Relief for home owners in new flood risk study

ASSESSMENT: The crucial section of Masterton said to be at risk according to regional council data released last year which expanded the previous yellow shaded risk area. PHOTO/FILE

Masterton property owners, dismayed to learn last year their homes were under threat of flooding, are now able to breathe a collective sigh of relief.

New data gathered by senior Masterton District Council staff in conjunction with Niwa has come up with an entirely different scenario to floodplain modelling done by Greater Wellington Regional Council.

Huge chunks of Masterton's housing area were declared to be at risk when a flood plain map was made public last year estimated the outcome of a one in a 100-year flood.

The regional council had used aerial photos, surveys, electronic flood mapping tools and analytical techniques to show properties from Akura Road and upper Oxford Street to the Homebush sewage ponds and Lees Pakaraka Road in the south were in the firing line.

The most likely culprit would be the Waipoua River and the height of the stopbanks was called into question.

This week the district council's chief executive Pim Borren reported to councillors on the outcome of new research and data that questioned the regional council's risk assessment.

Mr Borren said Niwa had agreed with research carried out by council staff that flood protection already in place along the Waipoua would not only handle a one in a 100-year flood scenario but could cope with double that.

"It is their view the stop banks would cope with a one in 200-year flood scenario," Mr Borren said.

The newly-released research, along with the Niwa opinion, is to be forwarded to the regional council.

Mr Borren said it was not so much a case of challenging the methodology used by the regional council to arrive at its findings, as it was trying to achieve an agreement on what the real risks were.

Councillor Jonathan Hooker said he understood since the regional council data had been made public last year several projects around Masterton had been "put on hold".

These included housing sub-divisions, he said.

Mr Borren said a legal opinion was now being sought to clarify what flood risk information needed to be included on LIM reports, "given the responsibility we have to property owners and contractors."