392 



Irrigation and Drainage 



monly the practice in humid climates, that two crops 

 are being grown at the same time upon the land, and 

 that under these conditions more water is demanded. 

 The roots of shrubs and trees are more deeply placed 

 in the subsoil than are most of those which feed the 

 lawn grass, and hence all rains too light to over- 

 saturate the surface 6 inches are practically secured 

 by the grass, and since to maintain a good lawn 



Fig. 120. Plan of basin flooding in garden irrigation. 



requires more water than ordinarily falls as rain, 

 even in quite humid climates, it follows that in all 

 public parks, cemeteries and ornamental grounds about 

 homes, there should be provided an abundant supply 

 of water for thorough irrigation. 



In watering lawns and parks, so much water is 

 demanded that it ought usually to be applied by 

 some flooding system rather than by spraying, as 



