Senior Sergeant Trevor Thomson said three arrests could be directly attributed to the event, although the street party's flow-on effects could have resulted in more.
The arrests were all for minor offences, he said.
While the atmosphere was "very good", police were disappointed by the number of drunks at the party.
Numbers peaked at 1200 to 1400 party-goers between 4pm and 5pm, Snr Sgt Thomson said.
By about 7pm, most of the party-goers had dispersed with the rain, he said.
Just before 11pm, the fire service doused a burning couch on Hyde St, a Fire Service spokesman said.
Otago University Students' Association president Harriet Geoghegan said the party was well organised, with a strong police presence and little bad behaviour.
"Everyone had a good time - there was no trouble that I saw."
Snr Sgt Steve Aitken said all up about 25 people were arrested for street offences on Saturday and yesterday morning, in a "steady" night for police.
