A project to monitor river pollution using aircraft drones is to be launched this month.
Known as Riverwatch, it has been developed by Wairarapa farmer and artist Grant Muir and his film-maker son, James, with the help of Victoria University's school of engineering and computer sciences.
The electric-powered drones, or unmanned aerial vehicles, will follow a pre-set course along rivers, filming from a nose-mounted camera and taking still photographs from a belly camera.
They will have a 40-kilometre round-trip range.
When animals are found beside or in rivers, or signs such as hoofprints are seen, the GPS (global positioning system) co-ordinates will be noted.
In development are the use of thermal imaging and miniature helicopters to take a closer look at sites of interest and to collect water samples.
The evidence will be posted on Riverwatch's website, which will be launched later this month.
The public will also be able to contribute to the website, through a phone app that attaches GPS co-ordinates to photographs and allows comments to be added before sending them to the site.
If the photographer is out of cellphone range, the information will be stored and sent when they are back in range.
Grant Muir's battles to clear wandering cattle and sheep from the waters of Wairarapa's remote Pahaoa River were filmed by James in River Dog, a half-hour documentary which has won awards in Britain, Spain and New Zealand.
Riverwatch's purpose was not to beat up farmers, Grant Muir said. "No matter how good the intentions of conservationists, farmers, Fonterra and the dairy industry, we don't have an effective way of monitoring what's going on in the rivers. We know there's pollution - we can't pinpoint where it comes from."
His aim was to use the drones, which he had imported in kitset from the United States, to extend river monitoring from flatland dairying to the hills.
"What we found with River Dog is that a lot of the farmers who do not support clean rivers live in isolated areas. This will take those areas out of their isolation and put them out there for all to see."
He was driven to act after seeing changes in the Pahaoa River. "I hope we're in time with this. In 2002, the Pahaoa was full of fish, now they wash up dead."
An attempt last year to set up a nationwide river patrol scheme fell through because canoes could not always get into isolated areas.
The drones would not fly over homes or farms.
"It will be a fantastic tool to make the farming industry better, more compliant. It will be able to gauge what difference their efforts are making." It could also be used to demonstrate what was being done to keep rivers clean, showing fencing and riparian strips.
"We're hoping we're going to give Fonterra, Federated Farmers and the regional councils a tool they can use to monitor water resources at a fraction of the cost of getting someone to drive around the countryside or to go up in a helicopter."
- The Dominion Post