All braided river estuaries and coastal lagoons/hapua throughout New Zealand will be affected in varying ways, depending on their location and catchments. The quote below was from a 2007 synthesis report. It’s dated, but current events underscore the rapid changes now taking place.
“Since 1950, there has been 0.4 to 0.7°C warming, with more heatwaves, fewer frosts, more rain in south-west New Zealand, and less rain in north-eastern New Zealand. New Zealand is already experiencing impacts from recent climate change… These are now evident in increasing stresses on water supply and agriculture, changed natural ecosystems, reduced seasonal snow cover, and glacier shrinkage.”
Heat in the atmosphere turbo-charges atmospheric weather events, leading to ‘weather bombs’. Storms become more intense, resulting in more frequent and more intense flooding. Droughts are outcomes and harsher with increased evapotranspiration. Winter snow pack and glacial mass in New Zealand is decreasing rapidly, leading to a change in river flows.
Reduction of greenhouse gasses (GHG) is required to reduce the speed at which weather is changing. Due to an escalating feedback loop of ice melt in the Poles, the weather will not ‘return to normal’ within our lifetimes.
As with rising sea levels, this area of research is moving at such a rapid pace, we have opted not to include specific links here. If you are looking for the latest peer-reviewed research on the topic, you might like to start with the journal Nature Climate Change.