VANCOUVER - Vancouver's police department is calling on the city to curb the massive outdoor viewing parties that swelled with every Stanley Cup playoff game, boiling over after the Vancouver Canucks' loss and descending into a destructive riot.

An internal review released by the force Tuesday recommends changes to ensure festival-style public gatherings leave police with some way to keep the size of the crowds under control and keep alcohol out, particularly those events that encourage booze-fuelled youth to congregate in one spot.

Three separate reports released since last week have narrowed in on the more than 150,000 people who came downtown, including roughly 55,000 people watching giant screens inside a loosely fenced-off celebration site, and the prevalence of alcohol among the revellers.

As the Canucks played Game 7 of the Stanley Cup final on June 15, there was no way to stop the constant flood of fans heading downtown looking for a party or to keep them away from the celebration site once they arrived, says the police report.

"Do not have large scale public events with 'festival seating/standing' that concentrate large crowds of young persons — particularly the young 'hooligan' demographic — who have the propensity for public drinking in a small area," says the report.

"This creates problems in the crowds both inside and outside, especially when the entertainment is visible outside the venue."

Police Chief Jim Chu said the force isn't suggesting the city stop holding public celebrations altogether, but he said the next big event can't look the same as the Stanley Cup playoffs.

"I think there are many opportunities to do public-space events, depending on what kind of event it is," Chu told reporters after the report was presented to the city's police board.

"On city streets, when it's a public space, we have to find a way to control the size of that crowd."

That could include holding such events at an indoor venue, such as B.C. Place stadium, where organizers could tightly control how many people attended and what they brought in with them, said Chu.

Such events could also require tickets to attend, and the city's transit system could stop shuttling fans downtown when crowds become too large, he said.

As the Canucks advanced through the Stanley Cup playoffs, the city closed off several streets and set up large screens at a central celebration site to allow fans to watch the games.

By Game 7, tens of thousands of fans were inside the celebration site, far exceeding anyone's expectations. The crowds were so large that the grated fencing lining the perimeter of the site had to come down.

It was inside the celebration site that the first car was set on fire, setting off a riot that lasted more than four hours and caused millions of dollars over several blocks.

Once the city decided to set up the so-called live site, Vancouver police asked municipal staff to require tickets for spectators, but the idea was rejected.

Mayor Gregor Robertson said it wasn't feasible to set up a ticketing system on such short notice.

Robertson agreed that changes need to be made to better control future events, although he made it clear the city plans to continue holding public celebrations — including during this November's Grey Cup game in Vancouver and the next time the Canucks reach the playoffs.

"I think we needed to have activities downtown for people, people are going to come downtown," Robertson told reporters.

"The difficulty in actually keeping the live sites secure, the fencing, the size there and the number of screens, we're going to have to do it differently, there's no question about that."

Robertson didn't say what specific changes may be put into place.

The police report also gave the force high marks for their preparation and planning in advance of the playoffs, and again insisted there was no way anyone could have known trouble was brewing downtown.

Chu has conceded there weren't enough officers on the streets, while also arguing that adding more officers wouldn't have prevented the riot.

He has also suggested that any mistakes were minor and didn't affect the outcome that night.

"Despite some glitches, our plan worked and worked well," said Chu.

The police report's other recommendations include:

— Police forces throughout the region should receive better training and equipment to prepare for large events and better co-ordinate their response.

— Police should have priority access on local cellphone networks so they can communicate even when the system is jammed. Further, the CRTC, the federal body that regulates telecommunications, should require mobile providers to provide police with such access.

— Liquor fines should be increased.

— The city should increase the force's operating budget so more officers can receive riot training.

— The province should create a special designation for "regional events," which would trigger provincial funding and bring together resources neighbouring police forces.