Water is a product of excretion common to the kidneys, lungs, and skin in mammals, although it is excreted in different forms and quantities by each organ. 

• Kidneys:The kidneys excrete water as a component of urine, along with other waste products like urea and salts.

• Lungs:The lungs excrete water in the form of water vapour during exhalation, along with carbon dioxide.

• Skin: The skin excretes water through sweat, which also contains salts and other waste products.