Selwyn district population expected to grow by 40 percent in a decade

Canterbury's booming Selwyn district could have a bigger population than a city such as Lower Hutt in a decade.

Selwyn's population is set to grow by about 40 percent in 10 years to about 120,000 residents, and surge to more than 160,000 people in 30 years.

The latest growth forecasts for the country's fastest-growing district were outlined at a Selwyn District Council briefing on Wednesday.

Council senior strategy planner Ryan Mayes said by 2055 Selwyn was projected to be about the size Tauranga is now.

"A huge chunk of the growth is coming to Rolleston and is projected to continue to do so. That is, another 15,000 residents in the next 10 years, 40,000 in the next 30 years," he said.

"By 2035 [Rolleston] will be about the same size that Nelson is now. 50,000 is kind of the classification for a city so Rolleston will be a city within 10 years. Then by 2055 we're getting up to sort of the size of Napier so really getting up there as one of the largest urban centres in the country almost."

Mayes said this extraordinary growth would require a huge amount of planning.

"For Rolleston we've got a huge amount of newly zoned land that provides for the short to medium term. We've got easily enough land already zoned for the next 10 years and it might be towards the end of the 30th year that we'll have a shortfall in housing and we'll need to look to identify growth areas to address that," he said.

Mayes said the council was not anticipating lot of growth in the smaller townships of Selwyn.

"There will be some in certain areas but it's not going to be something that needs a whole lot of work to look for new zoned land, maybe a little bit of industrial in some small places but apart from that," he said

On Tuesday Selwyn District councillors adopted the district's annual plan, confirming an average weighted rates increase of 4.5 percent.

However, the average rate increase is 8.8 percent for households connected to Selwyn Water Limited water services, once an 18 percent increase in drinking and wastewater charges is factored in.

The plan includes an $86 million capital programme, ongoing investment in water and wastewater projects delivered by Selwyn Water and increased investment in land drainage.

Mayor Lydia Gliddon said Selwyn's rapid growth continued to create pressure on key infrastructure.

"Selwyn is growing quickly, and with that comes real pressure on roads, water and community facilities. Our job is to make sure we're planning ahead and delivering in a way that sets us up well for the future," she said.