Why is the Council doing this work?
All councils in New Zealand are required to identify and manage areas that are at risk from natural hazards. Keeping our communities safe and protecting our environment is part of our job, so it’s important we do this work.
The Council has recently obtained improved information for natural hazards affecting the district, including flooding, fault line location, coastal erosion and liquefaction areas. The Council is reviewing its District Plan and the new information will inform the revised natural hazards provisions.
How do I find out if my property is affected?
Use our interactive map how your property may be affected by the updated natural hazards information.
What if I am in a high flood hazard area?
Existing use rights will be able to apply to existing activities. Should you wish to do a large extension to your existing building or build a new building, it is likely that you will need assessment prior to undertaking the works to determine if mechanisms are available to avoid or reduce the effects of flooding.
What does 0.2% and 0.5% Annual Exceedance Probabilities (AEP) mean and how/why have these levels of risk been used?
A 0.5% AEP is another way of saying a one in 200 chance of a flood occurring in any one year. 0.2% similarly means a one in 500 chance that a flood of this type could occur in any one year.
The AEP levels come from the Canterbury Regional Policy Statement. The Council is required to give effect to the Regional Policy Statement (to be included in the District Plan review) and therefore has to use these events in its assessment of risk.
Aren’t the Council’s flood protection works supposed to protect us from flooding?
The Council provides some flood protection works that are designed to provide protection to property and infrastructure from moderate to heavy rainfall events, but are not designed to cope with extreme flood events. The rainfall that flood protection and drainage works are designed to cope with is at a level that could be expected once every 10 years to once every 50 years.
The District Plan can cover protection to human life and to houses in more extreme rainfall events that result in flooding. In events of this nature it is expected that existing drainage systems including streams and rivers would be overwhelmed and some damage would be caused to infrastructure and property.
What is displacement and diversion of floodwater and why does it matter?
Development of a site, for example through earthworks or placement of structures, can in some cases affect the flow of floodwater, or how deep the water is.
As an example, a new building may be placed so that it redirects the flow of floodwater onto roads or neighbouring properties where they can adversely affect traffic, drainage and the damage or risk from floodwater for other people and property. Moving the path of floodwater is diversion.
Displacement relates to the level of floodwater, if earthworks raise the level of one site, it may mean that other adjacent sites take more of the floodwater as a consequence. In an area, displacement can occur if the intensity of building development increases, leaving less area for floodwater to pond, which can result in higher water levels.
What is ‘freeboard’?
Freeboard is the term given for an allowance in floor levels above the modelled flood level, which allows for modelling inaccuracies, construction tolerances, network failures and natural environmental factors such as wave and wind effects. All local authorities have a freeboard level; this tends to vary from 300 millimetres to 500 millimetres.
How has climate change been factored into the hazards maps?
We know climate change will lead to a rise in sea level over time, as well as other changes such as increased rainfall intensity during storm events.
These will affect flooding in coastal areas and further inland. Climate change scenarios have been used to inform the flooding and coastal erosion modelling.
Will this stop me putting any more buildings on my land?
The Council has not yet confirmed how the District Plan will respond to the new information.
There will likely be some instances when a resource consent will be required, particularly within high flood hazard areas or within fault avoidance areas.
What does this mean if I want to renovate or extend my house?
If you are located on or near a fault line, you may need specialist geotechnical advice for any new building foundation for significant house extensions.
If you are located in an area subject to flooding you may need specialist flooding advice for any new building or significant house extensions.
This has generally been the case for some time in many areas of the district. However, It's likely that small extensions to houses will be permitted under the district plan.
Will this stop me subdividing my land?
You will still be able to apply to subdivide your land. The natural hazard risk associated with the land will be taken into account during the assessment of any application for subdivision. You would still need to comply with minimum lot size as set out in the District Plan and any other existing requirements.
What do these proposed changes mean for my current building and/or resource consent application?
Any current or new building/resource consents aren’t affected by the proposed rules for managing flood risks until the new District Plan is fully in place. Until then current rules for building and resource consents continue to apply.
However, for any property that has been assessed as potentially being at risk from natural hazards, a new Land Information Memoranda (LIM) report will now contain a note that indicates that the property may be susceptible to natural hazards.
The note will also identify the latest technical information held by the Council. This is a legal requirement. Councils have to include in a LIM all relevant information they hold about a property in relation to natural hazards.
I don’t agree with your mapped area on my property being at risk from flooding as it has never been flooded before. What should I do?
The mapped areas are not a record of where land has flooded in the past. They are a result of an assessment where land may flood during a large or extreme flood event in the future.
We’re expecting to notify the Proposed District Plan for formal public consultation in early to mid-2021. Then you will have the opportunity to make a submission on any of the proposed provisions, including how the flood areas are mapped.
Any submission during the formal public consultation seeking to change a mapped area will need to be supported by sufficient evidence for such a change to be accepted.
Doesn’t the Building Act already require minimum floor levels?
The Building Act, Building Code and the District Plan (or a resource consent condition) may require minimum floor height levels for buildings.
The Building Code requires minimum floor levels to provide protection from an event having a 2% probability of occurring annually, usually defined as a 1 in 50 year flood event. Where inundation is considered a natural hazard (the threshold for a natural hazard has been determined by Court decision to be a 1 in 100 year event in relation to flooding), building work must not accelerate or worsen the hazard on the property on which the building work is being carried out or any other property. Where building consent is granted in an area that is considered a natural hazard under the Building Act Council must identify and register the hazard with the Registrar-General of Land.
If the floor level requirement in the District Plan is less than that of the Building Act, the Building Act requirements will still need to be met. If the District Plan has a higher requirement, then that will need to be provided even if it is higher than that required by the Building Act. This is because the District Plan can impose a greater level of protection in areas where higher flood levels could be expected.
More information can be found here: https://www.waimakariri.govt.nz/__data/assets/pdf_file/0021/34464/Fact-Sheet-Building-Location-Certificate-April-2020.pdf
If a resource consent is required what information will be needed to get one?
You will need to provide detailed plans of your proposed building including a site plan, and provide an assessment of effects appropriate to the level of risk associated with your property.
For example this may involve getting a flood hazard or geo-technical expert involved. There will also be a consent application fee.
Will information about flood hazards be included on my LIM?
Yes, and this has previously been the case. A Land Information Memorandum (LIM) is issued by the Council and contains important Council information relating to a property. It is an important part of the due diligence process that helps people make a decision about whether to purchase a property or not.
The property zoning and its location within any areas that have special requirements, such as a Hazard Area, will be noted on the LIM to ensure that the owner, or prospective owner, is aware of the location of the property in regard to hazard risk and that there may be special requirements or restrictions that apply to the use and development of the site.
What is a fault awareness area and what does it mean?
The fault awareness area is located on either side of an identified active fault line, and is mapped to ensure that land owners and service providers are aware of the presence of a fault line before they decide to build.
Awareness areas are larger than avoidance areas as the exact location of the fault is not usually clear at the land surface. Within the awareness area special consideration should be given to geotechnical investigation and the design of building platforms.
Why is the liquefaction area mapped?
The liquefaction area is mapped to ensure that owners are aware of the risk from liquefaction and lateral spread prior to building to allow for evaluation and design in these locations. This has been included on LIMs for some time. This is consistent with the Canterbury Regional Policy Statement, which sets high level policy direction that Waimakariri District Council must give effect to.
What effect will the identified hazards have on my property values?
There are many factors which affect property values. The risks posed by natural hazards are one of them. A registered property valuer may be able to advise on any enquiries regarding property value. However, it must be noted that the natural hazards mapped by the Council are not new, rather in most instances the mapping expands on information already held by the Council and already provided on LIMS.
What effect will this have on my insurance?
The natural hazards mapped by the Council are not new – the insurance industry already knows they may potentially affect Waimakariri District properties.
The Council cannot provide guidance or indications of potential consequences for insurance resulting from the updated natural hazards information. If you would like to know more about this, you should contact your insurance provider for further information about any insurance implications.
Why has the Council previously allowed development to happen in new residential areas that are at risk to flooding or liquefaction?
Since the previous rules were developed the Council has received updated hazard and flood modelling information which increases the understanding of risks posed by natural hazards.
The information that is available about natural hazards wasn’t available to the extent that it is now. Now that this information is available, the Council has a responsibility to manage and minimise risks to protect people and property. The District Plan needs to be updated to respond to this new information and plan for management of risk situations.
What is the Canterbury Regional Policy Statement?
The Canterbury Regional Policy Statement (CRPS) sets the strategic policy direction for resource management in Canterbury, and has been developed by Environment Canterbury (ECan). The district plans of the Councils within Canterbury must give effect to the direction set by the CRPS.
The CRPS can be viewed on Environment Canterbury’s website.