Bulletin No. 46 - Earthen Dams

According to the last census, 92 1/2 per cent of the Utah farms are irrigated. The advancement of agriculture in this State mainly depends upon the water, the available supply of which, in many of the older settled localities of the State, is already wholly utilized during the irrigation period. The future reclamation of new lands in such localities must, therefore, wait on the development of new sources of supply from storage reservoirs, sub-surface supplies, or from a more economical use of the summer flow of the available streams. From estimates and measurements made by the hydrographers. of the United States Geological Survey, the minimum flow of the Utah streams during the season of maturing crops is only about one-seventh of the average annual flow. If, therefore, it were possible by storage reservoirs to maintain the flow of the streams so that their summer discharge would be equal to the average for the year, the area irrigated might be increased seven-fold