"This campaign ... represents a great opportunity for all Kiwis to set aside their differing views and celebrate WCO waterways - jewels in the crown of this country's natural landscape which have been protected for all New Zealanders to enjoy and which are vital to our '100 per cent Pure, clean green' brand."
Oliver will be an ambassador for the campaigners, who will erect signs identifying WCO-protected rivers and lobby for WCOs to be strengthened in law.
Environmental Defence Society (EDS) chair Gary Taylor said water conservation orders were the only effective mechanism available to protect freshwater.
"EDS particularly supports moves to examine how land use adjacent to wild and scenic rivers can be better regulated to limit its impact on water quality," he said.
The Green Party and United Future welcomed the launch of the campaign yesterday.
Green Party water spokeswoman Eugenie Sage argued that the Resource Management Act should be amended to make WCOs permanent and ensure land use adjacent to rivers was managed to protect water quality.
At present, there were 15 WCOs for New Zealand's rivers.
But a report by the Parliamentary Commissioner for the Environment published in May showed only four applications for WCOs had been made in the past 21 years, since the orders were included in the Resource Management Act, and only two had succeeded.
This was mainly because the process was lengthy and expensive, and only large organisations such as Fish and Game could afford to make applications.
Commissioner Jan Wright pointed out that the scenic Mohikinui River on the South Island's West Coast, recently spared from a hydroelectricity project, was still vulnerable to harmful development because it flowed through loosely protected Crown land.
Developers faced an easier test to get access to land around the Mohikinui because the Department of Conservation only had "stewardship" rights over it.
Other precious rivers such as the Kaituna in Bay of Plenty and the Clarence in Canterbury were similarly vulnerable.
Dr Wright recommended that the Minister for the Environment identifed important rivers running through stewardship land and reclassifed the land where necessary.
WATERWAYS PROTECTED BY WATER CONSERVATION ORDERS
North Island:
Motu River
Mohaka River
Manganui o te Ao River
Rangitikei River
Lake Wairarapa
South Island:
Motueka River
Buller River
Grey River
Rakaia River
Lake Ellesmere
Rangitata River
Ahuriri River
Kawarau River
Oreti River
Mataura River