Earthworks are being carried out along Matapihi Road, exposing a number of utility services that need to be relocated. All services need to be moved out of the way before beginning pavement construction.

What happened in April

Last month, work continued around the Maunganui-Girven intersection and along State Highways 2 and 29A, near Baypark.

This work included:

• Progression of earthworks for the new northbound on and off ramps at the Maunganui-Girven intersection and Matapihi Road.
• Ground improvements were completed at the new SH29A roundabout.
• Service relocation started on Matapihi Road, and relocation of power and gas along SH29A and SH2 continued.
• Location and protection of underground services.

The works around Harris Street and Bayfair Shopping Centre are part of the Bayfair expansion and not related to this project.

The gas relocation involves welding a series of new pipes together to form ‘strings’. A drill then creates holes underground, large enough to pull each ‘string’ back through so they can be connected to the gas network. Pictured is the ‘string’ on SH29A being pulled back through, towards Truman Lane.

What to expect during May

During May the focus will continue around the Maunganui-Girven intersection and State Highways 2 and 29A as we prepare for road surface construction of the new northbound lanes.

You can expect:

• Earthworks will continue along Matapihi Road, and on the new northbound on and off ramps at the Maunganui-Girven intersection in preparation for pavement works.
• Chip sealing will take place along SH29A, in preparation for moving traffic towards Baypark to create a work zone along the eastbound verge.
• Relocation of services and the installation of new ducting will start on Girven Road and will continue along Matapihi Road and SH2 northbound, between the Te Maunga intersection and Concord Avenue.
• Service relocation works will continue with the installation of a new gas line in the south and new power cables near SH29A.

A 50km/h temporary speed restriction is in place throughout the site for the duration of the project for the safety of drivers and their passengers, and also for the people working on the project. Please take care driving through the site.

A detention device was installed near SH29A to manage stormwater during the heavy rainfall event at the end of April.

Managing Stormwater

Most rain or other sources of water on site usually filter down through the sandy ground until they hit the water table about 0.5-2 metres below ground.

Issues can arise when there is prolonged heavy rain. This can saturate the sand, pushing the water table up as high as the surface, as happened at the end of April when 90mm of rain fell in 24 hours. Combined with this, given the site's proximity to the sea, the water table moves up and down with the ebb and flow of the tide.

When there is a high tide and a flood event, water cannot drain into the ground, leaving it to build up on the surface and flow to the lowest point above ground. When this happens we rely on our engineered controls to prevent dirty water discharging off our site, by using devices like the stormwater detention device pictured.

Water becomes ‘dirty’ when it flows over exposed surfaces and picks up sediment particles like silt and clay. They can cause damage to aquatic ecosystems. Detention devices allow the sediment to settle, and the water is then tested to ensure it is clean before being discharged from our site.

Contact us

For more information on the Baypark to Bayfair Link upgrade project, contact us baylink@nzta.govt.nz

Visit our website www.nzta.govt.nz/baylink