Water degradation

Water degradation is the progressive deterioration of the quality, quantity and functionality of water resources such as rivers, aquifers, wetlands and coastal areas. It can be caused by natural factors (such as prolonged droughts) but, in most cases, it is a direct result of human activities: industrial pollution, over-abstraction, deforestation, uncontrolled urbanisation and poor wastewater management.

Water degradation refers to a structural loss of the ecosystem services that water bodies provide: supply, climate regulation, aquifer recharge, biodiversity support and food production. This loss compromises environmental sustainability, human health and socio-economic development.

Types and dimensions of degradation

Water degradation can be classified by its main dimensions:

Chemical pollution

Caused by industrial, agricultural or domestic discharges. Excess nitrates, heavy metals or microplastics impair the potability of water and destroy aquatic biodiversity. Many river basins show levels of toxicity that are incompatible with basic water uses.

Biological pollution

Associated with untreated wastewater. The proliferation of pathogenic bacteria and organic matter causes waterborne diseases, eutrophication and loss of oxygen in receiving water bodies.

Over-abstraction

Withdrawing more water than is naturally recharged degrades surface and groundwater systems. This leads to aquifer collapse, land subsidence and salinisation in coastal areas, and is a key driver of water stress.

Hydromorphological alteration

The construction of dams, channelisation or changes in land use fragment aquatic ecosystems, alter the natural flow regime and reduce the ecological connectivity of rivers.

Structural causes

Water degradation is not an isolated phenomenon but a symptom of an unsustainable development model. Its underlying causes include:

• Lack of spatial and water planning.
• Intensive and unregulated land use.
• Externalisation of impacts by extractive sectors.
• Insufficient treatment and monitoring systems.
• Absence of effective water governance and institutional transparency.

Indicators to assess degradation

Several metrics exist to identify and track the evolution of water degradation:

• Water quality indices (COD, BOD, nitrates, conductivity, coliforms).
• Index of biotic integrity (based on macroinvertebrate biodiversity).
• Changes in aquifer recharge and in ecological flow.
• Rate of loss of wetlands or natural water bodies.

This data should be collected systematically and transparently to guide public policy and enable citizen participation.

Ecosystem and social impacts

Water degradation generates cascading effects:

• Loss of endemic aquatic species.
• Decline in fisheries productivity.
• Higher costs for drinking water treatment.
• Territorial disputes over access to safe sources.
• Health vulnerability in rural or peri-urban communities.

In the long term, this degradation compromises the achievement of the Sustainable Development Goals, especially SDG 6 (clean water and sanitation), SDG 13 (climate action) and SDG 15 (life on land).

Restoration and resilience strategies

The most effective response to water degradation is ecosystem restoration, combined with adaptive management. Some key lines of action include:

• Rehabilitation of wetlands and riverbanks.
• Tertiary treatment and reuse of wastewater.
• Progressive elimination of persistent pollutants.
• Multi-stakeholder governance of river basins.
• Strict regulation of fertiliser use and industrial discharges.

Water degradation from an ESG perspective

From a corporate standpoint, operating in areas with degraded water bodies entails high operational, reputational and financial risk. For this reason, more and more companies carry out environmental audits, assess their water dependency through a water risk assessment and set impact metrics to reduce their water footprint on aquatic ecosystems.

Frameworks such as the Science Based Targets Network (SBTN) freshwater targets, CDP's water security disclosure and the GRI Standards (in particular GRI 303 on Water and Effluents) allow organisations to measure and disclose how they contribute, or not, to water degradation.

At Manglai we help companies measure their environmental footprint and prepare their sustainability reporting, including water-related impacts and risks. Discover how Manglai can help you.