TAKING STORWMATER in AUCKLAND to a NEW LEVEL Phil Jaggard, Dukessa Blackburn-Huettner
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TAKING STORWMATER IN AUCKLAND TO A NEW LEVEL Phil Jaggard, Dukessa Blackburn-Huettner When Auckland Council became a unitary authority through the amalgamation of one regional council and seven territorial authorities, the management of stormwater in Auckland began its transformational journey. Following the initial creation of the Auckland Council Stormwater Unit (SWU) on 1 November 2010, the past four years has seen the SWU: • Create the SWU’s vision of a ‘water sensitive community’ • Build awareness - Water Sensitive Approach • Implement a structural realignment • Align internal processes and procedures • Consolidate data and information • Working collaboratively with the suppliers in ‘the way we work’ • Align and repackage all major operational contracts • Define roles and responsibilities with other council departments and Council Controlled Organisations (CCOs) The SWU is a key contributor to the Auckland Council’s vision for Auckland being ‘the world's most liveable city’ and the transformational shifts identified in the Auckland Plan. While significant progress has been made by the SWU since integration, there are still a number of challenges and opportunities to take stormwater management in Auckland to the next level by: • Defining regional levels of service within funding limits • Deliver stormwater infrastructure to service special housing areas in coordination with other major Auckland infrastructure providers • Optimise human resources through changing workloads, by balancing internal staff numbers with external consultants and contractors, to deliver best value for money • Define and enforce public vs private responsibilities in managing stormwater • Maximise environmental outcomes through collaboration This paper will provide an overview of how far the AC SWU has progressed as well as the challenges, opportunities and priorities propelling stormwater management to the next level, thereby contributing to the delivery of ‘the world’s most liveable city’. Keywords: Stormwater, Infrastructure, Auckland Council The catalyst of this transformational journey Introduction was the amalgamation of one regional council Stormwater management in Auckland is on a and seven territorial authorities into Auckland transformational journey from relying solely on Council and seven Council Controlled hard engineering solutions (e.g. pipes and Organisations (CCOs) on 1 November 2010. culverts) to the use of green infrastructure and The management of stormwater in Auckland, retaining natural stormwater systems that though simpler since the integration, still utilise innovative water sensitive design to presents a number of challenges; the achieve optimal environmental social and amalgamation, the complex nature of economic outcomes for Auckland. stormwater, and the number of entities involved • Create the SWU’s vision of a ‘water with the multiple contributors and sources. sensitive community’ Under the 2010 amendment to the Local The task of aligning eight different Government Act 2006, Auckland Council is organisations stormwater services into not only responsible for the following two activities: a single entity but also across two CCOs (AT and WSL) presented a number of challenges • Stormwater Management including aligning strategic directions and defining roles and responsibilities. However, • Flood Protection and Control. amalgamation presented new opportunities for In Auckland, the core public stormwater collaboration and optimisation of activities for services and assets are managed by the the greater good of Auckland and to support Auckland Council’s Stormwater Unit (SWU). In growth and development. addition, the management of stormwater is Each of the previous legacy Council’s had their closely linked to Auckland Transport’s (AT) own unique stormwater challenges, with activities and assets; and to a lesser extent variations in stormwater management Watercare Services Limited (WSL) and approaches and priorities. Each Council had Auckland Council Parks department. Many of differing challenges, business processes, the SWU’s treatment and detention facilities knowledge, expertise, District Plan rules, and overland flow paths are located in shared design guidelines and historic pipe design open spaces within Parks. capacity standards, including differing AT’s assets include the roads and associated approaches to flooding and climate change. drainage that both carries stormwater and For example, the Manukau’s stormwater connects to the core public stormwater system. system is comparably young in relation to In addition, roads are one of the highest Auckland City’s stormwater network with a sources of stormwater contaminants in urban focus on expansive growth in new greenfield runoff. areas. Historically Manukau City designed WSL owns and operates the combined sewer stormwater pipes to convey only a 1 in 5 year network that services approximately less than ARI storm event with a designated overland 10% of the former Auckland City area, and flow path, compared to Auckland City’s designs includes WSL’s controlled overflows into the requirements of 1 in 10 to 1 in 100 ARI year core stormwater system. storm events. Since amalgamation, the SWU has made The former Auckland City area is significant progress in improving the predominately fully developed with very few management of core public stormwater greenfield areas and growth occurring services. predominately by intensification. In addition, the former Auckland City area contains the These improvements include: oldest by age stormwater networks with some brick stormwater lines that require more • Aligning and repackaging all major frequent inspections due to their criticality and operational contracts risk of failure. • Aligning internal processes and procedures There are also differences in stormwater management approaches caused by the • Define roles and responsibilities with underlying geology of an area. For example, other council departments and Council soakage was used in place of a piped network Controlled Organisations (CCOs) in areas of Auckland City above basalt • Implement a structural realignment aquifers. In Papakura District areas with peat soils required infiltration solutions during • Consolidate data and information development to maintain ground water levels to • Build awareness prevent long term settlement. • Working collaboratively with the suppliers in ‘the way we work’ Creation of the SWU’s vision of a ‘water As more people become aware of the state of sensitive community’ the environment, the effect of land use on water bodies and the predicted effects of Stormwater in Auckland is an integral part of climate change and global warming, level-of- the three waters (water supply, stormwater and service expectations are beginning to rise while wastewater) that Auckland Council directly and maintaining low rates, driving changes to the indirectly influences. Largely invisible to way stormwater is managed. Aucklanders on a day to day basis, it does not form part of their consciousness, until either a The Auckland Plan is the strategic guide for large storm hits the city or when people interact Auckland’s future over the next 30 years. The directly or indirectly with water bodies. Auckland Plan puts forward the vision for Auckland to become ‘the world’s most However, Aucklanders have an expectation of liveable city’ by 2040. The Auckland Plan clean and health harbours and streams - the describes outcomes needed to achieve this life blood of Auckland - and stormwater can vision by 2040, highlighting six transformational cause much distress in times of flooding. shifts where a ‘step-change’ is needed, refer to Figure 1 for more details. Figure 1 – Auckland’s Vision Two of the six transformational shifts – The seven objectives will: ‘radically improving the quality of urban living’ and ‘strongly commit to • Support the vision of the SWU environmental action and green growth’ – directly relate to the provision of stormwater • Guide expenditure over the short, infrastructure. The investment and medium and long term management of stormwater has the potential to • Contribute to the delivery of the regional drive change across environmental, economic outcomes and social outcomes and freshwater is integral to a liveable city. As part of the SWU’s • Ensure good quality built and green commitment to the Auckland Plan the SWU infrastructure for present and future has set itself a vision: ‘To be a liveable city generations. we need to achieve a Water Sensitive Community’. In achieving the seven objectives, the SWU will give effect to the principles of the Auckland To focus the SWU business on achieving the Plan’s strategic direction, transformational above vision, the SWU has established three shifts and outcomes as shown in Figure 3. core and four supporting objectives. These objectives are strongly connected to Auckland Plan transformational shifts and strategic directions, as shown in Figure 2. Figure 2 – SWU’s Vision and Objectives Build awareness - Water Sensitive • Commit to water sensitive and low Approach impact design during new development The concept of ‘Water Sensitivity’ is a shift in and redevelopment of land which the focus of stormwater management from promote at source treatment and mimic removing or disposing of stormwater as fast as predevelopment hydrology. possible via built infrastructure, to recognising the value of stormwater, its close • Maintain and enhance the health of interrelationship with natural freshwater streams, groundwater and coastal