k.5 Lakes and ponds 



There are hundreds of lakes and ponds of various size mostly 

 located in the Connecticut part of the Long Island Sound Region. The larger 

 lakes are generally man made and are used for water supply, flood control 

 and recreation. Table 1 lists pertinent data on the major lakes and ponds 

 in Connecticut. 



5.0 GROUND WATER 



5. 1 Availability of hydrogeologic data 



Hydrogeologic information for the Long Island Sound Region is 

 contained in numerous basic data and interpretive reports. Most interpretive 

 studies published prior to I960 are qualitative and cover relatively small 

 parts of the region. Recent comprehensive reports include the series of 

 Water Resources Bulletins prepared by the U.S. Geological Survey in coopera- 

 tion with the State of Connecticut {ZJj 36, JTj 3_L) ; New York Water Resources 

 Commission Bulletins {5j 8) and several U.S. Geological Survey Water-Supply 

 and Professional Papers prepared in cooperation with New York State and 

 county agencies (6^ 10, 25, 26, 3^ ) . 



Water-level and ground-water quality data from wells within the 

 study region are published each year in Water Resources Data for Connecticut, 

 Parts 2 and 3 (^ ; and Water Resources Data for New York, Part 2 {kT) . 

 Water levels are also published on a monthly basis in Water Resources Condi- 

 tions in Connecticut (43) and Water Resources Summary, Long Island ( kk) . 



The existing information on ground-water availability and quality 

 necessary for planning has been updated and presented in map format for this 

 study (see Appendix C) . In some aspects of plan formulation it may be nec- 

 essary to refer to information contained in the selected references listed in 

 Appendix A. 



5.2 The hydrogeologic system of Long Island 



Two recent reports (5^ 1 0) have summarized the pertinent existing 

 information on Long Island's hydrologic system and are the basis of this 

 section. Although Long Island is generally considered as a single hydrologic 

 unit it can be divided into subareas for purposes of analysis. Subareas 

 referred to in the text and on tables are shown on Figure 11. 



The most important hydrologic feature of Long Island is the fresh 

 ground-water reservoir beneath its surface. The boundaries of this reservoir 

 are (1) the water table (2) the fresh-salt water interfaces (3) the bedrock 

 surface and (4) the streams. The geologic framework of the ground-water 

 reservoir consists of a thick wedge-shaped mass of saturated sand, gravel, 

 silt and clay as shown on Figure 12. 



2k 



