In determining the volume of water flowing in the streams great accuracy has not been attained. For this purpose it would be necessary to make continuous daily, or even hourly, observations for a series of years on each stream, but by the methods described in the following chapters it will be seen that a fair approximation to a correct amount has been made. For the degree of accuracy reached much is due to the fact that many of the smaller streams are already used to their fullest capacity, and thus experience has solved the problem. Having determined from the operations of irrigation that one cubic foot per second of water will irrigate from 80 to 100 acres of land when the greatest economy is used, and having determined the volume of water or number of cubic feet per second flowing in the several streams of Utah by the most thorough methods available under the circumstances, it appears that within the territory, excluding a small portion in the southeastern corner where the survey has not yet been completed, the amount of land which it is possible to redeem by this method is about 2,262 square miles, or 1,447,920 acres. Of course this amount does not lie in a continuous body, but is scattered in small tracts along the water courses. For the purpose of exhibiting their situations a map of the territory has been prepared, and will be found accompanying this report, on which the several tracts of irrigable lands have been colored. A glance at this map will show how they are distributed. Excluding that small portion of the territory in the southeast corner not embraced in the map, Utah has an area of 80,000 square miles, of which 2,262 square miles are irrigable. That is, 2.8 per cent. of the lands under consideration can be cultivated by utilizing all the available streams during the irrigating season. In addition to the streams considered in this statement there are numerous small springs on the mountain sides scattered throughout the territory--springs which do not feed permanent streams; and if their waters were used for irrigation the extent of irrigable land would be slightly increased; to what exact amount cannot be stated, but the difference would be so small as not to materially affect the general statement, and doubtless these springs can be used in another way and to a better purpose, as will hereafter appear. This statement of the facts relating to the irrigable lands of Utah will serve to give a clearer conception of the extent and condition of the irrigable lands throughout the Arid Region. Such as can be redeemed are scattered along the water courses, and are in general the lowest lands of the several districts to which they belong. In some of the states and territories the percentage of irrigable land is less than in Utah, in others greater, and it is probable that the percentage in the entire region is somewhat greater than in the territory which we have considered.