Wellington Report 2019: Capital's climate change reality - Slips, storms and flooding are on their way
The Wellington Report 2019 - six years on from the first version - takes an in-depth look across seven days at the city and region in terms of economy and employment, governance, housing, resilience, arts and hospitality, transport, and quality of life. Wellington faces more than its fair share of natural hazards, and as climate change takes hold, those risks are becoming more likely. Slips, storms and flooding are becoming more frequent and that will have big consequences for infrastructure, roading and housing. Wellington City Council chief resilience officer Mike Mendonca said the capital's biggest challenge is how to stop the climate crisis becoming even worse. Mendonca said when it comes to insurance - "the canary in the coalmine" - we're in trouble. * The taniwha is coming, and he's not welcome * Kapiti Coast - a community at the sea's mercy * Slips, storms and flooding are on their way * The quake is coming, but there is much hope * Different communities, different fears "We can expect to find insurance expensive or even inaccessible for some parts of the city. "Even if we manage to find affordable insurance, we need to take notice of what the insurers are telling us. "We need our planners, developers, insurers and decision-makers to work together to plan a city that knows how to live with these hazards." In the Wairarapa, there are other risks. Climate change means a heightened risk of drought, with risks for agriculture. Here are just some of the expected consequences for the region, with many already present and growing issues. SLIPS Slips will become more frequent in Wellington as extreme rainfall and storm events increase. A major slip could also change a road or cut off an important Wellington route entirely. While landslides are not new to Wellingtonians, slips in recent years had emphasised the vulnerability and the importance of good maintenance and earthworks management, Mendonca said Recent slips have occurred in Ngaio and Ngauranga Gorges , and a couple on private properties in Wellington's Southern suburbs and Oriental Bay. "These are all in the kinds of areas where we expect more challenges," Mendonca said. "We expect more landslides and more flooding as a result of more intense rainfall." STORMWATER AND FLOODING A 2014 report from the Intergovernmental Panel on Climate Change identified all of New Zealand as being at risk of flood damage to low-lying coastal infrastructure. Stormwater drainage challenges are already emerging in low lying parts of the CBD, Kilbirnie and Miramar, Mendonca said. Wellington's stormwater system is an underground network of pipes which drain the rain from roads, footpaths and gutters and diverts it to streams rivers and the sea. Dated stormwater systems are already being overwhelmed by rising sea levels in some parts of Wellington. Mendonca said in future, Wellingtonians will have to learn to live with more water. On private property the responsibility of stormwater lands on the property owner, and when it's not draining, flooding can cause erosion and the pollution of waterways. "We already know roughly where this [flooding] is likely to occur in fact it already does," Mendonca said. "In future, we're likely to be more worried about flooding of habitable spaces, and we will need to accept that flooding of garages, basements and gardens will be normal." SEA LEVEL RISE Ten per cent of the city's property values could be wiped out by a sea level rise . That's according to projections used as part of a Wellington City Council plan that aims to slash the city's carbon emissions to zero in 30 years. While global sea-level rise has been predicted to be between 0.28 and 0.98m by 2100, Niwa has noted that it could be "significantly greater" depending on the future behaviour of Antarctic ice sheet The council, however has been using a 1.4-metre sea level rise estimation, based on Ministry of Environment guidance, which computer models have shown could decimate Wellington's central city an area that drives 77 per cent of the city's economy. Beyond the capital city, sea level rise has the potential to impact the regions' other coastal communities and infrastructure, particularly in Lower Hutt and Kapiti. The Greater Wellington Regional Council, in a 2017 report, projected that sea level rise and consequent coastal strengthening would result in the loss of habitats, forcing local authorities to look at different adaptation strategies including restricting coastal development and managed retreat. Due to the Cook Strait and Wellington area's small tidal range, sea level rise was also set to have a greater influence on storm inundation and rates of coastal erosion than in other parts of New Zealand that have larger tidal ranges. DROUGHT Using Niwa data, the Greater Wellington Regional Council has projected drought events across the region will increase in both severity and frequency within the next 70 years. Increases would likely be most marked in already dry areas, particularly Wairarapa, where draught had the potential to reduce crop and pasture growth. Wairarapa would go from having about 24 hot days a year above 25 degrees to about 94 days. That meant, according to the council's 2017 Wellington Region climate change projections and impacts report, that crops may have to be sown earlier in the growing season and would reach maturity faster due to higher temperatures. Changes in temperature and rainfall also increased the likelihood of cattle being more susceptible to heat stress, as well as increasing the number of days of very high and extreme forest fire danger by 100-150 per cent across the region. A slither of optimism came with the report mentioning that warming temperatures could bring opportunities to grow different crop species. According to the Ministry for the Environment, compared to 1995, temperatures were likely to be 0.7 C to 1.1 C warmer by 2040 and 0.7 C to 3.0 C warmer by 2090. WHAT CAN BE DONE? Mendonca said it's time to get people out of petrol cars and into active and public transport. "Perhaps our biggest challenge is how to stop making the climate even worse. We need to change." If people really needed to use cars, they should switch to electric, he said. "Mostly, we need excellent public transport." But transport wasn't the only big issue to be faced head on. "We need to make out buildings more energy efficient and we need to change how we dispose of waste." BY THE NUMBERS 10: The percentage of the city's property values could be wiped out by a sea level rise . 0.28-0.98m: Global sea-level rise predicted by 2100. 1.4-m: Figure used in computer modelling for Wellington's sea-level rise. 77: Wellington city's contribution to the regional economy, in percentage terms. 94: Number of days above 25C each year in Wairarapa, up from 24 now. 100-150: Percentage increase in number of days of very high and extreme forest fire danger. 0.7 C to 1.1 C: Rise in temperature by 2040; 0.7 C to 3.0 C warmer by 2090. TOMORROW: Arts, hospo and fun - a look at the region's after-hours scene.