12 BULLETIN 10&8, U. S. DEPARTMENT OF AGRICULTURE. 



growth was removed first, piled along the banks, and burned when 

 sufficiently dry. The trees, logs, and stumps were then removed and 

 placed upon the banks in suitable lengths for hauling away for use 

 as firewood. In many instances the roots of the larger trees and old 

 snags could not be removed without an amount of effort which would 

 have added greatly to the cost of the work. These were sawed off 

 even with the bed of the bayou and allowed to remain. They might 

 have been removed rather cheaply by the use of dynamite, had the 

 facilities for that work been available. The photographs repre- 

 sented by Plate III, Figure 3 ; Plate IV; and Plate V, Figure 1, give 

 a very good idea of the extent and nature of the work that was done. 

 The appearance of the stream during the operation of clearing is 

 shown in Plate V, Figures 2 and 3. 



CONSTRUCTION OF THE DAM. 



In njaking the fill, or cross levee, for the dam, advantage was 

 taken of a shallow point in the bed of the bayou used as a low- 

 water crossing by the tenants. The banks at this point were favor- 

 able — that is, high enough on either side to allow the water to 

 be' raised to the required level. The required height of water was 

 gained by running levels along the banks above the site of the dam. 

 The dam was constructed to give a depth of 4 feet 10 inches at the 

 floor of the spillway. When one recalls that the fall in the bed of 

 the bayou in this section averages only 0.6 foot to the mile, it is 

 seen that the level at the dam was carried back over the course of 

 the stream for a considerable distance with only a slight variation 

 in depth. The impounding was effective for depth about I mile 

 above the zone included in the survey, with the exception of a ridge 

 which crosses the bed of the bayou just above the last station. 



The details of the fill and spillway for the dam are shown in 

 Figure 2 and in Plate VI, Figures 1 and 2. The completed dam, 

 with bridge oyer the spillway, providing a roadway to the section 

 of the plantation lying on the opposite side of the bayou, is shown 

 in Plate VI, Figure 3. The labor and material involved in clearing 

 the bayou and in the construction of the fill and spillway for the 

 dam, are shown in Table 6. The bill of lumber for the spillway is 

 shown in Figure 2. 



Table 6. — Cost of clearing a section of Bayou Walnut and impounding water 



in same, 1915. 



Preliminary survey, running levels, plan and specifications of spillway $45. 00 



Clearing undergrowth and grass from bed and edges of bayou, includ- 

 ing piling and burning: 



15 men, 6 days, at $1.25__J $112. 50 



3 men, 5 days, at $1 1.5.00 



127.50 



