Long Island is underlain by a large ground-water reservoir of 



generally good quality it meets almost all the Island's fresh water needs 



the fresh and salty water systems are hydraul ical ly connected on the surface 



and below it the yield of the fresh ground-water reservoir is not a single 



fixed quantity; it will vary depending on hydrogeologic conditions, the 

 management scheme, and the extent to which undesirable effects of development 



will be tolerated the mainland on the north shore of the Sound is underlain 



by deposits of sand, gravel, silt and clay (stratified drift and till) and 

 bedrock the area contains many hydrological ly separate ground-water reser- 

 voirs of generally good quality large quantities of ground water may be 



pumped from wells tapping stratif ied-drift deposits whereas most individual 

 domestic wells obtain adequate water from bedrock. 



HOVI DOES SALT WATER CIRCULATE WITHIN LONG ISLAND SOUND? 



Long Island Sound is a 1,300 square mile water body with estuarine 

 characteristics in its western and central parts and embayment characteristics 



in its eastern third the minimum tidal range and maximum tidal currents 



occur at the eastern end and the maximum tidal range and minimum tidal cur- 

 rents at the western end circulation is controlled principally by tidal 



currents modified by fresh-water inflow, weather conditions and topography 



the circulation pattern of surface and near surface waters is fairly well 



defined, but relatively little is known about deep current circulation 



surface tidal current patterns in the central and eastern Sound are ellipti- 

 cal and counter-clockwise in direction at the eastern end, surface water 



flows into Block Island Sound, while more dense and saline bottom waters 



flow into Long Island Sound at the western end, surface water from the East 



River flows into the Sound and bottom waters move into the East River 



movement of water within major estuaries is complex because of the effects 



of tides and fresh-water inflow conditions understanding this movement is 



important for water management. 



WHAT WILL THE STUDY DO NEXT? 



It will work on solutions in all management areas information 



from this report and its supporting studies should be reflected in the 

 solutions, especially for water quality, water supply and flooding pro- 

 posals will be made to resolve major knowledge gaps such as the quantifica- 

 tion of the dynamic circulation system within the Sound and its major 

 estuaries. 



IV 



