Water Questions & Answers
Floods, droughts, glaciers:
Water Questions & Answers
Which states irrigated the most?
Agriculture is a big business in the United States, and a lot of water is used to produce our food. In 2005, farmers used water to irrigate about over 61,150,000 acres of land. That is about 95,550 square miles, which you can think of as a big, square plot of land about 309 miles on a side. And that is only the land that was irrigated; other land produced crops without the use of irrigation.
The majority of withdrawals (85 percent) and irrigated acres (74 percent) were in the 17 conterminous Western States. The 17 Western States are located in areas where average annual precipitation typically is less than 20 inches and is insufficient to support crops without supplemental water. Surface water was the primary source of water in the arid West and the Mountain States. California, Idaho, Colorado, and Montana combined accounted for 49 percent of the total irrigation withdrawals and 64 percent of surface-water irrigation withdrawals. Nearly 90 percent of the groundwater used for irrigation was withdrawn in 13 States, and each of these States withdrew more than 1,000 Mgal/d (1,120 thousand acre-feet per year) of groundwater for irrigation in 2005. Among these 13 States, groundwater was the primary source for irrigation in Nebraska, Arkansas, Texas, Kansas, Mississippi, and Missouri.
Total irrigation withdrawals in both Eastern and Western States were smaller in 2005 than in 2000, but because the West accounts for such a large majority of the total, changes in those States have a greater effect on the total. Groundwater withdrawals increased slightly in the East, and surface-water withdrawals declined in both the East and West. Total irrigated acres decreased in the West by 4 percent and increased in the East by 5 percent. In the West, acres irrigated by surface (flood) irrigation methods declined by 16 percent, and acres irrigated by sprinkler (spray) methods increased by 9 percent. Irrigated acres in the East increased for all type of systems; the largest percentage increase was in microirrigation systems.
Five States—California, Nebraska, Texas, Arkansas, and Idaho—accounted for 52 percent of total irrigated acreage. Nebraska, Texas, and California accounted for 41 percent of the irrigated acreage using sprinkler and microirrigation systems. California alone accounted for 65 percent of the irrigated acreage with microirrigation systems. Sprinkler and microirrigation systems combined were associated with more than 56 percent of total irrigated acreage.