WET LANDS OF SOUTHEKN"' LOUISIANA. 63 



Cost of Operation. 



Records of operation have been kept for a number of pumping plants In 

 drainage service in southern Louisiana. Not all of the plants included in these 

 records are typical, neither have conditions been typical, but it is believed that 

 it will be of service to include all the plants so that a comparison may be made 

 of the saving in cost of operation that may be effected, first, by having good 

 levees around the district; second, by properly installing efficient and suitable 

 machinery ; third, by operating the plant carefully. 



The equipment of each pumping plant, as well as the kinds and costs of fuel 

 and labor, are shown in Table II. Table III shows the costs of operation, 

 including fuel, labor, and repairs ; it also shows the conditions under which 

 the plants were operated. For the purpose of comparing the costs for the 

 various plants a unit has been chosen which eliminates any effect of differences 

 in the amounts of water pumped and lifts of the pumps-; this unit is the cost 

 of lifting 1 acre-foot of water 1 foot. Of course the pumps with the higher 

 average lifts worked at a relatively greater efficiency. It should be noted that 

 Table III shows average effective lift rather than the actual lift, the former 

 being the difference between the elevation of the water surface from which 

 water is being pumped and that of the water surface where the pumps 

 discharge. The cost of pumping likewise is expressed in the cost of lifting 

 1 acre-foot of water 1 effective foot. 



As an example of the large amount of pumping that may be caused by seepage 

 through poorly designed or built levees, the results for 1912 and 1913 on the 

 Smithport tract and those for 1913 for the Gueydan district should be compared 

 with the results for 1913 and 1914 from subdistrict No. 3 at Raceland. The 

 amount of water pumped on the latter district was scarcely half that pumped 

 on the other two districts, although the amount of rainfall was not far different. 



The cost figures given in the table must be compared with due regard to 

 conditions of operation and to the average lift of the pumps. The effect of a 

 change of lift of a pump is shown in the figures for nearly all the plants, but 

 especially in those for reclamation district No. 1 at Poydras, subdistrict No. 1 

 at Des Allemands, and subdistrict No. 3 at Raceland. On certain other of the 

 plants the fact that an increase in lift has not caused a decrease in unit cost 

 is due to the increase in fuel cost. 



As all of the Corliss engine plants are on large districts, a condition that tends 

 to a relatively large reduction in the labor charge per unit of water lifted out 

 of the district, it will be advisable to disregard the item of labor and make the 

 comparison on cost of fuel alone ; this will largely eliminate the effect of the 

 size of the district. With the exception of the year 1914, the cost in fuel of 

 lifting an acre-foot of water 1 foot was much less for the Corliss engine plants 

 than for those using slide-valve engines. The plants in subdistrict No. 1 at 

 Gueydan and Jefferson drainage district No. 3 are similar in equipment, except 

 that the pumps in the Gueydan district are larger. It will be noted that the 

 cost of fuel used per unit of water lifted (Table III) is less for the Gueydan 

 district than for the other. The lifts and the lengths of run per fire up are 

 about the same, while the unit cost of fuel (Table II) is lower for the Jefferson 

 plant. This difference in cost of operation might be due partly to the fact that 

 these two plants have the same sized engines, which results in the engines in 

 the Gueydan plant working at about their proper capacity, while those in the 

 Jefferson plant are working at a considerable underload. No doubt, however, 

 the greater part of the difference is in the care with which the oil has been 

 fired under the boilers. 



