Water Production

Water is a commodity essential to human survival, found throughout the wastelands.

Background
Following the Great War, some water sources have become irradiated and require purification so not to cause illness or death. The scarcity of water and its necessity has resulted in novel initiatives and inventions focused on the purification and distribution of the commodity. This dynamic has also served as the impetus for several post-War businesses, caravan routes, and formed the basis of entire economies.

Fallout
It is the underlying theme of the Hub, which is the primary source of drinkable water for most cities, having access to a water tower and able to pump large quantities of it for sale. The tower was the cause of much strife in the city, as different merchant companies vied for control of it. Settlements have sources of water of their own wells, but usually only cover the most basic of needs.

Fallout 2
Water availability and distribution are much less emphasized, except for Modoc, where a catastrophic drought has occurred, putting on the brink of collapse, forcing it to forge an alliance with the Slags of Ghost Farm.

Fallout 3
Water availability is the underlying theme of the game, with the overarching goal of helping Rivet City's scientists in activating Project Purity to provide clean water for the entire region. Pinkerton mocks the Rivet City science team for being unable to "purify a little water." In Megaton, the robot butler that comes with player housing has a condensation unit that produces purified water. Tenpenny Tower has sinks that dispense pure, rad-free water.

Fallout: New Vegas
Water is so precious that it acts as a catalyst for war. The Hoover Dam not only produces power but also provides clean, drinkable water in nearly limitless quantities via Lake Mead and the Colorado River. The First Battle of Hoover Dam was fought between Caesar's Legion and New California Republic in 2277, resulting in a Legion defeat and the near complete destruction of nearby Boulder City. The two faced off once more during the Second Battle of Hoover Dam, attempting to wrest control of the precious resource from one another four years later

Aside from the prominent water source that is the Hoover Dam, small communities also worked diligently to devise ways to prepare, purify, and store water in order to survive the arid climate of the vast Mojave. Members of the Boomers have a water filtration system set up within their settlement at Nellis Air Force Base. Scarcity of potable water is a significant issue not just for human and animal consumption but also when considering agriculture. In the central New Vegas outskirts, the New California Republic has established sharecropper farms to help feed citizens and troops in the region. Due to the Office of Science and Industry miscalculating and underproviding the quantity of water the sharecroppers need by 20%, they express concern about being unable to meet crop quotas.

The finite nature of the resource causes smaller scale conflicts among factions and groups in the wasteland. The Freeside water pump is owned by the King, guarded by his underling Tapper. Attempting to drink out of the pump without paying will cause the Kings to become hostile.

In Westside, citizens have been more successful in establishing sustainable agriculture, but are limited by their lack of a reliable source of clean water. With the help of engineer Tom Anderson and the Followers of the Apocalypse, Westside citizens have implemented a small scale irrigation system, allowing the settlement to reach a stable level of self-sufficiency.

There are also naturally pure water found several places that the Courier can utilize, including water at Goodsprings source, the south cistern, the sinks inside both the Crimson Caravan Company's caravaneer and guard barracks. There is also a naturally occurring source at Forlorn Hope Spring, the location and namesake of the New California Republic's Camp Forlorn Hope.

Purifying or purchasing one's own water can be accomplished in a variety of ways while out in the Mojave. The Courier can collect cactus water, which is purified water from desert plants. Purified water can also be purchased from several merchants, including Tapper, Lupe at the Grub n' Gulp rest stop, and William Farber, the NCR chef in Camp McCarran. The player character can also fill most empty bottles at the Sink at Big MT to create purified water.

Fallout 4
In Fallout 4, communities purify their own water by way of large machines placed into water. In Diamond City, Sheng Kawolski runs a water purification business and Mayor McDonough touts running water as one of the amenities of Diamond City residency. Piper Wright also mentions being thankful for the city's running water in the Publick Occurrences article titled "View from the Vault." Water pumps and purifiers can be built within settlements, increasing water production. Cooking stations can be used to turn dirty water into purified water. Purified water can also be bought from merchants and found in first aid kits.

Appearances
Water production in its various forms appears in all Fallout games.