The Hills Council ignored not only the advice of the NSW Police Force but also its own officers when it approved a bigger nightclub capacity — 590, up from 412 — for The Hillside Hotel.
Until last week's council meeting, the hotel had been operating its downstairs nightclub without development consent from the council.
"What you will see if you increase the patronage, in our opinion, is an increase in violence," Hills crime manager Detective Inspector Gary Bailey said.
He presented a crime map to councillors that showed The Hillside Hotel fell within a 600-metre hot spot radius.
"Over a 12-month period there were 27 calls to the hotel," Inspector Bailey said.
He was concerned his sergeants were already regularly attending alcohol-related incidents at the McDonald's near Hillside on Thursday and Friday nights, when the nightclub is open.
He said he had no complaints about management at Hillside but police did attend Castle Hill RSL for far fewer alcohol violence incidents. He attributed this to the closure of the RSL's nightclub.
Patrick Hurley of PGH Environmental Planning said Hillside could cater for 900 patrons, and still comply with the Building Code of Australia.
But a report by council's senior town planner, Shannon Butler, said the hotel needed 25 extra parking spaces to be compliant if a patron limit of 412 were applied.
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The council has approved the increase in patron numbers subject to conditions, including a one-year trial but not an increase in parking.