12 Mar 2021

Protecting and upgrading our water networks is one of our key areas of focus for our capital expenditure.

One of the Council’s core responsibilities is to provide and maintain the wells, pipes, reservoirs, treatment plants and pump stations for drinking water and manage the collection, treatment and disposal of wastewater and stormwater.

This infrastructure is essential to the health of our city and our residents. It contributes to the health of our rivers, streams and harbours and it is the most costly service we provide. The capital cost of water infrastructure and services accounts for 41 per cent of our proposed capital spending for this Draft Long Term Plan.

Many of our water supply pipes are ageing and vulnerable to leaks – modelling shows that leaks have increased by a third in the past two years and we lose the equivalent of 90 Olympic-size swimming pools each week. We need to renew more of our pipes to reduce our leakage rates.

Over the next few years, the way councils provide water services to people is going to change. We’re part of the conversation with the Government, and we’re talking to iwi and neighbouring councils about the future of our ‘three waters’ services – drinking water, wastewater and stormwater. There will be a public consultation process later in the year.

Surface water and waterways

We’re committed to maintaining the health of our waterways across our district, and to working with our communities to reduce the pollutants that can enter our urban streams and rivers.

Our focus will be on delivering the floodplain management and stormwater quality elements of the Ōtākaro Avon River Corridor work programme.

We propose spending $695 million on infrastructure over the next 10 years, including:

  • Implementation of Ōtākaro Avon River Corridor Regeneration Plan. A major part of this is temporary or permanent stopbanks work ($86million).
  • New or retrofitted stormwater treatment facilities ($369 million).
  • Renewing and replacing pump stations, pipes, drains, swales, waterway linings ($240 million).

Wastewater

Our main focus will be on replacing poor condition wastewater pipes. Much of our wastewater network is old and leaky, and lets large amounts of groundwater and stormwater into the wastewater system. These pipes are also prone to blockages. Both of these factors can lead to increased overflows of wastewater to the environment, which creates a public health risk and isn’t good for the environment.

We plan to protect the Lyttelton and Akaroa harbours by removing treated wastewater discharges from them. In 2021, wastewater discharges from three wastewater treatment plants in Lyttelton Harbour will stop, and all wastewater will be pumped to the Christchurch wastewater treatment plant.

Akaroa’s current wastewater treatment plant and outfall are in a culturally and historically sensitive place and they are old and need to be replaced. We plan to build a new modern treatment plant and use the reclaimed water to irrigate new areas of native trees in Robinsons Bay, Takamātua and Hammond Point.

We plan to use some of the reclaimed water for irrigating public parks and flushing public toilets in Akaroa. We will also work with Ngāi Tahu, government agencies, and other water suppliers to develop regulations to allow the use of this water on private properties for irrigating gardens and flushing toilets.

In Duvauchelle, we are also exploring removing the treated wastewater discharge from Akaroa Harbour, and irrigating it to land instead, possibly on the golf course. This would mean an end to treated wastewater discharges to Akaroa Harbour. We will be consulting on the options for Duvauchelle later in the year.

We propose spending $798 million on wastewater infrastructure over the next 10 years, including:

  • Removing treated wastewater discharges from Akaroa Harbour ($69 million).
  • Replacing or renewing ageing or damaged assets that are in poor condition ($626 million).
  • New or retrofitted wastewater reticulation and treatment facilities ($103 million).