12 BULLETIN 198, U. S. DEPARTMENT OF AGRICULTURE. 
MISSISSIPPI RIVER COMMISSION PLAN. 
The plan of the Mississippi River Commission, made in 1907, pro- 
vides merely for the diversion of Cypress Creek in order that the gap 
in the levee may be closed, and makes no provision for the further 
drainage of Desha County. The suggested course of the diversion 
is through Boggy Bayou, Boggy Lake, Clay Bayou, and Clay Bayou 
Wash into Macon Lake in Chicot County. The plan provides for 
2,300 second-feet of now at Boggy Cut-off and 3,150 second-feet 
above Macon Lake, requiring a channel of 60 to 80 feet in bottom 
width, with side slopes 1| horizontal to 1 vertical, flowing 11 to 11 1 
feet deep. 
The area drained by Cypress Creek is approximately 413 square 
miles, and that by Clay Bayou about 582 square miles. Using the 
drainage coefficients determined from figure 5, the capacity of the 
diversion channel should be 5,300 second-feet at Boggy Cut-off and 
7,050 second-feet at Macon Lake. In order to obtain a proper 
fall in the ditch and to give drainage to the upper district, it would be 
necessary to hold the high-water surface in this diversion channel 
3 to 4 feet below ground level. Since 15 to 16 feet is about the 
deepest economical excavation, the depth of How should be about 
12 feet. The required channel would then be 140 to 185 feet, 15 to 
16 feet deep, with 1 to 1 side slopes. There are two reasons for reject- 
ing this plan in favor of the ditch plan recommended : First, the cross 
section of the necessary channel is too great for the most economical 
construction; second, it will not serve effectively as the main drainage 
outlet for the district, principally because of the high banks along 
the larger tributaries. It has no advantage over the plan herein 
recommended. 
FLOODWAY PLAN. 
A system involving a combination of ditches and floodway was 
worked out in detail. This plan provides for carrying the drainage 
from Wells Bayou, Cypress Creek, and Oak Log Bayou through a 
floodway from Amos Bayou, in sec. 30, T. 10 S., R. 2 W., to Bayou 
Macon near McArthur. From here the channel of Bayou Macon was 
to be cleared as in the recommended plan. The drainage from a small 
area at the head of the Coon Bayou watershed would, under this plan, 
be diverted into the head of Bayou Macon. The remainder of the 
Coon Bayou drainage was to be carried under the floodway to the 
ditches in the eastern part of the district. 
The floodway would be a canal 90 to 200 feet in bottom width, 
excavated 5.5 to 23.7 feet deep, with levees on each side 4.5 to 13 feet 
high, except at the banks of Amos Bayou and Bayou Macon, where 
no levees would be required. The total earthwork for this floodway 
was computed to be 2,186,000 cubic yards, which is estimated would 
