Drought

Drought caused by longer periods of dry weather means less water to go around, with restrictions to supply becoming more common. That means there’s less for non-essential water use such as gardening or filling the paddling pool. We have seen this recently in Banks Peninsula where rainfall dropped to its lowest level in a decade, putting extra pressure on the water supply for communities there.

Long, dry periods place increased demands on agricultural irrigation to support plant growth. If water supply is limited, production will be affected, and prices of fruit, vegetables, meat and dairy products will likely increase. Warmer conditions can also make it harder to grow crops such as potatoes that prefer cooler growing conditions.

The availability and efficiency of irrigation water is critical for determining the type of land use, including where certain crops or pasture can be grown, especially as the effects of drought and availability of water will become more apparent. Less-efficient irrigation can affect production and drive up the price of produce for us all.

Impacts from droughts can ripple through districts affecting the environment, the health of a community and the economy. Areas that rely on rainwater for drinking and other uses like pasture growth can be especially hard-hit.

Drought significantly affects the water race networks, which are thousands of kilometres long and supplied by rainfall, snowmelt, rivers and springs. Some of our communities rely on this network for irrigation, supplying water to stock animals and for fighting fires.

Drought can deplete the water we have in storage, which means both urban and rural communities that rely on water from storage sourced from rainfall or streams/rivers may experience water restrictions.

Long-term drought affects the availability and quality of our drinking water as reduced stream and river flows can increase the concentration of pollutants in the water. During times of drought there is less urban and agricultural run-off/contamination, however, surface water can become stagnant during hot dry spells, and there can be increases in toxic algal blooms in both rivers and lakes. These blooms can cause problems for drinking water and contact recreation, and people who get their drinking water from their own wells may be more vulnerable to drought-related infectious diseases.

Wastewater can become more concentrated if there is less water in our pipes to dilute it, posing a threat to human health and ecosystems when it is discharged. Resolving this will require greater investment in wastewater treatment in the years to come.

Drought can significantly impact our native flora and fauna. Long dry periods can cause native trees to die and be replaced by more drought-tolerant introduced species, increasing the risk of wildfires. This directly reduces the food resources of species that are reliant on our native ecosystems to survive, putting the richness of our biodiversity at risk.

Increasing drought, and its impact on landscapes and biodiversity, poses a significant risk to Māori interests, values, practices and wellbeing. These impacts include a loss of mahinga kai, taonga species, access to culturally important plants and changes to geographical features that are integral to tūrangawaewae.

Taonga species are at risk from a range of climate change threats such as drought, flooding and sea level rise, with flow-on impacts to the availability of food and mahinga kai. Seeking out new opportunities for abundant food supply is already being identified as a high priority by iwi.