Flood hazards

Adoption and operative date

Decision

On 11 December 2018 Taupo District Council adopted the Commissioners' recommended decision for Plan Change 34 - Flood Hazard (dated 26 November 2018), and the Section 32AA report (dated 23 October 2018).

The Commissioners recommendations, Planner's Section 32AA Report, and public notice (dated 21 December 2018) can be viewed here:

Plan Change 34 recommendations of Hearing Commissioners (PDF, 1MB)

Section 32AA Report (PDF, 345KB)

Notification of decisions on submissions to plan change 34 (PDF, 153KB)

The decision version of the flood hazard areas on the District Plan maps can be found on our District Plan website.

Under Clause 14 of the First Schedule to the Resource Management Act 1991 any person who has made a submission on Plan Change 34 may appeal Council's decision on their submission to the Environment Court.

Appeals must be in the prescribed form and lodged with the Environment Court within 30 working days of serving the notification of the decision.

More information on the appeals process is available on the Ministry for the Environment website

Hearings

Hearing of submissions took place in the Council Chamber in October 2018.

The hearings panel is:

• Dr Jeff Jones (chair)
• Mr Steven Wilson
• Councillor Rosanne Jollands

The hearings chair has issued a minute on the hearing which can be accessed here:

Minute from Chair.pdf

The section 42A report by the planning officer and Dr McConchie's evidence can be found below:

• Section 42A report.pdf
• Section 42A report Appendix B.pdf
• Addendum for Section 42A Report.pdf
• Statement of evidence of Dr Jack McConchie.pdf

Additional supporting documents:

• Summary of Ngati Kurauia submission October 2018.pdf
• Transpower Taupo DC PC34 Hearing Statement Lodged 20181004.pdf
• WRC Letter to Plan Change 34 Hearing Panel October 2018.pdf
• P B Steel for Friends of Lake Taupo - Hearing Submission.pdf

Evidence:

• Hydrology evidence D Payne Mercury.pdf
• Planning evidence N Foran Trustpower.pdf
• Planning evidence R Hansen Mercury.pdf

Copies of submissions received are available on request to info@taupo.govt.nz.

Background

Plan Change 34 Flood Hazard updates and identifies new flood hazard areas, and defended areas, in the Taupo District Plan and introduces new objectives, policies and rules to manage development and activities within identified flood hazard areas.

District Plan Change 34 Flood Hazard.pdf

Section 32 report.pdf

Why do we need to change this part of the District Plan?

The Resource Management Act requires the Council to have a plan explaining how land is managed. This is called the District Plan. Plan Change 34 helps Council meet its responsibilities to identify flood hazards and manage development to mitigate risks to people and property. Those responsibilities stem from the Waikato Regional Policy Statement and the Resource Management Act 1991.

The current flood hazard information in the District Plan:

• does not identify all of the known flood hazard areas associated with rivers and Lake Taupō
• identifies some areas as subject to flood hazard that the new modelling information shows are no longer expected to be affected by future flood events
• doesn't consider the future effects of climate change and tectonic subsidence
• does not use a risk based approach to managing flood hazards which is required through the Waikato Regional Policy Statement.
• does not provide sufficient control over development in high flood hazard areas, in accordance with the requirements in the Waikato Regional Policy Statement.
• imposes unnecessary regulatory costs on those with a low level of flood hazard.

These issues are addressed by Plan Change 34 in the following ways:

• Areas affected by the flood hazard are defined spatially and in relation to the depth of likely inundation. This knowledge helps people to make better decisions about how to manage the associated risks.
• Introducing flood hazard information into the District Plan, that includes the likely effects of climate change and tectonic subsidence, provides people making decisions with enhanced knowledge. These effects may not be experienced in the short term, however the planning related decisions to create new allotments or establish built structures will extend well into the future.
• The Plan Change shifts the direction of the District Plan away from a generic assessment of hazards to a risk based approach. This creates a more enabling regulatory environment for activities in low hazard areas, while providing more for a more considered decision making in high hazard areas.

Plan Change 34 updates the existing flood hazard areas around Tokaanu Stream and the Tongariro and Tauranga Taup Rivers, as well as identifying new areas potentially at risk from flooding, particularly around the shore of Lake Taup and on the Hinemaiaia River, the Kuratau River and the Whareroa Stream. It also identifies defended areas which are areas that are protected from flooding by a flood protection scheme (e.g. stop bank). The plan change introduces new objectives, policies and rules for these areas of flood hazard and identifies defended areas

Background information

Planning for natural hazards is one of our core responsibilities under the Resource Management Act 1991 (RMA). Given we have a lot of waterways throughout the district, there is a high probability of future flooding.

We commissioned Opus International Consultants Limited to update our flood hazard information. They used computer modelling of flooding in a 1% Annual Exceedance Probability (AEP) event, otherwise known as a 1-in-100 year flood. The areas prone to flooding have been classified as low (yellow), medium (orange) and high (red) risk.

We did this because we are required under the RMA to have a plan for the district explaining how land is managed. Section 31 of the RMA specifically requires Council to "control any actual or potential effects of the use, development or protection of land, including for the purpose of avoidance or mitigation of natural hazards". The flood hazard information will eventually be included in the District Plan.

Flood hazard classifications

The flood hazard reports show the likely risk of flooding relating to the depth of water and its velocity - how fast the water is moving. There are low, medium and high classifications for a 1% AEP flood hazard. These classifications reflect their likely impact on people and property. The risks have been mapped using the Waikato Regional Council Flood Hazard Classification.

High hazard (red)

The Waikato Regional Policy statement defines a high hazard as: land that is subject to river or surface flooding during an event with an annual exceedance probability of no more than one per cent, and during such an event:

• the depth of flood waters exceeds one metre;
• the speed of flood waters exceeds two metres/second; or
• the flood depth multiplied by the flood speed equals or exceeds 1.

Medium hazard (orange)

A medium hazard is defined as:

• the speed of flood waters is greater than one metre/second but equal to or less than two metres/second ; or
• the flood depth multiplied by the flood speed is equal to or greater than 0.5 and less than 1.

Low hazard (yellow)

A low hazard is defined as:

• the depth of flood waters is one metre or less;
• the speed of flood waters is one metre/second or less; or
• the flood depth multiplied by the flood speed is less than 0.5.

Defended areas

As well as identifying flood hazard areas, we have also identified defended areas. Defended areas are protected by a flood protection scheme (e.g. stop bank). You can see these defended areas on our e-District Plan.

The Waikato Regional Policy Statement directs us to identify these defended areas in the District Plan. This is to ensure that landowners are aware that there is an element of risk that the stop bank may fail. These areas will be included in the District Plan but we are not proposing to have any specific rules attached to them.

Previous consultation

We have conducted two rounds of consultation with affected property owners and other parties such as infrastructure providers. Through this process we were able to test the draft flood hazard maps, (which shows the location of flood hazard areas in a 1% AEP), and the draft objectives, policies and rules that may apply to flood hazard areas. We received some useful feedback which has enabled us to amend the draft plan change maps and provisions. As a result the draft flood hazard maps and draft objectives, policies and rules were amended. The broad principles underlying these rules are to:

• Discourage development in high risk flood areas;
• Control the design of development in low and medium risk flood areas;
• Recognise existing investment in flood areas;
• Plan for vulnerable people and infrastructure within flood areas; and
• Provide for infrastructure that is not vulnerable to flooding.

Plan Change 34 Flood Hazard was publically notified on 20 October 2017. As part of this notification we wrote to all the affected landowners and stakeholders notifying them of the plan change.

Insurance and valuation information

We have commissioned a report on property valuations and sought advice from the Insurance Council of New Zealand. Each insurance and valuation company has its own approach to managing flood risks, so you are best to talk to your insurer or valuer directly about how flood risk could affect your property. Those reports are available here:

• Insurance Council of New Zealand report
• Truss and Keys valuation report

Frequently asked questions

Our Frequently Asked Questions and Process map can be found here:

Flood hazard FAQ and process revised May 2017.pdf

Contact us

If you have any questions, feel free to contact our team on 0800 ASK TDC or e-mail floodhazard@taupo.govt.nz

Flood hazard reports

The flood hazard reports from Opus International Consultants Ltd can be found here:

Document Links

• Hinemaiaia-River-Flood-Assessment-Report (PDF, 3.5MB)
• Kuratau-River-Flood-Assessment-Report (PDF, 3.3MB)
• Lake-Taupo-Foreshore-Flood-Assessment-Report (PDF, 4.6MB)
• Tauranga-Taupo-River-Flood-Assessment-Report (PDF, 6.1MB)
• Tokaanu-Stream-Flood-Assessment-Report (PDF, 12.3MB)
• Tongariro-River-Flood-Assessment-Report (PDF, 4.2MB)
• Whareroa-Stream-Flood-Assessment-Report (PDF, 3.2MB)

An independent peer review of the seven reports was undertaken by NIWA who confirmed the methodology was appropriate.

• An updated peer review report by NIWA
• A peer review discussion document by Opus and signed off by NIWA
• This technical compendium by Opus technical compendium goes into more detail around the methodology used.