run to waste. The cycle of dry years just past and the introduction of new crops have called public attention to the urgent need of supplementing the scant rainfall by irrigation. The present report is based on investigations undertaken to aid in the development of the water supply of this region. In early days all the upper Salinas Valley was given over to stock raising, the upper valley and mesa lands supporting vast herds. In the early seventies, when the railroad was built south to Soledad, a gradual change took place and wheat farming was begun in the valley. At the present time practically all the high valley land is used for raising wheat and barley, while the uplands or mesas, with the mountain slopes and small valleys, are still given over to stock raising. Grazing is and always will be an important industry. Pl. II shows the location of the irrigated and irrigable lands and the proposed storage reservoirs and canals in the Salinas Valley. It is estimated that there are 65,000 acres of irrigable land lying between the headworks of the Salinas canal and the ocean. Of this amount about 20,300 acres are irrigated by various ditches and pumping plants, leaving a balance of 44,700 acres of irrigable land to be provided for. The principal crops irrigated are sugar beets, alfalfa, vegetables, and grain. Land on which sugar beets are raised is irrigated during the winter or early spring, usually but once, about 14 acre-feet being run over the field. The amount of water used of course varies with difference in the porosity of soil, but 1 acre-feet is a close average. This is in addition to the rainfall. Sugar beets are not irrigated after planting, but depend entirely upon one irrigation and the rainfall. Alfalfa is usually irrigated twice during the summer, about 1 acrefeet being used for each irrigation, or a total of 3 acre-feet a year. Alfalfa is ordinarily cut four and sometimes five times a year. Land on which potatoes are raised is irrigated once, in early spring, before planting, about 1 acre-feet being used. Grain is irrigated once, in April or May, about 1 acre-feet being used. The cost of irrigation from canals is about $1.50 per acre-foot, including profits to the canal companies. Irrigation by pumping is necessarily more expensive, the average cost, not including profits, being about $2.50 per irrigation, or $1.67 per acre-foot. CANALS. The following is a brief description of the irrigation works now in operation in the Salinas Valley. The Salinas canal was constructed in 1896 and 1897. Water is diverted from Salinas River to this canal by means of a temporary dam near the north line of San Benito rancho, south of Kings City (Pl. II). The canal is 30 feet wide on the bottom, 40 feet wide on top, and was constructed to carry 5 feet of water. The grade is very light, 6 inches per mile, and the total length of the canal is about 9 miles. This canal was designed to divert water for winter and spring irrigation only, and now irrigates about 3,500 acres of land near Kings City, the principal crop being sugar beets and barley. The San Lorenzo canal was constructed in 1896. Water is diverted from San Lorenzo Creek by means of a temporary dam of gravel at the mouth of the canyon, one-half mile below the Mathews dam site. (Pl. II). The canal is 20 feet wide on the bottom, 30 feet wide on top, and was designed to carry 5 feet of water. The grade is 5 feet per mile, and the total length of the canal about 8 miles. This canal was designed for winter use only, and takes the flood water and winter flow from San Lorenzo Creek, which is practically a dry stream in the summer. The land irrigated is what is termed the San Lorenzo Creek bottom, and the amount irrigated each year has varied greatly, for since the construction of the canal there have been years of very scant rainfall. Perhaps 800 acres a year would cover the service of this canal. The Arroyo Seco canal No. 1 diverts flood water from the Arroyo Seco at the south line of lot 1 of the Arroyo Seco rancho (Pl. II). It was constructed in 1897. The canal is 25 feet wide on the bottom, 35 feet wide on top, and was designed to carry 5 feet of water. grade is 5 feet per mile and the length is about 4 miles. This canal irrigates about 300 acres of land a year on the north half of the Arroyo Seco rancho. Arroyo Seco canal No. 2 is owned by the Arroyo Seco Improvement Company. It was constructed in 1898. Water is diverted to this canal by a temporary dam of gravel at the mouth of the canyon of the Arroyo Seco, at the south line of the Arroyo Seco rancho (Pl. II). The canal is 17 feet wide on the bottom, 27 feet wide on top, and was constructed to carry 5 feet of water. The grade is 1 foot per mile and the total length about 4 miles. This canal irrigates about 4,000 acres of land each year on the south half of the Arroyo Seco rancho and on the Espinosa tract. Arroyo Seco canal No. 3 was constructed by the Spreckels Sugar Company in 1901 and 1902. Water is diverted to this canal from the Arroyo Seco by a temporary dam about one-half mile below the head of canal No. 2 (Pl. II). The canal is 20 feet wide on the bottom, 38 feet wide on top, and was constructed to carry 4 feet of water. The grade is 5 feet per mile, and the length is 14 miles. It irrigates 2,000 acres of land on the Soledad rancho." The Gonzales Water Company's canal was constructed in 1899 at a cost of $18,375 for construction of canal and right of way. The main canal is 7 miles long and diverts water from Salinas River by a wing dam of sand and brush about 4 miles south of the town of Gonzales (Pl. II). The river at this point flows throughout the year. The canal is 16 feet wide on the bottom, 32 feet wide on top, a Information furnished by the Spreckels Sugar Company. and has a grade of 1 foot per mile. About 2,700 acres of land are irrigated from this canal, principally grain land, but during the last summer somewhat over 500 acres have been irrigrated for alfalfa, beets, and beans. The land has proved to be well adapted to irrigation, being well drained and fertile. Good crops have been obtained when all else around was a failure." The Brandenstein ditch (now abandoned) diverted water from Salinas River in sec. 10, T. 23 S., R. 10 E., M. D. M., and irrigated land on the San Bernardino rancho, southeast of San Ardo. The survey was made for a canal 50 feet wide with a depth of 3 feet of water, and with a grade of 2 feet per mile. The main canal is about 6 miles long, and from 8 to 10 miles of lateral ditches have been constructed. No information is available as to the amount of water actually used or the exact location of the canals, so no attempt has been made to delineate them on the maps." PUMPING PLANTS. Considerable water is pumped for irrigation at several points in the Salinas Valley. At the Spreckels Sugar Company's ranch No. 1, at the sugar factory, 4 miles south of Salinas (Pl. II), about 3,000 acres are irrigated, the waste water from the factory being utilized. The pump is an 18-inch Byron-Jackson centrifugal, directly connected with a General Electric 400-horsepower motor, driven from the factory generator. The average lift is 25 feet; the total average lift, including friction in pipe, 50 feet. The length of pipe is 4 miles; the diameters, 30, 32, and 34 inches. The general requirements of irrigation demand 20 inches in depth of water per annum. The pump can also take water directly from Salinas River for irrigation at any time. Water is spread by a system of permanent checks. The average size of the ditches is 3 feet on bottom, 12 feet on top, and 34 feet deep. The Spreckels Sugar Company also has a pumping plant on the Willoughby tract, near Spence station, on the right bank of Salinas River (Pl. II). The plant consists of one 20-inch Krugh centrifugal pump, belted to an Atlas compound engine. The pump takes water from Salinas River to irrigate 500 acres. The capacity of pump is 6,000 to 10,000 gallons per minute, with an average lift of 23 feet. The average area irrigated is 350 acres on alternate years. The average cost of pumping water is $2 per acre, or $1.20 per acre-foot, running daytime only. The consumption of fuel is one-third cord of wood per acre irrigated. At the Spreckels Sugar Company's ranch No. 2-the Soledad rancho (Pl. II), opposite Soledad-about 500 acres are irrigated by water pumped from Salinas River. The pumping plant consists of one 20-inch Krugh centrifugal pump, belted to an 18 by 24 inch Atlas a Information furnished by Dr. A. Gonzales, president Gonzales Water Company. |