High Quality Content by WIKIPEDIA articles! Well drainage means drainage of agricultural lands by wells. Agricultural land is drained by pumped wells (vertical drainage) to improve the soils by controlling water table levels and soil salinity. Subsurface (groundwater) drainage for water table and soil salinity in agricultural land can be done by horizontal and vertical drainage systems. Horizontal drainage systems are drainage systems using open ditches (trenches) or buried pipe drains. Vertical drainage systems are drainage systems using pumped wells, either open dug wells or tube wells. Both systems serve the same purposes, namely water table control and soil salinity control . Both systems can facilitate the reuse of drainage water (e.g. for irrigation), but wells offer more flexibility. Reuse is only feasible if the quality of the groundwater is acceptable and the salinity is low.