Climate change

Our climate is changing, and more extreme weather and sea level rise will impact the ability to effectively drain the Waitarakao Washdyke catchment long-term.

Higher mean air temperatures are likely to raise the water temperature of waterbodies within the catchment. Climate change projections indicate an increase in rainfall intensity in the area, which will increase the occurrence of flooding and stormwater runoff. This will lead to additional inputs of nutrients, contaminants and sediment to the waterbodies. Higher water temperatures will increase the risk to native freshwater diversity as some species are sensitive to temperature increases. Warmer water temperatures could further alter water quality by contributing to algal blooms.

The coastline of Washdyke Waitarakao is eroding and sea level rise is projected to increase coastal erosion rates.

Coastal erosion will squeeze and degrade coastal and wetland habitats where geographical constraints or existing land use don’t allow a natural landward migration of coastal habitats. Sea level rise will also increase the frequency and size of coastal storm flooding, increasing the flood risk to built environments, productive land and coastal wetland habitats.

More coastal flooding will lead to increasing salinity stress to coastal wetlands. Many species of invertebrates, some species of plants, and fish species are specifically adapted to coastal wetland conditions and cannot tolerate large changes in salinity. This could result in a loss of biodiversity and/or changes to the composition of wetland species.