DRAINAGE OF JEFFERSON COUNTY, TEXAS. 17 
Although the Intercoastal Canal must be constructed before the 
reclamation of districts Nos. 24, 25, 2G, 27, 28, 29, 30, and 32 can be 
carried out accordmg to the plans presented herein, the cost of its 
construction is not charged to these districts. They are dependent 
upon the Intercoastal Canal for outlet, but since that waterway will 
be a benefit to the whole county as well as to adjoining counties and 
as it is possible that Federal appropriations will be made to help carry 
out this work no estimate is made of its cost. Should a different route 
be selected for the canal, the plans for the drainage of the above- 
named districts must be changed accordingly. 
CITIES AND TOWNS. 
The city of Beaumont is not included in any drainage district under 
the present arrangement. Some parts of the city will receive direct 
benefit when certain ditches of district No. 10 are constructed, but 
just what this benefit wiU be depends in part upon the location and 
construction of sewers. The greater part of Beaumont is drained into 
the Neches River and may be considered as a separate and inde- 
pendent drainage district. Port Arthur also is excluded from any 
of the enumerated drainage districts. It hes on very low ground and 
is affected by the same conditions as districts Nos. 16 and 17, but it 
has already built its own drainage system, including open ditches and 
pumping plant. The towns of Sabine and Sabine Pass and the half- 
mile strip of land connecting them, which have been filled in by suction 
dredges working in the Sabine Pass channel, are also excluded from 
any of the numbered districts. 
DRAINAGE DITCHES. 
CAPACITIES AND DIMENSIONS, 
The first step in designing the drains for each district to be drained 
wholly or partly by gravity was to determine the area that will be 
drained by each ditch, including the areas drained by each main 
ditch at the points where laterals or submains will enter. For each 
pumping district only the whole area and the area drained by each 
main ditch was determined. The rate of run-off from each such area 
was computed by Frescohi's formula, as previously described, to find 
the required capacity of each ditch. 
A profile along the route of each ditch was platted from the data on 
the map, and the grades of the ditch bottoms were determined from 
those profiles. The Chezy formula, V= C-yJRS, was used in comput- 
ing the sizes of the ditches, C being determined by Kutter's formula 
with 0.030 as the value of the roughness coefficient n. AU laterals 
in pumping districts were made of such size that they could be con- 
78948°— Bull. 193—15 3 
