Elephants need water - lots of it. Depending on their size, they must drink 100 to 200 litres at least every two to three days to avoid potentially severe dehydration. In hot weather, an elephant can lose as much as 7.5% of its body mass daily due to dehydration. So, water availability, particularly in dry seasons and drought, is critical to elephant survival. Water dictates where elephants roam, limiting their foraging range to areas close to rivers, lakes, pans, and other wetlands. For example, elephant herds with calves stray no further than 10 kilometres from water. If left to their own devices and given enough space, elephants migrate in response to rainfall variability, prompting predictable seasonal land-use patterns. For instance, in dry times, elephants will gather around perennial rivers and other permanent water sources. At the same time, in the wetter months, herds will disperse widely to take advantage of seasonal streams and ephemeral pans. Such natural ebbs and flows allow riparian vegetation to recover from the intense feeding pressure of elephants and other browsers. However, human-created watering points disrupted this cycle in one of Africa's foremost conservation areas, Kruger National Park. This practice of providing access to permanent artificial water sources began in the 1930s and accelerated dramatically in the 1960s and 70s. Over this time, more than 300 boreholes were drilled, and 50 dams were constructed in Kruger. The motivation was to improve wildlife numbers, and initially, it was successful. But there were unintended consequences - the constant availability of water interfered with the natural movement patterns of elephants, resulting in unsustainable damage to vegetation, which eventually led to the culling of elephant populations - which continued until the ideas behind IFAW's Room to Roam initiative began to take hold. Conservationists now think of elephant conservation in a new way.