State Agricultural Society. 311 



days and seven nights. The canal can fill, at the same time, six of the 

 primary ditches, so that in seven days fourteen thousand four hundred 

 acres can bo covered with three inches of water, only six of the prima- 

 ries being full at a time. And in twenty-six days three inches of water 

 may be put over the whole amount of the land, namely, fifty-three thou- 

 sand six hundred acres. If the water is used only for fourteen hours 

 for each day, the time necessary to go over all the land with three 

 inches of water will be forty-five days. 



Under our hypothesis, in order to irrigate twenty-four hundred acres, 

 we must build one mile of main canal and five miles of primary ditches. 

 Placing the excavation at thirty cents per cubic yard, we find the cost 

 per acre to be about five dollars. The section of the main canal will 

 diminish toward its lower end, but to be on the safe side so far as cost is 

 concerned, we keep it of uniform size. 



, the price op excavation 



May be somewhat in excess of its actual cost, in some places, but inas- 

 much as in it are included all incidental and contingent expenses, we 

 believe it is not far from correct. We have omitted from this calcula- 

 tion all estimates of the irregularity of the ground, by reason of which 

 the amount of excavation may be considerably increased; all expense 

 due to the fact that generally one or several miles of canal have to be 

 made at its head before the water is high enough relatively to the adjoin- 

 ing land to irrigate it, and we do not include the cost of a dam, which, 

 generally, will be indispensable. Neither do we include the cost of 

 headworks, or of the bridges and sluices, which will be required, or the 

 measures that may be necessary to pass the drainage off the country, 

 into, over, or under the canal. We do not estimate for these points, for 

 the reason that no estimate can be made, the circumstances in no two 

 cases being the same. 



TEN DOLLARS PER ACRE TO IRRIGATE THE VALLEYS. 



Speaking generally, we are of the opinion that the omitted points will 

 cost as much as the excavation, and hence that the rate per acre just 

 given should be doubled. This brings us to the conclusion that it will 

 cost about ten dollars per acre to irrigate these valleys. 



It is, however, to be remarked, that large portions of the eastern side 

 of the San Joaquin Valley are underlaid, two or three feet from the sur- 

 face, by a hard stratum, which it will be necessary to blast, or if not 

 blasted, the canals must be very shallow. This fact leads us to believe 

 that the cost per acre in these sections will be increased twenty-five to 

 thirty per cent above the estimate already given. 



THE IRRIGATION OP THE FOOTHILLS 



Will, of course, cost more. Here the problem will be more similar to 

 that presented in other countries. So far as we are able to judge from 

 descriptions* given by writers, we are inclined to believe that the physi- 

 cal|conditions in these valleys are exceptionally favorable to irrigation. 

 This fact accounts, in a great measure, for the smallness of our esti- 

 mates, as compared with the actual cost of canals in Spain, for instance, 

 where the price of labor is so much cheaper than it is in California. 

 A further reason for this difference lies in the character of the con- 



