The Queenstown Lakes District Council has deferred for another year a project to stop wastewater entering the Shotover River so it can look for more affordable solutions.
The proposed $42 million wastewater and sewerage facility on the Shotover Delta, designed to end the discharge of treated wastewater into the river, was given Environment Court approval last May.
However, following analysis of wastewater flow data from the past two years, council last month deferred development from 2013 to allow further investigation before the April 22, 2014 consent deadline.
QLDC strategic project manager Martin O'Malley said the original 2007 plans were based on "extremely conservative" modelling, and since then, more accurate data measuring the actual flows had been collected.
"When we looked at the more accurate info, it had reduced by about a third ... it had reduced from about 16,000cu m a day down to 11,000cu m a day."
Deferring the project meant the council could look at alternatives in light of the decreased wastewater projections.
"Before we go ahead with the original plan we want to make sure we are not overlooking some more cost-effective solutions." To prevent erosion of the project's waste-water disposal fields, and minimise the risk of site flooding that could lead to pollution entering the Kawarau and Shotover Rivers, a stone or rock-reinforced revetment line is to be constructed.
A QLDC infrastructure service committee will decide today on the priority of funding for the construction of the 800m long structure, which is estimated to cost $920,000.
Mr O'Malley presented two options - for the council to carry out the construction when needed, or make a submission to the 2011-12 draft annual plan to include funding of $676,000 as a contribution to a joint approach with the Otago Regional Council on the flood protection works.
The second option was recommended so the QLDC could contribute to the ORC's design, construction and supervision of the revetment line without the design and maintenance risk lying with the QLDC.
The ORC will build a flood protection training line worth $1,075,000 to direct the flow of the Shotover River towards the river's true left bank.
