Revellers left a beauty spot covered in gas canisters, beer bottles, cans, plastic, cardboard and other rubbish after gathering to party on Friday night.
Hundreds of revellers were found enjoying the hottest day of the year at Woodchester Park near Stroud yesterday evening.
Some were swimming the water and others had lit fires. There was also litter strewn around the area.
An angry angler saw the scene unfold on lake 1, and he now fears environmental damage is likely to affect fish and other wildlife, he said: ” It was horrendous, gas canisters and beer bottles were thrown in the lakes and suncream and fake tan is now leaving the water in an awful state and impacting fish and birds that have just reproduced.”
A clean-up operation was in place this morning with national trust and anglers helping clear the debris.