AUCKLAND CITY COUNCIL – ISTHMUS DISTRICT PLAN REVIEW 2007/08 EUM/METROWATER TECHNICAL INPUTS

3. KEYWORDS: Water supply, reservoir, tank, drinking water, storage.

4. SUMMARY Water supply reservoirs are an essential element of the city’s water supply system, providing emergency storage and hydraulic buffering to aid in the continued delivery of drinking water to the city’s community. Historically reservoirs have been located on elevated sites, including a number of the city’s volcanic cones, to maximise supply pressures without the need for pumping. Some reservoirs on the volcanic cones are located above ground, while others are buried below ground with little surface expression. In the future, additional water storage will be required in response to growth if existing levels of water supply service are maintained at their current level. Options for this additional storage include extending the existing reservoirs, providing additional reservoirs in elevated locations within the city, and out of city/pressurised systems. Each method has its environmental benefits and drawbacks. In addition, the reservoirs are ageing and a number are approaching an age where significant rehabilitation/reconstruction will be required. This may include the replacement of the lid of below ground reservoirs or complete reconstruction of above and below ground sites. Currently some of the reservoirs are the subject of designations (typically Watercare storage sites on cones) while others are subject to existing use rights. While these authorisations generally allow operation and limited maintenance activities, they do not appear to provide for significant extension and potentially reconstruction. The functional requirement for water reservoirs will continue and the District Plan should seek to provide for the on-going operation, maintenance and potentially the reconstruction/extension of the reservoirs. Four methods of potentially providing for the reservoirs have been identified in the discussion.

1. PAPER TITLE: Water Supply Reservoirs

Lead Author(s): Stephen Grace; Asset Planning Team Leader, Metrowater Karen Bell, Ian Mayhew; Hill Young Cooper

2. PAPER ISSUE STATUS: Draft for Review

Issue No

Date Contributors Reviewer Summary of main changes

1 1.04.08 KB, IM S Grace Editorial changes

1 1.04.08 R Mills Editorial changes

Final 2.05.08 IM

5. RECOMMENDATIONS FOR CONSIDERATION FOR THE DISTRICT PLAN:

The District Plan options identified are: i. Designations – roll over and extend existing Watercare designations to cover maintenance, repair,

reconstruction, and potentially extension in some instances and designate Metrowater reservoirs similarly.

ii. General rules for reservoirs – make plan-wide rules that specifically apply to reservoirs that enable a range of activities to be undertaken;

iii. Provide specific zones for reservoirs, including relevant rules that permit certain activities associated with reservoirs;

iv. Continue to rely on existing use rights. On the basis of an initial assessment, options (i) and (iii) above appear to be the most appropriate ways of providing for these essential elements of water supply infrastructure for further consideration.

6. OUTSTANDING MATTERS:

# ITEM Comment on Work Pending to Address this

1 Review existing designations

None at this stage.

2 Consultation with Watercare and Metrowater

None at this stage. Discussions to date have focussed on functional need for reservoirs and likely future requirements and general options rather than preferred statutory approach and intentions re designation etc

Note: This is a summary page(s) for quick reference

7. SCOPE AND ISSUES

7.1 Issues Concrete water supply service reservoirs, owned and operated by Metrowater and Watercare Services Limited, are located at strategic locations around the isthmus. These tanks occupy elevated sites, due to the need to maximise supply pressures without the need for pumping. These tanks provide emergency storage and act as hydraulic balance tanks, buffering the water supply network from pressure changes due to pumping, or other operations. They are an essential part of the water supply network providing continuity of supply to Auckland’s residents. A number of these reservoirs are located on the city’s volcanic cones, with some being buried below ground with little or no surface expression, while others are visually prominent and can affect the appearance of the cones. The questions identified for consideration through the District Plan review include:

• Should the current reservoirs be provided for in the DP taking into account the benefits and adverse effects?

• Given Auckland’s population growth, will an increase in reservoir capacity be required?

• If so, will this involve construction of new reservoirs or expansion of existing ones and where are these to be provided and should they be designated?

• Are there alternative designs or methods that will mitigate adverse effects?

8. NARRATIVE:

8.1 Introduction/Background/Prior Work Infrastructure Watercare Services Limited operates some 27 reservoirs in the city (Watercare Services AMP 07 (Ref 1) , and pers comm. Watercare), located as follows:

1. Cornwall Park 2. Campbell Road 3. Domain 4. Khyber Pass (5) 5. Mt Albert 6. Mt Eden (2) 7. Mt Hobson (3) 8. Mt Roskill

9. Mt Wellington (2) 10. Onehunga FWT 11. Onehunga (3) 12. One Tree Hill 13. Ponsonby (3) 14. St Johns 15. Three Kings

As is indicated, there are multiple reservoirs located at some sites. These reservoirs may be components of a larger structure, or be multiple independent structures (eg Mt Hobson). Of these sites some 12 are located on volcanic cones. However, it is noted that most of the Watercare sites located on cones are buried underground, with the only surface expression being a flat area of ground and

some ancillary structures. While buried reservoirs reduce visual effects, it has implications for maintenance activities given the inability to easily access the reservoir structure. Metrowater operates the following five reservoirs: 1. Richardson Rd/Hillsborough Rd intersection 2. Hillsborough Rd 3. Waimarie St, St Heliers 4. Big King Reserve (off Duke St, Three Kings) 5. Mt Eden Reserve (Hillside Crescent) Of these, Sites 4 and 5 are located on volcanic cones. However, Metrowater has indicated that Site 5 may be currently surplus to requirements and consideration is being given to its future. Aerial photographs of the Metrowater reservoirs and the Watercare reservoirs on the cones are included in Appendix 1. Activities associated with the structures The structures themselves are “passive” in nature and generate little activity, although clearly structures on volcanic cones can have adverse visual and cultural impacts. There is no regular noise generated from these sites through the operation of mechanical plant. Occasionally repair or maintenance work may be undertaken to maintain the reservoirs (i.e. upgrade of ladders, platforms, concrete repairs, graffiti removal). Future upgrades may require more extensive construction works. Watercare Services has advised that the below ground reservoirs periodically require significant maintenance, particularly to the roof structures, to avoid seepage of untreated water into the reservoir. In a number of instances, Watercare has fenced off access to the grassed areas above the reservoir to minimise the risk of damage and informally indicated that they would like this to be in place for all underground reservoirs. Clearly extensive maintenance or rehabilitation of buried reservoirs will require significant works. Metrowater advises that as its reservoirs are above ground, it is believed that these 60 year old (on average) structures can be rehabilitated in the short to medium term using low impact techniques. However, both Watercare and Metrowater indicate that at some future date (10 to 20 years) the complete rebuild of some of these structures may be necessary, in which case the requirement to retain these structures would need to be reassessed. Both reconstructing and decommissioning these structures would involve significant works and would need to be controlled to preserve adjacent archaeological and geological features. Future Requirements Metrowater has a standard of 24 hours storage with Watercare written into the Bulk Water Supply Agreement. The volume of storage required to meet this standard increases over time as the population and the 24 hour consumption increase accordingly. What this means for the future is that there will be an increasing need to build reservoir storage if the current requirement is maintained (a bit like the drought standard it may vary over time) as it is considered that demand management measures such as rainwater tanks and water conservation will only minimally impact growing water demand.

The ideal sites for increased capacity will be at existing sites or new sites on elevated areas such as ridgelines. There are trends in overseas metropolitan areas to build elevated storage (i.e. water towers); however this is unlikely to be economic or acceptable in the Auckland environment. Another option is an increased reliance on pumped storage (i.e. larger pipes, or underground storage) that is pressurised to meet customer service levels. Whilst reliance on pumped storage is not a sustainable, environmentally friendly solution due to energy requirements and other factors; public opposition to unsightly water towers and increasing property values will drive at least a consideration of underground or “out-of-Auckland” storage solutions. There are no rules over what local storage should be provided and local network configuration plays a part in deciding the need for such storage (i.e. if a motorway compromises the security of storage provided by a Watercare reservoir then maybe a local solution is required). Metrowater is heavily reliant on Watercare to provide storage, however the nature and location of this storage is at Watercare's discretion. From Watercare's perspective they have a number of options to redevelop existing sites at Ponsonby, Khyber Pass, Mt Roskill, Three Kings and to make better use of other in-service reservoirs at Mt Wellington, Mt Hobson. They have plans to upgrade some isthmus reservoirs like Mt Eden (subject to obtaining the necessary consents), as well as new storage at Redoubt Rd in Manukau City (this is regional storage from Waikato/Ardmore WTPs). There is likely to be a trend towards the regional storage/integrated water management (which means that storage for Waitakere City comes from a reservoir in Auckland City). They will also obtain storage from a new 1300/1600mm diameter Hunua No.4 watermain from Redoubt Rd. However, it is important to note that storage outside of the area it serves offers a lesser level of security and should not be considered an automatic first choice. In respect of the existing water reservoirs maintenance activities are ongoing. These include low level maintenance such as grafitti removal through to more extensive renovations. The Metrowater water reservoirs are more than 60 years old and despite some undergoing refurbishment, they are all pre-earthquake design codes and pose an increasing risk as they get older. This is likely to also be the case for the Watercare reservoirs.

8.2 Status Quo Situation A number of the existing reservoirs owned by Watercare are currently designated in the Operative District Plan (See Appendix 1). The designations provide for these structures for Water Supply Purposes, but with the express proviso that activities or new structures not provided for under the notice of requirement are subject to a new designation or a variation that will be notified unless the adverse effects are minor. Metrowater’s reservoirs are not designated under the plan, but are subject to existing use rights. This has not caused any problem in respect of consenting requirements for minor maintenance activities, but may preclude significant redevelopment – except where this is consistent with the existing structure – although a range of ancillary consents will likely be required

8.3 Further Information/Details A recent review of storage options for the Auckland CBD put the cost of new storage between $23-55 million. Pumped options were not considered feasible and potential elevated storage sites were identified. None of the potential sites were volcanic cones, but were typically elevated ridgelines. While the location of sites on ridgelines is not without adverse effects, they are significantly less that those associated with the city’s volcanic cones.

8.4 District Plan Options There appear to be four main options for managing this issue through the reviewed Isthmus district plan as follows: Option 1. Designations There are several aspects to this option: A) Roll over any existing designations. As many of these existing designations are likely to be

very narrow in their content, this is probably of limited benefit and would only provide for minor maintenance works;

B) Introduce new designations for the existing sites, and potentially for those sites that are not designated, which provide for a wider range of maintenance/rehabilitation activities;

C) Introduce designations for new potential sites. Designation is useful for a number of reasons: 1. The zoning of the land may not be conducive to providing for reservoirs – e.g. a sensitive

open space zone or there are scheduled features such as the archaeological / geological features found on volcanic cones that have strong protection rules that make maintenance and access problematic. This is particularly pertinent for existing reservoirs, which have occupied such sites for more than 60 years and are an essential component of the water supply system.

2. If the reservoir is going to be the subject of some type of upgrade such as additional capacity, or the pipes and servicing infrastructure such as pumping equipment / transformers etc are likely to be upgraded in a known period then a designation can provide for this without the need for additional consents – if sufficient information is provided.

3. Notices of requirement received at the time of plan review tend to get a lower standard of review by the community because of the fact that they are part of a whole plan review so sensitive locations may not be the focus of submissions.

The option has some difficulties: 1. Where change is proposed, a reasonable amount of detail needs to be known about the type

of expansion / change that is anticipated to ensure that adverse effects are adequately characterised. However, this also enables the Council to consider the public work in a complete sense and draft conditions appropriate to the specific situation such as how long the designation is to be in place for (note there is a default period of 5 years under s 184(1) of the RMA) and to avoid overly restrictive designation conditions being imposed by Council out of caution.

2. It may not be possible to identify areas for new requirements as this level of detail has not been developed. Therefore, designating for anything other than existing sites, or likely extensions to existing sites, is not possible until more detail is known.

3. A notice of requirement means consultation must be undertaken with those whose land is directly affected by the designation, neighbours to the land, local iwi, and possibly other organisations such as the Department of Conservation, the New Zealand Historic Places Trust etc. The scale of this can change depending on the site, the issues arising and the likely effects of work that needs to be undertaken.

4. A notice of requirement requires a review of alternatives. While this may be a relatively straightforward exercise for existing sites (and designations), a greater level of detail will be required for new or extended designations.

5. There needs to be authority (and willingness) to designate. Authority is not an issue for Metrowater or Watercare who currently have requiring authority powers for the distribution of water for supply and for network utility operation of a sewerage system. However, it is

ultimately up to Metrowater and Watercare whether they wish to designate their reservoirs and the extent of activities that are covered within that designation.

Option 2: Make provision in general rules for reservoirs The current operative Isthmus District Plan has a section called Part 4A General Rules. Within this section is a specific set of issues, objectives and policies as well as rules, for Network Utility Services (4A.4). The plan recognises that maintaining an efficient infrastructure including access to services is important to the well-being of the people of the district and essential to the sustainability of the economic fabric of the City. Two examples of general rules for utility providers can be found in 4A.4 and in Proposed Plan Change 90 (PC 90) which is seeking to change the provisions in 4A.4. While neither of these examples provide adequately for reservoirs, they demonstrate the type of approach that could be followed in the reviewed plan. 1. Rule 4A.4.G.D provides for new reservoirs and changes to existing reservoirs as a

discretionary activity, under the activity “ Network utility services not otherwise provided for as permitted or controlled or restricted discretionary activities”

2. PC 90 includes a definition of Water Network: Water Network: Means a system comprising water links to permit the distribution or transmission of water. The definition is limited to the following: (a) Underground; pipes and fittings, meters, reservoirs, pumping stations, equipment,

cabinets. (b) Aboveground; aerial pipe bridges, pumping stations, reservoirs, fire hydrants, pipe

markers, equipment, cabinets.

Underground parts of the water network are provided for under PC 90 as permitted activities where they comply with the development controls, but it is likely that most above ground reservoirs would require discretionary activity consent under the framework of PC 90.

This option is useful for the following reasons:

• It recognises that there are a multitude of zones and sites where reservoirs (and the associated infrastructure) are found and provides for these activities wherever they occur.

• Through the ‘general rule’ provisions the plan anticipates that they should be able to locate across the city. Providing for them under the ‘general rules’ category ensures that the District Plan provides for their installation, operation, maintenance and upgrading, in a manner that enables the reasonable needs of the city to be met while achieving integrated management of their effects. This is consistent with the “whole of system” management of the water supply network.

The option has some difficulties: • A general rule needs to be written to be able to capture “reservoirs and associated

infrastructure” that is not site or asset specific. To write a rule that captures every reservoir and provide for it as a permitted/controlled activity could be difficult as reservoirs are located in a wide variety of locations such as on volcanic cones, in the middle of town centres (eg Khyber Pass and Ponsonby) as well as within road reserves. Each of these environments has their own specific issues.

• Broad permissive general rules may also result in unanticipated consequences such as the construction of new assets in undesirable locations.

Option 3: Make provision in the relevant zones for reservoirs as a specific listed activity. To achieve this option, a zone needs to be applied to each site (some reservoirs are in the road and they are currently unzoned). As part of the development of the zone and its application to a site, review of the zone’s objectives and policies and basic rules needs to be undertaken. As part of this it would be possible to develop rules for the specific reservoirs and their associated surrounds/ infrastructure and any proposed changes to them. A variation of this involves developing a specific zone package for the site. Included in this option is the identification of a low level activity status for the reservoir e.g. permitted / controlled which is possible if enough is known about the specific reservoir. This option is useful for the reason:

• That it allows for a tailored approach to be taken for each reservoir with the rules being developed to recognise the different locations e.g. different rules for a reservoir located on Ponsonby Road with a busy street frontage, to those for a reservoir in the middle of an open space area.

The option has some difficulties:

• Significant work needs to be done to identify the current and future use and development planned for the reservoir. The way that access to the reservoir is obtained, the management of the site etc need to be understood so that appropriate zone rules can be written.

Option 4: Rely on existing use rights. Section 10 of the RMA allows land to be used in a manner not provided for in a district plan where the use was lawfully established before the plan was notified or the use was established by a designation. This option is useful for the reason:

• The RMA allows changes in use to the extent that they are the same or similar in character, intensity and scale to what is currently occurring. This potentially allows for reconstruction or some minor reconfiguration consistent with the current situation, even in the situation where new structures may not be allowed at that location.

The option has some difficulties:

• The RMA requires that any effects of changes to the use are the same or similar and therefore significant changes in capacity may not be provided for under existing use rights.

• Existing use rights do not apply to an activity that has not been used for a continuous period of more than 12 months unless an application went to the Council within 2 years of it first being discontinued and the Council gave an extension.

• Existing use rights do not apply if reconstruction or alteration of or extension to a building increased the degree to which the building fails to comply with the plan. This would clearly be an issue for reservoirs on a cone where the rules related to heritage items and other aspects are very strict.

• Consents may also be required for ancillary activities (ie earthworks) consistent with the rules in the plan. These may be significant and potentially difficult to obtain in some circumstances.

8.5 Discussion Understanding the life of these vital assets is critical to deciding how to provide for them in the district plan. Leaving these sites to rely on existing use rights for the life of the next plan, which could be out to 2025 (assuming the plan is notified in 2010 and takes 5 years to be made operative), is possibly unsustainable given the requirement for increased storage capacity to provide for growth and the need

to reconstruct a number of these assets within this timeframe. While it is noted that other storage options exist, such as remote storage or pressurised systems, these are not without undesirable consequences including a lower level of security of supply and increased energy requirements. Designation of the sites is likely to be a robust option to provide for the ongoing use and additional development. However, a designation for each site would need to have a life of 15 plus years and a reasonably high level of information would be required to identify any likely changes in that period so that a robust notice of requirement and conditions could be developed to be flexible enough to accommodate the medium to long term requirements. Clearly discussions would need to be held with Metrowater and Watercare in this regard, as the responsibility for preparing the notices of requirement would fall on them. In respect of designating new assets, this cannot be done generically in advance of a specific need for a new storage reservoir, its detailed design, and a comprehensive assessment of adverse effects. So while new water storage reservoirs may be required in the future to provide for growth and a designation is an appropriate way of providing for them, this would need to be undertaken by the relevant requiring authority at that time. A similar level of information and assessment would be required to provide each site with site specific zone provisions (i.e. Option 3). Essentially rules would need to be written for each zone in the context of the relevant issues. This has some advantages in that it would not be necessary to have detailed design work, a specific period in which the works are to be delivered and that the majority of activities could be provided for as permitted activities subject to compliance with general provisions. However, some basic parameters such as maximum height, coverage etc would be required. Option 2, the provision of general rules, is the easiest option to cater for. However, again, this option requires each possible scenario to be identified and captured at a general level so that the rules can be written to accommodate them. It may be difficult for general rules to accommodate such a wide range of scenarios and as identified above, may lead to unanticipated consequences.

8.6 Outstanding Matters/Additional Research The Notices of Requirement supporting the Watercare designations have not been reviewed. Therefore the extent of the activities that are provided for by the existing designations is unknown, although it is anticipated that they do not provide for activities other than routine maintenance. Examples of the notices of requirement should be sourced and reviewed in this regard. Discussions should be held with Metrowater and Watercare regarding their likely preference, as they will be required to lodge any notices of requirement. In this regard it is noted that designation is available to both requiring authorities irrespective of the approach taken in the District Plan.

8.7 Interim Conclusions [District Plan Implications] Water reservoirs are an essential component of the water supply network. Storage requirements will increase proportionally to growth, although there are a number of ways to provide storage – each with their own benefits and drawbacks. It is considered appropriate for the District Plan to include provisions that enable existing reservoirs to be operated and maintained, and potentially extended to provide additional capacity to meet growth and maintenance/replacement requirements. Several methods of providing for reservoirs in the Plan have been identified. The preferred method is to rollover existing designations, possibly enabling a greater level of maintenance/reconstruction, and potentially to designate other essential reservoirs similarly. Clearly, such an approach would need to be undertaken in conjunction with Metrowater and Watercare, who are the requiring authorities in respect of this issue. Note that the “roll over” of designations does not apply to the Metrowater reservoirs, which are not currently designated. However, other methods also exist including general rules to enable the operation and maintenance of reservoirs or site specific zones and associated rules.

9. OVERALL COMMENTARY Not required.

10. REFERENCES (ANNOTATED)

No Author Title Date COMMENT1

1 Watercare Services Ltd

Watercare Asset Management Plan

2007 Online version

APPENDIX 1 Maps of Metrowater reservoirs and maps and designations for Watercare reservoirs located on volcanic cones

Site 3 Waimarie St Site 4 Big King Reserve Three Kings (Watercare reservoir also located at reserve)

Site 1 Hillsborough Rd/Richardson Rd Site 2 Hillsborough

Site 5 Mt Eden Reserve (Watercare reservoir also located here)

Metrowater reservoirs

Watercare Reservoirs Mt Albert

Mt Eden (2)

Mt Hobson (3)

Mt Roskill

Mt Wellington

One Tree Hill (2)

Three Kings

Domain