A review of the purpose and benefits of forest drainage has indicated that drainage is unlikely to increase growth but may improve crop stability on wet sites. Drains are required to control the run-off of water from surface cultivation in order to reduce soil erosion and the movement of sediment to streams. This requires careful planning of the drainage system. On deep peat soils drain depth should be maintained but on mineral soils maintanance should be limited to the clearance of gross blockages.
