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Part 3: Setting well-informed levels of service

Managing stormwater systems to reduce the risk of flooding

3.1
In this Part, we discuss the need for the three councils to provide better information:

3.2
We focused on the 2018-28 long-term plan process to make our assessment because this was the most recent asset management process that involved the three councils deciding levels of service and providing information about them to the community. However, this is not the only time that conversations about the management of their stormwater system occur between councillors and the community.

Better information needs to be provided to councillors when setting the levels of service

3.3
Weaknesses in the three councils' information about their flood risk and the current state of their stormwater systems mean councillors have not had all the information they need to make well-informed and deliberate decisions about their stormwater systems.

3.4
As part of councils' asset management processes, councils should make decisions about what type of event the stormwater system is expected to withstand. This decision is also known as levels of service.

3.5
We expected councillors to receive relevant and reliable information about their stormwater systems and flood risks to make well-informed and deliberate choices about the levels of service they are going to provide their community with, now and in the future. This includes making trade-offs, mainly in terms of what level of service the community is willing to pay for.

3.6
Councillors need information in a form they can understand. This will depend on the nature of the decision and the requirements of councillors.

3.7
As part of the long-term plan process, councillors from the three councils received information about the cost and funding of stormwater systems, significant issues, and priorities. This information was presented in workshops, reports, and other documents related to the long-term plan.

3.8
Councillors also received information about specific issues. For example, staff and consultants presented proposals to reduce flooding in South Dunedin to Dunedin City councillors.

3.9
We sought feedback from councillors and community board members on whether they were given enough information to make informed decisions about stormwater systems during the 2018-28 long-term plan process.

3.10
To get this feedback, we surveyed councillors at Porirua City Council, and councillors and community board members from Thames-Coromandel District Council. We received a total of 14 responses. We also received feedback from a councillor at Dunedin City Council.

3.11
Generally, Porirua City and Dunedin City councillors thought:

  • they got enough information to make the necessary decisions;
  • the information was focused on the right issues and at the right level; and
  • the information was presented in a useful way.

3.12
However, Thames-Coromandel District councillors and community board members had more mixed views.

3.13
Respondents also identified some matters for improvement. These included:

  • information about, and consideration of, different levels of service options, including cost, benefit, and risk;
  • performance information about the stormwater system; and
  • planning to improve the protection for areas prone to flooding.

3.14
We expect councillors to receive better information. In particular, we consider that, to make informed decisions about stormwater systems, councillors need information about:

  • current and future flood risks and options for managing them – for example, land-use controls or flood-mitigation infrastructure;
  • the current levels of service for the stormwater system and how they might be achieved – for example, the stormwater piped network might be designed to handle a one-in-10-year event, while overland flow paths might be designed to handle a one-in-50-year event;
  • the current performance of the stormwater system – for example, whether the system is performing to its design standards; and
  • the implications – for example, the risk from events that exceed the design standards of the stormwater system, the effect on insurance premiums for home and business owners, or other benefits such as improved urban amenity and water quality.

3.15
We also found that there was a lack of clarity about the process used to set the levels of service.

3.16
The three councils already have some of the information available. For example, under the Regional Standard for Water Services, Porirua City Council's overall stormwater system should be able to handle up to a one-in-100-year event. This is to be achieved by the:

  • initial protection (called primary protection) through the stormwater piped network, formed drainage channels, and soakage systems being designed to handle up to a one-in-10-year event;
  • primary protection being designed to handle up to a one-in-100-year event where secondary flow paths are not available; and
  • secondary flow paths being designed to handle up to a one-in-100-year event.

3.17
However, there are weaknesses in the three councils' information about their flood risk (see paragraphs 2.2-2.20) and about the current state of their stormwater system (see paragraphs 4.2-4.29).

3.18
In our view, this means that, to date, the three councils have not had all the information they need to make well-informed and deliberate decisions about managing their stormwater systems. As Local Government New Zealand states in a 2015 position paper:

… applying asset management disciplines require detailed and well-understood information on the state of the physical assets and the level of likely demand in the future.9
Recommendation 2
We recommend that councils provide elected members with the necessary information and options, including about local flood risks and their stormwater systems, to make well-informed and deliberate decisions about investment in their stormwater systems.

The community cannot provide informed feedback

3.19
As part of the long-term plan process, the three councils compiled relevant information about the cost, funding, and significant issues for the management of stormwater, which is available to their communities. However, these communities had limited information to help them understand the remaining level of flood risk and decide whether it is acceptable.

3.20
A long-term plan sets out what a council intends to deliver to its community and how the council intends to pay for it. Consulting with communities on the long-term plan is a crucial step in making sure that this plan is the right one for the community.

3.21
Councils need to provide their communities with information that is relevant, reliable, and accessible, so they can have the "right debate" to plan for the future. This also includes providing the information their community needs to understand the trade-offs associated with providing the desired levels of service, if they wish to.

3.22
Even if councils were not specifically consulting on levels of service, they are expected to make relevant information available on the levels of service for their stormwater systems and the implications of that as part of the information supporting the consultation document and the final long-term plan.

3.23
Making this information available would help people provide well-informed feedback to their council, if they choose to do so, and allow them to hold the council to account for the performance of the stormwater system.

3.24
The three councils made available relevant information about the cost, funding, and significant issues for the management of stormwater through the long-term plan (such as in the 30-year infrastructure strategies). For example, Thames-Coromandel District Council highlighted the significant issues for stormwater as being:

  • the age and condition of its stormwater pipe network in Thames and Coromandel township, and parts of the network in Whitianga; and
  • the effect of increasing national and regional standards for the discharge of stormwater into the sea or freshwater bodies such as rivers.

3.25
Thames-Coromandel District Council also highlighted climate change, coastal hazards, and resilience as significant issues for all of its activities.

3.26
However, the three councils could have made more information available to their communities to help them understand the remaining level of flood risk and decide whether that level of risk is acceptable. Information that could help the community understand the remaining level of risk, but is not currently available, includes:

  • the current levels of service for the stormwater system (such as the event size the system is designed to handle) and how they will be achieved;
  • the current performance of the stormwater system; and
  • the implications in terms of remaining risk and cost.

3.27
If councillors and the community do not fully understand what the stormwater system is designed to achieve and the remaining level of flood risk, they cannot make informed decisions about how to invest in stormwater systems and prioritise their limited resources effectively.

Recommendation 3
We recommend that councils improve the information they make available to their communities so that people can understand:
  • the potential risk of flooding;
  • what the council is doing to manage that risk, including how it is managing the stormwater system and at what cost; and
  • what the remaining risk is to the community.

Councils provide relevant information to their community during significant flooding events

3.28
Councils have a role in responding to large floods by co-ordinating with emergency services, relevant commercial businesses such as electricity providers, and other agencies to minimise the effect of flooding. This includes providing information to the community to help them minimise health and safety risks and property damage during a flood.

3.29
The three councils have provided relevant information to the community during and after significant events. For example, on 1 February 2018, Dunedin City Council informed the community that it should start preparing for possible flooding. During the next two days, the Council provided several updates on the actions it was taking to reduce the risk of flooding and on the declaration of a state of emergency. After the emergency had ended, the Council provided a further update on actions to help people and businesses to recover from the flood.

Questions to consider
For councils:
Have you, with your community, defined what the acceptable level of risk is and the level of protection that your stormwater system needs to provide?
For people to ask their councillor:
How much protection from flooding is the stormwater system going to give me?
What actions can I take to reduce the amount of stormwater run-off from my property?

9: Local Government New Zealand (2015), Improving New Zealand's water, wastewater and stormwater sector, Wellington, page 13.

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CoverManaging stormwater systems to reduce the risk of flooding

ISBN 978-0-478-44299-1