The NZ Transport Agency (NZTA) will close Milford Road from the eastern entrance of the Homer Tunnel for between 10 and 14 days from this Thursday (23 May), to carry out emergency safety work to remove an unstable rock feature high above the western entrance to Homer Tunnel.
Part of the rock feature broke free in November 2012 causing disruptions traffic on Milford Road.
“We have a limited window of opportunity before the on-set of winter to remove the remaining unstable rock feature using carefully targeted precision blasting but we have to act immediately,” says the NZTA Southland Area Manager Peter Robinson.
“Weather permitting, the emergency works can begin this Thursday to remove rock from the area known as Moir’s Mate Diamond Face.
“The NZTA continued to monitor the feature with road user safety being its prime consideration. An on-site inspection last week by our geotechnical experts showed that the remaining section of rock weighing about 2000 tonnes and about 20 metres high is now largely detached from the rock face and likely to fall when it comes under pressure from the winter freeze/thaw conditions.”
Mr Robinson says New Zealand firm Geovert, which has vast high altitude blasting experience both in New Zealand and overseas can be on site from Thursday to begin the work. This company has worked on several high-profile rock stabilisation projects, including the Nevis Bluff and Manawatu Gorge slip.
“There is only a narrow window of settled weather to do this work before winter conditions set in at the site and makes it impossible to complete the work. If we can’t complete the work before winter there is a risk it could have an impact on enabling us to keep the road open throughout winter.”
Mr Robinson says road user safety is our top priority. ”Successful completion of this emergency work will ensure greater stabilisation of the rock face and ensure safe access is maintained between now and the start of the busy summer tour season.
“Full road closure is required while drilling and blasting work is carried out. Depending on several factors, especially the weather, the first drilling and blasting closure could be between 10 and14 days.”
He says the NZTA acknowledges the closure will be disruptive and has met with local tour operators and businesses to explain the situation and the need to move quickly to bring this unstable rock down in a managed way. “While there is never an ideal time to do this sort of work, right now is likely to be the least disruptive with Milford visitor numbers at seasonal lows.”
The latest information about the status of the Milford Road is available at www.highwayinfo.govt.nz(external link) or by phoning 0800 444449.
View information about the Milford Road rockfall risk(external link).