Friends of Lake Hayes is urging the Otago Regional Council to more speedily come up with options for restoring the scenic lake, which continues to be blighted by toxic algal blooms.
The regional council closed the lake for recreation for periods in February and March because of a risk to people and dogs posed by the green or yellow algae produced by cyanobacteria.
Group chairman Mike Hanff said another indicator of the lake’s poor health was a reduction in trout numbers, the few fish remaining struggling to survive, particularly in summer.
"The recent observation of numerous dead trout in the lake highlights the stresses that trout in the lake must now endure."
Mr Hanff said the council had been more responsive to the group’s ideas in the past two years, and the installation of a water monitoring buoy last July was a welcome development.
In a submission on the regional council’s proposed annual plan for 2020-21, the group said it wanted the 1995 Lake Hayes management strategy reinstated and brought up to date, an integrated lake and catchment management plan developed, and support for a community-led wetland restoration and riparian planting project in the lake’s catchment.
If the original strategy had continued to be implemented, the lake would "already be well down the track to recovery by now", the submission said.
"The sad thing is, that while so much discussion and debate has been going on about the state of the lake, no positive actions have been undertaken in the lake or catchment since then."