An industrial subdivision that was allowed to be built on a flood plain at Windermere will end up costing Tauranga ratepayers up to $1.6 million.
Repeated flooding of the Roxanne Place subdivision has resulted in the council agreeing to a plan to control floodwaters that hit the cul-de-sac, which runs off the end of Poike Rd.
It comes hard on the heels of another million dollar bailout by ratepayers of a council property deal, in which it was forced to pay $10 million towards the purchase of a 170-hectare farm at Papamoa East in 2007.
The Windermere planning decision to allow the subdivision to be built at the bottom of very large catchments drew a hostile reaction from a council meeting this week.
"How come they were allowed to build there? It would have been obvious that it was going to flood," Councillor Bill Faulkner said.
Council drainage services manager Graeme Dohnt did not attempt to justify the 2005 planning decision, except to say that the outcome was that the developer, Oropi Park Ltd, was allowed to do it.
Confirming councillors' suspicions, he said: "You would not want to build on a flood plain."
Councillor David Stewart said that if the council received professional advice prior to approving the subdivision, then perhaps the accountability lay somewhere else.
Deputy chief executive Christine Jones said an assessment would have been carried out at the time.
The vulnerability of the subdivision to flooding was highlighted during the storm of January 2011, when water poured through Storage King at the bottom of Roxanne Place.
It led to the construction of a bund wall where the rear of the property adjoins the Waimapu River.
Mr Dohnt said the wall had prevented further flooding of the property.
And while the council records showed that flood waters had only entered the grounds of one other property, Lollipops, a survey last month of 10 businesses threw up a different scenario.
They said the frequency of flooding had escalated in the past two years, with flood waters entering six properties and two buildings. One businesses reported stock losses of $500,000 from last November's storm.
Mr Dohnt said everyone reported a high level of frustration at the increasing frequency of floods and the impacts on their businesses.
The common problem was the recurring issue of flood waters at the Poike Rd end of Roxanne Place preventing access to the subdivision.
The depth exceeded 400-500mm and during the January 2011 storm reached 1.1m.
The survey also revealed that flood waters had on occasions extended up Roxanne Place to the head of the cul-de-sac.
Combating the flood waters will be tackled in two stages, starting with $590,000 next year to raise the level of Poike Rd for 250 metres up to the intersection with Roxanne Place, and doubling the size of the stormwater pipe along Poike Rd. This would give all-weather access to the subdivision.
However, with the council's stormwater budgets tied up for the next few years on projects in the Mount Maunganui industrial area and Arataki's Eversham Rd, the next $1 million stage of works would not begin until 2017.
This will include a berm around all Roxanne Place properties, a pump station and floodgates, upsizing the existing Poike Rd culvert and increasing the storage capacity of the dual open drain.
The $1.6 million scheme will mean reprioritising other stormwater protection projects in the council's 2012-22 plan.