________________________________________________________________________ 

U.S. Department of the Interior 

U.S. Geological Survey 

DOCUMENTATION OF REVISIONS TO THE 

REGIONAL AQUIFER SYSTEM ANALYSIS MODEL OF 

THE NEW JERSEY COASTAL PLAIN 

Water-Resources Investigations Report 03-4268 

In cooperation with the 

NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION 
________________________________________________________________________ 

DOCUMENTATION OF REVISIONS TO THE 

REGIONAL AQUIFER SYSTEM ANALYSIS MODEL OF 

THE NEW JERSEY COASTAL PLAIN 

By Lois M. Voronin 

U.S. Geological Survey 

Water-Resources Investigations Report 03-4268 

In cooperation with the 

NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION 
U.S. DEPARTMENT OF THE INTERIOR 

GALE A. NORTON, Secretary 

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director 

For additional information Copies of this report can be 

write to: purchased from: 

District Chief 

U.S. Geological Survey U.S. Geological Survey 

Mountain View Office Park Branch of Information Services 

810 Bear Tavern Road Box 25286 

West Trenton, NJ 08628 Denver, CO 80225-0286 
 iii 

Contents 

Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Location and extent of study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3


Previous investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Conceptual hydrogeologic model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3


Hydrogeologic framework. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Ground-water-flow system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Original and revised model designs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Model approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Grid design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4


Ground-water withdrawals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Lateral and lower boundary conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9


Upper boundary conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


Recharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Model calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Revisions to model input data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Recharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Vertical leakance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Storage coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


Boundary fluxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


Simulated potentiometric surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


1978 ground-water-flow conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


1998 ground-water-flow conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


Simulated and measured water-level hydrographs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31


Base flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31


Model limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31


Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48


References cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48


Plate 

[In pocket] 

1.	 Map showing finite-difference grid and generalized lateral boundaries of the original and revised Regional Aquifer System 

Analysis models 

CD-ROM 

[In pocket] 

1.	 Read me file and model files. 
iv 

Figures 

1.	 Map showing location of study area and Critical Water Supply areas 1 and 2 in New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . .2


2.	 Generalized hydrogeologic section of the New Jersey Coastal Plain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5


3.	 Schematic representation of aquifers, confining units, and boundary conditions used in the revised


New Jersey Coastal Plain ground-water-flow model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6


4.	 Graph showing average and total annual ground-water withdrawals for each stress period for the


New Jersey Coastal Plain, 1968-98 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8


5. Map showing model cells that represent stream reaches in the study area, New Jersey Coastal Plain. . . . . . . . . . . . . . . . . 12


6 - 8. Maps showing:


6.	 Recharge rates used in the model and the location of selected drainage basins and 


streamflow-gaging stations in the model area, New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14


7.	 Location of, and references for, studies that reported ground-water recharge rates 


in the New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


8.	 Vertical leakance used in the model for the Navesink-Hornerstown confining unit 


and location of selected wells in the study area, New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16


9.	 Hydrographs of measured and simulated water levels in well 25-486 screened in the Wenonah-Mount Laurel


aquifer that result from two model scenarios with storage coefficients of 0.001 and 0.0001, New Jersey


Coastal Plain, 1985-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


10 - 22. Maps showing: 

10.	 Location of ground-water withdrawal wells screened in the Lower Potomac-Raritan-Magothy aquifer


in Delaware, 1997. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19


11.	 Simulated and interpreted potentiometric surfaces of the (a) Wenonah-Mount Laurel


aquifer and (b) Englishtown aquifer system, New Jersey Coastal Plain, 1978 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20


12.	 Simulated water table of the Holly Beach water-bearing zone, New Jersey Coastal


Plain, 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21


13.	 Simulated water table and simulated potentiometric surfaces of the upper Kirkwood-


Cohansey aquifer, New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22


14.	 Simulated and interpreted potentiometric surfaces of the lower Kirkwood Cohansey


aquifer system and confined Kirkwood aquifer, New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23


15.	 Simulated and interpreted potentiometric surfaces of the Piney Point aquifer,


New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24


16.	 Simulated and interpreted potentiometric surfaces of the Vincentown aquifer, 


New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25


17.	 Simulated and interpreted potentiometric surfaces of the Wenonah-Mount Laurel


aquifer, New Jersey Coastal Plain, 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26


18.	 Simulated and interpreted potentiometric surfaces of the Englishtown aquifer system,


New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27


19.	 Simulated and interpreted potentiometric surfaces of the Upper Potomac-Raritan-


Magothy aquifer, New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28


20.	 Simulated and interpreted potentiometric surfaces of the Middle Potomac-Raritan-


Magothy aquifer, New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29


21.	 Simulated and interpreted potentiometric surfaces of the Lower Potomac-Raritan-


Magothy aquifer, New Jersey Coastal Plain, 1998. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30


22.	 Location of selected observation wells for which hydrographs of simulated and 


measured water levels have been plotted, New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

 v 

Figures—Continued 

23 – 49. Hydrographs of simulated and measured water levels in observation well: 

23.	 Well 29-141 screened in the Kirkwood-Cohansey aquifer system, New Jersey 


Coastal Plain, 1978-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33


24.	 Well 1-578 screened in the confined Kirkwood aquifer, New Jersey Coastal Plain, 1978-98. . . . . . . . . . . . . . . . . . . . . . . 33


25.	 Well 1-37 screened in the confined Kirkwood aquifer, New Jersey Coastal Plain, 1973-98 . . . . . . . . . . . . . . . . . . . . . . . . 34


26.	 Well 1-834 screened in the Piney Point aquifer, New Jersey Coastal Plain, 1988-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34


27.	 Well 5-676 screened in the Piney Point aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35


28.	 Well 11-96 screened in the Piney Point aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35


29.	 Well 29-139 screened in the Vincentown aquifer, New Jersey Coastal Plain, 1978-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36


30.	 Well 25-636 screened in the Vincentown aquifer, New Jersey Coastal Plain, 1987-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36


31.	 Well 25-353 screened in the Wenonah-Mount Laurel aquifer, New Jersey Coastal Plain, 1984-97 . . . . . . . . . . . . . . . . 37


32.	 Well 7-478 screened in the Wenonah-Mount Laurel aquifer, New Jersey Coastal Plain, 1973-98.. . . . . . . . . . . . . . . . . 38

33.	 Well 25-637 screened in the Wenonah-Mount Laurel aquifer, New Jersey Coastal Plain, 1987-98.. . . . . . . . . . . . . . . . 38


34.	 Well 29-140 screened in the Wenonah-Mount Laurel aquifer system, New Jersey Coastal Plain, 1978-98.. . . . . . . . 39


35.	 Well 29-138 screened in the Englishtown aquifer system, New Jersey Coastal Plain, 1973-98.. . . . . . . . . . . . . . . . . . . . 39


36.	 Well 25-429 screened in the Englishtown aquifer system, New Jersey Coastal Plain, 1978-98. . . . . . . . . . . . . . . . . . . . . 40


37.	 Well 25-638 screened in the Englishtown aquifer system, New Jersey Coastal Plain, 1987-98. . . . . . . . . . . . . . . . . . . . . 40


38.	 Well 5-259 screened in the Englishtown aquifer system, New Jersey Coastal Plain, 1973-98. . . . . . . . . . . . . . . . . . . . . . 41


39.	 Well 5-258 screened in the Upper Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . 41


40.	 Well 7-477 screened in the Upper Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . 42


41.	 Well 15-728 screened in the Upper Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1987-98. . . . . . . 42


42.	 Well 25-639 screened in the Upper Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1987-98. . . . . . . 43


43.	 Well 5-261 screened in the Middle Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . 43


44.	 Well 15-713 screened in the Middle Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1987-1998 . . . 44


45.	 Well 33-251 screened in the Middle Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1978-98. . . . . . 44


46.	 Well 7-283 screened in the Lower Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . 45


47.	 Well 33-187 screened in the Lower Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98.. . . . . . 45


48.	 Well 15-712 screened in the Lower Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1987-98.. . . . . . 46


49.	 Well 5-262 screened in the Lower Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. . . . . . . . 46


Tables 

1.	 Previous simulation studies conducted for the New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


2.	 Geologic and hydrologic units of the New Jersey Coastal Plain and model units used in the


revised Regional Aquifer System Analysis model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


3.	 Average daily ground-water withdrawals from each aquifer and lateral boundary flows by 


stress period, New Jersey Coastal Plain, 1968-98 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


4.	 Simulated and estimated base flows at five continuous-record streamflow-gaging stations in 


the New Jersey Coastal Plain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

vi 

 vii 

Conversion Factors and Datum


Multiply By To obtain 

Length 

inch (in.) 2.54 centimeter (cm) 

inch (in.) 25.4 millimeter (mm) 

foot (ft) 0.3048 meter (m) 

mile (mi) 1.609 kilometer (km) 

Area 

square mile (mi2) 2.590 square kilometer (km2) 

Volume 

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

million gallons (Mgal) 3,785 cubic meter (m3) 

Flow rate 

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) 

gallon per minute (gal/min) 0.06309 liter per second (L/s) 

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d) 

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s) 

Hydraulic conductivity 

1foot per day (ft/d) 0.3048 meter per day (m/d) 

Transmissivity 

2foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d) 

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD of 29). 

1

The standard unit for hydraulic conductivity is cubic foot per day per square foot of aquifer cross-sectional area, or 

(ft3

/d)/ft2. In this report, this expression is reduced to its simplest form, foot per day (ft/d). 2The standard unit for transmissivity is cubic foot per day per square foot times feet of aquifer thickness, or 

[ft3

/d)/ft2]ft. In this report, this expression is reduced to its simplest form, square foot per day (ft2/d). 
Documentation of Revisions to the Regional Aquifer 

System Analysis Model of the New Jersey Coastal Plain 

By Lois M. Voronin 

Abstract 

The model, which simulates flow in the New Jersey 

Coastal Plain sediments, developed for the U. S. Geological 

Survey Regional Aquifer System Analysis (RASA) program 

was revised. The RASA model was revised with (1) a rediscretization of the model parameters with a finer cell size, (2) a spatially variable recharge rate that is based on rates determined by 

recent studies and, (3) ground-water withdrawal data from 1981 

to 1998. 

The RASA model framework, which subdivided the 

Coastal Plain sediments into 10 aquifers and 9 confining units, 

was preserved in the revised model. A transient model that simulates flow conditions from January 1, 1968, to December 31, 

1998, was constructed using 21 stress periods. 

 The model was calibrated by attempting to match the simulated results with (1) estimated base flow for five river basins, 

(2) measured water levels in long-term hydrographs for 28 

selected observation wells, and (3) potentiometric surfaces in 

the model area for 1978, 1983, 1988, 1993, and 1998 conditions. The estimated and simulated base flow in the five river 

basins compare well. In general, the simulated water levels 

matched the interpreted potentiometric surfaces and the measured water levels of the hydrographs within 25 feet. 

Introduction 

As part of an ongoing program to maintain ground-waterflow models constructed in New Jersey, the U.S. Geological 

Survey (USGS), in cooperation with New Jersey Department of 

Environmental Protection (NJDEP), developed a standardized 

procedure to archive the models and revise selected models by 

incorporating recent data, such as withdrawal data and simulation techniques. The Regional Aquifer System Analysis finitedifference numerical model of flow in the New Jersey Coastal 

Plain sediments (Martin, 1998) was revised by (1) rediscretizing the model parameters with a finer cell size, (2) using a spatially variable recharge rate that is based on rates determined in 

studies conducted since the model was initially developed in 

1981 and, (3) using recent ground-water withdrawal data for 

1981-98. 

The New Jersey Coastal Plain flow model was constructed 

in 1978 for the U.S Geological Survey Regional Aquifer System Analysis (RASA) program (Martin, 1998). The objective of 

the RASA program was to appraise the major ground-water systems in the United States. For the RASA program in New Jersey, a regional model of flow in 10 aquifers and through 9 intervening confining units that compose the New Jersey Coastal 

Plain sediments was developed. Because of the large model 

area, 9,000 mi2, and the limited computer capabilities, the 

model was designed with a coarse grid. Cell size ranged from 

6.25 mi2 in the southeastern Coastal Plain to 47.5 mi2

 in offshore areas. 

The goals of the RASA program were met with the original 

model design; however, the current water-management needs in 

New Jersey require a more detailed model that incorporates 

recent simulation techniques and the most recent (1998) 

ground-water withdrawal data. Instead of constructing a new 

model of the New Jersey Coastal Plain sediments, the RASA 

model was updated. 

In 1986 in response to rapidly declining water levels in the 

New Jersey Coastal Plain, the NJDEP designated Critical 

Water-Supply Areas 1 and 2 (fig. 1). Critical Area 1 is located 

in parts of Middlesex, Monmouth, and Ocean Counties. Withdrawals from the Wenonah-Mount Laurel aquifer, Englishtown 

aquifer system, and the Upper and Middle Potomac-RaritanMagothy aquifers within Critical Area 1 were restricted beginning in 1989. Critical Area 2 is located in Camden and parts of 

Atlantic, Burlington, Cumberland, Gloucester, Monmouth, 

Ocean, and Salem Counties. Ground-water withdrawals from 

the Upper, Middle, and Lower Potomac-Raritan-Magothy aquifers in Critical Area 2 were restricted beginning in 1996. As a 

result of the reduced ground-water withdrawals in these areas, 

water levels have risen as much as 110 ft from 1988 to 

1998(Lacombe and Rosman, 2001). The updated RASA model 

can be used to evaluate the regional effect of reduced groundwater withdrawals on water levels and as a tool to re-evaluate 

water-management strategies in these areas. 
2 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

77
 76
 75
 74
 73
 72


41


40


39


38


37


NEW YORK CONNECTICUT 

LONG ISLAND 

DELAWARE 

VIRGINIA 

OCEAN MODEL BOUNDARY

FALL LINE 

Coastal Plain 

NEW 

JERSEY 

STUDY AREA BOUNDARY 

0 25 50 MILES 

0 25 50 KILOMETERS 

75 74 

41 

40 

39 

0 20 KILOMETERS 

0 10 20 MILES

CONNECTICUT

NEW YORK 

ATLANTIC OCEAN 

NEW YORK 

SUSSEX 

MORRIS 

BERGEN 

ESSEX 

UNION HUDSON

MIDDLESEX 

MERCER MONMOUTH

SOMERSET 

HUNTERDON 

OCEAN 

GLOUCESTER CAMDEN

SALEM 

CUMBERLAND 

CAPE 

KENT 

NEW

CASTLE 

Modified from Martin, 1998 

From N.J. Department of 

Environmental Protection 

unpublished, 1:250,000. 

Boundaries are approximate 

and should not be used for 

regulatory compliance 

purposes. 

FALL 

LINE 

PENNSYLVANIA 

MARYLAND 

ATLANTIC 

10 

PENNSYLVANIA DELAWARE 

WARREN 

BURLINGTON 

ATLANTIC 

MAY 

PASSAIC 

Water-Supply Critical Area--

EXPLANATION 

Critical Area #1 

Critical Area #2 

Base from U.S. Geological Survey Modified from Watt, 2000


digital line graph files, 1:24,000


Figure 1. Location of study area and Critical Water Supply areas 1 and 2 in New Jersey. 
Introduction 3 

The revised RASA model also can be used to evaluate the 

regional effect on water levels of a proposed increase in groundwater withdrawals of 2,017 Mgal/d in Salem and Gloucester 

Counties. This area is adjacent to an area that has experienced 

water-level declines of more than 100 ft since pumping began 

in the early 1900’s. Results of the withdrawal scenarios can be 

used to evaluate alternative resource-management strategies in 

these areas. 

Purpose and Scope 

The purpose of this report is to document the revisions 

made to the RASA model (Martin, 1998). The report includes a 

detailed analysis of the calibration. Values for simulated and 

estimated base flow in five river basins in the New Jersey 

Coastal Plain are presented in tables and hydrographs of simulated and measured water levels in 28 observation wells, and 

simulated and interpreted potentiometric surfaces for 1998 conditions are shown in figures. The model simulates withdrawal 

conditions from 1968 to 1998. 

Location and Extent of Study Area 

The extent of the model area shown in figure 1 is the same 

as that of the RASA model. The RASA model includes all of the 

New Jersey Coastal Plain sediments and extends into New Castle County, Delaware and Philadelphia and Bucks Counties, 

Pennsylvania. For this study, revisions were made only to an 

area within the New Jersey Coastal Plain sediments, which is 

indicated by the shading on the inset map shown in figure 1. The 

study area is smaller than the model area, includes all of New 

Jersey, and extends offshore about 20 mi in the southeast. 

Previous Investigations 

The two previous studies where simulation techniques 

were used to investigate the regional ground-water flow system 

of the New Jersey Coastal Plain are listed in table 1 along with 

the year of the most recent water-level data and the minimum 

cell size. Studies conducted prior to 1980 were limited in extent 

and focused on ground-water flow in one aquifer; these studies 

are not cited in this report. Martin (1998) developed the first 

regional ground-water-flow model that included all the aquifers 

of the New Jersey Coastal Plain (RASA model). Pope and Gordon (1999) expanded on Martin’s work and simulated groundwater flow in the New Jersey Coastal Plain aquifers that extend 

to the Continental Shelf (CP model). 

Conceptual Hydrogeologic Model 

The hydrogeology of the New Jersey Coastal Plain is discussed briefly in this section. The New Jersey Coastal Plain sediments are described in detail by Zapecza (1989). 

Hydrogeologic Framework 

The New Jersey Coastal Plain sediments consist of alternating layers of gravel, sand, silt, and clay that gently dip and 

thicken to the southeast and overlie crystalline bedrock (fig. 2). 

Most aquifers and confining units in the New Jersey Coastal 

Plain were mapped by Zapecza (1989). Martin (1998) modified 

the hydrogeologic framework presented in the report by 

Zapecza for the RASA model and represented the Coastal Plain 

sediments as 10 major aquifers and 9 intervening confining 

units. 

Ground-Water-Flow System 

The Coastal Plain ground-water-flow system is dynamic 

(changes with time) and has changed greatly in response to 

ground-water withdrawals. A brief discussion of the current 

(1998) ground-water-flow system is given here. For a more 

detailed discussion of the ground-water-flow system see Martin 

(1998). Ground-water flow in the New Jersey Coastal Plain sediments under current conditions (1998) is affected by the 

hydraulic properties of the saturated sediments, topography, 

and ground-water withdrawals. In general, topographic highs 

are recharge areas and topographic lows are discharge areas. 

Ground-water withdrawals in topographic lows can reverse 

ground-water-flow directions in these areas, which then can 

become ground-water recharge areas. Discharge areas in the 

New Jersey Coastal Plain include the Atlantic Ocean, the Delaware River, the Delaware and Raritan Bays, and streams. Examples of recharge areas are the high-altitude areas (250 ft., 

NGVD of 1929) in northwestern Monmouth County. 

In general, aquifers transmit water easily compared to confining units, which transmit water only to a small extent. Flow 

within confining units is predominantly vertical as a result of 

large vertical gradients within confining units. Flow within 

aquifers is horizontal with a small vertical component. 

Table 1. Previous simulation studies conducted for the New Jersey Coastal Plain 

[RASA, Regional Aquifer System Analysis; CP, Coastal Plain] 

Model (acronym) Reference 

Most recent waterlevel data used in 

study 

Minimum cell size 

(square miles) 

RASA Martin (1998) 1978 6.25 

CPOP Pope and Gordon (1999) 1988 6.25 
4 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

Six steep regional cones of depression have developed in 

the New Jersey Coastal Plain. Two cones are centered in southern Monmouth and northwestern Ocean Counties, three in central Camden County, and one in southeastern Atlantic County 

(Lacombe and Rosman, 2001, sheets 3, 6, 7, 8, 9, 10). All of 

these regional cones of depression have developed in response 

to the decline in water levels that resulted from large groundwater withdrawals that began in the late 1800’s. 

Original and Revised Model Designs 

The RASA model was compiled on an early computer system for a multi-layer finite-difference ground-water-flow 

model. The model computer code used to simulate groundwater flow was a modified version (Leahy, 1982) of the computer program developed by Trescott (1975). For this study, the 

input data were formatted for use with MODFLOW-96, a version of the modular finite-difference ground-water-flow model 

by Harbaugh and McDonald (1996). 

Model Approach 

For the quasi-three dimensional representation of the aquifers and confining units of the New Jersey Coastal Plain, flow 

is assumed to be entirely horizontal within the aquifers and vertical through the confining units. Water levels within the confining units were not simulated, but vertical flow through the 

confining units was calculated by using vertical leakance (vertical hydraulic conductivity divided by thickness). The RASA 

model assignment of the Coastal Plain sediments into aquifers 

and confining units was not changed in the revised model. The 

geologic and hydrogeologic units and the corresponding modellayer designations used in the model are listed in table 2. A generalized hydrogeologic section of the New Jersey Coastal Plain 

and the designated model layers are shown in figure 2. A schematic representation of the model units used to represent the 

hydrogeologic units (fig. 2) is shown in figure 3. Martin (1998) 

modeled the 10 major aquifers and the streams using an 11-

layer model. Martin modeled the streams as a layer. In the 

revised model, the streams were modeled using the river and 

drain package of MODFLOW-96. Hence, an 11th layer was not 

needed in the revised model. 

Grid Design 

The RASA grid cell size was 6.25 mi2 in the northern and 

southwestern New Jersey Coastal Plain, 9.375 mi2

 in the southeastern Coastal Plain, and as much as 47.5 mi2

 in offshore areas 

(plate 1). The grid had 29 rows and 51 columns. In the new grid 

(plate 1) with 135 rows and 245 columns, the cell size is 0.25 

mi2 in the northern and southwestern New Jersey Coastal Plain, 

0.31 mi2

 in the southeastern Coastal Plain, and as much as 3.16 

mi2 in offshore areas. The ratio of the number of new cells to 

the original number of cells is 25 to 1 in onshore areas. 

Rows 1 and 29 and columns 1 and 51 were not active in the 

RASA model and are not included as part of the grid area of the 

revised model. The relation between the RASA and revised 

model grids is shown in plate 1. 

Ground-Water Withdrawals 

A transient ground-water-flow model that simulates conditions from January 2, 1968, to December 31, 1998, was constructed with 21 stress periods and 10 time steps within each 

stress period. Ground-water withdrawal data used in the revised 

model are those reported to the NJDEP by water purveyors. The 

withdrawal data also are maintained in a USGS computer database. Average annual withdrawals were used for all stress periods (fig. 4). Because stress periods 4 through 21 are 1 year in 

length, average annual withdrawals are equivalent to total 

annual withdrawals during these stress periods. Withdrawals 

for stress periods 1 to 3 are the same as withdrawals for stress 

periods 7, 8, and 9 of the RASA model. Stress period 1 extended 

from January 2, 1968, to January 1, 1973; period 2, January 2, 

1973, to January 1, 1978; and period 3, January 2, 1978, to January 1, 1981, in the RASA model. Annual ground-water withdrawals for these three stress periods were averaged for these 3- 

to 5-year time periods. In the revised model, stress periods 2 and 

3 have the same time periods as stress periods 8 and 9 in the 

RASA model; however, stress period 1 in the revised model 

represents an interval of 100 years. 

The use of a time interval of 100 years enabled the model 

to simulate steady-state flow conditions using average groundwater withdrawals from January 2, 1968, to January 1, 1973. 

Initial water levels for this period were the water levels calculated from the original model for average conditions during 

1968-73. During the sensitivity analysis of the effects of withdrawals on the ground-water-flow system, Martin (1998) found 

that after 10 years with a constant pumping rate the change in 

water levels would be less than 1 ft/yr anywhere in the aquifer 

system. A period of 100 years was more than enough time to 

simulate steady-state flow conditions with average from January 2, 1968, to January 1, 1973, ground-water withdrawals. In 

Martin (1998), water-level changes simulated after only 10 

years also were slight, such that the residual effect of changes in 

withdrawals rates prior to 1968 (if they were simulated) would 

have little effect on the simulated response during the period of 

interest, after 1978. 

Water levels simulated with the revised model at the end 

of stress periods 1, 2, and 3 are comparable to those at the end 

of stress period 7, 8, and 9 simulated with the RASA model. 

Water levels at the end of stress period 2 are comparable to the 

1978 water levels that Martin (1998) used for calibration. 
model units listed in table 2 

model units listed in table 2 

Not to scale 

LOWER POTOMAC-RARITAN-MAGOTHY AQUIFER (A10) 

MIDDLE POTOMAC-RARITAN-MAGOTHY AQUIFER (A9) 

UPPER POTOMAC-RARITAN-MAGOTHY AQUIFER (A8) 

CONFINING UNIT BETWEEN THE LOWER AND MIDDLE POTOMAC-RARITAN-MAGOTHY AQUIFERS (C9) 

CONFINING UNIT BETWEEN THE MIDDLE AND UPPER POTOMAC-RARITAN-MAGOTHY AQUIFERS (C8) 

MERCHANTVILLE-WOODBURY CONFINING UNIT (C7) 

BEARING ZONE (A1) 

BASAL KIRKWOOD CONFINING UNIT (C3) 

PINEY POINT AQUIFER (A4) 

VINCENTOWN-MANASQUAN CONFINING UNIT (C4) 

WENONAH-MOUNT LAUREL AQUIFER (A6) 

UPPER KIRKWOOD-COHANSEY AQUIFER (A2) 

N SOUTHEAS T

OCEAN 

BEDROCK 

MARSHALLTOWN WENONAH CONFINING UNIT (C6) 

5 

Figure 2. 

AQUIFER Numbers refer to 

CONFINING UNIT Numbers refer to 

EXPLANA TION 

ENGLISHT OWN AQUIFER (A7) 

F ALL LINE 

HOLL Y BEACH W A TERESTUARINE CLA Y 

CONFINING UNIT (C1) 

CONFINING UNIT OVERL YING THE 

RIO GRANDE W A TER-BEARING ZONE (C2) 

VINCENT OWN AQUIFER (A5) 

NA VESINK-HORNERST OWN CONFINING UNIT (C5) 

OR THWEST 

ATLANTIC 

LOWER KIRKWOOD-COHANSEY AND 

CONFINED KIRKWOOD AQUIFER (A3) 

Original and Revised Model Designs 

Generalized hydrogeologic section of the New Jersey Coastal Plain. (Modified from Martin, 1998)
6 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

DOWNDIP 

S A2 

C2 

A3 

C3 

A1 

C1 

S 

Atlantic Ocean S 

A4 

C4 

S 

A5 

C5 

P5 

S 

A6 

C6 

S 

P6 

S 

S 

P7 

S 

A7 

C7 

S 

A8 

C8 

S 

S A9 

C9 

A10 

UPDIP 

FALL LINE 

EXPLANATION 

A1 

C1 

AQUIFER-Number refers to model unit RECHARGE TO OUTCROP AREA OF AQUIFERlisted in table 2 Recharge rate greater than 1 inch per year 

CONFINING UNIT-Numbers refers to model unit RECHARGE TO OUTCROP AREA OF CONFING 

listed in table 2 UNIT-Recharge rate less than 1 inch per year 

S SURFACE-WATER STAGE NO-FLOW BOUNDARY 

STREAMBED OR LAKEBED CONDUCTANCE FLUX BOUNDARY


IN OUTCROP AREA


VERTICAL HYDRAULIC CONNECTION BETWEEN 

OUTCROP AREA OF CONFINING UNIT SIMULATED AS CONFINING UNITS--Aquifer is absent
 P5 AN AQUIFER LAYER-Number refers to model layer representing


the vertical flux through the confing-unit outcrop area


Figure 3. Schematic representation of aquifers, confining units, and boundary conditions used in the revised New Jersey Coastal 

Plain ground-water-flow model. (Modified from Martin, 1998, figure 4) 
Table 2. Geologic and hydrogeologic units of the New Jersey Coastal Plain and model units in the revised Regional Aquifer System

Analysis model

Original and Revised Model Designs 7 

Table 2. Geologic and hydrogeologic units of the New Jersey Coastal Plain and model units in the revised Regional Aquifer System 

Analysis model 

[Modified from Zapecza (1989, table 2) and Seaber (1965, table 3); shading indicates adjacent geologic or hydrogeologic unit is not defined; letter and number in 

parentheses is the model layer] 

SYSTEM SERIES GEOLOGIC UNIT HYDROGEOLOGIC 

UNIT 

Updip 

MODEL UNITS3 

Downdip 

Alluvial 

Quaternary 

Holocene deposits 

Beach sand 

and gravel 

Undifferentiated Upper Kirkwood-Cohansey aquifer (A2) 

Holly Beach water-bearing zone (A1) 

Pleistocene Cape May 

Formation 

KirkwoodCohansey1 

Estuarine Clay confining unit (C1) 

Upper Kirkwood-Cohansey aquifer (A2) 

Pennsauken Formation 

Bridgeton Formation 

Beacon Hill Gravel 

Cohansey Sand 

KirkwoodCohansey 

aquifer 

system Lower Kirkwood-Cohansey aquifer (A3) 

Miocene 

Potomac-RaritanMagothy Composite confining unit 

aquifer system 

Confining unit overlying the Rio Grande Confining unit water-bearing zone (C2) Kirkwood Formation


Rio Grande2
 Tertiary


Confining unit
 Confined Kirkwood aquifer (A3) 

Atlantic City 

800-foot sand 

Basal Kirkwood confining unit (C3) 

Oligocene Piney Point Piney Point Piney Point aquifer (A4) Formation aquifer 

Shark River


Formation
 Eocene Vincentown-Manasquan confining unit (C4) 

Manasquan Formation 

Vincentown Vincentown Formation Vincentown aquifer (A5) aquifer Paleocene


Hornerstown Sand


Tinton Sand


Red Bank
 Navesink-Hornerstown confining unit (C5) Red Bank Sand sand


Navesink Formation


Mount Laurel Sand
 Wenonah-Mount Laurel 

aquifer Wenonah-Mount Laurel aquifer (A6) Wenonah Formation


Marshalltown-Wenonah 
 Marshalltown-Wenonah confining unit (C6) Marshalltown Formation confining unit 

Englishtown aquifer Englishtown Formation Englishtown aquifer (A7) system 

Cretaceous 

Cretaceous 

Upper 

Woodbury Clay Merchantville-Woodbury 

Merchantville Formation
 confining unit Merchantville-Woodbury confining unit (C7) 

Upper
 Magothy Formation Upper Potomac-Raritan-Magothy aquifer (A8) aquifer 

Confining Confining unit between the Middle and Upper Potomac-Raritan-Magothy aquifers (C8) unit


Raritan Formation


Middle Middle Potomac-Raritan-Magothy aquifer (A9) aquifer 

Confining Confining unit between the Lower and Middle Potomac-Raritan-Magothy aquifers (C9) unit


Potomac Group
 Lower Lower Lower Potomac-Raritan-Magothy aquifer (A10) Cretaceous aquifer 

Pre-Cretaceous Bedrock Bedrock confining unit 

1

Kirkwood-Cohansey aquifer system. 

2

Rio Grande water-bearing zone. 

3

‘A’ refers to modeled aquifer. ‘C’ refers to modeled confining unit, number refers to model unit. 
8 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

400


350


300


250


1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000


for each stress period for each stress period 

Stress 

period 

1 

2 3 4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

Average withdrawals Total annual withdrawals 

YEAR 

Figure 4. Average and total annual ground-water withdrawals for each stress period for the New Jersey Coastal Plain, 

1968-98. WITHDRAWALS, IN MILLION GALLONS PER DAY 
9 

Lateral and Lower Boundary Conditions 

The model boundaries in the revised model are the same as 

those used in the 11-layer RASA model (plate 1). The model 

boundaries are shown in a cross section view in figure 3. A summary of the boundary conditions is given here. For a detailed 

discussion of the model boundaries and the different boundaries 

used for the 11-layer RASA model, refer to Martin (1998). 

The generalized lateral boundaries shown in plate 1 are not 

the same in every aquifer simulated in the model, but vary 

slightly among aquifers. The northwestern updip limit of all 

model layers is the limit of the Coastal Plain sediments, which 

is located at or within 15 mi of the Fall Line. The updip limit of 

the aquifers is modeled as a no-flow boundary. 

The Coastal Plain sediments overlie crystalline bedrock, 

and the lower boundary of the model is at this contact. It is 

likely that no flow occurs between the Coastal Plain sediments 

and the crystalline bedrock. This boundary also is modeled as a 

no-flow boundary. 

The lateral model boundaries in the northeast and southwest are specified-flux boundaries that originally were derived 

from a model of the North Atlantic Coastal Plain (Leahy and 

Martin, 1993) for the RASA model. For the model by Leahy 

and Martin, the model area extends from Long Island, New 

York, to North Carolina and includes all of the New Jersey 

Coastal Plain. The northeast and southwest boundaries roughly 

approximate a flow line, and specified fluxes were applied only 

in areas where the aquifer intersects the flow boundary. 

Flows at the lateral boundaries in the northeast and southwest for stress periods 1 to 3 are those used in the original 

RASA model. Flows at the lateral boundaries for stress periods 

4 to 21 for all aquifers, except the Potomac-Raritan-Magothy 

aquifer system for stress periods 19 to 21, were calculated by 

using the New Jersey Coastal Plain model constructed by Pope 

and Gordon (1999). Flows at the lateral boundaries in the Potomac-Raritan-Magothy aquifer system for stress periods 19 to 21 

also were calculated by using the model by Pope and Gordon 

(1999), except those at the Delaware and New Jersey boundary. 

Outward lateral fluxes were increased in those stress periods to 

reflect the large increase in ground-water withdrawals in Delaware. The increase in boundary flows was necessary to ensure 

that simulated water levels would match the water levels in the 

cone of depression that has developed in the Potomac-RaritanMagothy aquifer system at the Delaware and New Jersey State 

line since 1988. The lateral boundary flow for each stress 

period and the ground-water withdrawals for each aquifer are 

listed in table 3. 

The southeastern downdip boundary in the Potomac-Raritan-Magothy aquifer system is a stationary no-flow boundary 

and is located at the downdip limit of freshwater in the aquifer. 

The downdip limit of freshwater was determined by Meisler 

(1980) and is shown on the potentiometic-surface maps presented later in this report. 

The southeastern boundary in the confined Kirkwood 

aquifer and the upper Kirkwood-Cohansey aquifer is also a 

specified-flux boundary. The lateral boundary flows for stress 

Original and Revised Model Designs 

periods 1 to 3 are those used in the RASA model. The lateral 

boundary flows for stress periods 4 to 21 were calculated by 

using the New Jersey Coastal Plain model constructed by Pope 

and Gordon (1999). 

The Englishtown aquifer system and the Wenonah-Mount 

Laurel, Vincentown, and Piney Point aquifers (table 2) are not 

continuous throughout the New Jersey Coastal Plain. The limit 

of these aquifers in the southeast is modeled as a no-flow 

boundary. 

Upper Boundary Conditions 

The upper boundary of the model is a head-dependent-flux 

boundary in cells that represent the stream reaches in the model 

area. The stream stage was estimated from 1:24,000 USGS 

topographic maps of the model area. The streambed conductance was estimated as the product of the streambed hydraulic 

conductivity, length of stream reach, and stream width divided 

by the streambed thickness. The streambed conductance is an 

aggregate parameter that represents all of the factors that affect 

flow between the aquifer and the stream. 

In onshore areas, the upper boundary is a recharge boundary where all applied ground-water recharge flows downward 

through confining units and aquifers or laterally into aquifers. In 

offshore areas, the upper boundary is a constant freshwater 

equivalent water level. The recharge rate and stream stage were 

kept constant for all stress periods of the transient model. The 

recharge rate and stream stage are represented by long-term 

averages and do not reflect seasonal variations. The simulation 

of yearly hydrologic conditions with long-term averages for 

recharge and stream stage is consistent with the conceptual 

model that represents each stress period with average yearly 

hydrologic conditions. 

Streams 

A fine grid-cell size allows for a better representation of 

the streams in the model area. Because of the original large cell 

size in the RASA model, each cell represented at least one reach 

of a stream, and in many cells, various reaches of a stream were 

represented. Consequently, the stream stage for each original 

cell represented an average stage for a large reach of a stream or 

various stream reaches. The average stream stage in the new 

grid is for a stream reach with a maximum length of 4,226 ft, in 

contrast to 23,796 ft in the RASA grid. Model cells that represent the streams in the study area are shown in figure 5. Cells in 

the new grid that represent streams were identified by using 

geographic information system (GIS) coverages of the model 

grid (generated for this study) and streams (digitized from 

USGS 1:24,000 topographic maps). 

The drain and river packages of MODFLOW-96 were 

used to simulate the streams in the model area. The river package was used to simulate losing and gaining areas of the Delaware River and Raritan Bay. Continually gaining streams, 

located in other areas, were simulated with the drain package. 
Table 3. Average daily ground-water withdrawals from each aquifer and lateral boundary flows by stress period, New Jersey Coastal Plain, 19

Table 3. Average daily ground-water withdrawals from each aquifer and lateral boundary flows by stress period, New Jersey Coastal Plain, 19[All values are in million gallons per day. Positive boundary flows are out of model area, negative boundary flows are into model area.] 

Stress period 

Model layer 

number 

1 

1/1968 -

1/1973 

2 

1/1973 -

1/1978 

3 

1/1978 -

1/1981 

4 

1981 

5 

1982 

6 

1983 

7 

1984 

8 

1985 

9 

1986 

10 

1987 

A1 0.08 0.11 0.17 0.24 0.25 0.25 0.16 0.01 0.01 0.01 A2 38.93 43.87 48.57 60.06 57.85 61.77 64.07 74.55 80.69 77.38 A3 30.42 36.95 38.02 23.08 23.30 23.44 23.29 23.96 26.50 25.58 A4 1.48 1.97 2.00 1.81 2.02 1.97 1.79 1.77 2.12 2.01 A5 0.09 0.94 1.15 1.47 1.02 1.14 1.00 0.99 1.23 1.36 A6 4.65 4.56 4.97 4.65 4.66 6.05 6.07 6.28 6.84 6.50 A7 11.33 11.95 11.27 11.17 10.52 10.10 9.99 10.51 10.59 10.72 A8 85.93 84.79 85.44 81.99 85.91 87.39 81.24 81.58 83.15 81.52 A9 80.92 91.81 91.79 81.59 80.14 81.68 73.21 74.67 79.54 79.38 A10 71.83 73.95 74.82 76.41 74.34 79.67 74.17 75.20 69.34 67.25 

Total 325.66 350.9 358.2 342.47 340.01 353.46 334.99 349.52 360.01 351.71 3Net boundary flow -3.2 -5.2 -5.6 1.1 1.1 1.1 1.1 1.1 1.1 1.1 

Model layer 

A1 - Holly Beach water-bearing zone A2 - Upper Kirkwood-Cohansey aquifer A3 - Lower Kirkwood-Cohansey and confined Kirkwood aquifers A4 - Piney Point aquifer A5 - Vincentown aquifer A6 - Wenonah-Mount Laurel aquifer A7 - Englishtown aquifer system A8 - Upper Potomac-Raritan-Magothy aquifer A9 - Middle Potomac-Raritan-Magothy aquifer A10 - Lower Potomac-Raritan-Magothy aquifer 
Table 3. Average daily ground-water withdrawals from each aquifer and lateral boundary flows by stress period, New Jersey Coastal Plain, 19

Table 3. Average daily ground-water withdrawals from each aquifer and lateral boundary flows by stress period, New Jersey Coastal Plain, 19

Stress period 

Model layer 

number 

13 

1990 

14 

1991 

15 

1992 

16 

1993 

17 

1994 

18 

1995 

19 

1996 

20 

1997 

21 

1998 

A1 0.01 0.09 0.01 0.09 0.08 0.07 0.03 0.16 0.17 A2 83.00 95.63 95.30 83.43 93.73 100.70 83.53 112.10 105.14 A3 22.66 22.80 20.90 21.93 23.99 23.07 21.37 24.15 24.40 A4 1.87 2.23 2.29 3.32 3.25 2.89 3.60 3.81 4.50 A5 1.24 1.73 1.62 1.77 1.46 1.33 1.36 1.46 1.50 A6 6.56 6.16 6.33 6.78 6.39 7.72 6.31 10.19 9.15 A7 9.19 7.20 6.98 6.94 6.95 7.43 6.49 8.94 7.78 A8 73.94 72.22 69.38 68.28 66.38 66.19 59.04 62.64 67.26 A9 72.60 68.14 66.40 64.74 63.82 63.64 57.98 59.94 62.24 

A10 62.77 58.83 58.53 52.23 57.08 59.23 47.45 44.61 47.96 

Total 333.84 335.03 327.74 309.51 323.13 332.27 287.16 328.00 330.10 

Net boundary 

flow 0.4 0.4 0.4 0.4 0.4 0.4 0.9 0.9 0.9 

Model layer 

A1 - Holly Beach water-bearing zone A2 - Upper Kirkwood-Cohansey aquifer A3 - Lower Kirkwood-Cohansey and confined Kirkwood aquifers A4 - Piney Point aquifer A5 - Vincentown aquifer A6 - Wenonah-Mount Laurel aquifer A7 - Englishtown aquifer system A8 - Upper Potomac-Raritan-Magothy aquifer A9 - Middle Potomac-Raritan-Magothy aquifer A10 - Lower Potomac-Raritan-Magothy aquifer 
0 5 10 15 MILES

0 5 10 15 KILOMETERS

PENNSYLVANIA

MERCER

MIDDLESEX

MONMOUTH CAMDEN

GLOUCESTER SALEM

ATLANTIC

CAPE MAY

NEW YORK

ATLANTIC OCEAN DELAWARE BAY

RARITAN

BAY

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Cohansey River

De al ware R vi er

Raritan River

Navesink River

Manasquan River

Toms River

aB st ot R vi er

Mullica River

Maur ci e i R ev r

er G ggEt a

a H br uo Rr vi er

BURLINGTON

OCEAN

Location of stream reach in the outcrop area of model layer A1Location of stream reach in the outcrop area of model layer A2Location of stream reach in the outcrop area of model layer A3Location of stream reach in the outcrop area of model layer A5and the composite confining units simulated as part of modellayer A5Location of stream reach in the outcrop area of model layer A6and the Marshalltown-Wenonah confining unit simulated as part of model layer A6

EXPLANATION

MARYLAND

DELAWARE

75

39

40

75

74

74

39

Barnegat Light

Location of stream reach in the outcrop area of model layer A7and the Merchantville-Woodbury confining unit simulated as part of model layer A7Location of stream reach in the outcrop area of model layer A8Location of stream reach in the outcrop area of model layer A9Location of stream reach in the outcrop area of model layer A10

CUMBERLAND

12 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain

Figure 5. Model cells that represent stream reaches in the study area, New Jersey Coastal Plain.
Recharge 

The upper model boundary includes a spatially variable 

recharge rate applied at cells that represent the outcrop area of 

aquifers and confining units without wetlands. The recharge 

rate applied to the outcrop areas represents long-term precipitation minus long-term evapotranspiration and surface-water runoff. The amount of precipitation that results in surface-water 

runoff is related to the topography and lithology of the outcrop 

areas. The spatially variable recharge rate reflects these changes 

in the outcrop areas of eight aquifers and three confining units 

in the Coastal Plain. The Piney Point aquifer, the Lower Potomac-Raritan-Magothy aquifer, the Estuarine Clay confining 

unit, and the confining unit overlying the Rio Grande waterbearing zone (table 2) do not crop out in the model area and 

receive no recharge at the upper model boundary. The confining 

unit between the Middle and Upper Potomac-Raritan-Magothy 

aquifers and the confining unit between the Lower and Middle 

Potomac-Raritan-Magothy aquifers either crop out under the 

Delaware River or are simulated as receiving no recharge at the 

upper model boundary because the width of the outcrop area is 

negligible, less than 0.5 mi. Zapecza (1989) does not map an 

outcrop area for these confining units. Barton and Kozinski 

(1991) and Lewis and others (1991) show these units to have 

limited outcrop areas, less than 0.5 mile wide in their respective 

study areas. 

The precipitation that recharges the outcrop areas eventually flows to surface-water bodies, such as streams or the ocean, 

and is referred to as ground-water discharge. Ground-water discharge can be local flow to nearby streams within the shallow 

aquifer system, intermediate flow along long flow paths (miles) 

beneath nearby streams that discharge to neighboring larger 

streams, or regional flow that moves through confining units to 

confined aquifers and eventually discharges to large rivers and 

(or) the ocean. 

Model Calibration 

The revised model was calibrated by trail-and-error adjustment of the vertical-leakance values, storage-coefficient values, 

streambed-conductance values, lateral-boundary fluxes, and 

recharge rates. Recharge rates were adjusted in areas where no 

previous studies were conducted that determined a recharge 

rate. During model calibration, it was found that changes to only 

the five model parameters listed above improved the RASA 

model calibration in any particular area; therefore, these parameters were changed from the RASA model-input data. These 

five parameters were adjusted during model calibration in order 

to minimize the difference between simulated and measured 

values of one or more of the following: (1) estimated base flow 

for five river basins, (2) water levels in 28 selected observation 

wells for which long-term hydrographs were available, and (3) 

potentiometric surfaces for 1978, 1983, 1988, 1993, and 1998 

conditions. 

Model Calibration 13 

Simulated 1978 potentiometric surfaces from the RASA 

and revised model also were compared during model calibration. The objective of comparing the simulated potentiometric 

surfaces from the RASA model and revised model was to 

ensure that the original level of calibration was maintained or 

improved. 

Revisions to Model Input Data 

In the following four sections, the revisions to the modelinput data for the revised model are described. 

Recharge 

The recharge rates are based on values determined by studies conducted in the New Jersey Coastal Plain and by model calibration. The recharge rates are shown in figure 6, and the locations of the study areas are shown in figure 7. The recharge rates 

range from 0.01 in/yr in the outcrop area of the composite confining unit to 20 in/yr in the Cohansey aquifer. The recharge 

rates used in this model are long-term averages and regional 

estimates. These rates do not reflect seasonal or local variations, 

which do occur. 

Recharge was applied to the modeled outcrop area of three 

confining units because, on the basis of simulation results, a 

small amount of recharge could be percolating through the confining units to the underlying aquifers. Recharge to confiningunit outcrops could not be simulated directly because confining 

units are not represented with a layer of cells in the model, but 

only with vertical-leakance characteristics. Therefore, recharge 

to confining-unit outcrops is applied to cells with zero transmissivity in the layer that represents the overlying aquifer. The outcrop areas of confining units C5, C6, and C7 are labeled p5, p6, 

and p7, respectively, in figure 3 and are simulated as part of the 

aquifer overlying the confining unit. For example, the confining 

unit outcrop area labeled p5 is simulated as part of the aquifer 

labeled a5. In these areas (p5, p6, and p7 in figure 3), no horizontal flow to the aquifer results, only vertical flow through the 

outcrop area of the confining unit to the underlying aquifer. 

Vertical Leakance 

The vertical leakance was adjusted for the Navesink-Hornerstown confining unit (fig. 8). The vertical-leakance values 

were decreased a maximum of three orders of magnitude in the 

vicinity of the wells shown in figure 8, which are screened in the 

Vincentown and Wenonah-Mount Laurel aquifers, to obtain a 

better match between the simulated and long-term measured 

water levels in these wells. Simulated water levels for well 29-

139, which is screened in the Vincentown aquifer, are 6 ft closer 

to measured water levels in 1978 than in the original RASA 

model. Simulated water levels in well 25-486, which is 

screened in the Wenonah-Mount Laurel aquifer, are 15 ft closer 

to measured water levels in 1985 than in the original RASA 

model. All other vertical-leakance values used in the revised 
0 5 10 15 MILES

0 5 10 15 KILOMETERS

01408500

01465850

01467000

01477120

01482500

PENNSYLVANIA

NEW YORK

ATLANTIC OCEAN DELAWARE BAY

RARITAN

BAY

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Cohansey River

De al ware R vi er

Raritan River

Navesink River

Manasquan River

Toms River

aB st ot R vi er

Mullica River

Maur ci e i R ev r

er G ggEt a

a H br uo Rr vi er

Recharge rate, in inches per year

EXPLANATION

MARYLAND

DELAWARE

75

39

40

75

74

74

39

Barnegat Light

Point Pleasant

Boundary of drainage basin drainingto streamflow-gaging stationStreamflow-gaging station and number

01482500

0.010.869

15161720

14 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain

Figure 6. Recharge rates used in the model and the location of selected drainage basins and streamflow-gaging stations in the model area, New Jersey Coastal Plain.
Model Calibration 15 

75 

41 

40 

39 

74 

0 

0 

10 

10 

SALEM 

CUMBERLAND 

GLOUCESTER CAMDEN 

CAPE 

OCEAN 

MONMOUTH 

MERCER MIDDLESEX

SOMERSET 

NEW JERSEY 

HUDSON 

HUNTERDON 

SUSSEX 

MORRIS 

BERGEN 

ESSEX 

UNION 

D E LAW ARE 

R IVE R 

FALL LINE 

Hydrology of the unconfined aquifer system, 

5 sheets. 

Hydrogeology of the unconfined aquifer 

Resources Investigations Report 94-4234, 

6 sheets 

unconfined aquifer system of the Great Egg Harbor River basin, 

Investigations Report 91-4126, 5 pls. 

Charles, E.G., Storck, D.A., and Clawges, R.M., 2001, 

Hydrogeology of the unconfined aquifer system, Maurice River 

Johnson, M.L., and Charles, E.G., 1997, 

Hydrogeology of the unconfined aquifer system, 

Salem River area: Salem River and Racoon, 

O

J

Resources Investigations Report 96-5195, 5 sheets 

Hydrology of the unconfined aquifer 

system in the upper Maurice River basin 

20 MILES 

20 KILOMETERS 

ATLANTIC 

BURLINGTON 

MAY 

PASSAIC 

WARREN 

Watt, M.K., Johnson, M.L. and 

Lacombe, P.J., 1994 

Toms River, Metedeconk River, and Kettle 

Creek Basins, New Jersey, 1987-90: 

U.S. Geological Survey WaterResources Investigations Report 93-4110, 

Johnson, M.L., and Watt, M.K., 1996, 

system, Mullica River Basin, New Jersey, 

1991-92: U.S. Geological Survey WaterWatt, M.K. and Johnson, M.L., 1992, Water resources of the 

New Jersey, 1989-90: U.S. Geological Survey Water-Resources 

ldmans, Alloway, and Stow Creek Basins, New 

ersey, 1993-94: U.S. Geological Survey WaterLacombe, P.J. and Rosman, R., 1995, 

and adjacent areas in Gloucester County, 

New Jersey, 1986-87: U.S. Geological Survey 

Water-Resources Investigations Report 92-4128, 

Watt, M.K., Kane, A.C., Charles, E.G., 

and Storck, D.A., 2003, Hydrology of the 

unconfined aquifer system, Rancocas 

Creek area: Rancocas, Crosswicks, 

Assunpink, Blacks, and Crafts Creek Basins, 

New Jersey, 1996: U.S. Gelogical Survey 

Water-Resources Investigations Report 

02-4280, 5 sheets 5 sheets 

Spitz, F.J., 1998, Analysis of ground-water flow and saltwater area: Maurice and Cohansey River basins, New Jersey, 1994-95: encroachment in the shallow aquifer system of Cape May County, U.S. Geological Survey Water-Resources Investigations Report New Jersey: U.S. Geological Survey Water-Supply Paper 2490, 01-4229, 5 sheets 51 p. 

Figure 7. Location of, and references for, studies that reported ground-water recharge rates in the New Jersey Coastal Plain. 
29-138

25-637

25-429

25-486

25-353

0 5 10 15 MILES

0 5 10 15 KILOMETERS

PENNSYLVANIA

MERCER

MIDDLESEX

MONMOUTH

CAMDEN

GLOUCESTER SALEM

ATLANTIC

CAPE MAY

NEW YORK

ATLANTIC OCEAN DELAWARE BAY

RARITAN

BAY

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Cohansey River

De al ware R vi er

Raritan River

Navesink River

Manasquan River

Toms River

aB st ot R vi er

Mullica River

Maur ci e i R ev r

er G ggEt a

a H br uo Rr vi er

BURLINGTON

OCEAN

1 x 10E to 5 x 10E5 x 10E to 5 x 10E5 x 10E to 5 x 10E

EXPLANATION

MARYLAND

DELAWARE

75

39

40

75

74

74

39

Barnegat Light

CUMBERLAND

5 x 10E to 5 x 10E5 x 10E to 5 x 10E5 x 10E to 5 x 10E

Location of well and well number

Interval, in feet per day per foot, is variable

-11

-8

-7

-10

-7

-6

-6 -5

-4

-3

-5-4

25-637

VERTICAL LEAKANCE

16 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain

Figure 8. Vertical leakance used in the model for the Navesink-Hornerstown confining unit and location of selected wells in the study area, New Jersey Coastal Plain.
Model Calibration 17 

model are from the original RASA model. The simulation of 

long-term water levels is presented in the “Simulated and Measured Water-Level Hydrographs” section. 

Storage Coefficient 

A storage coefficient of 0.0001 was used in the RASA 

model for most areas of confined aquifers. The exceptions are 

the downdip areas of the three Potomac-Raritan-Magothy aquifers in Monmouth and Ocean Counties, where storage coefficients ranging from 5 x 10-4 to 8 x 10-4 were used. A better 

match was achieved with a storage coefficient of 0.001 between 

simulated and measured water levels at well 25-486 screened in 

the Wenonah-Mount Laurel aquifer. Water levels in the 

Wenonah-Mount Laurel aquifer and Englishtown aquifer system in Critical Water Supply Area 1 (fig. 1) have risen more 

than 100 ft since 1988 as a result of the decrease in groundwater withdrawals. During model calibration, it was found that 

storage coefficient is an important parameter in the recovery of 

water levels in this area. 

The simulated water levels for well 25-486 (fig. 9) result 

from two model scenarios, one with a storage coefficient of 

0.001 and the other with 0.0001. Simulated water levels that 

result from a storage coefficient of 0.0001 initially matched 

measured water levels at well 25-486 but began to diverge with 

the decrease in withdrawals in 1989. It appears that ground 

water flowing into this area is expanding the aquifer material 

and (or) is being compressed (water levels not increasing) rather 

than increasing water levels. 

During model calibration, the simulated recharge rate in 

the Wenonah-Mount Laurel aquifer outcrop area was increased 

and decreased without any effect on the water levels in the cone 

of depression in the Wenonah-Mount Laurel aquifer located in 

the Point Pleasant, Ocean County, N.J., area (fig. 6). The transmissivity of the Wenonah-Mount Laurel aquifer is low, from 

500 to 1,000 ft2/d. Because of the low transmissivities, 

recharge water that enters at the outcrop area does not flow 

downdip. An increase or decrease of the transmissivities of the 

Wenonah-Mount Laurel aquifer resulted in simulated water levels that were higher or lower than measured water levels in 

wells in this area (fig. 9). An increase or decrease of the transmissivities also resulted in simulated water levels that did not 

match the curve of the hydrograph of measured water levels 

shown in figure 9. 

The vertical leakance of the confining units that overlie 

(Navesink-Hornerstown) and underlie (MarshalltownWenonah) the Wenonah-Mount Laurel aquifer also was 

changed during model calibration. An increase or decrease of 

the vertical leakance of the Marshalltown-Wenonah confining 

unit resulted in simulated water levels that were too high or too 

low in the Wenonah-Mount Laurel aquifer. A decrease of the 

vertical leakance of the Navesink-Hornerstown confining unit 

resulted in a better match with the measured water levels prior 

WATER LEVEL, IN FEET BELOW NGVD OF 1929


-25 

-50 

-75 

-100 

-125 

-150 

-175 

-200 

0 

Measured water level 

Simulated water level that result from 

Simulated water level that result from 

a storage coefficient of 0.001 

a storage coefficient of 0.0001 

1984 1986 1988 1990 1992 1994 1996 1998 

YEAR 

Figure 9. Hydrographs of measured and simulated water levels in well 25-486 screened in the Wenonah-Mount Laurel 

aquifer that result from two model scenarios with storage coefficients of 0.001 and 0.0001, New Jersey Coastal Plain, 1985-98. 

(Well location shown in fig. 22)
18 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

to the decrease in ground-water withdrawals that began in 1989. 

Simulated water levels after 1990 for the scenario with a storage 

coefficient of 0.0001 were as much as 83 ft higher than measured water levels (1991). Again, all of these simulations 

resulted in water levels that did not match the curve of the 

hydrograph of measured water levels shown in figure 9. The 

measured water levels in well 25-486 have been increasing 

since 1989 (fig. 9), which indicates that water levels have not 

reached steady-state conditions. 

Boundary Fluxes 

To simulate the eastern part of a regional cone of depression that has developed around wells in the Lower PotomacRaritan-Magothy aquifer in Delaware, boundary fluxes near the 

Delaware and New Jersey State line were adjusted during 

model calibration until a reasonable match was achieved 

between the measured and simulated water levels in this area in 

1998. The fluxes at this boundary were increased 0.5 Mgal/d 

from the 4.1 Mgal/d used in the original RASA model for the 

Lower Potomac-Raritan-Magothy aquifer. An increase of 0.5 

Mgal/d at this boundary is less than 0.001 percent of the outflow 

of the entire model area for 1995. 

The total 1997 ground-water withdrawals from the Lower 

Potomac-Raritan-Magothy aquifer in Delaware was 

5.42 Mgal/d (Lacombe and Rosman, 2001). The location of 

these withdrawal wells shown in figure 10 is just beyond the 

active model area. The increased boundary fluxes at the Delaware-New Jersey boundary represent part of the ground-water 

withdrawals from these wells. 

Simulated Potentiometric Surfaces 

During model calibration, the simulated potentiometric 

surfaces were compared to those from each of the five Coastal 

Plain synoptic studies conducted in 1978, 1983, 1988, 1993, 

and 1998 to ensure that cones of depressions and flow directions 

were simulated throughout the time periods of the study. Discussion of the potentiometric surfaces in this report is limited to 

1978 and 1998 ground-water-flow conditions. The interpreted 

1978 potentiometric surfaces also were compared to simulated 

transient-model results to ensure that the same level of calibration was maintained or improved with the revised model. 

Hydrologic conditions for 1998 are discussed in this report 

because the 1998 water-level synoptic study provides the most 

recent water-level data. 

1978 Ground-Water-Flow Conditions 

In most areas of each aquifer the interpreted and simulated 

1978 potentiometric surfaces compare well, and the level of calibration was maintained or improved. Martin (1998) presents a 

lengthy discussion of the comparison of the simulated and interpreted potentiometric surfaces, which still is valid for the 

revised model. 

The simulated potentiometric surfaces from the RASA 

model and the revised model also compare well. The only minor 

difference in the calibration of the two models is in the cone of 

depression centered in Point Pleasant, N.J., in the WenonahMount Laurel aquifer and Englishtown aquifer system. The 

revised model simulates the potentiometric surfaces in the cone 

of depression in this area to be about 20 and 40 ft, respectively, 

deeper than those of the RASA model. The 1978 interpreted 

potentiometric surfaces (potentiometric surfaces constructed 

with measured water levels) in the cones (Walker, 1983) in this 

area are about 180 and 240 ft below NGVD of 1929, respectively; these potentiometric surfaces compare well with the simulated potentiometric surfaces from the revised model (fig. 11), 

which are about 160 and 220 ft below NGVD of 1929, respectively. The improvement in the agreement of water levels is 

because of the smaller grid spacing and the change in the vertical leakance values of the confining unit overlying the 

Wenonah-Mount Laurel aquifer. 

1998 Ground-Water-Flow Conditions 

The simulated and, when available, interpreted potentiometric surfaces for 1998 are shown in figures 12-21. During the 

1998 Coastal Plain water-level synoptic study (Lacombe and 

Rosman, 2001), no water levels were measured in the Holly 

Beach water-bearing zone, upper Kirkwood-Cohansey aquifer 

system, or Vincentown aquifer. In general, the interpreted and 

simulated water levels match closely; in most areas they are 

within 20 ft. The exceptions are in the cone of depression in the 

Piney Point, Wenonah-Mount Laurel, and Upper PotomacRaritan-Magothy aquifers. 

Water levels in the Piney Point aquifer simulated with the 

RASA model matched measured water levels closely except in 

the southwestern Coastal Plain and along the Atlantic Coast 

(Martin, 1998). Martin states that there were few measured 

water levels available for the Piney Point aquifer and further 

calibration of the model in this area was not beneficial. Waterlevel data for the Piney Point aquifer still are sparse. The aquifer 

was not a focus of this current study, and no attempt was made 

to match measured and simulated water levels with the revised 

model more closely. The same level of calibration is maintained, however. The maximum difference (40 ft) between 1998 

simulated and measured water levels is in the small cone of 

depression centered near Barnegat Light, N.J. (fig. 15). 

The shape and depth of the two small cones of depression 

located in the Wenonah-Mount Laurel aquifer in Burlington 

County were not simulated as closely to measured water levels 

as those in other areas of the aquifer (fig. 17). The difference 

between the measured and simulated water levels in the cone of 

depression in northwestern Burlington County is about 40 ft. 

The difference between the measured and simulated water levels in the cone of depression in northeastern Burlington County 

is about 20 ft. The poor match between the simulated and measured water levels could be due to contouring style and (or) 
Model Calibration 19 

75 53’42" 75 46’39" 75 39’36" 75 32’33" 75 25’30" 75 18’27" 

39 

50’ 

15" 

39 

43’ 

12" 

39 

36’ 

09" 

39 

29’ 

06" 

NEW JERSEY 

MARYLAND 

DELAWARE 

DELAWARE RIVER 

DELAWARE 

BAY 

PENNSYLVANIA 

Base from U.S. Geological Survey digital data,


1:100,000, 1983, Universal Transverse Mecator


Projection, Zone 18 0 4 8 MILES


0 10 KILOMETERS 

EXPLANATION 

Location of ground-water withdrawl well 

Figure 10. Location of ground-water withdrawal wells screened in the Lower Potomac-Raritan-Magothy aquifer in Delaware, 1997. 
PENNSYLVANIA

MERCER

MIDD

MON

ATLANTI

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Delaware River

Ma

Toms River

Batsto River

Mullica

BURLINGTON

OCEAN

75

39

30’

40

75

Barnegat Light

River

Point 

UPDIP LIMIT OF AQUIFER

120

40

20

100

40

40

60

80

60

40

20

0

100

20

40

40

60 60

40

-160

-180

80

60

40

20

-20

20

120 100

0

-60

-80

-1

-180

-

-200

80

-40 

0 5 10 15 MILES

0 5 10 15 KILOMETERS

-20

-40

-80

-120

-140

-160

40 20

0

120

120

40

60

120

80

60

40

20

0

100120

80

60

40

20

20

0

-20

20

140

120

100

80

0

0

-20

-40 -60

-80

-140

-100

-120

-140

-160

-180

PENNSYLVANIA

MERCER

MIDDLESEX

MONMOUTH

NEW YORK

ATLANTIC OCEAN

RARITAN

BAY

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Delaware River

Raritan River

Navesink River

Manasquan River

Toms River

Batsto River

Mullica

BURLINGTON

OCEAN

SIMULATED POTENTIOMETRIC CONTOUR--Shows simulated altitude stood in tightly cased wells. December 1978. Contour interval 20 and 40 INTERPRETED POTENTIOMETRIC CONTOUR--Shows interpreted altitstood in tightly cased wells. Dashed where approximate. Modified from W40 feet. Datum is NGVD of 1929

EXPLANATION

75

39

30’

40

75

74

20

20

Barnegat Light

River

Point Pleasant

(a) (b)

U

P

DIP LIMIT

O

F

AQUIFE

R

D

OW

N

DIP LIMIT

OF A

Q

UIFER

MODEL BOUNDARY

Figure 11. Simulated and interpreted potentiometric surfaces of the (a) Wenonah-Mount Laurel aquifer, (b) Englishtown aquifer system, New Jersey Coasta
4 

Model Calibration 21 

5 

74 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH CAMDEN 

GLOUCESTER SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN BAY 

Cohans e y R i v e r 

De al ware 

R vi er R a r itan Riv e r 

Navesink River Ma n a s q u a n 

R i v e r 

To m s 

R i v e r 

aB st ot R vi er 

M u l li c a 

R i v e r Maur ci e

i R

ev r 

er G

ggE

t

a

a H

br

uo

Rr vi er 

BURLINGTON 

OCEAN

SIMULATED WATER-TABLE CONTOUR--Showssimulated water table, December 1998. Contourinterval 5 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND DELAWARE 

75

39 

40 7

7

39 

5 

Barnegat Light 

L MI TI OF AQU FI ER

CUMBERLAND

5

10 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Figure 12. Simulated water table of the Holly Beach water-bearing zone, New Jersey Coastal Plain, 1998. 
5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

-10 

0 

0 

0 

0 0 

0 

0 

0 

20 0 

60 

0

100 

120 

60 

60 

140 

100 120 

60 

20 

20 

0 

60 

100 

140 

60 

60 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN

SIMULATED WATER TABLE CONTOUR--Showsaltitude of simulated water table and potentiometricsurface December 1998. Contour interval is variable.Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

74 

39 

20 

Barnegat Light 

MODEL BOUNDARY 

UPDIP LIMIT OF OVERLYING CONFINING UNIT 

UPDIP LIMIT OF AQUIFER 

CUMBERLAND 

22 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 13. Simulated water table and simulated potentiometric surfaces of the upper Kirkwood-Cohansey aquifer system, New Jersey Coastal Plain, 1998. 
Model Calibration 23 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

0 

20 

60 

120 

60 

60 

60 

60 

60 

0 

20 

0 

-20 

-40 -80 

-70 

-60 

-50 

-40 

120 

0 

-20 

60

140 

120 

100 

180 

160 

140

120 

140 

100

120 

140

60 

60 

60 140 

0 

0 

100 

100 

20 

60 

0 

-40 

-60 

-100 

-80 

-60 

-40 

-20 

0 

0 20 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH CAMDEN 

GLOUCESTER SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a vesink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 2001. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

74 

39 

20

20 

Barnegat Light 

UPDIP LIMIT OF AQUIFER

MODEL BOUNDARY 

UPDIP

LIMIT 

OF O

VERLY

NI G

CONF

NI NI G

UN

T I

CUMBERLAND 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 14. Siimulated and interpreted potentiometric surfaces of the lower Kirkwood-Cohansey aquifer system and confined Kirkwood aquifer, New Jersey Coastal Plain, 1998. 
24 

5 

74 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH CAMDEN 

GLOUCESTER SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN 

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

7

39 

20

20 

Barnegat Light 

CUMBERLAND 

MODEL BOUNDARY 

DOWNDIP LIMIT OF AQUIFER 

UPDIP LIMIT

OF AQUIFER 

60 

100 

80 

-20 

40 

60 

120 

20 

0 

-60 

-40 

-20 

-20 

-20 

-40

-60 

-20 

-20 

0 

60 

40 

20 

0 

-20 

0 

-40 

-20

-40

-20

-60 

120

100 

80 

60 

-40 

-60 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Figure 15. Simulated and interpreted potentiometric surfaces of the Piney Point aquifer, New Jersey Coastal Plain, 1998. 

4 

Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 
4 

Model Calibration 25 

5 

74 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

40 

60 

40 

20 

10

10

10 

60

80 100

80

60 40 

40

20 

40 

120

100 

40 

60

80 

80 

100 

120

160 

140 

120 

100 

80 60 

40 

20 

100 

80 

80 60 

20

10 

60 

40 

20 

140 

100 

120

100 

80 

60 

80

60 

40 

100 

80 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER 

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN 

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

7

39 

20

20 

Barnegat Light 

MODEL BOUNDARY 

D

OW

N

D P I L MI T I OF A

QU FI ER 

UPDIP LIMIT OF AQUIFER 

CUMBERLAND 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980

Figure 16. Simulated and interpreted potentiometric surfaces of the Vincentown aquifer, New Jersey Coastal Plain, 1998. 
26 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN GLOUCESTER 

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

M a n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN 

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

74 

39

20

20 

Barnegat Light 

MODEL BOUNDARY 

UPDIP LIMIT OF AQUIFER 

DOWNDIP LIMIT 

OF AQUIFER 

CUMBERLAND 

0 

40 

40 

40 

20 

20

40 

40 

20 

0

30

20 

20

60 40

80 

60 

40 

20 20 

40 

60 

120 

100 

120 

100 

80 

60 

0 

0 

20 

40 

-20 

-30 

-40 

-40 

-50 

-50 

-60 

-80 

0 

0

60 60 

-40

-20 

-60 -40

40 

20 

-20 

-40 

0

60 

80 

120 

100 

60 

20 

-20 

0 

140 

120 

100 

80 

60 

40

20 0 

-20 

-40 

-60

-80 

-80 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 17. Simulated and interpreted potentiometric surfaces of the Wenonah-Mount Laurel aquifer, New Jersey Coastal Plain, 1998. 
Model Calibration 27 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER 

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

Raritan River 

N a v e sink River 

M a n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a 

a H br uo Rr vi er 

BURLINGTON 

OCEAN

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

74 

39 

20

20 

Barnegat Light 

MODEL BOUNDARY 

UPDIP LIMIT OF AQUIFER 

DOWNDIP LIM T I OF AQU FI ER CUMBERLAND 

40 

20 

40 

20 

4020

20 

40 40 40 

20 

60

40

0 

20

60 

60 60 

0 

40 

60 

40 

20 

40 

40

40 

60 40 

60 120 

100

100 

80 

60 

40 

20 

0 

-20 

-40

-60 

-80 

-100 

80 

80 

0 

60 40 

20 

80 

0 

0 

60

40 

20 

40 

40 

100 

80

60 

20 

0 -20 

-40 

-80 

-60 

-100 

-80 

-100 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 18. Simulated and interpreted potentiometric surfaces of the Englishtown aquife system, New Jersey Coastal Plain, 1998. 
28 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN 

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

74 

39 

20

20 

Barnegat Light 

MODEL BOUNDARY 

UPDIP LIMIT OF AQUIFER 

CUMBERLAND 

APPROXIMATE SEAWARD LIMIT OF FRESHWATER IN LOWER POTOMAC-RARITAN-MAGOTHY AQUIFER AS DELINEATED BY CHLORIDE CONCENTRATION 

OF 10,000 MILLIGRAMS PER LITER 

0 

0 0 

-50

-60

-70 

-70

-40 80 60 

40 

20 

20 

0 

60 

40 

0 

-20 

-40 

-40 

-40

-20 

-20 

0 

-20 

-60 

-80 

-80

-100 

-40 

-40 

-20 

0 

0 

-20 

60 

40 

20 

0 

-20 

-20 

-60 

-20 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 19. Simulated and interpreted potentiometric surfaces of the Upper Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1998. 
Model Calibration 29 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

Ma n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN 

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75 

40 

7

74 

39 

20

20 

Barnegat Light 

CUMBERLAND 

MODEL BOUNDARY 

UPDIP LIMIT OF AQUIFER

APPROXIMATE SEAWARD LIMIT OF FRESHWATER IN 

LOWER POTOMAC-RARITAN-MAGOTHY AQUIFER 

AS DELINEATED BY CHLORIDE CONCENTRATION 

OF 10,000 MILLIGRAMS PER LITER 

-20 

-40 

-20 

-20 

-20 

-50 

-60

-40 

0 

-20 

20 40 

40 

60

80 

80 

100 

80 

60 

60 

40 

20 

20 

-40 

60 40 20 

-40 

-20 

-40 

-20 

-60 

-40 -60 

-60 

0 

0 

20 

40 

60 

-20 

-20 

-40 

-20 

0 

-20 

74 Base from U.S. Department of Agriculture

Soil Conservation Service, 1:250,000, 1980

Figure 20. Simulated and interpreted potentiometric surfaces of the Middle Potomac-Raritan-Magothy aquifer, New Jersey Coastal Plain, 1998. 

39 
5 

30 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

4 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH CAMDEN 

GLOUCESTER 

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohan s e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

N a v esink River 

M a n a s q u a n R i v e r 

T o m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON OCEAN

SIMULATED POTENTIOMETRIC CONTOUR--Showssimulated altitude at which water level would havestood in tightly cased wells. December 1998. Contourinterval 20 feet. Datum is NGVD of 1929INTERPRETED POTENTIOMETRIC CONTOUR--Showsinterpreted altitude at which water level would havestood in tightly cased wells. Dashed where approximate.Modified from Lacombe and Rosman, 1998. Contourinterval 20 feet. Datum is NGVD of 1929

EXPLANATION 

MARYLAND

DELAWARE 

75 

40 

7

7

39 

20 

20 

Barnegat Light 

CUMBERLAND 

MODEL BOUNDARY 

UPDIP LIMIT OF AQ UIFER 

APPROXIMATE SEAWARD LIMIT OF FRESHWATER IN 

LOWER POTOMAC-RARITAN-MAGOTHY AQUIFER 

AS DELINEATED BY CHLORIDE CONCENTRATION 

OF 10,000 MILLIGRAMS PER LITER 

-60 

-50 

-40 

-20 

0 

0 

-40

-50 

-60

-80 

-20 

-20 

-60 

-40

-60

-40

-80 

-120

-100 

-20 

-20 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 21. Simulated and interpreted potentiometric surfaces of the Lower Potomac-Raritan-Magothy aquifer, New Jersey Coastal plain, 1998. 

39 
unreported ground-water withdrawals. The NJDEP does not 

require that ground-water withdrawals less than 100,000 gal/d 

be reported. The Wenonah-Mount Laurel aquifer has low transmissivity values (500 to 1,000 ft2

/d), and during model calibration, water levels in the aquifer were found to be sensitive to 

ground-water withdrawals. Unreported ground-water withdrawals that are not simulated in the model could cause simulated water levels to be higher than measured levels. 

The simulated water levels in the Upper Potomac-RaritanMagothy aquifer are as much as 35 ft higher than measured 

water levels in the cone of depression centered in Camden 

County (fig. 19). The 1998 simulated water levels were within 

10 and 15 ft of measured water levels in wells 5-258 and 7-477 

(fig. 22), respectively, which are located on the flanks of this 

regional cone of depression. Water levels in well 5-258 initially 

were simulated more closely, within 3 ft of the measured water 

levels. The difference between the simulated and measured 

water levels increased beginning in 1983. Determining the specific cause of these differences is beyond the scope of this study. 

Simulated and Measured Water-Level Hydrographs 

Long-term hydrographs were plotted for the 28 selected 

wells shown in figure 22; these hydrographs were used during 

model calibration. The wells were selected on the basis of location and period of record. Also, when possible, wells used by 

Martin (1998) were selected. Some of the wells with hydrographs that Martin used during model calibration are no longer 

monitored; when possible, a nearby well, for which a 

hydrograph is available, was selected.

 Hydrographs of simulated and measured water levels for 

the 28 wells are shown in figures 23-49. In general, the simulated water levels are within 25 ft of the measured water levels 

and, in most cases, are within 5 ft. 

Wells 1-834, 7-283, 7-477, 7-478, 11-96, and 33-251, 

which have the greatest differences between simulated and 

measured water levels, are located near regional cones of 

depression (fig. 22). The large differences between the simulated and measured water levels could be due to the discretization scale of the model area and (or) unreported ground-water 

withdrawals. Simulated water levels are an average for each 

model cell. 

Differences in measured water levels among aquifers were 

compared to differences in simulated water levels at five well 

clusters located throughout the New Jersey Coastal Plain. The 

location of well clusters is shown in figure 22. Each well cluster 

consists of at least two wells in close proximity, screened in two 

different aquifers. Three of the five well clusters consist of four 

wells in close proximity; one well is screened in the outcrop 

area of an aquifer where unconfined conditions are present, and 

the other three wells are screened in different confined aquifers. 

Evaluation of the water-level differences among aquifers 

showed that the direction of flow between confined aquifers and 

the water table is simulated accurately. 

Model Calibration 31 

Base Flow 

The simulated and estimated base flows at continuousrecord streamflow-gaging stations in the Toms River, North 

Branch Rancocas Creek, South Branch Rancocas Creek, Raccoon Creek, and Salem River drainage basins are listed in table 

4, and the location of the sites is shown in figure 6. These basins 

were selected because a detailed analysis of base flow was 

available for each of the rivers and because each river is representative of typical rivers in the New Jersey Coastal Plain. The 

estimated base-flow values listed in table 4 are the mean base 

flows for the time period shown in the table. The interval for the 

calculated mean base flow ranges from 26 to 68 years. The values listed in table 4 for the simulated base flow are the average 

for the interval of the simulation, 1968–98, from the transient 

model. The base flow for each river and stress period was calculated. The values were added, then divided by 21, the number 

of stress periods. The resulting value is the simulated mean 

annual base flow. 

The simulated and calculated mean base flow in the five 

river basins compare well; all differences are less than 31 percent. The simulated and calculated base flow at continuousrecord streamflow gaging stations Toms River (01408500) and 

North Branch Rancocas Creek (01467000), the two large 

basins, match closely, within 10 percent. Differences are larger 

between the simulated and calculated base flow at Raccoon 

Creek (01477120) and Salem River (01482500), the two small 

basins, 31 and 27 percent, respectively. 

Model Limitations 

This revised model of the New Jersey Coastal Plain sediments is a tool for analysis of the regional ground-water-flow 

system. All models are an approximation of the actual groundwater-flow system. Ground-water-flow models generally are 

based on conceptual models that are simplified representations 

of complex heterogeneous systems. Assumptions such as isotropy and vertical homogeneity within each layer are examples 

of simplified representation that can be a source of simulation 

errors. Local scale heterogeneities or hydrologic features not 

represented in the model may affect results. Model parameters 

were estimated in areas where there is a lack of data, such as 

water-level measurements. Model parameters, such as transmissivity, ground-water withdrawals, and recharge rates, represent averages for areas that range from 0.25 mi2 to 0.32 mi2

. 

Local features, such as the maximum depth of a cone of depression, are not simulated with the revised model. Water levels that 

result from seasonal variations in ground-water withdrawals or 

recharge rates also are not simulated. 
32 

5 

0 5 10 15 MILES 

0 5 10 15 KILOMETERS 

PENNSYLVANIA 

MERCER 

MIDDLESEX

MONMOUTH 

CAMDEN 

GLOUCESTER

SALEM 

ATLANTIC 

CAPE MAY 

NEW YORK 

ATLANTIC OCEAN DELA W ARE BA Y 

RARITAN 

BAY 

Cohans e y R i v e r 

De al ware R vi er 

R a r itan Riv e r 

Navesink River 

Ma n a s q u a n R i v e r 

To m s R i v e r 

aB st ot R vi er 

M u l li c a R i v e r 

Maur ci e i R ev r 

er G ggEt a

a H br uo Rr vi er 

BURLINGTON 

OCEAN

OBSERVATION WELL AND WELL NUMBER--Figurenumber in this report for measured and simulatedhydrograph is shown in parentheses

EXPLANATION 

MARYLAND

DELAWARE 

75

39 

40 

7

7

39 

Barnegat Light 

CUMBERLAND 

11-96(29) 

33-251(45)

33-187(47) 

15-712(48)15-713(44)15-728(41) 

7-283(46) 

5-258(39)5-259(38)5-261(43)5-262(49) 

7-477(40)7-478(32) 

5-676(27) 

29-138(35)29-139(29)29-140(34)29-141(23) 

25-636(30)25-637(33)25-638(37)25-639(42) 25-353(31)

25-429(36)

25-486(9) 

1-578(24)

1-834(26)

1-37(25) 

11-96(28) 

4 

Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

Base from U.S. Department of AgricultureSoil Conservation Service, 1:250,000, 1980 

74 

Figure 22. Location of selected observation wells for which hydrographs of simulated and measured water levels have been plotted, New Jersey Coastal Plain. 
Model Calibration 33 

100 

125 

150 

175

9 

Measured 

Simulated

WATER LEVEL, IN FEET ABOVE NGVD OF 192

1978 1982 1986 1990 1994 1998


YEAR


Figure 23. Simulated and mesured water levels for well 29-141 screened in the Kirkwood-Cohansey aquifer 

system, New Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated

WATER LEVE, IN FEET BELOW NGVD OF 1929

1978 1982 1986 1990 1994 1998


YEAR


Figure 24. Simulated and measured water levels for well 1-578 screened in the confined Kirkwood aquifer, 

New Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 
34 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-100 

-75 

-50 

-25 

Measured 

Simulated

WATER LEVEL, IN FEET BELOW NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 25. Simulated and measured water levels for well 1-37 screened in the confined Kirkwood aquifer, New 

Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-50 

-25 

0 

25 

Simulated 

Measured

WATERLEVEL, IN FEET BELOW NGVD OF 1929

1988 1990 1992 1994 1996 1998


YEAR


Figure 26. Simulated and measured water levels for well 1-834 screened in the Piney Point aquifer, New Jersey Coastal Plain, 1988-98. 

(Well location shown in fig. 22) 
Model Calibration 35 

75 

100 

125 

150 

Measured 

Simulated

WATER LEVEL,

IN FEET ABOVE NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 27. Simulated and measured wter levels for well 5-676 screened in the Piney Point aquifer, New 

Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-50 

-25 

0 

25 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE OR BELOW NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 28. Simulated and measured water levels for well 11-96 screened in the Piney Point aquifer, New 

Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
36 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

75 

100 

125 

150 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE NGVD OF 1929

1978 1982 1986 1990 1994 1998


YEAR


Figure 29. Simulated and measured water levels for well 29-139 screened in the Vincentown aquifer, New 

Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 

25 

50 

75 

100 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE NGVD 0F 1929

1986 1988 1990 1992 1994 1996 1998


YEAR


Figure 30. Simulated and measured water levels for well 25-636 screened in the Vincentown aquifer, 

New Jersey Coastal Plain, 1987-98. (Well location shown in fig. 22) 
Model Calibration 37 

25 

WATER LEVEL,

IN FEET ABOVE OR BELOW SEA LEVEL 

0 

-25 

1984 1986 1988 1990 1992 1994 1996 1998 

Measured 

Simulated 

YEAR 

Figure 31. Simulated and measured water levels for well 25-353 screened in the Wenonah-Mount Laurel aquifer, 

New Jersey Coastal Plain, 1984-97. 
38 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-25 

0 

25 

50 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE OR BELOW NGVD OF 1929

1973 1976 1979 1982 1985 1988 1991 1994 1997


YEAR


Figure 32. Simulated and measured water levels for well 7-478 screened in the Wenonah-Mount Laurel aquifer, New 

Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-50 

-25 

0 

25 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE OR BELOW NGVD OF 1929

1986 1990 1994 1998


YEAR


Figure 33. Simulated and measured water levels for well 25-637 screened in the Wenonah-Mount Laurel aquifer, New 

Jersey Coastal Plain, 1987-98. (Well location shown in fig. 22) 
Model Calibration 39 

75 

100 

125 

150

9 

Measured 

Simulated

WATER LEVEL, IN FEET ABOVE NGVD OF 192

1978 1982 1986 1990 1994 1998


YEAR


Figure 34. Simulated and measured water levels for well 29-140 screened in the Wenonah-Mount Laurel aquifer, 

New Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 

25 

50 

75 

100 

Measured 

Simulated

WATER LEVEL, IN FEET ABOVE NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 35. Simulated and measured water levels for well 29-138 screened in the Englishtown aquifer system, New 

Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
40 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-175 

-150 

-125 

-100 

-75 

-50 

-25 

9 

0

Measured 

Simulated

WATER LEVEL, IN FEET BELOW NGVD OF 192

1978 1982 1986 1990 1994 1998


YEAR


Figure 36. Simulated and measured water levels for well 25-429 screened in the Englishtown aquifer system, 

New Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

25 

50 

Measured 

Simulated 

WATER LEVEL,

IN FEET ABOVE OR BELOW NGVD OF 1929

1986 1988 1990 1992 1994 1996 1998


YEAR


Figure 37. Simulated and measured water levels for well 25-638 screened in the Englishtown aquifer system, New 

Jersey Coastal Plain, 1987-98. (Well location shown in fig. 22) 
Model Calibration 41 

0 

25 

50 

75 

Measured 

Simulated

WATER LEVEL, IN FEET ABOVE NGVD 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 38. Simulated and measured water levels for well 5-259 screened in the Englishtown aqifer system, 

New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 39. Simulated and measured water levels for well 5-258 screened in the Upper Potomac-RaritanMagothy aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
42 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-100 

-75 

-50 

-25 

1973 1977 1981 1985 1989 1993 1997 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

YEAR


Figure 40. Simulated and measured water levels for well 7-477 screened in the Upper Potomac-RaritanMagothy aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-50 

-25 

0 

25 

Measured 

Simulated

WATER LEVEL, IN FEET BELOW NGVD OF 1929

1987 1989 1991 1993 1995 1997


YEAR


Figure 41. Simulated and measured water levels for well 15-728 screened in the Upper Potomac-RaritanMagothy aquifer, New Jersey Coastal Plain, 1987-98. (Well location shown in fig. 22) 
Model Calibration 43 

-50 

-25 

0 

25 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

1986 1988 1990 1992 1994 1996 1998


YEAR


Figure 42. Simulated and measured water levels for well 25-639 screened in the Upper Potomac-Raritan-Magothy 

aquifer, New Jersey Coastal Plain, 1987-98. (Well location show in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 43. Simulated and measured water levels for well 5-261 screened in the Middle Potomac-Raritan-Magothy 

aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
44 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-50 

-25 

0 

25 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

Figure 44. 

1987 1989 1991 1993 1995 1997


YEAR


Simulated and measured water levels for well 15-713 screened in the Middle Potomac-RaritanMagothy aquifer, New Jersey Coastal Plain, 1987-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL.

IN FEET BELOW NGVD 1929

Figure 45. 

1978 1982 1986 1990 1994 1998


YEAR


Simulated and measured wter levels for well 33-251 screened in the Middle Potomac-RaritanMagothy aquifer, New Jersey Coastal Plain, 1978-98. (Well location shown in fig. 22) 
Model Calibration 45 

-125 

-100 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD 0F 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 46. Simulated and measured water levels for well 7-283 screened in the Lower PotomacRaritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929 

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 47. Simulated and measured water levels for well 33-187 screened in the Lower PotomacRaritan-Magothy aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
46 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

-50 

-25 

0 

25 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

1987 1989 1991 1993 1995 1997


YEAR


Figure 48. Simulated and measured water levels for well 15-712 screened in the Lower Potomac-Raritan-Magothy 

aquifer, New Jersey Coastal Pain, 1987-98. (Well location shown in fig. 22) 

-75 

-50 

-25 

0 

Measured 

Simulated 

WATER LEVEL,

IN FEET BELOW NGVD OF 1929

1973 1977 1981 1985 1989 1993 1997


YEAR


Figure 49. Simulated and measured water levels for well 5-262 screened in the Lower Potomac-Raritan-Magothy 

aquifer, New Jersey Coastal Plain, 1973-98. (Well location shown in fig. 22) 
Model Calibration 47 

Table 4. Simulated and estimated base flows at five continuous-record streamflow-gaging stations in the New Jersey 

Coastal Plain 

U.S. Geological Survey 

Streamflow-gaging station 

Number Name Reference 

Basin 

drainage 

area, 

(square 

miles) 

Period of 

record for 

calculated 

mean base 

flow 

Calculated 

mean base 

flow, 

(cubic feet per 

second) 

Simulated 

base flow, 

(cubic feet 

per second) 

Difference, 

in percent 

01408500 Toms River Watt and 123 1928-96 184.29 164.06 11 

near Toms others, 1994, 

River, N.J. plate 3 

01467000 North Branch Watt and 118 1921-96 140.9 144.87 3 

Rancocas Creek others, 2003, 

at Pemberton, plate 3 

N.J. 

01465850 South Branch Modica, 64.5 1962-76 69.33 80.77 14 

Rancocas Creek 1996, table 3 

at Vincentown, 

N.J. 

01477120 Raccoon Creek Johnson and 26.9 1966-92 30 20.85 31 

near Swedes- Charles, 

boro, N.J. 1997, plate 3 

01482500 Salem River Johnson and 14.6 1940-90 12 16.37 27 

near Wood- Charles, 

stown, N.J. 1997, plate 3 
48 Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain 

Summary 

As part of an ongoing program to maintain ground-waterflow models constructed in New Jersey, the U.S. Geological 

Survey (USGS), in cooperation with New Jersey Department of 

Environmental Protection (NJDEP), developed a standardized 

procedure to archive the models and revise selected models by 

incorporating recent data, such as withdrawal data and simulation techniques. The Regional Aquifer System Analysis finitedifference numerical model of flow in the New Jersey Coastal 

Plain sediments (Martin, 1998) was revised by (1) rediscretizing the model parameters with a finer cell size, (2) using a spatially variable recharge rate that is based on rates determined in 

studies conducted since the model was initially developed in 

1981, and (3) using recent ground-water withdrawal data for 

1982-98. 

The revised New Jersey Coastal Plain model can be used 

as a tool to evaluate the regional effect on water levels of 

changes in ground-water withdrawals. The model can aid in reevaluating water-management strategies in the New Jersey 

Coastal Plain. 

The revised model was calibrated by trail-and-error adjustment of the storage coefficient, vertical leakance, streambed 

conductance, lateral-boundary fluxes, and recharge rates. 

Recharge rates were adjusted in areas where no previous studies 

had been done to estimate the spatial variation of recharge rates. 

These five parameters were adjusted during model calibration 

in order to minimize the difference between simulated and measured values of one or more of the following: (1) estimated base 

flow in five river basins, (2) water levels in 28 observation wells 

for which long-term hydrographs were available, and (3) potentiometric surfaces for 1978, 1983, 1988, 1993, and 1998 

ground-water-flow conditions. 

Water levels in the regional cone of depression centered 

near the Monmouth and Ocean County boundary in the 

Wenonah-Mount Laurel aquifer and Englishtown aquifer system have risen about 100 ft from 1988 to 1998. The rise in water 

levels in this area is due to a decrease in ground-water withdrawals. Model calibration revealed that storage coefficient is 

an important parameter in the recovery of water levels in this 

area. It appears that a large portion of the ground water flowing 

into this area is going into aquifer storage. Water levels in 

observation wells screened within the regional cone of depression centered near the Monmouth and Ocean County boundary 

in the Wenonah-Mount Laurel aquifer and Englishtown aquifer 

system have been increasing since 1989; therefore, water levels 

have not reached steady-state conditions with current (1998) 

ground-water withdrawals. 

References Cited 

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the region of Greenwich Township, Gloucester County, New 

Jersey: U.S. Geological Survey Water-Resources Investigations Report 90-4198, 77 p. 

Charles, E.G., Storck, D.A., and Clawges, R.M., 2001 Hydrology of the unconfined aquifer system, Maurice River area: 

Maurice and Cohansey River basins, New Jersey, 1994-95: 

U.S. Geological Survey Water-Resources Investigations 

Report 01-4229, 5 sheets. 

Harbaugh, A.W., and McDonald, M.G., 1996, User's documentation for MODFLOW-96, an update to the U.S. Geological 

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U.S. Geological Survey Open-File Report 96-485, 56 p. 

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unconfined aquifer system, Salem River area: Salem River 

and Raccoon, Oldmans, Alloway, and Stow Creek Basins, 

New Jersey, 1993-94: U.S. Geological Survey WaterResources Investigations Report 96-5195, 5 sheets. 

Johnson, M.L., and Watt, M.K., 1996, Hydrogeology of the 

unconfined aquifer system, Mullica River Basin, New Jersey, 

1991-92: U.S. Geological Survey Water-Resources Investigations Report 94-4234, 6 sheets. 

Lacombe, P.J., and Rosman, Robert, 1995, Hydrology of the 

unconfined aquifer system in the upper Maurice River basin 

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87: U.S. Geological Survey Water-Resources Investigations 

Report 92-4128, 5 sheets. 

Lacombe, P.J., and Rosman, Robert, 2001, Water levels in, 

extent of freshwater in, and water withdrawals from ten confined aquifers, New Jersey and Delaware Coastal Plain, 

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model modified to reduce computer-memory requirements 

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Report 82-4023, 59 p. 

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Plain aquifer system: U.S. Geological Survey Professional 

Paper 1404-K, 81 p. 

Lewis, J.C., Hochreiter, J.J., Barton, G.J., and Kozinski, Jane, 

1991, Hydrogeology of, and ground-water quality in, the 

Potomac-Raritan-Magothy aquifer system in the Logan 

Township region, Gloucester and Salem Counties, New Jersey: U.S. Geological Survey Water-Resources Investigations 

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Coastal Plain: U.S. Geological Survey Professional Paper 

1404-H, 146 p. 
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Meisler, Harold, 1980, Preliminary delineation of salty ground 

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U.S. Geological Survey Open-File Report 81-71, 37 p. 

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River, Metedconk River, and Kettle Creek Basins, New Jersey: U.S. Geological Survey Water-Resources Investigations 

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the Englishtown Formation, New Jersey: U.S. Geological 

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Sloto, R.A., and Crouse, M.Y., 1996, HYSEP: A computer program for streamflow-hydrograph separation and analysis: 

U.S. Geological Survey Water-Resources Investigations 

Report 96-4040, 46 p. 

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County, New Jersey: U.S. Geological Survey Water-Supply 

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for simulation of three-dimensional ground-water flow: U.S. 

Geological Survey Open-File Report 75-438, 103 p. 

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56 p. 

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unconfined aquifer system of the Great Egg Harbor River 

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Watt, M.K., Kane, A.C., Charles, E.G., and Storck, D.A., 2003, 

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Paper 1404-B, 49 p., 24 pl. 
Voronin, Lois M.—Documentation of Revisions to the Regional Aquifer System Analysis Model of the New Jersey Coastal Plain— 

U.S. Geological Survey Water-Resources Investigations 03-4268 

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