Constraints on the wastewater network could make it difficult to enable more intensive housing development in some parts of eastern Christchurch.
“We’re going through the process of changing our District Plan to enable more intensive housing development, as we are required to do by both the National Policy Statement – Urban Development and the Resource Management (Enabling Housing Supply) Amendment Act,’’ says Jane Davis, General Manager Infrastructure, Planning and Regulatory Service at Christchurch City Council.
“In most residential areas of the city, we are going to enable medium-density housing. That means people will be able to build up to 12 metres (usually three storeys) high, and up to three houses per section, without requiring a resource consent.
“We have the infrastructure – the water and wastewater pipes - in place to accommodate additional housing in most parts of the city, but there are some areas where we are concerned that we do not have the capacity to service more homes.
“This is the case in Shirley, Aranui and Prestons where we have a different wastewater system in place than in the rest of Christchurch. The three suburbs had vacuum sewer systems installed after the earthquakes because they deal better with liquefaction and land settlement,’’ Ms Davis says.
“The vacuum sewer pipes in Shirley and Aranui were designed for the intensification allowed at that time and have reached capacity, meaning only like-for-like development can occur. In Prestons, any development must align with a master plan for the area and developers should talk to us about what can be accommodated.”
Increasing the capacity would require the replacement of the main vacuum sewer pipes and an extensive upgrade or addition of vacuum sewer pump stations, at considerable cost.
That work is not part of the Council’s 2021-31 Long Term Plan.
The plan change proposes the infrastructure constraints in Shirley, Aranui and Prestson become ‘Qualifying Matters’, which would justify an exemption from the amount of increased housing enabled by legislation.
“Regardless of this becoming a Qualifying Matter or not, this is an issue that anyone considering building in those areas needs to be aware of,’’ Ms Davis says.
She says the Council understands it needs to plan for future growth and it is always looking at what infrastructure is required to support new development. Every three years it reviews its Infrastructure Strategy as part of the Long Term Plan process.
“We are continually measuring and monitoring capacity for our wastewater, stormwater and drinking water systems. As we identify areas with constraints, we can then prioritise these for upgrades through the Long Term Plan and Annual Plan processes,’’ Ms Davis says.
“Our message to residents is please come and talk to us early if you are planning to develop so you are sure you will be able to connect to our water or sewer systems.
“This is especially important as we follow Government direction and enable more houses to be built in the city to cater for our growing population.
“We have dedicated processes and resources in place to respond to Three Waters capacity queries and to advise developers on what local infrastructure upgrades may be needed as part of their development proposal.’’