Last updated: August 30, 2023

Contact: ENV.Stat@oecd.org

Source for non-OECD countries: UNSD, Country Files from the UNSD/UNEP data collection on environment statistics (available at: https://unstats.un.org/unsd/envstats/country_files; Date of last update: 16 May 2023).

Australia: Long-term annual average 1985-2021. The outflow data represents the total river outflow to sea from the National Water Account regions only. It does not represent the total outflow to sea for all of Australia.

Austria: Long-term annual average 1986-2015

Belgium: Long-term annual average 2000-20

Canada: Long-term annual average 1971-2004

Chile: Long-term annual average 1985-2014

Colombia: Long-term annual average 1983-2016

Costa Rica: The long-term annual average refers to 2001-2021

Czech Republic: Long-term annual average 1991-2020

Finland: Long-term annual average 1981-2010

France: Long-term annual average: 1981-2010. Data exclude oversea territories. Inflow and outflow data exclude flows of underground water and of the Rhine river.

Germany: Long-term annual average 1991-2020

Greece: country-level aggregated data on precipitation and evapotranspiration is not yet available. Data refers precipitation heights (mm) at specific meteorological points/stations.

Hungary: Long-term annual average 1981-2010

Ireland: Long-term annual average 1981-2010. Inflow and outflow: data refers to flows of two main rivers crossing with Norther Ireland. Groundwater available for annual abstraction was estimated taking 10% of "Recharge into the Aquifer" (period 1971-2000). Freshwater resources 95% of years was estimated by taking the second lowest annual figure for "Total Renewable Freshwater Resources" over the previous 20 years.

Israel: Long-term annual average 2000-2013

Italy: Long-term annual average 1991-2020.

Japan: Long-term annual average 1986-2015

Korea: Long-term annual average 1967-2018. Data refers to the continental area (Jeju and Ulreung Islands are excluded).

Latvia: Long-term annual average 1961-2010. Water resources in lakes and reservoirs are not included in the volume of the total renewable freshwater resources

Lithuania: Long-term annual average 2000-2021. Evapotranspiration is measured only in one station, thus data may be biased.

Mexico: The long-term annual average covers the period 1981-2010 for precipitations, the other values are annual.

Netherlands: Long-term annual average 1991-2020. Evapotranspiration refers to potential evapotranspiration

New Zealand: Long-term annual average 1995-2020

Norway: Long-term annual average 1981-2010.

Poland: Long-term annual average 1981-2010.

Portugal: data on precipitation excludes overseas territories and evapotranspiration is potential, not actual.

Slovak Republic: Long-term annual average is 1961-2000

Slovenia: Long-term annual average is 1971-2000

Sweden: Long-term annual average: 1990-2020. For more information see https://www.smhi.se/data/hydrologi/vattenwebb/om-data-i-vattenwebb/kalibrering-och-utvardering-av-s-hype-1.26735

Switzerland: Long-term annual average: latest 21 years. The inflow from neighbouring countries cannot be precisely allocated to the river basins. The outflow is measured at relevant measuring points of the federal monitoring network. There are gaps and overlaps.

Türkiye: Long-term annual average: 2000-2021

Argentina: outflow to neighbouring countries excludes groundwater

Belarus: inflow from neighbouring countries excludes groundwater

Georgia: inflow refers to the sum of inflows from Armenia and Türkiye.

Moldova: Internal flow refers to the flow of small rivers, excluding Dniester and Prut; groundwater flow is excluded.

Ukraine : Data exclude Crimea.