172 PRACTICAL DRAINAGE 



work himself at odd times and does not have to pay for 

 materials makes it possible at times to put in an open 

 ditch, whereas a closed drain would be beyond his reach. 

 Among the disadvantages of the open drain are the facts 

 that the original cost does not represent the total outlay. 

 Every year, and often several times during the year, 

 open drains must be cleaned. The banks cave off or 

 other obstructions fall in and interfere with the effective- 



Fig. 22. Open Ditch Used to Carry Away the Drainage Water 

 from a Large Area. Covered Drains Empty into this Ditch. 



ness of the drain. Weeds growing on the banks and in 

 the bottom of the ditch are a constant source of annoy- 

 ance. Considerable land that could be cultivated if the 

 drain were covered is made useless by the open ditch, 

 which also cuts the land up into smaller fields causing 

 inconvenience in plowing and performing the other farm- 

 ing operations. Open ditches are always a source of danger 

 for farm animals that may fall in them and be injured. 

 These many disadvantages usually turn the preference 

 toward some form of covered drain, except in such cases 



