Popular Science Monthly/Volume 71/July 1907/Control of the Colorado River Regained
|CONTROL OF THE COLORADO RIVER REGAINED|
LOS ANGELES, CAL.
THE Colorado River, creator of the much-discussed Salton Sea, has at last been captured. Its waters, always of uncertain quantity and consequently often threatening, no longer are poured into Salton Sink by way of a river-like irrigation ditch, but instead flow peaceably into the Gulf of California as in the days before man had tampered with it for irrigation purposes. And incidental to the river's capture, Imperial Valley, that new agricultural region rescued by irrigation from the Colorado Desert, an area lying below the level of the sea, and a region that is some day destined to become worth millions of dollars, is no longer in danger of being inundated by the murky waters of this treacherous "yellow dragon" and consequently wiped practically out of existence.
The going astray of the Colorado River, and the trouble incidental thereto, which was described in The Popular Science Monthly some months ago, has occasioned much study and deep concern by engineers all over the country, and has attracted the attention of the heads of two governments—the United States and Mexico. It has created an inland sea in Salton Sink, adjacent to Imperial Valley, that covers about 400 square miles, destroyed the works of the New Liverpool Salt Company, caused three different removals of several miles of the Southern Pacific Railroad, and necessitated the expenditure of many thousands of dollars towards its control, besides threatening to submerge the Imperial Valley, several small cities of considerable importance and a number of rich mineral deposits.
The trouble with the Colorado River, it will be recalled, began in September, 1904. The California Development Company, promoters of the Imperial land colony, needed more water for agricultural purposes than their old irrigation ditch was then supplying, and to remedy the shortage an incision was made in the banks of the river at a point about four miles below the old tapping point, and below the international boundary line between the United States and Mexico. A flood in the river soon cut this new channel so deep as to place the flow beyond control. Gradually this ditch was eroded into a river that at times carried the entire flow of the Colorado River, sometimes amounting to 40,000 second feet of water, and poured it into Salton Sink.
In all, six attempts had been made to capture the runaway river before the last and successful one. The first five, however, were poorly carried out and practically amounted to nil in the final success. The sixth proved better, and for a time it seemed to solve the problem. It was completed on November 4, 1906, and on the night of December 7, 1906, during the flood, the river again ate its way through the barrier of willow matting, piles, rocks and dirt and once more wended its way toward Salton Sink. This dam, called the Hind Dam, in honor of the field engineer, Thomas J. Hind, therefore withstood the rebellious-inclined Colorado for a period of only thirty-three days.
The Hind Dam, which, though not a success of itself, aided in the final capture, was a conglomerate creation 170 feet wide at the base, 30 feet across at the top and 35 feet high at the deepest places in the break. It was 3,000 feet in length, of which 600 feet was of rock construction and 2,400 feet of earth and gravel. Its foundation consisted of a heavy, strong mat of willow and cable, held in place by strong piles, about 1,100 in number and from forty to sixty feet in length. The mat was created by the use of 2,200 cords of willow, cut by Indians, 40 miles of five-eighths-inch woven steel cable, and 10,000 cable clips. It was 100 feet wide and 800 feet in length, divided into eighteen sections, and was laid across the river by being uncoiled from a barge floated across the stream.
The piles driven into the mat were also made to serve as a support for a temporary railroad. From this road carload after carload of material was dumped into the gap, in all there being 70,000 tons of rock, 40,000 cubic feet of gravel, 40,000 cubic feet of clay, and 100,000 sacks of sand, besides about 500,000 yards of dirt thrown up by teams and dredges. To carry on this work as many as 1,100 men and 600 horses and mules, besides several steam dredges, shovels, pile drivers and an almost endless string of freight cars, were employed at one time. The cost of the work to the Southern Pacific Railway Company, which, headed by Engineer Epes Randolph, engineered the undertaking, reached an average rate of $10,000 per day for one hundred days.
The break that occurred in the river after this dam was completed, in December, was at a part about 2,500 feet below the works, and was 1,100 feet wide. Colonel Randolph again assembled his forces, placed E. K. Clark, engineer of the Tucson division of the Southern Pacific Railroad, in direct charge, and work was recommenced to solve this troublesome problem. Another dam, called the Clarke Dam, was built and by it the Colorado River has at last been permanently confined to its old channel.
To build this dam no attempt to follow science was made. The Southern Pacific placed their entire road subject to the orders of the engineers, and materials of almost every kind were rushed to the break from points far and near as fast as it could be taken care of. Piles were driven, a temporary road was constructed across the break, and there was almost a continual dumping of rock, gravel and dirt into the gap. A carload of material was dumped every seven minutes both day and night, and in the short period of thirteen days 100,000 tons were disposed of, bringing the dam up to water level. Much of this material was hauled a distance of 380 miles.
The Clarke Dam was practically completed February 10, 1906, and the river was declared conquered. The dam proper is 1,200 feet in length, of which 700 feet is of rock and 500 feet of gravel and earth. Work, however, did not cease with the completion of the dam, and, since February 10, several miles of earth embankment have been built to insure permanent success. This work will continue until about sixteen miles of levee is built along the west bank of the river, in addition to the two dams with a combined length of 4,200 feet. The river, in the vicinity of the breaks, or dams, and near the international boundary line, for a distance of about seven miles, flows through a throat only 2,160 feet wide, and is considerably higher than the territory lying to the west. The levee follows the river for this distance, and then swings away to the west towards the Black Buttes, leaving the river below this point to follow its own inclinations.
The California Development Company and the Southern Pacific Railroad Company have expended to date upon this work a sum in excess of $3,500,000. This is an enormous sum to dump into a river, it seems, but since the river is captured and all interests immune from further trouble, the two companies feel amply rewarded.
The United States government has inaugurated steps to place Imperial Valley in charge of the Government Reclamation Service, but what the outcome of the move will be is not yet known. In the meantime the California Development Company willto manage the colony, and will install new head-gates for their irrigation ditches and otherwise improve the system. The farmers of the valley feel secure now for the first time in two years, and Imperial Valley promises to become a prospering community.