A potentially long, hot summer is in store for Central, prompting calls to conserve water to prevent stocks from drying up.

Central Otago District Council (CODC) plans to launch a campaign in the coming weeks, calling on people to use water wisely.

A CODC water services spokesperson said being cautious when using water now can make a difference, and potentially prevent any conserve water notices.

Naseby is among the towns that have experienced conserve water notices in recent years, including in January 2021 after widespread flooding. 

Its water supply is sourced from an open irrigation race, which the council treats and distributes.

The CODC water services spokesperson said the district's other large water bodies such as the Clutha River or Lake Dunstan can create a perception that there is a boundless amount of water available.

"Therefore, it naturally takes time for the water conservation message to really register with people.”

The water services team agreed that getting the message out early could help, particularly as visitors would soon arrive in the district, adding extra pressure on water supplies.

Treating a raw water source to make it safe to drink takes time and a lot of resources.

“The rising costs of electricity and methods of treatment used to make each litre of our water, make it more and more expensive to produce. Reducing demand helps us to manage these costs.”

There are several reasons why demand for water threatens to outstrip supply in Central, particularly over summer. 

“One occurs during the height of summer when visitor numbers are high and the days are hot. The process of treating raw water to a safe/potable level takes time.”

The treatment technology available at each plant is different and comes with their own challenges.

“What they all have in common though is that the raw water doesn’t instantaneously become safe to drink. It takes time to pass through each level of treatment.

“This is why we have reservoirs to store treated water and distribute it while more is being produced.”

The team also points out that demand for water can outstrip supply in extreme rain events.

“Our surface water sources of ‘raw’ water can become muddy (turbid). The rise in levels of turbidity make the treatment process less effective and/or impossible. 

“However, if we can’t treat the water adequately, then we stop producing it and rely on what is stored in the reservoirs. It takes time for turbidity levels to return to normal after a decent rain event, so we need the public to conserve water until we can begin producing safely treated water again.”

Visit the CODC website for tips on how to use water wisely this summer.

Read more: Prepare for hot and dry Central summer.