As the planet continues to cook, extreme weather events like those we experienced over the last two weeks are set to become more frequent. How we plan our cities to mitigate the risks of climate change will inevitably be more salient going forward, and that will only increase over time.
Sadly, Councillor Lee (despite being conspicuously absent throughout the weather even) has teamed up with Councillor Fletcher to politicise the floods, in an early attempt to hijack this conversation to stop housing development in the richer “special character” areas of the city.
Two Auckland councillors are calling on the Government and National to rethink their plans for greater intensification after the city’s infrastructure shortcomings were exposed in the flood disaster.
Despite the pair having been among the most opposed Councillors to the Unitary Plan, Fletcher is lamenting:
“We must stop those who are determined to foist more and more housing in Auckland, well in excess of the provisions of the Auckland Unitary Plan. Their plans are flawed. Auckland cannot cope now.”
The unfortunate reality for advocates of this theory is:
- Recently intensified parts of the city fared better than most in the recent flooding
- The path forward for water-proofing the city involves building a lot more housing on top of other housing, not on top of bare land (or, god forbid, on flood plains)
- Much of the existing Unitary Plan is permissive to intensive housing in flood-prone areas, while the changes mostly affect drier suburbs
This is how density preserves green space. pic.twitter.com/kJnFeZjVnA
— Matt Prasad (@matty_prasad) May 3, 2019
It’s silly to say but important to note: neither more people nor more houses in an area will make it rain more. What does affect flooding is whether stormwater is managed on-site or left to be “run-off”.
Fortunately, the Enabling Housing Supply Act does not get rid of stormwater management rules. All new residential developments under the MDRS will have to include a landscaped area no less than 20% of the site.
More importantly, changing the default rules from permitting 2 stories everywhere to 3 stories will mean that up to 50% less land area will be required to meet both the city’s historic housing deficit and future growth needs.
Of course, new housing should not be built in flood-prone areas. But as the National Party’s housing spokesperson Chris Bishop notes in the Herald article, the legislation explicitly allows for exemptions to the ‘three over three’ direction in places subject to a range of natural hazards:
“The bipartisan Housing Supply Act provides councils with the power to exclude areas from further development if they are prone to a natural hazard, such as in an identified flood flow path. The responsibility is on councils to use the powers they were given to ensure intensification is only occurring in places where it is safe to do so,”
This is a good step, but doesn’t go far enough. Flood-prone areas are poor locations for residential development of any density. Council (likely needing support from central government) should rapidly roll out a plan to purchase land with houses damaged by the recent floods, to turn it into stormwater-resilient parks similar to Te Auaunga.
This would work to provide financial support to affected communities (avoiding the decade of insurer litigation as seen after the Christchurch earthquakes), while also preparing us for the next storm, and providing local amenity for the residents of the area.
Of course, avoiding building in gullies is necessary but not sufficient for adaptation. Water will continue to roll down hills and through any structures that happen to be in the way. We can fight this with rainwater gardens and effective drainage, but it is likely that our best efforts will always fall short of keeping everyone dry.
In this situation, our historic approach to urban planning (that is, paving over every inch of the city with homogenous 1- and 2-storey suburbia) leaves every home in the city vulnerable to flooding. In contrast, a city of apartment buildings would only see ground-floor units severely affected.
But in any situation, the changing climate now demands that we need vastly more stormwater investment. From a planning perspective, what matters is how we can shape the coming intensification to get the most of out of that investment.
As with all horizontal infrastructure, more people living somewhere equals more taxpayers and ratepayers across whom to spread the cost of infrastructure – and at the same time, compact cities allow us to serve more people with the same piece of infrastructure. This combination is why extremely populated and compact cities such as Tokyo can build such grand stormwater infrastructure.
In fact, Watercare’s core funding comes from both development contributions and water rates. More development bringing more people will necessitate more water infrastructure funding. There isn’t a trade-off between intensification and stormwater protection, it’s all or nothing.
Header image: Part of the Te Auaunga/ Oakley Creek Restoration Project through Wesley/ Mt Roskill, where the awa has been re-naturalised to reduce flooding impacts and improve ecological outcomes.