CYPRESS CREEK DRAINAGE DISTRICT, ARKANSAS. 15 
into Lost Chain Creek and thence into Bayou Macon in sec. 32, 
T. 13 S., R. 2 W. 
Although natural channels have been utilized wherever possible, 
it was frequently found advisable to locate the ditches entirely inde- 
pendent of existing streams, on account of the high banks, poor 
alignment, and cost of clearing of the latter. 
Laterals are provided in sufficient number and of such depth as to 
afford good drainage to the areas lying back from the mains when the 
necessary field ditches are constructed. 
DETAILS OF DITCHES. 
All of the proposed work is shown in figure 3. Profiles of ditches 
Nos. 13, 18, 19, 43, 66, 67, 76, and 81 are shown in figure 6 (in pocket 
at end of bulletin) . Tables of hydraulic and construction data for each 
ditch are on file with Drainage Investigations, United States Depart- 
ment of Agriculture. 
Kutter's formula has been used in all cases in computing the capaci- 
ties of the ditches. A roughness coefficient of 0.025 has been used 
for all artificial channels and of 0.035 for existing channels that are to 
be cleared. In ditch No. 19, from station 949 to station 976, where 
the channel of Coon Bayou is to be cleared and grubbed, a coefficient 
of 0.030 was used. Where practicable, the proposed high-water 
lines in the channels are placed 1 to 2 feet below the surface of the 
ground. The grades are made as uniform as practicable, and at 
points where the grade is decreased, thereby necessitating larger ditch 
sections, the depth of flow is increased rather than the bottom width, 
in order to avoid great changes in velocity. 
The minimum ditch planned has a bottom width of 14 feet, side 
slopes \ to 1, and depth of flow 6 feet. This is the smallest that can 
be constructed economically by a floating dredge in timbered lands. 
The width of berm is independent of the width of the ditch, but varies 
with the depth of excavation. For cuts of 10 feet or less a berm of 
10 feet is planned; for cuts of 10 to 15 feet a berm of 12 feet; and 
for cuts deeper than 15 feet a berm of 15 feet is proposed. 
In existing channels where clearing is the only improvement 
needed all timber and underbrush should be cut and all debris removed. 
No stumps should project more than 18 inches above the ground. A 
short section of ditch No. 19, in Coon Bayou, will need to be cleared 
and grubbed in order that it may have the required capacity; in this 
section all stumps should be removed or cut level with the ground in 
addition to the ordinary clearing. 
The widths required as right of way for the ditches were computed 
by taking three and one-half times the top width of the ditch plus the 
width of both berms. The cost of right of way was estimated at $20 
per acre. No allowance was made for this cost where the ditches fol- 
low present channels. - 
