Raw water refers to untreated, natural water sources, including rivers, streams, lakes, reservoirs, oceans, rainwater and groundwater used for ecosystems, drinking water, energy generation and food production. Raw water is central to the energy-water-food nexus through factors such as development density, deforestation, fertilizer and pesticide use. These factors impact raw water quality, creating the need to use more energy-intensive treatment technologies to bring water to potable levels. These factors also affect the health of ecosystems and the associated goods and services they provide.