Despite efforts to keep the trails along the Don River clean, some people continue to vandalize and treat the area as their own personal dumping ground.

For city officials – and residents seeking a picturesque spot for a hike, run or bike ride – the situation along the Don can be both worrisome and aggravating.

"I really wish they would clean up the graffiti," says hiker Colleen Orticello.

Susan Mackinnon says the Don Valley can be a great escape from the rigors of everyday life in the big city.

But she agrees there are some spots where the Don's scenic beauty is being ruined by urban filth.

"There's patches of, like, garbage bags and mattresses … and all sorts of debris," on the side of the river, said Mackinnon, who walks the trails several times a week.

Graham Harding, of Toronto water infrastructure management, says officials have gone to great measures to fix problems like sewage overflows that at one time emptied into the river.

Those projects have improved the area greatly over the last decade.

Still, stopping people from dumping and vandalizing has proven to be an uphill battle, he said.

"That should be reported and then it will be dealt with by bylaw officers," Harding said.

One of the ways the city is trying to prevent these kinds of problems is by educating people about the importance of conservation, Harding said.