Biophysical Limits On Cities
In a recent New Zealand Herald article on the Auckland water crisis Simon Wilson identifies 18 contributory factors including lack of strategic planning, lack of political direction, climate change, ignoring advice, and yes of course lack of rain. You could add that Auckland is in the wrong place.
In its origins as a port town, it was in the right place. Then as it grew and became a city with ports, economic and population growth stretched the infrastructure. It is true that good planning would have reduced the problem of ensuring water supply, but the fundamental problem is that the city is naturally water-constrained. This was clear in the 1980s and ‘90s, reinforced by predictions that climate change will exacerbate the problem.
Economic growth models promote urbanisation as being key to successful development, extrapolating from the town square model and the benefits of division of labour. Cities are efficient as business centres, generate innovative thinking, people like living in them, and they are key to increasing gross domestic product. What gets lost in the enthusiasm for supporting measurable front-of-house economic growth is the back-end biophysical constraints.
That we are tapping the Waikato River to keep Auckland going is an indicator that the city is living beyond our means. Using the Waikato started in 2002 as a top-up, and now has become a vital life-line. This year, a third of the city’s water is from the Waikato due to the drought. Such droughts may become more common. Having to take a resource such as water from a separate set of catchments to subsidise overuse in our own catchments is a warning. Auckland needs to augment its glossy front-cover efficiency with the more prosaic message that the city is water-constrained.
We could become more water-use efficient. This includes exploring the pros and cons of requiring residential and commercial builds to include water tanks. It may be more cost-effective for ratepayers to support on-site collection and use for non-potable purposes than increase the capacity to pump and treat more of the Waikato, or build more dams. It would also make the city better able to manage dry periods by creating a distributed water storage system to augment the centrally managed one. Also needing to be explored is the use of on-site sewage treatment including composting toilets. Some of these options could be retrofitted.
There are direct and indirect costs for developers and property owners in putting in water storage, efficient water use technology, and on-site sewage systems. Given the benefits of doing so are spread across the community, the full costs should not be borne solely by those developers and property owners. The capital cost repayments should be spread over time and covered by all those benefiting.
Water storage would also fit with the Auckland Council’s Water Sensitive Design for Stormwater which promotes on-site water retention (among other things) to help reduce run-off. This helps improve water quality and manage flow rates, and retained water could be used on-site. It will also contribute to achieving water management goals under the National Policy Statement for Freshwater Management – a legal requirement all councils have to work with.
Ultimately Auckland Council also has to consider there are limits to growth, in terms of population and water use associated with commerce and industry. While land constraint has been the focus, water constraint is equally if not more pressing. Incentivising the relocation of business and employment out of Auckland needs to be pursued to distribute the load.
Cities finding themselves in the wrong place is a common problem globally. Think of a coastal city and most will be coping with too much water, too little, or a combination of both. As climate change bites, seriously hard decisions need to be made. Auckland has delayed making these decisions. The drought should trigger a review of how the city manages its water constraint in the long term.