Mangaweka Bridge expensive to keep - even if only for walkers and cyclists

The Mangaweka Bridge is soon to be replaced. Should this old and historic bridge be kept as well? Photo / Bevan Conley

A proposed new bridge across the Rangitīkei River has called the fate of the current bridge there into question.

The Mangaweka Bridge is cantilevered and was built in 1904. Heritage enthusiasts say it's the only one of its kind left in New Zealand and should be kept, as a "tourist icon".

But keeping it working - even if only for pedestrians and cyclists - would cost $700,000 up front and a further $3.8 million over 50 years, a Rangitīkei District Council report says.

The cost would be shared between the Rangitīkei and Manawatū councils, with the New Zealand Transport Agency (NZTA) not contributing.

Or, if the bridge was gifted to a heritage body, that body would be liable for costs.

The public and the two councils are being consulted about whether they want to keep the bridge. If it's demolished NZTA will pay a percentage of that cost, as part of the new bridge contract.

The bridge crosses the Rangitīkei River into Manawatū about 1km east of Mangaweka township. It was closed for 15 days in 2016, for repair to its timber deck.

During that time traffic had to make a long detour over a more difficult road, Rangitīkei Mayor Andy Watson said.

While the repair was happening, more problems with the bridge were found.

When it reopened the weight of vehicles using it was restricted to six tonnes. This excluded stock trucks and trucks carrying asparagus from the Turney farm in the Kawhatau Valley.

The speed limit became 10kph, and no stopping was allowed.

The two councils began the process of applying to NZTA for funds to build a new bridge in September. They are confident they will get the money, Watson said.

The new bridge is being designed, and property 30m downstream must be bought. The total cost is estimated at $11 million.

Each council is responsible for half, with NZTA paying 63 per cent of the Rangitīkei portion, and a similar percentage for Manawatū.

The new bridge is to be 132m long and have steel plate girder construction and a 55 tonne weight limit.