Excerpts: It is the weakest link which measures the strength of a chain; so in the use of rivers in irrigation, it is not their flood volume, but the discharge at time of greatest need which measures their usefulness and value to farmers along their banks. A river which carries a torrent in December but is a bed of dry sand in July is of little value to irrigators if left as nature made it. There are hundreds of such streams in the West. They wind their lonesome courses through lands of unsurpassed fertility, where the climate is salubrious and healthful, and where only a perennial supply of moisture is needed to secure the growth of products of great diversity and value. On some the flood period comes a month too soon; on others months too late. The first objection applies to nearly all the rivers in the northern half of the irrigated region; the second to those in the southern half. The important function of reservoirs is to bring the total supply into agreement with farmers’ needs, in order that the water may be more completely utilized. The farther the natural flow falls short of accomplishing this the more important are reservoirs and the greater the necessity for their construction.
