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