226 IRRIGATION INVESTIGATIONS IN CALIFORNIA. 



CHOWCHILLA CREEK. 



Chowchilla Creek is similar in origin and characteristics to Fi'esno River, already 

 described. It has a drainage area of 268 square miles, and, like the Fresno, is sub- 

 ject to sudden freshets in the rainy season. Records have given it a mean monthly 

 flow as high as 1,608 cubic feet per second, but its average during the months from 

 December to July, inclusive, is far below that amount, being approximatelj' 150 cubic 

 feet per second. The months from February to June, inclusive, furnish the greatest 

 flow, averaging 333 cubic feet per second; but the months from July to October, 

 inclusive, ordinarily afl^ord little or no water. 



The only irrigation systems on Chowchilla Creek are those of the Sierra Vista 

 Vineyard Compan}' and the Bliss ditches. By means of dams across the bed of the 

 creek they utilize the flow of the stream to irrigate some 6.000 or 8,000 acres of land 

 lying on either side of the stream, upon which vineyards, fruit trees, alfalfa, and 

 pasture lands are cultivated or improved. The area irrigated in any one year is 

 largely dependent upon the rainfall and the resulting water supply in the creek. The 

 irrigated area might be largely increased bj' multiplying the number of dams and 

 thus establishing a series of impounding reservoirs in the b6d of the stream. As it 

 is, during freshets, much water must be turned aside into the beds of Berenda and Ash 

 sloughs in order to avoid the destruction of the dams. Such new impounding dams 

 should have stability sufiicient to resist destruction by sudden floods and freshets. 

 There are, also, one or two excellent reservoir sites in the mountains above Buchanan, 

 where large quantities of water might be stored. 



The valley lands adjacent to the San Joaquin and its l)ranches, now being irri- 

 gated by existing canals, approximate 120,000 acres in cereals, fruits, and alfalfa, 

 and the area of wild grass lands which are overflowed by the flood waters of the river 

 is full}' double this amount. 



ESTIMATE OF TOTAL AREA OF LAND WHICH MIGHT BE IRRIGATED FROM 

 SAN JOAaUIN AND FRESNO RIVERS AND CHOWCHILLA CREEK. 



In making this estimate I proceed on the assumption that the duty of water in 

 this region, the vallej' trough, is approximately 160 acres per cubic foot per second. 

 I assume this dutj' because no positive and definite information has been available as 

 to the exact duty of water on the different irrigated areas investigated by me, but the 

 general consensus of opinion among canal owners, ranch owners, and canal superin- 

 tendents is that the above is a fair approximate average of the dutj' of water. 



I find from Hall's tables of flow of water in San Joaquin River, established by 

 gagings from 1878 to 1884, inclusive, that the average number of cubic feet per 

 second for the period from November to January, inclusive, is 750, which, upon the 

 assumption that a cubic foot per second will irrigate 160 acres of land, would, during 

 this period, properlj' irrigate 120,000 acres of land if all the water flowing were avail- 

 able for irrigation. In the same way the average flow for the period from February 

 to April, inclusive, being 2,462 cubic feet per second, would .serve 393,920 acres; in 

 the period from May to June, inclusive, the mean of about 7,458 cubic feet per 

 second would irrigate 1,193,280 acres, and during August to October, inclusive, tha 

 808 cubic feet per second, average mean flow, would irrigate 129,280 acres of land. 



