The Mosquito Must Go 25 



About 20 per cent of the marsh is swept by the tide with 

 sufficient frequency as not to require mosquito drainage. Sub- 

 tracting the 20 per cent which will not require drainage, there 

 yet remains about 150,000 acres to be drained. At the estimated 

 acre cost of $6.00, about $900,000 should complete the initial 

 work of drainage. 



Salt-marsh Trenching Can Be Maintained For About 35 Cents 



Per Acre 



While the initial drainage is going on, and after it has been 

 completed, the problem of maintenance must be met. The ex- 

 perience on the marsh already drained for several years is vari- 

 able. The ditching systems on shut-in meadows with none or 

 only a slight tidal pull are costly, while those on the open 

 meadows with strong tidal outlets are cheap to maintain. When 

 the initial drainage has been completed there will be about 

 70,000,000 feet of ditching on the salt-marshes of the state. 

 About 20 per cent of this ditching will be served with such a 

 scouring tide that nothing but removal of occasional blockages 

 and shearing of over-growing sides will be necessary. Of the 

 balance, 56,000,000 feet, about one-third, or 18,666,666 feet, will 

 have to be cleaned each year. The average cost should not ex- 

 ceed one-third of a cent per linear foot, or about $63,000. To 

 this must, however, be added blockage removal, which may be 

 figured at about $800 per million feet. This adds $40,800 to the 

 previous sum, making $103,800, or about 35 cents per acre. 



Thirty-five cents an acre for maintenance is an average 

 figure for the salt-marsh as it lies and includes the area of the 

 20 per cent of marsh which does not require drainage. The av- 

 erage cost of the drained areas, exclusive of the areas not need- 

 ing drainage would, therefore, be somewhat greater than 35 

 cents. Furthermore, local conditions of marsh, labor and over- 

 sight will make a great difference in the cost. Without doubt 

 there are counties where, owing to the fact that the marsh is 

 open and has a good tidal suck, that labor is low-priced, and that 

 oversight is peculiarly efficient, the cost of maintenance will be 

 much less than 35 cents. Also, without doubt, there are counties 

 where, owing to less favorable conditions, the cost of mainten- 

 ance will be considerably higher. 



Furthermore, the development of power machinery for ditch 

 cleaning is bound to reduce cleaning costs. 



The state should materially assist in the establishment of 

 the initial drainage, but the present practice of local maintenance 

 should and doubtless will be continued until the marsh is elim- 

 inated as a possible mosquito breeder by agricultural, industrial 

 and urban development. 



