Definition - What does Water Stress mean?
Water stress is a term used to describe when demand for water is greater than the amount of water available at a certain period in time, and also when water is of poor quality and this restricts its usage. Water stress means deterioration in both the quantity of available water and the quality of available water due to factors affecting available water.
Safeopedia explains Water Stress
Examples of water stress that affect the quantity of available water include the overuse of groundwater sources or aquifers and dry rivers. Examples of quality affecting water stress include an excess of nutrients in a water source or eutrophication, which is often caused by runoff from the land and causes excessive plant growth, or pollution from inorganic or organic matter, which is hazardous to health, saline intrusion from salt-water etc..