In 1910 John Dethridge created a wheel that could measure the amount of water flowing past it in a channel. This Australian innovation made it possible to monitor the volume of water flowing from a river to an individual farm. It was an important innovation in the development of the irrigation districts along the rivers of the Murray Darling Basin during the first half of the 20th Century. When farmers settled along NSW rivers, the government gave them rights to extract river water for their crops. Each farmer could only take a specified amount. As irrigated farms grew in number and size it became apparent that water would be a limited resource that should be shared equitably.