Upgrade planned for flood-prone Tauranga area

This woman was labelled a hero after squeezing herself into a flooded drain to free debris and save businesses in Burrows St from being flooded out. Photo/file

Stormwater catch pits are proposed to be upgraded in Burrows St to reduce the likelihood of further overflows when Tauranga was hit by torrential downpours.

Council's drainage services team leader Wally Potts was responding to the dramatic events at the bottom of 15th Ave during Monday night's flash flooding that averted serious flooding to neighbouring commercial buildings.

The water was only 10mm away from entering Belvedere Construction's building in Burrows St when a woman who called herself Lucy squeezed into a flooded roadside drain pit and cleared the debris - allowing the water to drain away.

Potts said the council was proposing to improve the catch pits to make them less prone to blocking and more efficient in getting water into the pipes.

''We are not proposing to upgrade the pipes.''

He was responding to questions from the Bay of Plenty Times about whether the council planned to improve the Burrows St stormwater drainage system and the other system around Fraser Cove's Brook St that failed to cope because the storm coincided with high tide and the water was unable to freely get away.

Potts said there were no plans to upgrade the pipe capacity because the velocity and depth of flood flows were not enough to threaten public safety by sweeping someone off their feet.

He was referring to the council's decision in 2015 to give the highest priority to people's safety. The council's policy was that its level of service for stormwater was to not provide for a reduction in the risk of flood damage to buildings or changing climate conditions. Neither did it address the risk of flooding from rivers or streams. Residential private property took priority.

Belvedere Construction managing director Trevor Wilkinson was unimpressed with the statement, saying nothing had changed.

''It's nothing new. He said that several years ago when we had our last meeting.''

Wilkinson said the council had a duty of care to do everything reasonably practical to eliminate the risk to property as well as lives.

Potts also commented on the council's response to the thunderstorm watch issued by the MetService on Monday for the north-eastern part of the North Island.

He said that during the afternoon and early evening, council staff monitoring MetService software estimated Tauranga would only receive 4mm of rain from 7-8pm and a further 7mm from 8-9pm.

However, MetService then issued a thunderstorm warning at 7.30pm for Tauranga based on live radar. He said this meant the storm was already under way and there was a higher risk of intense rainfall.

''We do not get the opportunity to pre-clear drains or ponding hotspots. Our contractor had started heavy rain inspections prior to Monday's storm but had only partially got through these.

''During the storm, our contractor was very active in responding to areas where flooding was occurring.''

Potts repeated his warning that it was never safe to enter drains in storm conditions because when a drain suddenly cleared it created suction that pulled anything in the drain inward.

Tauranga's stormwater system
- 583km of stormwater mains
- 5 pump stations
- 250ha of ponds and wetlands
- 61km of identified overland flow paths