The latest moves to find a solution to flooding at State Highway 1 at Hilderthorpe need to be the last, Otago Regional Council chairman Stephen Woodhead says.
''This is State Highway 1. It is an important link and this has been a problem forever,'' he said at a recent committee meeting.
Since 2010, flooding over the main route has become more frequent and in April, heavy rain closed SH1 twice.
In May, the New Zealand Transport Agency (NZTA) started work clearing the flood channels and drains that nearby farmers believed to be impeding the flow of floodwaters.
ORC engineering, hazard and science director Gavin Palmer said last month the regional council, NZTA, Waitaki District Council and Lower Waitaki Irrigation Company agreed a technical group should be formed to ''initially scope an investigation of the issues and possible solutions''.
A representative of each organisation would take part in the group.
Mr Woodhead said the Hilderthorpe problem had come up at least three times in his about 10-year local government career.
''Let's make sure we make progress [this time].''
Dr Palmer said mitigation measures taken in the past had not been as comprehensive as they could have been.
''We aim to take a holistic view across the flood plain. NZTA is optimistic there is a solution.''
Cr Doug Brown said a holistic approach needed to be taken, as any work had been very localised in the past.
''The plains have become very modified by irrigation.''
Cr Trevor Kempton, who is also the Otago Regional Transport Committee chairman, said the transport committee expected NZTA to submit a project for funding next year, as the issue was important for the resilience of the network.
He was ''more confident'' this project would have results because NZTA had made it a primary focus of its work, he said.
''Centre Mile Rd, the detour for when this happens, gets a hell of a thrashing and it is unlikely to be a major cost to alleviate it.''
