Doc announced the temporary and intermittent closure of the Sugar Loaf Bridge from September 1 to mid-October for remedial work.
The entire Great Walk will remain open and a route across the stream will be marked.
People could decide for themselves on the day whether the stream was safe to cross, Doc said.
John Henderson Construction Ltd, of Glenorchy, is the department's contractor for the bridge.
The job was part of works scheduled for the popular Routeburn over the coming year.
The works included completely replacing the Routeburn Flats swing bridge, to increase the maximum five-person to a maximum 10-person load; plus maintenance work on the Twin Stream Bridge and major works upgrading tracks between Flats and Falls huts.
Doc Wakatipu visitor assets ranger Danny Higgins said all the bridges being replaced or upgraded were built by the New Zealand Army after floods in the 1990s which significantly damaged the Routeburn.
"The bridges are now due for an upgrade and will be improved to increase carrying capacity," Mr Higgins said.
The 32km, two- to four-day Routeburn Track is the nearest Great Walk to Queenstown and attracted 11,052 trampers last season.
Doc's commercial business unit, in Wellington, recorded 21,730 bed nights for adults and children in the 2011 to 2012 season, with a peak of 4925 in January.
