Vital upgrade underway at Waingake water treatment plant

Thursday 12 October, 2023

A vital upgrade is underway at the Waingake water treatment plant to enable us to cope better when drought conditions hit over summer.

During the upgrade, the city’s water supply will be impacted, which means we’ll need to manage the city’s water demand.

“To achieve this, restrictions on sprinklers may come into effect by the end of October,” says Council’s Community Lifelines Acting Director Dave Hadfield.

“The reason for the restrictions is we may not be able to maintain capacity to our city reservoir tanks for pressure management, emergencies and firefighting purposes during this time.

“There is sufficient water for everyone but we’re asking households connected to the treated supply to please be mindful of their water use.

“While all three of the dams that supply 70 per cent of Gisborne’s water supply are full going into summer, two of the three dams are still full of silt because of Cyclone Gabrielle in February.

“The water in the Clapcott and Williams dams is visibly murky (picture below) from multiple slips in the catchment and is too dirty to treat through the treatment plant’s sand filters.”

Mr Hadfield says to unlock the water stored in the Waingake Mangapoike dams, Council has already redirected water from the third and clean Sang Dam directly to the Waingake water treatment plant.

The next phase of the project is the installation of pre-treatment filters (lamellas).

Mr Hadfield says the filters will remove the silt and help restore the Waingake water treatment plant back to pre-cyclone flows.

“Our goal is to install the new filters by Christmas.”

This week residents will start seeing water conservation campaign which will continue over several months with predicted El Nino conditions likely to hit us soon.

Right now, the water being supplied to the city (and connected communities) is from the Waipaoa River and the Waingake - Te Arai River blended with a small volume from our clean Sang dam.

“All the water is fully treated and is safe for use.

“Council is still heavily in recovery mode, but this project will be another major step forward towards our district's recovery.”

  • Following the cryptosporidium outbreak in Queenstown the community might be wondering whether we are safe from these bugs.

Our water treatment plants have multi-barrier protection in place, so the risk is very low of this type of contamination from our water sources.

Picture below is the Waingake Treatment Plant. There are two clarifiers at Waingake, and lamellas are being installed one at a time so we can still produce water at Waingake, says Community Lifelines Acting Director Dave Hadfield. Picture by Gisborne Herald.

Waingake WTP - picture by Gis Herald

Clapcott, Williams and Sang dams