South Canterbury needs to prepare for coastal erosion, climate change
Coastal erosion and sea level rises could become a "fact of life" for Canterbury residents - and that includes South Canterbury - as climate change begins to bite, but councils are adamant they have prepared for it. National Institute of Water and Atmospheric Research (Niwa) climate scientist Scott Stephens said Caroline Bay's sea level is due to rise by a minimum of 30cm over the next 30 years, which will place greater pressure on infrastructure and on coastal properties. "Timaru is a coastal town, there are some fairly low-lying areas which will be vulnerable. Rather than big, really severe coastal flooding events, we will see a big increase in smaller flooding events," Stephens said. "It's important to realise that coastal adaptation is going to be a difficult problem for councils, but it needs to happen, and it needs to be done on a local scale." READ MORE: * Sea level rise expert delivers global warming warning * Powerful new supercomputer ready to provide glimpse into NZ's climate future * Sea inundation could affect nearly 25,000 Christchurch properties by 2120: new report Stephens' comments come in the wake of Local Government New Zealand (LGNZ) issuing a wide-ranging report on climate change and the potential effects on infrastructure. The report says local councils are facing a $5-8 billion bill to replace vital infrastructure lost to climate change in the next half-century. "It's about picking a series of pathways," Stephens said. "It's important that further development doesn't make the problem worse in the future. We need to be careful that we don't make decisions now that would make adaptation even more costly in the future." Stephens said housing, in particular in coastal areas, will become increasingly fraught. "As sea levels rise, we need to look at how we adapt our land use. It's really important that councils start to think about it now." Timaru District Council group manager for infrastructure Ashley Harper said the council had a 50-year infrastructure plan in place as part of its long term planning processes. "This underlines the importance of considering climate change effects in planning long life infrastructure. There are also effects from the planning point of view, which will be looked at as part of the District Plan Review," Harper said. "Climate change is likely to have a wider range of effects than just sea level rises, ranging from coastal erosion to changes in weather patterns, and will have an effect on everything we do from planning and building to infrastructure. "The majority of our infrastructure is positioned in a way that we can handle a moderate level of sea rise." Harper said the council provided data to the LGNZ report. "We undertook a stocktake of various infrastructure, which shows that at a 1.5m sea level rise, around 3 km out of 1959km of our water supply pipelines and just over 2km out of 952km of our sealed roads would be impacted," Harper said. "Some of the earliest effects would be seen at Caroline Bay Beach, which sits at just above sea level, and would be one of the first areas affected by any rise in sea level." Environment Canterbury chairman Steve Lowndes said "much of the work we do is understanding the effects of coastal hazards and the coastal drivers of those hazards, such as waves and storm tide levels". "We do this through our coastal monitoring programme (within the Coastal Hazards and Environment Programme in the Long-Term Plan), which involves intensive ongoing measuring of shoreline change and long-term collection of sea level and wave information in project partnership with NIWA," Lowndes said. Lowndes said ECan had a budget of $400,000 to monitor the effects of coastal hazards and the coastal drivers of those hazards, such as waves and storm tide levels. "Vulnerable areas in South Canterbury will be locations already experiencing coastal erosion, such as the Washdyke-Waitarakao/Seadown coast, Patiti Point, cliffs along St Andrews and the Morven-Glenavy coast." St Andrews resident Daphne Staats said coastal erosion was a "fact of life" for her. "It's usually after a good storm that the sea comes rising up that it starts eroding," Staats said. "We'd tried planting stuff at the boundary. We had deep-rooted plants at the top of the cliff, but they're disappearing. There really isn't anything we can do. It's an ongoing thing. We were aware of the erosion issue before we bought the place five years ago." Waimate District Council Assets Group Manager Dan Mitchell said the council was "acutely aware of climate change". "Remarkably little council owned infrastructure is likely to be affected by sea level rise within the district. Climate change, and the associated higher intensity rain events, will undoubtedly lead to more surface flooding but this is being addressed through programmed renewals and our Infrastructure Strategy," Mitchell said. Local Government New Zealand president and Dunedin mayor David Cull said he was concerned that councils and central Government had not adapted quickly enough to climate change. "The cost of adaptation will be considerable. Communities are becoming more and more frightened about coastal erosion and sea level rises," he said.