The Dunedin City Council will consider largely filling in Dunedin's scenic Ross Creek Reservoir, following the discovery of cracks in the dam's embankment.
Only a smaller "decorative pond" would be left.
The option was one of three outlined to councillors at yesterday's infrastructure services committee meeting by council water production manager Gerard McCombie.
The other two involved strengthening the dam's embankment, or demolishing it, to return the area to its original condition with "considerable" landscaping and native-tree planting, he said.
The ideas came after council staff last week revealed large cracks had been discovered across the surface of the 143-year-old earth dam's embankment on June 3, following a week of torrential rain in late May.
The discovery was not revealed for three months, as council staff and consultants examined the dam to ensure it remained safe, lowered its water level by 1.5m and increased monitoring of its stability.
Opus International Consultants staff also recommended its upgrade be accelerated, with work carried out within five years rather than within 20 years, as originally scheduled, Mr McCombie said yesterday.
The dam - also a popular Dunedin walking spot - was completed in 1867 and was designed to hold 122,000 cu m of water, now used as a raw-water backup to the city's main supplies.
Opus staff would now examine the three options for its future in more detail, and present a report - including possible costs - within two months, Mr McCombie said.
Councillors would then be asked to make a decision on the dam's future.
Council water and waste services manager John Mackie did not return Otago Daily Times calls last week, but yesterday defended the decision not to inform those downstream from the dam.
The owners of the Leith Valley Touring Park told the ODT on Friday they believed they should have been told of the damage, but Mr Mackie said it was not necessary to "alarm the community" once the dam was found to be safe.
The report was now also in the public domain, and there was "no agenda for secrecy", Mr Mackie said.
