Step 3

Measure, set & disclose freshwater targets

The first freshwater science-based targets focus on two key issues: water use, specifically withdrawals from surface water bodies and groundwater, and freshwater pollution resulting from nitrogen and phosphorus.

These pressures are the first to be addressed by freshwater science-based targets because of their relevance to the majority of companies (freshwater use), their significance in specific sectors and environmental issues (freshwater pollution, and are together two of the key pressures that are driving the loss of nature in ecosystems around the world.

“[SBTN has had] a tremendous change because our water ambition has a lot of legacy in it… it was always driven by reduction, metric efficiency, and regulation, not eutrophication.”

SBTN 2024 Pilot Company
Freshwater use and pollution are driving the loss of nature in ecosystems around the world.

How does acting on my Freshwater targets contribute to nature and biodiversity?

Many pressures from human activity affect the functioning of healthy freshwater systems. In terms of water quantity, the current version of the Step 3 tasks focuses on water withdrawals—the extraction of water from surface sources (rivers and lakes) and groundwater sources (aquifers).

Water withdrawals reduce water volumes in the environment and can decrease the capacity of the environment to both sustain plants and animals in the ecosystem and to meet human needs, including drinking water, hygiene, recreation, and transportation. Reductions in water flows or the resulting changes in the ecosystem may also affect the soil structure, the local climate, and even water quality by increasing the relative concentration of pollutants, among many other potential impacts.

Science-based targets for water quantity are calculated so that environmental flows are maintained in each basin; these are the minimum water flows required to sustain ecological processes and safeguard habitat and other requirements for the survival of species. Thresholds for groundwater can safeguard freshwater connectivity by averting groundwater depletion.

Other pressures on water quantity, such as the use of rainwater, disruptions in water systems from infrastructure (including dams), and the diversion of water volumes between basins are not covered by the current version of the methods.

In terms of water quality, nutrient pollution is the focus of the current version of Step 3 methods, specifically the loading of nitrogen and phosphorus.

Nitrogen and phosphorus, found naturally in water and soil, are essential for the growth of all living organisms, including aquatic life. However, in large concentrations, these nutrients result in fast and excessive growth of organisms such as algae and cyanobacteria. As these organisms eventually die, the decomposition of their biomass depletes the oxygen dissolved in water systems, leading to the asphyxiation of other aquatic life. This process, called eutrophication, may also release toxins into the environment (if produced by algae and cyanobacteria) and block the sunlight from other aquatic plants. Eutrophication may extend beyond freshwater systems to coastal areas as oxygen-depleted water flows down rivers and into the ocean.

Science-based targets for water quality are calculated so that nutrient concentrations in water systems remain below the threshold that leads to excessive growth of algae and cyanobacteria, avoiding the effects of eutrophication.

Other elements and activities that affect water quality are out of scope of the current methodology, including the loading of other pollutants (beyond nutrients) as well as activities that affect turbidity (e.g., sediment release) or change the water temperature (e.g., release of cooling water).

More information on why freshwater science-based targets are important and how they connect to related corporate water stewardship initiatives can be found in our ‘Corporate water stewardship and science-based targets for freshwater’ paper.

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Freshwater targets are basin-specific

All basins vary in terms of their local climate, topography, soil conditions, and local biodiversity, among many other factors. Humans exert varying degrees of pressure on each basin depending on factors such as population and economic activities, whether that is water withdrawals or nutrient pollutant loading. For this reason, Freshwater targets are basin-specific: they are defined as the difference between baseline and maximum allowable pressures at each basin.


Water withdrawals and water consumption: Withdrawals are a pressure indicator that describes the amount of water removed from the environment, from any source (e.g., surface or groundwater), for anthropogenic purposes; consumption is similar but describes net removals, once water returns are considered (e.g., from non-consumptive water uses).

Water availability: A state of nature indicator that describes the water flows (in rivers) and levels (in lakes and aquifers) potentially available to meet human and natural needs.

Environmental flows: An indicator used to describe the minimum amount of water flows necessary in the environment to sustain ecological processes and safeguard biodiversity habitats. It is used as the environmental threshold that helps determine the water quantity target’s ambition levels.

Nutrient loading to freshwater: A pressure indicator that describes the mass of nutrients (nitrogen and phosphorus) added to the environment from anthropogenic sources.

Freshwater nutrient levels: A state of nature indicator that describes the existing concentration of nutrients (nitrogen and phosphorus) in freshwater systems.

Eutrophication: The process of accelerated biomass growth in freshwater systems due to excess nutrient availability and the consequent oxygen depletion in the system. It is used as the environmental threshold that helps determine the water quality target’s ambition levels.

Go to Step 3 Freshwater: Quantity and Quality