Miscellaneous. 



272 



[Srpt. 1906. 



As much as 1,250 cu. sees havejbeen diverted into the various canals during the 

 month of March, when the flow is usually most plentiful, and the supply fell as low as 

 120 cu. sees in the month of July, 1900, during the whole of which year, one of unusual 

 drought, it did not average more than 400 cu. sees. In spite of this deficiency no less 

 than 113,000 acres of crops were raised in that year, while the greatest area irrigable 

 may be taken as 150,000 acres. The actual quantity of water used per acre of crops 

 was 2*78 acre feet in 1902 (including canal losses and rainfall), while the amount 

 usually taken is betweeu 3 and 4 acre feet per acre of crops raised. These figures 

 may be compared with the consumption per acre of not less than 12*75 acre feet (not 

 including rainfall) used under the Walawe Channels near Hambantota in 1904. 



The water from the salt river is distributed to each of the main channels 

 according to priority of right, the oldest channel being entitled to full supply while it 

 is available, and the most recently constructed channel being the first to be deprived 

 of water in times of tight supply. The actual quantity of water distributed to each 

 of the various main channels is apportioned from day to day by a Commissioner 

 specially appointed, and the quantity so apportioned is taken charge of below the 

 gauge at the head of each canal by the various canal officers who attend to its 

 further distribution. 



The water is distributed from the main canals to the various users in propor- 

 tion to the " water tight " or share of it actually owned by the user. In some eases 

 the shares carry priority of right, but as a broad rule they entitle the holder to a 

 certain proportion of the water only. 



The actual division of the water from the main channels is effected by smaller 

 channels known as laterals, near the beginning of which there is— sometimes at least — 

 a gauge for the measurement of the water. Where these laterals supply the land of 

 one owner they are constructed and maintained by the owner. "Where they supply 

 several owners they may have been constructed and maintained by the canal 

 company, but are more generally constructed and maintained by the several owners 

 in common. 



Each owner is assessed for the maintenance of that portion of the main canal 

 above his head gate only, and to this has to be added his share of the maintenance of 

 his lateral if he owns it in common with others, or it' it was constructed by the canal 

 company. As a result of these arrangements the actual cost of water is greater near 

 the tail than at the head of a canal. 



Recently the plan has been adopted of discharging the full supply of the 

 main canal, or a definite proportion of it, into each lateral for a definite period of 

 time. Where the lateral is the property of several parties the further distribution 

 of the water is left to the parties themselves. 



As an example of this method a certain farmer was entitled to all the water 

 passed into the lateral from which he obtained his supply for (50 hours from 6 p.m. 

 on each of the following days : — 15th and 26th July, 6th, 17th and 28th August, 8th, 19th, 

 and 30th September, 11th and 22nd October. The area irrigated was 50 acres, and 

 from the figures he got water for 24 days out of every eleven. 



Method of Irrigation.— Now with regard to the actual distribution of the 

 water in the fields themselves. It is here that excessive waste of water takes place 

 in all irrigation systems, and it is just here that the system in use round Phoenix 

 appears to be most efficient. 



From his lateral, or from another smaller lateral, if he holds his main lateral 

 in common with others, the farmer distributes the water to his fields by a system of 

 field laterals or small ditches taking off from the larger lateral more or less at right 

 angles to it at distances of from 75 to 150 feet apart in grain and 150 to 200 feet 

 apart in pasture land. These field laterals are frequently set off with an Engineer's 

 level to a gradient of from i to \\ inches per rood, or say from 1 in 300 to 1 in 100. 



