A Drowned Empire 



10 o 



TYPE OF CONVEYOR DREDGE USED IN CHANNEL-DEEPENING 



least an additional 100,000 acres drained. 

 The Secretary points out with commend- 

 able pride that in the event that Congress 

 should require additional surveys or 

 drainage construction work performed, 

 his department has already two fully 

 equipped bureaus, the Geological Survey 

 and the Reclamation Service, ready at any 

 day to extend the drainage work they 

 are in reality already doing, and at the 

 same time he calls attention to the fact 

 that, considered in its entirety, the drain- 

 age problem is not as simple a one as 

 many suppose. It involves the handling 

 of one of the most powerful forces with 

 which man has to cope and is a matter of 

 the broadest practical engineering. 



The various phases of the problem may 

 be classified as follows : 



1. Farm drainage. 



2. Drainage and flood control. 



3. Drainage, flood control, and naviga- 

 tion. 



4. Tidal-flat drainage. 



The first is the simplest form of the 



problem — the draining of a farm or 

 group of farms into the nearest natural 

 run-off channel. 



The second and third are closely re- 

 lated and more complex, especially in the 

 determination of engineering measures 

 whereby disastrous floods may be pre- 

 vented and the water uniformly distrib- 

 uted over low-water seasons, so that 

 navigable stages in the rivers may be 

 maintained. 



The fourth comprises such lands as 

 may require protection from both streams 

 and the sea. 



The preliminary engineering require- 

 ments in every case are in nowise dif- 

 ferent from those governing the irriga- 

 tion of arid lands, the construction of 

 inland waterways, the prevention of 

 floods, the conservation of water, or any 

 other important water-supply develop- 

 ment. Such problems all involve engi- 

 neering and physical factors the control 

 of which may extend beyond the area 

 immediatelv under consideration. There- 



