A Bailey bridge was put in place at the Creek Rd site this week.
An eight-metre-long bridge in rural Whanganui will cost around $845,000 to replace - $545,000 more than budgeted.
Creek Road Bridge at Mangamahu has a 4.5-tonne weight restriction and a maximum speed limit of 5km/h.
Whanganui District Council transport manager Damien Wood told a council operations and performance committee meeting therewas currently a “papa drive” culvert with bridge slabs over the top at the site.
The existing bridge deck was more than 80 years old and the culvert was now collapsing.
A Bailey bridge was constructed and placed there this week.
“It is not reinforced or lined and relies on the strength of the papa to support itself and the ground above.”
According to his report, the bridge provided the only access to five residential properties along with several forestry sites and sheep and beef farms.
It recommended the reallocation of funds from two other transport projects - the Mill Rd shared pathway and the design of the Whanganui City Bridge clip-on - to pay for the replacement.
Both were non-critical.
Wood said the existing bridge and culvert were regularly monitored and there was an application for funding with Waka Kotahi NZ Transport Agency.
However, the urgent nature of the work meant it had to get under way before that decision was made.
“Maintaining the Bailey bridge, which is the current status quo, there is an ongoing cost for that,” Wood said.
“We do have both the [Whanganui] Alliance and Emmetts Civil Construction ready to commence work on the permanent bridge solution straight away in the new year.”
The Whanganui Alliance is a partnership between the council and Downer Whanganui.
According to the report, the Bailey bridge cost $65,000 to install.
It said stock transport movement off the affected farms was pressing, with more than 2500 spring lambs needing to be moved before mid-December.
Bridge replacement and renewal programme needed
Council chief executive David Langford said there was a large “bridge-building programme” in the district around 100 years ago.
“Most of our bridges were built within a couple of decades of each other,” he said.
“You then get a nice, long holiday - you’ve built your bridges and you do a little bit of maintenance and paint them now and then with no major spends needed.
“They are now all coming up to their birthday. Because they were all built at the same time, they are all expiring at the same time.”
Langford said an intensive replacement and renewals programme would need to be in place in the years to come.
Earlier this year, funding of $1m was reallocated from the City Bridge clip-on project to fast-track the Aramoho pedestrian bridge after an engineer’s report revealed it needed replacing urgently.
That project is set to be completed by July next year.
Speaking to the Chronicle, Wood said the council had 72 bridges.
The Dublin St, Wakefield St and Erni’s bridges would need replacing in the next five to 10 years.
“We are currently going through an assessment programme to identify bridges for replacement so this list may grow once detailed bridge assessments are completed.”
The operations and performance committee voted unanimously to reallocate the funds for the Creek Rd project.
Mike Tweed is an assistant news director and multimedia journalist at the Whanganui Chronicle. Since starting in March 2020, he has dabbled in everything from sport to music. At present his focus is local government, primarily the Whanganui District Council.