Hump and hollow
The technique, used on peat soils and in areas of high rainfall, allows for faster water runoff and lowers the level the water table. In a three-year trial at Kowhitirangi on the West Coast of New Zealand where the annual rainfall is 3000mm, an improvement of 14% was made when compared with no drainage.
Hump and hollowing is increasingly used on the West Coast and concerns have been raised about the effects on water quality.  There is also an effect on soil structure, catchment hydrology, and modifications to habitat.
- "Getting the best out of hump-and-hollow farming". Water Resources Update No 14. NIWA. 2005. Retrieved 2008-04-17.
- Brown, Steph (2004). "Review of Humping and Hollowing on the West Coast" (PDF). Opus International Consultants. Archived from the original (PDF) on 27 September 2011. Retrieved 1 July 2011.