📋 Tender Overview
Rock armour will be built to protect a stretch of Otago shoreline where State Highway 1 is threatened by coastal erosion, in a new 3 million project.
With funding approved, New Zealand Transport Agency Waka Kotahi (NZTA) is preparing to start work next week to improve the resilience of part of a 7km section of SH1 in North Otago that runs between the Main Trunk rail line and the coast. Parts of this section of highway are continuing to erode and targeted rock armouring will be installed where needed.
Rock armouring involves placing large rocks along the shoreline to absorb wave energy and reduce erosion, helping protect the highway from damage (see image below). Grant Hood Contracting has been appointed to deliver this latest project and is due to have crews setting up from Monday (22 June) at Kaitiki Beach, between Palmerston and Hampden.
Parts of this highway have been vulnerable to coastal erosion for decades, says NZTA senior project manager Jason Forbes.
Protection structures were first built in the 1970s, and weve continued to monitor and respond to changes along the coastline since then. Because the highway is constrained between the railway and the ocean, moving the road inland would be extremely expensive and disruptive. Strengthening the coastline with rock armouring is the most practical and cost-effective option.
In 2017, three high-risk coastal sites in this area were armoured, and a further 10 sites have been completed since then.
Most of Katiki Beach will eventually require some level of protection to ensure SH1 remains resilient. This is a critical freight and lifeline route between Dunedin and Christchurch, so maintaining its reliability is a priority for NZTA, Mr Forbes says.
The new project will continue work underway in recent years, targeting high-risk sections of coastline between Shag Point Road and approximately 300 metres south of Squire Road.
Rock is being crushed and stockpiled offsite in anticipation of the work and the contractors will set up a site office and material storage at the beachs northern rest area/truck stop (illustrated in image below).
The rest area will remain open for freight operators and others, but there will be single lane access through the site, entry from the north and exit from the south, with limited truck parking retained in the southern section. Temporary traffic management will be in place to ensure safe access in and out of the rest area.
As work progresses, the southernmost rest area (also illustrated below) will also be used for construction activities and is expected to be closed to the public from late July or early August, until completion. The work is dependent on weather and tidal activity, but project completion is expected within 12 months.
