Physical Supply and Use tables (PSUT) SEEAW training New York, November 2006

Outline What do PSUT measure?What do PSUT measure? Basic definitionsBasic definitions Industry breakdownIndustry breakdown SEEAW standard tablesSEEAW standard tables Supplementary tables/informationSupplementary tables/information Breakdown of water flowsBreakdown of water flows Matrix of flows within the economyMatrix of flows within the economy Water losses in distributionWater losses in distribution

What do PSUT measure? PSUT describe in physical units The exchanges of water between the environment and the economy (abstraction and returns) The exchanges of water within the economy (supply and use within the economy)

Why compiling PSUT PSUT are important because They allow for the identification of the activities/sectors which put more pressure on the environmentThey allow for the identification of the activities/sectors which put more pressure on the environment They provides indication of the more consumptive useThey provides indication of the more consumptive use Together with monetary data, they provide information for water allocation policiesTogether with monetary data, they provide information for water allocation policies

Basic concepts and definitions Economic activity/ Households Use From the environment (abstraction) From another economic unit Supply To the environment (returns) To another economic unit Evapotranspire

PSUT By columns, industries, households and the Rest of the worldBy columns, industries, households and the Rest of the world By rows, types of flowsBy rows, types of flows SNA identity “Supply is equal to the Use” holds They consist of three part: Flows from the environment to the economyFlows from the environment to the economy Flows within the economyFlows within the economy Flows from the economy to the environmentFlows from the economy to the environment

Industry breakdown Standard PSUT distinguishes the following groups: ISIC 1-3 which includes Agriculture, Forestry and Fishing; ISIC 5-33, which includes: Mining and quarrying, Manufacturing and Construction; ISIC 35 ‑ Electricity, gas, steam and air conditioning supply; ISIC 36 ‑ Water collection, treatment and supply; ISIC 37 ‑ Sewerage; ISIC 38, 39, 45-99, which corresponds to the Service industries.

Industry breakdown ISIC 36 and 37 are key activities for the distribution of water and wastewater services ISIC 35 is a major user of water for hydroelectric power generation and cooling purposes: it abstracts and returns into the environment enormous quantities of water. Aggregating information on water use and supply by ISIC 35 with that of other industries would provide misleading information.

Industry breakdown ISIC does not classify according to the institutional sector (government, households, NPISH and corporations) to which a statistical unit belongs.ISIC does not classify according to the institutional sector (government, households, NPISH and corporations) to which a statistical unit belongs. Activities carried out by government units that are specifically attributable to other divisions of ISIC should be classified in the appropriate division of ISIC and not in division 84, ISIC Rev. 4.Activities carried out by government units that are specifically attributable to other divisions of ISIC should be classified in the appropriate division of ISIC and not in division 84, ISIC Rev. 4.

Flows from the environment to the economy

Basic concepts and definitions Abstraction is defined as the amount of water that is removed from any source, either permanently or temporarily, in a given period of time for consumption and production activities. Water used for hydroelectric power generation, is also considered as abstraction.

Abstraction Abstraction from soil water includes rainfed agriculture Collection of precipitation is the direct collection of precipitation for production and consumption activities (rain roof harvest) Abstraction from the sea includes the cases of water used for cooling purposes (the corresponding wastewater flow is generally returned to the sea or ocean) and for desalination processes

Flows within the economy

Water supply Water supply is recorded net of losses in distributionWater supply is recorded net of losses in distribution Water losses in distribution: volume of water lost during transport through leakages and evaporation between a point of abstraction and a point of use, and between points of use and reuse.Water losses in distribution: volume of water lost during transport through leakages and evaporation between a point of abstraction and a point of use, and between points of use and reuse. Losses in distribution may occur because of leakages and evaporationLosses in distribution may occur because of leakages and evaporation

Wastewater Wastewater: water which is of no further immediate value to the purpose for which it was used or in the pursuit of which it was produced because of its quality, quantity or time of occurrence. Wastewater can be discharged directly into the environment (return flow), supplied to a treatment facility (ISIC 37) (wastewater to Sewerage) or supplied to another industry for further use (reused water).

Reused water Reused water: wastewater delivered to a user for further use with or without prior treatment. Recycling within industrial sites is excluded. It is important to record this reused water as it can alleviate the pressure on water resources by reducing direct abstraction of water.

Flows from the economy to the environment

Standard PSUT

Water Use Water use: water intake of industries and households for production and consumption activities. Water Use is the sum of water use within the economy and water use from the environment. Water use within the economy: water intake for production and consumption activities, which is distributed by industries or households and by the Rest of the World (Imports). Water use from the environment: water abstracted from water resources, seas and oceans, and precipitation collected by industries and households for production and consumption activities, including rainfed agriculture.

Water Supply Water supply: water leaving/flowing-out from an economic unit (Industries, Households and rest of the world). Water supply is the sum of water supply to other economic units and water supply to the environment. Water supply to the environment (also Water returns): water returned into the environment during a given period of time after use. Returns can be classified according to the receiving media (i.e. water resources and sea water) and to the type of water (e.g. treated water, cooling water, etc.). Water supply within the economy: water distributed to households and industries (including agriculture) and to the rest of the world (exports). Water supply within the economy is net of losses in distribution.

Water consumption Water consumption: part of water use which is not distributed to other economic units and does not return to the environment (to water resources, sea and ocean) because during use it has been incorporated into products, consumed by households or livestock. It is calculated as a difference between total use and total supply, thus it may include losses due to evaporation occurring in distribution and apparent losses due to illegal tapping and malfunctioning metering It is calculated as a difference between total use and total supply, thus it may include losses due to evaporation occurring in distribution and apparent losses due to illegal tapping and malfunctioning metering

Supplementary information (1) Abstraction for own use Hydroelectric power generationHydroelectric power generation Irrigation waterIrrigation water Mine waterMine water Urban runoffUrban runoff Cooling waterCooling water OtherOther

Supplementary information (2) Use of water received from other economic units Reused waterReused water Supply of water to other economic units Desalinated waterDesalinated water

Supplementary information (3) Matrix of flows within the economy

Supplementary information (4) Tables on losses in distribution