8 BULLETIN 193, U. S. DEPARTMENT OF AGRICULTURE. 



to determine additional elevations and to check the work. Very 

 little time was given to locating property corners, and as most of the 

 land is divided into irregular tracts according to original surveys, 

 the cross levels were a,ll located with respect to mileposts or other 

 objects of known location along the railroads. The south end of the 

 county is subdivided into square miles which are numbered con- 

 secutively, but a great many of the corners are now obscured and 

 the level lines were located only approximately. All the streams 

 were meandered with compass and stadia, and levels were carried 

 on many of the meanders. A sufficient number of channel cross- 

 sections were taken to determine the sizes and capacities of the 

 streams. For determinmg the area drained into Jefferson County 

 from the west, lines of levels were projected west from the county 

 line at intervals of 2 miles and were carried beyond the divide between 

 the Trinity and Neches Rivers. Numerous bench marks were estab- 

 lished in all parts of the county, the locations, descriptions, and 

 elevations of which may be obtained upon request to the Chief of 

 Drainage Investigations, United States Department of Agriculture. 



A tract of about 70 square miles lying east of the Texas & New 

 Orleans Railroad (Sabine branch) was omitted from this survey 

 because the owners furnished a contour map of the tract, which was 

 adopted as correct after being checked by several lines of cross levels. 

 A number of land maps furnished by the county surveyor and right- 

 of-way maps supplied by the railroads were of great assistance in 

 making the survey. 



The map of Jefferson County (fig. 3, in pocket at end of bulletin) 

 was drawn to a scale of 3,000 feet to the inch, the outline being com- 

 piled from a War Department map of the Neches River, a Coast and 

 Geodetic Survey map of the Gulf shore, and the county surveyor's 

 maps of the west county boundary, and a right-of-way map of the 

 Southern Pacific Railroad. Upon this skeleton map were plotted all 

 the data obtained from the survey and from maps furnished by the 

 county surveyor, the railroads, and several irrigation and land com- 

 panies. The map shows also the complete system of dramagc im- 

 provements proposed for the county. It should be noted, however, 

 that drainage district No. 3 was organized and had begun construc- 

 tion before the project was undertaken, and the plans shown for 

 that district are not the work of Drainage Investigations. 



THE DRAINAGE PROBLEM. 



As in most other counties of Texas bordering on the Gulf, the 

 great areas of undrained and unimproved lands in Jefferson Coim.ty 

 present several problems in their reclamation. The low-ljdng 

 tracts of salt mai"sh adjacent to the Gulf which are subject to over- 



