FAO Provides Guidance on Environmental Flows as a Measure of Water Stress
UN Photo/Victoria Hazou
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The publication outlines the scope of data that would support a calculation of environmental flows.

The scope includes river flow variability, river connectivity, ecosystem services and human well-being, as well as consideration of the overall ecological management class of a given river system.

4 February 2019: The Food and Agriculture Organization of the UN (FAO) has issued guidelines on environmental flows to assist countries in managing levels of water stress. SDG target 6.4 sets out the aim of ensuring sustainable withdrawals and supply of freshwater to address water scarcity, and SDG indicator 6.4.2 measures water stress in terms of freshwater withdrawal as a proportion of available freshwater resources.

FAO launched the publication titled, ‘Incorporating Environmental Flows into “Water Stress” Indicator 6.4.2: Guidelines for a Minimum Standard Method for Global Reporting,’ at its headquarters in Rome, Italy, on 29 January. The report is a collaboration between FAO, the International Water Management Institute (IWMI), the UN University (UNU), and the UN Environment Programme (UNEP) and its Integrated Monitoring of Water and Sanitation-related SDG Targets (GEMI) initiative, coordinated by UN-Water.

Countries report on environmental flows as part of their VNRs to the HLPF.

According to the authors, countries in Western Asia, Central Asia and Northern Africa currently experience a 60% rate of water stress, which fluctuates in severity depending on the season. The 32-page publication outlines the scope of data that would support a calculation of environmental flows. The scope includes river flow variability, river connectivity, ecosystem services and human well-being, as well as consideration of the overall ecological management class (EMC) of a given river system.

FAO suggests that, for countries with less capacity to undertake detailed assessments, simple methods for estimating environmental flows are acceptable, for example, using look-up tables or undertaking desktop analysis of time-series hydrological data and, if available, ecological data. The Agency recommends, where possible, more complex approaches, based on site visits and engagement with stakeholders and local experts, acknowledging however that these require more time and may not provide definitive estimates at the national level for all rivers.

FAO regularly produces global-level data on water stress, which countries then either validate or replace with more reliable, “higher confidence” data. Countries report on environmental flows as part of their Voluntary National Reviews (VNRs) to the High-level Panel on Sustainable Development (HLPF), as part their self-assessment of progress towards achieving the SDGs.

Water stress of less than 25% is considered low, and water stress of more than 70% is considered high. Managing levels of water stress is crucial to ensuring that society’s needs for generating electricity, irrigating crops, and providing drinking water and sanitation can be met. Solutions include making use of wastewater, desalination technology and agricultural drainage water, as well as increasing efficiency of water use (SDG target 6.4). [Publication: Incorporating Environmental Flows into “Water Stress” Indicator 6.4.2] [UN-Water Report Webpage] [UN-Water Press Release] [Webcast of FAO Launch] [FAO Web Page on SDG Indicator 6.4.2]

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