By Ed Clayton. Part 2 of a 3 part series
Welcome to the second post in this three-part series. This instalment investigates the concept of the Water Sensitive City – an idea that has been gaining traction internationally over the last 20 years. It will cover how Auckland has been taking steps along the path towards this concept and how the updated National Policy Statement for Freshwater Management may influence our collective freshwater resource in the near future. The first post looked at the historical relationship Auckland has had with freshwater, the third post will look at the current transport paradigm in Auckland and how transition to a low-carbon rapid-mass-transit system could provide tangible water quality benefits.
As seen in the first post, urban areas have historically had rigid interactions with freshwater. Natural freshwater systems are degraded due to urban activity. Clean water is delivered for domestic purposes and waste is transported away, usually through a centralised agency, be it publicly owned or a private entity. Rainfall is generally regarded as a nuisance, to be removed through piped networks and modified stream channels.
This ‘command and control’ approach is now recognised as being detrimental to the environment. A response emerged from Australia, in the 2000s, as the ways cities interact with water were reimagined. A conceptual framework was created that recognised that the relationships cities have with freshwater exist on a spectrum of service delivery functions and socio-political drivers1. This ‘urban water management transitions framework’ recognises the changing dynamics that occur between social, pollical, cultural and economic realms as cities pursue a sustainable future. At one end is the city of the early industrial age, where the supply of clean drinking water was the primary concern. The city progresses through stages as it grows and evolves through time, with the addition of sewers, flood protection, environmental protection and amenity until we reach the concept of the Water Sensitive City, the future state of a sustainable city’s relationship with water. As described in the first post in this series, this reflects a change in the ecosystem services that we value.
The concept of Water Sensitive Urban Design is integral to this. The entire water cycle is acknowledged at the initial stages of infrastructure design. How can infiltration be achieved so that streams have similar baseflow conditions pre- and post-development? How do we attenuate the runoff from impervious surfaces like concrete so that we don’t exaggerate flood peaks? Planting of rain gardens, tree pits and swales can provide for uptake of pollutants, amenity and also reduce the urban heat island effect2. Reducing direct surface runoff and promoting infiltration can help reduce the need for large pipe networks. Effective ‘green’ infrastructure hides its function within its aesthetics. People may see a grassed and planted area that resembles a park, yet not know that the primary functions are provision of stormwater retention, pollutant removal and infiltration.
Auckland Council has invested in research into areas such as green roofs3, stormwater contaminants4, surface runoff hydrology5,6 and bioretention devices7. Popularising this research and promoting appropriate infrastructure is critical, and Water Sensitive Urban Design practices are being adopted by Auckland Council8. Biofiltration devices such as raingardens and swales are commonplace in newer urban developments. Permeable pavements are increasingly being used in low traffic environments such as parking bays. Stream restoration has taken place in numerous catchments, noticeable examples are Lucas Creek in Albany on the North Shore9 and the Twin Streams work being done in Henderson in conjunction with community efforts10. New developments are required to try and achieve ‘hydrological neutrality’ through measures that attenuate runoff from impervious surfaces to reduce flood peaks and ensure that the pre- and post-development characteristics of a stream are the same. Whatever else you may think of the Albany mega centre, it has a swale treatment system on the north side of Civic Crescent that hides in plain sight.
A swale at Albany Mega Centre. Water drains from road surfaces underneath the footpath to the grassed swale, the catchpit in the photo serves as the swale overflow point during heavy rain. Photo: E Clayton
The Long Bay development has invested in different infiltration devices, permeable paving and stormwater retention with significant aesthetic components. There will always be discussion around the suitability of low impact design devices and stormwater infrastructure, but compare the Awaruku Stream above Long Bay with the retention wetland built. What would you rather have in your backyard?
However, the Water Sensitive City is more than just good urban design and a revamped approach to water consumption11. Water is treated as a resource, and the needs of our descendants are taken into account. Our interactions with freshwater need to be carefully managed so that we do not harm streams so that future generations cannot enjoy them. Cultural water values are respected. Communities have important roles as partners, great examples are educating kids about the macroinvertebrates (bugs) that live in streams and using kids to change parents’ perceptions of freshwater and identity. Some of my strongest childhood memories are trying to find koura and inanga in streams, building boulder dams in a nearby creek and jumping off bridges in summer. Building a relationship with a freshwater resource makes a stream more than just a physical location, it becomes a ‘place’ and delivers a sense of identity. We need not look further than the concept of māuri and, I would suggest, return to a decision making process that involves participation of communities, iwi and government to create places within our city that adequately understand and relate to freshwater.
There is some progress towards this. ‘Daylighting’ of streams has been done in Auckland and overseas (where streams that were once piped are dug up and returned to a closer approximation of natural conditions). Interactions between people and these reinstated freshwater ecologies has been encouraged. Community planning and planting days were recognised a key facet in the successful La Rosa stream daylighting project in West Auckland12. Seoul saw the successful removal of a major expressway corridor and daylighting of the Cheong Gye Cheon, which has proved to be a popular destination for tourists and residents and experienced an increase in biodiversity as well13. While the nature of these two projects is different (La Rosa is stream restoration, Cheong Gye Cheon is urban regeneration), the share one common theme: the orientation of a public space towards freshwater.
Encouraging community groups and residents to participate in decision making about the future of urban streams must happen if we are to have more successful rehabilitation projects. If the vision of the Friends of Oakley Creek Te Auaunga could be realised, we could have a 15km long green network running through our city that provides a valuable ecological space and wildlife corridor14. As part of flood protection works in the catchment, Auckland Council has implemented new methods of engagement to achieve enhanced project and social outcomes15,16.
The newly updated National Policy Statement on Freshwater Management (NPS-FM)17 also recognises in principle the need to reduce contaminants, safeguard ecosystem services and improve water quality (I’ll leave aside the robust discussion about what will actually be done that this document has already generated). Specifically, while it may not go far enough in properly addressing urban issues, it mentions common urban contaminants such as sediment, heavy metals, litter and faecal contamination. It also recognises Te Mana o te Wai and requires this to be considered as an integral part of freshwater management. The Auckland Council has set up Wai Ora-Oranga Rerenga Wai18 in response to this, with the express purpose of implementing the NPS-FM and involving communities in doing so.
With the best current approaches and management of freshwater, there is evidence to suggest that once a catchment has been urbanised there will be a measurable impact on a stream19. All we appear to deliver is some level of mitigation for the impacts we have. This must change. If we want a sustainable freshwater environment, maybe we need to limit our urban expansion and instead concentrate on a city that looks to limit its footprint, both in physical and environmental terms. Our infrastructure must be developed, right from concept, to fit within the landscape not change it. The ecosystem services we value must be at the forefront of our planning. And we need to see our freshwater resource in front of us and interact with it. We need to be innovative, and this will involve communities, iwi and government working together guided by the concept of māuri. We are at the centre of the water hemisphere20, so why do we turn our backs on our urban freshwater?
Where do you think Auckland would fit on the transitions framework? Can you think of a stream in your neighbourhood that you would like to see restored?
Acknowledgements: Australia has done much to invest in the concept of the Water Sensitive City. A website well worth visiting is the Cooperative Research Centre for Water Sensitive Cities (watersensitivecities.org.au). Thanks also go to The Sustainability Society for hosting a webinar in September 2017 where Dr Briony Rodgers and Katie Hammer from the CRC for Water Sensitive Cities presented their latest research, tools and methodologies.
References and further reading:
- Brown, R.R., Keath, N. & Wong, T.H.F., (2009) Urban water management in cities: historical, current and future regimes, Water Science and Technology, 59(5), pp847-855
- Elmqvist, T., Setälä, H., Handel, S.N., van der Ploeg, S., Aronson, J., Blignaut, J.N., Gómez-Baggethun, E., Nowak, D.J., Kronenburg, J. & de Groot, R., (2015) Benefits of restoring ecosystem services in urban areas, Current Opinion in Environmental Sustainability, 14, pp101-108
- Fassman-Beck, E.A. & Simcock, R., (2013) Living roof review and design recommendations for stormwater management, Prepared by Auckland UniServices for Auckland Council, Auckland Council technical report TR2013/045
- Kelly, S., (2010) Effects of stormwater on aquatic ecology in the Auckland region, Prepared by Coast and Catchment for Auckland Regional Council, Auckland Regional Council Document Type 2010/021
- Shamseldin, A.Y., (2011) First Flush Analysis in the Auckland Region, Prepared by Auckland UniServices Ltd for Auckland regional Council, Auckland Council Technical Report 2011/007
- Mills, G.N. & Williamson, R.B., (2008) The Impacts of Urban Stormwater in Auckland’s Aquatic Receiving Environment: A Review of Information 1995 to 2005, Prepared by Diffuse Sources Ltd and Geosyntec Consultants for Auckland Regional Council, Auckland Regional Council Technical Report 2008/029
- Fassman, E.A., Simcock, R. & Wang, S., (2013) Media specification for stormwater bioretention devices, Prepared by Auckland UniServices for Auckland Council, Auckland Council technical report, TR2013/011
- Healy, K., Carmody, M., Bird, B. & Conaghan, A., (2010) Construction of Stormwater Management Devices in the Auckland Region, Prepared by Aecom Ltd for Auckland Regional Council. Auckland Regional Council Technical Report 2010/052
- Wong, T.H.F. and Brown, R.R., (2009) The water sensitive city: principles for practice, Water Science & Technology, 60(3), pp673-682
- Friends of Oakley Creek Te Auaunga; http://www.naturespace.org.nz/groups/friends-oakley-creek-te-auaunga
- Allpress, J.A., (2016) Te Auaunga Awa (Oakley Creek) social evaluation: report 1 – engagement, Auckland Council technical report, TR2016/041; http://www.knowledgeauckland.org.nz/assets/publications/TR2016-041-Te-Auaunga-Awa-Oakley-Creek-social-evaluation-Engagement.pdf
- Field, A. & Butler, R. (2017) Te Auaunga (Oakley Creek) social evaluation: social procurement case studies, Prepared by Dovetail for Auckland Council; http://www.knowledgeauckland.org.nz/publication/?mid=1382&DocumentType=1&
- National Policy Statement for Freshwater Management 2014 (amended 2017); http://www.mfe.govt.nz/publications/fresh-water/national-policy-statement-freshwater-management-2014-amended-2017
- Wai Ora-Oranga Rerenga Wai; https://www.aucklandcouncil.govt.nz/environment/looking-after-our-waterways/Pages/wai-ora-healthy-waterways.aspx
- Larson, T.A., Hoffman, S., Luthi, C., Truffer, B. & Maurer, M., (2016) Emerging solutions to the water challenges of an urbanizing world¸Science, 352(6288), pp928-933