Conditions have been placed on a Flintshire pub's licence after police found children as young as 14 attending events.
Councillors were told of an "entrenched culture" of underage drinking at the Albion Hotel, Connah's Quay.
Police wanted a ban on functions aimed at students, but Flintshire's licensing sub committee said events after 1900 should be notified to officers instead.
Incidents included a brawl involving up to 150 in the pub car park.
The pub must also install CCTV with recordings kept for 28 days and available for inspection.
In a report to the council, North Wales Police said they had been called to the pub in the town on several occasions since September to deal with incidents of disorder and underage drinking.
On 29 November, the force control room recorded one police constable reporting: "One (pepper) sprayed, fighting breaking out all over."
Another officer on the scene warned: "We are outnumbered - 150 people here."
Police teams from as far away as Wrexham had to be deployed to the area surrounding the Albion Hotel to restore order.
The pub was visited by police the next day and the landlord advised to cancel further sixth-form events at the premises, councillors have been told.
But 12 days later, police had to return to the pub where about 100 people had gathered outside, and fighting again broke out.
In their report to the council, North Wales Police said several teenage girls aged from 14 to 17 admitted they had got drunk in the pub.
"Several 15-year-old females were conveyed by police officers to either their home address or to taxi ranks," said police.
The police asked the council to impose a number of restrictions on the pub, including a complete ban on sixth-form and school-leaving parties, and any event for those under 21, along with other restrictions.
However, after the meeting, a Flintshire council spokesman said as there had been no further complaints since the incident on 10 December, the committee decided to impose a number of conditions rather than putting a stop to events.
These include a colour CCTV system to be installed and maintained, with recordings kept for 28 days and available for inspection by police and council officials.
Also, any evening or night-time event held after 1900 has to be notified to police. This condition will be in place for 12 months.