Brent Zimmer Jr., age 14, of Galveston, Texas, for his question:
WHEN WAS IRRIGATION FIRST USED?
Irrigation is the watering of plants by artificial means. Without irrigation there could be no farming in dry regions. Very early in history, man learned how to move water. The ancient Egyptians, for example, practiced irrigation more than 4,000 years ago.
The Egyptians at first carried water from the Nile River to their fields in jars. Later they learned to divert the water to the land through simple dams and canals. The early irrigation systems depended on the yearly flooding of the Nile.
Irrigation was carried on by town dwelling Indians of New Mexico and Arizona long before the white man came to America. The care of the irrigation ditches was a community responsibility.
The Spaniards who came to America knew something of the irrigation system that the Moors had established in Spain, and they taught the Indians to build dams and reservoirs.
In 1847, the Mormons established one of the first irrigation systems for white farmers in the West. When pioneer gold seekers were mining California gold by washing it from the stream beds, many ditches were dug. Some of these ditches afterward proved valuable as irrigation ditches.
Until the late 1800s, there was little land under irrigation in the United States. The first federal irrigation project was started in 1868 to irrigate land on the Mojave Indian Reservation in Arizona.
In 1894, Congress adopted the Carey Act, which granted land to states and territories that would build irrigation systems. Few states or territories took advantage of this act, however, and the federal Reclamation Act of 1902 gave the United States Department of the Interior the power to construct irrigation systems with funds obtained from the sale of public lands in the states mentioned in the Carey Act.
Although irrigation had been practiced in simple ways for thousands of years by people in many parts of the world, it has been only since the late 1800s that man has applied scientific knowledge to watering dry waste places so that they became fertile land.
Much water for irrigation is pumped from wells which tap the great supplies of ground water that lie beneath the soil. About one third of the irrigated land in the United States receives its water from underground sources. The energy for pumping underground water is supplied by windmills, gasoline engines and electric motors.
Most of the water distributed to farm lands in the United States and Canada is run on to the farms through open ditches. The main ditch, or canal, takes water from the source of supply.
Smaller ditches, called laterals, leave the main ditch at regular places and take the water to the fields. Special gates, called head gates, regulate the flow of water into the laterals.
Irrigation reduces crop failures from drought and other causes and makes a higher standared of living possible in the particular region.