148 



THE IRRIGATION AGE. 



acres one foot deep in a year. Now if we 

 call "the irrigating season " two hundred 

 days, then the number of acres to an inch 

 of water will by this mode of counting be 

 two hundred three hundred and sixty- 

 fifths of fourteen and a quarter (fH of 

 144). This will be about eight. But 

 counting by the year the number of acres 

 watered to the same depth would be about 

 fourteen and a quarter. So they will call 

 an acre foot if used in two hundred days 

 an inch to eight acres, but if used all the 

 year an inch to fourteen and a quarter. 

 Two acre feet would then be an inch to 

 four acres by the season, but estimating 

 the other way they would be three hundred 

 and sixty-five-two hundredths to four 

 acres (|^-| of 4) which equal about seven. 

 And in the same manner four acre feet 

 would be an inch to two acres by the 

 season and about three and a half by the 

 year. 



The only reliable way to find the amount 

 of water used is to take a tract of known 

 area and watch it while being irrigated so 

 as to get the percentage wasted at the 

 lower end. This will vary greatly, some 

 wasting even more than half the head 

 while others will have the lower end of 

 the tract thoroughly wet without wasting 

 one per cent. As this waste can be found 

 only by guess considerable care must be 

 used in comparing it with the head at the 

 upper end. As the owner knows little 

 more about what he is putting on than 

 the most intelligent Hottentot knows about 

 the rainfall that produces his banana crop, 

 you had better go to the office of the com- 

 pany and ask to see the water account of 

 that tract. If you satisfy the officers that 

 you are seeking information for a proper 

 purpose and will not use it in any other 

 way, you will seldom be refused a full in- 

 spection of the books. Sometimes it may 

 cost you the drinks and some cultivation 

 of the secretary or ditch-tender until he 

 finds you are a harmless person. 



Get the number of twenty- four hour 

 inches delivered to that tract during the 



irrigating season and also during the year. 

 Deducting the unnecessary waste you can 

 then reach the duty of water by both 

 methods. As a rule you will find the 

 duty of water much greater than the owner 

 himself would give it to you. But you 

 will find that some people, with exactly the 

 same amount of land, same soil, crops, 

 and all conditions, have ordered and paid 

 for twice as much as their neighbors. By 

 watching these tracts you will find this 

 difference due mainly to waste. But in 

 some it is due to using water more often 

 and letting it run longer. There are in- 

 dividual differences due often to the whim 

 of the irrigator and often to the desire to 

 experiment that cast much uncertainty on 

 the conclusions drawn even from the best 

 data. 



For alfalfa it is certainly safe to err in 

 using too much water than too little. So 

 with oranges and lemons, melons and 

 many other things. There is little danger 

 of using too much water for corn, but you 

 can easily use so much as to make the 

 yield of grain lighter instead of heavier. 

 Grapes to be used for wine, olives and 

 peaches and other fruits to be shipped 

 some distance to market will not be apt to 

 suffer if the error is on the side of too 

 little water. It would almost take a 

 treatise on agriculture and horticulture to 

 go through the list of all products in this 

 way, but the difference should be kept in 

 mind. 



The waste above referred to means 

 direct waste. Indirect waste is a great 

 item that reduces the duty of water. The 

 commonest form of this is using water in- 

 stead of the cultivator, already sufficiently 

 explained. It is a great absurdity to 

 charge against the duty of water the 

 amount poured on by one who will persist 

 in irrigating in the old Indian style. Yet 

 under many ditches fully one-half the 

 water is still wasted in that way. And 

 the resources of that section are deprecia- 

 ted by charging it against the duty of 

 water. 



