"It is water. A substance composed of two atoms of hydrogen–"
"It's not water. It's blood and it's sweat. It's the result of a ninety years of combined effort."
Water (H2O) was a chemical substance which was often found in a liquid state at temperatures between 273 and 373 Kelvin, its melting and boiling points, respectively. At standard temperature and pressure, water was found in its liquid state. Water was crucial to the existence of life on Earth and to a certain extent to that of most other carbon-based lifeforms. It had some unique properties, such as an unusually high boiling point of 100° C and high adhesion and cohesion properties because of its polar nature and the existence of hydrogen bonding. Water's other states are solid, in the form of ice or snow and gaseous in the form of water vapor.
The microbrain referred to Humans as "Ugly giant bags of mostly water!" a description Lieutenant commander Data considered accurate as Humans were comprised of over 90% water and were surrounded by a flexible container. (TNG: "Home Soil")
Kataan was experiencing a constant drought towards the end of the planet's lifetime as its sun was rapidly approaching a nova. Water on the planet had to be rationed and it was considered to construct atmospheric condensers that could reclaim evaporating water from the air. (TNG: "The Inner Light")
The pre-industrial society of Barkon IV believed that water was one of the four basic elements of the universe, along with fire, sky and rock. Water was sometimes difficult to find in matter, but it was believed that all objects contained water. (TNG: "Thine Own Self")
When Doctor Julian Bashir arrived at the Bajoran village he received a medical emergency call from, he scanned the air, the ground water, and the soil but was not able to find any pollutants. (DS9: "The Storyteller")
In some regions of the Delta Quadrant, water was scarce and a valued commodity, traded amongst species such as the Kazon and Talaxians. In 2371, Captain Kathryn Janeway used water to bribe Kazon maje Jabin for information concerning the Ocampa. Later, when offered a bath by Tuvok, Neelix delightfully accepted, but was astounded by such an abundance of water that it could be used for the purpose of cleaning in such a manner. (VOY: "Caretaker")
A proper amount of water was important to the survival of plants, but too much water could be harmful to certain plants. When Julian Bashir tried to help Miles O'Brien care for Keiko's Idran hybrids, he gave them water when he saw that they were "as dry as a bone," unaware that too much water would rot their roots. (DS9: "The Assignment")
In gravitically unstable regions of space (such as the gravitational event horizon of a collapsing planet or star), water can form into long chains of polywater. (TOS: "The Naked Time"; TNG: "The Naked Now")
Aquatic lifeform types
Sentient aquatic species
- See: Drinking water
Bodies of water
- See: Bodies of water
Art about water
- Fresh water
- Great Material Continuum
- Ground water
- Heavy water
- Hoobishan Baths
- Qui'al Dam
- Water mass