2 BULLETIN 181. U. S. DEPARTMENT OF AGEICULTURE. 



the work. Field work was begun April 20 and finished August 15, 

 1913. 



The following report describes briefly the conditions found, dis- 

 cusses the drainage problems encountered, and presents the plan of 

 drainage considered most practicable. It is believed that this in- 

 formation will be decidedly helpful to engineers, drainage district 

 oflacials, residents, and owners of property in many locahties where 

 overflowed lands are to be reclaimed. 



GENERAL DESCRIPTION OF THE DISTRICT. 



LOCATION AND AREA. 



The lands examined comprise that section of the valley of the Big 

 Black River beginning near its source in Webster County, in the 

 central part of the State of Mississippi, and extending in a south- 

 westerly direction to the Alabama & Vicksburg Railway bridge, 14 

 miles east of Vicksburg, a total distance in a direct line of about 

 150 miles (see fig. 1). The bridge referred to is about 30 miles above 

 the junction of the Big Black River with the Mississippi, and marks 

 the head of navigation on the former stream. The total area of the 

 flooded land above Cox Ferry, the lower end of the proposed im- 

 provements, is 133,460 acres. 



TOPOGRAPHY. 



THE "WATERSHED. 



The watershed of the Big Black River consists of bottom land 

 from one-half mile to 2^ miles wide, bordered by rough, rolling land 

 and steep hills which extend back a few miles from the bottoms. 

 The surface of the rest of the watershed is rolling and in places quite 

 rough. In general the topography of the land is such that the run-off 

 is large and reaches the main streams in a short time. It is esti- 

 mated that 75 per cent of the upland has been cleared and was at 

 one time in cultivation, but a large part of it is now eroded and has 

 been allowed to grow up to pine and brush thickets. The areas 

 draining into the river at various points are shown in figure 2. 



The bottom lands are comparatively level, being broken only by 

 sloughs, old "ox bows," and bayous, formerly portions of the river 

 chaimel. In general the banks of the river are from 1 to 3 feet 

 higher than the land at the foot of the hills. From Mathiston to 

 Goodman the bottoms average from 1 to 1^ miles wide, and from 

 Goodman to Cox Ferry, near the Yazoo County line, the average 

 width is from 2 to 2J miles. At Cox Ferry the bottoms begin to 

 narrow rapidly, and from a point 2 miles below the Ferry to the 

 Alabama & Vicksburg Railway bridge average but from one-fourth 

 to one-half mile m width. The valley has a fall of 3 feet per mile at 



