The NZ Transport Agency (NZTA) started work today (Monday 16 April) to improve flood protection for the Waitaki Bridge on State Highway 1 (SH1) near Oamaru.
NZ Transport Agency Acting Otago/Southland State Highways Manager Ian Duncan says the work is to stop a major river channel causing further erosion of a river bank just upstream from the bridge.
This channel will be directed away from the bank and into the middle of the river. This will be done by building four separate rock groynes extending up to 25 metres at right angles from the river bank. About 2,000 tonne of rock is needed to build these.
“If the groynes are not built now, the continuing erosion of this river bank could threaten the northern bridge abutment, making it more vulnerable to flooding. Two groynes are being built now and the remaining two in October after the peak salmon spawning and incubation season.”
Mr Duncan says the work costing $150,000 is expected to take less than two weeks to complete and is part of the NZ Transport Agency’s management of a bridge that is a vital link in the SH 1 network. The contractor is accessing the work site through a rest area at the north end of the bridge. Signs are in place warning motorists where trucks working on this project will be turning on-and-off SH1 in this location.
The resource consents granted by Environment Canterbury Regional Council and Waimate District Council for this work did not require public notification.