The ED treated 50 revellers on the day, and between 10 and 20 the following day, process improvement manager Allan Cumming said.
Mr Cumming said the department had been well prepared for the influx of patients, most of whom had minor injuries.
The extra patient load on March 24 and 25 was one reason the department treated or transferred 86.8% of patients within six hours, a report to today's hospitals' advisory committee said.
The target is 95%, and improving ED wait times is the aim of a major internal improvement project entitled "6 Hours - It Matters!" to address some of the worst wait times in the country.
While Dunedin's ED was still performing better than in previous quarters, the result was a deterioration from 88.1% in February and 89.3% in January.
Construction work on the new observation unit, higher overall patient numbers, and the generator installation, also contributed to higher waiting times, a report said.
The Dunedin ED had 3674 patient attendances in March, compared with 3440 in March last year.
In Southland, 92.6% of ED patients were treated or transferred in six hours in March (February 87.9%).
