Gore district councillors will discuss options for Mataura's water supply at the council's operations committee meeting on Tuesday, including connecting Mataura households to the Gore township water supply.
In a memo to be discussed on Tuesday, district assets general manager Paul Withers said issues at the Pleura dam, which was fed by the Pluera Stream and supplied the Mataura urban area with water, had raised questions of the supply's long-term viability.
A resource consent issued by Environment Southland (ES) to take water from Pluera dam was due to expire in February.
A new consent had been applied for which included cleaning the dam.
A consent to take water from Waikana Stream had also been applied for, Mr Withers said.
Pluera Stream was the subject of an ES investigation at the beginning of the year following its contamination when a system installed by GDC to remove silt from the dam failed.
ES decided to prosecute the council in relation to the incident, but the matter is yet to go to court.
However, Gore District Mayor Tracy Hicks said yesterday ES had encouraged the council to take a restorative justice approach to the matter.
The contamination served to heighten awareness about the issues with Mataura's water supply, Mr Hicks said.
"Water supply in both Gore and Mataura is a huge issue. [The council] needs to take time working through them [in order to] secure the future for both communities," he said.
In his memo, Mr Withers said the removal of silt at Pleura dam would cost more in the future.
"This is due to the proposed cleaning method requiring heavy machinery and the need to cart the silt to a suitable location for disposal."
Indications from ES were that the minimum flow at Pleura dam needed to be increased from two litres per second to 10 litres per second.
"This means that the Waikana take will require more frequent use. However, there will also be an increased minimum flow set for the Waikana Stream," he said.
When the minimum flows were reached, the council would have to use the emergency take from the Mataura River.
Councillors would consider options including:
> Locate a new source of water supply.
> This would require buying land and exploratory drilling.
> Apply for a surface take from the Mataura River.
This would require upgrading the water treatment plant. The Mataura River conservation order would most likely prohibit the granting of a consent.
> Connect the Gore and Mataura water supplies. With a new well showing promising test results at Jacobstown, the water quantity potentially available combined with other wells in Gore could meet the requirements for Gore and Mataura.
It was recommended funding be sought from the Ministry of Health to connect Mataura to the Gore water supply and that a working party investigate the options.
