Wairarapa people were among 12,000 supporters of a petition to make New Zealand's fresh waterways "swimmable".
Supporters of Choose Clean Water arranged blue paper water drops to form a river at the steps of Parliament on Tuesday with each representing a signature on the petition.
Wairarapa artist Sam Ludden said he and his family signed when the campaign toured Wairarapa earlier this year.
The campaign calls for the Government to set its recently-introduced "bottom line" standards higher, so future generations would one day be able to swim at favourite spots again.
About two thirds of monitored freshwater sites in the country remain unsafe for recreational contact.
Mr Ludden, a keen kayaker and eeler, has been "mucking about" in Wairarapa rivers since he was a kid.