Last November's powerful 7.8-magnitude earthquake has altered the course and flow of the Clarence River in southern Marlborough.
The changes to the lower reaches of river have caused flooding to farmland, uplifted strips of land by up to eight metres and created new rapids.
Woodbank farmer John Murray has about 15 kilometres of river boundary.
"The flat's been taken out, a very fertile bit of land for lamb finishing that was all in lucerne. There's 60 hectares there and we've probably lost 20," he says.
He can no longer use his land on the south side of the river either because the local class one bridge was destroyed in seconds by the earthquake.
Adventure tourism operator Clarence River Rafting has been severely affected by the earthquake because of the closure of State Highway 1 north of Kaikoura, but the new river rapids are a growing attraction.
The most striking is a section downstream of the destroyed bridge, which has been transformed into a seething stretch of white water.
Rafting guide Genevieve King is relishing the opportunity to explore the new features created by the disaster.
"There's parts of the river we can't raft now, so we have to get the boats down another way, walk the clients round and then jump back in. But for us it's turned into a great training ground on our back doorstep!" she says.