Key Takeaways
- Almost 18,000 properties across Wairarapa are estimated to be at risk in the event of a severe flooding event.
- The numbers are broken down as 3100 properties in Carterton, 9400 properties in Masterton, and 5300 properties in South Wairarapa.
- Climate change is expected to increase the frequency and intensity of severe weather, leading to a higher number of properties at risk.
- The Greater Wellington Regional Council (GWRC) is working on various flood management projects, including the Waipoua urban reach and the lower Wairarapa valley development scheme review.
- The council has also conducted a detailed flood damages assessment for Masterton, estimating damages between $8.1 million and $16.7 million for present day and $21.5 million and $42.3 million with climate change.
Introduction to Flooding in Wairarapa
The Wairarapa region is prone to flooding, with almost 18,000 properties at risk in the event of a severe flooding event. This number is expected to increase due to climate change, which is already changing the frequency and intensity of severe weather. The Greater Wellington Regional Council (GWRC) has revealed that the exact figure of 17,800 properties at risk breaks down regionally as 3100 properties in Carterton, 9400 properties in Masterton, and 5300 properties in South Wairarapa. These numbers include both rural and urban properties and are likely to increase as residential developments continue to be granted consent within known flood-prone areas.
Climate Change and Flooding
Climate change is a significant factor in the increasing risk of flooding in Wairarapa. Lian Butcher, GWRC’s group manager environment, stated that climate change modelling suggests that the effects of climate change will increase in the future, with nearly 50% of all buildings in South Wairarapa and Masterton districts exposed to flooding by 2110. This represents approximately 60% of commercial buildings in South Wairarapa and 70% of commercial buildings in Masterton. The council has also estimated that by 2110, both districts will have nearly 50% of all residential buildings exposed to flooding, which is a significant concern for the region.
Flood Risk Management
The GWRC plays a key role in managing flood risk, including modelling, risk management planning, emergency management, and the construction and maintenance of flood defences. The council has several flood management work programmes underway in Wairarapa, including the Waipoua urban reach project, which involves working with community members, mana whenua, and Masterton District Council on a preferred flood risk management option for the urban reach of the Waipoua River. The council is also reviewing the feasibility of using nature-based solutions for addressing flood risk to Masterton and the lower Wairarapa valley development scheme.
Flood Damages Assessment
The council has conducted a detailed flood damages assessment for Masterton, which estimates damages between $8.1 million and $16.7 million for present day and $21.5 million and $42.3 million with climate change. These estimates are based on a range of damage curves and take into account various factors, including buildings, vehicles, contents, clean-up costs, relocation, and rural areas. The assessment highlights the significant economic impact of flooding on the region and the need for effective flood risk management strategies.
Flood Resilience Projects
Following Budget 2024, the GWRC and the Ministry of Business, Innovation and Employment’s regional economic development and investment unit, Kānoa, agreed to co-fund 16 flood resilience projects as part of a nationwide initiative. The programme spans 15 sites across Wairarapa and one in Ōtaki, which are critical in future-proofing community, infrastructure, cultural taonga, and the economy following a major flooding event. These projects aim to enhance the region’s resilience to flooding and mitigate the impacts of climate change.
Conclusion
In conclusion, the Wairarapa region is at significant risk of flooding, with almost 18,000 properties at risk in the event of a severe flooding event. Climate change is expected to increase the frequency and intensity of severe weather, leading to a higher number of properties at risk. The GWRC is working on various flood management projects, including the Waipoua urban reach and the lower Wairarapa valley development scheme review. The council has also conducted a detailed flood damages assessment for Masterton, highlighting the significant economic impact of flooding on the region. The co-funding of flood resilience projects is a positive step towards enhancing the region’s resilience to flooding and mitigating the impacts of climate change.