Work to strengthen the Hinahina bridge over the tidal Catlins Lake will go ahead after the $1.13million budget for the project was approved by the NZ Transport Agency.

The Clutha District Council says the bridge has deteriorated over several years and was under severe weight restrictions for safety reasons.

The NZTA will contribute 59% of cost to strengthen the bridge while the council would pay the remaining 41%.

The strengthening will allow vehicles as heavy as 44 tonnes to cross the bridge.

Bridge closures will be expected once work commences but it was necessary to bring the bridge up to standard.

Tenders for the project close on March 27.