---
url: https://www.eurocovers.eu/glossary/water-stress
term: Water stress
definition: A measure of demand on available water resources relative to supply. Determines the economic case for evaporation suppression and reservoir capacity retention.
updated: 2026-05-25
---

# Water stress

A measure of demand on available water resources relative to supply. Determines the economic case for evaporation suppression and reservoir capacity retention.

**Water stress** is the ratio of water withdrawal to renewable supply in a given region. EU
classification ranges from low (most of northern Europe) to extreme (southern Spain, parts of
Italy and Greece). Water-stressed regions present the strongest economic case for floating
covers: every cubic metre saved through evaporation suppression directly reduces operating cost
and supports regulatory compliance under the EU Water Framework Directive.