The distribution of water on the Earth's surface is extremely uneven. Only 3% of water on the surface accounts for freshwater; the remaining 97% is salt water and resides in the ocean. Of freshwater, 69% resides in glaciers, 30% underground, and less than 1% is located in lakes, rivers, and swamps.

Water and water-related ecosystems play a fundamental role in the health of the environment, in providing services to people and communities, in combating the impacts of climate change and in all economic activities. Working on the environmental aspects of monitoring, managing and protecting water resources and freshwater ecosystems has been an integral part of UNEP’s mandate since its inception. Against this background and in the framework of the Sustainable Development Goals (SDGs), UNEP has been entrusted with the co-custodianship of three water indicators (SDG 6.3.2, 6.5.1 and 6.6.1) related to the following freshwater targets:

• SDG 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally;
• SDG 6.5: By 2030, implement integrated water resources management at all levels, including through transboundary cooperation as appropriate;
• SDG 6.6: By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes. In addition, UNEP’s freshwater activities contribute to reaching and monitoring several other water-related SDG targets.

Story map can be accessed here

Readily accessible freshwater – which is found in rivers, lakes, wetlands and aquifers – accounts for less than one per cent of the world’s water supply and so it is imperative that the state of this vital resource is monitored. As the global human population grows, so too do the demands for water. At the same time, human activity and climate change are disrupting natural water cycles, putting freshwater ecosystems under pressure. Poor water management, pollution, infrastructure development and resource extraction further exacerbate the negative impacts on our freshwater systems. Therefore, it is important to provide the world community with sound data on the state of freshwater to support scientific assessments and decision-making. The table below provides relevant web links to online portals and tools related to water and SDG6 in general, water quality, Integrated Water Resources Management (IWRM) and water related ecosystems:

Water quality is naturally influenced by the climatological and geochemical location of the water body through temperature, rainfall, leaching, and run off of elements from the Earth’s crust. However, most surface water bodies around the world are also affected by impacts from human activities, particularly the discharge of waste products (including sewage and plastics) or addition of sediments, salts and minerals with run-off from agriculture and urban settlements. Recognizing that water is essential for human health, well-being and livelihoods, ecosystem functioning and services, and the survival of all living species, there is an urgent need to better understand the current drivers and pressures affecting the quality of this vital resource and drivers of its degradation.

The Global Environment Monitoring System for freshwater (GEMS/Water) provides the world community with sound data on freshwater quality to support scientific assessments and decision-making on the subject. Surface and ground water quality monitoring data collected from the global GEMS/Water monitoring network is shared through the GEMStat information system (dashboard below). 

The GEMStat Water Quality Dashboard can be accessed here

Another strong player working on the issue of water quality is the World Water Quality Alliance (WWQA).The WWQA is a voluntary global expert consortium of more than 50 partners from public, private sector, civil society, and UN-Water convened by UNEP in direct response to the UNEA resolution 3/10 on addressing water pollution to protect and restore water-related ecosystems.

Groundwater, given its nature as an underground and hidden freshwater resource, is nevertheless impacted by a myriad of pressures including pollution loads from human activities such as, untreated wastewater and agriculture, leaching from landfills, and salinization of coastal aquifers as a result of sea level rise. The WWQA has a dedicated workstream on groundwater, the Friends of Groundwater (FoG). The main objective of this workstream is to improve the global knowledge base on groundwater quality through the development of a set of recommendations and guidelines to assist regional groundwater quality assessments. Naturally occurring arsenic in groundwater affects millions of people worldwide. The ingestion of arsenic, for example through water or food, can lead to disorders of the skin and vascular and nervous systems as well as cancer. This global prediction map of groundwater arsenic exceeding the WHO guideline for drinking water of 10 μg/L was created using machine learning modelling with climate, soil and topography parameters as predictors and more than 50,000 measured groundwater arsenic concentrations. This map is not a replacement for the independent assessment and monitoring of arsenic in groundwater sources, but should be used to raise awareness, identify areas for safe wells, and help prioritize testing.

Map credit: Global prediction of groundwater arsenic (Podgorski and Berg, 2020). Modelled probability of arsenic concentration in groundwater exceeding the WHO guideline of 10 mg/litre for the entire globe.

The FoG has produced a perspective paper: Assessing Groundwater Quality: A Global Perspective

UNEP plays a central role in supporting countries’ work to build their capacity to deliver on their environmental goals and commitments under international agreements. The UNEP capacity development portfolio is steadily growing and in terms of freshwater it provides substantial input and leadership as part of the UN-Water SDG6 Accelerator Framework Capacity Development Initiative.

UNEP’s GEMS/Water programme collects and provides access to quality-assured data on the quality state of the world’s freshwater resources, supports the underlying monitoring, and assists Member States in technical and institutional capacity building to that effect. The Capacity Development Consortium Workstream of the WWQA is a welcome addition to the work of the GEMS/Water programme and aims to provide a larger range of capacity building activities to Member States.

• Working document - Information on implementation of resolution 3/10 on addressing water pollution to protect and restore water-related ecosystems - UNEA 5.1 - February 2021
• Information Document - Progress in the implementation of resolution 3/10 on addressing water pollution to protect and restore water-related ecosystems - UNEA 5.1 - February 2021
• ASSESSING GROUNDWATER QUALITY: A GLOBAL PERSPECTIVE (Importance, methods and potential data sources) - World Water Quality Alliance (WWQA), 2020
• WORLD WATER QUALITY ASSESSMENT: First Global Display of a Water Quality Baseline - World Water Quality Alliance (WWQA), 2020
• Monitoring Plastics in Rivers and Lakes: Guidelines for the Harmonization of Methodologies - United Nations Environment Programme (UNEP), 2020
• UNEA Resolution 3/10 - Addressing water pollution to protect and restore water-related ecosystems - 2017
• The Snapshot Report of the World’s Water Quality - United Nations Environment Programme (UNEP), 2016
• Towards a Worldwide Assessment of Freshwater Quality - UN - Water, 2016