In still other regions the rainfall is abundant, and the land low-lying. Large areas are always covered with water. Such lands are called swamps or bogs, and when drained, they become the richest of agricultural lands. Irrigation, storage and drainage are the three methods employed to make waste lands valuable and useful. The land is saved or reclaimed, so all these methods of balancing and distributing the water supply are called reclamation. In general it may be said that irrigation is more generally needed in the West, storage of flood waters in the central and eastern states, and drainage in the South. By thus distributing the rainfall, hundreds of millions of acres have been or may be reclaimed, and large regions, formerly unfit to inhabit, have been turned into profitable farms. Three-fourths of one per cent. of our total rainfall, or two per cent. of all that falls in the West, is used for irrigating 13,000,000 acres. There are several methods of irrigation which are adapted to different regions and different crops. The rice fields of South Carolina, Georgia, Louisiana and Texas are irrigated by allowing the land to remain continually flooded to a depth of several inches. When the irrigation season is over the levees are opened, and the water runs off rapidly, and the crop is soon ready to be harvested. Tidal rivers are used to supply water in most cases, but in Texas many flowing wells are employed for irrigation. In Florida, where irrigation is used largely for intensive farming, various means are employed, some of which are also used in the western and southwestern states. Mechanical pumps, operated by turbine wheels, pump the water from the rivers if a lift be required. Sometimes the water is pumped direct to the fields in iron pipes and applied by means of hydrants and hose, as in a city water system. Overhead pipe lines are now recognized as the most perfect and satisfactory form of artificial watering. Two-inch pipes are run over frames several feet in height. These are arranged in parallel lines all over the fields about forty feet apart. At intervals of forty feet, a small iron pipe, ending with a fine spraying attachment, extends upward. The water is turned on in the evening and comes out of the sprayer in a fine mist and falls upon the plants like a gentle rain. By another form of irrigation, the fields are divided at regular intervals by wide wooden troughs from which water is directed between the rows of plants. Main canals leading from the streams and intersected by short canals extend in all directions through the fields and orchards, and are distributed in various ways. This system is in general use throughout the arid portions of the West. The methods are said to be the most scientific and varied in southern California.