Water reuse can include reusing water from many sources. Sometimes it is used water from showers or dishwashing, and other times it is managing agricultural runoff. The Other names include “water recycling,” “water purification,” “reclaimed water does not need filtration if it is for plants (where the ,” “recycled water will not contact any edible parts). Although it can be filtered for use in washing ,” “reuse water, less often filtered for drinking ” and “repurified water, but with the appropriate filtration system, it is possible.”
Water reuse is a well-known concept and part of the [[3R (water) – Recharge, Retention and Reuse|3R process (recharge, retention, reuse)]]. In this way, managing water well is thought of as a "buffer" to insure consistent supplies - A buffer between the user and the bad effects of drought or an unreliable water resource.
Today, reclaimed water applications range from pasture irrigation, where minimal treatment is acceptable, to potable reuse, where extensive treatment is needed to meet drinking water standards. Agricultural irrigation continues to be the major use of reclaimed water in most developing countries. ===Three processes with groundwater that support reuse===
Three processes are important in managing reuse. '''The first is management of (non-beneficial) evaporation.''' Water that evaporates ‘leaves’ the system and can no longer circulate within it. This is an important concept. In some areas, for instance, ‘efficient’ irrigation reduces reusable recharge and results in the evaporation of a higher percentage of the water. This makes less water available for reuse and may jeopardize the water balance. One source of evaporation is from the soil – particularly from depressions and moist stretches. There is a fine balance between keeping good soil moisture (which is also achieved by agronomic practices, shade trees and the like) and avoiding evaporation losses from the soil. In fact, in some areas a reduction in groundwater table (from very high to moderate) reduces such non-beneficial evaporation.
By ponding up groundwater and slowing down lateral movement, retention can create or enlarge such saturated zones. These nuances must be appreciated in order to avoid the assumption that because a basin is a hydrological unit all water related processes in the basin are one and the same.
===Acknowledgements===
* [http://bebuffered.com/downloads/3R_managing_the_water_buffer_2010.pdf Managing the Water Buffer for Development and Climate Change Adaptation: Groundwater Recharge, Retention, Reuse and Rainwater Storage], Frank van Steenbergen and Albert Tuinhof.
* [http://www.watereuse.org/files/images/04-007-01.pdf Status and Role of Water Reuse], Global Water Research Coalition.
