The new Millwater Interchange was officially opened today (13 May 2015), providing direct access to the new growth areas of Millwater and Highgate Business Park from State Highway 1.
The new interchange will allow thousands of current and future residents of the Millwater residential subdivision direct access to their homes from SH1, removing traffic from nearby Silverdale and the Hibiscus Coast Highway, and will also help streamline journey time and access for more than 4,500 people expected to be employed in the new Highgate Business Park by 2025.
Development of the interchange was a requirement of the original consents issued to the developers by the former Rodney District Council when the new subdivision and business park area were proposed.
Millwater residential subdivision developer WFH Properties Ltd and Highgate collaborated on the project, working through design and consenting in partnership with the NZ Transport Agency and Auckland Transport. Construction was undertaken by Ross Reid Contractors, Woods and Fulton Hogan.
Full ownership of the interchange will be handed over to the NZ Transport Agency in 12 months time.
“This project is another successful example of stakeholders working together to plan ahead for an important new growth area for Auckland. The new connection to the motorway also helps to reduce local road pressure in the surrounding areas and took into account the environment and landscape,” NZ Transport Agency Auckland and Northland Highways Manager Brett Gliddon.
The Millwater Interchange went through numerous design options over a six year period until meeting all the requirements of NZTA and Auckland Transport, all for an acceptable cost.
The project required some challenging design and construction techniques, successfully managed by all those involved working closely together. These challenges included:
Designing the Interchange around existing infrastructure with limited disruption to the public and services.
Providing environmentally sound practices in the treatment of stormwater runoff to the sensitive receiving waters of the Orewa River / Estuary
Undercutting retaining and strengthening of the existing Wainui Road Bridge West Abutment, while enabling cars to continue to use the bridge.
Geotechnical remediation of the existing motorway slip.
Constrained construction deadlines due to the link between the completion of the Millwater interchange and the release of residential lots within Millwater Subdivision. This included working through some tough winter conditions in 2014.
The construction budget for Millwater Interchange was $16.9m. The actual costs are expected to be less than this.
“The opening of the new Millwater interchange, one of the largest privately funded pieces of motorway construction in New Zealand, represents a significant milestone in the development of the area, releasing more sought after sections and allowing business and work opportunities to grow along side the increasing population” says WFH General Manager Graeme Causer.
“The Ramps will enable the development of what we expect will become a thriving business estate, to the same extent that Millwater is now a well-established and thriving community” says Highgate’s Development Manager Alistair White (of Planning Focus Ltd).
The developers, officials, local residents and business guests gathered to witness the ribbon cuttung and the first car use the new on and off ramps and over bridge before it was opened to the public at midday.
The new interchange includes:
A Northbound off ramp on SH1, which links to Wainui Road and circles across the overbridge to Millwater and Highgate
An upgrade of Wainui Road including two new roundabouts
An upgrade and widening of the Millwater Parkway from Bankside Road to the overbridge
A Southbound on ramp to SH1 from Millwater Parkway.
More than 16000 vehicles are expected to use the new Millwater interchange every day by the year 2021 providing an efficient connection back and forth to central Auckland and Albany, and easing pressure on local roads.
Note: SH1 motorway traffic travelling from Northland southbound will still access Millwater, Highgate, Silverdale and Owera via the Grand Drive and Hibiscus Coast Highway offramps.