This report is a strategic assessment of New Zealand’s freshwaters for recreational use from a human health perspective. It outlines the methods used to produce spatial predictions of E. coli and cynobacterial biovolume at unmonitored locations. The methods used to prepare the water quality variables data, make assessments of the representativeness of the monitoring sites, and to undertake the spatial modelling are described.
The results provide national maps of river E. coli, lake water quality and cyanobacterial biovolume. Measures of model performance and the important relationships between water quality variables and predictors are described and discussed.