Those unacquainted with the industrial institutions of the far west, involving the use of lands and waters, may without careful thought suppose that the long recognized principles of the common law are sufficient to prevent the severance of land and water rights; but other practices are obtaining which have, or eventually will have, all the force of common law, because the necessities of the country require the change, and these practices are obtaining the color of right from state and territorial legislation, and to some extent by national legislation. In all that country the natural channels of the streams cannot be made to govern water rights without great injury to its agricultural and mining industries. For the great purposes of irrigation and hydraulic mining the water has no value in its natural channel. In general the water cannot be used for irrigation on the lands immediately contiguous to the streams--_i. e._, the flood plains or bottom valleys--for reasons more fully explained in a subsequent chapter. The waters must be taken to a greater or less extent on the bench lands to be used in irrigation. All the waters of all the arid lands will eventually be taken from their natural channels, and they can be utilized only to the extent to which they are thus removed, and water rights must of necessity be severed from the natural channels. There is another important factor to be considered. The water when used in irrigation is absorbed by the soil and reëvaporated to the heavens. It cannot be taken from its natural channel, used, and returned. Again, the water cannot in general be properly utilized in irrigation by requiring it to be taken from its natural channel within the limits ordinarily included in a single ownership. In order to conduct the water on the higher bench lands where it is to be used in irrigation, it is necessary to go up the stream until a level is reached from which the waters will flow to the lands to be redeemed. The exceptions to this are so small that the statement scarcely needs qualification. Thus, to use the water it must be diverted from its natural course often miles or scores of miles from where it is to be used.