WATER-POWERS OF ALABAMA. 



163 



Sec.-ft. 



From 1890 to 1895, inclusive '. IH. 



From 1896 to 1900, inclusive 6, GOO 



From January 1 to November 16, 1901, inclusive 12,930 



From this it is estimated that 6,600 second-feet is the mini- 

 mum discharge for driest years, and that 12,930 second-feet is 

 the minimum for average years. Assuming that tributaries en- 

 tering the river below Chattanooga will safely supply all of the 

 water needed for lockage, we can use these discharges in esti- 

 mating the water power of these shoals, which are about 200 

 miles below Chattanooga, by river, and drain an area more than 

 7,000 square miles greater than the watershed above Chatta- 

 nooga. 



Estimated minimum net horsepower of Tennessee River in Alabama 

 on turbines realizing 80 per cent, of the theoretical power. 



Total j 155 | 93,000 | 182,125 



The foregoing table assumes that the total fall can in each 

 case be utilized. While this assumption is not correct, it stands 

 as an offset to the assumption that the water supply available 

 will be as low as the minimum discharge at Chattanooga, 200 

 miles above. The drainage area above Chattanooga is 21,418 

 square miles, while the drainage area above the shoals under 

 consideration is about 29,000 square miles. It may therefore 

 safely be assumed that the actual power available for develop- 

 ment at the shoals is greater than that shown by the table. 



The foregoing statements of fall and distance are from a re- 

 port by Mr. William B. Gaw, chief assistant engineer, United 

 States Army, 1868, and the map and profile are from draw- 

 ings prepared under the direction of Lieut. Col. J. W. Barlow, 

 United States Engineers, 1890. 



