Mr Stewart has collated for the Dunedin City Council rainfall data from around the city from the week-long event in late May.
"It was unusual in nature in how long it lasted ... but, generally, as a rainstorm it wasn't anything startling."
The event was nothing like the 2006 rainstorm, which was more intense. .
In 2006, rainfall intensities were as high as 18mm an hour, whereas in May the highest was 14mm an hour at Sullivans dam.
May's event was also unusual for the second burst of rain coming about five days after the start of the rainfall.
"While not nearly as big, everything was saturated and the rivers were still up."
The return periods for the event highlighted this, he said.
There was a "huge contrast" in rain on the hills compared with lower parts of the city - Pine Hill received 300mm, compared with Musselburgh's 140mm.
The return period for Sullivans dam for a one-day event was 11 years compared with Musselburgh's two years.
"For a lot of the city's lower sites, it wasn't a significant event at all."
The event was typical of a northeast rainstorm with a "variable" effect across the city, he said.
In the "lull" between the two events, it snowed on top of Swampy Summit, which showed how much the temperature dropped.
"It was a more unusual event at altitude."
While predictions indicated the area could get rainfalls in the magnitude of the 1980s flood, it did not happen, although there was probably more rainfall in 1980.
May's event was over a longer time, he said.
"There was still enough rain to flood the Taieri but not like the devastating flood of the intensity [of other more recent events]."
Dunedin City Council water and waste services manager John Mackie said the rainfall data would be incorporated into a much larger report on the May floods that would be presented to next month's infrastructure services meeting.
The data showed the rainfall varied throughout the city, but overall about 400mm fell during the week-long event.
However, the city was lucky the flooding did not seriously affect any built-up areas, he said.
