76 
FLORIDA GEOLOGICAL SURVEY—THIRD ANNUAL REPORT. 
It is doubtless true that some of the lakes, especially the 
smaller ones, could be drained by surface ditching. Any attempt 
at drainage should be preceded, however, by the preparation of a 
carefully made topographic map of the region, or at least suffi¬ 
cient exact leveling should be made to determine definitely the rela¬ 
tion of the lake basin to the proposed outlet, and to the intervening 
country. 
While some of these lakes can be drained by bored wells it is 
not to be assumed that all can be so drained. As has been shown 
some of these lake basins, especially the larger ones, have been low¬ 
ered by solution practically to the permanent underground water 
level. Before attempting drainage by wells definite data should 
be obtained as to the relation between the level of the lake basin and 
the underground water level of that locality. This information 
can often be obtained by running a line of levels from the lake to a 
near by deep well and comparing the level of water in the lake with 
the level at which the water stands in the well. If necessary, test 
wells may be drilled before undertaking large wells. Such lakes 
as have been lowered by natural drainage actually to the under¬ 
ground water level can of course be lowered no further by wells 
