DKAINAGE OF BLACK AND BOGGY SWAMPS, S. C. 13 
The estimate of the amount of excavation for this ditch was com- 
puted in 2 ; 000-foot sections from the profile data secured. Six high- 
way bridges will be required, three of 30 feet span, and one each of 
15, 35, and 45 feet span. 
Beaver Dam Branch No. 1 is the largest tributary of Boggy Swamp, 
being about 8 miles long. It has numerous tributaries, in which small 
ditches should be constructed. The swamp along this branch is very 
narrow, except the portion southwest of Scotia, which is about 2,000 
feet wide, and formerly was cultivated in rice. The upper portion 
of the drainage area is rolling, and is practically all under cultivation 
except in the several bays. The lower part is much flatter and con- 
tains large areas of flat woods which are badly in need of drainage. 
The proposed improvements on Beaver Dam Branch No. 1 consist 
of a handmade ditch for the upper 7,550 feet, above the Seaboard 
|. Air Line Railway, and a minimum dredge ditch from the railroad 
down to Boggy Swamp, a total length of 38,500 feet. The fall is 37 
feet in 7.3 miles, or 5 feet to the mile, but very little of it occurs in 
the upper mile. Two 30-foot highway bridges will be required. 
Beaver Dam Branch No. 2 has a swamp that varies much in width, 
from 100 feet in some places to a half-mile in others. The watershed 
area comprises mostly good rolling land, much of which is under cul- 
tivation at the present time, although there is a large area of flat 
bays and ponds covered with a thick growth of timber. The pro- 
posed improvements consist of a minimum dredge ditch for its whole 
length of 25,420 feet, except the upper mile which should be a hand- 
made ditch. The fall is about 35 feet in 5 miles. One 30-foot bridge 
will be required. 
Manigault Branch heads in a series of flats and ponds between 
Shirley and Scotia, and joins Boggy Swamp where the swamps are sub- 
ject to overflow from the Savannah River. For the first 2 miles, 
in the flats and ponds, the swamp is about one-fourth mile wide, but 
it narrows below the Augusta Road to about 100 feet, widening out 
again lower down to about 500 feet. The watershed area of Mani- 
gault Branch is for the most part fairly flat, with large stretches of 
flat pine woods and a small percentage of land under cultivation. 
The proposed improvements on this branch consist of a .minimum 
dredge ditch 33,150 feet long. The fall in the upper 2 miles of the 
branch is slight, but below Augusta Road it is 44 feet in 3.6 miles. 
The lower mile of Manigault Branch is subject to overflow from the 
Savannah River, and while it is not absolutely necessary that the 
improvements extend down to Boggy Swamp, it is recommended that 
they be carried to that point, as this will provide a better outlet 
for the lands above. One 30-foot highway bridge will be needed. 
Mill Branch Swamp, between the flat bay in which tbe branch rises 
and Haskell Baroney Swamp, averages hardly more than 100 feet wide. 
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