8 June 2017
Report to members
Three months after the idea of a coalition of community groups was first mooted, and two months since the Stop Auckland Sewage Overflows Coalition (SASOC) was formally established, it is time to report to you and seek your views on the emerging issues and SASOC’s proposed forward plan.
Who is in SASOC
Membership is open to all groups who share SASOC’s concerns about the presence of sewage in stormwater overflows in Auckland.
Several groups, representing communities that fringe the inner Waitemata harbour or are located in inland parts of the Auckland isthmus, initially supported the formation of the coalition and were invited to become members after it was established formally.
What has SASOC been doing
Auckland’s polluted stormwater overflows have been known to our city administrators for decades. The overflows occur predominantly in areas served by old infrastructure in which sewage and stormwater are carried in combined pipes. There is a lengthy history of localised separation and reactive maintenance. The fragmented approach to a solution for the old parts of the city, where the majority of the old combined pipes were installed, is a consequence of unwillingness on the part of our politicians to meet the cost of a comprehensive solution. The former Auckland City Council eventually adopted a policy of total separation, increased rates to provide for it, and allocated funds to the process. This has been shelved since at least 2010, following the formation of the super city, and the funding obtained from the rates increase has been allocated elsewhere.
SASOC initially approached the problem by applying the logic that if the pollution is primarily due to mixing of sewage and stormwater in the combined pipe system, and the overflows are essentially a consequence of surges of stormwater in periods of significant rainfall, the polluted overflows will largely be eliminated if sewage is separated from stormwater. As mentioned, this appears to have been the approach in the former Auckland City Council, even if it was slow to implement it – perhaps to spread the economic cost.
We started by trying to find out what those responsible for managing the problem are doing about it. We have met with senior management at Watercare Services Limited (which operates the combined pipe system and is responsible for disposing of the city’s wastewater) and at Auckland Council (its stormwater section, known as Healthy Waters, is responsible for managing stormwater in the city). We have also met with a project team drawn from those two bodies that was established last year to develop long-term strategies for stormwater and wastewater services in Central Auckland for Auckland Council’s 2018 long-term plan. This team is known as CANOPy, standing for Central Auckland Stormwater and Wastewater Network Optimisation Programme.
We have also spent considerable time researching initiatives taken overseas to address the same problem. Historically many cities around the world built combined drainage infrastructure, and are also now having to find ways to remedy its deficiencies. More recently we have been liaising with other community and environmental groups here in Auckland who are active in seeking improvement to Auckland’s water quality issues.
Currently most of this work has been undertaken by SASOC’s co-convenors. There will be a lot more to do in the coming months. The co-convenors are keen to establish a wider working committee drawn from our membership – to date one member (Orakei) has offered to take an active part – particularly drawing in scientific and engineering knowledge and communication skills.
Activity in the wider community
As already mentioned briefly, many of the current issues have had a long history, including effective involvement of community groups. Several iwi and environmental groups (too numerous to mention here by name, but many of whom took part in very recently in a Manukau Harbour Symposium) have been working for years to improve the quality of water in the Manukau Harbour – and, understandably, have a strong interest in water flowing into that harbour, just as we have in waters flowing into the Waitemata.
Other groups (such as St Lukes Environmental Protection Society, Friends of Oakley Creek and the Whau River Trust) share the wider concerns but have specific interest in inland waterways flowing into the Waitemata such as the Meola creek, the Oakley creek, and the Whau river. All of these have been heavily polluted in the past, and are improving due in significant part to the work of these groups.
Where SASOC differs from the other groups
Whilst SASOC recognises the need for an Auckland-wide solution to water problems, our primary focus is on the elimination of sewage polluted overflows into the Waitemata. However, we also recognise that this should not be done by shifting the problem to another part of the city – which is, in effect, what happens if all water from the central Auckland isthmus continues to be carried in mixed form to the Mangere treatment plant. This is the reason that SASOC is determined that separation of the combined pipe system should remain on Auckland Council’s agenda for the 2018 long-term plan.
There will still be need for treatment of stormwater carried in a separated system (for example to deal with pollutants collected off our streets and in overland flows). But the research that we have seen to date suggests that it is possible to treat this locally. The treated water could possibly be discharged directly into watercourses such as Cox’s Creek and then into the Waitemata rather than moving it to Mangere for treatment, as remains the case with wastewater.
By comparison, the Manukau Harbour groups are concerned, understandably, about the current focus of water management authorities on conveying all water to Mangere for treatment, and thus the volume of the total discharge into that harbour.
What has SASOC found to date
The problem of overflows has been ongoing for many years. In 1989 the then Auckland City Council commenced planning for a large collector pipe (known as the Central Interceptor) to run between Western Springs and the Mangere treatment plant. This is intended to increase the capacity of the predominantly combined pipe network in central Auckland so that it would cope with the amount of stormwater entering the network in periods of significant rainfall.
However, although this pipe will improve the holding capacity of the network, it will not necessarily eliminate overflows from parts of the system flowing into it, or the pollution that is a consequence of combining stormwater and sewage. Apparently the combined system needs an overflow “safety valve”. Thus overflows can never be entirely ruled out. What is concerning though is that overflows are happening even in light rain (ie more than 5mm), and one site is overflowing about 100 times annually (the overflows have been estimated at 2.2 million cu metres annually in 2015).
Various false starts and regular expenditure reprioritisations delayed implementation. In the next couple of decades the Auckland City Council began a long term program to separate wastewater and stormwater. This has resulted in the combined pipe network being replaced by separate stormwater and sewage networks in several areas, and a substantial number of properties having their storm and wastewater separated to their boundaries, either directly by Council (in Pt Chevalier, Waterview, Kingsland, Westmere, parts of Grey Lynn and Orakei) or indirectly as a result of building requirements for redevelopment and/or larger scale property upgrades.
Unfortunately, in most cases, this separation has had no impact on overflows because unless separation had been undertaken in the street, both the now separated stormwater and wastewater pipes on private properties still connected to the combined pipe network. For that separation to be effective it the stormwater pipes needed to discharge to a designated stormwater-only network.
After the formation of the supercity, Auckland City Council’s previous separation program ceased (with a few exceptions), and the Central Interceptor project was further deferred. Construction is now projected to start in 2019 with a completion date of 2026.
Many overseas cities have underground combined networks (bear in mind that this system was revolutionary when it replaced the previous open drain system!). The USA, UK, and Canada have many cities with significant combined systems. Many of these have had very significant environmental degradation caused by overflows and have had similar experiences in tackling them: substantial upgrading expenditure was required for recovery and councils were reluctant to initiate the required expenditure – meaning that progress was pedestrian.
In all these jurisdictions central governments banned overflows of untreated sewage and introduced regulators to force faster compliance with new water purity standards.
Many of these cities (eg London) already had intensified urban populations. Many buildings had party walls and covered the entire site. This made it impossible in many cases to separate the wastewater/sewage without excavating underneath these buildings. These cities have made improvements by a series of mitigation measures. These include a combination of separation (where possible), reducing stormwater inflows by local collection and treatment, introducing permeable footpaths, constructing stormwater holding tanks/ponds, and other innovations. In some cases it has been possible to reduce overflows by up to 98%, while others have not been as successful.
The legal position on overflows
SASOC has sought the views of a senior environmental law expert about the legality of the overflows. Our understanding is that, as a starting point, overflows from the combined system are unlawful under the Resource Management Act. However, there is a provision in that Act for existing use rights. We understand that Auckland Council relies on existing use rights to continue a system designed to allow overflows as a safety valve. These existing use rights continue in perpetuity. Significantly, however, any new overflow infrastructure is a Restricted Discretionary Activity under the Unitary Plan, which will require resource consent.
Limitations of the Central Interceptor project
The Central Interceptor project will mitigate overflows in its immediate (inland) catchment, but it appears to be of limited or no assistance in other catchments, particularly those that flow naturally to the Waitemata, without further work being done to link it to collector pipes in those other catchments. For that reason it will not have much effect on the Western Bays and Orakei/Parnell outfalls. SASOC understands that a similar major collector planned for the harbour catchments (the Waterfront Interceptor), which will join to the Central Interceptor, will be required to relieve overflows in the Western Bays catchment. Further, a Remuera Interceptor may be required for the Parnell and Orakei catchments.
Shared responsibility for the problem
Responsibility for water management in Auckland is shared between Auckland Council and Watercare: in very general terms, Watercare is responsible for supplying our potable water and collecting and treating our wastewater; and the Council (Healthy Waters) is responsible for collecting and disposing of our stormwater.
To carry out these functions, they manage the separate networks of pipes and associated infrastructure that collect and carry the waters for which they are responsible. Where stormwater and sewage are carried separately, the infrastructure is managed by whichever one is responsible for that water. Where the two waters are collected and carried together (as in the older parts of Auckland) Watercare is responsible for managing that combined pipe network, even though it also carries stormwater.
However, although Watercare is responsible for the management of the combined pipe network, it is not financially responsible for any stormwater upgrades to that system (as distinct from wastewater upgrades).
Both Auckland Council and Watercare are legally obligated (under the Local Government Act) to have a management plan to ensure sustainability of important infrastructure assets. This requires provisioning (depreciation) for the eventual replacement of the assets.
Auckland Council’s current stormwater management plan is set out in a publicly available document named “Stormwater Asset Management Plan 2015 – 2045”. It provides a broad overview (no doubt being a composite of the plans of the various amalgamated councils) but lacks a specific action plan, including the financing of the plan.
What it does show is that Healthy Waters regularly values its stormwater assets, using two methodologies – Optimised Replacement Cost (“ORC”) and Optimised Depreciated Replacement Cost (“ODRC”). The latter figure is the assessment of the depreciation required to allow for wear and tear. Council values its ORC as $5.4 billion and ODRC at $4 billion, an asset depreciation of some $1.4 billion. The critical question in SASOC’s view is what Council is doing to fund this difference.
Auckland Council’s annual accounts do not specifically disclose what funding is available for the replacement of stormwater assets. We suspect there is a significant shortfall. Some of the older parts of Auckland such as Parnell and Freemans Bay will be getting close to the 125 year life expectancy of their underground infrastructure and may be due for imminent upgrading. This is an important factor in any decision about whether to continue to separate the combined pipe system – the optimum method for eliminating sewage overflows. Approaches have been made to Council for elaboration on this issue.
Watercare’s plan is in a document named “Asset Management Plan 2016 – 2036”. The significant items in the Watercare plan for the overflow issues in central Auckland are, as noted above, the construction of the Central Interceptor, and contemplation of a second such pipe (the Waterfront Interceptor) to carry both stormwater and wastewater. However, it makes clear that there will also need to be for further work linking the Central Interceptor to existing networks.
The CANOPy project
This joint venture team was set up as a result of Mayor Phil Goff’s request for a “three waters” report. It is developing an integrated approach to the provision of stormwater and wastewater services in the central Auckland area (where the combined pipe network is located). The team is to report back to Council in about a week (by mid-June). It operates under a set of guiding principles, the most important of which are:
• There is to be a fair and equitable sharing of costs between Council and Watercare.
• Services are to be maintained at “optimal economic levels” (without stating what that means).
• Watercare’s network discharge consents (for discharges from the Mangere treatment plant) must be complied with – this requires Watercare to demonstrate that the network meets wet weather overflow criteria.
• The combined pipes are not for flood mitigation. The fact that stormwater enters the combined pipe network does not obviate Council’s responsibilities for providing stormwater services in the combined sewer areas.
• Recommended solutions will be supported by robust technical evidence with a reasoned business case for the preferred approach.
• The integrated stormwater and wastewater strategies will be formally and regularly reviewed by the parties to ensure currency and agreed progress from decade to decade.
The CANOPy agreement lists several areas for “catchment optimisation”: St Marys Bay, Herne Bay, Cox’s Creek Edgars Creek, Motions Creek, Westmere, Lower Meola Creek/Pt Chevalier, Upper Meola Creek, Haverstock Catchment, Lyon Catchment, Oakley Creek, Whau Creek and Onehunga. These are the principal sites of overflows in the central Auckland area.
The team is to report by late June, and that report will be considered by Council late July or early August.
SASOC strongly believes that it is important that the team’s conclusions:
♣ are made available for public consideration as soon as they are completed (SASOC has requested a meeting with HW for this purpose); and
♣ are peer reviewed by overseas experts (to ensure that a comprehensive plan is achieved for the entire city – but one which dovetails the Central Interceptor into existing wastewater/stormwater infrastructure in the central Auckland areas.
SASOC’s forward plan
There are many issues for Healthy Waters and Watercare to tackle in order to lift Auckland’s water quality through upgrading our drainage infrastructure. SASOC’s focus is on the elimination of polluted overflows into our harbours and watercourses.
This has led us to ask a series of questions of the CANOPy team, Healthy Waters and Watercare. These questions are too numerous to set out here, but will be sent to members if requested. They seek details of the existing infrastructure and a comparison of the costings for separation as against continuing with the combined system. Both would require reticulation of at least one new pipe on a street by street basis, although we also know that in some areas two pipes are already present. We have been asked by Healthy Waters to wait for the outcome of the CANOPy project for answers to many of our questions.
We are also planning to obtain epidemiological and scientific advice as to the dangers of overflow contaminants, as a necessary factor for Council to weigh when assessing the economics of the potential options. Although the formation of SASOC has been triggered by pollution from sewage we must keep in mind that there is also significant pollution in stormwater which contains heavy metals, hydrocarbon and other contaminants from roads (approx. 50% of total stormwater is generated by Council’s roads), roofs, manufacturing waste and so on.
It is also of significance that the Auditor-General is currently undertaking a review of local authorities’ funding of underground infrastructure. Once SASOC get answers to the questions put to Healthy Waters we may well wish to raise with the Auditor-General concerns that we have about the way that Auckland Council is funding its stormwater infrastructure.
Our current views on tackling the problems are:
• Separation of stormwater from sewage is undoubtedly best practice. If starting afresh no local authority would build a combined system.
• The preferred option is still separation of the combined pipe network (because the unknown contributing to most overflows is stormwater – the existing pipes are more than enough to carry sewage without overflows). The economics of this solution need to be examined carefully, taking into account how much has been done to date. Public health is an important element of any decision, as well as how we wish to be seen internationally.
• The fall-back position is removal of a large part of the stormwater from the combined network.
• Wastewater and stormwater must be appropriately treated before safe discharge to the environment.
• The Waterfront Interceptor should be completed contemporaneously with the Central Interceptor.
• Council should develop a comprehensive stormwater and wastewater plan for Auckland, going beyond the current “aspirational” plan to one with specific commitments and a finite period for implementation.
• The CANOPy report must be must be publicly notified by beginning July. The public should be given ample opportunity to make submissions on it, and the overflow issue generally, before CANOPY’s recommendations are accepted as the preferred course.
• Central government should set storm/wastewater discharge standards for urban as well as rural environments, and establish a regulatory body to monitor compliance.
We welcome feedback from members on any aspect of this report, or any other matter that warrants consideration.
With best wishes,
David Abbott Dirk Hudig
027 479 5764 021 0279 0800