Impact of Urbanisation on New Zealand Freshwater Quality

Abstract

Urban waterways represent less than 1% of the total river length in New Zealand. However, they are the most visible of all rivers, as 86% of New Zealanders live in urban areas. Urban waterways are impaired due to elevated levels of pathogens, turbidity, nutrients and heavy metals originating from anthropogenic activities. In addition to being conduits of storm water run-off from urban areas, some urban waterways also receive discharges from wastewater treatment plants and combined sewage overflows, thus greatly reducing their capacity to provide ecosystem services such as recreation, tourism, biodiversity and mahinga kai. This article summarises the state of New Zealand’s urban freshwater quality, the major drivers of pollution, and mitigation measures needed to restore urban waterways.