The Central Otago District Council's roading and water services teams were busy in the wake of the storm, the council's quarterly report said this month.
The 30mm of rain which fell within 20-30 minutes on March 28 was a one-in-60-years event, according to the Niwa (National Institute of Water and Atmospheric Research) High Intensity Rainfall Design System database, the report said.
Council water services manager Russell Bond said yesterday repairs had to be made after the heavy rain scoured out part of the trail at Alexandra.
That section of trail linked the town to the Millennium Track which was also known as the ''River Track''.
The washout scoured around the old Alexandra bridge piers and the repairs included a retaining wall being built to protect the piers, he said.
A burst water main on Bridge Hill on December 30 caused some damage to the trail in that spot which had yet to be repaired when the thunderstorm hit on March 28, causing more severe damage to the same area, he said.
The repair bill was expected to be about $30,000.
The March storm was very localised and Alexandra's stormwater system was not designed to cope with the volume of water in such a short time, Mr Bond said.
Although the system could not allow for such events, the council could look at how to manage the flooding.
It would carry out a debriefing with the Alexandra Volunteer Fire Brigade, which received 34 calls to properties which were flooded during the thunderstorm.
Council roading manager Julie Muir said the roading crews mostly dealt with scouring caused by the deluge.
The hardest-hit road was Gilligan's Gully but the cost of repairing it was ''insignificant'', she said.
