IRRIGABLE LANDS OF THE VALLEY OF THE SEVIER. 145 
to create 30 or 40 square miles of lake surface, with an average depth of 
20 feet, upon that plateau alone The precipitation upon its surface would 
be more than sufficient to fill these lakes every year. A dam across the 
upper part of East Fork Canon would create a lake behind it which might 
have an area of 12 to 15 square miles. Numerous reservoirs could be 
created at small expense in Grass Valley, upon the Fish Lake Plateau, and 
upon the Sevier Plateau, and in those valleys which are drained by Salina 
Creek and its tributaries. The Sevier River itself can be cheaply dammed 
at several gorges and made to overflow swampy flats above—notably at 
the head of Marysvale Canon, and again just north of Van Buren’s ranch. 
Other things equal, it would be better, as well as cheaper, to build dams at 
higher levels, since the evaporation is much less there than in the valleys, 
and the natural facilities for creating lakes are also greater. 
In this way, I believe it to be practicable to reserve a store of water 
sufficient to irrigate every acre of ground in the Sevier Valley, which is 
by the nature of its soil and its situation suitable for irrigation. It may be 
noted, too, that the ‘tank system” thus suggested would not interfere 
with or take the place of the present system, but would be supplementary 
to it. ‘The streams would in June and early July run through the lakes 
and over the dams, yielding about as much water as they now yield in 
those months, and the reservoirs would not have to be drawn upon before 
the middle of July. 
A very interesting subject connected with the peculiar conditions of 
agriculture in the west is the origin and distribution of alkaline salts in the 
soil. In moist regions such occurrences are rare. They are peculiar to 
arid regions, and, in truth, very few arid regions fail to exhibit them. The 
cause in a general way is well known. The small amount of rain which 
falls during the wet season penetrates deeply into the earth, where it 
gradually takes up such soluble salts as it encounters there. During the 
dry season which follows, there is always going on an evaporation from 
the surface, however dry it may appear to the senses. It is a mistake to 
suppose that because the saline soil is as dry as ashes no evaporation is 
in progress. In many cases this may be true; but often in the most arid 
regions there are many localities where the water collects far below the 
1S) NTR, 
