534 TROI'IL.IL HYGIRXE. SAX IT ATIOX , HTC. 



(3) I>\ ((b.siriiciccl dr.iina.ijr rcsiiltiii}^^ Irom railway fmbaiikmenls, 

 excavations, &r., resuliin.tr from such cunsiruriional works. Also by 

 sand pits and clay holes. 



(4) 15v the backwater from obstructed rivers, blocking up the house 

 drains by its refu.se. 



(5) Bv sullaj^e water when a water .system has been provided with- 

 out the nece.s.sary drainage for waste water. 



(6) At (tr near the irregularities of the earth's surface, as at the 

 f(X)t of hills and low-lyinj^ country. Such |)Iaces are often flooded 

 for months after the rains. 



(7) Hv tile effects of lar<^e-scale irrijj^alions, unaccompanied b\ 

 efticient drainaj^e. To correct this latter fault the Indian Sanitary 

 jx)wers have laid down the following regulations: — 



(i) The irrigation canals to be constructed along the line of the 

 watershed. 



(2) The smaller canals to be so constructed as not to be carried 

 across tiie natural lines of drainage. 



(3) Drainage cuts to be constructed along the natural lines of 

 outfall. 



(4) The supply of water to be limited lo the amount required, 

 and to the particular time needed to secure the success of the crops. 



The Government of (he Soudan have introduced the following 

 regulations in regard to irrigation : — 



(i) Irrigation channels should be constructed on a higher level 

 than the surrounding ground, so that when :he flow of water in them 

 ceases they may drain dry. 



(2) Thev should be constructed of such material, and in such a 

 manner as to prevent leakage. 



(3) Their banks and beds should be kept in good repair and the 

 beds even to |>revent the formation of pools. 



(4) " Dead ends " of irrigation < hannels should be reduced to liie 

 smallest size compatible with efficiency, so that water will not stagnate 

 in them. 



(5) \ egetation should be pericxlically cleared out of the channels. 



(6) Sluices should be ccjnslructed so that there is no leakage to 

 form stagnant puddles. 



(7) Where possible fish should be introduced, and kept in the 

 main channels to destroy larv.e. 



(8) Lands where water is apt to stand should have proper surface 

 drains. 



(()) Crops, such as sugar cane, rice, or others, which require to 

 stand in water, should not be grown within a mile of any town or 

 village. 



