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.
He is best known for his clay eels art, which he makes both to evoke childhood memories and to raise awareness of the plight of the longfin eel.
"I didn't realise how privileged my upbringing was until I travelled overseas and saw the degradation of some European and English rivers," he said.
"I spent about six years overseas and when I came back in 2001, the rivers here weren't what I remembered.
"Under our noses over the last 10 years, the state of our local rivers has changed drastically. It's frightening how much it has changed.
"The rivers are under attack and we need to change things quickly, and I mean from the top.
"There's not really anyone advocating for rivers but that's changing. The Choose Clean Water movement is strong."
Campaign co-ordinator Marnie Prickett hopes the legislation changes and "that we make a national commitment to keeping our fresh water clean and healthy".
She spoke to Wairarapa man Grant Muir on the tour - "he's the guy who spent four years using cattle dogs to run cattle out of the local river," she said.
"Grant is a really lovely passionate Wairarapa guy. There was a movie made about him and what he did called River Dogs - it's the most epic story.
"When we went out to Pahaoa River to visit him in January on this tour we swam in that river.
"We wouldn't have been able to do that if it wasn't for him."
Greater Wellington Regional Council data shows 68 per cent of popular Wairarapa swimming sites have a low or very low risk of illness associated with them.
For more articles from this region, go to Wairarapa Times-Age