A camel’s hump does not hold water at all – it actually stores fat. The camel uses it as nourishment when food is scarce. If a camel uses the fat inside the hump, the hump will become limp and droop down. With proper food and rest the hump will return to normal.
The hump is not used for water storage, but camels can go for long periods of time without water. They drink large amounts of water – up to 20 gallons at a time. This water is stored in the animal’s bloodstream.