236 American Fisheries Society. 



tion and substitution, have, therefore, been a means of more sav- 

 ing to the department than the entire cost of the surveys. 



LAKE SURVEYS. 



Investigations for the improvement of lakes have not merely 

 required biological investigations, but have presented civil en- 

 gineering problems as well, and have required a more extensive 

 survey than observations for streams. The most extensive work 

 of this character has been done in the southern part of the State, 

 where the results show most clearly the subsidence of the water- 

 table. Lake Shetek in Murray County is one of the largest lakes 

 so surveyed, having a shore-line of over 15^ miles. For many 

 years the level of this lake was controlled by a dam across the 

 stream below its outlet, the dam having been rebuilt several 

 times, each time a little higher, so that when it was finally 

 abandoned for water power with the disappearance of the dam 

 a few years ago, the abnormal water level so long sustained had 

 entirely destroyed the original contour of the lake and made 

 its restoration to its original meander level a problem of no mean 

 importance. Flood waters at its maximum artificial level had 

 inundated the high banks and washed them into the lake back a 

 distance of a hundred feet in some instances, the dirt so Avashed 

 in aiding enormously in filling up the natural shallow bed of the 

 lake until it is now found not to exceed 8 feet in depth anywhere 

 at extreme low water such as prevailed during the past summer 

 (1921). The destruction of so great an area of original shore- 

 line, and all landmarks along with it, rendered a determination 

 of its original level, fixed in 1861 by Government survey, difficult 

 in the extreme, and the position of original meander corners 

 could only be definitely determined by a resurvey of lines from 

 section corners beginning at considerable distances from the 

 lake shore. 



The accurate determination of the original meander is vital, 

 as we can not exceed its level without considerable damage to 

 surrounding lands, thereby laying the foundation for numerous 

 suits for damages from the owners. The actual filling up of this 

 lake bed, however, has not so seriously affected it as the de- 

 struction of its aquatic plant life which has been almost absolute ; 

 it has been claimed that the disappearance of this plant life is 

 due to the carp, and probably some of it has been destroyed by 



