The Otago Regional Council commissioned consultants Castalia Strategic Advisors to make an economic assessment of the effects on the community of not taking steps to improve the lake's water quality.
The council's director of stakeholder engagement, Sian Sutton, said nine people showed up to hear the consultants present their draft report in what was a ``robust and passionate'' session.
The draft report was part of ``doing due diligence'' on any spending necessary for remediating the lake.
The audience was made up of representatives from the Friends of Lake Hayes, the Lake Hayes Community Association, a residents' group and Amisfield Winery.
Other organisations invited but not represented included Otago Fish and Game, the Department of Conservation and the Queenstown Lakes District Council.
Friends of Lake Hayes secretary Richard Bowman said the group was pleased with the draft report, which showed there was an ``economic benefit that justified investment in the lake''.
Ms Sutton said the draft report and feedback from the meeting would be discussed by councillors at a workshop.
The wider community would be consulted, beginning in August or September, on the remediation options.
Community discontent over the state of the lake's water quality has grown steadily in the past decade. Since 2006, algal blooms have worsened, leading to a decline in water quality, fish kills and skin irritation for swimmers.
The issue has become heightened in the past 12 months as the council has closed the lake for swimming several times because of high E.coli levels.
The issue dominated submissions at the council's long-term plan hearing in the resort in May, some submitters accusing the council of neglecting its duty to protect the lake.
A report last year by University of Otago freshwater ecologist Marc Schallenberg, commissioned by the Friends of Lake Hayes, proposed a multi-pronged, long-term strategy for remediating the lake.
The options were to limit run-off into tributary Mill Stream through better land management, flushing the lake with irrigation water, dosing it with ``alum'' to bind phosphorous to the lake's bed, and manipulating its ``food web''.
