Trail trust chairman Rod Peirce said successful tenderer Homer Contracting was due to start on the Lawrence to Cockleshell Rd section, which would be relatively easy as it was on an old railway line.
"It's more like a tidy-up and spread some top gravel ...There are a couple of bridges to go in but they are under construction."
Earlier this year, construction began on other sections: 9km from the Roxburgh dam to Roxburgh, and a 23km section from Roxburgh to the mouth of the Beaumont Gorge at Minzion Burn. While Mr Peirce estimated between only 2km and 4km had been completed, he said the rest was not far away, some sections needing only a final top-dressing of gravel.
"It takes a while to do each section ... [We] need a heavy rain to be part of the process." Heavy rain would show weaknesses in the land, and any slips or potential slips could be fixed.
Two bridges are also to be installed in these sections: one at Butchers Creek in Roxburgh East and another over the Teviot River.
Mr Peirce described the trail section which passed Pinders Pond as a "trial" section where the contractor was fine-tuning construction methods. That section would be open to the public on Sunday from 2pm to 4pm to give people an idea of what the final product would be.
Although people are asked to leave their bikes at home because of the number of people expected, people would be able to walk 1km either way from the Pinders Pond campground and car park area.
Mr Peirce said trust members would be on hand to guide visitors and talk about the trail.
He said "a lot of people had been going to Pinders Pond to inspect the trail at weekends and the community was "beginning to take ownership" of the trail, and the trust was hearing "so many good comments" which had helped spark the plan for the open day.
However, Mr Peirce warned the trail was still a construction site and, as such, was effectively closed to the public, except for the open day. He warned contractors were still working on the trail during the week.
In its entirety, the trail will cross 11 private sections for which land-use easements have been obtained, Central Otago and Clutha District Council road verge, New Zealand Transport Agency road verge, Contact Energy, Land Information New Zealand and marginal strip land.
Mr Peirce said the completed trail between Roxburgh dam and Lawrence was scheduled to be opened early next year. It is part of the Nga Haerenga, New Zealand Cycle Trail network, will cost $5.5 million to build, $3.8 million of which will come from government.
It follows the true left of the Clutha River to Beaumont, then winds through rural valleys to Lawrence.
It is intended the trail will link up with the 34km Roxburgh Gorge cycle trail between the Roxburgh dam and Alexandra.
Construction at the Alexandra end of the gorge trail has slowed since the trail trust began renegotiations with Bruce and Leigh Johnston, landowners on the section, after the couple voiced safety concerns which effectively stalled construction around their land.
Trail trust chairman Stephen Jeffery said the delay brought a silver lining: it meant the contractor building the trail could begin work near the Roxburgh dam, speeding up progress at that end.
However, the Alexandra delay had pushed the trail timeframe back "a bit" and instead of the 10km Roxburgh Gorge section being completed by June as scheduled, it would now be "well into spring" before it was finished.
Work began on that section in November.
Mr Jeffery estimated a little more than 4km of the trail had been completed so far. The middle section was still a "work in progress".
