The supply of water system refers to the infrastructure and processes involved in providing clean and safe water to residential, commercial, and industrial users. These may include surface water sources such as rivers, lakes, and reservoirs, as well as groundwater sources accessed through wells.

Raw water extracted from the sources usually contains impurities and contaminants that need to be removed to make it safe for consumption. Water treatment plants employ a combination of physical, chemical, and biological processes to purify the water.

Effective management of the water supply system is essential for ensuring public health, supporting economic activities, and protecting the environment. This often involves collaboration between government agencies, water utilities, regulators, and the public to address challenges such as water scarcity, pollution, and aging infrastructure.