Sentencing John Larsen at Caernarfon Crown Court, the judge said: "If you hadn't been arrested, I'm entirely satisfied you would have killed someone or caused serious injury."
Merfyn Hughes QC said the former mayor of Denbigh had abused the trust of local people, and cared nothing for vulnerable residents living nearby.
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Rain clipping the far north through the evening but elsewhere staying dry with some sunny spells.
Public Health Wales figures show 25 more cases of the virus have also been confirmed.
Photos taken on Saturday morning show Roald Dahl Plass strewn with empty beer bottles and discarded canisters of laughing gas.