Kāinga Ora - Homes and Communities is forging ahead with its bold plan of providing 40,000 new homes, of all types, over the next two decades in Auckland.
At the same time, it is making sure the reinvigorated state housing areas are resilient and flood-protected against adverse weather events.
The Auckland Anniversary Weekend downpour didn’t send the engineers scuttling back to the drawing board to redesign their land infrastructure systems.
“What it did do is give us a huge amount of up-to-date, real-world data, and we are going to get more accurate with our planning,” says Mark Fraser, Kainga Ora general manager urban development and delivery.
“Often, our infrastructure is based on theoretical engineering models but now we have actual data for a significant rain event. We can be more certain about what happens in the area if it rains hard,” Fraser says.
“What we saw in Northcote, Roskill South, Ōwairaka and Tāmaki was that the stormwater infrastructure we built coped very well and beyond the design standard.”
Fraser says the Auckland Anniversary rainfall was a one in-250-year event. “You can plan for anything, and we are making sure the infrastructure is capable of dealing with more frequent events in a non-disruptive way.
“We are designing for one in 100-year events and more. Māngere, for instance, was built in the 1960s and designed for a one-in-10-year event.”
As well as future-proofed infrastructure, Kāinga Ora considers the placement of homes. “We set a minimum level the house can sit at to manage the collection and flow of water,” said Fraser. “The height of the ground floor is designed to be above the level of flooding.”
Fraser says during the January downpour, residents in Northcote watched as the recently-completed Greenslade Reserve filled up like a giant basin, completely submerging the high-performance sports field and surrounding park amenities with 12 million litres of water in just hours.
Before the upgrade of the reserve last year, a less significant downpour would have flooded the neighbouring town centre and surrounding homes and streets. In less than 15 hours after the (recent) flood, the water filling the reserve had drained away, the retail stores had reopened for business and the fields were in use again, says Fraser.
The daylighting of the nearby Awataha stream (it had been underground and unseen for 70 years) also ensured water that would have previously put pressure on stormwater pipes was redirected through the stream channels. This meant homes on nearby Tonar St reported no damage during the flooding event, when previously water flowed beneath the houses during heavy rainfall.
Fraser says in Roskill South, the newly-completed Freeland Reserve provides stormwater treatment and mitigation for about two-thirds of the neighbourhood. The reserve is bolstered by three new floodwalls and the Te Auaunga Awa creek has been daylighted, or brought into the open, to allow a greater level of stormwater management.
“Freeland Reserve didn’t just do its job to hold back an extraordinary amount of stormwater. Additional design measures such as a spillway allowed water overflowing from the brim of the reserve to be channelled via an overland flow path onto roads rather than backyards.”
Across the motorway in Ōwairaka, there’s a $32 million shovel-ready project to separate the old stormwater and wastewater network and increase capacity.
Fraser says while rainwater could still be seen flowing down the streets on January 27, the planned overland flow paths ensured it drained quickly with very little damage in the previously flood-prone area, and none to homes.
“The Auckland Anniversary rainfall was well beyond most flood-modelling standards set to withstand current one in 100-year events. But this shouldn’t be a reason to stop what we are doing,” he says.
“The catastrophic flooding showed the reality of brownfield urban development in low-lying areas of Māngere, Mt Roskill and Northcote is much more complex than a simple ‘to build or not to build’.”
Fraser says climate change, a housing crisis and outdated, broken infrastructure buried in challenging land conditions like volcanic rock or boggy peat all present significant and often competing considerations for Kāinga Ora’s development teams to respond to.
“We cannot turn our backs on those communities. Current climate change models indicate extreme flooding events will continue to hit these communities more intensely, more frequently and more unpredictably in the years to come.
“Every year these neighbourhoods sit on outdated infrastructure, they become more at risk. We cannot allow nature to take its course and simply walk away. We must improve the resilience of our infrastructure to not only meet the current needs but also protect those communities in the future.”
Fraser says the kind of density and scale Kāinga Ora is planning in Māngere - 10,000 new homes delivered over the next 20 years - justifies the investment in future-proofed infrastructure.
“We are not just allowing for the infrastructure capacity of our Kāinga Ora homes, we are looking at the entire suburb, delivering better flood-risk protection to benefit all residents in the community. We are looking at renovating suburbs that are well-located with proximity to employment, amenities and transport. We are building modern, fit-for-purpose homes and ensuring a supply of affordable housing for the market.”
Fraser says the New Zealand housing market has been poor because of its focus on building the most expensive house it can sell. It has gone to the upper end of the market and created a gap between state housing and more expensive homes.
“We have not been good at building moderately-priced homes for the market and that has contributed to the recent housing affordability problem. We are using scale to drive a greater range of housing in type, size and price,” says Fraser.
“Some people may ask why we keep building thousands more homes on land that is prone to flooding. Much of the [initial] development was done at a time where flooding risk was not nearly as understood as it is today. We now have real data that we didn’t have previously.
“Where places are at risk, we now have a solution available, and we just need to get on with it. When you build at scale and do the job properly, it works well.”
State of play
Kāinga Ora is transforming old state housing areas in Auckland into modern, well-connected neighbourhoods and increasing the supply of affordable housing.
Current projects are:
· Northcote: Started in 2016 demolishing 314 existing state houses and replacing them with 1700 new homes including 480 new state homes, townhouses/duplexes/terraced housing and apartments. Land development work with improved infrastructure (roads and pipes) finished mid-year and house construction will continue for another two to three years.
· Mt Roskill encompassing Roskill South, Ōwairaka, Waikowhai and Wesley neighbourhoods:
Roskill South: 290 state houses replaced by 330 new ones and a total of 1000 homes will be built over next five years. Land development nearly finished.
Ōwairaka: 1200 new homes including 280 state houses replacing 225 old ones. Land development will be finished next year.
Oranga (Ōnehunga): most of the state houses were built in the 1940s on a suburban cul-de-sac masterplan, 1100 new homes will be built over the next eight years with 400 old state houses replaced by 500 new ones.
· Some 20,000 state houses were built in Māngere in the 1960s and Kāinga Ora owns more than one in five homes. Development currently involves Māngere West and Aorere, with five to seven years completion timeline.
Māngere West: 950 new homes including 340 state houses replacing 230 old ones. Aorere: 500 new homes including 160 state houses replacing 137 old ones.
· Kāinga Ora is working with the Tāmaki Regeneration Company to complete the country’s biggest inner-city urban development project on 900ha in the suburbs of Glen Innes, Point England and Panmure. Streets, parks and town centres will be upgraded and up to 11,000 new homes - a third will be state houses - will be built over the next two decades. Kāinga Ora is completing the land development work and building some houses. Construction is currently taking place in six neighhourhoods - Line-Epping, Hinaki, Overlea, West Tāmaki, Derna Tobruk and Dunkirk.