Work will begin in the spring to repair the East pedestrian bridge at the Crook O'Lune which links Caton with the River Lune Millennium Park.
The listed bridge near Lancaster will be closed until late summer while it is fully restored.
It was originally closed for safety reasons in March 2011 after an inspection unearthed problems with the structure, particularly with the timber beams underneath. The bridge has since been reopened with a temporary deck supported by scaffolding above the old timber deck.
A decision was taken today (Monday 14th January) by Lancashire County Council leader Geoff Driver to invest in a full restoration which will see the timber decking replaced, ironwork repainted, and the masonry! re-pointed.
He said: "The Crook O'Lune is a beautiful and historic part of Lancashire and the East Bridge is an important part of the recreational site which attracts around 250,000 visitors a year.
"It's therefore vital that we continue to protect this listed structure and carry out the repairs needed to make sure it lasts for future generations.
"Even in these difficult financial times it is vital to preserve our heritage and I am delighted that we are able to invest what we estimate may cost up to £1.5m to fully restore this bridge."
The bridge near the Crook O'Lune picnic site and Millennium Park carries the River Lune Cycleway which is a popular route for cyclists, walkers and horse riders. The nearby toilets and cafe facilities will be open as normal while work takes place.
A diversion will redirect people over the Caton Lune Bridge on Low Road, where a temporary walkway will allow them to cross - alongside the traffic.
Footpaths underneath the bridge were diverted at the end of last year as a safety precaution after a further inspection of the old wooden beams showed they had continued to deteriorate.
As a listed structure, planning permission is needed to carry out the work and an application has been submitted to Lancaster City Council. Lancashire County Council is also consulting with the Environment Agency and Natural England to ensure any impact upon the environment is minimised.
The county council will announce exactly when the closure will begin once the work has been scheduled.