"Freshwater policies developed over at least the last 10 years in New Zealand have moved further from their scientific underpinnings with each new iteration.
"I will demonstrate this departure using examples from the National Policy Statement for Freshwater Management," he said.
As well as receiving a number of awards, Joy has published numerous papers in scientific journals, many international, as well as articles and op-eds for newspapers and magazines.
He has authored reports for regional councils and the Ministry for the Environment, and has developed a number of bio-assessment tools and associated software used by many North Island regional councils.
In this presentation he will show how many of the attributes measured under the title of "water-quality" in New Zealand are not fit for purpose, do not give logical assessments and are out of date given changes in technology.
Joy mainly draws on data from the Manawatu Region showing how none of the attributes in freshwater policy could possibly achieve the aims outlined.
"This means current freshwater policy is not making the difference needed," he said.
"Also, despite a recent revision of NPS parameters, varied health measures are reported for New Zealand's lakes and rivers."
All are welcome to attend at October 18 at 5.30pm at the Lake Taupō Rotary Club at 12 Story Pl in Taupō.