The Dethridge wheel is used throughout Australia

Irrigation in Australia

Irrigation in Australia is a widespread practice to supplement low rainfall levels in Australia with water from other sources to assist in the production of crops or pasture. As the driest inhabited continent, irrigation is required in many areas for production of crops for domestic and export use...

 and in many other countries, including the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

 and in Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, to measure the flow of water delivered to farms

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

 for irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

.

The wheel consists of a drum on an axle, with eight v-shaped vanes fixed to the outside. It sits laterally across a channel and is turned by water flow. The revolving wheel measures flow from the irrigation supply channels into the farm channels, providing the basis upon which irrigation farmers are charged for water. Wheels generally last for 15 to 20 years, and the axle is replaced every 5 years.

The wheel was invented by John Dethridge in Australia in 1910. Dethridge was then commissioner of the Victorian State Rivers and Water Supply Commission.