

(sections H--H' and I-I<)« 



In draidiig contours along tb© soath shore of Suffolk Coiinby the 1908 map by 

 tlie Board of Water Supply ims used as a gtdde^ allowance being made for the 

 general decline of water levels that is kaami to hare occtirred since that tiiae 

 (16) # Also allowance was made for the difference in datum planes « 



No contours are shown for tiiat area in Qijeens County lying north of the teav 

 idnal moraine^ except for the zero co3ntour« This contour encircles the center of 

 heavy pumpage in the Woodhaven area and separates tbe high area of north Queens 

 from the low area in Brooklyn* At two "stagnation points*^ it intersects the 

 closed 2Jero contour that coH?)letely encircles the island along its shoa?e# One 

 of these points is on Jamaica Bay and tJie other assoMedLy on Newtown Creeks A 

 simlar aero contotar separates the high area of Gravesend from the rest of 

 Brooklyn# 



Perhaps the most striking difference between the map on plate 1 and earlier 

 water-table contour inaps of Long ^sland is the configuration of the high in 

 Nassau County. The maximum elevation of the main ground-water table in Nassau 

 County in May 1945 was about 85 feet;^ or approximately 15 feet lower than shown 

 on the 1905 contour map* Ftnrthermore, the high point in 1945 was about 5 miles 

 west of its position according to the 1905 map# However^ it must be kept in 

 Brind tliat on the 1903 map the contours in that area were drawn as dotted lines^ 

 indicati33g that the position of the true -water table was conjectural, as pointed 

 out above (p« 10) • Coiaparison of the two water tables is best seen on section 

 G-G% plate 2« Section F-F' shows the same divergence of levels^ though to a 

 lesser degree* 



Differences in average elevation cf the water table in 1903 and 1943 as 

 shown on the other sections of plate 2 is attributable partly to differences in 

 precipitation* A recent study QS) of early water levels ai^ precipitation and 



