32 BULLETIN 193^ U. S. DEPARTMENT 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 foUowuig extraordinarily heavy 
storms. The ditches are so arranged that few points will be more 
than a quarter of a mile from a lateral. The design provides con- 
vement 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 coimty, and at a later date when the 
lands are put under thorough cultivation additional ditches will 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 will not carry all 
this excess water 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 mone}^ 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 drainage 
may be measured by the increase in land values which it produces. 
If the land is as fertile in Jefferson County, Tex., as in some other 
localities along the Gulf coast, which can easily be determined, the 
net increase in crop values w^hen 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. Farming 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. Localities where malaria exists will be benefited through 
the removal of stagnant pools that are the breeding places for mos-. 
quitoes which spread this disease. Drainage is also necessary if the 
good highway system, of which Jefferson County is proud, is to be 
economically maintained and extended. 
