The NZ Transport Agency advises State Highway 6 through the Haast Pass will close at 5pm this Thursday (12 December) and not re-open until 10am on Friday (13 December).
The closure is to remove the temporary steel plates and bridge the boxed culvert at the Diana Falls slip site, near the Gates of Haast, says the Transport Agency's Senior Network Manager Mark Pinner.
"This means State Highway 6 will close at the Haast township at 4pm on Thursday and at 4.30pm at Makarora, re-opening at 9am an Haast township and 9.30am at Makarora on Friday."
He says the work will enable the road through the slip site to be resealed early next week and minimise the need to continually clean the culvert.
"Resealing the road, which was damaged in September when 40,000 tonnes of boulders, rock and material fell onto the road, will also improve access for all road users travelling through the area."
Mr Pinner says the Transport Agency apologises for any inconvenience to road users as a result of the early closure and late opening.
The opening hours through the Haast Pass were extended last month to between 8am to 7pm. At the time, the Transport Agency did warn of the possible need to introduce some closures to enable work to be undertaken at the site.
"We have worked hard to minimise the delays for all road users. Much of the work to date in removing rocks and repairing the road has been managed with short 20-minute delays throughout the day."
He says the removal of the steel plates and bridging the culvert will take about six hours to complete.
"As always, our first priority is ensuring the safety of road users and the contractors working at the site."
If it is wet on Thursday/Friday, Mr Pinner says the work will carried out on Monday 16 and Tuesday 17 December; the road being closed from 5pm Monday night to 10am Tuesday morning.