Dannevirke: Unique view on skinny bridge work

Work is well underway on the New Zealand Transport Agency's $6.5 million project to replace the Whakaruatapu (skinny) bridge at Matamau on State Highway 2 north of Dannevirke. The work began last November and is on time to finish in November next year.

223 fish and 10 fresh water crays relocated after stream diversion

DANNEVIRKE'S Dave Donaldson has a unique view of the progress being made on the New Zealand Transport Agency's $6.8 million Whakaruatapu bridge replacement at Matamau.

Mr Donaldson, a pipeline mechanical technician with Vector, flies over the gas line alongside the project works each month as part of his job and has been able to photograph progress.

Work began last November on the NZTA's new bridge/culvert structure which will be about 4m wider than the existing bridge, known to locals as the skinny bridge.

The project will see the stream pass through a large culvert to form the new bridge, with the effect being motorists will hardly know they have just crossed a bridge. Widening the highway will also have enormous safety benefits, reducing the risk and severity of crashes

"We're making encouraging progress on the bridge and in October the stream was diverted into the newly completed arch-culvert," project manager John Jones told the Dannevirke News.

The majority of the arch-culvert was completed in early October with the inlet channel rock first completed in the dry with a bund left between the new channel and the old to keep them separated.

The stream was allowed to flow through the new channel and into the culvert. Following the permanent diversion of the stream the old stream channel was cleaned out to waste and a drainage layer placed to allow the existing groundwater flows to be maintained. "Towards the end of the month, we began earthworks operations from the cutting on the northern side of the bridge to the fill on the northern side of the arch-culvert," Mr Jones said.

Ecologists have been employed to relocate fish from the old Whakaruatapu Stream following the stream diversion. The 223 fish of five different species and 10 freshwater crayfish found have been happily relocated upstream from the site.

The new bridge/culvert will also be built to modern seismic standards, able to withstand a large earthquake and work is expected to take two years.