LAND DRAINAGE BY MEANS OF PUMPS. 57 
head, and at the same time must be as efficient as practicable for 
more moderate heads. 
Since it has been shown that the average depth of water to be 
pumped from such districts per year will be about 15 inches, with 
well-designed and carefully operated plants the total cost per acre 
of drainage area per year should not exceed 80 cents for a mean lift 
of 5 feet and $1.20 for a mean lift of 10 feet. 
The administration of the business of the district should be placed 
in the hands of a competent engineer who is familiar with drainage 
work. He should be held entirely responsible for the proper admin- 
istration of the district business and especially for the operation and 
maintenance of the. pumping plant. Reliable, skilled attendants 
should operate the pumping plant under expert supervision and saould 
maintain it in first-class condition the entire year. Full records of 
the operation of the pumping plant should be kept, as well as detailed 
classification of expenditures, so that those in charge can determine 
at all times whether the operation of the plant is as economical as 
may be possible while securing the results desired from the plant. 
Where practicable, gravity outlet sluiceways should be installed in 
connection with a pumping plant for use during times of low water 
outside of the drainage district. 
The reclamation for agricultural purposes of river bottom lands 
lying so low that they are subject to serious injury by overflows has 
been proved by experience in this country and in Europe to be feasi- 
ble and profitable where the land is of sufficient fertility and where 
the improvements consist of a system of protective levees supple- 
mented by interior drainage ditches and a suitable pumping plant to 
remove excessive precipitation which may fall within the district. 
Such results, however, can come only when the entire plant is prop- 
erly designed and efficiently maintained and operated. 
