Further water restrictions for some in Central Otago

Image: CODC
Image: CODC
Water restrictions have been tightened in some Central Otago towns amid near-drought conditions in many areas.

The Central Otago District Council (CODC) this morning said Omakau, Ophir, Naseby and Ranfurly had been moved into the Red Drop water conservation status.

This highest conserve water status requires a total ban on sprinkler use but does allow for handheld hose for garden watering only.

CODC Three Waters Director Julie Muir said the low water level in Falls Dam was affecting the availability of water in the Manuherikia catchment, which prompted the move for Omakau and Ophir.

She said the same setting also applied to Naseby and Ranfurly, to reflect the very low water levels in their water supply source.

The Otago Regional Council had recently advised of near-drought conditions across much of the South Island and was cautioning Otago farmers, along with rural and urban communities to consider conserving water in the weeks ahead, she said

“We are reaching out to the community to do our part within the Manuherikia catchment. 

“As well as the sprinkler ban, we are asking the community to check how they can reduce their water use throughout our homes and business.”

Low flows can already be seen in the Manuherikia River. The Otago Regional Council is urging...
A low flow in the Manuherikia River. PHOTO: RUBY SHAW

Taste and odour issues at Omakau

The decrease in the level of the Manuherikia has seen an increase in complaints related to the taste and odour of the water supply in Omakau and Ophir - an issue these communities have been experiencing for periods over the past year.

An investigation found the cause to be a naturally occurring chemical called geosmin, which is produced during the breakdown of algae and other micro-organisms in the raw (untreated) source water.

“Geosmin has a distinct earthy or musty odour which most people can easily smell and causes most taste and odour outbreaks in drinking water.

Seasonal increases in naturally occurring algae or bacteria in water can cause geosmin levels to increase above the tasting threshold,” CODC Three Waters Customer and Compliance Team Leader Philippa Bain said.

“Although the taste and odour can be unpleasant, geosmin is not harmful to health.”

Given dropping river levels and hot conditions, testing for cyanobacteria was undertaken to ensure the safety of the water source. Geosmin can be produced during the breakdown of algae and can be linked to a cyanobacteria event. All lab samples have showed no levels of concern.

Unfortunately, due to the low river levels, taste and odour issues may continue until flows in the Manuherekia River increase again and temperatures drop.

Since this event, CODC has had contact with residents in the community who have noted that the severity of the taste and odour issue has fluctuated over the past two months.

“People within the community do have different levels of sensitivity to the taste and odour, some noticing it more than others,” Ms Bain said.

There had been concerns raised from the community about the safety of the water.

“We acknowledge the frustration and discomfort related to the taste and odour issue but want to assure the community that the water supply is being monitored closely. Any concerns that water is unsafe are taken very seriously and we will ensure the community are aware of any issues.”