Most of the 100-year flood extent (Figure 1) is identified as lower flood hazard (yellow), meaning floodwater is likely to be shallow (less than 30 centimetres), relatively slow moving and not likely to affect people’s safety, vehicle access and building structural stability. Shallow flooding of buildings may still occur in these areas. This depends on the building floor level and local features, such as fences, affecting the overland flow paths.  

Floodwater is more likely to affect people’s safety and vehicle access in higher flood hazard (blue) areas; and is also possibly unsafe to buildings within and adjacent to the creek channels. The results also indicate the potential for local areas of deeper or faster-moving floodwater, including along some roadways. 

The study is not intended to assess flood hazard for individual properties, and further detailed assessment will be required for future development proposals in some areas. 

This is a planning-level study.  The new information should be viewed as indicative rather than as an exact boundary. The results are not intended or suitable to assess flood hazard for individual properties. They must not be used for flood hazard assessment at the individual property level.  

The new flood hazard information improves the understanding of where flooding may occur for a range of flood events and helps to answer general questions from the community about flooding.   

This study has several limitations, which are important to understand: 

• Detailed modelling of the storm sewer network, culverts and bridges was not included. 
• The flood model could not be checked against measured flood levels from past flood events because this information is not available for the Muddy Creek area. 
• The study did not include a detailed assessment of how rainfall across the wider catchment may influence flood flows in Muddy Creek. 
• A ditch along State Highway 1 carries flow from the adjacent catchment (south of Landon Creek) into the Muddy Creek catchment. There is uncertainty about the magnitude of this inflow during floods. 

During an actual event, it is common to get local obstructions and blockages that affect surface flooding in developed areas. 

Insurance companies use a wide range of information when assessing risk, and hazard studies are one possible source of information used in those assessments. 

The purpose of the study is to inform Waitaki District Planning process and improve general understanding of how flooding may occur. The limitations and uncertainties of the study mean that the results are not suitable for property-specific hazard assessment and must not be used for this. 

Otago Regional Council (ORC) does not make decisions about insurance cover or premiums. Questions about individual insurance policies should be discussed directly with insurance providers or brokers.

The new flood information does not automatically affect future development. It does help identify: 

• where flooding may occur, and 
• where additional flood assessment may be needed before future development is considered. 

Some undeveloped areas may require further flood assessment if development is proposed in the future. 

Redevelopment of an existing site may be able to rely on existing use rights; however, the developer/owner may wish to elevate the building to future proof it. 

No one is required to move away. This kind of flooding is common on floodwater-dominated alluvial fans and has been identified in other Otago communities.  

Most flooding identified in the new flood hazard study is expected to be low hazard, meaning floodwater is generally expected to be shallow and relatively slow-moving, and unlikely to cause structural damage to buildings.  

The highest hazard areas are within and adjacent to the creek channels and in local pockets of deeper or faster floodwaters.   

If you are concerned about possible flood impacts, you may want to consider ways that your household or business can reduce flood damage (such as flood proofing) and increase awareness and resilience (such as flood action plans). 

Community feedback and local knowledge are important parts of understanding how flooding may occur in the Muddy Creek area. 

If you have questions or feedback about the new flood hazard information, ORC encourages you to: 

• attend the community drop-in session on 25 June 2026 (more information is available on the event page)  
• discuss your concerns with ORC staff
  • 0800 474 082 or email customerservices@orc.govt.nz