Rock ready to roll into new projects

Rock excavated from the hills above Sumner Rd will be put to solid use in other Council projects.

Sumner Rd, which links Sumner and Lyttelton as part of the Sumner Lyttelton Corridor, has been closed to the public since tonnes of rocks came tumbling down on to it from the surrounding cliffs during the 22 February, 2011 earthquake.

Rock excavated from the hills above Sumner Rd will be put to good use in other Council projects.

About 100,000 cubic metres of rock has been excavated from the slopes as part of rockfall protection work during the first stage of a massive multi-million dollar project to rebuild and re-open the road.

In the order of 10,000 to 20,000 cubic metres of the larger sized, more durable pieces of rock will be removed and stored at a yard in Bromley for use in key Council projects such as the Coastal Pathway, flood protection work, and heritage restoration projects, including the stone facings on Lyttelton retaining walls.

Starting this week the rocks will be loaded from the Gollans Bay Quarry below Evans Pass on to trucks to be taken through Lyttelton to a storage site in Bromley. 

Six to eight trucks will make hourly trips each night for up to 14 weeks.

The trips will be made at night to allow retaining wall construction work to continue during the day. The trucks will not use engine braking or reversing alarms and will operate at low speeds to minimise noise.

Using the rocks for other construction projects will bring significant financial benefits to the Council.

“This is about sustainability,” says Council Transport Planning and Delivery Manager Lynnette Ellis.  "Instead of having to buy new rock and transport it from sources as far away as Oxford or Akaroa, this local rock that has already been excavated is being reused for local projects. It makes good sense and it's extremely cost effective."

Some of the durable basalt rock will be used for erosion protection work along the Peacock’s Gallop section of the Coastal Pathway, which will begin around the middle of this year.

The current stage of the Sumner Rd project involves repairing and reinforcing nine retaining walls below Sumner Road and rebuilding the road itself.  Christchurch City Council and the NZ Transport Agency are jointly funding the work.