The Queenstown-based department today starts its biggest visitor infrastructure development project this year, when contractors begin sealing 365m of access road from the Glenorchy-Queenstown Rd down the hill to the reserve.
The road will be closed between 7.30am and 6pm, Monday to Friday, from today to mid-November.
Doc recommended Moke Lake, 4.5km from the resort on the Glenorchy-Queenstown Rd, as an alternative camp site.
The cement stabilisation and sealing, designed to make the road suitable for all vehicles, is the first of three prongs in Doc's revamp of popular Twelve Mile.
The estimated 15ha to 18ha reserve is used by more than 40,000 campers, walkers, cyclists and tourism concessionaires with their clients every year.
Tenders close on August 20 for the construction of new toilets and landscaping, to be done by the end of November.
The fully contained unisex toilets would have standard and disabled cubicles.
Disposal would not occur on site.
About 8000 native plants typical of the delta environment were to be planted in the spring.
Improving Twelve Mile's boat-launching capabilities by creating a reversing point for vehicles and trailers aimed to take the pressure off demand at Wilson Bay.
Twelve Mile was "a gem waiting to be cut," Doc capital works project manager Richard Struthers told the Queenstown Times.
The upgrade had been on Doc's agenda for at least three years, but other projects had taken priority, or funding was not available.
The improvements "will have a significant impact on how people can take advantage of the area," Mr Struthers said.
"Twelve Mile is probably the prime lakeside recreation environment Doc [Wakatipu] administers.
You've got camping, swimming, fishing, gold-panning, boat launching and linkages to other trail networks."
Mr Struthers said Twelve Mile was the "hub at the centre of the wheel, with a few spokes to be connected".
"Eventually our objective is to link our 12 Mile walkway with Lake Dispute tracks and then that connects to Moke Lake and it becomes quite a good launching or destination point.
"And also connect the walking track to Wilson Bay. You could potentially walk from Twelve Mile to Arthur's Point, via the Moonlight Track."
