Assessments of stock losses and flood damage suffered by farmers in the Lower Buller Gorge, Inangahua, Reefton, Shenandoah and Maruia are underway.
Federated Farmers West Coast president Bede O'Connor estimated at least 30-40 farms had been significantly damaged by a combination of flooding and slips. Others suffered when streams, tracks and culverts blew out.
For some farmers it was the second time in seven months they had lost roads, tracks, fences and feed, and had their paddocks covered in silt, O'Connor said.
Farms on both sides of the lower reaches of the Buller River were not as badly affected as last July, but heavy silting covered paddocks in the Nine Mile and on land beside the river.
Farmers everywhere were reporting extensive damage to farm infrastructure, particularly in and around the Inangahua and Reefton area, O'Connor said.