Irrigation

watering land by means of artificial streams and overflowing. Natural freshets, overflows, and spring floods are not included under the term. The surplus waters of the Nile have been caught in reservoirs and used for irrigation from time immemorial. Rollin's Ancient History gives an account of the rude contrivances used for elevating water into the ditches. The famed fertility of ancient Mesopotamia was due in part to the skilful use of the waters of the Tigris and Euphrates for watering the plains. Smaller areas are yet made fertile by this method. India has 22,500,000 acres of irrigated land. China has maintained extensive irrigation systems since the dawn of history, especially in the rice districts. Portions of Spain, southern France, and the great plains of northern Italy, particularly the valley of the Po, are indebted to systematic irrigation.

For an account of tidewater irrigation, or the flooding of land, as practiced in the Atlantic rice-growing states, the reader is referred to the article on RICE. Irrigation is not a new art in America. When the Spaniards first visited Arizona and surrounding regions they found the remains of extensive irrigation systems in the valleys adjacent to the ruins of the cliff dwellers' ancient cities. Small portions of the old fields were still watered and tilled by their descendants, as is the case at the present day. The early Spanish settlements or missions of the southwest, including those of Mexico and southern California, were famous for gardens and orchards watered by means of irrigation, a knowledge of which the thrifty fathers brought, no doubt, from Spain.

The first systematic attempts by Americans at watering arid lands on a large scale were made by the Mormons. They entered Salt Lake Valley in 1847 and created a veritable paradise out of a desert. It is said that 175,000 inhabitants are maintained on 350,000 acres, a person to each two acres. In California the gardens of Spanish missions and the effects of water escaping from miners' sluices early turned attention to the possibilities of artificial watering. The La Grange system, for instance, cost $5,000,000 and waters 250,000 acres. Forty-six per cent of the present enormous fruit crop of California is produced on irrigated lands.

Horace Greeley, the great Tribune editor, whose advice was "Go west, young man, go west," had unlimited faith in irrigation. He was one of the promoters of the irrigation colony planted at Greeley, Colorado, in 1870. At this time it is estimated not over 20,000 acres were irrigated in the whole United States. From this date onward, however, irrigation canals were extended rapidly. In 1909, 2,500,000 acres of Colorado land were irrigated.

The following statistics, for 1900, are exclusive of rice plantations:

California led in the number of irrigated farms; Colorado in the number of acres. Montana, Utah, Wyoming, Idaho, Nevada, Oregon, New Mexico, Arizona, and Washington followed, in the order named. In 1909 10,000,000 acres or about 2 per cent of our arid land was irrigated. When all the water shall have been used to advantage it is thought that about one-tenth of the arid region will be provided for.

Of the different methods of obtaining water, the gravity method of drawing a supply in ditches from the head waters of streams and mountain lakes is the cheapest. When water cannot be had in this way, it may be lifted by pumps or secured by boring artesian wells. Speaking for 1909, about 200,000 acres of California fruit lands and 400,000 acres of rice land in Texas and Louisiana are irrigated by pumps. Probably 750,000 acres of American soil are watered in this way, but over nine-tenths of our irrigated area obtains water by the first method. In India 13,000,000 acres are irrigated by water pumped from wells. In whatever way water is obtained it is necessarily conducted to the fields in a ditch or flume with some fall. Two or three ways of applying the water are employed. In the Mission and Mexican gardens and in level fields the ground is usually laid of into level plats, or possibly terraces, surrounded by dirt ridges, with the idea of confining the water in pools. When fields have a gentle, uniform slope, it is customary to liberate the water from a ditch all along the upper edge and allow it to spread in a thin sheet over the entire surface of the field and flow into a catching furrow or ditch at the lower side. Another method yet is to plant crops in rows according to the slope of the ground, and liberate water slowly at the upper end of rows, so that it will follow the furrows between the rows to the lower end of the field. Among the interesting devices of irrigation is a canvas dam used to stop the water in a supply ditch and cause it to overflow. It is simply a canvas flag. The pole is laid crosswise of the ditch and the flag is fitted to the bottom and sides of the ditch with a few handfuls of mud. The weight of accumulating water presses the edges against the ditch, forming a perfect temporary dam. Distributing gives lads a fine opportunity to play in the water.

Irrigated crops are surer than crops dependent on rainfall, and averages show that irrigated crops run heavier than rain crops, but an artificial supply of water requires intelligent management. Usually the supply to each farm is determined by water rights. After a farm has drawn its rightful supply the rest belongs to others further along the line, and not another gallon may be drawn from the supply ditch. These remarks apply to a colony ditch constructed under a definite agreement as to how large the stream to which each farm is entitled and what length of time. A water-master or ditch rider is appointed for the season to open and close water gates according to each man's rights. In localities irrigated by no fixed colony plan the first settler to tap a stream or lake is entitled to a ditchful of water at pleasure. He may sell shares in his right, that is to say, in the water of his ditch, but none may draw from the stream higher up or from the same lake to the lessening of his water supply, much less tap his ditch above his farm. After water runs on past a farmer he has no further claim on it. In an arid region any surplus water that passes is eagerly caught by the next man, especially in regions where the streams, usually from the mountain snows, are not sufficient to irrigate more than a fraction of the rich land lying barren below for want of moisture. A farmer needs to know how and when to make the most of his water privileges. Too much water or too long watering is more disastrous than drouth.

The supply of water is naturally limited. In regions of irrigation there is usually more land than water. Land with water rights may be, and frequently is, valued at from $50 to $200 or even $500 an acre, while land of similar quality by the side of it, but without water privileges, is scarcely worth paying taxes on. The acreage of irrigated lands is increasing rapidly. Several large streams, as the Yellowstone, are but partly utilized; yet it is evident that only a fraction of the rich, but arid lands of the West can be reclaimed by surface water. Water for irrigating vegetable gardens is obtained from artesian wells in Algiers, Texas, and South Dakota, but whether artesian water can be had in large quantities is a question for the future.

In 1894 Congress passed the Carey Act. It was considered a freak at the time, but it has proved a wise measure. Under this act the general government offered 1,000,000 acres of semi-arid land to each state that would undertake to irrigate the same and sell to actual homeseekers. Five states, Colorado, Wyoming, Idaho, Oregon, and Washington, accepted the grant. The general plan contemplates the organization of irrigation companies working with private capital under state supervision. The state grants the company a water right for an irrigation project, and sets aside the lands desired for the purpose. The fact that the company is in a sort of partnership with the state enables it to sell irrigation bonds to advantage. The state conveys title to the settler, who pays the irrigation company a fixed price, usually in ten or fifteen installments, for water privileges. The act provides that when ninety per cent of the land has passed into the hands of private owners, the irrigation company steps out, turning the project over to the settlers. The scheme has worked well. A large amount of land has been irrigated. Idaho has asked for and has received an addition 4,000,000 acres. The irrigation companies have made money, settlers have secured valuable homes, and the agricultural interests of the various states have been strengthened materially. Some fault has been found because speculators have gotten in ahead and have derived enormous profits; but that is likely to happen in the development of any new country. The speculator has a particular advantage in instances of this sort, because his lands are necessarily taken in with public lands when an irrigation project is organized.

Of the projects opened under the Carey Act, that of Twin Falls, Idaho, is noted. There are a number of projects in Washington and in the Big Horn Basin in Wyoming. Fifty thousand acres in the valley of the Little Snake in Fremont County, Idaho, have been irrigated. There is a project in southwestern Wyoming on the Green River which embraces 40,000 acres of public land, together with a large block of private lands.

In 1902 Congress passed the so-called Reclamation Act, providing that all funds in excess of five per cent received from the sale of public lands in Arizona, California, Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Utah, Washington, and Wyoming, should be set apart for the irrigation of arid lands in those states and territories. In 1909, the sum of $70,000,000 was in sight for the work. Contracts have been made for the expenditure of about $20,000,000 on irrigation projects in Arizona, Colorado, Idaho, Nebraska, Nevada, and New Mexico. It has been estimated that, in the sixteen states and territories mentioned in the Reclamation Act, there are from 50,000,000 to 60,000,000 acres of reclaimable lands--enough, perhaps, to support a population of 15,000,000 or 20,000,000 people. In each case the cost of the irrigation works is charged pro rata against the acreage which is improved, and the settlers pay the expenditure back to the government in ten installments.

Among systems under way are the Truckee-Carson ditch in Nevada to cost ultimately $9,000,000. It is 200 miles long and will water 385,000 acres, worth at the outset $100,000,000. Progress has been made on a project to water 250,000 acres on the Snake River in southern Idaho. Bids have been opened for a great tunnel twelve feet square and five and one-half miles long to bring water to 80,000 acres in the Gunnison district in Colorado. A plan is under way for irrigating 150,000 acres or more on the North Platte River in eastern Wyoming and western Nebraska. The North Platte dam is to be 210 feet high. The Belle Fourche project in South Dakota will bring 80,000 acres under cultivation. The Palouse irrigation scheme covers 100,000 acres in Washington, capable, it is believed, of maintaining a population of 60,000 people.

The Salt River project in Arizona creates a lake eighteen miles long, four miles wide, and 275 feet deep. The dam of masonry which closes the canyon is 165 feet thick at the base. The top is wide enough to serve as a bridge and wagon road. One million dollars was spent in getting ready for the actual construction. When the water is ready for use 200,000 acres of desolation will be converted into orchards and fields of alfalfa. Other projects under construction are the Yuma, in California and Nevada, 85,000 acres; the Minidoka, Idaho, 60,000 acres; Huntley and the Milk River, Montana, 235,000 acres; the Fort Buford, Montana and North Dakota, 60,000 acres; the Hondo, New Mexico, 10,000 acres; the Bismarck, North Dakota, 15,000 acres; the Malheur, Oregon, 100,000 acres; the Klamath Falls, Oregon and California, 236,000 acres; and the Shoshone, Wyoming, 125,000 acres. In 1909 there were in all twenty-eight projects under way aggregating in area 1,910,000 acres. The United States may have seemed negligent of great possibilities, but the nation is young and is certainly making up rapidly for time lost in the past.

Irrigation presents many problems of its own. Much more water is needed than is popularly supposed. In addition to rainfall, the rice fields of Texas and Louisiana require to be flooded with a total of about two feet of water, not all at once, of course, but this amount of water must be supplied from time to time during the growing season. In the West the season for irrigation opens April 1st and closes September 15th. According to the reports of the United States Department of Agriculture, the principal crops require the following average supply of water:

In warm, rainless weather it is useless to sprinkle. The soil must be given a thorough soaking as often as necessary. Sometimes a dam bursts or a canal gives way. The water escapes. Crops parch and die before the breaks can be mended. The loss of water by leakage and seepage is great. Most canals are mere broad ditches dug through the land. Heavy clay soils are best for the purpose. Light ashy and sandy soils allow much of the water to soak away through their sides. Alkali soils have little containing power. Water carrying silt does most of its own work in packing the walls till they are comparatively watertight. In many cases it is necessary to plaster or cement the walls of the canals; but even then the loss of water through seepage in the smaller ditches is considerable. The loss by evaporation must be taken into account. At Phoenix, Arizona, the loss from this cause at the surface of a reservoir or canal is considered six feet five inches yearly; at Reno, Nevada, forty-two inches. The average loss from surface evaporation, that is to say, where standing or running water is exposed to the sun, is placed at from four to six and a half feet--this for the arid region of the Southwest. The loss in the Northwest may be half of this amount. All conditions considered, it may be said for the United States that from forty to sixty per cent of the water that starts finally reaches the field of the farmer.

Three methods of measuring water are in use. The miner's inch has been inherited from pioneer days. It is the amount of water that will flow through a hole an inch square, situated four inches below the surface. A farmer desiring to use this method of testing the amount of water he is getting dams up his ditch with a board made for the purpose. It is provided with a horizontal slot closed by a slide. When the water is dammed back until it stands four inches above the orifice the slide is pushed aside and is adjusted until the amount of water pouring through permits the water held back by the board to stand steadily at the four-inch level. The size of the orifice is then noted. If an inch slot is open ten inches, the ditch is supplying ten miner's inches of water. The second unit of measurement is the cubic foot per second. This method requires a water meter, an instrument that indicates the actual speed of the current. It is in favor with engineers. The third unit is the acre foot, that is to say, water enough to cover an acre of land one foot deep. Contracts may be made in either of the three ways.

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