146 IRRIGATION FARMING. 



governing the rights of appropriation from public 

 streams. 



The California Standard. — The most economic 

 users of water, in America at least, are the Californi- 

 ans, as their necessities are reduced on account of a 

 limited water-supply. At Riverside they use an inch 

 of water to five acres, and some an inch to three acres. 

 But this is because they charge to the land all the 

 waste on the main ditch and because they use thirty 

 per cent, of the water in July and August, when it is 

 the lowest. But this is no test of the duty of water ; 

 the amount adlually delivered on the land should be 

 taken. What they adlually use for ten acres at River- 

 side, Redlands, etc., is a twenty-inch head of three 

 days' run five times in the year, equal to 300 inches 

 for one day, or one inch steady run for 300 days. As 

 an inch is the equivalent of 365 inches one day, or one 

 inch for 365 days, 300 inches for one day equals an 

 inch to twelve acres. Many use even less than this, 

 running the water only two or two and one-half days 

 at a time. Others use more head, but it rarely exceeds 

 twenty-four inches for three days and five times a year, 

 which would be seventy-two multiplied by five, or 360 

 inches, a little less than a full inch for a year for ten 

 acres. In summing up, we may say that the duty of 

 water in Southern California may be put at an average 

 of one inch to eight acres, and the cost of water at a 

 first charge of $35 to |6o an acre for the right, and a 

 further charge of $1.50 to $2.50 an acre per annum 

 for the water whether used or not. 



Evaporation. — Throughout the arid region of the 

 United States the conditions which determine the 



