Whakatāne District Council anticipates it may need to enact its “Nessie” contingency this summer to draw the town water supply from further upstream.

El Nino weather patterns are expected to cause dry conditions over the next few months.

Extended dry conditions could allow saltwater to move further upstream in the Whakatāne River, and Whakatāne Water Treatment Plant, located near the southern end of Valley Road, will need to be monitored for saltwater reaching the normal water intake point.

When this happens, the council uses an intake attached to a barge further upstream to pump water from the river and pipe it back to the treatment plant. The equipment has been affectionately dubbed “Nessie” by council staff due to its serpent-like shape.

The amount of water that can be abstracted and conveyed to the treatment plant via Nessie is reduced compared with normal operations. As a result, water conservation measures and, if required, staged water restrictions may be introduced in the Whakatāne and Ōhope water supply areas.

In spite of this, three waters transition manager Nick Johannsen said there were no significant concerns about drinking water security, in a report to the projects and services committee recently.

No supply issues are anticipated for the district's other drinking water schemes, which are not affected by saltwater intrusion.

Johannsen added that the intent was for the council to eventually get out of drawing water from the river and use other water supplies like Johnson Road and Braemar for the total supply.

“That will de-risk that component for us. Of course, there will be some costs associated with the reticulation and also the resource consent component of that.”

Water conservation messaging would begin ahead of summer, encouraging residences and businesses to check for leaks, repair dripping taps and use water wisely.