MARSH AND SWAMP. 5 



mingled with different classes of mineral matter which may have 

 been washed in from adjacent uplands or carried in by inundations 

 of the streams which flow through the majority of such swampy 

 areas. There is usually a considerable variation in the character 

 and texture of the material found in different parts of the same 

 area of Swamp. Usually, however, Marsh, Tidal marsh, and Swamp 

 are all marked by considerable accumulation within the surface soil 

 of organic matter in a partially decayed state. 



LIMITATIONS IN USE. 



In all cases the drainage of Marsh or Swamp is fundamentally 

 necessary to the utilization of such lands for agriculture. In the 

 case of Swamp clearing is also necessary. 



The drainage of any particular area of Swamp or Marsh constitutes 

 a separate engineering problem in itself. In the case of most of the 

 upland, fresh-water Marsh it is not difficult to find drainage ways 

 by which the surplus water may be removed. Frequently the mere 

 straightening of the channels of streams that flow sluggishly through 

 the area will serve to give a sufficient fall to remove the water from a 

 considerable proportion of the land. In other cases it is necessary to 

 remove barriers of earth or even of rock which have prevented the 

 cutting down of the stream channel and the accomplishment of 

 natural drainage. After the installation of the main drain, which 

 should follow approximately the natural drainage lines of the region, 

 it becomes necessary to drain still further the land through the 

 installation of open ditches and of tile underdrains. In many 

 instances it has been found necessary partially to accomplish the 

 drainage of the land by digging open ditches for the removal of the 

 surplus water before the installation of tile underdrains becomes 

 practicable. This arises from the fact that the removal of the water 

 from the surface soil and subsoil causes a considerable degree of 

 shrinkage of this material, and if the tile drain were installed before 

 a large part of this shrinkage had taken place, the tile lines would be 

 disturbed and the drainage would be interrupted. 



Wherever it is possible, in the drainage of Marsh, to cut through 

 the surface mucky material into a harder underlying subsoil material, 

 this preliminary precaution is not so necessary. 



In many instances the clearing of areas of Swamp costs from $20 to 

 $100 per acre in addition to the cost of drainage. 



The reclamation of Tidal marsh involves difficulties in the way of 

 engineering management that make such reclamation almost im- 

 possible to the individual upon a small scale. In consequence, every 

 project for which reclamation plans are to be made should be placed 

 in the hands of a competent engineer. It is wise to make a study of 

 the probable agricultural value of the land when reclaimed. This 



