SH35 Ūawa River erosion protection work to start in March

Ūawa River scour sites along State Highway 35 will be shored up with a combination of large rocks, rock bags, brush willow and gabion baskets. Photo / NZ Transport Agency

Erosion protection work begins next month to protect State Highway 35 from erosion at Ūawa River.

Transport Rebuild East Coast (Trec), on behalf of NZ Transport Agency Waka Kotahi (NZTA), will undertake the work using a combination of large rocks, rock bags, brush willow and gabion baskets (rock-filled cages).

The site is about 2km north of Tolaga Bay. Work begins on March 9 to repair the scour damage caused there by Cyclone Gabrielle.

“Five sites along a 500m stretch on the eastern side of the river, closest to the state highway, have been affected and require erosion protection work to help protect the riverbank from future damage,” NZTA said in a statement.

“Works will be scheduled around tidal conditions and begin at low tide to ensure safe and suitable working conditions.”

Work will be carried out around low tide, between 4.30am and 4.30pm during the first two weeks.

The remainder of the work from mid-March through April will be carried out between 6.30am and 6.30pm.

While work is underway, traffic will be managed as one site under one-way stop/go traffic management, with traffic lights in place.

“Road users should expect delays of up to five minutes during working hours,” the NZTA statement said.

“Please follow the temporary speed limits and traffic management in place so our crews and road users can stay safe.”

Rock bags are netted bags 2.4m in diameter and 0.6m high, filled with rocks sourced from a local quarry.

Brush-layered willows are live willow cuttings typically 1m to 3m long and installed so the cut end faces the river and the branches extend back into the bank to root and sprout, growing into a living reinforcement system.