Popular Science Monthly/Volume 70/January 1907/The Possibilities of Salton Sea
|THE POSSIBILITIES OF SALTON SEA|
LOS ANGELES, CAL.
THROUGH temporarily losing control over the Imperial Valley irrigation system in southern California, there has been suggested the possibility of creating an immense inland sea. This sea would extend from Volcano Lake in Mexico to a point a few miles north of Indio, California, and would spread over an area of 1,700 square miles, with a maximum depth of 280 feet. It would be fed by an irrigation canal intersecting the Colorado River near Yuma, Arizona, and its overflow would be carried into the Gulf of California by the lower part of the same river. It would submerge many acres of irrigated and irrigable land, about a dozen fair-sized towns of more or less importance, several miles of the Southern Pacific Railroad, and a number of rich deposits of valuable minerals. And the ability to create such a sea or lake lies simply in abandoning the present effort to regain control over this irrigation system.
Dealing still further with possibilities of this nature, it may be pointed out that the feed canal of this inland sea could be widened and dredged; and thereby could be created a channel sufficient in dimensions for the entry of boats from the Gulf. This would make it possible for coast steamers to ply between ports on the Pacific Coast and a lake port that might be established near the present site of the town of Indio, at the foot of the eastern slope of the Sierra Madre Mountains, and with a latitude almost parallel with the city of Los Angeles. It is true that if the effort now being made to regain control over this rebellious system of irrigation should be abandoned to-day, and nature be permitted to reign supreme and unaided by man, it would be several years before the Colorado River could possibly complete the creation of the lake;
but since all this territory lies beneath the level of the sea. it is even possible for engineers to change the course of the lower part of the river, so that it would carry water from the Gulf of California to assist in the lake's completion. It may be remarked in this connection, however, that there is no probability at present of such a series of possibilities being permitted to materialize. In the light of present considerations, the value of the land and its products far outweighs the possible benefits of such a lake and inland port. Nevertheless it is a matter worthy of consideration.The Colorado Desert, of which the greater part would be covered by this inland sea, is bounded on the west by the Sierra Madre Mountains, on the north and east by the San Bernardino and Riverside Ranges, and on the east by the Colorado River. As, therefore, would be
shown in a relief map, it is in the shape of an acute triangle, with its base resting upon the Colorado River, on the east side, and extending northwest and up the Coachella Valley toward Mt. San Jacinto. The land slopes gradually from the river northwest to the Salton Sink, which at the lowest point is 280 feet below sea level. Yuma, Arizona, lies at the northeast corner of this triangle, and.is 137 feet above sea level, which, therefore, gives the feed canal, created for irrigating, a fall of 417 feet.
Indio, at the extreme northwest point of the triangle, is 22 feet below sea level, while Volcano Lake, Mexico, is found to be very close to sea level. The town of Indio is the end of a division of the Southern Pacific Railroad, where the company has machine shops and maintains a large force of men. It is also a health resort, and has a fine hotel and sanitarium. The other towns of this sunken area, which would be submerged by such a lake, are: Salton, 265 feet below sea level; Walters, 189; Thermal, 121; Imperial, 65; Alamo Bonito, 186; Coachella, 65; Mortmier, 248; Volcano Spring, 265; Fish Spring, 230, and Mecca, 18.
The town of Imperial, located near the center of the Imperial Valley irrigation colony, is fast becoming a very important little city. Four years ago it was unknown. Its site was only a part of the bare Colorado Desert. An examination of the soil of this vicinity, however, revealed the fact that the only thing necessary to make it productive was water, and in consequence a company was organized to install a system of irrigation. A canal was dug that intersected the Colorado River near Yuma, and by the water thus supplied the region was awakened into life and fertility. As a result, in the past four years, the town of Imperial has come into being, and about 110,000 acres of the surrounding land have been converted into a prospering farming community, with a total population of over 10,000 persons. And the limit has by no means yet been reached, for there is much more of the region in a reclaimable condition.
Up to the time that this irrigation system placed Imperial upon the map, the most important industry on the Colorado Desert was the salt works at Salton. Salton Sink was a vast dry lake of solid salt, and thousands upon thousands of tons of it were mined by simply scraping it up into piles. This industry furnished employment to a large corps of men, and the town of Salton came into being as the result of its being made the headquarters of the New Liverpool Salt Company.
But Salton at present is dead. The town and the works are buried in a grave of water. The person who journeys thither to-day looks upon a vast lake. The homes are deserted, the salt works are abandoned, and Salton Sink, once a dry lake of pure salt, lies transformed
into a billowy sea. Imperial not only became its peer in importance, but its annihilator as well. The savior or the creator of the one became the destroyer and the grave of the other. It was water from the Colorado River that brought Imperial into being, and it was water from the same source that gave Salton its watery burial.
It was not with the spirit of rivalry, however, that Imperial wrought Salton's annihilation. Instead, it is said to have been due to neglect. The main canal for the Imperial Valley irrigation system, which makes use of about fifty miles of what was once the channel of the old Alamo River, draws its water from the Colorado River at a point about ten miles below Yuma, and near the international boundary line between California and Mexico. At this intersecting
point there are three intakes or openings, for each of which there should have been provided a head-gate. This was not done, however, and over a year ago, during high water in the Colorado, these intakes began to admit more water than was necessary for use for irrigation. This surplus, which at times was very large, naturally sought the lowest part of the desert, and in consequence Salton Sink became 'Salton Sea.' Edwin Duryea, Jr., C. E., of San Francisco, who has made a careful study of the situation for the Southern Pacific Railroad, says that since October, 1904, when the canal first began to carry a surplus, the water in Salton Sink has steadily risen at the average rate of over one half inch per day. At times, during floods, this has even been
The result of this surplus flow, due to the loss of control over the irrigation system, has been the creation of a lake averaging about forty miles in length by ten miles in width, and therefore covering an area of about 400 square miles. The Southern Pacific Railroad has been compelled to build many miles of new road to skirt this embryo lake, and the salt works of the New Liverpool Salt Company are immersed in more than twenty feet of water. This was the condition at the close of the year 1905, and the size of the lake is still increasing.
The first attempt to control this rebellious system of irrigation was made in March, 1905. It was a very frail effort, however, and the construction was washed away before it was entirely finished. Four other attempts followed in almost monthly succession, and each in turn met the same fate as the first. Then came the sixth. It, unlike the former ones, was undertaken on a larger scale and with a fuller realization that the problem to be confronted was a grave one. A large force of men was employed, and the attempt was prosecuted with vigor. Two hundred men, twenty teams, two pile-drivers and two stern-wheel river steamers were employed, and the work was carried on night and day. The intention was to construct a 600-foot dam across the west branch of the river, and thereby control the canal service by diverting the water into the east branch—except at such times and in such quantities as were necessary for irrigation. The dam was made of brush woven into mats and reinforced by several rows of piles. The flood of November 29, however, came before it was finished, entirely covering the work with water and washing it away, and thus destroying the sixth attempt.
But the effect of this failure was only to more thoroughly convince the Southern Pacific Railway Company, which had assumed charge of the work in June, that the canal system must be controlled. The company almost immediately, or in December, 1905, awarded a contract for the seventh attempt, and in January of 1906 work was again commenced.
The seventh attempt was pushed with even greater determination than the sixth. A larger corps of men was employed, and the work was planned upon a more substantial scale. It progressed quite slowly on account of high water at different times, but at last it is finished, and the engineers feel confident that the problem, after a year and a half, is now solved. The gates were declared completed about the middle of July, but on account of the swollen condition of the Colorado River they have not yet been tested. The gate on the California side is constructed to admit 20,000 cubic feet per second, and the present flow of the river is in excess of 30,000 cubic feet per second. As soon as the river goes down to its normal condition the gate will be tested, and the engineers who have managed its construction assert that there is no possibility of its not standing the test.
The total cost of the seventh and last attempt to control this irrigation system has been $40,000, or thereabouts. There are two headgates—one, of concrete, on the California side, and one, of wood, on the Mexico side. The one of concrete is built to stand the greater portion, by far, of the strain, and it has every appearance of being amply substantial. The cost of this gate alone was $24,770.47. It necessitated the excavation of 12,637.1 cubic yards of earth and 5,700.81 cubic feet of rock, and required the use of 1,335 barrels of cement, 1,204.85 cubic yards of sand, gravel and rock, 25,722 pounds of steel bars for reinforcement and 791 pounds of expanded metal for gate facings. The work is being engineered by Mr. C. F. Cory, an engineer of wide repute.
Although these dams or head-gates seem to promise a solution to the Salton Sea problem, there is nevertheless excuse for apprehensions of further trouble. The banks of the Colorado River in this vicinity are soft and gravelly and very easily eroded, and on this account there will always be the possibility of new channels being cut around these head-gates, especially during flood seasons.
Whether or not this attempt, when tested, proves successful, however, the damage being continually done to this region can not be expected to end at once. Several hundred thousands of dollars damage has already been done by the truant river, and even if the surplus flow into the Sink is stopped by the new gates, the lake that covers Salton and its salt works will still remain, which evaporation, almost unaided, will have to drain. It will therefore be a long time before Salton, the submerged headquarters of the New Liverpool Salt Works, can be replaced upon the map and the Southern Pacific Railroad reconstructed upon its old road bed.
The damage that threatens this sunken area, in case the river is not controlled, has already been briefly mentioned. If for some unforeseen and improbable cause the present attempt should fail or be abandoned, and no other attempts inaugurated, the water would gradually cut the present irrigation canal so deep that the entire flow of the river would be side-tracked into Salton Sea. The water would slowly rise until a lake would be created as large in area as, or larger than, Great Salt Lake of Utah, and the entire Imperial Valley, which thus far has not suffered, would be covered with water. The lake would not only rise to the sea-level line, but instead, on account of the elevation of the enclosing rim, it would have to reach to an elevation of fifteen or twenty feet above sea level, at which point it would overflow the south rim near Volcano Lake and pass southward until it would again enter the Colorado River near the Gulf. Should it be the desire at any time to convert this area into a sea-level lake, this outlet channel, which would pass over very loose soil, could be dredged very easily into a sea-level inlet from the Gulf.
To fill this sunken area with water from the Colorado River would require many years. The average flow of the river during a year is said to be about 15,000 cubic feet per second. This entire amount conveyed into the lake would be subject to a very great shrinkage from evaporation, and it is even possible that this loss would become so great after the lake had spread over a certain area as to equal the inflow from the river, although such is hardly probable. In any case, all attempted computations of such nature would necessarily be very inaccurate, and may as well be omitted.
In studying the possibility of this area becoming the bed of an inland sea there are even more considerations to be met than are offered by the Imperial Valley land colony and the salt works at Salton. Gilbert E. Bailey, M. E., of Los Angeles, a recognized authority on the mineral resources of California, has made a thorough study of this region, and to the writer he has furnished a partial list of its possibilities in this direction. In addition to the salt deposits, large quantities of nitrate, sulphate and carbonate of soda are found at various points along the rim of the desert, and in the southern part there are about 300 acres covered with mud volcanoes or geysers that spout forth mud of various colors and consistency, containing rare minerals which some day may become of importance. Oil-bearing rocks are found along the west side, forming a belt at the foot of the mountains and extending into the area lying below sea level, from which ooze heavy asphaltic oils, and which will some time develop into a rich oil-producing district. South of the California line, in Mexico, and lying below sea level, there are also valuable and extensive deposits of sulphur; and then in the surrounding mountains, which, however, would not suffer from the lake, are found large deposits of gold, silver and copper and mines of kunzite and tourmaline gems.
Altogether, this is an interesting country. It offers many realities, and as many, or more, possibilities. At present it is battling with an unusual problem, and we are assured by engineers that it stands on the eve of victory—at last. It has met defeat bravely six times, and therefore let us hope that the seventh attempt will be crowned with reward.