WATER SUPPRY OP EASTERN AND SOUTHERN ERORIDA. 157 
THE AREAS OF ARTESIAN FLOW IN FLORIDA. 
The accompanying map indicates, in a general way, the flow¬ 
ing and non-flowing areas of the State. In using such general 
maps it should be borne in mind that artesian water depends 
primarily upon the structure of the underlying formations, and 
these are subject to variations of which there may be no surface 
indications. Moreover, local elevations which affect flow can not 
be indicated on a small scale map. Thus while the map indicates 
approximately the limits of flow, the exact limits can be deter¬ 
mined in most cases only by drilling. 
The shading on the map indicates those parts of the State in 
which flowing wells have been obtained, or may be expected. 
There are, as will be seen, three principal areas of flow as follows: 
the Atlantic Coast area, the Southern Gulf Coast area and the 
Western Gulf Coast area. 
THE ATLANTIC COAST AREA. 
The Atlantic Coast area includes much of Nassau and Duval 
Counties, and, with the exception of local elevated areas, all of 
St. Johns County; it follows the valley of the St. Johns River 
almost if not quite to the head waters, while a narrow strip reaches 
south along the Atlantic Coast for 250 to 300 miles. The artesian 
water-bearing formation dips in passing to the south, being- 
reached at Palm Beach at the depth of about 1,000 feet. In addi¬ 
tion to its increased depth the water at Palm Beach was jfound to 
be too salty to be used for household purposes. Between Palm 
Beach and Key West no wells have been drilled deep enough to 
reach this formation. The deep well drilled on Key Vaca by the 
Florida East Coast Railway terminated at 700 feet in quartz sands, 
with sandstones and clay in streaks, not having reached the Vicks¬ 
burg Limestone.* 
At Key West two wells have* been drilled to the Vicksburg, 
which is reached at that locality at a depth of about 700 feet. 
The first of these wells, drilled in 1895, is reported to have 
^Florida Geol. Survey, Second Annual Report, p. 205, 1909. 
