Hawke's Bay Regional Council: http://www.hbrc.govt.nz/assets/Document-Library/Information-Sheets/Land/Protecting-your-Farm.pdf
Earthflow and slump erosion may be able to be addressed by spaced planting of trees in pasture, or where particularly severe, by close planting to give a forest cover.
Taranaki Regional Council: https://trc.govt.nz/assets/Documents/Guidelines/Land-infosheets/LM46controlearthflowerosion.pdf