| Available water | The total exploitable water minus reserved flows. It represent the water that is available for use at the domain |
| Beneficial consumption | Water consumed for the intended purpose |
| Closed basin | A basin where utilizable flows are negligible small |
| Committed flow | Water that has been allocated for a special purpose such as an interbasin transfer or cross–boundary flow. Often decrees and acts legally describe the agreed flows between one or more parties |
| Consumptive use | Water withdrawn for an intended process that does not return back into the basin, except from atmospheric recycling; it relates to evapotranspiration, water pollution and water incorporated in products |
| Demand | Amount of extra water needed to supplement naturally available water |
| Ecosystem services | There are four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as spiritual and recreational benefits |
| Environmental flow | Minimum river flow required for maintaining the biodiversity of riverine ecosystem including endangered fish species and the riparian corridor |
| Evapotranspiration | Energy process that converts water from liquid to gaseous phase. EvapoTranspiration (ET) occurs as interception evaporation, soil evaporation, water evaporation, canopy transpiration. ET occurs outdoor |
| Gross inflow | The total amount of water that flows into the domain, this includes precipitation plus any inflow from surface or ground water sources and desalinized water |
| Incremental ET/ Blue ET | Enhancement of evapotranspiration (ET) due to rainfall by supplying additional water resources |
| Interception | Evaporation of a thin water film from wet leaves or other wet impermeable (artificial) surfaces |
| Rainfall ET/ Green ET | Water from rainfall that evaporates locally from leaves, litter, soil, and via plants that extract moisture from the unsaturated zone |
| Managed water use | Represents land use elements with anthropogenic regulation of withdrawals and water supplies. It includes water withdrawals for irrigation, aquaculture, domestic use and industries, among others |
| Modified land use | Represents land use elements where vegetation is replaced with the intention to increase the utilization of land resources. Examples are plantation forests, pastures and rainfed crops, among others |
| Net inflow | The gross inflow after correction of storage change (ΔS). It represents water available for landscape ET and exploitable water |
| Non–beneficial consumption | Water consumed for purposes other than the use |
| Non–conventional ET | ET that occurs by non–natural processes such as steam from cooling towers, respiration by humans and animals, sweating and turbine spray, among others |
| Non–recoverable flow | Non–consumed water that is lost to further use, by pollution that exceeds international standards, flows to saline groundwater sinks, deep aquifers that are not economically exploitable or flows to the sea |
| Water productivity | the physical mass of production or the economic value of production measured against consumptive use water |
| Protected land use | Environmentally sensitive land uses and natural ecosystem that cannot be modified due to protective measures |
| Recoverable flow | Non–consumed water that can be captured and reused in streams, rivers, lakes, reservoirs and aquifers |
| Renewable water resources | Difference between rainfall and landscape ET for a river basin across a certain period. It is essentially the exploitable flow |
| Reserved flow | Surface water that has been reserved to meet committed flows, navigational flows, and environmental flow |
| Sink | Area where non–consumed and non–recoverable water ensembles |
| Supply | Provision of water withdrawn from a source to a certain user |
| Total water stocks | Represents water being present in reservoirs, rivers, lakes and groundwater that can be used for withdrawals |
| Utilized land use | Represents land use classes with a low to moderate utilization of natural resources, such as savannah, woodland and mixed pastures |
| Utilized water | Part of available water that is depleted for uses |
| Utilizable water | Water available for additional resources development |
| Water audit | Mapping the infrastructure and management of water systems, along with their socio–economics and financial conditions, as well as the legislations and institutions |
| Water governance | Political, social, economic and administrative systems that are in place, and which directly or indirectly affect the use, development and management of water resources and the delivery of water service delivery at different levels of society |
| Water use | any water flow related to a specific purpose. It can be related to both withdrawals and consumptive use and is a very broad (and confusing) term |
| Water withdrawals | Water taken away from a water source, either natural (e.g. inundation, leakage) or artificial (i.e. pumping, diversions) |
