Police arrested a man on suspicion of possessing the class B- drugs cannabis and ketamine on the first night of stepping up patrols in Coopers Meadow.
The increased patrols come as a result of reports of youths drinking and drugs being used in the area.
In July, Marlborough town councillors spoke of their concern over drink and drugs parties in the Priory Gardens, in view of the residents of The Priory old people’s flats.
The problem has now moved to Coopers Meadow, between Town Mill and George Lane.
It is just 200 yards from the police station in George Lane and an area has been fenced off by Action for the River Kennet to allow cows to graze to encourage wildflower growth.
At the back of the grazing area a grass strip has provided an almost hidden area where groups of young people have been gathering, leaving evidence of their drinking and drug taking.
Police acted after newly-elected town councillor Val Compton, who litter-picks at Coopers Meadow every day, reported the presence of bottles and cans that had contained alcohol and small plastic sachets possibly used for drugs.
PC Jeremy Bachelor said PCSO Jonathan Mills discovered a 21-year-old Swindon man in possession of the suspected drugs on Monday night.
“We are aware there is a problem with anti-social behaviour in Coopers Meadow on the grass strip along the stream and we will be patrolling it quite heavily,” said PC Batchelor.
“We had only just stepped up patrols when, on the first night, PCSO Mills came across this man in his early 20s who was clearly under the influence of something.
“A search revealed he had small quantities of cannabis and ketamine (a drugs used to tranquilise horses) and he was arrested by a response officer from Swindon who was called by PCSO Mills.”
However, because of the small quantities of drugs found on the man, which he said were for his personal use, he was later released with a caution.
Police are also concerned after vandals cut a section of the wire fence around the grazing area and stretched it across the grass path which is frequently used by local dog walkers. PC Bachelor said that this could have resulted in injury if somebody had tripped over it and fallen.
Coun Compton said she went to the police after noticing a growing number of discarded drinks containers during her daily litter picking in Coopers Meadow. “I noticed an increasing number of alcohol receptacles and I was also finding little polythene bags that could have had suspicious substances in them,” she said.
She said she was reluctant to highlight the problem in case it made the problem worse.