Irrigation is practiced extensively, making water a major resource in drier regions.
Fuel resources are inadequate, despite some deposits of bituminous coal, anthracite, lignite, petroleum, and natural gas. Large deposits of sulfur, mercury, gypsum, nickel, copper, phosphates, potassium, lead, zinc, and uranium occur, but most deposits lie in folded and faulted areas surrounding the edges of the Meseta and are difficult to extract. Hydroelectric power is important, but costly dams are required to regulate the seasonal flow of most rivers.