She was also spurred on by the immense interest in her first book, Ravaged Beauty; An environmental history of the Manawatu.
"My first book was about where I came from ... with some digging came a series of revelations. From footprints of extinct moa to the remnants of an exiled Danish prime minister."
She then sought advice from Professor Tom Brooking, a leading environmental historian, who suggested rivers as the focus of her second book, filling a gap in the knowledge available around fresh water debate.
The book delves into the relationship between human activity and rivers, and how we've come to what some call a crisis point.
Dr Knight covered the dawning of the preservation era and finished with details about the wild and scenic rivers of the 1980s.
"In the early 20th century rivers were regarded as wild. These rivers made New Zealand unsuitable for shipping but made excellent drains."
She said sites such as the Golden Pah Mine discharged various sorts of waste into local rivers, which many at the time believed was simply pushed out to sea, causing no harm.
But decades later the realisation came that many historic practices have contributed to the state of New Zealand's rivers today.
Dr Knight also spoke of the prevalence of rivers as machines post-war, and the ignorance of Maori values when these were erected. As far back as the 1880s, people had been concerned about the need to address river health, she said.
"But this was more about fish ... rather than the ecological state."
Dr Knight also touched on the agricultural pressure contaminating rivers but said people were now more equipped to address the issues affecting water quality.
"The knowledge we have know ... is incomparable with what people had back then. I think now more than ever, New Zealanders want to be part of the discussion around healthy rivers."
In her book, she quotes Ngai Tahu kaiwhakahaere (chair) and co-chair of the Freshwater Iwi Leaders Group Mark Solomon who questioned the wadeable versus swimmable standards, describing them as ridiculous.
"When a child goes down to the river, they don't stop and say, "Is this river wadeable or swimmable?" They jump!"
Dr Knight said recent debate appeared to show New Zealanders wanted swimmable rivers, at least as an end goal.
New Zealand's Rivers; An environmental history, Canterbury University Press, orders and enquiries to www.nationwidebooks.co.nz or catherineknight.nz
