IRRIGATION BY SMALL STREAMS.

Through the remainder of the drainage basin of Great Salt Lake there are no large bodies of farming land. At wide intervals are small tracts, dependent on springs and small creeks, and the available land is in nearly every case greatly in excess of the available water. A few exceptional spots are cultivated without irrigation, but so far as they have been discovered they are so situated as to be moistened from beneath. No crops have been raised on dry bench lands.

The principal facts are gathered in the following table:

Localities.No. of distinct tracts.Acres in cultivation in 1877. Acres cultivable.Cultivable acres not included in existing surveys.Remarks.
Cedar Fort 1 800 1,000 — With aid of reservoirs.
Fairfield 1 800 900 —
Vernon Creek 1 900 1,200 — With aid of reservoirs.
Saint Johns 1 700 700 —
East Cañon Creek, Rush Valley 1 500 900 —
Stockton 1 200 500 —
Skull Valley 111,000 2,500 (?)With aid of reservoirs; visited in part only.
Government Creek 1 300 300 — Not visited.
Willow Spring, township 10 south, range 17 west 1 250 250 — Do.
Redding Spring 1 20 50 —
Dodoquibe Spring 1 — 50 — Not visited.
Deep Creek, township 9 south, range 19 west 1 500 1,000 — With aid of reservoirs.
Pilot Peak 1 — 200 200Not visited.
Grouse Valley 6 500 1,500 — With aid of reservoirs.
Owl Spring 1 — 10 10
Rosebud Creek 1 150 400 — With aid of reservoirs.
Muddy Creek, township 10 north, range 15 west 1 300 300 300
Park Valley 6 700 2,300 — With aid of reservoirs.
Widow Spring 1 — 20 20Not visited.
Indian Creek, township 13 north, range 12 west 1 — 100 100With aid of reservoirs.
East base Clear Creek Mountains 6 5 150 100 Do.
Cazure Creek 1 — 200 200Not visited.
Clear Creek, township 15 north, range 12 west 1 80 200 200
Junction Creek 1 — 500 500Not visited.
Goose Creek 2 — 200 200 Do.
Pilot Spring 1 — 15 —
Deseret Creek (or Deep Creek) 1 300 3,000 — With aid of reservoirs.
Crystal Springs, township 14 north, range 7 west 1 60 100 100 Do.
Antelope Spring, township 9 north, range 6 west 1 30 30 30Not visited.
Hanzel Spring 1 15 15 15
Promontory, east base 1 300 600 600The greater part is not irrigated.
Blue Creek 1 — 1,500 —
Brackish Springs near Blue Creek 1 200 1,000 —
Antelope Island 1 — 50 50Not visited.
Total 608,61021,7401,625
Total in square miles — 13.5 33.9 2.5

Nineteen tracts have not yet been surveyed by the land office.

The total area of the district is 13,370 square miles, of which one-tenth of one per cent. is cultivated, and one-fourth of one per cent. may be cultivated.

The contrast between the districts east and west of Great Salt Lake illustrates the combination of physical conditions essential to agriculture in our arid territories. An atmosphere endowed with but a small share of moisture precipitates freely only when it is reduced to a low temperature. Agriculture is dependent on the precipitation of moisture, but cannot endure the associated cold climate. It can flourish only where mountain masses turn over the aqueous product of their cold climates to low valleys endowed with genial climates. The Wasatch and Uinta crests stand from 6,000 to 9,000 feet higher than the valleys bordering Great Salt Lake. Their climate has a temperature from 20° to 30° lower. The snows that accumulate upon them in winter are not melted by the first warmth of spring, but yield slowly to the advancing sun, and all through the season of growing crops feed the streams that water the valleys. The Bear, the Weber, and the Jordan carry the moisture of the mountains to the warmth of the valleys, and fertility is the result.

To the north and west of the lake there are many mountains, but they are too low and small to store up snow banks until the time of need. Their streams are spent before the summer comes; and only a few springs are perennial. The result is a general desert, dotted by a few oases.

CHAPTER VIII.
IRRIGABLE LANDS OF THE VALLEY OF THE SEVIER RIVER.

By Captain C. E. Dutton.

As an agricultural region, the valley of the Sevier River and of its tributaries is one of the most important in Utah. The amount of arable land which may be reached by the waters of the stream is very much larger than the stream can water advantageously, and the time is probably not far distant when all the water that can be obtained will be utilized in producing cereals, and there is probably no other region in Utah where the various problems relating to the most economic use of water will be solved so speedily. It is, therefore, a region of unusual interest, regarded in the light of the new industrial problems which the irrigation of these western lands is now bringing forward. Fortunately, there is a smaller prospect of difficulty and obstruction in the settlement of the legal controversies which must inevitably arise elsewhere out of disputes about water rights than will be encountered in other regions, for the Mormon Church is an institution which quietly, yet resistlessly, assumes the power to settle such disputes, and the Mormon people in these outlying settlements yield to its assumptions an unhesitating obedience. Whatever the church deems best for the general welfare of its dependencies it dictates, and what it dictates is invariably done with promptitude, and none have yet been found to resist. This communal arrangement has been attended with great success so far as the development of the water resources are concerned, and the system of management has ordinarily been so conducted that the general welfare has been immensely benefited; and if individuals have suffered, it has not been made manifest by any apparent symptoms of general discontent or of individual resistance. The system is by no means perfect as yet, but its imperfections may be found in details which produce no present serious inconvenience, and they will no doubt be remedied as rapidly as they attain the magnitude of great evils.

The Sevier River has its course along the southeastern border of the Great Basin of the west, and its upper streams head in the lofty divide which separates the drainage system of the Colorado River on the south and east from the drainage system of the Great Basin on the north and west. The general course of the upper portion of the stream is from south to north, though its tributaries flow in many directions. The lower portion of the stream, within 60 miles of its end, suddenly breaks through one of the Basin Ranges on the west—the Pavant—and then turns southwestward and empties into Sevier Lake, one of the salinas of the Great Basin.

The main valley of the Sevier River has a N. S. trend, and begins on the divide referred to, about 270 miles almost due south of Great Salt Lake, and continues northward a distance of about 170 miles. There are three principal forks of this stream. The lowest fork is at Gunnison, 140 miles south of Salt Lake City, and called the San Pete, which waters a fine valley about 45 miles in length, and which is at present the most important agricultural district in Utah. About 80 miles farther up the stream, at Circle Valley, the river divides into two very nearly equal branches; one coming from the south, the other breaking through a great plateau on the east. These are called, respectively, the South and East Fork of the Sevier. The South Fork has its principal fountains far up on the surface of a great plateau—the Panguitch Plateau—whose broad expanse it drains by three considerable streams, which finally unite in the valley at the foot of its eastern slope.

The East Fork of the Sevier receives the waters of a beautiful valley lying to the eastward of and parallel to the main valley of the Sevier, and separated from it by a lofty plateau 90 miles in length from north to south, and from 10 to 20 miles in breadth, called the Sevier Plateau. Through this great barrier the stream has cut a wide gorge 4,000 feet in depth and 10 miles long, called East Fork Cañon, and right at its lower end it joins the South Fork of the Sevier.

The physical geography of the region drained by the waters of the river is highly interesting, and has an important relation to the subject. The area in question consists of a series of tabular blocks, of vast proportions, cut out of the general platform of the country by great faults, and lifted above it from 2,000 to nearly 6,000 feet, so that the absolute altitudes (above sea level) of the tables range from 9,000 to 11,500 feet. Where the valleys are lowest the tables are highest, and vice versa. The valleys or lowlands stand from 5,000 to 7,500 feet above the sea. The plateaus have areas ranging from 400 to 1,800 square miles, and collectively with the included lowlands within the drainage system of the Sevier have an area of about 5,400 square miles. The tables front the valleys with barriers which are more continuous and which more closely resemble long lines of cliffs than the mountain chains and sierras of other portions of the Rocky Mountain Region, and there are stretches of unbroken walls, crowned with vast precipices, 10, 20, and even 40 miles in length, which look down from snowy altitudes upon the broad and almost torrid expanses below. If the palisades of the Hudson had ten times their present altitude and five or six times their present length, and if they had been battered, notched, and crumbled by an unequal erosion, they would offer much the same appearance as that presented by the wall of the Sevier Plateau which fronts the main valley of the Sevier. If they were from six to eight times multiplied, and extended from Hoboken to West Point, and were similarly shattered, they would present the appearance of the eastern wall of Grass Valley. If they were eight to ten times multiplied, and imagined to extend around three-fourths of the periphery of an area 40 miles by 20, and but little damaged by erosion, they would represent the solemn battlements of the Aquarius Plateau. These great plateaus are masses of volcanic rock overlying sedimentaries, the latter so deeply buried that they are seldom seen even in the deepest chasms, while superposed floods of volcanic outflows are shown in sections, reaching sometimes a thickness of 5,000 feet. The dark colors of these rocks give a somber aspect to the scenery, and the gloomy fronts of the towering precipices are rendered peculiarly grand and imposing.

The prevailing winds of this region are from the west, northwest, and southwest, and are a portion of the more general movement of the atmospheric ocean which moves bodily from the Pacific to the heart of the continent. In crossing the Sierra Nevada a large portion of its moisture is wrung from the air, which blows hot and arid across the Great Basin. Notwithstanding the aridity of the basin area, the air gains about as much moisture as it loses in crossing it, until it strikes the great barriers on the east side of the basin—the Wasatch and the chain of high plateaus which are mapped as its southerly continuation. Here the winds are projected by the bold fronts several thousands of feet upward. The consequent cooling and rarefaction condense from them an amount of moisture which, relatively to that arid country, may be called large, though far less than that of more favored regions. In the valleys the rainfall is exceedingly small; almost the whole of the precipitation is in the high altitudes. It is no uncommon thing to see the heavy masses of the cumulus clouds enveloping the summits of all the plateaus while the valleys lie under a sky but little obscured. The plateaus, then, are the reservoirs where the waters accumulate, and from which they descend in many rivulets and rills, while around their bases are copious springs fed by the waters which fall above. The rainfall in the valleys is very small, as compared with that upon the plateaus, and it is also highly variable. No record has been kept of the precipitation within the drainage system of the Sevier, and the nearest point where such a record has been kept is at Fort Cameron, near Beaver, at the western base of the Tushar Mountains. These observations cover but a brief period, and no doubt represent a much larger precipitation than that which occurs in the valleys and plains generally, because the situation of the point of observation is just at the base of the loftiest range in southern Utah, where the air currents from the west first strike it. Moreover, these observations are not yet published, and are not at present available. In the narrow valleys between closely approximated and lofty mountain walls, like the valley of the Sevier at Marysvale, the rainfall is greater than where the valley is wider, with lower walls, as at Panguitch, Richfield, and Gunnison. An estimate of the amount would be very hazardous; but, judging from what is known of similar localities, the amount in the wider valleys may be as low as 7 or 8 inches, or as high as 10 or 11. In the narrower and deeper valleys it may be between 10 and 12 inches. Upon the plateaus it may be as large as 30 to 35 inches. The principal fall is in the winter and spring months, from the middle of November to the first of June; and in this period at least seven-eighths of the precipitation must be accomplished in the valleys and three-fourths upon the plateaus. There is, however, a large amount of variation in the distribution of the monthly falls from year to year. No two consecutive years correspond in this respect. In 1876 a heavy storm, with great rainfall and snow, occurred in the month of October, but in 1875 and 1877 no such storm occurred. In 1875 many drenching showers occurred in the months of July and August, but none occurred at the same months of 1877. In general, however, no summer rainfall has ever been known of such extent as to dispense with the necessity of irrigation, or even to materially reduce the necessary amount. Great variability in the distribution of the fall over different months of the year is one of the characteristics of the climate. But whatever the distribution, it is never such as to affect this one conspicuous feature—that the season in which crops must have their chief growth and reach their maturity is the dry season.

Connected with the irrigation of the Sevier Valley is a limiting condition, which rarely has to be considered in connection with the lands watered by the Bear and Weber Rivers, and which does not enter at all into the lands lying about Great Salt Lake. It is the dependence of climate upon altitude. There are lands along the upper portions of the forks of the Sevier which can be irrigated easily enough, but which are not cultivable for grain on account of the shortness of the summer and of the danger of frosts during the growth and ripening of the grain. This in turn is directly connected with the altitude. At the point where the Sevier leaves its main valley and enters the Pavant range, its altitude is 5,050 feet above sea-level. At Gunnison it is 5,150 feet.

The altitudes of the San Pete Valley are approximately as follows:

Feet.
Manti 5,350
Ephraim 5,450
Moroni 5,500
Springtown 5,550
Mount Pleasant 5,600
Fairview 5,725
Fountain Green 5,650

Beginning at Gunnison and ascending the Sevier along its main course, the altitudes are as follows:

Feet.
Gunnison 5,100
Salina 5,175
Richfield 5,300
Monroe 5,350
Joseph City 5,375
Marysvale 5,600
Circle Valley 6,000

Taking the East Fork in Grass Valley:

Feet.
Head of East Fork Cañon 6,300
Cousharem 6,700
Daniels’ Ranch 7,000

Taking the South Fork:

Feet.
Head of Panguitch Cañon 6,250
Panguitch 6,400
Hillsdale 6,550
Junction of Mammoth Creek 6,900

In the San Pete Valley, which has been cultivated as far up as Mount Pleasant for twenty years, I cannot learn that any crop has ever been injured by frosts, and we may therefore conclude that this valley is safe from such an attack, unless a most abnormal one. The same may be said of the main Sevier Valley from Joseph City downward. From Joseph City to Circle Valley there is a relatively small proportion of irrigable land, but such as there is may, I think, be regarded as safe from frost. Circle Valley, where the two forks unite, has been cultivated for cereals for four years, and has not yet suffered from frost, and it is fair to assume that such a calamity will be very infrequent there, though it may not be possible to say there is no danger. In Panguitch Valley, a severe frost in August, 1874, inflicted great injury upon the crops, and only a small quantity of very inferior grain was harvested. But in 1875, 1876, and 1877, excellent crops were secured. Above Panguitch the amount of arable land is not great, and the danger to crops is increased. In Grass Valley there is a magnificent expanse of fertile arable land, but there can be no question that a large portion of it is so liable to killing frosts in August, or even in July, that the cereals cannot flourish there. The lower portion of the valley, near the head of East Fork Cañon, is more hopeful, and it is probable that a large majority of crops planted there will mature, though occasional damage may be reasonably looked for. The general result may be summarized as follows: Below 6,000 feet crops may be considered as safe from serious damage by frosts. From 6,000 to 7,000 feet crops are liable to damage in a degree proportional to the excess of altitude above 6,000 feet. Above 7,000 feet the danger is probably such as to render agriculture of little value to those who may pursue it.

The climate has shown in past times a longer period of variation than the annual one. Panguitch was settled once in 1860, but was abandoned on account of the destruction of crops by the frosts. The settlement was renewed in 1867, and again abandoned, in consequence of the attacks of Indians. It was settled a third time in 1870, and, though crops have occasionally been injured, the agriculture has on the whole proved remunerative.

Let us now look at the irrigable lands of the Sevier and its tributaries. Above the town of Panguitch, on the South Fork, there is a considerable area of arable land, which could be easily reached by canals from the main stream and below 7,000 feet altitude, but for want of a detailed survey it is impossible to do more than guess at the area. I think, however, that 8,000 acres would be the maximum limit. This portion of the valley is liable to killing frosts, though during the last three years it has not suffered from this cause. In the long run, I believe agriculture will not prove remunerative here. From Panguitch northward to the head of the Panguitch Cañon, a distance of 18 miles, is a broad valley, averaging 5 miles in width, a very large portion of which is irrigable, provided the water supply is adequate. At least 24,000 acres may be cultivated without resort to anything more than the usual methods of distributing the water; but not the whole of this area is fertile. The greater part of the area of Panguitch Valley is composed of alluvial slopes, or, as they have been termed by geologists, alluvial cones. Although these surface features are presented in a somewhat more typical and striking manner in Grass Valley, yet they are well enough exhibited here; and as they have an important relation to the subject, I will briefly discuss them.

In a mountainous country like this, where the melting of the snows in spring or heavy rainfalls at other seasons create sudden and great torrents, large quantities of detritus are carried down from the mountains into the valleys. These mountain streams, which in summer, autumn, and early winter are ordinarily either very small or wholly dried up, may upon certain occasions become devastating floods. The bottoms of the ravines are steep water courses, down which the angry torrents rush with a power which is seldom comprehended by those who dwell in less rugged regions. Huge boulders weighing several tons, great trees, with smaller débris of rocks, gravel, sand, and clay, are swept along with resistless force, until the decreasing slope diminishes the energy sufficiently to permit the greater boulders to come to rest, while the smaller ones are still swept onward. The decrease of slope is continuous, so that smaller and smaller fragments reach a stable position, and only cobblestones, gravel, or sand reach the junctions of the streams with the main rivers. Around the openings of the greater gorges and ravines the deposits of coarser detritus build up in the lapse of time the alluvial cones. As it accumulates, each torrent builds up its bed and constantly changes the position of its channel, and with the mouth of the ravine for a center it sweeps around from right to left and left to right like a radius, adding continually, year after year, to the accumulations of detritus. Thus a portion of a flat cone is formed, having its apex at the mouth of the ravine. At the foot of mountain ranges these alluvial cones are formed at the mouth of every ravine, and are sometimes so near together that they intersect each other, or become confluent. They are composed of rudely stratified materials, ranging in size or grain from fine silt and sand to rounded stones of several hundredweight, and occasionally a block of a ton or more may be seen near the apex of the cone. In regions where the rocks are soft and readily disintegrated the stones are more worn, less in number, and smaller in size, and this is the case generally with unaltered sedimentary rocks. But in valleys running among volcanic ranges, the much greater hardness and durability of the materials preserve them from disintegration, and the stones are more numerous, larger, and less worn by attrition, composing indeed a very large proportion of the bulk of the alluvial cones. A large portion of the valley of the Sevier lies in the midst of a volcanic region, and its sides are everywhere flanked with these alluvial cones, which are very stony and gravelly. The lower portion of the Sevier is in a country made of sedimentary beds, and though the alluvial cones are equally common, they consist of finer material, and are less burdened with stones.

The Panguitch Valley is between volcanic plateaus, and most of its area consists of alluvial cone land, which is no doubt fertile wherever the stones and rubble are not sufficient to prevent plowing and planting, but this difficulty must render it at least very undesirable. There is, however, a large area of land of another description in Panguitch Valley, composed of the finest silt brought down by the gentler current of the river itself, and deposited within its own basin. This is good bottom land, and the amount of it I estimate at not less than 7,000 acres. It has already been remarked that Panguitch Valley stands at an altitude above 6,000 feet, and is not free from danger of summer frosts. These have been known to destroy or seriously injure the grain, though in a majority of years crops will no doubt be safely harvested. Whether the danger is such as to make agriculture unremunerative in the long run experience can alone demonstrate.

Following the South Fork of the Sevier downward through the Panguitch cañons, the next important agricultural area is Circle Valley. This is a broad, nearly circular area, situated in the midst of scenery of the most magnificent description. Upon the east and west sides rise those gigantic cliffs which are the peculiar feature of the scenery of this elevated region, looking down upon the valley below from altitudes of 4,000 to 5,000 feet. This valley also has upon its sides long sloping areas of stony alluvial cones, full of blocks of trachyte and basalt washed down from the cliffs above. It has also a large area of arable land. There is in addition, a certain area of sandy land of an inferior degree of excellence. The area of best bottom land will probably reach as high as 6,000 acres. In this area there is probably very little danger from early frosts, as the 6,000 feet contour passes through the middle of the valley, and, as already stated, the areas which lie within this limit are reasonably safe from this occurrence. At the north end of Circle Valley we find the junction of the two main forks of the Sevier River. From the junction the main stream runs northward for nearly 20 miles, and throughout this entire stretch there is but little arable land. Upon both sides of the river there are long alluvial slopes, made up of stony materials and coarse gravels, through which a plow could scarcely be driven. A portion of the way the river runs between rocks and low cliffs and in abrupt cañons, cutting through old trachyte and basaltic outflows. Reaching Marysvale, we find a sufficient area for three or four good sized farms, consisting of bottom land of the finest quality, which can be watered either from the Sevier River itself or from two considerable affluents which come roaring down out of the Beaver Mountains. North of Marysvale is a barrier thrown across the valley, consisting of rugged hills of rhyolitic rocks, through which the river has cut a deep cañon; but agriculture in any portion of this barrier is out of the question. The river emerges from it at the head of what may be called its main or lower valley, near the Mormon settlement called Joseph City. From this point northward we find what must undoubtedly become the great agricultural area of southern Utah. It is a magnificent valley, nowhere less than 5 miles in width, and at least 60 miles in length, with abrupt mountain walls on either side, and almost the whole of its soil consisting of alluvial cones, and susceptible of a high degree of cultivation. The limit of the amount of land in this valley which can be irrigated is measured by the quantity of water which can be found to turn upon it. The western side of the valley is flanked by abrupt walls of sedimentary rocks. As I have before stated, the alluvial cones which find their origin in the degradation of these sedimentary walls are invariably composed of finer materials than those which come from the breaking up of volcanic rocks. The soil, therefore, is much more readily plowed and planted than the corresponding cones farther up the river. The surface of these cones, moreover, is coated with a thick layer of fine loam, and it is not until penetrated to a considerable depth that we come upon a coarser material. This portion of the valley of the Sevier has been under cultivation for more than eight years. The art of irrigation has also reached a certain stage of advancement, at which it can be studied with some interest. A canal of sufficient magnitude to carry the entire body of the water of the Sevier during the dry season has been run for a distance of 8 miles, and is used for irrigating the large grain fields which lie around Richfield; and, as irrigation is now conducted, the entire flow of the stream is turned through this canal after having been employed for irrigating the various fields, which extend for the distance of nearly 7 miles. The total amount of irrigable land which may be found between Joseph City on the south and the point where the Sevier leaves its proper valley, 65 miles to the northward, cannot be much less than 90,000 acres. The limit of irrigation throughout this entire valley is the limit of the water supply.

There is one other valley to which we must advert, namely, the valley of the San Pete. This is fully equal in fertility and in the convenience of every element connected with irrigation to the best part of the main valley of the Sevier. The San Pete is a stream of considerable magnitude, and experience has shown that it is probably capable, under a more improved system of irrigation than that now in use, of watering the greater portion of its valley. The cultivable acreage of the San Pete Valley is about 55,000 acres, provided the whole could be watered.

The quantity of water carried by the Sevier will now be considered. This, of course, is highly variable from month to month. The time for measurement, if the true irrigating capacity of the stream is to be considered, should be that time at which the ratio of water in the stream to the amount required is smallest. At different stages of growth of the crops the amount of water required differs considerably. The largest amount is needed about the time the seeds of the grain begin to fill out. Ordinarily this is in the latter part of July and early in August throughout the lower and most extensive portion of the valley, and a week later in the upper portions. At this season the water is not at its minimum. There is a gradual diminution of the flow during July, but the great shrinkage of the stream occurs during the middle of August, just after, or sometimes even during, those irrigations in which the greatest amount is required. The critical period of the crops occurs, therefore, just before, and sometimes dangerously near, the period of rapid decline in the water supply. It will therefore be evident that it is not a very easy matter to determine the exact stage of water which can serve as a criterion of the irrigating capacity. My own measurements, however, were hardly a matter of choice, but were made at the most advantageous period which could be selected without interfering with the primary objects of the expedition.

The Sevier was measured at the junction of the two main forks, at the north end of Circle Valley, on the 6th and 7th of July. The method adopted was first to find a section of the water at a given point by soundings and by actual measurement of the width of the water surfaces, and measuring the surface velocity by means of floats. The most probable mean result of several measurements was found to be 410 cubic feet per second for the East Fork, and 450 feet per second for the South Fork, or a total of 860 feet.

While this measurement was made the South Fork was being drawn upon above for the watering of about 1,100 acres near Panguitch, 35 miles farther up the stream, and also for watering about 600 acres in Circle Valley, about 3 to 4 miles above. The amount of water used in Circle Valley was probably greater than that at Panguitch, since the method employed was much more wasteful, and no provision made for returning the tail water to the stream. On the other hand, a large proportion of the tail water from both places finds its way back to the channel in spite of waste, but how much it is impossible to conjecture. I think, however, that 75 cubic feet per second would cover the loss from these sources.

Below the point of measurement the Sevier receives the following affluents: At Van Buren’s ranch is a cluster of very large springs, furnishing about 55 cubic feet per second. Between Van Buren’s and Marysvale are three streams, yielding together about 30 feet, and Bullion Creek at Marysvale carries about 40 feet. There is still another affluent at Marysvale with about 30 feet. Finally, Clear Creek, north of Marysvale Cañon, gives about 45 feet, making the total contributions between the junction of the forks and Joseph City about 200 feet.

At Monroe a stream issues from the Sevier table, and is used for the irrigation of the field cultivated by that settlement. Its flow is estimated at 40 feet in the middle of July. At Richfield, on the other side of the valley, is a stream coming from the Pavant, with a flow of about 20 feet, and at Glencove a stream of 25 feet. At Salina is a large tributary issuing from a great cañon through the north end of the Sevier Plateau, and its measurement indicated a flow of 165 feet. The total between Monroe and Salina, inclusive, would thus reach 250 feet, to which might be added some smaller tributaries, not specifically mentioned, amounting perhaps to 10 feet, giving a total of 260 feet. Adding this to the tributaries between the upper forks and Joseph City, and to the main river itself, we have, as the total above Gunnison, 1,320 feet. This estimate being for the early part of July, and obviously largely in excess of the amount which is available at the critical period, in the last week of that month and the first week in August, what allowance should be made for the diminution of supply during the month of July it is difficult to determine. The smaller tributaries, as a rule, shrink much more than the larger. Those which enter the stream lower down decline more during July than those which join it farther up. Taken altogether, I am satisfied that it would be unsafe to estimate the irrigating capacity in the first week of August at more than 60 per cent. of that found in the first week of July, and I regard 50 per cent. as a much more probable estimate. For want of a better one, I adopt it, and this gives the estimated irrigating capacity of the Sevier and its tributaries above the junction of the San Pete at 660 cubic feet per second during the critical period.

The water supply in the San Pete Valley was measured by Mr. Renshawe during the latter part of July, and found by him to be as follows:

Volume of flowing water, in cubic feet per second, of streams in San Pete Valley.

Feet.
Pleasant Creek 28
Ephraim Creek 28
Manti Creek 28
Springtown Creek 14
Fairview Creek 10
Wales Creek 6
Fountain Green 10
Moroni 10
Creek between Ephraim and Manti 5
Creek between Manti and Gunnison 5
Creek above Fairview 2¹⁄₂
Twelve-mile Creek 28
San Pete at Gunnison 60
Total 234¹⁄₂

This estimate is also liable to reduction, being undoubtedly a little in excess of the amount available at the critical period. This reduction may be as great as 15 per cent., which would leave very closely 200 cubic feet as the water supply of the San Pete Valley, which, added to the total of the Sevier above Gunnison, gives for the whole drainage system of the Sevier River a water supply of 860 feet per second at the time when the greatest amount is required.

The next factor to be inquired into is the amount of land which a cubic foot per second of water can irrigate. This is, of course, highly variable, depending upon the nature of the soil, and the economy with which the water is applied, and the frequency of the irrigations. New lands freshly broken require much more water than the older ones which have been planted and watered for several years; and in fact the quantity diminishes with each season for a long term of years. In the San Pete Valley, which has been longest cultivated, the decrease in the amount of water applied to the oldest lands has not yet ceased, though some fields have been cultivated with regularity since 1857. The fresh soils are highly porous and absorptive, requiring a large quantity of water for their irrigation, and not retaining this moisture well under the great evaporative power of a dry and hot atmosphere. With successive irrigations, the pores of the soil are gradually closed and the earth is slowly compacted by the infiltration of impalpable silt brought by the irrigating waters. It absorbs water much more slowly, and retains it a much longer time. There is, however, a check to this increased irrigating power, arising from a wasteful mode of agriculture. It has not been the practice to employ fertilizers, nor any other conservative means of keeping up the fertility of the soil, and the yield of the crops growing smaller, the old lands are frequently abandoned, and fresh adjoining lands are broken, planted, and watered. It has been the practice to cut the straw, which is never returned as mulch; and, as there is but little rotation in crops, the result can be easily comprehended. So long as new land costs nothing but the labor to clear of the Artemisia or sage brush, there is always the tendency to invade it as rapidly as the old lands show signs of fatigue. Thus the waters are constantly irrigating every year a large proportion of new land, and the consumption of water is correspondingly great.

A serious loss of water and fertility is produced by any method of irrigation which employs more water than is just sufficient to saturate the soil. Whatever water runs off from a field carries with it great quantities of mud and fine silt, together with the most precious elements of fertility. These elements are the soluble alkaline salts and organic manner which are readily taken up by the water, and once removed are not speedily restored. A field which is so irrigated that a large surplus of water is continually running from the tail ditches during the flow will rapidly deteriorate in fertility. But a field which receives water which is allowed to stand until it has soaked into the earth, without any surplus passing into the tail ditches, will increase in fertility. These irrigating waters bring with them a sufficiency of plant food to compensate, and more too, for the drain upon the soil caused by the harvest; but they will carry off more than they bring if they are permitted to run over the field and escape from it, instead of being caught and held until they are absorbed. It is not always practicable to attain this exact distribution of water, and many cases occur where great expense and labor might be required to arrange the ditches and fields in this manner. Ordinarily, it is cheaper to throw away old land and take up new than to improve the system of irrigation, and there are many fields in the valley of the Sevier which have been abandoned because the fertility of the soil has been washed out by a reckless method of irrigation. Connected with this is another source of waste, arising from very unequal requirements of contiguous areas, in consequence of which many lands, especially old ones, are liable to be excessively watered. When a community farms a large number of small fields, using water from the same canals, it is usually impossible so to regulate the distribution of the privilege that each field will receive the exact amount it needs. Some fields can remain unwatered much longer than others, and the tendency always is to get as much water as possible—each farmer fearing a deficiency of water and wasting its surplus. Experience on the part of the watermasters and a more and more settled habit in the lands themselves gradually diminish this source of loss and create economy. Far better results, therefore, may ordinarily be anticipated in old lands than in new. Better results, also, are found where circumstances render difficult or impracticable the abandonment of old fields for new, and this is ordinarily in those portions where the water is nearly or quite sufficient for all the irrigable land, and where all the irrigable land is taken up.

Recurring, then, to the inquiry as to the amount of land which a cubic foot per second of running water will irrigate, this area is in many of the new lands as low as 40 acres, and it seldom exceeds 80 acres with the old lands. Probably there are very few regions in the world where the demand of the soil for water is so great as here where the supply is so small. In California a cubic foot of water is said to be capable of irrigating more than a hundred acres, in India 200, and in Spain and Italy a much larger area. The reason is obvious. It is the direct consequence of the extreme aridity of the climate of Utah. The irrigating capacity of the unit of water is even less in the southern counties of Utah than in those around Great Salt Lake. Mr. Gilbert’s estimate of 100 acres for this last locality being accepted as the best that can be hoped for, it will not be rating the factor too low to say that 80 acres is the best that can be hoped for in the valley of the Sevier. The present factor will not, I am convinced, have a higher average value than 50 acres.

The total acreage, therefore, which can be irrigated in the drainage system of the Sevier by the present system of watering and of agriculture may be estimated at about 43,000 acres, and the greatest improvements and economies in the system of farming and watering cannot, with the present water supply, be expected to raise the irrigable area above 70,000 acres.

Districts.Square miles cultivated during 1877.Acres cultivated during 1877.Square miles of irrigable land. Acres irrigable land.
San Pete Valley 17 11,000 31.2 20,000
Gunnison 4.4 2,800 6.2 4,000
Sevier Valley above Gunnison 16.5 10,500 54.7 35,000
Circle Valley 1.2 750 6.3 4,000
Panguitch and above 2.8 1,800 11 7,000
Total 41.9 26,850 109.4 70,000

Nevertheless, I am persuaded that it will be practicable to extend the possibility of irrigation by an increase of water supply to a degree sufficient to irrigate every acre of the main valley of the Sevier which can be reached by canals, and which is also fit for cultivation. It is by the method of artificial reservoirs. There is probably no region in the world more admirably suited to the easy, cheap, and efficient application of this method than this very region drained by the Sevier River. The sources of this river are found at high altitudes, but these high places are not mountains in the ordinary sense, but great plateaus with broad summits. These table tops have vast numbers of large basins broad enough for great ponds, which are now drained by narrow gorges cut through volcanic sheets and leading down to lower levels. These gorges are in most cases narrow cañons, which, being once barred across, will dam the waters above them. I could not select a better example than the following: About 15 miles southwest of the town of Panguitch is a broad basin, the central part of which is occupied by a shallow lake, about 1¹⁄₄ miles long and nearly a mile wide, called Panguitch Lake. Its altitude is about 8,200 feet. It is completely surrounded with barriers, nowhere less than 100 feet in height, and finds its drainage through a narrow cleft on the northeast side. It receives the influx of two fine streams, which in May and June must carry heavy floods of water from the lofty rim and broad watershed of the Panguitch Plateau lying to the westward. Even in August their united flow must reach 50 feet per second. By throwing a dam 30 feet high and 50 or 60 feet long across the outlet between its walls of solid trachyte, a lake would be formed with an area of 6 or 7 square miles. There are many such basins upon the Panguitch Plateau, and it would be a low estimate to say that it would be possible, at comparatively small expense, 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 Cañon 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 Cañon, 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 immediate surface. By capillary action, this water always tends to diffuse itself throughout the loose materials which make up the overlying soils. As fast as it is evaporated at the surface, more water from below rises by capillary action to take its place. When the air is exceedingly dry, as it invariably is in summer throughout the whole Rocky Mountain Region at moderate altitudes, the evaporative power becomes so great and extends to such a depth below the immediate surface, that we are unable to recognize the slightest traces of moisture indicating that evaporation is going on. The water which may have accumulated beneath has gradually risen by percolation through the interstices of the unconsolidated materials of the soil, bringing with it whatever soluble salts it may have taken into solution during its sojourn beneath the surface. These soluble salts are left at the surface by the final evaporation of the water, and, as the process is continuous until the reservoir beneath is exhausted, the salts accumulate. Contrast this now with the action going on in a moist country. Here the copious waters wash the soils as rapidly as the salts come up from below, and carry them in solution into the drainage channels. During the greater part of the year the movement of the waters is partly from the surface downward into the subterranean water courses, from which they emerge in springs; partly by surface drainages into rills, and thence into living streams. By both movements, any tendency to accumulate soluble salts at the surface during the relatively brief periods of dryness is prevented. In a dry country the periods of dryness are very much longer, and the rainfall is seldom sufficient to wash the accumulated salts from the soil. There is, however, usually a limit to this accumulation, since at long intervals rains occur sufficient to remove a large portion of the salts. The difference between a dry and wet country in this respect is therefore one of degree rather than of kind. In a dry country the periods of accumulation of salts at the surface are long and continuous, while the washings of the soil are rare and imperfect. In a wet country the periods of accumulation are short and rare, while the washings are frequent, copious, and thorough.

The saline materials vary widely in character and constitution. They are, however, chiefly salts of soda, lime, potash, and magnesia. Sometimes they exist in the condition of chlorides, sometimes of carbonates, and sometimes of sulphates. The reactions from which they are derived are many, and it will be proper here to give only a few illustrations. A portion of the salts of magnesia and soda are derived from the decomposition, by atmospheric influences, of volcanic, granitic, and other crystalline rocks. Where these materials exist in the form of felspar, hornblende, and pyroxene, the great decomposing agent is water charged with the carbonic acid of the atmosphere, by the action of which soda, magnesia, and lime are, with inconceivable slowness, dissolved out of the constituents of these rocks. There is no stream, however pure it may apparently be, which does not carry more or less of chlorides and carbonates in solution. The sulphates are derived mainly from subterranean sources. In the Rocky Mountain Region, one of the most common forms of sulphate is found very abundantly in the rocks of the Carboniferous, Triassic, Cretaceous, and Tertiary Ages, in the forms of gypsum and selenite, which are sulphates of lime. Whenever waters containing carbonate of soda are filtered through strata containing these sulphates, a double decomposition takes place, by which carbonate of lime and sulphate of soda are formed. The carbonate of lime is very slightly soluble in water, while the sulphate of soda is highly so, and it is well known that waters emanating from the sedimentary rocks just spoken of are very frequently highly charged with it. Such, doubtless, is the origin of this mineral in the so called alkaline waters of the west, and of all the soluble minerals which pass under the name of alkali it is one of the most common. Carbonate of soda is also abundant in the soils. It is frequently found in the summer time, coating the surface of bottom lands which earlier in the season have been submerged by the augmented streams. Common salt (chloride of sodium) is even more abundant than the sulphate. It is well known, however, that many of the sedimentary rocks, particularly those of the Triassic and Jurassic Age, contain an abundance of it, and there are many localities in the west where a very fair article of common salt is obtained by the lixiviation of the detritus of the red Triassic rocks. Incrustations of these soluble saline materials occur most abundantly in the vicinity of the rivers and in the bottom lands. This may at first seem somewhat strange, but it is susceptible of a ready explanation. In order that these salts may accumulate at the surface, there must be going on continually a slow transmission of moisture from under ground upward, and since a continuous supply of water is more frequently found in the bottom lands than elsewhere, it follows that the conditions of these accumulations are here more frequently fulfilled. They may, however, and do occur at localities which probably contain subterranean reservoirs of water, which are annually filled during the wet season. Sometimes these salts are so abundant that the land requires a thorough washing before it is fit for agriculture, and the Mormons have on several occasions, when founding settlements, been obliged to allow the waters from their ditches to leach the land for many months, and in one or two cases for two, and even three, years, before a good crop could be raised. There is no difficulty, however, in removing any quantity of these readily soluble salts from the soil, provided this leaching process be continued long enough; and it is usually found that lands which were originally highly akaline become, when reclaimed from their alkalinity, among the most fertile.

There yet remains for mention a number of small areas served by some minor streams in southwestern Utah. These little creeks head in the mountains, but are soon lost in the deserts of that arid and torrid region, none of their waters finding their way to the ocean. The greater number of them belong to the drainage basin of Sevier Lake. In each case the water supply is small, and inadequate to supply the available land. In nearly every case the competence of the supply has been determined in the most practical way—by the operations of settlers; but some allowance has been made for an increase of the irrigable land by the more economic use of the water. This can be accomplished by the construction of better waterways, and by more carefully flowing the water over the lands.

The following table exhibits the extent of these areas:

Districts. Square miles. Acres.
Cherry Creek .2 100
Judd Creek .2 100
Levan 3.1 2,000
Scipio 2.6 1,700
Holden 1.6 1,000
Fillmore and Oak Creek 5.5 3,500
Meadow Creek 1.9 1,200
Kanosh 3.1 2,000
Beaver Creek and tributaries 21.9 14,000
Paragoonah 1.5 1,000
Parowan 1.5 1,000
Summit .6 400
Cedar City, Iron City, and Fort Hamilton 3.6 2,300
Mountain Meadows .3 200
Pinto .3 200
Hebron 1.6 1,000
Total 49.5 31,700

CHAPTER IX.
IRRIGABLE LANDS OF THAT PORTION OF UTAH DRAINED BY THE COLORADO RIVER AND ITS TRIBUTARIES.

By A. H. Thompson.

That portion of Utah drained by the Colorado River and its tributaries belongs to a great basin limited on the north by the Uinta Mountains and on the west by the high plateaus that separate the drainage of the Colorado from that of the salt lakes of the interior, and extending beyond the limits of the Territory on the east and south. The floor of this basin is extremely rough, being broken by isolated groups of rugged mountains, by plateaus encircled with cliffs of almost vertical rock, by mesas and amphitheaters, and huge monumental and castellated buttes. Everywhere the surface is cut and carved with a network of cañons, hundreds and often thousands of feet in depth.

The main channel through which its drainage passes to the sea is the Colorado, and its proper upper continuation, the Green River.

The principal tributaries to these streams from the east are the White, the Grand, and the San Juan Rivers—all rising in the high mountains east of the Territory and flowing in a general westerly course—the White entering the Green River, the Grand uniting with the Green to form the Colorado, and the San Juan entering the latter about 125 miles below the junction of the Grand and the Green. The Virgin, the Kanab, the Paria, the Escalante, the Fremont, the San Rafael, the Price, the Minnie Maud, the Uinta, and Ashley Fork are the principal tributaries from the west.

This portion of Utah is but sparsely settled by white people, the only permanent locations being in the southwestern part, and in the Uinta Valley at the north. Information concerning its agricultural resources is limited, being confined, except in relation to the localities before mentioned, to data collected by the geographical and geological parties of this survey. Many of the streams have been visited but a single time, and different streams at widely different dates, during a field season. Often the exigencies of the survey prevented as close an examination into the flow of water, and the location and character of the soil of the arable tracts, as was desirable; yet, on the whole, it is thought that the data collected can be relied upon as a very close approximation.

The climate of the basin is one of extreme aridity. The prevailing wind is westerly. The high plateaus and mountains forming the western rim of the basin force these winds up to an altitude above the sea of over 10,000 feet, and thus act as great condensers to deprive them of their moisture. Flowing down from the higher lands into the warmer regions below, their capacity for absorption is increased, and during the greater portion of the year the winds abstract from rather than add to the humidity of the lower altitudes. But little is known concerning the actual amount of precipitation of moisture within the basin. Below an altitude of 7,000 feet it is very small, probably not over an average of 5 inches yearly. At higher altitudes it is much greater, probably reaching 24 inches, but this is mostly during the winter months and in the form of snow.

The elevation of the region under consideration is from 2,500 feet to 11,500 feet above the sea, thus giving great range in temperature. In the valleys of the extreme southwestern portion an almost subtropical warmth is experienced, and the different valleys containing arable lands we pass from these by insensible gradations to those where frosts occur during every month in the year. Generally, the limit of successful cultivation of the soil is below 7,000 feet.

In this portion of Utah irrigation is essential to agriculture. If all the single acres it is possible to cultivate without artificial irrigation were aggregated, I do not believe the sum would reach one-fourth of one square mile, and every foot of this meager amount is irrigated naturally. Springs are of infrequent occurrence. The great source of the water supply is the streams fed by the rains and snows of the high table lands and mountains. All these streams have a rapid fall in their upper courses, and are here often of considerable size; but upon reaching the lower and more level country their waters are rapidly absorbed by the porous soil and evaporated by the higher temperature. So great is the loss from these causes that some streams fail to reach the main drainage channel during the warmer months, and all are greatly shrunken in volume. All the arable lands—or lands where altitude, slope of surface, and quality of soil permit successful cultivation, if a supply of water can be obtained, and from which lands to irrigate, or irrigable lands, may be selected—are in the valleys adjacent to the streams. Usually this area in many valleys is in excess of that which the water in the streams can irrigate, and choice in the location of lands to cultivate is often practicable. In this report I have considered irrigable lands to be such only as possess all the necessary qualifications of altitude, slope of surface, and fertility of soil, and have, in addition, an available supply of one cubic foot of water per second for each hundred acres. The great dissimilarity between the valleys makes it desirable to consider the drainage basin of each separately, in respect to arable lands, irrigable lands, volume of water, and practicability of increasing this supply during the irrigating season.