Nov. 5, 1017 
Run-off from Drained Prairie Lands 
279 
tion of about 30 per cent in the average frequency of storms could be 
made safely and that the resulting figure would be the proper one for 
use. If the character of operations that are to be conducted on the land 
of a given district is known, a decision can then be made as to the heaviest 
storm for which provision must be made. On a district where staple 
crops are to be raised it would be economical to allow a certain amount 
of flooding oftener than would be advisable on land where high-priced 
truck crops are to be raised, while in residence districts it would be very 
desirable to prevent all surface flooding. In addition to the damage to 
crops due to flooding, there are other factors to be considered, such as 
inconvenience to residents and the possible depressing influence on land 
values of floodings occurring even at infrequent intervals. 
