114 N. J. Mosquito Extermination Association 



run-off, the sources of the water, the nature and condition of the 

 soil, and amount of grade possible are all governing factors in desig- 

 nating the system of drainage which is most feasible. The greatest 

 amount of upland labor is spent in improving already existing condi- 

 tions rather than in draining areas that have never been drained 

 before. The obstructed stream, the grass-grown brook, the polluted 

 gutter, the partially drained swamp are far more prevalent especially 

 near habitations than are swamps and pools which man has never 

 before attempted to improve. Much work is also made necessary 

 because man in draining a particular spot often shows an utter dis- 

 regard for the drainage of the section as a whole. For instance, a 

 land development company in redeeming its own property will carry 

 the water from one side of the road to the other, or into a woods 

 where it is out of sight and then ''ostrich-like" think that the section 

 is drained. Engineers in charge of road construction also will insist 

 in locating culverts at the apparent grade of the stream instead of at 

 the true grade as determined by a complete survey of the areas to 

 be served by this culvert. "Culverts too high to allow complete 

 drainage" is a phrase which occurs over and over again on mosquito 

 inspector's reports of investigations made of breeding areas. And 

 by lowering culverts to proper grade much swampland can be com- 

 pletely drained and acres of mosquito breeding territory can be made 

 practically free from breeding. Old ditches which perhaps once 

 served a good purpose and were put in with the best intentions but 

 which have been abandoned or neglected and are congested and 

 choked are other heritages which descend to the energetic mosquito 

 inspector. But whether it be the old ditch to be cleaned, the par- 

 tially drained swamp to be finished, or the drainage of the hitherto 

 undrained swampland to be attempted, the proper method to be fol- 

 lowed can be decided upon only after a most complete and thorough 

 study of the conditions existing at each place under consideration. 



Open ditches are most often used because of the expense involved 

 in under drainage. For instance, if in draining an area it is found 

 necessary to clean out, trim and, re-grade a main stream or series of 

 ditches 8 or lo thousand feet in length, the impracticability of con- 

 sidering any other means than open drainage with the amount of 

 money available for mosquito control is at once apparent. However, 

 if the ditching under consideration involves a ditch of a few hundred- 

 feet or less and requires a deep cut or a cut through sandy or shift- 

 ing soil, tile drainage is the better and more economical means of 

 drainage in spite of the original cost. Often a nearby storm-sewer 



