Proceedings of Sixth Annual Meeting 



117 



In a few limited localities it has been found more practicable 

 to fence the tide out than to cut the large outlets necessary to get 

 rid of the tide water. But even in such cases, unless the drainage 

 systems are pumped dry, it has been found necessary to find a 

 way to introduce and distribute killifish throug'hout the ditches. 



The unit of the drainage system for salt miarsh mosquito sup- 

 pression which 16 years' experience has shown to be best, is a 

 ditch 10 inches wide by 30 inches deep, with straight, smooth 

 sides and an even bottom. These unit ditches are led into natural 

 creeks wherever such action is possible, but run into a specially 

 cut outlet ditch when natural outlets are not obtainable. The 

 deeper salt holes are drained by spurs from the nearest unit ditch. 

 The shallow and small holes are filled with sod taken from the 

 ditching. The distance between drainage ditches varies from 100 

 to 400 feet, depending upon the porosity of the particular salt 

 marsh. Most marshes require the drains 150 feet apart. 



The trenches described in the preceding paragraph can be, and 

 often are, dug with ordinary garden spades. It is usually more 

 economical, however, to use special tools which have been perfected 

 for this type of work during the last 12 years. There are at the 

 present time in use on the salt marshes of New York and New 

 Jersey, one type of one-man spade, two types of two-man spades, 

 a three-man spade and a power ditcher. The power ditcher, under 

 some conditions, is the most efficient of these tools. With this 

 machine, 5,000 lineal feet of 10 inch by 30 inch ditching can be cut 

 in a day of ten hours. 



An average of about 300 linear feet of unit ditching and spurring 

 is required for one acre. The cost of cutting varies from 1 to 3 

 cents per foot, depending upon the price of labor and the type of 

 machinery used. With funds available for continuous drainage 

 over large areas, the salt marsh can be satisfactorily drained for 

 about $5.00 an acre. 



The total area of salt marsh is about 296,000 acres. Basing the 

 calculations on the estimated degree of completion of salt marsh 

 drainage in each county, drainage enough to cover about 13,374 

 acres, not to mention dikes, tide gates and pumps, is needed in 

 Hudson, Bergen, Union, Middlesex and Monmouth counties. To 

 this must be added 12,000 acres in Ocean, nearly 10,000 in Bur- 

 lington, about 20,000 in Atlantic, about 45,000 in Cape May, 52,661 



