On the southern side of the toilet block some itinerants had constructed a makeshift camping area that also appears to have been used as a drug injection site.

There was also documentation left behind at the site that identifies individuals who may have been responsible for it.

One of the documents was a custody management record from Bathurst police.

The site was discovered by a regular walker in the area whose dogs refused to come when called.

The man asked not to be named for fear of reprisals.

"I let my dogs out for a run and I noticed they were up around the old amenities block sniffing around," he said.

"When I called they didn't want to move so I walked up and saw the mess.

"I had a quick look in the tent to make sure their wasn't someone passed away inside as it kind of looked like a deserted camp site."

The dam is owned and operated by WaterNSW however the recreation area is maintained by Blayney Shire Council.

Council general manager Rebecca Ryan said that they had become aware of the problem late last week thanks to an email from the resident.

"Our ranger inspected the site and arranged for Council staff to remove the rubbish with appropriate plant and dispose of it," she said.

"Our investigation on who illegally dumped their rubbish remains ongoing."