Tauranga water supply may need more than a year to recover, tighter restrictions loom

Water restrictions appear to be working for some but "we're not out of the woods yet". Photo / Getty Images

It could take more than a year for Tauranga's water supply to recover after "extremely dry conditions" and the city council has not ruled out imposing tighter water restrictions.

Despite this, Tauranga City Council water services manager Peter Bahrs said people's efforts to better manage their water usage was "making a difference".

On November 22, the Water Watchers Plan came into effect allowing sprinklers to be used only to water gardens for an hour per evening. From December 1, stricter rules came in including a ban on sprinklers, irrigation systems, filling pools and spas (unless granted), high-pressure cleaners and handheld hoses with a trigger nozzle.

These restrictions are expected to soften from April 1 but rules will remain throughout the year in varying levels.

Last week, Bahrs said the plan was mostly working but levels in the Tautau and Waiorohi streams, where the city draws its water supply, were "still extremely low and water flow levels in the Tautau Stream in particular continue to decline".

Both streams were aquifer-fed, meaning groundwater levels need to recharge before stream flows could improve.

"After three dry summers in a row groundwater levels are so low we know it will take at least a year of more regular rainfall for these streams to recover."

Tautau Stream flows over the years. Image / Tauranga City Council

A Niwa seasonal climate outlook released last week for the Bay of Plenty predicted a 40 per cent chance of "normal" rainfall and a 35 per cent chance of "above normal" rainfall between February and April.

The report also referred to "extremely dry conditions" in the Western Bay of Plenty, Auckland, Northland and Waikato during January.

Metservice said yesterday that 57.1mm of rain fell in Tauranga between 10am Sunday and 3pm Monday.

Bahrs said while the city could not control the weather, people could manage water wisely "which is why we introduced the Water Watchers Plan last year".

The plan replaced traditional outdoor watering restrictions with a year-round framework to help maintain Tauranga's water supply.

Bahrs said he wanted to thank those people adhering to it because it was "making a difference".

"While we're very conscious of the low water flow levels in the streams that supply our city with water, we're also appreciative of the efforts our communities are making to follow the Water Watchers Plan, which is helping to reduce water demand."

Bahrs would not say how many people the council was aware of for reportedly breaching the restrictions.

"So far we've contacted all concerned reminding them of the plan and where necessary warning them of non-compliance but at this stage we haven't needed to take further action."

Bahrs said if people continued to follow the plan "we may not need to introduce tighter water restrictions".

"However if stream flows continue to decline, or if water use increases significantly, we'll notify the community and, if necessary, introduce tighter restrictions, including a total hose ban."

Western Bay of Plenty District Council utilities operations manager EJ Wentzel said water demand in January had been consistently higher than previous years "and we attribute this to the high daytime temperatures we've experienced".

Waiorohi stream flows over the years. Image / Tauranga City Council

However, since the council began alternate day sprinkler restrictions on January 18, the demand dropped significantly.

"The sprinkler restrictions combined with some rain helped to reduce demand between 15 and 30 per cent across the district."

Wentzell said the council was not concerned for now because of savings already being achieved.

"Our community are doing a great job saving water and we need them to keep it up. February is normally the period with the highest demand for water, so we are not out of the woods yet."

Wentzell said the council has, to date, only received one complaint about a person not adhering to the water restriction.

"Our approach is to educate the community rather than prosecute."