An environmental monitoring regime will be put in place at Hawea Flat this month so the Otago Regional Council, farmers and the community can better understand how the introduction of dairying will affect groundwater.
Lake Hawea Community Association chairwoman Rachel Brown, said this week, one of the biggest concerns facing residents was whether a dairy farm conversion on Camp Hill Station (2322ha) would affect the bore water supply.
"We want to protect our water, so we want to be assured that the effluent won't be getting into it," she said.
New Zealand-born but now living in Australia, Jim and Jenny Cooper, have bought Camp Hill Station which they plan to convert to a dairy farm, and they have applied to build two dairy sheds, a 54-bale rotary and a 40-aside herringbone, along with ancillary sheds and irrigation systems.
Hawea Flat resident Jeremy Bison also said on Wednesday he was keen for groundwater monitoring to begin now, so it could be used as baseline data and compared with other samples to see whether effluent run-off was changing water quality.
Otago Regional Council environmental information and science director John Threlfall confirmed yesterday a new style of lysimeter (a device developed by Landcare Research that collects soil leachate data) would be installed on a Hawea Flat farm within the next month. The council will also begin a separate ground water investigation of the Lake Hawea aquifer.
The lysimeter is the same as one recently installed at an Omakau dairy farm to study the possible loss of nutrients down into the groundwater.
The regional council recently received a report on samples taken from the Manuherikia catchment where most results showed good water quality and ecological conditions, but some "hotspots" were identified, thought to involve flood irrigation, which washed pollutants off the soil surface into surface water.
Dr Threlfall said the Hawea Flat lysimeter would be placed on a farm near Camp Hill Station that provides dairy support and wherethe farmer was spray irrigating with water, not effluent.
"At Hawea Flat, the ground water table is very deep but if people are taking their drinking water from the ground water I can understand they are concerned," Dr Threlfall said.
The Hawea Flat investigations had been planned for some time and the Camphill Station conversion was a "coincidence". The council needs the data to amend its water plan, which is under review, and the reports would be shared with farmers and the public.
Otago Regional Council resource management director Selva Selvarajah said once the Camphill Dairy farm began operating, his team would regularly monitor it for compliance with the water plan.
He understood residents were concerned about the first dairy farm in their neighbourhood but said if managed well, there should not be any problems.
"Hawea Flat over the last few years has been very intensively farmed for dairy (grazing) and large intensive cropping. It already has some sort of intensity so I don't think this will be any different," Dr Selvarajah said.
The water plan permits farmers to apply effluent like fertiliser, subject to conditions at a rate of 150kg a ha of nitrogen a year. The farm would be monitored like any other Otago dairy farm, with staff visiting to inspect effluent systems, storage ponds and soil conditions and initiating enforcement proceedings if breaches occurred, he said.
"We won't be treating it any differently to any farm in the region."
