To His Excellency, William D. Jelks, Governor of Alabama: 



Dear Sir: I have the honor to transmit herewith a pre- 

 liminary report on the Water Powers of Alabama, by B. M<. 

 Hall, of the United States Geological Survey, Consulting 

 Engineer, Hydrographic Division, for Alabama, Florida, 

 Georgia, Tennessee, and Mississippi. 



Our Alabama Geological Survey, in cooperation with the 

 United States Geological Survey, has for a number of years 

 been engaged in a systematic investigation of the Water Re- 

 sources of the State. In this investigation we have naturally 

 been less interested in that portion of the rainfall which passes 

 back into the atmosphere by evaporation, than in those por- 

 tions which, temporarily at least, become more or less incor- 

 porated with the materials forming our land surface, and 

 which on that account may be considered as forming a part of 

 our territory. And our investigation of this earth water, (to 

 use a term to distinguish it from the atmospheric water), may 

 appropriately be followed along two lines : It may be con- 

 cerned, i, with that part of the wiater which, collecting in rivu- 

 lets, creeks and rivers, flows on towards the sea by open chan- 

 neds, i. e., the "run-off" ; or 2, it may take intto account that 

 part which soaks into the ground, and reaches^he water 

 courses or the sea only after an underground passage of 

 greater or less duration, i. e., the ground water or the "in- 

 soak," if we may be allowed the use oif such a word. 



While the proportion of the rainfall which appears in the 

 run-off of the streams varies between very wide limits, depend- 

 ing oni the geological formations, the locality, etc., in Alabama 

 on an average, about fifty per cent, of the rainfall is lost by 

 evaporation and the (remainder forms the run-off of the 

 streams, and, curiously enough, only a small percentage of this 

 run-off is supplied by the surface water alone, for most of it 

 reaches the water courses by underground seepage. 



In the course of this underground circulation the water may 

 reach the surface from springs, from ordinary shallow and deep 

 wells, and from artesian wells, and may be utilized for domestic 

 and municipal water supply, and rarely, in Alabama at least, for 

 irrigation and for power. 



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