect to the wildlife and flora of the nature reserve.
"It is the responsibility of the dog walkers here to pick up, bag and dispose of the dog poo when visiting.
"We provide the bins and empty on a regular basis.
"There will also be regular patrols at different times by the safety wardens to check people have dog bags and issue fines if required – hopefully this will not be needed as the pink poo piles will show what an issue this is and shame people into picking up."