Located about half an hour southeast of Invercargill, the Waituna Lagoon is home to several tracks, notably the 5km Wetland Loop Track which crosses manuka wetland and bog tarns.
The lagoon forms part of the much larger Awarua Wetland, which is deemed one of international importance under the Ramsar Convention.
But access to the tracks is frequently blocked — including at present — due to road closure from high lagoon levels.
Southland District Council strategic manager transport Hartley Hare said flooding had always been an issue at the site.
"It has been closed for substantial periods over recent times due to high water levels, with the exception of when work was carried out to upgrade the bridge in February and March," Mr Hare said.
The extent and severity of flooding were dependent on a number of factors including time of year, weather events and whether the lagoon had been opened to the sea, he said.
Meanwhile, the organisation revealed it spent $246,582 earlier this year to upgrade the road bridge leading to the tracks.
But if the work was not carried out, the only alternative was to close the bridge, Mr Hare said.
The Department of Conservation (Doc) is yet to update its website notifying of the lack of access to tracks at Waituna, with the district council saying it had not been specifically notified.
Both the department and neighbouring landowners were aware the road was closed from time to time, Mr Hare said.
Earlier this year, the lagoon made headlines after a toxic algae outbreak forced an emergency opening in January.
Environment Southland strategic regulatory adviser Bruce Halligan said no significant ecological concerns had been signalled from recent monitoring results.
Lagoon levels were "relatively elevated" over the last month in the 2.3m-2.4m range, he said.
A new consent application for emergency openings of the lagoon was lodged on July 5, with public notification likely to begin soon.
Spanning an area of 3500 hectares, the Waituna Lagoon and its immediate surrounding area form part of the Awarua Wetland, which clocks in at 20,000 hectares.
■LDR is local body journalism co-funded by RNZ and NZ On Air.
