SH2 Watchman Road Intersection
The Watchman Road Intersection Project was designed to improve safety at one of the most dangerous intersections in New Zealand, create an iconic gateway for visitors heading to the Hawke’s Bay Region whilst preserving and enhancing a wetland area.
A community Open Day was held on the 16 September 2018 with the road officially opened to the public on the 17 September 2018.
The main works involved constructing
- a new at-grade roundabout at the Watchman Road, at Meeanee Quay and SH2 Intersection,
- upgrade the Watchman Road Causeway and
- install upgraded infrastructure including a cycleway and utility services.
The Watchman Road causeway bisects the Ahuriri estuary which is located within the Westshore Wildlife Reserve, a delicate natural habitat which is classified as a wetland of national and ecological significance. A major section of the project was the widened and strengthened of this road to form the community’s main road to Napier Airport.
“A key focus for our project team was to protect and enhance the wetland area and the biodiversity that utilises it” says Project Manager Mike Job. “There are over 70 species of bird, including threatened species such as the Australasian bittern, New Zealand dabchick, banded dotterel and black-billed gull. It is also an important habitat for eels, fish and some shellfish.”
The focus of the earthworks was in five critical areas which needed to be completed simultaneously to ensure the construction programme was met.
- The earthworks required to begin the construction of scrape lakes to source type A1 materials, which were stockpiled and used on the new roadways for preload equated to 8,900m3. Specialised earthwork plant including excavators, dozer moxy and tracked trailers were used to gain access to the scape lakes locations and spread loads across the haulage routes and minimise damage through overloading. Haul roads were designed to avoid disturbing the kiwi habitat and to minimise disruption to wildlife within the wetland area.
- Significant relocation of sea rush and other native vegetation away from the construction area was completed early to avoid the August nesting period. We recognised that this project was harbouring fragile ecosystems and important biodiversity. To eliminate negative environmental impacts we outsourced environmental specialists for the duration of the project.
- Safety was carried out in accordance with Higgins Safety Policy and Site Safety Plan with no significant incidents recorded during contract.
- Pavement and surfacing - 27253m2 pavement and surfacing was undertaken by our Higgins Hawke's Bay team. This project required multiple pavement designs within the one construction area. This concept was challenging and required a high level of management to ensure the correct pavement treatment was selected. The parameters of these selections was based on the heights of existing pavement relative to new proposed finish levels. To achieve this Higgins undertook detailed topographical survey of the areas followed by detail analyses to ensure that the correct pavement treatment was selected. The pavement included geofabrics, geogrids, cement stabilisation of basecourse materials and structural asphalt. Higgins were able to offer solutions to the proposed design and implement a design build of the main asphalt area which accommodated local materials and allowed for a more progressive programme of work. This work was completed whilst maintaining two lanes of traffic flow through this difficult intersection.
- The barrier systems for this project included 1526m of TL4 Guardrail and wire rope barriers.