32 BULLETIN 193, U. S. DEPAETMBNT OF AGEICULTUKE. 



CONCLUSION. 



SUFFICIENCY OF THE DRAINAGE PLAN. 



The various improvements for each gravity district in Jefferson 

 County have been planned to provide every part of such districts 

 with sufficient outlet to insure against injury from excess of water 

 except during and immediately following extraordinarily heavy 

 storms. The ditches are so arranged that few points wall be more 

 than a quarter of a mile from a lateral. The design provides con- 

 venient and adequate outlets for tile drains or field ditches that 

 landowners may "wish to install. 



In the pumping districts the ditches are planned 1 mile apart to 

 serve the present needs of the county, and at a later date when the 

 lands are put under thorough cultivation additional ditches wdll be 

 needed to give complete drainage. The pumping plant for each 

 district was designed to remove the excess water promptly after 

 heavy rainstorms, to a depth of 4 feet below the ground surface at 

 the site of the pumping plant, when the entire district has been 

 thoroughly ditched, although canals 1 mile apart mil not carry all 

 tliis excess w^ater promptly to the pumps and therefore the drainage 

 will be much slower under the present plan than when the addi- 

 tional ditches and field laterals shall have been constructed. 



VALUE OF DRAINAGE IN JEFFERSON COUNTY. 



The money value of drainage is not easily measured, but the cost 

 of this work is a permanent investment which must be added to the 

 cost of the land if the proper returns are to be obtained from the 

 first investment. As only 10 per cent of the area is timbered, the 

 cost of clearing will be comparatively small. The worth of dramage 

 may be measured by the increase in land values wliich it produces. 

 If the land is as fertile in Jefferson County, Tex., as in some other 

 localities along the Gulf coast, w^hich can easily be deternmied, the 

 net increase m crop values when the land has been reclaimed may be 

 expected to yield very profitable returns upon the cost of purchase, 

 drainage, and any other measures necessary to put the land into 

 cultivation. Farmmg operations may be conducted more economi- 

 cally on drained than undrained land. Rice growing is the principal 

 industry of the county, and this requires drainage as well as irriga- 

 tion. Drainage is also insurance against loss of crops by excessive 

 wetness. Locahties where malaria exists will be benefited through 

 the removal of stagnant pools that are the breeding places for mos- 

 quitoes which spread this cUsease. Drainage is also necessary if the 

 good highway system, of which Jefferson County is proud, is to be 

 economicallv maintained and extended. 



