Tauranga City Council is looking at buying up two flood prone properties at Oropi and Pyes Pa.

The recommendation was passed with little discussion at the council last meeting.

'We have in some respects allowed people to subdivide and build in floodable areas, just as we allowed people in years past to build in areas susceptible to tsunami,” says Councillor Steve Morris.

'While we have no legal obligation, I do believe we have a moral obligation.”

Gail McIntosh says it's not just the flood damage. The Matua people living on flood prone properties were subject to ongoing stress and strain, living with the uncertainty that a flood may occur.

The two flood prone properties are in the Waimapu and Kopurererua catchments. From agenda maps, one property appears to be in the vicinity of Pengary Lane Pyes Pa, the other near Oropi Road south of the highway.

The price offered is being kept confidential.

Both properties are subject to significant depth and velocity flood risk, but as the risk is flooding by nearby streams or rivers, the council doesn't have to intervene.

City council staff consider the flood risk is too great not to act. Given the magnitude and nature of flooding at these locations, no other mitigation solution, aside from property purchase, is considered to effectively mitigate this risk.

Under the Level of Service, at risk properties are those where a depth x velocity threshold of ≥0.4m2/s is exceeded within 8m of a building with a habitable floor for residential and rural residential zoned private property, and ≥0.6m2/s for non-residential and non-rural residential zoned private property.

The 0.4m2/s threshold was established by TCC as the trigger for intervention for residential and rural residential zoned private property as this flow presents a significant hazard to life for children. A 0.6m2/s threshold represents an extreme hazard for children and a moderate hazard to adults – for this reason it was considered a more appropriate threshold for non-residential and non-rural residential zoned property - industrial and commercial areas.

To support Council's approach to flood risk management, funding of $10.5M / annum for the first three years of the 2015-2025 LTP was confirmed. This comprises:

$7.1M in year one, $8.2M in years two and three, and $6M in each of years four to ten for capital works

$1.4M in year 1 and $0.3M in years tow to ten to implement the programme of 2D hydraulic modelling; and, $2M for years one to ten through the Stormwater Reactive Reserve Fund to provide for relief support to flood affected landowners following floods that damage buildings and property.

Staff identify flood prone properties through the council's 2D hydraulic modelling programme. Council will intervene on properties with a documented history of flooding of more than once in the past ten years.