121 



MOSQUITO ERA DIC A TION 



suitable place where it will remain filled with water for the stock 

 to drink. 



While recleaning of open ditches along the lines described will 

 be required from time to time during the mosquito season, it is a 

 good plan to get all such ditches in shape early in the season 

 before the first new broods of mosquitoes appear. 



MAINTENANCE COSTS 



Maintenance costs vary considerably with local conditions. In 

 areas where weeds grow rapidly, they probably will prove the 



%4**&H 





%■ 



Fig. 83. — Cleaning out an old, clogged up ditch by hand. 



most troublesome factor. In some places, the writer has found 

 it necessary to remove these growths every month or so; this 

 runs into a large amount of money in a season on a large project. 

 Again, heavy rains, resulting in rapid run-offs, sometimes ruin the 

 grade of miles of ditches; sand and mud will be deposited at many 

 places, while deep holes will be cut into the banks and bottom at 

 others. 



During 1918, on a job with which the writer was connected, 



