• A new study has been completed for 13 catchments in the Teviot Valley looking at debris flood hazard and risks. The new mapping identifies areas more likely to be affected by debris floods and the possible effects on people, places and key infrastructure. 
• Regional alluvial fan hazard information for the Teviot Valley has been published by Otago Regional Council) since 2009, including on Alluvial Fans | ORC AGOL Natural Hazards Portal 
• The new detailed mapping for 13 alluvial fans is complementary to and refines the regional data. 

• Areas of higher hazard and significant risk are identified in all 13 creeks.  Risk is generally higher closer to the creek channel but each fan is unique. 
• Communities and residents are encouraged to get familiar with the new maps and findings, and share knowledge with neighbours. 
• Detailed risk and hazard mapping is available above for the 13 catchments

• The study methodology for natural hazard risk assessment is consistent with ORC partially operative Otago Regional Policy Statement (APP6 in pORPS).   
• APP6 specifies a 4-step process, including an initial Qualitative Risk Assessment as a screening tool. For higher risk areas, the last step is a Quantitative Risk Assessment where risk levels are calculated spatially and output is maps of Annual Individual Fatality Risk (AIFR) and Annual Property Risk (APR). This type of detailed approach is consistent with best practice such as GNS Landslide Planning Guidance 2024. 

• The potential impacts of climate change are included, as required by partially operative Otago Regional Policy Statement (pORPS). 
• Risk maps are shown for two scenarios, Present Day and RCP8.5 (high climate emissions track). 
• A trigger for debris floods is intense rainfall in one hour.  Triggering rainfall may occur more often under climate change scenarios. 

• This new information helps councils and infrastructure providers make good long-term planning decisions. It complements regional alluvial fan information that has been available since 2009 (Alluvial Fans | ORC AGOL Natural Hazards Portal) 
• Hazard and risk information could be used by decision makers when considering: emergency planning, natural hazards management, land-use planning, infrastructure planning and construction; and building consents. 
• If you are planning to build, extend or develop your property, Central Otago District Council can advise what this means for you. 

• The new study does not require anyone to move or relocate.  
• Communities and residents are encouraged to get familiar with the new maps and findings, and share knowledge with neighbours. 
• If you are in a hazard area, consider preparing your household and your work by having an emergency plan Get prepared — Get Ready (NZ Civil Defence) — Emergency preparedness in New Zealand 

• If you are in a hazard area, consider preparing your household and having an emergency plan Make a household plan — Get Ready (NZ Civil Defence) — Emergency preparedness in New Zealand 
• Check information from your local community response group. 
• Sign up for CDEM alerts (https://www.otagocdem.govt.nz/useful-stuff#emergency-mobile-alert-ema) 

• NZTA upgraded several culverts following debris floods in November 2017 to enhance capacity and resilience.
• However WSP notes that culverts along SH8 have historically impeded debris flood flows, causing inundation upstream and laterally from the culvert location in the channels.
• As part of the new study, WSP carried out a Qualitative Risk Assessment that includes an assessment of the potential impact on lifelines, consistent with ORC methodology (pORPS APP6). Inundation of sections of SH8 is identified for all catchments. Shallow debris flood inundation is likely to be cleared quickly (<1 day). Deeper and more extensive inundation is associated with greater damage and longer service outage.  Table 49, Table 50 and Table 51 describe the impact on lifelines for the three scenarios.

• Yes, new natural hazard information with go on LIMs 
• Local Government (Natural Hazard Information in Land Information Memoranda) Regulations 2025 sets the requirements for providing natural hazard information in LIMs. 

• Regional alluvial fan hazard information for the Teviot Valley has been published by Otago Regional Council) since 2009, including on Alluvial Fans | ORC AGOL Natural Hazards Portal 
• The new detailed mapping for 13 alluvial fans is complementary to and refines the regional data. The new information is consistent with the regional data. 
• Insurance companies often use a range of information when they assess risk, and hazard reports are only one part of that picture. 
• The new study does not automatically change your insurance. We cannot say how individual insurance policies may be affected, as decisions are made by insurers on a case-by-case basis. If you have concerns, you may choose to discuss your cover with your insurer or a broker. 

There are a range of different options available to help manage debris flood impacts: 

• Physical structures like barriers, channels to redirect flows, and stronger and larger capacity culverts can help control water and debris during heavy rain. These options can be expensive to construct, will often require sufficient space to be effective, and require detailed design work and regular maintenance to ensure they remain effective over a long period of time.  
• Non-structural measures such as early warning systems, community education, and regular clearing of the existing stream channels and culverts can be practical and cost-effective ways to help reduce the impacts of debris floods, especially for a small, well-connected community like Roxburgh. 
• Planning tools like zoning rules and preserving natural buffer areas around the creeks can provide long-term protection by avoiding intensive development within areas that are most likely to be affected by debris floods. These require robust council policies and community support to implement. 
• Long-term adaptation and resilience such as preparing communities and households, allocating resources to strengthen resilience, embedding local knowledge and mana whenua values in planning, and promoting collaboration among agencies and communities. 

• You can also contact our Natural Hazards team on 0800 474 082 or email us at customerservices@orc.govt.nz 
• If you or your group has specific concerns we can get together for a chat. 
• ORC webpage for self-study Debris flood hazard in Roxburgh 
• ORC Natural Hazards Database hazard mapping (search by address or place) Alluvial Fans | ORC AGOL Natural Hazards Portal 

• No decisions have been made yet regarding follow-up work. 
• Your feedback, concerns and suggestions will be an important part of the process. 
• ORC will continue to work closely with Central Otago District Council (CODC), Civil Defence Emergency Management Otago (CDEM), New Zealand Transport Agency (NZTA) and communities on ongoing natural hazards management and how best to use the new findings. 
• Further work may include developing short-term action plans and utilising longer-term decision-making and funding processes (e.g. council’s Long Term Plans). 
• CDEM will update the Teviot Valley Emergency Response Plans to reflect the new findings and to raise awareness of facilities identified to support the community’s welfare needs. 
• Keep your eye out for updates in the Teviot Bulletin and orc.govt.nz/roxburghhazards (please share this link with interested people).