Tauriko Enabling Works

Project update

3 July 2024

Tēnā koe and welcome to the construction update for the SH29 Tauriko Enabling Works project. This update provides an overview of what’s happened and what’s coming up for the project.

In this edition, you can read about:

• where we are at and what's next
• temporary and permanent environmental controls
• building the roundabout offline for minimal disruption
• temporary traffic management – go with the flow

Construction of the roundabout and stormwater wetland area is underway. The location of the future centre of the roundabout is the large square pad in the top right of the aerial.

Construction snapshot: Where we are at

The Tauriko Enabling Works team has been busy for the past 2 months setting up access to the site and establishing the lay-down areas for storing materials, machinery, and vehicles.

Construction of erosion and sediment controls is underway. These controls are in place to minimise the environmental impact of the works on the nearby area, including the Wairoa Awa/ River, wetlands and vegetative habitats.

The Wairoa Awa is not only the largest freshwater tributary into Te Awanui/Tauranga Harbour but also a site of historical and cultural importance to hapū and the local community which is a significant factor in how the team carries out construction activities.

All works are being carried out under the careful watch of kaitiaki/guardians from local hapū to ensure any areas of cultural significance are identified and handled accordingly.

As well as the establishment of the site, the team has finished clearing a significant quantity of kiwifruit vines, shelterbelts, and other vegetation alongside SH29 and Redwood Lane.

Approximately 12,000m2 of topsoil has been removed and about 4,500 tonnes of structural fill brought in to help even out what was a heavily sloping paddock. This new, even surface has enabled work to begin on the areas that will become the foundations for the new roundabout and road layout.

Work continues with earth moving and compacting the base layers of what will become the new lanes of SH29, slightly west of the current SH29 lanes.

The SH29 Tauriko Enabling Works project team at the new site compound for their weekly health and safety meeting.

Graded metal being layered to construct the sub-base of the new tie-ins to SH29 traffic lanes showing the geotextile layer used to stop fine material moving up

What's next

With all temporary environmental controls in place the team will continue construction of the permanent stormwater settlement pond. They will also continue carting and compacting fill material for the construction of the new roundabout and road layout at Redwood Lane.

Winter earthworks are progressing on the northern end of the project site, with construction of the new traffic lanes that will become the tie-ins for the roundabout at Redwood Lane/SH29. This work includes removing the topsoil, organic material, and any soft ground before placing a special white fabric (geotextile) and building up the sub-base layers consisting of graded metal. This fabric stops the fine silts moving up through the sub-base layers when compaction and rolling take place, and provides an optimal foundation for construction of the road.

In the coming months, work will get underway on the stormwater upgrades in the Redwood Lane area and the undergrounding of overhead power lines at Redwood Lane to allow for construction of the new roundabout.

The stormwater upgrades will include installation of new stormwater catch pits/ chambers near SH29, between Gargan Road and Belk Road, with about 1,800m of new stormwater pipes being laid. The first phase of the stormwater upgrades is expected to take 3 months, before the team moves south towards Belk Road on the opposite (east) side of SH29.

The new Redwood Lane roundabout (artist impression)

Building a roundabout with minimal disruption to traffic

Prior to construction, we looked at the traffic volumes that use SH29 and we came up with a roundabout location and design that cause minimal disruption and keep the traffic flowing while we’re undertaking the works. In order to achieve those outcomes, an “offline” location was chosen which allows us to build the roundabout with only limited traffic management in place. We removed the slip lanes into Belk Road and Redwood Lane and changed the SH29 lane alignment allowing us to put steel barriers and guardrails in place to separate traffic from construction works – keeping everyone safe and moving. This new but temporary road layout, with some alterations to allow to build the tie-ins into the new roundabout, will remain in place for the duration of the works.

The location of the new roundabout has primarily been chosen to provide access from the southwest into the new Tauriko West community, planned by Tauranga City Council, and a new access to the Tauriko Business Estate through an extension of Kaweroa Drive. It also means, once the roundabout is complete, the existing SH29/Belk Road intersection will be closed, and traffic redirected through Tauriko Business Estate to the new SH29/Redwood Lane roundabout.

Overall, the roundabout will improve safety at both intersections of State Highway 29 with Redwood Lane and Belk Road.

New temporary traffic management keeps everyone safe and traffic flowing

The SH29 Tauriko Enabling Works project team recently carried out night works to install guardrails and safety barriers along SH29, which will remain in place for the duration of the project. These night works were aligned to take place at the same time as maintenance contractors were working on resealing sections of road on the Kaimai Range. This meant lower traffic volumes making it safer for workers and road users and reducing overall impact for road users.

The semi-permanent barriers and guardrails separate traffic from construction works – keeping everyone safe and moving. They provide increased protection to road users and our teams by clearly outlining the construction area, and require less maintenance, which means less disruption to traffic flow over the course of the construction period.

The speed limit on this section of SH29 has been temporarily reduced to 70km/h, and the left turn slip lanes into Belk Road and Redwood Lane removed. Removing the slip lanes on SH29 is required for stormwater drainage works, a culvert extension, and work around an existing gas main.

Road users are urged to stick to the signposted speed limit when travelling through the project site, for everyone’s safety.

Short-term sediment controls are in place: initial treatment pond and main pond.

What are environmental controls?

Every time earthworks take place, there is a risk of sediment being released into the environment, either through dust when it is dry, or through water and sediment-laden run-off when it rains.

As part of the many environmental responsibilities involved in construction, the team has been busy in the past few weeks establishing controls to prevent erosion and sediment spreading outside of the works site or reaching the Wairoa River while the works are underway.

Short-term sediment controls

For the project, sediment retention ponds and decanting earth bunds have been put in place. They have been designed and built for use throughout construction and will be removed at the end of the project.

There are currently three treatment ponds being established, with another 2 to be built later in the year as the project progresses.
How do these sediment controls work? Water from the site is diverted into channels that lead into an initial treatment pond before the run-off flows into the main pond and is discharged cleanly back into the environment. The water is discharged thought a floating pipe which releases only the surface layer of water (which is the cleanest) out of the pond, leaving the settled sediment in the pond.

The process acts like a filter and ensures water leaving the ponds meets consented discharge requirements; it slows down the water dispersal, preventing sediment from leaving the works area by allowing the time required for lighter sediment in the water to sink to the bottom of the ponds.

Construction of the permanent stormwater wetland is underway.

Long-term sediment controls

The new culvert extension and stormwater wetland which will be constructed near Belk Road will become a long-term solution to help channel and filter any water run-off from SH29.

The wetland will act as a natural filter for stones or sediment that spill over in any run-off and serves ecological purposes, as a habitat for wildlife including birds and fish.

This also creates more controlled release of water, although most of the time, this water is from rain and will not contain sediment because it is only in contact with the road, compared to the site works water run-off which comes from exposed soil. Wetlands also remove suspended solids, hydrocarbons and metals coming from the road run-off.

The constructed wetlands as well as the landscape planting within the natural wetlands as part of this project will contribute to positive sustainable outcomes.

More information

For more information on the Tauriko Enabling Works project:

Email us at bopprojects@nzta.govt.nz

Phone 0800 262 729 (Downer 24/7 freephone)

Visit our website www.nzta.govt.nz/tauriko-enabling-works