"The goal is to raise awareness about the opportunity to participate in regional water quality standards. We need citizens to be active and concerned."
Ms Delahunty said decades of data showed water quality had worsened in the past ten years. National standards revised last year set a bottom line for quality at wading and boating spots. The national standard allows regional councils to set higher levels for water quality - swimmable standards.
"Swimmable rivers is a bottom line for this country. Places like McLaren Falls are incredibly popular. You've been given a caution rating - so what are you going to do to clean it up?"
The Land, Air, Water Aotearoa website (LAWA) - a joint environmental resource - displays an orange caution circle for McLaren Falls. The website states "At times this site can be high risk (5 per cent or greater risk of illness)".
The Bay of Plenty Regional Council's website lists McLaren Falls as safe to swim, as measured on February 25, but it has a historical rating of "poor" based on tests done over the past five years.
Council science manager Rob Donald said, "Monitoring records show a history of elevated bacterial levels at this site after heavy rainfall events, most likely due to run-off from surrounding farmland and bird faecal matter."
Mr Donald said generally, water quality of lakes and open beach areas in the Bay was good. The highest risk, he said, is in rivers, streams and estuaries.
"We have a lot of urban development. And there are diffuse sources of contamination, whether overland flow or groundwater. We've moved dairy effluent discharges to land disposal. My personal view is there are lots of places to bathe in the Bay of Plenty that are perfectly safe."
Mr Donald said much of the costs of improving water quality involve livestock fencing and reducing discharge of effluent (Federated Farmers says 90 per cent of farmers near waterways have already fenced their properties).
"Over time things will improve, but it won't happen overnight," he said.
Data the Green Party provided to the Bay of Plenty Times Weekend from regional councils and other government authorities shows one monitored site in the Bay of Plenty - the Waimapu River at the Greerton Park Footbridge - had a "very poor" rating for 2012-2014.
Twelve other sites had "poor" ratings, including the Wairoa River below McLaren Falls Dam; the Wairoa River at Bethlehem and Kaiate Stream at Kaiate Falls.
Ms Delahunty said: "The problem is the government standard is for boating and wading - that's not good enough. Two-thirds of monitored freshwater rivers are not safe for swimming. The Government's still in denial about the seriousness of the problem."
Environment Minister Nick Smith disagrees.
"We have some water bodies in New Zealand that were never safe to swim in prior to human habitation and the Green proposal that every freshwater body has to improve would prevent some of the initiatives we have taken that have resulted in big gains in water quality."
Dr Smith said Lake Rotoiti was the cleanest it's been in 30 years, thanks to the Government's redirection of water from Lake Rotorua.
