Source: USDA news release
Irrigation water delivery organizations are entities such as irrigation districts and ditch companies that supply farmers, ranchers, and other users with water. These organizations draw water from several different sources. Water from Federal water projects and direct diversions from surface water bodies make up the majority of inflows to these organizations.
Yet there is substantial variation across organizations based on size. Large water delivery organizations, (which supply water to more than 10,000 acres) tend to contract water from Federal water storage facilities rather than draw from natural surface sources such as rivers.
However, small water delivery organizations (supporting less than 1,000 acres) draw a much higher proportion of their water inflows from surface sources. These differences reflect the historical development of irrigation organizations, with larger organizations developing in tandem with or as part of top-down approaches to provide water for irrigation, while small organizations developed from the ground up as small private ventures or community-led efforts.