The paper reviews the cost of different water supply and water treatment options around the world. The cost of supplying ground water is found to be proportional to the lift. The relationship between cost and volume of water treated by specific treatment options is assessed. Vehicular transportation of water is found to be very costly compared to wastewater treatment and compared to conventional water treatment and supply. Efforts have been made to differentiate the cost of water with respect to its application in various sectors. The capital cost of infrastructure required to extract, treat, supply, and reclaim water is also studied. Finally, the effects of precipitation, geographic aspects, population, financial, regulatory laws, and social attributes of a specific region are considered as they affect the cost of water. Global use of water in agriculture and the costs of agricultural irrigation are studied. Pressurized irrigation systems are costlier compared to flood or surface irrigation systems. © 2013 Desalination Publications.