Sediment and silt spilled from the subdivision into the creek for the seventh time in 18 months during heavy rain on Tuesday last week.
Fish and Game officer Paul van Klink described the stormwater management in the subdivision as ``woefully inadequate to deal with any rainfall event, never mind a big one''.
The announcement to postpone the boardwalk opening came from the Wanaka Residents Association (WRA) and Fish and Game, on Tuesday.
In a statement, Otago Fish and Game Council chief executive Ian Hadland said the opening now would be "closer to spring''.
The $100,000 boardwalk has been a main project for the Wanaka Residents Association (WRA) for more than a year and president Roger Gardiner said the WRA was "very disappointed'' at having to postpone the opening. But he said until the Queenstown Lakes District Council (QLDC) took decisive action to prevent another spill from happening, the walk would remain closed.
The stormwater drainage catchment was on council land, Mr Gardiner said, and it was up to the council to find a solution.
His message was clear.
"You own this land. This is happening from your land into here [Bullock Creek]. You've got to fix it.''
In response, QLDC chief executive Mike Theelan said the issue was far more complicated than what was outlined by the WRA.
After the Alpha Series detention system was overwhelmed in a storm earlier this year, changes were made to the system, including extended stormwater ponds and diversion channels, Mr Theelan said.
However, saturated ground from heavy rain last Tuesday meant the detention systems failed again, which was "very disappointing for all parties''.
Mr Theelan said the council's expectation was that urban development would not lead to increased runoff. However, he said the low-impact stormwater design the council was committed to was more sensitive to weather variability.
"The Bullock Creek area has traditionally been fed by a mixture of springs, rainwater, subsurface and overland flow, and the intention is to stabilise the area back to these levels. One of the challenges is managing those outcomes during the phases of land development, where temporary solutions are in place and often large amounts of soil are exposed. We do work with all developers to mitigate these effects but it is an ongoing dialogue and there is a need to update the plans as development proceeds.''
"It's disappointing that the WRA has chosen to apportion all the blame to QLDC, when there are multiple factors that have led to this postponement decision. QLDC welcomes the opportunity to maintain an open and frank, direct dialogue with WRA and Fish & Game whilst we work with developers and undertake our own reviews to reach the best outcome all round.''
But Mr Gardiner believed the problem required "much further action than more meetings and plan updates'' and said, to date, no progress had been made in discussions with QLDC staff.
