Hawea Flat residents want the Hawea aquifer to be declared a drinking water protection zone, but Otago Regional Council director of environmental information and science John Threlfall says tighter water quality rules in a proposed water plan change "may well do the same thing" within the same timeframe.
Residents say a groundwater protection zone created under the existing water plan would offer significantly greater protection than if the land was left open to unrestricted dairy industry development.
Groundwater protection zones exist in other Otago catchments, such as the lower Waitaki Plain, Kakanui, Roxburgh and the lower Taieri.
"All our residents, our primary school and our kindergarten get their drinking water from the aquifer and so if this area doesn't qualify as a drinking water protection zone then I don't know what would," Preserve Our Water (Pow) spokesman Mark Thomas, of Hawea Flat, said this week.
"We have a relatively shallow aquifer and relatively free-draining soil structure, so our water is particularly vulnerable to any effluent disposal and nitrate leaching upstream of our bores."
Preserve Our Water has been lobbying the regional council about water quality protections since the recent announcement of a large dairy farm conversion under way on Camp Hill Rd, downstream of the bores.
The group is concerned about the possibility of dairy conversion upstream of Hawea Flat and members raised their issues at a public meeting hosted by the council in Cromwell last week.
Mr Thomas said Dr Threlfall had since told Pow in an email "there could be a reason to have some form of groundwater protection zone upstream of the Hawea Flat township".
When approached for clarification this week, Dr Threlfall said some of the existing zones were set up to protect drinking water but the reasons for others set up in the late 1990s had got "lost in the depth of time".
He did not think a protection zone could be obtained any faster than the plan change.
The council could not say "no" to dairy farming but could control the levels of nitrate spread on the land, he said.
`We are aiming for the same goalposts in two different, separate ways. Either could do the job. That is not to say we wouldn't do a groundwater protection zone. But at the moment I don't think that would be our first choice," he said.
The zones in other places were established for a variety of reasons and had resulted in controls on things such as nitrogen application, effluent and septic tank storage systems, and discharges of leachates, contaminants and industrial wastes.
Lake Hawea Community Association president Rachel Brown said a public meeting would be held with the Otago Regional Council at Hawea Flat Hall at 4pm on Sunday.
The meeting would be attended by regional council chairman Stephen Woodhead, Dr Threlfall and Wanaka Community Board chairman Lyal Cocks. Ms Brown said the purpose was to discuss water management issues in the Hawea district.
"Everyone interested in maintaining the quality of our water is encouraged to attend this meeting and ask pertinent questions and listen to what the Otago Regional Council has to say. It is their mandate to manage our water in the interests of all," she said.
