The Havelock North water supply was most likely contaminated with the faeces of sheep grazing in the area around the bores on Brookvale Road. Evidence for this was provided by a detailed molecular analysis that linked the genetic signatures of Campylobacter present in the sheep faeces, with the drinking water supply and human cases. This talk will present recent information on the prevalence of potential waterborne pathogens, such as Campylobacter spp., Shiga toxinproducing E. coli, Cryptosporidium spp. and Giardia in pastoral livestock, surface and groundwater in New Zealand. It will also illustrate how genetic typing of pathogens helps us link water to human health impacts, through both drinking and recreational exposures. The implications of changes in livestock production, waste disposal and climate change on public health will be discussed The talk will refer to the latest surveys and epidemiological studies, combined with our application of genetic typing, including whole genome sequencing, of potential waterborne pathogens in New Zealand.