A Hydrologic Primer for 

New Jersey Watershed Management

Water-Resources Investigations Report 00-4140

Prepared in cooperation with

NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION

U.S. Department of the Interior

U.S. Geological Survey
A. Crop irrigation in central New Jersey.

B. Row crops in central New Jersey.

C. Sampling ground water from a domestic well. (Photograph by Rick Clawges)

D. Tide-telemetry (left) and weather-monitoring equipment at Cape May Harbor at U.S. 

Coast Guard Training Center, Cape May, New Jersey. (Photograph by John Stepnowski, 

National Ocean Service)

E. Development along the New Jersey coast, Seaside Heights. (File photograph U.S. 

Geological Survey, West Trenton, New Jersey)

F. Red Valley Lake, Monmouth County, New Jersey.

G. Lamington River near Pottersville, New Jersey. (Photograph by Jonathan Kennen)

H. Collecting macroinvertebrates in the Rockaway River at Boonton, New Jersey.

(Photograph by Mark Ayers)

I. Passaic River at Little Falls, showing the aqueduct that carries water from the Passaic 

River to the Wanaque Reservoir. (Photograph by Timothy Reed)

J. Industrial emmissions into the atmosphere along the lower Delaware River, New Jersey.

(File photograph, U.S. Geological Survey, West Trenton, New Jersey)

Cover layout and design: William Ellis, Jr.

Text formatting: Ingrid Heerwagen

A

B

C

D

E

F

G

H

I

J
A Hydrologic Primer for New Jersey Watershed 

Management

By Martha K. Watt

U.S. GEOLOGICAL SURVEY

Water-Resources Investigation Report 00-4140

Prepared in cooperation with the New Jersey Department of 

Environmental Protection

West Trenton, New Jersey

2000
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

ABOUT THIS REPORT--This hydrologic primer is designed to provide an introduction to basic hydrologic concepts 

and a “snapshot” of selected data-collection efforts used to assess the quality and quantity of water resources in New 

Jersey, and is not an exhaustive compilation of all data-collection programs that are underway in the State. Additional 

data collected by the N.J. Department of Environmental Protection, other Federal, State, and local governments 

agencies, and private organizations that are not presented in this report may be available. Additionally, because the 

Watershed Management Program is a dynamic program that is continually evolving, the number and locations of 

data-collection sites and the locations of watershed-management-area boundaries presented in this report may not 

reflect those in the current program.

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, Suite 206 Box 25286

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

CONTENTS

Why read this report? 1

What is a watershed? 2

Introduction 3

Acknowledgments 4

General hydrologic concepts 10

Basic definitions 10

The hydrologic cycle 12

Water budget 13

Surface-water system 14

Ground-water system 23

Water quality 25

Water-quality standards 26

Water use 28

Description of the study area 34

Geology and hydrology 34

Land use 41

Population 46

Water-resource data 48

Surface-water data 48

Streams 48

Flow-duration curves 63

Base flow 65

Flood-prone areas and wetlands 66

Lakes and reservoirs 68

Ground-water data 71

Ground-water levels 71

Major withdrawal wells 77

Water-quality data 80

Surface-water quality 81

Biological data 86

Ground-water quality 88

Saltwater monitoring 94

Potential contaminant sources 96

New Jersey Pollutant Discharge Elimination System (NJPDES) sites 96

Landfills and hazardous-waste sites 98

Atmospheric data 99

Weather stations 99

Air-monitoring points 100

How to get involved 101

List of contacts 102

Suggested reading 103

Selected references 104
iv

ILLUSTRATIONS

Figure 1-2. Maps showing the:

1. Location of N.J. Department of Environmental Protection water regions and 

watershed management areas in New Jersey 3

2. Location of N.J. Department of Environmental Protection watershed management areas and wetlands in the: 

2a. Northeast water region 5

2b. Northwest water region 6

 2c. Raritan water region 7

2d. Lower Delaware water region 8

 2e. Atlantic Coastal water region 9

3. Schematic diagram of the hydrologic cycle 12

4. Schematic diagrams showing gaining and losing streams 14

5. Map showing New Jersey watersheds that extend beyond the State boundary 16

6. Map showing location of selected reservoirs and the Delaware and Raritan Canal 17

7. Hydrograph of the discharge of two rivers in New Jersey during Hurricane Floyd, 

September 16-17, 1999 22

8. Schematic diagram showing types of openings in rocks and sediments that are capable of 

holding water 23

9. Diagram showing flow paths of ground water as it moves from recharge areas to discharge 

areas 24

10. Diagram showing example of N.J. Department of Environmental Protection water-quality 

standards, classifications, and criteria 27

11-12. Pie chart of:

11. Water used in New Jersey in 1994, by use category 31

12. Ground-water and surface-water withdrawals in the five water regions of New 

Jersey 32

13. Map showing New Jersey spans parts of four physiographic provinces 34

14. Schematic diagrams of ground-water flow systems in four representative hydrogeologic 

terrains in New Jersey 39

15. Map showing land use in New Jersey, 1991-93 43

16. Graphs showing (a) population density in New Jersey from 1880 to 1990 and 

(b) population densities of the five water regions in New Jersey in 1990, and projected 

densities for 2010 and 2040 47

17-19. Maps showing the:

17. Streamflow-gaging stations active in New Jersey in water year 1997 49

18. Low-flow partial-record stations, crest-stage partial-record stations, and 

tide-gaging stations active in New Jersey in water year 1997 51

19. Tide-telemetry stations, flood-warning systems, and weather stations active in 

New Jersey in 1999 52

20. Graph showing the relation of daily mean discharge at the Toms River near Toms River, 

N.J., streamflow-gaging station to monthly precipitation at the Toms River, N.J., weather 

station 62

21. Plot showing flow-duration curves for four stream sites in different physiographic 

provinces in New Jersey 64
v

ILLUSTRATIONS--Continued

Figure 22. Schematic diagrams showing ground-water flow associated with wetlands 67

23. Graph showing the cumulative capacity of selected large reservoirs and lakes and 

population of New Jersey from 1890 to 1990 70

24. Map showing U.S. Geological Survey ground-water monitoring wells active in New Jersey 

in 1997 71

25. Hydrographs of water levels measured in observation wells in the Coastal Plain of New 

Jersey, 1988-98 72

26-28. Maps showing the:

26. Location of Water-Supply Critical Areas in New Jersey 76

27. Location and amount of water withdrawn for public supply from the major 

aquifers in the Coastal Plain of New Jersey in 1997 78

28. Location and amount of water withdrawn for public supply from aquifers in 

northern New Jersey in 1997 79

29. Graphs showing concentrations of two nutrients, nitrate and phosphate, in streamflow 

during a typical storm 82

30-33. Maps showing the:

30. Surface-water-quality sampling sites and estuarine and tidal river monitoring 

sites active in New Jersey in 1998 85

31. N.J. Department of Environmental Protection Ambient Biomonitoring Network 

sites in New Jersey during 1992-96 87

32. Ground-water-quality and saltwater-monitoring sites in New Jersey 92

33. Nitrate concentrations in water from wells in New Jersey 93

34. Graph showing annual withdrawals from the Kirkwood-Cohansey aquifer system and late 

summer chloride concentrations in water from selected wells at (a) Point Pleasant Beach 

and (b) Seaside Heights, N.J., 1918-95 95

35-36. Maps showing the:

35. New Jersey Pollutant Discharge Elimination System surface-water-discharge 

sites in New Jersey 97

36. Weather stations and the air-monitoring station in New Jersey 99

TABLES

Table 1. Information on selected reservoirs and large lakes in New Jersey 18

2. U.S. Environmental Protection Agency and New Jersey State primary and secondary drinkingwater standards as of November 1996 29

3. Characteristics of aquifers and wells in New Jersey 40

4. Selected information for continous streamflow-gaging stations in New Jersey through water 

year 1997 54

5. Characteristics of surface-water bodies 69

6. Contaminants commonly detected in drinking water derived from ground-water sources 89
vi

BOXES

Box A. Streamflow-gaging station and hydrograph 20

B. Soils and their relation to the hydrologic system 36

C. Cartographic tools used in hydrologic studies 44

D. Constructing a water-table or potentiometric-surface map 74

E. Dissolved oxygen 84
1

A HYDROLOGIC PRIMER FOR

NEW JERSEY WATERSHED MANAGEMENT

By Martha K. Watt

To learn basic concepts about watersheds,

To learn what information (data) is collected in your watershed and 

other watersheds in New Jersey,

To learn why the data are collected and what they are used for, and 

To provide information needed to get involved and make a difference

in the management and health of your watershed.

Lamington River near Pottersville, New Jersey.

(Photograph by Jonathan Kennen)

WHY READ THIS REPORT?

•

•

•

•
2

A watershed is an area of land that drains all the streams and rainfall

to a common outlet such as the outflow of a reservoir, mouth of a bay, or 

any point along a stream channel (McCann, 1992). The word watershed is

sometimes used interchangeably with drainage basin or catchment. Ridges 

and hills that separate two watersheds are called the drainage divide. The 

watershed consists of surface water--lakes, streams, reservoirs, and wetlands--and all the underlying ground water (McCann, 1992).

Cranberry harvesting in the New Jersey Pinelands. 

(Courtesy of the Pinelands Commission)

WHAT IS A WATERSHED?
3

The U.S. Geological Survey (USGS) and the

N.J. Department of Environmental Protection 

(NJDEP), and many other agencies and organizations are striving to educate the public about New 

Jersey’s water resources. In 1996, the NJDEP began 

implementing a “watershed management approach”

to maintain the physical, chemical, and biological 

integrity of New Jersey’s waters. This approach concentrates on managing individual watershed areas by

(1) defining the physical geographic boundaries of

the watersheds, (2) basing water policy on sound scientific principles, and (3) developing partnerships 

with the public--the people most affected by watershed-management policies.

New Jersey can be divided into five water

regions as defined by the NJDEP: the Northeast, 

Raritan, Northwest, Lower Delaware, and Atlantic

Coastal water regions (fig. 1). Each water region has

been divided into three to five “watershed-management areas,” each of which encompasses a particular

group of major rivers (fig. 2a-e). Each watershedmanagement area consists of many smaller watersheds.

Northeast Region

Lower Delaware Region

Raritan Region

Northwest Region

Atlantic Coastal Region

WATER REGION

Watershed Management Area boundary and number--

From N.J. Department of

Environmental Protection,

1:24,000 digital line graph

file, 1997

Figure 1. Location of N.J. Department of 

Environmental Protection water regions and 

watershed management areas in New Jersey. 

Each water region contains three to five watershed

management areas. Each of these areas 

encompasses a particular group of major rivers 

and consists of many smaller watersheds.

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

In 1996, the N.J. Department of Environmental 

Protection began implementing a “watershed

management approach” to maintain the

physical, chemical, and biological integrity

of New Jersey’s waters.

INTRODUCTION
4

Hydrologic data collected by Federal and State 

government agencies are invaluable as resources to

policymakers who make decisions that affect the use

of water in a particular watershed. The purpose of

this report is to educate water-resource managers, 

policymakers, government officials, and the public 

about hydrologic concepts and the water-resource

data needed to make informed decisions about

water-management issues. (“Hydrologic” means 

relating to the occurrence, distribution, movement, 

and chemistry of all waters of the Earth (Fetter,

1980)). The first part of the report describes basic 

hydrologic concepts and includes explanations of the 

hydrologic cycle, the water budget, the surfacewater and ground-water flow systems, water-quality 

concepts and standards, and water use. The second

part of the report summarizes the types of waterresource data that are available from Federal and 

State government agencies. Instructions on how to

obtain the data and contact the appropriate Federal

and State agencies, as well as suggestions for additional reading, also are included.

Hydrologic data collected by

Federal and State government 

agencies are invaluable as

resources to policymakers who 

make decisions that affect the 

use of water in a particular

watershed.

The author gratefully acknowledges the many specialists and

colleagues who provided guidance, assistance, and expertise for this

report. My thanks extend to those who reviewed this document for 

technical accuracy and appropriate information: Lance Miller, Kyra

Hoffman, James Mumman, Karen Schaffer, Robert Canace, Michael 

P. Bleicher, Dave McPartland, and Fran Varacalli of the NJDEP; Eric

Evenson, David Stedfast, Robert Schopp, Jacob Gibs, Dale

Simmons, Jessica Hopple, and Marion Fisher of the USGS. 

Technical assistance was provided by my colleagues at the USGS--

William Ellis, Robert Nicholson, Kathryn Hunchak-Kariouk, 

Michael Deluca, Jonathan Marlow, John Nawyn, Donald Rice, and 

Eric Vowinkel--and by Richard Albers of the Delaware River Basin

Commission.

ACKNOWLEDGMENTS
5

0 5 10 MILES

0 5 10 KILOMETERS

STATEN ISLAND

NEW YORK

Union

County

Morris

County

Essex

County

Passaic

County

Sussex

County

Somerset

County

Hudson

County

Bergen

County

Passaic River

Whippany River

Rockaway River

Pequannock River

Ramapo River

Wanaque River

oP

mp ot n River

Passaic River

Hudson River

Hackens ack R vi e

S

r

add el R vi er

NEW YORK

NEW JERSEY

15'

41

40

45'

74 30'

41

15'

74 00'

Pompton, Pequannock, Wanaque, and Ramapo Rivers

Lower Passaic River and Saddle River

Hackensack and Hudson Rivers, and Pascack Brook

Upper Passaic, Whippany, and Rockaway Rivers 

Watershed Management Area boundary--From N.J.

Department of Environmental Protection, 1:24,000 

digital line graph file, 1997

WATERSHED MANAGEMENT AREA

Wetlands--From Landsat thematic mapper

data, 1991-93

3

EXPLANATION

5

4

4

5

3

6

6

Figure 2a. Location of N.J. Department of Environmental Protection watershed management 

areas and wetlands in the Northeast water region.

Base from U.S. Geological Survey

digital line graph files, 1:24,000
6

0 5 10 MILES

0 5 10 KILOMETERS

Hunterdon

County

Somerset

County

Union

County

Middlesex

County

Morris

County

Essex

County

Monmouth

County

Passaic

Susse County x

County

Warren

County

Mercer

County

Figure 2b. Location of N.J. Department of Environmental Protection watershed management area and 

wetlands in the Northwest water region.

75 74 30'

41

40

45'

39

15'

75 15'

41

15'

74 45'

40

30'

PENNSYLVANIA

NEW JERSEY

NEW YORK

Papakating Creek

Wallkill River

Flat Brook

Paulins Kill

Yards Creek

Pequest River

Delaware River

Lopatcong Creek

Pohatcong

Creek

Musconetcong River

Delaware an d Raritan

Canal

e D al wa er R vi er

1

2

11

Base from U.S. Geological Survey

digital line graph files, 1:24,000

Upper Delaware River

Wallkill River, Pochuck and

Papakating Creeks

Central Delaware tributaries

Watershed Management 

Area boundary--From N.J.

Department of Environmental 

Protection, 1:24,000 digital 

line graph file, 1997

WATERSHED MANAGEMENT AREA

Wetlands--From Landsat thematic

mapper data, 1991-93

1

EXPLANATION

11

2
7

0 5 10 MILES

0 5 10 KILOMETERS

WARREN

COUNTY

MORRIS

COUNTY

PASSAIC

COUNTY BERGEN

COUNTY

ESSEX

COUNTY

HUDSON

COUNTY

UNION

COUNTY

STATEN ISLAND

NEW YORK

MONMOUTH

COUNTY

MIDDLESEX

COUNTY

MERCER

COUNTY

HUNTERDON

COUNTY

SOMERSET

COUNTY

PENNSYLVANIA

NEW JERSEY

75 00' 30' 74 15'

40 

45'

30'

40 

15'

74 45'

Figure 2c. Location of N.J. Department of Environmental Protection watershed management area and wetlands 

in the Raritan water region.

Elizabeth, Rahway, and Woodbridge Rivers

North and South Branch Raritan Rivers

Lower Raritan River, South River, and Lawrence Brook

Millstone River

Watershed Management Area boundary--From N.J.

Department of Environmental Protection, 1:24,000 

digital line graph file, 1997

WATERSHED MANAGEMENT AREA

Wetlands--From Landsat thematic mapper

data, 1991-93

Base from U.S. Geological Survey

digital line graph files, 1:24,000

10

EXPLANATION

8

10

7

9

7

8

9

Elizabeth River

Rahway River

Raritan River

Lawrence Brook

South

R i ver

Manalapan Brook

Millstone River

Delaware an d

Raritan Canal

Delaware River

South Branch Raritan River

Round Valley 

Reservoir

Spruce Run

Reservoir

South Branch

Raritan River

Lam ni gton R vi er

North Br anch

Raritan

R vi er

Raritan Bay
8

0 10 20 MILES

0 10 20 KILOMETERS

NEW JERSEY

ATLANTIC OCEAN

Maurice

River

MERCER

COUNTY MONMOUTH

COUNTY

OCEAN

COUNTY

BURLINGTON

COUNTY

CAMDEN

COUNTY

GLOUCESTER

COUNTY

ATLANTIC

COUNTY

SALEM

COUNTY

CUMBERLAND

COUNTY

CAPE MAY

COUNTY

75 30' 15' 75 00' 45' 74 30'

40 

00'

39 

45'

30'

39 

15'

PENNSYLVANIA

DELAWARE

Alloway Creek

Cohansey River

Sa

el m

River

Oldmans Creek

R accoon Creek

Big Timber Creek

Cooper River Pennsauken Creek

Rancocas Cree

Dela

k

ware River

Crosswicks Creek

Figure 2d. Location of N.J. Department of Environmental Protection watershed management area and wetlands 

in the Lower Delaware water region.

18

17

20

19

Maurice and Cohansey Rivers

Salem River and Lower Delaware tributaries

Rancocas Creek

Crosswicks Creek

Watershed Management 

Area boundary--From N.J.

Department of Environmental 

Protection, 1:24,000 digital 

line graph file, 1997

WATERSHED MANAGEMENT AREA

Wetlands--From Landsat thematic mapper 

data, 1991-93

Base from U.S. Geological Survey

digital line graph files, 1:24,000

17

18

19

20

EXPLANATION
9

0 10 20 MILES

0 10 20 KILOMETERS

HUNTERDON

COUNTY

SOMERSET

COUNTY

MIDDLESEX

COUNTY

MERCER

COUNTY

BURLINGTON

COUNTY

CAMDEN

COUNTY

GLOUCESTER

COUNTY

CUMBERLAND

COUNTY

CAPE MAY

COUNTY

ATLANTIC

COUNTY

OCEAN

COUNTY

MONMOUTH

COUNTY

PENNSYLVANIA

NEW JERSEY

ATLANTIC OCEAN

Delaware River

Base from U.S. Geological Survey

digital line graph files, 1:24,000

14

15

12

13

16 Monmouth watersheds

Barnegat Bay watersheds

Mullica and Wading Rivers

Great Egg Harbor and Tuckahoe Rivers

Cape May watersheds

Watershed Management Area boundary--From N.J. 

Department of Environmental Protection, 1:24,000 

digital line graph file, 1997

WATERSHED MANAGEMENT AREA

Wetlands--From Landsat thematic

mapper data, 1991-93

12

13

14

15

16

EXPLANATION

Tuckahoe River

Great Egg Harbor River

Mullica River

Wading River

Forked River

Ced ar Creek

Toms River

Metedeconk River

Manasquan River

Navesink River

75 00’ 45’ 30’ 15’ 74 00’

40 

30’

15’

45’

39 

00’

40

30’

15’

Figure 2e. Location of N.J. Department of Environmental Protection watershed 

management area and wetlands in the Atlantic Coastal water region.
10

Basic definitions

Key terms used in this report include--

ATMOSPHERIC DEPOSITION--The process by which dust and 

chemicals in the atmosphere are deposited on a surface through precipitation, such as rain or snow, or through settling or adsorption 

(Lear, 1997).

AQUIFER--Layer(s) of either unconsolidated sediments or consolidated rock with interconnected voids, such as fractures, that will

yield water in a usable quantity to a well or spring.

BASE FLOW--Sustained or fair-weather streamflow. In most 

streams, base flow is composed largely of ground-water discharge 

(Langbein and Iseri, 1960).

CARBONATE ROCK--A rock that consists primarily of limestone

or dolomite. Carbonate rock can be highly permeable. (See “permeability,” below.)

CONFINED AQUIFER--An aquifer that is bounded above and 

below by sediments or rocks of lower permeability (confining unit).

CONFINING UNIT--Layer(s) of rock or unconsolidated sediments 

with low permeability relative to immediately adjacent rock or sediment layers.

DRAWDOWN--The lowering of the water table in an unconfined 

aquifer or the potentiometric surface in a confined aquifer caused by 

pumping ground water from wells.

HYDRAULIC HEAD--The energy of a water mass, which is a function of elevation, pressure, and velocity. A measure of hydraulic

head in an aquifer is the level to which water rises in a well. Differences in hydraulic head over distance cause ground water to flow.

JOINT--A type of fracture in which displacement of the rock does 

not occur.

PERMEABILITY--A property of a layer of rock or unconsolidated

sediments that determines how easily a fluid, such as water, can 

move through it. Sands and gravels have high permeabilities; silts 

and clays have low permeabilities.

GENERAL HYDROLOGIC CONCEPTS
11

POROSITY--The ratio of the volume of open (void) spaces in a rock

or sediment through which fluid can flow to the total volume of the 

rock or sediment.

POTENTIOMETRIC SURFACE--A surface that represents the 

level to which water will rise in tightly cased wells. The water table

is the potentiometric surface of an unconfined aquifer. (See “unconfined aquifer,” below.)

RECHARGE--The addition of water to the saturated zone. Recharge 

can result from the infiltration of precipitation, from the flow of

water from a surface-water body into an aquifer, or from the injection of water through an injection well.

SATURATED ZONE--The zone in which the openings (voids) in

the rocks or soil are filled with water at pressure greater than atmospheric. The water table is the top of the saturated zone in an unconfined aquifer.

SPRING--A point where the ground-water surface intersects the 

land surface and ground water flows freely from sediments or rocks 

onto the land or into a surface-water body.

STREAMFLOW--The rate at which surface water moves through a

stream channel. Often referred to as discharge in reports by the

USGS.

UNCONFINED AQUIFER--An aquifer that is near land surface and 

is not overlain by a confining unit. Also called a water-table aquifer.

UNSATURATED ZONE--The zone between the land surface and 

the water table. The openings (voids) contain water at less than

atmospheric pressure, as well as air and other gases.

VALLEY FILL--A body of unconsolidated sediment (glacial drift or 

till) deposited within a valley by glaciers.

WATERSHED--The land area that drains all the streams and rainfall

to a common outlet, such as the outflow of a reservoir, the mouth of

a bay, or any point along a stream channel (McCann, 1992). Sometimes referred to as a drainage basin or catchment.

WATER TABLE--The upper surface of the saturated zone, below 

which the openings in the rock are completely filled with water. At

the water table, the water pressure equals atmospheric pressure.
12

The hydrologic cycle

Water is everywhere--in the atmosphere (air), 

streams, lakes, and rivers, and in the ground. We take

it for granted. We never think about the fact that all

the water in the world is connected to and caught up

in the hydrologic cycle. The hydrologic cycle refers

to the constant movement of water above, on, and

below the Earth’s surface (Heath, 1983, p. 5). 

Although the hydrologic cycle really has no beginning or end, the cycle can be said to begin as rain 

falls to the land surface and surface-water bodies, 

such as lakes, rivers, and the ocean (fig. 3). Some of

the rain that falls on the land surface soaks into the 

ground. Some of this water works its way down

through the soil to the water table--the top of the saturated zone. This process is called infiltration. Once 

it reaches the water table, the water is called ground

water. Ground water either moves through the shallow part of the ground (horizontally near the ground 

surface as interflow) and discharges to a surfacewater body--a stream, a lake, or the ocean--or continues to flow downward to other, deeper aquifers

(recharge). Once the ground is saturated, or has

absorbed all the water that it can, like a sponge, the 

remaining rain runs over the land surface and into

stream channels. This process is called overland

flow (overland runoff or direct runoff). Overland

flow also occurs when rainfall exceeds the infiltration rate--the rate at which water is absorbed by the 

sediments. The water in a stream is made up of precipitation, overland flow, and ground-water discharge. Evaporation takes place at the surface of

streams, lakes, and the ocean, and on the land surface, returning water to the atmosphere. Plants also

use the water by drawing it up through their root systems and returning it to the atmosphere (transpiration). The evaporated and transpired water

(evapotranspiration) condenses and forms clouds 

and, ultimately, rain, completing the hydrologic 

cycle.

Evaporation

Clouds forming

Precipitation

Overland runoff

Infiltration

Water table

Ground water

Freshwater - saltwater

Saltwater

Ocean

interface

Figure 3. Schematic diagram of the hydrologic cycle 

(modified from Heath, 1983). Water moves constantly 

through the hydrologic cycle. Rain runs over the land 

surface and into streams, which discharge into the 

ocean. Some rain infiltrates into the ground-water 

system and discharges to streams or the ocean. 

Transpiration and evaporation return water to the 

atmosphere, completing the cycle.

Saturated zone

Unsaturated zone

Transpiration

Hydrologic cycle refers to the constant movement 

of water above, on, and below the Earth’s surface.
13

Development encroaching on agricultural land in

southern New Jersey. (File photograph, U.S.

Geological Survey, West Trenton, New Jersey)

Water budget

Each component of the hydrologic cycle--precipitation, recharge, streamflow, evaporation, transpiration, and ground- and surface-water 

withdrawals, as well as changes in the amount of

water stored in the ground (ground-water storage)

and in reservoirs, lakes, and the ocean (surface-water

storage)--can be assigned a value in order to create a 

water budget. The water budget considers all waters, 

both surface and subsurface, entering, leaving, or

stored within the watershed, and must always balance. The water budget provides a basis for evaluating change. Perhaps citizens of a town are thinking

of rezoning an area to allow the building of condominium complexes, shopping malls, or new industries. These new facilities will require water.

Questions that would need to be considered might 

include--how much water will be needed? From 

what source, ground water or surface water? Is

enough water available? And, if so, for how long?

How will this development affect wells and streams

in the area? The estimated change in the water budget is one factor that can be considered in determining whether enough water is available to meet the 

additional demands. It is important to remember that

when a new water demand is added or an existing

demand is increased, the other components of the 

water budget must be adjusted to compensate for the

change. For example, an increase in withdrawals

from wells to supply a growing population may

reduce the amount of ground water that reaches a

stream, affecting the fish in the stream, the towns 

downstream that use the stream for water supply, and 

the quality of water in the stream. 
14

Surface-water system

One part of the hydrologic system, the surfacewater system, is made up of all the water that is

present at the Earth’ssurface, such asrivers, streams,

lakes, ponds, canals, reservoirs, and the ocean. As it

rains, water drops may fall directly on one of these

surface-water bodies, or it may fall on the land surface first and then travel over land and into the surface-water body (overland flow). Streams, lakes, and 

oceans are located at topographic low points, so all 

water flows toward them. Streams typically originate

at topographic high points. The uppermost reach of a 

stream is called its headwaters. The land area from 

which surface water drains into a stream system is

called its watershed or drainage basin. Streams in a 

watershed can be classified according to stream

“order.” A small, unbranched stream, typically a 

headwaters stream, is a first-orderstream. When two 

first-order streams join, they form a second-order 

stream. A third-order stream has tributaries that are

first- and second-order streams. Streams also can be 

classified as “gaining” or “losing.” A gaining stream 

accumulates water as it flows to lower elevations.

Water seeps into a gaining stream from its banks and 

channel bottom. A losing stream loses water as it

flows to lower elevations. Water seeps out of the 

sides and bottom of a losing stream and into its banks

(fig. 4).

Flow direction

Shallow aquifer

Water table

Unsaturated zone

GAINING STREAM

Figure 4. Gaining and losing streams (from Winters 

and others, 1998). Gaining streams receive water 

from the ground-water system. Losing streams lose 

water to the ground-water system. Note the height of 

the water table in relation to stream height. The water 

table adjacent to losing streams is lower than the 

stream level. The water table adjacent to gaining 

streams is higher than the stream level.

Flow direction

Water table Unsaturated zone

LOSING STREAM

A gaining stream accumulates water as it flows to lower

elevations. Water seeps into a gaining stream from its banks

and channel bottom. A losing stream loses water as it flows

to lower elevations. Water seeps out of the sides and bottom 

of a losing stream and into its banks.
15

Watersheds differ in size. Major watersheds

drain the largest rivers and all of their tributaries. For

example, watersheds in parts of New York, Pennsylvania, New Jersey, and Delaware, with a total area of

12,765 mi2

 (square miles) excluding the surface area

of Delaware Bay (fig. 5), drain into the Delaware

River (U. S. Geological Survey, 1986a). Smaller 

watersheds may drain only the area surrounding a 

first-order stream. Watersheds are natural features

that are unrelated to political boundaries. The headwaters and only 17 percent of the total watershed of

the Wallkill River are within New Jersey. The 

Wallkill River flows north and discharges into the

Hudson River in New York State. The Passaic and

Hackensack Rivers, in contrast, have their headwaters in NewYork State, but 84 and 69 percent of their 

watersheds, respectively, lie in New Jersey (U.S.

Geological Survey, 1986a) (fig. 5). Most of the 

streams and rivers in the Northwest water region and 

all of the streams and rivers in the Lower Delaware

water region drain into the Delaware River, which 

drains into the Atlantic Ocean. Rivers in the Atlantic

Coastal, Northeast, and Raritan water regions drain

into the Atlantic Ocean. All of these large watersheds contain hundreds of smaller subbasin areas. 

The USGS has divided all the stream systems in New

Jersey into 896 subwatersheds (Ellis and Price,

1995). The watershed designations are important for 

cataloging water data, monitoring and regulating 

water use, and planning and describing water-use 

activities. (Ellis and Price, 1995). 

Passaic River at Little Falls, New Jersey showing 

the aqueduct that carries water from the Passaic

River to the Wanaque Reservoir. (Photograph by 

Timothy Reed)
16

Delaware River

New York

Pennsylvania

New Jersey

Maryland Delaware

0 10 20 30 MILES

0 10 20 30 KILOMETERS

Passaic Ri ver

Hackensack River

Raritan River

Wallkill

River

Ramapo

River

River

Hudson

ATLANTIC

OCEAN

D e l a ware Ri ve r

Raritan

Bay

Saddle

River

75 74

41

40

39

76

42

DELAWARE BAY

PENNSYLVANIA DELAWARE

NEW YORK

MARYLAND

NEW JERSEY

Figure 5. New Jersey watersheds that extend beyond the State boundary. The Delaware

River Basin encompasses parts of New York, Pennsylvania, New Jersey, and Delaware

and covers 12,765 square miles. Only 17 percent of the Wallkill River Basin, its headwaters,

is in New Jersey. In contrast, most of the Passaic and Hackensack River Basins (84 and 69 

percent, respectively) are in New Jersey, but their headwaters are in New York.

Delaware River Basin

Wallkill River Basin

Passaic River Basin

and Hackensack River 

Basin

Basin boundary

EXPLANATION

Base from U.S. Geological Survey

digital line graph files, 1:100,000

16
17

Reservoirs are built on a stream to collect the 

flow of the stream for a variety of uses. Most reservoirs in New Jersey were built to supply the public

with drinking water and also are used for recreation. 

Reservoirs also are used to store water for release 

back into the stream during times of drought to maintain a given volume of water in the stream, usually 

for water supply for an intake downstream. Maintaining adequate flow downstream from reservoirs is

important for several reasons. The flow provides an

ecological balance for the animals living in the

stream, may dilute contaminants, or may be needed

for use in industrial cooling or power generation. 

Most reservoirs in New Jersey are in the northern

part of the State (fig. 6) and are used for drinkingwater supply. The availability of water from aquifers

in the northern part of the State is not as great as that

from aquifers in the southern part of the State. Consequently, water demands in densely populated

northern New Jersey make reservoirs a necessity. 

Reservoirs affect both the amount and quality of

streamflow. The release of reservoir water supplements streamflow during dry periods. Reservoirs and

lakes provide the added benefit of reducing the 

severity of flooding during times of high precipitation and high flow. Sediments lining the bottom of

the reservoir act as filters that trap nutrients and contaminants. The stream habitat in the area around the 

reservoir and downstream also is altered by the regulation of flows provided by the reservoir. Information on selected reservoirs and large lakes in New 

Jersey is listed in table 1.

Delaware and Ra ri at n Canal

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

1

2

3

4

32

28

23 24

31

30

29

21

25 26

34

35 36

15 16

17 27

5

6

7

8

9 11

12

13

14

18

19 20 22

37

38 33

10

Figure 6. Location of selected reservoirs and the 

Delaware and Raritan Canal. Most of the reservoirs 

are in northern New Jersey where the ground-water 

resources are insufficient to supply the large 

population as a result of the geologic characteristics 

of the rocks. This makes the reservoirs a necessity.

Watershed Management 

Area boundary--From N.J.

Department of Environmental 

Protection, 1:24,000 digital line 

graph file, 1997

Reservoir and reference number.

Reference number corresponds 

to number listed in table 1

EXPLANATION

33

The availability of water from aquifers in the northern part of 

the State is not as great as that from aquifers in the southern

part of the State. Consequently, water demands in densely 

populated northern New Jersey make reservoirs a necessity. 
1

8

Table 1. Information on selected reservoirs and large lakes in New Jersey[USGS, U.S. Geological Survey; NJDEP; New Jersey Department of Environmental Protection; NY, New York; PS, public supply; R, recreation; S, storage; H, hydroeleusable capacity;**, combined capacity of Canoe Brook reservoirs 1, 2, and 3; --, data not available; ~, about; MUA, Municipal Utilities Authority;WC, Water Company; 

Reference

number

(figure 

6)

USGS 

station

number

NJDEP

water

region Name Latitude Longitude County Name of river

Drainage 

area

(square

miles)

Total

capacity

(billion

gallons)

Date

completed Use 

1 01376700 Northeast De Forest Lake 410623 735801 Rockland, NY Hackensack River 27.5 5.7 1956 PS Unit2 01376950 Northeast Lake Tappan 410105 740005 Bergen Hackensack River 49.0 3.9 1966 S Unit3 01377450 Northeast Woodcliff Lake 410100 740300 Bergen Pascack Brook 19.4 .87 1905 S Unit4 01378480 Northeast Oradell 405700 740200 Bergen Hackensack River 113 3.5 1922 PS Unit5 01379990 Northeast Splitrock 405740 742745 Morris Beaver Brook 5.50 3.3 1948 S Jerse6 01380900 Northeast Boonton 405345 742355 Morris Rockaway River 119 7.6 1904 PS Jerse7 01382100 Northeast Canistear 410630 742930 Sussex Pacock Brook 5.6 2.4 1896 S New8 01382200 Northeast Oak Ridge 410230 743010 Passaic Pequannock River 27.3 3.9 1880 S New9 01382300 Northeast Clinton 410430 742700 Passaic Clinton Brook 10.5 3.5 1889 S New

10 01382380 Northeast Charlotteburg 410134 742530 Passaic Pequannock River 56.2 3.0 1961 PS New

11 01382400 Northeast Echo Lake 410300 742430 Passaic Macopin River 4.35 1.6 1925 S New

12 01383000 Northeast Greenwood Lake 410936 742003 Passaic Wanaque River 27.1 6.9 * 1837 R State 13 01384002 Northeast Monksville 410720 741749 Passaic Wanaque River 40.4 7.0 1988 S Wan14 01386990 Northeast Wanaque 410242 741744 Passaic Wanaque River 90.4 29.6 1927 PS Nort

Com

15 -- Northeast Canoe Brook No. 1 404451 742102 Essex Passaic River -- 3.1** 1900 PS New 16 -- Northeast Canoe Brook No. 2 404447 742142 Essex Passaic River -- -- 1938 PS New 17 -- Northeast Canoe Brook No. 3 404724 742142 Essex Passaic River -- -- 1957 PS New 18 -- Northeast Pines Lake 405930 741606 Passaic Haycock Brook 3.76 1.9 1927 R Pine19 01387860 Northeast Point View 405818 741524 Passaic Haycock Brook 1.89 2.8 1964 S Pass20 -- Northeast Kakeout 405924 742159 Morris Stonehouse Brook 5.30 .955 1926 PS Butle21 -- Northeast Clyde Potts 404822 743452 Morris Harmony Brook 2.1 .34 1932 PS Sout22 -- Northeast Haledon 405844 741145 Bergen Molly Ann Brook 1.55 .225 1926 PS Hale23 01396790 Raritan Spruce Run 403837 745526 Hunterdon Spruce Run 41.3 11.0* 1963 S, R New 24 01397050 Raritan Round Valley 403639 745042 Hunterdon Prescott Brook 5.7 55.0 1966 S, R New 25 01405000 Raritan Farrington Lake 402700 742705 Middlesex Lawrence Brook 34.4 .655 1927 S New 26 01405500 Raritan Duhernal 402424 742209 Middlesex South River 94.6 .138 1939 AR Duhe27 -- Raritan Orange 404607 741702 Essex West Branch Rahway

River

6.3 .25 1883 PS Oran

28 01455221 Northwest Merrill Creek 404342 750611 Warren Merrill Creek 3.13 16.6 1987 S Merr29 01455400 Northwest Lake Hopatcong 405500 743950 Morris Musconetcong River 25.3 7.5* 1828 R State 30 -- Northwest Lake Mohawk 410200 743842 Sussex Wallkill River 4.38 2.3 1927 R Lake 31 -- Northwest Yards Creek 405954 750148 Warren Yards Creek 3.08 1.76 1965 H GPU 32 -- Northwest Branchville 411144 744358 Sussex Dry Brook .37 .150 1911 PS Bran33 01411878 Lower Delaware Union Lake 392406 750318 Cumberland Maurice River 216 3.8 1867 R State 34 01407500 Atlantic Coastal Swimming River 401906 740706 Monmouth Swimming River 49.2 2.25 1901 PS New 35 01407965 Atlantic Coastal Manasquan 401048 741140 Monmouth Timber Swamp Brook 3.18 4.7 1990 PS New 36 -- Atlantic Coastal Glendola 401137 740523 Monmouth Robins Swamp Brook .34 1 1962 PS New 37 -- Atlantic Coastal Kuehnle 392620 743300 Atlantic Absecon Creek 8.65 .250 ~1910 S Atlan38 -- Atlantic Coastal Doughty Pond 392548 743119 Atlantic Absecon Creek 5.85 .245 ~1910 PS Atlan
19

Duhernal Lake in Middlesex County, New Jersey. 

(File photograph, U.S. Geological Survey, West 

Trenton, New Jersey)

The State’s major canal, the Delaware and

Raritan Canal (D and R Canal), was used at one time 

for navigation but now is used only for transferring

water. Water is taken from the Delaware River,

moved through the canal and diverted for public supply, and the remainder is discharged to the Raritan 

River (fig. 6). Other canals in the State are no longer 

in operation. 

The USGS maintains a network of stations in

New Jersey for measuring how much water is flowing in the streams (stream discharge) and the height 

of the water above a selected point (stream stage). 

These measurements provide data that State and

local officials can use in many ways: for flood forecasting; allocating water for municipal use, irrigation, and industries; developing and operating

recreation facilities; protecting and maintaining

Streamflow-gaging station, Stony Brook at

Princeton, New Jersey. (Photograph by Jerry 

Ludlow)

aquatic ecosystems; delineating and managing 

floodplains; designing and operating reservoirs, 

designing highway bridges and culverts; and scheduling power production (Wahl and others, 1995).The 

USGS has been gaging (measuring) streamflow in

various streams in New Jersey since 1897 (Gillespie

and Schopp, 1982). Several stations have been operating since the 1920’s or 1930’s. The longer the

period of record at a given gaging station, the more

likely it is that many different hydrologic conditions

at that station, such as floods of different magnitudes, or droughts, have been observed. Data collected at long-term stations can provide more

accurate information than stations with only a few 

years of data because seasonal and yearly variations 

can be averaged over many years. In any given year, 

the USGS collects daily discharge data at nearly 100 

established sites statewide. (See Box A).
20

 Streamflow commonly is measured at a gaging station--a structure on the banks of the stream, or 

sometimes directly in the stream. The gaging station typically is made of concrete, concrete block, 

concrete pipe, or steel pipe (diagram A-1). This structure contains a “stilling well,” a hole dug into the 

ground on the bank of the river. The well is lined so that water from the banks of the river cannot 

enter and no water can seep out. An intake pipe from the stream connects the stilling well to the 

stream, and water fills the stilling well to the height of the water in the stream. A float device lowered 

to the surface of the water in the stilling well is used to determine stream stage (the height of the water

surface above an established level). The stilling well protects the float from fluctuations caused by 

wind and turbulence. The float rises and falls with the water level in the stream. A pulley attached to 

the float is connected to a water-level recorder. The recorder typically is a battery-operated instrument 

that produces either a punched tape or an electronic record of the rise and fall of the water level in the

stream over time. (See Wahl and others, 1995.) 

 In order to determine discharge from the stage measurements made at the streamflow-gaging station,

a stage-discharge relation is developed by making periodic measurements of discharge at the same site.

Discharge is equal to the cross-sectional area of the stream multiplied by the velocity of the water.

Physical measurements of the velocity of the water and the cross-sectional area of the stream are made

by wading the stream with a current meter and wading rod or by measuring from a bridge or cableway.

The discharge measurements made over the range in stage of the stream are plotted against the stage

that was recorded at the same time to define the stage-discharge relation for the stream at that station.

The stage-discharge relation is then used in conjunction with the recorded stage to determine discharge

throughout the year (Wahl and others, 1995.)

 The relation between stage and discharge is constantly changing as a result of erosion of streambed

or banks, deposition of material to streambed or banks, growth of vegetation in the channel or on the

banks, snow, or ice. Therefore, establishing a stage-discharge relation is a continual process of

making measurements and comparing them to historical measurements to assess change over time.

 A hydrograph, or graph showing discharge in units of cubic feet per second at a single location as 

a function of time, can be used to study long- and short-term changes in the discharge of the stream. 

The hydrograph can be divided graphically into sections that represent the various components of

streamflow, such as ground-water discharge, overland flow, precipitation, and interflow (Fetter, 1980).

 A hydrograph of the discharge of the Toms River near Toms River, N.J., during 1978-97, recorded 

at a streamflow-gaging station, is shown in graph A-2. This is only a small part of the record available 

for this site, where a gaging station has been operating since October 1928. A few dozen streamflowgaging stations throughout the State have been operating since the early 1920’s (R.D. Schopp, U.S. 

Geological Survey, oral commun., 1998). Other, temporary stations that were installed for specific 

data-collection purposes may have a period of record that is as short as 1 day.

A

Streamflow-gaging station and hydrograph

20
21

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996

WATER YEAR

10

10,000

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

DISCHARGE, IN CUBIC FEET PER SECOND

Discharge at Toms River near Toms River, 

N.J., streamflow-gaging station

A-2.

Recorder

Shelf

Floor

Water surface Water surface

Valves Intakes

(From Wahl and others, 1995)

(A-1) Schematic diagram of a typical streamflow-gaging station and (A-2) hydrograph of discharge at the 

Toms River near Toms River, N.J., streamflow-gaging station, water years 1978-97. Discharge is measured 

by battery-operated recorder. The hydrograph shows only a portion of the discharge record at this station, 

which has been in operation since October 1928.

A-1.
22

The topography, land use, and geology within 

a watershed affects streamflow. Runoff in steep terrain reaches the stream faster than runoff in flatter 

terrain, where more of the water infiltrates into the 

ground. Generally, streams in watersheds that are

highly developed and have large impervious surface

areas such as parking lots, roads, houses, and shopping malls receive significant amounts of overland

flow because little water can infiltrate into the 

ground. Consequently, streams in urban watersheds

are likely to have high flow peaks immediately after 

storms. Urban areas also can have storm sewers that

drain directly to streams, allowing stormwater to

reach the stream faster. Streams in watersheds that

are more rural or undeveloped are likely to experience a more gradual rise in the water level over time,

as precipitation that has infiltrated into the ground

makes its way slowly to the water table and then

through the ground-water system to the stream.

Similarly, the hydrograph of a stream (a line

representing stream discharge or stream stage) in an

area where bedrock (consolidated rock underlying 

unconsolidated material) is near or exposed at the 

land surface area is likely to show steep, high peaks

soon after a storm, because the bedrock prevents the

rain from infiltrating into the ground. The

hydrograph of a stream in an area where the surficial

sediments are sandy is likely to show more gradual,

smaller peaks of a longer duration because water can 

infiltrate the sand easily (fig. 7). In addition, streamflow downstream from reservoirs or regulated lakes 

typically is more constant than flow in a natural,

unregulated stream. 

Seasonal differences in watershed conditions 

also can affect streamflow. During winter, frozen 

ground can prevent water from infiltrating. In spring,

if the ground is already saturated, additional rain will

flow directly to the stream as overland flow. In both

cases, a streamflow hydrograph will show larger, 

steeper peaks than are likely to be observed when the 

ground is neither frozen nor saturated.

1

10,000

2

3

4

5

7

10

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

DISCHARGE, IN CUBIC FEET PER SECOND

Discharge at Great Egg Harbor

River at Folsom, N.J., streamflow-gaging station

Discharge at Stony Brook at

Princeton, N.J., streamflowgaging station

Stony Brook

Great Egg Harbor River

Figure 7. Hydrograph of the discharge of two rivers 

in New Jersey during Hurricane Floyd, September 

16-17, 1999. Between 7.5 and 10 inches of rain fell 

on the Stony Brook watershed, causing the stream’s 

discharge to peak at about 9,000 cubic feet per 

second within hours of the heavy rainfall. The Great 

Egg Harbor River watershed received approximately 

5 inches of rain over the same period, but the peak 

discharge reached only 359 cubic feet per second, 

roughly 25 times less than the peak discharge of 

Stony Brook, and occurred about 42 hours after 

discharge peaked in the Stony Brook watershed. 

Topography, land use, and geology in the watershed 

affect the shape of the streamflow hydrograph. The 

Stony Brook watershed is more developed and has 

steeper terrain than the Great Egg Harbor River 

watershed. The geology is bedrock covered by a thin

layer of soil. Infiltration is minimal and peaks in 

streamflow represent overland flow reaching the 

stream. The storm peak occurs and recedes quickly. 

The Great Egg Harbor River watershed is less 

developed and has flatter terrain and sandy soils that

allow overland runoff to infiltrate. The river rises more

slowly and its hydrograph shows a lower and broader 

peak flow that occurs later and is of longer duration.

Period of intense rain

September 1999

12 13 14 15 16 17 18 19 20 21 22 23

Generally, streams in watersheds that are highly developed and have large impervious

surface areas such as parking lots, roads, houses, and shopping malls receive significant 

amounts of overland flow because little water can infiltrate into the ground. Consequently, 

streams in urban watersheds are likely to have high flow peaks immediately after storms. 
23

Ground-water system

The water that infiltrates through the land surface moves downward through the soil and the unsaturated zone to the water table (fig. 3). The water 

table is the top of the saturated zone, and rocks and 

sediments below the water table are saturated. This

water is called ground water. Ground water is stored

in and flows through layers of consolidated or 

unconsolidated rocks or sediments called aquifers. 

Aquifers are geologic units that can store and transmit water at rates sufficient to supply reasonable 

amounts to wells (Fetter, 1980, p. 92). Consolidated 

rock consists of mineral particles of various sizes and 

shapes that have been cemented, fused, or melted 

together by heat and pressure or chemical reaction. 

Unconsolidated rock is derived from the physical

breakdown (by erosion by running water or freezing 

and thawing) or chemical decomposition of consolidated rock, and consists of sediments such as gravel, 

sand, silt, and clay.

Two important properties of aquifers are 

porosity and permeability. Porosity is a measure of

how much water a rock can hold. If a rock is coarsegrained and well-sorted (all the grains are approximately the same size), then the space between the 

grains accounts for a large percentage of the open

space within the rock and the rock can hold a large

amount of water. Rock that has many joints and fractures or that has been dissolved by the water flowing

through it also can hold large amounts of water. If a 

rock is poorly sorted (is made up of grains of different sizes), then spaces between the larger grains are 

filled with smaller grains, resulting in less room for 

water. Generally, well-sorted rock can hold more

water than poorly sorted rock (fig. 8). Permeability is

a measure of how well-connected the pore spaces 

are. A rock with pore spaces that are not connected

cannot transmit water, or is not permeable, no matter

how great its porosity may be. Aquifers can be composed of sand and gravel, sandstone, limestone that

contains fractures, solution cavities, or caverns, or

granite that has many joints and fractures.

WELL-SORTED SAND POORLY SORTED SAND

FRACTURES IN

GRANITE

CAVERNS IN

LIMESTONE

Figure 8. Types of openings in rocks and sediments 

that are capable of holding water. Well-sorted rocks 

and sediments, rocks with many fractures, or rocks 

with large areas that have been dissolved can hold 

more water than poorly sorted, unfractured, or 

undissolved rocks (modified from Heath, 1983).

Aquifers are geologic units that can store and

transmit water at rates

sufficient to supply reasonable amounts to wells.
24

Ground water is found in two types of aquifers--confined and unconfined. An unconfined 

(water-table) aquifer is not overlain by a confining 

unit. Unconfined aquifers in New Jersey generally 

are near land surface and are open to the atmosphere, 

and the water level rises and falls in response to infiltration of precipitation, discharge of ground water

and surface water, and climatic events (floods or

drought). In contrast, the pore spaces in a confined 

aquifer are completely filled with water. A confined

aquifer is overlain by a confining unit--a layer of

lower permeability that impedes the flow of water.

These layers typically are composed of small particles (silt or clay) or of rock that contains few or

poorly connected fractures.

Water generally enters the ground-water system where aquifers are present at or near land surface

(crop out). Water moves in response to the force of

gravity and differences in pressure. The combination 

of these forces is referred to as the hydraulic head.

Water that enters the aquifer moves toward a discharge point along pathways that are determined by 

hydraulic head and permeability. Some water may

move, or flow, horizontally through the aquifer, and

some may flow vertically through confining layers to

an aquifer below. Ground water eventually discharges to surface-water bodies such as streams,

lakes, the ocean, or wetlands, or to a well. The time

required for ground water to reach the discharge 

point depends on its flow path. Water that follows a 

relatively shallow, or local, flow path moves only 

short distances and may take only days to reach the 

discharge point, whereas water that follows a deeper, 

or regional, flow path moves long distances and may 

take centuries or millennia to reach the discharge 

point (fig. 9). Water may appear to flow upward at its 

discharge point as a result of the hydraulic head gradient (horizontal change in hydraulic head in a given 

direction), which causes water to move continuously 

from areas of higher hydraulic head (such as below a

stream) to areas of lower hydraulic head (such as in

a stream). When water is discharged to a stream or a 

well, it moves “downgradient” (from higher hydraulic head to lower hydraulic head), allowing more

water to move in behind it.

Ground water eventually 

discharges to surface-water

bodies such as streams, lakes, the 

ocean, or wetlands, or to a well.

PUMPED WELL

Water table

Unconfined

aquifer

Confined

aquifer

Confined

aquifer

Centuries

Millennia

Confining unit

Years

Days

Days

Years

RECHARGE AREA

DISCHARGE AREA Stream

Confining unit

Figure 9. Flow paths of ground water as it moves 

from recharge areas (hilltops) to discharge areas 

(streams, lakes, or wells) (modified from Heath, 

1983). The length of time it takes the water to move 

from recharge to discharge point depends on the flow 

path taken. Water traveling along local flow paths 

may take days to years to reach its discharge point. 

Water traveling along regional flow paths may take 

centuries to millennia.
25

Water quality

Water that reaches the land surface as precipitation either runs overland toward and into a stream

or percolates into the soil. Whatever its route, it

comes into contact with a wide variety of materials 

that can change its chemical composition. Flowing 

water breaks down rocks, dissolves minerals, picks

up sediments, reacts with soil materials and plant and 

animal matter, and carries the product in solution or

suspension (Swenson and Baldwin, 1965). The ability of water to dissolve many substances is determined by its temperature, its pH (acidity), and its

carbon dioxide content, which increases as carbon 

dioxide is absorbed from air or soil gases (Swenson 

and Baldwin, 1965). Water that percolates into the 

soil reacts with soil materials and plant and animal

matter, and dissolves minerals in the rocks. The type

and concentration of dissolved minerals in the water 

depends on the type of soil and rock through which 

it flows and the length of time the two were in contact. Ground water tends to contain higher concentrations of dissolved minerals than surface water 

because it moves much more slowly--typically on 

the order of feet per year, as opposed to feet per second for surface water. Also,some rocks are dissolved

more easily than others. For example, granite, sandstone, and shale are not very soluble in water, but

limestone and marble are more easily dissolved. 

Water quality also can be altered by soil bacteria, 

evaporation, and the effects of human activities, 

which can introduce physical, chemical, and biological contaminants associated with industry, agriculture, and municipal waste into ground and surface 

waters.

Wastewater treatment plant, New Brunswick,

New Jersey (Photograph by Eric Vowinkel)

Water quality determines the uses for which 

water is suitable. For example, water that is intended 

for human consumption generally must be of high 

quality and must meet Federal and State standards 

for drinking water (see section on Water-Quality 

Standards below). Water that contains high concentrations of certain constituents cannot appropriately 

be used for irrigation because these constituents may 

interfere with the uptake of nutrients by the plants

(Hem, 1985). Water that is not suitable for drinking 

may be suitable for other applications, such as industrial activities. And water that can be used for some

industrial activities--cooling, for example--may not 

be suitable for others, such as pharmaceutical manufacturing or food processing. 

In general, chemical characteristics of water

differ from place to place and are controlled by temperature, pressure, atmospheric deposition, the duration of contact with rocks and organic matter through 

or over which the water flows, and by human activities.

In general, chemical characteristics of water differ from 

place to place and are controlled by temperature, pressure, 

atmospheric deposition, the duration of contact with rocks 

and organic matter through or over which the water flows, 

and by human activities.
26

Water-quality standards

Water-quality standards are established by 

Federal and State governments to ensure that water 

is suitable for its intended use. Standards commonly

are specific to water use and differ for ground water,

surface water, and marine waters. Water-quality

standards are enforced to protect public health and 

welfare by ensuring the quality of water used for 

public supply, recreation, agriculture, industry, navigation, and ground-water recharge, and propagation 

of fish, shellfish, and wildlife (N.J. Department of

Environmental Protection, 1996b).

In New Jersey, all surface water is classified 

according to its designated use: swimming, boating,

shellfish harvesting, water supply, maintaining a fish

population, and supporting fish reproduction. The 

Federal Clean Water Act (P.L. 95-217) requires that

wherever possible the water-quality standards provide water suitable for fish, shellfish, and wildlife to 

thrive and reproduce and for people to swim and boat 

(N.J. Department of Environmental Protection,

1996b). Some classes of waters, such as freshwater 

streams, are further divided. These can be separated 

into trout-producing waters, trout-maintenance 

waters, and non-trout waters. These waters are classified on the basis of trout habitat because the species 

is a highly desirable game fish and is especially sensitive to temperature changes, habitat, and contaminants (J.G. Kennen, U.S. Geological Survey, oral

commun., 1999). Each classification has a corresponding set of water-quality criteria, or numerical 

concentration values for various constituents, that

must be met.

Boating in the Manasquan Inlet. (Photograph by 

Robert Nicholson)

Water-quality standards are enforced to protect public 

health and welfare by ensuring the quality of water used 

for public supply, recreation, agriculture, industry,

navigation, and ground-water recharge, and propagation

of fish, shellfish, and wildlife.
27

The relation among designated water use,

classification, and quality criteria is shown in figure 

10. For example, one designated use is primary and 

secondary recreation (swimming and boating,

respectively). Water classifications that must meet 

this designated use are all freshwater streams (coded 

FW-1 and FW-2), saline-water estuaries (coded SE1), saline coastal waters (coded SC), and Pinelands 

waters (coded PL). Each of these classifications, 

except FW-1, is associated with a specific set of criteria. FW-1 is freshwater that originates in and is

wholly within Federal or State parks, forests, fish

and wildlife lands, or special holdings. These waters

are to be maintained in their natural state and not

subjected to any wastewater discharges (N.J. Department of Environmental Protection, 1998b).

The current State ground-water-quality standards were established by NJDEP in January 1993. 

These standards are intended to protect the integrity 

of the aquifer for its intended use. Asin the approach

used for the surface-water-quality standards, designated uses are assigned to the ground-water 

resources and numerical criteria to support those 

uses are provided. The designated uses include Class

I (waters of ecological significance, such as in the

Pinelands areas); Class II (drinking-water supplies); 

and Class III (waters used for purposes other than

drinking, such as industrial cooling). Criteria for 

Class II waters are based on the protection of human 

health from exposure to contaminants by consumption of drinking water. The ground-water-quality criteria are used by the NJDEP to regulate groundwater quality by setting standards for discharges to

ground water and for ground-water restoration. The 

ground-water standards also take into account the

interaction between ground water and surface water.

Because streamflow in many parts of the State is

derived mainly from ground water, protection of the 

ground-water resource is crucial to the maintenance

of surface-water quality. (See N.J. Department of 

Environmental Protection, 1996b.)

PRIMARY OR

FW-1

FW-2

SE-1

SC

PL

SECONDARY

RECREATION

DESIGNATED USE

CLASSIFICATION CRITERION: pH

3.5-5.5

Natural conditions prevail

SELECTED

6.5-8.5

6.5-8.5

No change from natural

Figure 10. Example of N.J. Department of 

Environmental Protection water-quality standards, 

classifications, and criteria. N.J. Department of 

Environmental Protection water-quality standards are 

established to protect human health and maintain the

integrity of the State’s water resources. Standards are 

made up of a combination of regulations consisting of 

policy, designated water use, classification, and 

criteria. Designated water uses include swimming, 

boating, maintaining fish, supporting fish reproduction, 

and potable public water supply. Surface-water 

classifications are freshwater (FW-1, FW-2), saline 

estuaries (SE-1), saline coastal (SC), and Pinelands 

(PL). Each classification except FW-1 has a specific 

set of criteria, or numerical guidelines, that must be 

met. pH, one of the 138 properties and constituents 

for which criteria have been established, is shown 

in the example above. The pH criteria for FW-2 and 

SE-1 are the same but the pH criteria for SC and PL

are different. Criteria for other properties and 

constituents also may vary depending on the 

classification (N.J. Department of Environmental 

Protection, 1996a).

conditions (non-degradation)

Because streamflow in many parts of the State is 

derived mainly from ground water, protection of the 

ground-water resource is crucial to the maintenance 

of surface-water quality.
28

Drinking-water criteria are applied only to

water to be used specifically for human consumption 

and the source of the water may be surface and (or)

ground water. Primary drinking-water standards for

treated ground and surface waters are the maximum

allowable constituent concentrations, called 

“MCL’s” (maximum contaminant levels), which are

set to protect human health by limiting concentrations of inorganic chemical contaminants, organic

chemical contaminants, microbiologic and radiologic contaminants, and turbidity in public drinking

water (table 2). These contaminants may occur naturally or may be derived from domestic and (or)

industrial discharges (N.J. Department of Environmental Protection, 1998c). MCL’s are based on (1)

adverse health effects, (2) availability of instruments

to detect the constituent in drinking water, and (3)

knowledge that the constituent can occur in drinking

water (Susan Lance and Theodore B. Shelton, Rutgers Cooperative Extension, New Jersey Agriculture

Experiment Station, New Brunswick, N.J., Fact

Sheet 433, accessed July 1, 1999, on the World Wide 

Web at URL http://www.rce.rutgers.edu/ag/agnaturalresources, text format). Action levels (AL’s) are 

set for lead and copper in public drinking supplies. If

an AL is exceeded, the operators of a water system 

are required to provide corrosion-control treatment,

monitor source water for concentrations of lead and 

copper, replace lead service lines, and notify the

public. 

Secondary drinking-water standards are set for 

aesthetic rather than health reasons, and include limits on such water characteristics as offensive taste, 

odor, corrosivity, and foaming or staining. These 

standards are recommended but not enforced. 

Federal law states that all community public

water supplies must be tested on a rigid schedule at

specific locations. Private well owners are under no 

Federal or State regulations to test their own wells, 

but NJDEP recommends that homeowners arrange

for annual testing for bacteria, nitrates, and lead. 

(See N.J. Department of Environmental Protection,

1994.)

Water use

In New Jersey, water is used for public, industrial, domestic, and commercial supply, in addition to

irrigation, mining, and thermoelectric-power generation. The source of your water depends on where you

live, how populated the area is, and what the geology 

is like. About 73 percent of all water used in New

Jersey is surface water and about 27 percent is

ground water (Nawyn, 1997). Public supply is the 

largest use category; in northern New Jersey, about

85 percent of the water used for public supply is surface water and 15 percent is ground water. In southern New Jersey, the percentages are reversed--15 

percent is surface water and 85 percent is ground

water (J.P. Nawyn, U.S. Geological Survey, written 

commun., 1999). This is the result of several factors. 

Northern New Jersey is densely populated, and 

ground water is concentrated in rock fractures, bedding planes, and solution cavities in the carbonate

rocks. Because the ground water is not uniformly 

distributed, it is less accessible than the ground water 

in southern New Jersey. In some areas, the quality of

the ground water may be unsuitable for particular

uses. Reservoirs are heavily used and water-transferring systems are used to transfer water from the more

pristine rural areas to urban centers. Southern New

Jersey is less densely populated, and aquifers are

able to store and produce large amounts of ground 

water. In addition, well drilling is easier in the 

unconsolidated sediments of southern New Jersey 

than in the consolidated rocks of northern New

Jersey.
2

9

Contaminant

Drinking-water

standard

MCL

Volatile Organic Compounds

Benzene 1Carbon tetrachloride 2meta-Dichlorobenzene 600ortho-Dichlorobenzene 600para-Dichlorobenzene 751,1-Dichloroethane 501,2-Dichloroethane 21,1-Dichloroethylene 2cis-1,2-Dichloroethylene 70trans-1,2-Dichloroethylene 1001,2-Dichloropropane 5Ethylbenzene 700Methyl tertiary butyl ether 70Methylene chloride 3Monochlorobenzene 50Naphthalene 300Styrene 1001,1,2,2-Tetrachloroethane 1Tetrachloroethylene 1Toluene 1,0001,2,4-Trichlorobenzene 91,1,1-Trichloroethane 301,1,2-Trichloroethane 3Trichloroethylene 1Vinyl chloride 2Xylenes [total] 1,000

MCL--Continued

Inorganic Contaminants

Antimony 6Arsenic 50Asbestos [7x106 fibers/liter] >10 *Barium 2,000Beryllium 4Cadmium 5Chromium 100Copper 1,300 [AL]Cyanide 200Fluoride 4,000Lead 15 [AL]Mercury 2Nickel --Nitrate [as nitrogen] 10,000Nitrite 1,000Nitrate plus nitrite 10,000Selenium 50Thallium 2

Synthetic Organic Compounds

Alachlor 2Aldicarb --Aldicarb sulfone --Aldicarb sulfoxide --Atrazine 3Benzo[a]pyrene .2Carbofuran 40

Contaminant

Drinking-water

standard

Synthetic Organic Co

Chlorodane Dalapon DibromochloropDi[2-ethylhexyl]Di[2-ethylhexyl]Dinoseb Diquat Endothall Endrin Ethylene dibromGlyphosate Heptachlor Heptachlor epoxHexachlorobenzHexachlorocycloLindane Methoxychlor Oxamyl Polychlorinated PentachlorophenPicloram Simazine Toxaphene 2,3,7,8-TCDD [D2,4-D 2,4,5-TP [Silvex

Contam

Table 2. U.S. Environmental Protection Agency and New Jersey State primary and secondary drinking-water standards as o[Data from N.J. Department of Environmental Protection, 1997a; MCL, maximum contaminant level; all MCL’s are in micrograms per liter ( g/L) which is equivalent to 

noted; SMCL, secondary maximum contaminant level; all SMCL’s are in milligrams per liter (parts per million) unless otherwise noted; *, in micrometers; AL, action leveremedial action is to take place; pCi/L, picocuries per liter; --, no MCL but monitoring required; NTU, nephelometric turbidity unit; ABS/LAS, Alkyl-Benzene-Sulfate anene Blue Reactive Substances contained in synthetic detergents; >, greater than]
30

MCL--Continued

Additional Contaminants

Trihalomethanes--Total of dichlorobromomethane, chlorodibromomethane, bromoform, and

chloroform

100 g/L [ppb]

annual average

Radionuclides

Radium-226 + radium-228Gross alpha-particle activity

[including radium-226 butexcluding radon and uranium]

5 pCi/L

15 pCi/L

Coliform bacteria (sample amount

depends on size of public-supply system)40 samples per month or moreless than 40 samples per month

coliform no greaterthan 5 percent of sampleno more positivethan one sample forcoliform

Contaminant

Drinking-water

standard

SMCL

Physical Characteristics

Color 10 color units (standard cobalt scale)pH 6.5 to 8.5

(optimum range)

Odor 3 (threshold odor

number)

Taste No objectionable

taste

Turbidity (in NTU) No more than 5 percent of the samples 

may exceed 0.5 NTU, nor any sample exceed 5 NTU

Contaminant

Drinking-water

standard

Chemical Characterist

ABS/LAS (foamiAluminum Chloride Dissolved solids Fluoride Hardness (as CaCIron Manganese Silver Sodium Sulfate Zinc 

Contam

Table 2. U.S. Environmental Protection Agency and New Jersey State primary and secondary drinking-water standards as of 
31

Water use in New Jersey by category is shown

in figure 11. Domestic supply includes public water 

supply from both ground-water and surface-water

sources, and water used in rural homes with wells 

(ground water only). Thermoelectric-power generation and domestic supply are the largest categories of

use and together account for almost 60 percent of the 

water used in New Jersey. They are followed by

industrial use, unaccounted-for water (losses) and 

public use, and commercial use. Unaccounted-for

water includes leaks to water systems, unauthorized

connections, and improperly running meters. Public

use is water used in parks, schools, and offices and 

for fire protection (Nawyn, 1997). Irrigation and 

mining are the smallest use categories. Water for

these uses is derived only from surface water and 

self-supplied ground water. Water used for all other 

purposes is self-supplied ground water, surface 

water, or publicly supplied water.

Ground- and surface-water withdrawals in

New Jersey by water region are shown in figure 12. 

Total water use is divided into ground-water and surface-water components of public-supply and “other”

uses, which include commercial, irrigation, thermoelectric-power generation, mining, and industrial

uses. 

Domestic

Commercial

Irrigation

Industrial

Mining

Thermoelectric power Unclassified 

use

Figure 11. Water used in New Jersey in 1994, by use 

category. Domestic use includes publicly supplied 

water and water from wells. Publicly supplied water 

can be from ground-water or surface-water sources. 

Commercial, industrial, and thermoelectric uses are 

made up of publicly supplied water and self-supplied 

ground and surface water. Water used for mining and 

irrigation is only self-supplied ground and surface 

water. Domestic and thermoelectric use are the 

largest use categories, followed by industrial and 

unaccounted-for water (losses) and public use. Unaccounted-for water includes leaks to water systems, 

improperly running meters, and unauthorized hookups. 

Public uses include water used for fire protection and 

water used in parks, offices, and schools. (Data from 

Nawyn, 1997)

Unaccounted-for 

water (losses) 

and public use
32

GW-Public

14%

SW-Public

82%

GW-Other

2.1%

SW-Other

1.1%

GW-Public

5.7%

SW-Public

45%

GW-Other

5.3%

SW-Other

44%

Northeast Northwest

GW-Public

34%

SW-Public

54%

GW-Other

10%

SW-Other

1.5%

GW-Public

18%

SW-Public

0.5%

GW-Other

4.6%

SW-Other

77%

GW-Public

42%

SW-Public

16%

GW-Other

6.0%

SW-Other

37%

Raritan Lower Delaware

Atlantic Coastal

Figure 12. Ground-water (GW) and surface-water (SW)

withdrawals in the five water regions of New Jersey. 

Withdrawals are divided into public supply and "other," 

which includes irrigation, commercial, mining, thermoelectric-power, and industrial withdrawals. The Northeast 

and Raritan water regions are dominated by public-supply 

withdrawals from both ground and surface water. The 

Lower Delaware water region is dominated by withdrawals 

for thermoelectric-power generation. In the Northwest 

water region, large amounts of surface water are withdrawn 

for public supply from the Delaware River and routed to the 

Delaware and Raritan Canal to supply the population in 

other water regions. Additional water is withdrawn from the 

Delaware River for thermoelectric-power generation and 

industrial use, which make up the "surface-water other" 

category. In the Atlantic Coastal water region, ground water 

used for public supply and surface water used for irrigation 

and industry are the largest withdrawal categories.
33

Public supply use is most prevalent in the

Northeast and Raritan water regions. Large amounts 

of surface water are withdrawn from the Delaware

River in the Northwest water region but not used by 

the population in the water region. This water is

transported through the D and R Canal to other water 

regions. The large “other” surface-water component

in the Northwest water region consists of withdrawals for industrial use and thermoelectric-power generation. Water use in the Lower Delaware water 

region is dominated by thermoelectric-power generation, which appears in the surface-water “other”

category. This water is withdrawn from the Delaware

River and used in power plants for cooling. In the

Atlantic Coastal water region, ground water used for

public supply predominates, although surface-water

withdrawals in the “other” category, largely for irrigation and industry, also are a large component.

An important factor when considering water

use is consumptive use. Consumptive use is that part

of water withdrawn that is evaporated, transpired,

incorporated into products or crops, consumed by

people or livestock, or otherwise removed from the 

immediate environment (Solley and others, 1998). 

The percentage of total water use that becomes consumptive use depends on what the water is used for 

and how it is treated after use. For example, of the 

water withdrawn for public supply or domestic supply, only 18 percent is consumed. The rest is returned

to the ground-water or surface-watersystem. This 18 

percent will become 100-percent consumptive if the 

water used is sent to a sewage-treatment plant that

discharges treated water directly to the ocean. Water 

withdrawn for industrial, mining, and thermoelectric-power generation purposes are 8 percent, 10 percent, and virtually non-consumptive, respectively. 

The consumptive-use value is important because the 

largest water-use categories (public supply and thermoelectric-power generation) are not the largest consumptive users. Irrigation, on the other hand, is one 

of the smallest water-use categories in New Jersey, 

but most irrigation water use is consumptive.Water

withdrawn for irrigation is 90-percent consumptive

because of evaporation and the uptake by the plants;

therefore, very little water is returned to the system. 
34

New Jersey can be divided into five water

regions--the Northeast, Raritan, Northwest, Lower

Delaware, and Atlantic Coastal water regions. The

five water regions are divided into 20 watershedmanagement areas, which are subdivided into more

than 100 individual watersheds (figs. 1 and 2a-e). 

These management categories were established by

the NJDEP in January 1997 to facilitate the use of a 

“watershed-management approach” to managing

and protecting New Jersey’s water resources.

Geology and hydrology

New Jersey can be divided geologically into

northern and southern parts by the Fall Line. North 

of the Fall Line are the Valley and Ridge, New 

England (also called the Highlands), and Piedmont

Physiographic Provinces. South of the Fall Line is

the Coastal Plain Physiographic Province (fig. 13). 

The Fall Line roughly parallels U.S. Route 1 from 

Trenton to New York City and is marked by a series 

of waterfalls along river courses. The Fall Line also

is the boundary between older, resistant consolidated

rocks to the northwest and younger, weaker, unconsolidated sediments to the southeast. Each physiographic province has distinct geologic and

hydrologic characteristics. Because the hydrologic

characteristics of aquifers and confining units are 

defined by geologic properties such as grain

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

Valley and Ridge

New England

Piedmont

Fall Line

Coastal Plain

Extent of 

Wisconsin

glaciation

Figure 13. New Jersey spans parts of four physiographic provinces. Aquifers in the northern three 

physiographic provinces are composed of glacial 

valley-fill deposits and fractured shales, limestones, 

sandstones, conglomerates, and crystalline rock. 

Aquifers in the Coastal Plain consist of unconsolidated sands and gravel. 

New Jersey can be divided into five water regions--

the Northeast, Raritan, Northwest, Lower Delaware,

and Atlantic Coastal water regions.

New Jersey can be divided geologically into northern and 

southern parts by the Fall Line. North of the Fall Line are the 

Valley and Ridge, New England (also called the Highlands), 

and Piedmont Physiographic Provinces. South of the Fall Line

is the Coastal Plain Physiographic Province.

DESCRIPTION OF THE STUDY AREA
35

Springers Brook near Indian Mills, New Jersey.

(Photograph by Robert Nicholson)

size, sorting, and resistance to erosion and fracturing, geology exerts considerable control over 

ground-water hydrology. North of the Fall Line, 

aquifers and confining units are composed of glacial

valley-fill deposits, fractured shale, limestone, sandstone, conglomerate, and crystalline-rock units;

south of the Fall Line, they consist of unconsolidated 

gravels, sands, and clays.

Geology also controls stream characteristics to

a large extent. Streams in the physiographic provinces north of the Fall Line, such as West Brook near

Wanaque, New Jersey, tend to have steep gradients

with rocky bottom material, whereas those in the 

Coastal Plain Physiographic Province, such as

Springers Brook near Indian Mills, New Jersey, are 

characterized by sandier streambeds and gentler 

slopes. Rocky bottom material tends to impede

West Brook near Wanaque, New Jersey.

(Photographer unknown)

streamflow as a result of friction between the water 

and the stream channel. Stream velocity tends to be 

greater in steep channels than in those with gentler 

slopes.

The interaction of water, wind, temperature,

and pressure with rocks and sediments is a degenerative geologic process called weathering. Plants also

contribute to weathering by helping to break down 

the rocks and sediments.Weathered rock material is

the basic ingredient of soils (Keller, 1979, p. 51). 

(See Box B.) 

As glaciers moved into New Jersey from New

York State, they picked up and transported rocks and 

sediment. The northern physiographic provinces 

were covered by glaciers several times; the last glaciers receded about 20,000 years ago. The “Wisconsinan” glacier left behind deposits of “glacial drift”

and “till.” The degree of sorting of a glacial drift

determines its water-holding and -transmitting properties. Drift that is not well-sorted and contains large 

amounts of fine-grained material such assilt and clay 

acts as a confining unit. Drift that is well-sorted and

contains predominantly layers of sand and gravel is

called “stratified drift” and makes an excellent aquifer. “Till” is a mix of unsorted clay, silt, sand, gravel, 

and boulders. In upland areas till is generally 30 to 

40 ft (feet) thick, but in the valleys and lowlands,
36

Soils and their relation to the hydrologic system

 Soils, together with climate, geology, and topography, determine the hydrologic characteristics of 

a watershed (Ayers and others, 1994). Soils influence the amount of and speed with which water

infiltrates into the ground. Sandy soils allow more water to infiltrate, and at a faster rate, than

clayey soils. Clayey soils tend to cause pooling of precipitation on the land surface, resulting in 

overland flow. Clayey soils also tend to retain rather than transmit water. The amount of water that is 

retained in the soil affects its ability to sustain plant growth, and minerals in the soil can be 

dissolved and affect the quality of the water moving through it.

 The Natural Resources Conservation Service (NRCS) conducts soil surveys and produces maps 

that show the location and extent of soils in an area. Shown is an example of a soil map of part

of Morris County, N.J. Soil surveys provide information on the physical and chemical properties 

of the soils that is needed by community planners, engineers, scientists, and farmers. Soil surveys 

are the basis for predicting the behavior of soil under alternative uses, its potential for erosion, the

degree to which it will allow contaminated water from the land surface to infiltrate and recharge

the water table, and its suitability for cultivating crops, trees, and grasses (National Resources

Conservation Service, U.S. Department of Agriculture, unpub. data accessed January 13, 1999,

on the World Wide Web at URL http://www.nrcs.usda.gov/NRCSprog.html, text format).

B

36
Adrian muck

Annandale gravelly loam, 3 to 8 percent slopes

Annandale gravelly loam, 8 to 15 percent slopes

Bartley loam, 3 to 8 percent slopes

Bartley loam, 8 to 15 percent slopes

Bartley gravelly loam, 8 to 15 percent slopes

Biddeford silt loam

Boonton and Haledon extremely stony soils, 8 to 15 percent slopes

Carlisle muck

Cokesbury gravelly loam, 0 to 3 percent slopes

Edneyville gravelly loam, 3 to 8 percent slopes

Edneyville gravelly loam, 8 to 15 percent slopes

Hibernia stony loam, 3 to 15 percent slopes

Made land

Muck, shallow over clay

Natcong gravelly sandy loam, 3 to 8 percent slopes

Natcong gravelly sandy loam, 8 to 15 percent slopes

Otisville gravelly loamy sand, 3 to 15 percent slopes

Parker gravelly sandy loam, 3 to 15 percent slopes

Parker very gravelly sandy loam, 15 to 25 percent slopes

Parker-Edneyville extremely stony sandy loam, 3 to 15 percent slopes

Parker-Edneyville extremely stony sandy loam, 15 to 25 percent slopes

Parker-Rock outcrop complex, 20 to 35 percent slopes

Pits, sand and gravel

Pompton sandy loam, 0 to 3 percent slopes

Pompton sandy loam, 3 to 8 percent slopes

Preakness sandy loam, 0 to 4 percent slopes

Preakness sandy loam, dark surface variant

Ridgebury extremely stony loam, 3 to 10 percent slopes

Riverhead gravelly sandy loam, 0 to 3 percent slopes

Riverhead gravelly sandy loam, 3 to 8 percent slopes

Riverhead gravelly sandy loam, 8 to 15 percent slopes

Rockaway gravelly sandy loam, 3 to 8 percent slopes

Rockaway very stony sandy loam, 3 to 15 percent slopes

Rockaway extremely stony sandy loam, 15 to 25 percent slopes

Rock outcrop-Rockaway comlex, steep

Turbetville loam, 0 to 3 percent slopes

Turbetville loam, 3 to 8 percent slopes

Urban land

Urban land-Riverhead complex

Urban land-Rockaway complex, gently sloping

Water

Example soils map of a part of Morris County, New Jersey

EXPLANATION

Kenvil

Succasunna

Mine Hill

MINE HILL

TOWNSHIP

CHESTER 

TOWNSHIP

RANDOLPH TOWNSHIP

ROXBURY

TOWNSHIP

Route 46

Route 10

Route 513
38

deposits of sand and gravel can be as much as 350 ft

thick (U.S. Geological Survey, 1985) (fig. 14). Stratified sand and gravel deposits can be highly productive aquifers and may yield more than 2,000 gal/min 

(gallons per minute) to a well (table 3). Wells that are 

completed in these aquifers typically are used for 

public and industrial supply (U.S. Geological Survey, 1985).

The part of the Valley and Ridge Physiographic Province that lies within New Jersey is

located in the northwesternmost part of the State and 

is totally encompassed by the Northwest water

region (fig. 13). This area is characterized by long, 

parallel, northeast-southwest-trending ridges and 

valleys that generally are formed by erosion-resistant sandstone and shale and easily eroded limestone, respectively. In this area, the carbonate rocks

(limestones) are the most productive aquifers, especially where they are covered by glacial deposits

(U.S. Geological Survey, 1985). Solution channels

and cavities in the limestones can hold and transmit

large amounts of water. The sandstones and the

shales may or may not be productive, depending on

the amount of weathering and fracturing they have

undergone.

The part of the New England (Highlands)

Physiographic Province that lies within New Jersey 

covers parts of the Northwest, Northeast, and Raritan 

water regions (fig. 13). This province contains the 

oldest rocks in New Jersey. The sedimentary rocks 

deposited in this province were subjected to high 

heat and pressure, were intensely deformed, and 

have recrystallized into granites, gneisses, and a

small amount of marble. The granite and gneisses are 

resistant to erosion and generally are poor aquifers

except where they are weathered and fractured.

Some valleys in this province are underlain by carbonate rocks that can be highly productive aquifers. 

Glacial deposits in this area also are productive aquifers.

The part of the Piedmont Physiographic Province that lies within New Jersey covers parts of the 

Northwest, Northeast, and Raritan water regions

(fig. 13). In New Jersey, the Piedmont is separated

from the New England Physiographic Province by 

major faults. The Piedmont is characterized by interbedded sandstone, shale, conglomerate, basalt, and 

diabase (fig. 14). Water is found in the joints and 

fractures of the shales and sandstones, typically in

the upper 200 to 300 ft. Coarse-grained sandstones 

also hold water in the pore spaces between the sand 

grains. The aquifers in this area can yield as much as

1,500 gal/min to wells (table 3). 

The part of the Coastal Plain Physiographic

Province that lies within New Jersey, covers about 

4,200 mi2

 (fig. 13) and encompasses the Atlantic

Coastal and Lower Delaware water regions, as well

as the southernmost parts of the Northwest and Raritan water regions. The Coastal Plain is characterized

by a seaward-thickening wedge of unconsolidated 

sediments that starts as a featheredge at the Fall Line 

and reaches a thickness of about 6,500 ft in southern

Cape May County (Zapecza, 1989). The sediments 

are composed of alternating layers of clay, silt, sand, 

and gravel; the layers of sand and gravel are aquifers 

and the layers composed predominantly of silts and 

clays are confining units (fig. 14). Five principal 

aquifers underlie the Coastal Plain: the KirkwoodCohansey aquifer system, the Atlantic City 800-foot 

sand, the Wenonah-Mount Laurel aquifer, the 

Englishtown aquifer system, and the Potomac-Raritan-Magothy aquifer system (table 3). The Kirkwood-Cohansey aquifer system is unconfined; the 

other aquifers are confined except where they reach 

the surface or are overlain by permeable surficial 

deposits (U.S. Geological Survey, 1985). The Kirkwood-Cohansey aquifer system underlies 3,000 mi2

of the Coastal Plain. The sands and gravels of this

aquifer system make it an excellent source of water 

and well yields can be as high as 1,500 gal/min.

Streams and other surface-water features generally 

are in good hydraulic connection with the KirkwoodCohansey aquifer system, making it an important

component of watershed management in the Coastal

Plain. The Potomac-Raritan-Magothy aquifer system is the most productive aquifer system and the 

most extensively used confined aquifer system in the

Coastal Plain in New Jersey (U.S. Geological Survey, 1985). It is found throughout the Coastal Plain

but is used most heavily along the Delaware River 

from Mercer County to Salem County and along the 

Raritan Bay in Middlesex County. Withdrawal rates 

from individual wells in this aquifer are as high as

2,000 gal/min (table 3).
3

9D

Downdip Basalt/diabase

Stream

Bedding plane Sandstone and shale

Stream

Stream

Wate

B

Wetland

Bedrock

WEST

Delaware

River

Confining unit

Water table Stream

A

Figure 14. Schematic diagrams of ground-water flow systems in four representative hydrogeologic terrains in New Jersey: (A) usystems of the Coastal Plain, (B) outcrop areas of confined aquifers in the Coastal Plain, (C) glacial valley-fill aquifers of northeand (D) fractured sedimentary-rock aquifers of the Newark Basin. (From H.T. Buxton, U.S. Geological Survey, written commun.

 Aquifer

Sandstone

and siltstone

C

 Water table

Glacial aquifer

Confining unit

Limestone or shale

Confin

Cross-valley
40

Table 3. Characteristics of aquifers and wells in New Jersey

[Data from U. S. Geological Survey, 1985; ft, feet; mi, miles; gal/min, gallons per minute; Mgal/d, million gallons per day; --, data

unavailable]

Aquifer name and description

Aquifer 

withdrawals 

in 1980 

(Mgal/d)

Well characteristics

Remarks

Depth

below land

surface (ft)

Yield (gal/min)

Common range May exceed

Coastal Plain aquifers

Kirkwood-Cohansey aquifer system:

Sand, quartz, fine- to coarsegrained, pebbly; local clay beds.

Unconfined.

70 20 - 350 500 - 1,000 1,500 Ground water is generally under water-table

conditions. Aquifer system extends from

southern Monmouth County to Delaware Bay 

and from 12 mi southeast of the Delaware

River to the Atlantic Ocean. Aquifer

thickness can exceed 350 ft. Brackish and 

salty water may occur in coastal areas.

Atlantic City 800-foot sand: Sand,

quartz, medium- to coarse-grained, gravel, fragmented shell material.

Confined.

20 450 - 950 600 - 800 1,000 Principal confined artesian aquifer supplying 

water along the barrier beaches in Cape May, Atlantic, and Ocean Counties. Aquifer

thickness generally ranges between 100 and 

150 ft. Water quality suitable for most uses.

Wenonah-Mount Laurel aquifer: Sand,

quartz, slightly glauconitic, very

fine- to coarse-grained, layers of

shells. Confined.

5 50 - 600 50 - 250 500 Important confined aquifer in the northeastern

and southwestern parts of the Coastal Plain.

Aquifer thickness generally ranges between

60 and 120 ft. Water quality suitable for most

purposes.

Englishtown aquifer system: Sand,

quartz, fine- to medium-grained, 

local clay beds. Confined.

12 50 - 1,000 300 - 500 1,000 Important source of water for Ocean and

Monmouth Counties. Confined aquifer

thickness generally ranges between 60 and 

140 ft. Excellent water quality.

Potomac-Raritan-Magothy aquifer

system: Alternating layers of gravel,

sand, silt, and clay. Confined.

243 50 - 1,800 500 - 1,000 2,000 Highly productive and most used confined

aquifers in the Coastal Plain. Aquifer system

extends throughout Coastal Plain and attains 

maximum thickness of 4,100 ft. Includes two aquifers in northern Coastal Plain: Farrington

and Old Bridge aquifers. Salty water

increases with depth and in downdip 

direction. Excellent water quality but large

iron concentrations in some areas.

Non-Coastal Plain aquifers

Glacial valley-fill aquifers: Sand,

gravel, interbedded silt and clay. 

Generally unconfined except where

overlain by lake silt and clay or till.

-- 10 - 300 100- 1,000 2,000 North of terminal moraine, these aquifers occur 

principally as channel fill in preglacial stream

valleys; south of the moraine, they occur as

outwash plains and valley trains. Important 

aquifers in Bergen, Essex, and Morris

Counties. Water quality suitable for most

uses.

Aquifers in the Newark Group: Shale, sandstone, some conglomerate.

Unconfined to partially confined in

upper 200 ft; confined at greater

depth.

-- 30 - 1,500 10 - 500 1,500 Most productive aquifers in Essex, Passaic, and 

Union Counties. Water generally hard; may 

have large concentrations of iron and sulfate.

Saltwater has intruded into areas of large 

ground-water withdrawal near bays and 

estuaries.

Valley and Ridge sedimentary units: 

Predominantly limestone and shale;

some dolomite, calcareous

sandstone and siltstone, sandstone,

conglomerate, and slate. Confined

and unconfined.

-- 150 - 400 5 - 500 1,500 Highest yields from cavernous limestones and 

from weathered and fractured zone within 300 

ft of land surface. Locally excessive iron

concentrations and hardness, and low pH.

New England crystalline units: Gneiss,

marble, quartzite, pegmatite; some

schist, amphibolite, and granite.

Includes thin belts of conglomerate

and sandstone; not significant as

aquifers. Confined and unconfined.

-- 35 - 800 5 - 50 400 Most water obtained from weathered and 

fractured zone in upper 300 ft; high yields in 

or near major fault zones. Excellent source of

water for domestic use in some areas.
41

Land use

Land use can affect the quality, quantity, and

distribution of water recharging an aquifer or running overland to streams (Winters and others, 1998). 

An increase in impervious surfaces such as parking 

lots, buildings, and roads decreases the amount of

land through which precipitation can recharge the 

aquifer. Water that cannot infiltrate into the ground 

increases the amount of overland flow, with the

potential for an increase in soil erosion, flooding, and 

surface-water contamination. Water quality in a 

watershed typically decreases as development 

increases. In rural and agricultural areas, septic systems can introduce contaminants to the ground 

water, feedlots may leach fecal matter into the soil,

and pesticides used on farm fields can enter the 

ground- and surface-water systems. In suburban 

areas, pesticides or herbicides used on home lawns 

and rights-of-way can enter the water supply. In cities, industries may discharge waste to streams, and 

runoff from roads can transport oil and gasoline residue as well as salt used (in the winter) for deicing to 

streams--all of which degrade water quality. The use

of large amounts of water for irrigation and urban 

and industrial use can reduce the quantity of water 

available. Water may have to be withdrawn from a 

nearby stream, pumped from an underlying aquifer,

or brought in from a neighboring area to supplement

the water supply. Pumping water directly from a 

stream, however, decreases streamflow, changes the 

ecological habitat of the stream, and reduces the

amount of water available to dilute any contaminants

that may be present. Pumping water from an underlying aquifer may decrease ground-water levels and

cause water to flow from streams into the aquifer,

bringing contaminants along with it. Importing water

from neighboring watersheds may raise the water

level excessively in some areas, causing flooding.

Industrial and residential land use along the

lower Delaware River in New Jersey. (File 

photograph, U.S. Geological Survey, West

Trenton, New Jersey)

Land use can affect the quality, quantity, and distribution of water 

recharging an aquifer or running overland to streams. 
42

All of these examples represent changes in the

distribution of water in a watershed. Decreasing 

streamflow in one location will affect flow at all sites 

downstream. Lowering the water level in an aquifer 

in one area will force pumped wells to draw water

from farther and farther away, lowering the water 

level in adjacent areas. Watershed protection programs can help to monitor land-use activities, development, and water use, ultimately protecting the 

quality and quantity of water in the watershed. Land

use in New Jersey in 1991-93 is shown in figure 15. 

This is a computer plot derived from a geographic 

information system file. (See Box C.) The northeastern part of the State contains several large urban 

areas, with smaller centers located around Trenton, 

Camden, and the Atlantic Shore. Northwestern New 

Jersey is predominantly forested and southern New 

Jersey is both agricultural and forested. 

Watershed protection programs 

can help to monitor land-use

activities, development, and 

water use, ultimately protecting 

the quality and quantity of 

water in the watershed.
43

Figure 15. Land use in New Jersey, 1991-93. The large population centers are located in 

the northeastern part of the State and along the Delaware River. Northwestern New Jersey 

is predominantly forested. Southern New Jersey is predominantly agricultural and forested.

Land-use information is useful for documenting changes over time, for identifying potential

risks to ground and surface water, and for water-management planning.
44

 Aerial photography and remote sensing have long been applied to problems in the earth sciences,

such as geologic and topographic mapping (Campbell, 1987). Now cartographic (mapping) tools, 

such as geographic information systems (GIS), and new imaging techniques such as digital orthophoto quadrangle maps, digital raster graphics, and satellite imaging, are available to help scientists 

and engineers conduct hydrologic studies. Coupled with land-use maps, these map images allow 

researchers and planners to accurately document land-use changes in a given area over time. 

Examples of these types of maps of an area near the Mercer County Airport in central New Jersey

are shown here.

 Digital raster graphics are scanned images of a USGS topographic map. The lines on the map are 

"georeferenced" to the surface of the Earth (related to a specific geographic position in the world, 

such as a specific latitude and longitude). These maps can be used as a base on which to plot 

additional digital data (U.S. Geological Survey, 1996b). 

 Digital orthophotos are digital maps of aerial photographs with any displacement caused by the 

camera or the relief of the terrain removed (U.S. Geological Survey, 1996a). The image has the 

characteristics of a photograph and the geometric qualities of a map. The accuracy and detail of 

these images make them easy and invaluable to work with. They can be used to study environmental 

effects on ground water and surface water, devise emergency evacuation plans, analyze floods, and 

document soil erosion. Digital orthophotos can be easily rescaled and reformatted, and additional 

information, such as roads or water-level contours, can be superimposed to meet the user's needs.

 The land-use map shown was produced from satellite images that measure the solar radiation 

reflected from the Earth’s surface. Satellite images have advantages over aerial photographs in 

that large areas can be seen in a single image, distortion is minimized, and multiple images of the 

same area are available (Campbell, 1987). This land-use map was created by thematic mapper 

imaging, which is a satellite-based method of data collection. The land-use image, which has a 

30-meter by 30-meter resolution, was analyzed and interpreted by using statistical methods to 

determine the predominant land use (urban, agriculture, forest, or water) in each 30-meter by 

30-meter cell. 

 Common features can be seen in the three plots of the same area. The airstrip in the upper left 

is seen as an "X" on the digital raster graphic and digital orthophoto maps and as urban land on 

the land-use map. The railroad tracks through the center of the plots are lined by trees (green on 

the upper half of the land-use map), and the areas of urban and agricultural land can be discerned 

on each map.

C

Cartographic tools used in hydrologic studies

44
45

A digital raster graphic is a scanned image of

a U.S. Geological Survey topographic map.

This land-use information is from thematic 

mapper images (satellite imagery). 

Urban

Agriculture

Forest

Water/wetlands

LAND USE/LAND COVER

Examples of images produced by using advanced imaging techniques together with

cartographic tools to study a given area

A digital orthophoto is a digital image of an 

aerial photograph with the distortion removed.

45
46

Population

The water resources and population of an area

are intricately interconnected. An ample supply of

good-quality water provides water for drinking, irrigation, industrial use, and possibly recreation. These 

factors tend to draw people to an area. As the population grows, land is developed, decreasing the pervious surface area through which infiltration can 

occur to recharge the aquifers; growing industries 

and agriculture may discharge contaminants to

streams and aquifers; and the drinking-water supply 

must serve more people. 

The growth of New Jersey’s population from

1880 to 1990 is shown in figure 16a. Since 1970, 

New Jersey has had the highest population density in

the United States (N.J. Department of Labor, 1991). 

The population more than quadrupled from 1890 to

1990, and increased approximately 27 percent from 

1960 to 1990. Along with the population increase 

has come a need for larger, more efficient publicwater supply systems, additional reservoirs to store 

water, and more wells in deeper aquifers. 

The population of each of the five water 

regions and population trends for 2010 and 2040, as

projected in the New Jersey Statewide Water Supply 

Plan (N.J. Department of Environmental Protection,

1996c), are shown in figure 16b. The Northeast

water region has the smallest land area but the highest population density. This water region is in the 

most urban and industrialized part of the State (fig.

15). Roughly 35 percent of New Jersey’s population 

lives within this water region. For comparison, the

Atlantic Coastal and Lower Delaware water regions, 

which together have a land area four times that of the

Northeast water region, also is home to about 35 percent of the State’s population. 

The Raritan and Lower Delaware water

regions also have large urban centers (fig. 15), but 

their population densities are smaller than that of the

Northeast water region. The Atlantic Coastal and 

Northwest water regions have the smallest population densities.

The population of the Northeast water region

is predicted to decrease slightly by 2040 (fig. 16b) 

because of a move from urban to suburban areas. The

populations of all the other water regions are projected to increase by 2040.

Heavily populated residential area in the 

northern Coastal Plain, New Jersey. (File 

photograph, U.S. Geological Survey, West

Trenton, New Jersey)
47

Northwest Lower Delaware Raritan Northeast Atlantic Coastal

WATER REGION

3,000

0

500

1,000

1,500

2,000

2,500

POPULATION, 

IN PEOPLE PER SQUARE MILE

1990

2010

2040

Figure 16. (a) Population density in New Jersey from 

1880 to 1990 (data from N.J. Department of Labor, 

1991) and (b) population densities of the five water 

regions in New Jersey in 1990, and projected densities 

for 2010 and 2040 (N.J. Department of Environmental 

Protection, 1996c). As of 1990, the population of New 

Jersey had quadrupled since 1890 and grown 30 

percent since 1960. The demands on the water 

resources are great. Of the five water regions, the 

Northeast water region has the smallest land area but 

the greatest population density. Thirty-five percent of 

the State s population lives in this water region. In 

contrast, the population of the Atlantic Coastal and 

Lower Delaware water regions combined make up 

35 percent of the State s population. The populations 

of all water regions except the Northeast are predicted 

to increase still further by 2010 and 2040.

1880 1900 1920 1940 1960 1980 1990

YEAR

0

1,200

0

200

400

600

800

1,000

POPULATION, 

IN PEOPLE PER SQUARE MILE

a.

b.

1890 1910 1930 1950 1970
48

Surface-Water Data

Streams

The USGS operates a network of sites

throughout the State where streamflow is measured. 

These data are crucial to regulatory agencies, watershed-management groups, and scientific communities for planning purposes and water-resource

studies. Streamflow-gaging stations provide the 

most complete information, but some streamflow

data are collected by other means.

The locations of all the surface-water data-collection sites in New Jersey are shown in figures 17 

and 18. Types of data-collection stations are streamflow-gaging stations, discontinued streamflow-gaging stations, crest-stage partial-record stations, lowflow partial-record stations, and tide-gaging stations. 

At each of these sites, measurements are made at different intervals and for different purposes.

In any given year, about 90 to 100 USGS 

streamflow-gaging stations are in operation in New 

Jersey. At these sites, water levels are recorded continuously (every 15 minutes). USGS personnel typically visit these sites once every 6 to 8 weeks to

measure discharge (flow rate) to determine the relation between the stage of the stream (the height of the 

water surface above an established level) and its 

flow. This information is published by the USGS

annually in the water-resources data report (for 

example, Reed and others, 1998). Real-time data for 

Flatbrook at Flatbrookville, New Jersey, has been

gaged since July 1923. (Photograph by Gretchen

Wall)

selected sites also are available; these data are posted

on the USGS homepage on the Internet (see address 

in List of Contacts, at end of report). These data are

important when up-to-the-minute information on 

stream stage is needed at frequent intervals for flood 

forecasting, reservoir operations, and flow prediction. Long-term streamflow data also are important

for assessing changes that result from human activities (agricultural practices, urbanization, and 

ground-water development) or climatic changes 

(Wahl and others, 1995). The locations of the discontinued streamflow-gaging stations in the State are 

shown in figure 17. Although measurements are no 

longer made, the USGS maintains historical streamflow records for these sites. 

WATER-RESOURCE DATA
49

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

Watershed Management 

Area boundary--From N.J. 

Department of Environmental 

Protection, 1:24,000 digital 

line graph file, 1997

Active streamflow-gaging station

Discontinued streamflow-gaging

station

Head of tide of major rivers--

Locations from digital data, N.J. 

Department of Environmental 

Protection, 1998

EXPLANATION

Figure 17. Streamflow-gaging stations active in New Jersey in water year 1997. At these stations, 

stream stage is measured continuously. This information is used for flood-forecasting, reservoir 

operation, and predicting flow. At discontinued stations, data are no longer collected, but historical

records are maintained by the U.S. Geological Survey. (Head of tide is the point on a stream at 

which the effects of the tide are no longer observed.)
50

Crest-stage gages are established to measure 

only the highest water level that occurred between 

visits by USGS personnel. The “bracketing” visit 

dates, rather than a specific time, are associated with 

this measurement. These gages are simple, economical, reliable, and easy to install. The highest water 

level is important to engineers who design highways, 

culverts, and bridges, and to agenciesresponsible for 

the safety and well-being of people in the event of a 

flood. Between 50 and 100 crest-stage gages are

located throughout the State (fig. 18).

Low-flow partial-record sites perform the

opposite function of the crest-stage-gage sites. They

are located on many streams throughout the State 

(fig. 18). These sites are established to measure flow 

during conditions that are presumed to represent 

base-flow conditions, defined as 3 days with no rain 

for the northern part of the State and 5 days with no 

rain for the southern part of the State. (The criterion

differs between the northern and the southern parts 

of the State because of the difference in the storage 

capacity of the sediments.) No recording devices are 

installed at these stations; USGS personnel typically

visit them twice each year to make discharge measurements. Data collected at low-flow partial-record

stations provide an estimate of the base flow, or sustained or fair-weather flow, of the stream. This information is important for setting minimum passing 

flows, or limiting the discharge from a wastewatertreatment plant to a stream in order to protect the

habitat of the fish, plants, and other wildlife. 

The USGS has established several different

networks to measure the tides in New Jersey’s 

coastal areas (fig. 18). At tide-gaging stations, the 

height of tides is measured on a continuous basis. 

The maximum high tide, minimum low tide, and 

associated dates, as well as mean high and low tides,

are published by the USGS annually in the waterdata reports. Tidal crest-stage gages are set up and 

operate like stream crest-stage gages but are located

in stream reaches that are affected by the tides. The 

largest network that measures the tides is the New 

Jersey Tide Telemetry System operated by the 

USGS, which consists of tide gages, tidal-crest-stage

gages, weather sensors, and computer base stations. 

The network stretches from Newark to Cape May 

and includes the Delaware Bay and Delaware River.

It was established to help minimize the extensive 

damage that can result from flooding in New Jersey’s 

coastal regions and back bays. Also, as the populations of the coastal regions increase, large storms 

threaten developed areas and timely evacuation of

residents is crucial. The telemetry system (electronic 

equipment that transmits measurementsto a base station) that is connected to these gages transmits measurements of tide levels, air and water temperature,

rainfall, wind speed and direction, and barometric

pressure directly to the National Weather Service,

New Jersey State Police, New Jersey Department of

Transportation, and county emergency management

agencies (the base stations). This information is crucial for flood forecasting, determining evacuation 

routes, and designing roads and bridges (see Summer, 1998a) (fig. 19).

Tide-telemetry (left) and weather-monitoring

equipment at Cape May Harbor at U.S. Coast

Guard Training Center, Cape May, New Jersey.

(Photograph by John Stepnowski, National 

Ocean Service)
51

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

Watershed Management 

Area boundary--From N.J. 

Department of Environmental 

Protection, 1:24,000 digital 

line graph file, 1997

Low-flow partial-record station

Crest-stage partial-record station

Tide-gaging station

Low-flow partial-record and

crest-stage partial-record station

Tide crest-stage partial-record

station

EXPLANATION

Figure 18. Low-flow partial-record stations, crest-stage partial-record stations, and tide-gaging 

stations active in New Jersey in water year 1997. Streamflow is measured at low-flow partialrecord stations under base-flow conditions. Crest-stage partial-record stations record the 

highest flow during a specific period. Tide gages measure the highs and lows of the tide.
52

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

SUSSEX

MORRIS

BERGEN

ESSEX HUDSON

UNION

MIDDLESEX

MONMOUTH MERCER

HUNTERDON SOMERSET

WARREN

OCEAN

BURLINGTON

ATLANTIC

CAMDEN

GLOUCESTER

SALEM

CUMBERLAND

CAPE

MAY

PASSAIC

Figure 19. Tide-telemetry stations, flood-warning systems, and weather stations active in 

New Jersey in 1999. Information from the tide-telemetry network is used to help protect 

coastal areas from flooding. The flood-warning systems are located in the most densely 

populated part of the State to help protect life and property. The information collected by 

these networks is used for flood-forecasting, determining evacuation routes, and designing

roads and bridges.

EXPLANATION

Stage only

Gaging and precipitation station

Stage only

Tide-telemetry and precipitation station

Tide telemetry and full weather station

Flood-warning system gaging station--

Precipitation station

Tide-telemetry station--

Boundary of Northeast 

Water Region in New York
53

Selected data collected at the continuous

streamflow-gaging stations in operation in water 

year1 1997 in the State are listed in table 4. Information such as drainage area (size of watershed), period 

of record (how long the gage has been operating), 

and the highest annual mean, the lowest annual 

mean, and the mean annual discharge through 1997 

at the gage are shown. Mean annual discharge in

cubic feet per second per square mile and mean 

annual discharge in inches over the drainage basin 

also are included. These values allow planners and 

researchers to compare the hydrologic characteristics of watersheds regardless of differences in their

size. Mean annual discharge in cubic feet per second 

per square mile is the average number of cubic feet 

of water flowing per second from each square mile

of area drained, if runoff is assumed to be distributed 

uniformly in time and area (Reed and others, 1998). 

Mean annual discharge in inches over the drainage 

basin--the depth to which the drainage area would be

covered if all the discharge for a given period of time 

were uniformly distributed over it--is a useful statistic because it can be compared to precipitation. The 

long-term statewide mean annual precipitation is

44.67 inches (1897-1997) (National Oceanic and 

Atmospheric Administration, 1997). The discharge 

in inches over the drainage basin can be thought of 

as the amount of precipitation that is left after evapotranspiration, recharge to deeper aquifers, and 

ground-water and surface-water withdrawals.

When mean annual discharge at a gaging station, expressed in cubic feet per second per square

mile, and mean annual discharge, expressed in 

inches over the drainage basin, are unusually or

unexpectedly high or low in comparison to the same 

statistic for nearby drainage basins, it is likely that

either natural hydrologic conditions or man-made 

conditions has affected the discharge at the station, 

or that the period of record at the station is very short.

For example, discharge at the Mullica River near

Batsto, N.J., streamflow-gaging station is higher

than expected because this drainage basin receives 

inflow from Sleeper Branch, a tributary drainage

basin. In contrast, the Oswego River at Harrisville, 

N.J., loses water to a neighboring drainage basin and, 

therefore, has a lower than expected discharge. Manmade conditions such as streamflow diversions for 

municipal supply or filling reservoirs, releases from

reservoirs to maintain minimum passing flow, and 

ground-water withdrawals adjacent to streams all

result in lower than normal discharge. Controlled 

releases from upstream reservoirs reduce discharge

at the Wanaque River at Wanaque, N.J., and Hackensack River at New Milford, N.J., streamflow-gaging

stations. Other stations, such as South Branch Rockaway River at Whitehouse Station, N.J., may measure the release of water from a reservoir into the

stream above the station and thus have higher than 

normal discharge. Flow statistics for stations with

less than 20 years of record may not accurately represent long-term flow characteristics. Flow statistics

for the streamflow-gaging station on the Whippany 

River near Morristown, N.J., is higher than expected, 

a consequence of the short period of record at the station. This stream has been gaged only since August 

1995 and because 1996 was a wetter than normal 

year, mean annual discharge computed for this station is considered to be higher than normal.

Low water at Pequannock River at Macopin 

intake dam, New Jersey. (File photograph, U.S. 

Geological Survey, West Trenton, New Jersey)

1

A water year is the 12-month period beginning on October 1 and ending on September 30. The water year is

designated by the calendar year in which it ends.
5

4

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 

WATER MANAGEMENT AREA 1 - UPPER DELAWARE RIVER

Delaware River at Montague,N.J. 01438500

PikeCounty, Pa.

3,480 Mar. 1936-Sept.

1939, Oct. 1939-Sept. 1997

5,717 8,621 (1952) 2,309 (1965) 1.64 22.31 Di

upwa

Flat Brook near Flatbrookville,N.J. 01440000

Sussex 64.0 July 1923-Sept.

1997

111 210 (1928) 43.4 (1965) 1.74 23.58 Di

up

East Branch Paulins Kill nearLafayette, N.J. 01443280

Sussex 13.0 Aug. 1992-Sept.

1997

23.4 27.2 (1996) 15.6 (1995) 1.80 24.48 Po

upfloqu

Paulins Kill at Blairstown, N.J.01443500

Warren 126 Oct. 1921-Sept.

1976, Oct. 1977-Sept. 1997

198 362 (1952) 67.4 (1965) 1.57 21.39 Di

La

Yards Creek near Blairstown,N.J. 01443900 

Warren 5.34 Oct. 1966-Sept.

1997

11.0 16.1 (1996) 3.17 (1985) 2.06 27.97 Di

vo

Pequest River at Pequest, N.J.01445500

Warren 106 Oct. 1921-Sept.

1997

158 285 (1952) 45.8 (1965) 1.49 20.25 Di

un

Delaware River at Belvidere,N.J. 01446500

Warren 4,535 Oct. 1922-Sept.

1997

7,854 14,130 (1928) 2,990 (1965) 1.73 23.52 Di

voCi

Musconetcong River nearBloomsbury, N.J. 01457000

Warren 141 July 1903-Mar.

1907, July 1921-Sept. 1997

240 425 (1928) 82.6 (1965) 1.70 23.11 Di

WATER MANAGEMENT AREA 3 - POMPTON, PEQUANNOCK, WANAQUE, AND RAMAPO RIVERS

Pequannock River at Riverdale,N.J. 01382800 

Passaic 83.9 Oct. 1993-Sept.

1997

116 150 (1996) 50.2 (1995) 1.38 18.77 Di

istReark 

Wanaque River at Awosting,N.J. 01383500

Passaic 27.1 May 1919-Sept.

1997

54.5 105 (1984) 19.9 (1965) 2.01 27.31 Di

woDimu

Ringwood Creek nearWanaque, N.J. 01384500

Passaic 19.1 Oct. 1934-Sept.

1978, Oct. 1985-Sept. 1997

33.4 54.4 (1952) 13.2 (1965) 1.75 23.75 Di

up

1 Although station 01438500, Delaware River at Montague, N.J., is located in Pennsylvania, it is operated by the U.S. Geological Survey in West Trenton, N.J.
55

WATER MANAGEMENT AREA 3 - POMPTON, PEQUANNOCK, WANAQUE, AND RAMAPO RIVERS--Continued

Wanaque River at Wanaque,N.J. 01387000 

Passaic 90.4 Dec. 1903-Dec.

1905, Sept. 1912-April 1915, May1919-Sept. 1997

73.7 231 (1920) 1.93 (1966) .82 11.07 Di

Mdivply 

Ramapo River near Mahwah,N.J. 01387500 

Bergen 120 Oct. 1902-Dec.

1906, Sept. 1922-Sept. 1997

230 461 (1903) 99.5 (1985) 1.91 25.99 Di

sioup

Ramapo River at Pompton Lakes, N.J. 01388000 

Passaic 160 Oct. 1921-Sept.

1997

287 512 (1984) 73.1 (1985) 1.79 24.36 Sli

LaRianEcDiUnply

Pompton River at PomptonPlains, N.J. 01388500 

Passaic 355 Mar. 1903-Dec.

1904, May 1940-Sept. 1997

490 906 (1952) 117 (1965) 1.38 18.74 Di

RianEcsio

WATER MANAGEMENT AREA 4 - LOWER PASSAIC AND SADDLE RIVERS

Passaic River at Little Falls, N.J. 01389500

Passaic 762 Sept. 1897-Sept.

1997

1,146 2,394 (1903) 269 (1965) 1.50 20.42 Di

paup

Saddle River at Ridgewood,N.J. 01390500 

Bergen 21.6 Oct. 1954-Sept.

1974, Oct. 1977-

34.4 58.7 (1984) 14.7 (1995) 1.59 21.61 Di

dra

Saddle River at Lodi, N.J.01391500

Bergen 54.6 Sept. 1923-Sept.

1997

100 187 (1984) 45.2 (1981) 1.83 24.87 Di

sio

Third River at Passaic, N.J.01392210

Passaic 11.8 May 1977-Sept.

1997

21 32.7 (1978) 12.7 (1995) 1.78 24.14 Di

po

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
56

WATER MANAGEMENT AREA 5 - HACKENSACK RIVER AND PASCACK BROOK

Hackensack River at Rivervale, N.J. 01377000 Bergen 58 Oct. 1941-Sept. 1997 88.2 156 (1952) 30.9 (1981) 1.52 20.65 Di

lat

Pascack Brook at Westwood,N.J. 01377500

Bergen 29.6 Oct. 1934-Sept.

1997

54.3 88.6 (1952) 27.6 (1965) 1.83 24.91 Di

Mbly 

Hackensack River at NewMilford, N.J. 01378500

Bergen 113 Oct. 1921-Sept.

1997

94.1 263 (1928) .40 (1981) .83 11.31 Di

latcli

WATER MANAGEMENT AREA 6 - UPPER PASSAIC, WHIPPANY, AND ROCKAWAY RIVERS

Passaic River near Millington,N.J. 01379000

Somerset 55.4 Nov. 1903-June

1906, Oct. 1921-Sept. 1997

91.7 163 (1984) 32.3 (1965) 1.65 22.48

Passaic River near Chatham,N.J. 01379500

Morris 100 Feb. 1903-Dec.

1911, Oct. 1937-Sept. 1997

173 305 (1984) 67.7 (1965) 1.75 23.52

Green Pond Brook at Picatinny Arsenal, N.J. 01379773

Morris 7.65 Oct. 1982-Sept.

1997

14.0 21.4 (1984) 6.63 (1985) 1.82 24.79 Di

De

Green Pond Brook below Picatinny Lake, at Picatinny Arsenal, N.J. 01379780 Morris 9.16 Oct. 1984-Sept. 1997 15.2 22.1 (1990) 6.35 (1985) 1.66 22.50 Di

tin

Green Pond Brook at Wharton,N.J. 01379790

Morris 12.6 Oct. 1982-Sept.

1997

25.4 40.7 (1984) 12.5 (1985) 2.01 27.35 Di

Pictre

Rockaway River above Reservoir, at Boonton, N.J. 01380500 Morris 116 Oct. 1937-Sept. 1997 231 396 (1952) 88.3 (1965) 1.99 27.04 DiRockaway River below Reservoir, at Boonton, N.J. 01381000 Morris 119 Mar.-Dec. 1903, Jan., Feb. 1904,

Jan. 1906-Sept.1950, Oct. 1950-Sept. 1997

141 296 (1952) 7.19 (1965) 1.18 16.09 Di

Spsey 

Whippany River near Morristown, N.J. 01381400 Morris 14.0 Aug. 1995-Sept. 1997 43.8 50.9 (1997) 36.9 (1996) 3.13 42.56 W

mu

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
57

WATER MANAGEMENT AREA 6 - UPPER PASSAIC, WHIPPANY, AND ROCKAWAY RIVERS--Continued

Whippany River at Morristown,N.J. 01381500 

Morris 29.4 Aug. 1921-Sept.

1997

54.5 98.5 (1984) 23.3 (1965) 1.85 25.20 Di

tio

Passaic River at Pine Brook,N.J. 01381900

Morris 349 Oct. 1979-Sept.

1997

640 1,125 (1984) 276 (1981) 1.84 24.90 Di

SpWwa

Pequannock River at Macopinintake dam, N.J. 01382500

Morris 63.7 Jan. 1898-Mar.

1990, Sept. 1992-Sept. 1997

47.1 109 (1952) .12 (1954) .74 10.04 Di

RianNe

WATER MANAGEMENT AREA 7 - ELIZABETH, RAHWAY, AND WOODBRIDGE RIVERS

Elizabeth River at Ursino Lake,at Elizabeth, N.J. 01393450

Union 16.9 Oct. 1921-Sept.

1997

25.9 48.3 (1971) 10.2 (1923) 1.54 20.81 Di

dra

Rahway River near Springfield,N.J. 01394500 

Union 25.5 July 1938-Sept.

1997

30.0 55.9 (1973) 10 (1965) 1.18 15.98 Di

dra

Rahway River at Rahway, N.J.01395000

Union 40.9 July 1908-April

1915, Oct. 1921-Sept. 1997

48.7 105 (1973) 15 (1965) 1.19 16.17 Di

dra

WATER MANAGEMENT AREA 8 - NORTH AND SOUTH BRANCH RARITAN RIVERS

South Branch Raritan River near High Bridge, N.J.01396500 

Hunterdon 65.3 Oct. 1918-Sept.

1997

124 213 (1928) 46.2 (1965) 1.89 25.71 Di

fro

Spruce Run at Glen Gardner,N.J. 01396580

Hunterdon 11.3 Mar. 1978-Sept.

1988, Dec. 1991-Sept. 1997

21.5 33.3 (1984) 11.3 (1995) 1.90 25.84 Di

fro

Mulhockaway Creek at Van Syckel, N.J. 01396660

Hunterdon 11.8 July 1977-Sept.

1997

20.5 35.2 (1984) 11.1 (1992) 1.74 23.60

Spruce Run at Clinton, N.J.01396800 

Hunterdon 41.3 May 1959-Sept.

1997

66.3 111 (1997) 3.81 (1964) 1.61 21.80 Di

vo

South Branch Raritan River atStanton, N.J. 01397000

Hunterdon 147 July 1903-Dec.

1906, July 1919-Sept. 1997

249 413 (1952) 95.0 (1966) 1.69 23.00 Di

lat

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
58

WATER MANAGEMENT AREA 8 - NORTH AND SOUTH BRANCH RARITAN RIVERS--Continued

Neshanic River at Reaville, N.J. 01398000

Hunterdon 25.7 June 1930-Sept.

1997

37.9 70.8 (1994) 14.5 (1965) 1.47 20.04

North Branch Raritan Rivernear Far Hills, N.J. 01398500

Somerset 26.2 Oct. 1921-Sept.

1975, Oct. 1977-Sept. 1997

48.6 89.7 (1928) 17.7 (1965) 1.85 25.19

Lamington (Black) River nearPottersville, N.J. 01399500

Morris 32.8 Oct. 1921-Sept.

1997

56.3 104 (1928) 20.5 (1965) 1.72 23.32

Upper Cold Brook near Pottersville, N.J. 01399510 Hunterdon 2.18 Oct. 1972-Sept. 1996 3.91 7.07 (1984) 1.75 (1985) 1.79 24.37South Branch Rockaway Creekat Whitehouse Station, N.J.01399670 

Hunterdon 12.3 Oct. 1986-Sept.

1997

28.1 55.2 (1981) 11.1 (1992) 2.28 31.02 Di

Vaga

North Branch Raritan Rivernear Raritan, N.J. 01400000 

Somerset 190 July 1923-Sept.

1997

312 605 (1984) 120 (1965) 1.64 22.30 Di

Vaga

WATER MANAGEMENT AREA 9 - LOWER RARITAN RIVER, SOUTH RIVER, AND LAWRENCE BROOK

Raritan River at Manville, N.J.01400500

Somerset 490 June 1903-Mar.

1907, Aug. 1908-April 1915, Aug.1921-Sept. 1997

779 1,365 (1984) 309 (1965) 1.59 21.59 Di

lat

Raritan River below CalcoDam at Bound Brook, N.J.01403060

Somerset 785 Sept. 1903-Mar. 

1909, Oct. 1944-Sept. 1997

1,208 2,046 (1975) 480 (1985) 1.54 20.90 Di

paRo

West Branch Middle Brooknear Martinsville, N.J.01403150

Somerset 1.99 June 1979-Sept.

1997

3.74 5.48 (1989) 1.88 (1981) 1.88 25.51

Green Brook at Seeley Mills,N.J. 01403400

Somerset 6.23 June 1979-Sept.

1997

10.6 18.2 (1984) 5.16 (1981) 1.71 23.19

East Branch Stony Brook atBest Lake, at Watchung, N.J.01403535

Somerset 1.57 July 1980-Sept.

1997

2.71 4.47 (1984) 1.48 (1981) 1.73 23.44

Stony Brook at Watchung, N.J.01403540

Somerset 5.51 Oct. 1974-Sept.

1997

10.2 16.0 (1984) 5.43 (1995) 1.85 25.17

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
59

WATER MANAGEMENT AREA 9 - LOWER RARITAN RIVER, SOUTH RIVER, AND LAWRENCE BROOK--Continued

Bound Brook at Middlesex,N.J. 01403900

Somerset 48.4 Oct. 1972-Oct.

1977, April 1996-Sept. 1997

79.3 112 (1973) 40.3 (1977) 1.63 22.25

Lawrence Brook at WestonMills, N.J. 01405030

Middlesex 44.9 Dec. 1988-Oct.

1994, July 1995-Sept. 1997

53.6 68.7 (1993) 30.6 (1995) 1.19 16.21 Dis

affeWa

Manalapan Brook atSpotswood, N.J. 01405400

Middlesex 40.7 Jan. 1957-Sept.

1997

63.1 101 (1973) 34.3 (1981) 1.55 21.05 Dis

LakLak

WATER MANAGEMENT AREA 10 - MILLSTONE RIVER

Stony Brook at Princeton, N.J.01401000

Mercer 44.5 Oct. 1953-Sept.

1997

66.7 118 (1996) 28.5 (1966) 1.50 20.36 Dis

voi

Pike Run at Belle Mead, N.J.01401650

Somerset 5.36 July 1980-Sept.

1997

9.07 14.3 (1984) 3.79 (1981) 1.69 22.99

Millstone River at BlackwellsMills, N.J. 01402000

Somerset 258 June 1903-Dec.

1904, Aug. 1921-Sept. 1997

383 690 (1975) 165 (1985) 1.48 20.17 Dis

Lakaffewa

WATER MANAGEMENT AREA 11 - CENTRAL DELAWARE TRIBUTARIES

Delaware and Raritan Canal atPort Mercer, N.J. 01460440

Mercer -- Aug. 1990-Sept.

1997

134 143 (1991) 120 (1992) -- -- Dis

Demu

Delaware River at Trenton, N.J.01463500

Mercer 6,780 Feb. 1913-Sept.

1997

11,700 19,810 (1928) 4,708 (1965) 1.72 23.43 Dis

late

Assunpink Creek at Trenton,N.J. 01464000

Mercer 90.6 Aug 1923-Sept.

1997

133 233 (1984) 69.2 (1931) 1.47 19.94 Dis

voi

WATER MANAGEMENT AREA 12 - MONMOUTH WATERSHEDS

Swimming River near Red Bank, N.J. 01407500

Monmouth 49.2 Aug. 1922-Sept.

1997

81.0* 123 (1928) 9.76 (1985) 1.28 17.41 Dis

Reply

Shark River near Neptune City,N.J. 01407705

Monmouth 9.96 Oct. 1966-Sept.

1997

14.3 24.9 (1984) 6.80 (1995) 1.44 19.50 Dis

for 

Jumping Brook near NeptuneCity, N.J. 01407760

Monmouth 6.46 Oct. 1966-Sept.

1997

9.91 20.4 (1979) 4.05 (1981) 1.53 20.83 Dis

for 

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
60

WATER MANAGEMENT AREA 12 - MONMOUTH WATERSHEDS--Continued

Manasquan River at Squankum,N.J. 01408000

Monmouth 44.0 July 1931-

Sept. 1997

74.4 131 (1978) 40.2 (1995) 1.69 22.99

Manasquan River near Allenwood, N.J. 01408029 Monmouth 63.3 June 1990- Sept. 1997 81.2 103 (1997) 39.4 (1995) 1.28 17.42 Di

pa

WATER MANAGEMENT AREA 13 - BARNEGAT BAY WATERSHEDS

North Branch MetedeconkRiver near Lakewood, N.J.01408120

Ocean 34.9 Oct. 1972-Sept.

1997

60.5 91.5 (1984) 34.7 (1981) 1.73 23.54

South Branch MetedeconkRiver near Lakewood, N.J.01408150

Ocean 27.5 June 1992-

Sept. 1997

56.3 65.8 (1997) 36.4 (1995) 2.05 27.80 Di

Ca

Toms River near Toms River,N.J. 01408500

Ocean 123 Oct. 1928-Sept.

1997

212 335 (1978) 128 (1995) 1.72 23.41 Di

fro

WATER MANAGEMENT AREA 14 - MULLICA AND WADING RIVERS

Mullica River near Batsto, N.J.01409400

Atlantic 46.7 Sept. 1957-Sept.

1997

107 168 (1973) 50.4 (1966) 2.29 31.11 Di

craSlech

Batsto River at Batsto, N.J. 01409500

Burlington 67.8 Oct. 1927-Sept.

1997

122 193 (1958) 66.2 (1966) 1.80 24.46 Di

Oswego River at Harrisville,N.J.

Burlington 72.5 Oct. 1930-Sept.

1997

86.5 138 (1978) 41.4 (1966) 1.19 16.21 Di

pochousu

East Branch Bass River nearNew Gretna, N.J. 01410150

Burlington 8.11 Jan. 1978-Sept.

1997

15.8 23.2 (1997) 9.60 (1985) 1.95 26.54 Di

La

WATER MANAGEMENT AREA 15 - GREAT EGG HARBOR AND TUCKAHOE RIVERS

Great Egg Harbor River nearSicklerville, N.J. 01410784

Camden 15.1 Mar. 1996-Sept.

1997

20.6 20.6 (1997) 20.6 (1997) 1.36 18.51

Great Egg Harbor River nearFolsom, N.J. 01411000 

Atlantic 57.1 September 1925-

Sept. 1997

86.1 133 (1973) 44.4 (1931) 1.51 20.48

Tuckahoe River at Head of River, N.J. 01411300

Cape May 30.8 December 1969-

Sept. 1997

43.2 64.3 (1984) 21.7 (1995) 1.40 19.04 Di

fro

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
61

WATER MANAGEMENT AREA 17 - MAURICE, SALEM, AND COHANSEY RIVERS

Little Ease Run near Clayton,N.J. 01411456

Gloucester 9.77 Feb 1988-Sept.

1997

11.2 14.3 (1997) 5.7 (1995) 1.14 15.55 Di

fro

Maurice River at Norma, N.J.01411500

Salem 112 July 1932-Sept.

1997

165 253 (1973) 67.4 (1966) 1.47 19.97 Di

fro

WATER MANAGEMENT AREA 18 - LOWER DELAWARE TRIBUTARIES

Raccoon Creek near Swedesboro, N.J. 01477120 Gloucester 26.9 May 1966-Sept. 1997 40.6 64.7 (1973) 22.5 (1981) 1.51 20.50

WATER MANAGEMENT AREA 19 - RANCOCAS CREEK

McDonald Branch in Lebanon State Forest, N.J. 01466500

Burlington 2.35 Oct. 1953-Sept.

1997

2.18 3.85 (1973) 1.17 (1995) .93 12.62 Hy

affaq

North Branch Rancocas Creekat Pemberton, N.J. 01467000

Burlington 118 Sept. 1921-Sept.

1997

171 286 (1978) 92.3 (1995) 1.45 19.69 Di

latbo

South Branch PennsaukenCreek at Cherry Hill, N.J.01467081

Camden 8.98 Oct. 1967-Sept.

1976, Oct. 1977-Sept. 1997

18.9 27.3 (1978) 11.6 (1995) 2.10 28.56

Cooper River at Haddonfield,N.J. 01467150

Camden 17.0 Oct. 1963-Sept.

1997

34.2 50.6 (1973) 19.2 (1995) 2.01 27.34 Di

frowa

WATER MANAGEMENT AREA 20 - CROSSWICKS CREEK

Crosswicks Creek at Extonville, N.J. 01464500 Mercer 81.5 Aug. 1940-Oct. 1951, Oct. 1952-

Sept. 1997

135 225 (1978) 69.9 (1995) 1.66 22.51 Di

up

Table 4. Selected information for continuous streamflow-gaging stations in New Jersey1 through water year 1997--Continued

Discharge, for period of record analyzed

U.S. Geological Survey

streamflow-gaging station

name and number County

Drainage area

(square

miles)

Period of

record analyzed

Mean

annual

(cubic feet

per second)

Highest annual

mean (cubic feet

per second; year

in parentheses)

Lowest annual

mean (cubic feet

per second; year

in parentheses)

Mean

annual

(cubic feet

per second

per square

mile)

Mean

annual

(inches per 

year over 

drainage

area) 
62

Daily discharge at the streamflow-gaging station on the Toms River near Toms River, N.J., and 

monthly precipitation at the Toms River weather station for a 2-year period (1995-96) are shown in figure 20. These 2 years were very different from each 

other--1995 was an extremely dry year with many

water restrictions, and 1996 was one of the wettest

years in recorded history. The long-term mean 

annual precipitation at the Toms River weather station is 47.14 inches and the long-term statewide 

mean annual precipitation is 44.67 inches (1897-

1997) (National Oceanic and Atmospheric Administration, 1997). In 1995, the precipitation at the Toms 

River weather station totalled 38.27 inches, which is

85 percent of the long-term average at that station.

Rainfall exceeded the monthly average in only 3 

months that year--May, October, and November. The

discharge at the streamflow-gaging station on the 

Toms River near Toms River, N.J., reflects the 

below-normal precipitation. Discharge for water

year 1995 was 128 ft3/s (cubic feet per second), compared to the long-term average of 212 ft

3

/s for water 

years 1929-96 (table 4). Monthly mean discharges 

were below long-term averages for the entire year.

Discharge decreased in response to the lack of rain

from late winter through summer, reaching a low in 

mid-September. The increased precipitation in the 

fall (October and November) caused the discharge to 

increase (fig. 20). The monthly precipitation for 

November totalled 8.92 inches, almost 5 inches

above normal, causing a peak discharge for the year

of 701 ft3/s.

In contrast, 1996 was one of the wettest years

on record. The Blizzard of ‘96 in early January left

more than 2 ft of snow in most of the State, and the 

melting of this snow caused widespread flooding

(Reed and others, 1997). Precipitation in the Toms

River Basin was higher than normal for 8 months of

the year, which made flows in the Toms River higher 

than normal for the whole year. The annual mean discharge at the streamflow-gaging station on the Toms

River near Toms River, N.J., in 1996 was 229 ft3/s,

which is 108 percent of long-term mean annual discharge (Reed and others, 1997). Discharge was

greater than normal from June through the end of the

year and peaked in mid-October with a discharge of 

770 ft

3/s from a storm on October 19-20 (Reed and 

others, 1997).

J F M A M J J A S O N D J F M A M J J A S O N D

1995 1996

40

1,000

50

60

70

80

90

100

150

200

250

300

400

500

600

700

800

900

DISCHARGE, IN CUBIC FEET PER SECOND

1

10

2

3

4

5

6

7

8

9

PRECIPITATION, IN INCHES

Precipitation at Toms River, N.J., 

weather station (From 

National Oceanic and 

Atmospheric Administration, 

1995-96)

Discharge at Toms River 

near Toms River, N.J., 

streamflow-gaging station 

Figure 20. Relation of daily mean discharge at the 

Toms River near Toms River, N.J., streamflow-gaging 

station to monthly precipitation at the Toms River, N.J., 

weather station. Streamflow and precipitation are 

closely related. Because 1995 was an extremely dry 

year, stream discharge declined to less than 50 cubic 

feet per second by September. Higher precipitation 

amounts in October and November, however, caused 

discharge to increase to nearly 700 cubic feet per

second in November. 1996, in contrast, was one of 

the wettest years on record. The blizzard of January 

1996 and the accompanying snowmelt caused discharge to approach 800 cubic feet per second. Many 

months of record rainfall maintained streamflow at 

high levels throughout the year. 

0 30
63

Flow-duration curves

The flow of water past a point on a stream is

measured at a streamflow-gaging station. Streamflow records integrate the effects of climate, topography, and geology, and show the distribution and

magnitude of runoff in time. Streamflow characteristics of a gaging station can be summarized by constructing a flow-duration curve, which is a graph that

shows the percentage of time a given flow at a given 

point on a stream is either equalled or exceeded

(Searcy, 1959). Flow-duration curves can be constructed from either daily or annual discharge measurements. If the curves are constructed by using 

units of cubic feet per second per square mile of

drainage area, the characteristics of watersheds of 

different sizes can be compared. The shape of a flowduration curve reveals important information about 

the hydrologic and geologic characteristics of a 

basin. Steeply sloping flow-duration curves indicate

streams with highly variable flow derived mostly

from overland runoff; more gently sloping flowduration curves indicate streams with more constant

flow derived mostly from ground-water storage.

Four flow-duration curves, each from a stream 

in a different physiographic province in New Jersey, 

are shown in figure 21. The slope of the flow-duration curve for Stony Brook at Princeton, N.J., in the 

Piedmont Physiographic Province is steep, indicating highly variable flow. The Piedmont Physiographic Province is rocky, with thin soils and little

ground-water storage capacity, and most precipitation runs off to streams. Therefore, streamflow is

composed mainly of overland runoff with little

ground-water discharge. Because streamflow 

depends mainly on precipitation rather than the 

steady contribution of ground water, it tends to be

highly variable. The flow-duration curve for the 

Great Egg Harbor River at Folsom, N.J., in the 

Coastal Plain Physiographic Province is relatively

flat, indicating significant ground-water storage in

thick deposits of sand and in wetlands. The Coastal 

Plain Physiographic Province is sandy; therefore, little water runs overland to streams and most infiltrates into the ground and recharges the aquifer,

which leads to a steady ground-water contribution to

streams and thus stable streamflow (Fetter, 1980). 

The slopes of the flow-duration curves for Flat

Brook near Flatbrookville, N.J., in the Valley and

Ridge Physiographic Province, and South Branch

Raritan River near High Bridge, N.J., in the New

England Physiographic Province, are intermediate

between the slopes of the curves for Stony Brook and 

Great Egg Harbor River, indicating that streamflow 

consists of a more even balance of ground-water discharge stored in sedimentary rocks and glacial

deposits and overland runoff derived from precipitation. 

The information provided by flow-duration 

curves is important to planners and developers. It can

be used for predicting floods; to locate industries; for 

geologic, water-supply, and water-quality studies;

and to analyze the availability and variability of

streamflow. When based on many years of record, 

these curves can indicate the probable future behavior of a stream given that the physical characteristics

of the basin will not be significantly altered 

(Gillespie and Schopp, 1982). 

The flow of water past a point on a stream is measured at a 

streamflow-gaging station. Streamflow records integrate the 

effects of climate, topography, and geology, and show the 

distribution and magnitude of runoff in time.
64

1 2 5 10 20 30 40 50 60 70 80 90 95 98 99

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

0.01

10

0.015

0.02

0.025

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0.15

0.2

0.25

0.3

0.4

0.5

0.6

0.7

0.8

0.91

1.5

2

2.5

3

4

5

6

7

8

9

DISCHARGE, IN CUBIC FEET PER SECOND PER SQUARE MILE

Flat Brook near Flatbrookville, N.J.

(Valley and Ridge Physiographic Province)

Great Egg Harbor River at Folsom, N.J.

(Coastal Plain Physiographic Province)

South Branch Raritan River near High Bridge, N.J.

(New England Physiographic Province) 

Stony Brook at Princeton, N.J.

(Piedmont Physiographic Province)

Figure 21. Flow-duration curves for four stream sites 

in different physiographic provinces in New Jersey. 

The shape of a stream’s flow-duration curve depends 

on the geologic and hydrologic characteristics of its 

drainage basin. Areas that are rocky and have thin 

soils have little ground-water storage; therefore, 

streams in these areas, such as the Piedmont 

Physiographic Province, have steeply sloping flowduration curves. Areas that have thick deposits of 

sand and gravel have substantial ground-water 

storage; therefore, streams in these areas, such 

as the Coastal Plain Physiographic Province, have 

relatively flat flow-duration curves. 
65

Great Egg Harbor River at Sicklerville, New Jersey, where ground-water discharge makes up 

roughly 85 percent of total streamflow. (Photograph by Jonathan Kennen)

Base flow

Streams in New Jersey always seem to flow,

except during the driest periods. Although the water 

level may be low after a period of no precipitation, 

the stream still flows. Where does the water come

from? Sustained, or fair-weather, streamflow is

called base flow--which in most cases is simply the 

ground-water contribution to streamflow (groundwater discharge). Streamflow after a storm is composed of overland runoff, precipitation that falls

directly onto the stream, interflow, and ground-water

discharge. During fair weather, no precipitation is

available; therefore, ground water discharged into 

the stream makes up streamflow. In some cases,such 

as where effluent from wastewater-treatment facilities or reservoir water is released into the stream to

maintain a constant flow, base flow is composed not

exclusively, but mainly, of ground-water discharge.

Base flow can be affected by various human 

activities. Withdrawals from the stream (for municipal use, irrigation, or cooling, for example) or discharges to the stream (industrial or wastewater

discharge, for example) are the most common human 

activities that directly affect streamflow. Development of a watershed can affect base flow by removing wastewater from the basin; reducing the amount

of recharge to the aquifer and, ultimately, the amount 

of ground water that discharges to the stream; and 

increasing ground-water withdrawals. Reduced base

flow in turn may degrade or destroy the habitat for

aquatic animals, reduce the amount of water available to dilute contaminants in the stream, and reduce 

the amount of water available to users downstream 

who depend on the stream for water supply.

In New Jersey, the amount of base flow in a

stream depends mainly on the geology and degree of

development in the watershed. In the Coastal Plain 

Physiographic Province, the ground-water contribution to streamflow ranges from about 65 to 95 percent. Base flow in streams in more highly developed 

areas or areas where sand deposits are thin or clay

units are prevalent typically range from 65 to 75 percent. Many of these streams are located in the Lower 

Delaware water region. Base flow in streams in areas

with thick sand and gravel deposits and little development, such as the Atlantic Coastal water region, is

typically 80 to 95 percent. In northern New Jersey, 

where the geology is more variable, the range in the 

ground-water contribution to streamflow also is

greater--22 to 88 percent (CH2M Hill and others, 

1992, Task 2 Report). In rocky areas with little or no

sediment cover, the ground-water contribution to

streamflow is small because ground-water storage 

capacity is minimal. In areas with thick glacial

deposits and (or) carbonate rocks with solution channels that can store large amounts of ground water, the 

ground-water contribution to streamflow is large.

(Base-flow values, except where noted, are compiled 

from Watt and Johnson, 1992; Watt and others, 1994;

Johnson and Watt, 1996; Johnson and Charles, 1997;

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

Geological Survey, written commun., 1999; A.C. 

Kane, E.G. Charles, and D.A. Storck, U.S. Geological Survey, written commun., 1999; and unpublished

data on file at the U.S. Geological Survey District

Office, West Trenton, New Jersey.)
66

Flood on the Delaware River, Stacy Park, New 

Jersey, August 28, 1955. (Photograph by Jerry 

Ludlow)

Flood-prone areas and wetlands

Flooding has long been a problem in many 

areas of the State. Loss of lives and property due to

flooding can be substantial. In New Jersey, precipitation is fairly evenly distributed throughout the year, 

but flooding tends to occur during winter and early

spring as a result of widespread, steady rain of moderate intensity that falls on frozen ground and therefore cannot infiltrate. In addition, accumulated snow

and ice may melt and increase runoff to the streams, 

increasing the chance of flooding. Summer storms

tend to be more short-lived and of greater intensity.

Summer thunderstorms typically are of local extent 

and may cause small streams to flood. Major floods 

of great magnitude and areal extent that resulted in

loss of life and property hit New Jersey in 1903, 

1940, 1955, 1971, and 1984. Of these, the first four 

were caused by summer storms; the 1984 flood was

caused by a spring storm. (See U.S. Geological Survey, 1991.)

Because parts of New Jersey are densely populated, flood planning is a necessity. Flood-warning

systems and knowledge of flood-prone areas are

essential for protecting lives and property. In New 

Jersey, the USGS, in cooperation with Somerset

County, the National Weather Service, and the U.S. 

Army Corps of Engineers, has implemented floodwarning systems in the Passaic River Basin, in Somerset County, and in several small watersheds

(fig. 19). These flood-warning systems consist of 

streamflow-gaging stations and precipitation gages 

that continuously monitor streamflow and rainfall. 

These data are transmitted by radio, telephone, and 

satellite to officials to alert them to any threat of

flooding. Streamflow-gaging stations and precipitation stations are distributed throughout the watersheds and at critical flood-prone locations to provide 

the best real-time information available to predict

flooding. These data allow for efficient emergency 

evacuations of high-risk areas. Hydrologic data gathered from this network of sites also are useful for

planning for future water-supply needs, assisting in 

monitoring surface-water quality, responding early

to hazardous-waste spills, planning for environmental concerns and development, and optimizing the 

design of bridges, dams, and levees (Summer,

1998b, 1998c).

To minimize the effects of flooding, State and

local governments regulate development in floodplains. In New Jersey, the NJDEP distributes flood

maps and flood-elevation data, provides flood-preparedness and flood-recovery assistance, regulates 

floodplain development through permits, and coordinates the National Flood Insurance Program operated by the Federal Emergency Management Agency

(FEMA). FEMA produces maps of “special floodhazard areas” in a community. These are areas that

are subject to inundation during the 100-year and 

500-year floods (Federal Emergency Management 

Agency, 1988). The 100-year flood is a flood that has 

a 1-percent probability of being equalled or

exceeded during any given year. This is the National

standard on which floodplain management and 

insurance requirements are based (Federal Emergency Management Agency, 1988). The 500-year

flood is a flood with a 0.2-percent chance of being

equalled or exceeded in any given year. Mapping the 

500-year flood is for information purposes and 

chances of flooding outside the 500-year flood designation are considered to be very small.
67

Wetlands are unique surface-water features 

that are found throughout New Jersey but predominantly in the Coastal Plain (figs. 2a-e). Wetlands

form where water is at or near the land surface, most

commonly along rivers and in low-lying coastal

areas. They are characterized by particular types of

vegetation and (or) soils. In inland areas, impervious

clays can restrict vertical movement of water and

wetlands can be formed. Wetlands can receive water

from the surrounding area, can recharge the surrounding area, or both (Winter and others, 1998) (fig. 

22). Wetlands are beneficial in many ways. They

provide spawning areas for fish and shellfish; food 

and migrating and wintering locations for birds; and 

homes, food, and shelter for animals(beavers, foxes,

rabbits, and mice) and reptiles (U.S. Geological Survey, 1996c). Wetlands also provide flood- and stormdamage protection, erosion control, and public water 

supply, and support production of economically 

important crops such as blueberries, cranberries, 

wild rice, salt hay, and timber (U.S. Geological Survey, 1996c). Wetlands also act as water-quality “filters” by absorbing nutrients, trace elements, and

other contaminants from the water that flows 

through them, and are recreational areas for boating,

hunting, painting, and photography (U.S. Geological

Survey, 1996c).

Figure 22. Schematic diagrams showing groundwater flow associated with wetlands. The source of 

water to wetlands can be (A) ground-water discharge 

where the land surface is underlain by complex 

ground-water flow fields, (B) ground-water discharge 

at seepage faces and at breaks in slope of the water 

table, (C) streams, and (D) precipitation where 

wetlands have no stream inflow and the water table 

slopes away from the wetland. (From Winter and 

others, 1998)

Direction of ground-water flow

Water table

Land surface

D Wetland

Direction of ground-water flow

Water table

Land surface

Wetland

C

Stream

Direction of ground-water flow

Water table

Land surface

B

SEEPAGE FACE

BREAK IN SLOPE

Areas favorable for

wetland formation

Land surface

A COMPLEX FLOW FIELDS

Zone of low permeability

Water table

Direction of

ground-water

flow

Area favorable for

wetland formation

Line of equal

hydraulic

head

Zone of high permeability
68

In New Jersey, wetlands have been destroyed 

to provide land for crop production, housing, industrial development, transportation, and landfills. The

quality of the water in wetlands has been degraded 

by agriculture, logging, industrial discharge, municipal waste, and urban runoff. Federal and State government and private organizations are working to

restore and maintain the integrity of the State’s wetlands.

Wetlands are beneficial in many

ways. They provide spawning

areas for fish and shellfish; food

and migrating and wintering 

locations for birds; and homes, 

food, and shelter for animals and 

reptiles. Wetlands also provide 

flood- and storm-damage

protection, erosion control, and 

public water supply, and support 

production of economically

important crops such as

blueberries, cranberries, wild rice, 

salt hay, and timber.

Lakes and reservoirs

New Jersey has 1,200 lakes, including 380 

public lakes that occupy a total of 24,000 acres (fig. 

2a-e). Many of New Jersey’s lakes are natural, but

many others, both public and private, are impoundments on streams. Public lakes may be used for recreational purposes such as swimming, boating, and 

fishing for both native and stocked species (N.J. 

Department of Environmental Protection, Environmental Indicators Technical Reports, June 1998, 

accessed March 23, 2000, on the World Wide Web at

URL http://www.state.nj.us/dep/dsr/

neppspub3.htm#WATERRESOURCESSECTION, 

text format).

Lakes, like wetlands and streams, interact with

the ground-water system (table 5). Some lakes

receive ground-water inflow over their entire bed,

some have seepage loss to ground water over their

entire bed, and some receive inflow through part of

their bed and have seepage loss to ground water 

through other parts (Winter and others, 1998). Reservoirs are man-made structures built along streams, 

typically for water-supply or water-storage purposes. 

Lakes and reservoirs, unlike streams, are greatly 

affected by evaporation because of their large surface areas. Water levels in reservoirs and streams can

change rapidly, whereas those in lakes tend to be

fairly stable. The USGS measures and reports the 

stage and change in contents in selected lakes and 

reservoirs throughout the State. 

Organic deposits that line the beds of lakes and

reservoirs affect the distribution of the seepage and 

the chemical reactions that occur between the sediments and water (Winter and others, 1998). Large

concentrations of nutrients, such as nitrogen and 

phosphorus, that typically enter a lake in runoff from 

urban and agricultural areas can, over a long period

of time, adversely affect the quality of water in lakes 

and eventually render them unusable for water supply and (or) recreation. This process, called eutrophication, occurs naturally but can be accelerated as a

result of the inputs of large amounts or excessive 

concentrations of nutrients and suspended sediments 

from point and nonpoint sources. Eutrophic lakes are 

characterized by high concentrations of suspended 

sediments, nutrients, and algae. Excessive plant 

growth may be present, and fish kills may occur as a

result of fluctuations in concentrations of dissolved

oxygen. 
69

Wanaque Reservoir, New Jersey. (File photograph, 

U.S. Geological Survey, West Trenton, New Jersey)

Table 5. Characteristics of surface-water bodies

Characteristic Stream Lake Reservoir Wetland

Interacts with ground-water system x x x x

Human-made structure x

Greatly affected by evaporation x x x

Water level changes rapidly x x

Organic deposits line bottom x x x
70

As part of the Clean Lakes Program, the

NJDEP Bureau of Freshwater and Biological Monitoring has evaluated the condition of 116 public

lakes with known water-quality problems or whose

water quality was previously unknown. Of the 116 

lakes evaluated, 113 are considered to be eutrophic.

Lakes that are found to be eutrophic may be treated, 

typically by dredging and (or) application of aquatic

pesticides, to restore their aesthetic and recreational

value. (See N.J. Department of Environmental Protection, Environmental Indicators Technical

Reports, June 1998, accessed March 23, 2000, on the

World Wide Web at URL http://www.state.nj.us/dep/

dsr/neppspub3.htm#WATERRESOURCESSECTION, text format).

The locations of New Jersey’s major reservoirs are shown in figure 6; selected information 

about them islisted in table 1. The cumulative capacity of the lakes and reservoirs in New Jersey is shown 

in figure 23. Since 1900, the total capacity of all the

reservoirs has increased from roughly 30 to 200 billion gallons. The need for surface-water storage has 

increased along with the State’s population.

Although the aquifers in northern New Jersey can

provide significant amounts of ground water, their

yield is insufficient to meet the needs of the public 

(U.S. Geological Survey, 1990); therefore, reservoirs

are a necessity.

1890 1900 1920 1940 1960 1980 1990

220

0

20

40

60

80

100

120

140

160

180

200

CUMULATIVE CAPACITY, IN BILLION GALLONS

1,200

0

200

400

600

800

1,000

POPULATION, IN PEOPLE PER SQUARE MILE

Population

Cumulative capacity

Figure 23. Cumulative capacity of selected large 

reservoirs and lakes and population of New Jersey 

from 1890 to 1990. The need for increased reservoir 

capacity is a result of the growth in population. The 

aquifers, especially those in northern New Jersey, 

yield significant amounts of water but are unable to 

meet the demands of the growing population, making 

the reservoirs a crucial part of New Jersey’s overall 

water-supply plan. 

1910 1930 1950 1970
71

Ground-Water Data

Ground-water levels

The USGS maintains a network of observation 

wells in New Jersey for the purpose of monitoring 

ground-water levels throughout the State. Changes 

in water levels reflect the general response of the 

ground-water system to natural climate changes, 

changes in recharge patterns, and ground-water

withdrawals. Automatic water-level recorders are 

used on some of the wells to obtain the continuous, 

long-term record that is needed to evaluate the 

effects of climate changes on the ground-water system, to develop a data base that can be used to measure the effects of development, to facilitate the

prediction of future ground-water supplies, and to

provide data for ground-water-resource management 

(Jones and DeLuca, 1998). Ground-water levels typically are measured in about 200 wells throughout

the State during any given year (fig. 24). Roughly 25 

percent of the wells are completed in stratified drift 

or shale, siltstone, sandstone, limestone, dolomite, 

and conglomerate rock units in the northern physiographic provinces. Of the 25 percent, half are completed in the stratified drift and half are completed in

the consolidated-rock aquifers. Wells completed in

stratified drift range from 50 to 200 ft in depth; wells

completed in consolidated-rock aquifers range from

20 to about 700 ft in depth. Seventy-five percent of

the ground-water observation wells in New Jersey 

are in the Coastal Plain Physiographic Province.

About 30 percent of the wells in the Coastal Plain are 

completed in unconfined aquifers. The KirkwoodCohansey aquifer system is the most heavily monitored, but water levels also are measured in wells 

completed in the Holly Beach water-bearing zone, a

minor unconfined aquifer in Cape May County.

Water levels are measured in wells completed in the 

typically confined upper and middle Potomac-Raritan-Magothy aquifers and the Englishtown aquifer

system where they reach the land surface (crop out) 

and are unconfined. About 70 percent of the wells in

the Coastal Plain are completed in confined aquifers.

Wells are completed in the confined Piney Point, 

Vincentown, and Wenonah-Mount Laurel aquifers 

and the Kirkwood-Cohansey, Englishtown, and 

Potomac-Raritan-Magothy aquifer systems. The 

depths of the observation wells in the Coastal Plain 

range from about 10 ft in the Kirkwood-Cohansey 

aquifer system to more than 2,000 ft in the PotomacRaritan-Magothy aquifer system. One well, 5.3

miles offshore from Atlantic City, was drilled in

1986 to gather information on fresh-ground-water 

levels and salinity (chloride concentrations) off the 

Atlantic City coast.

75 74

41

40

39

0 10 20 KILOMETERS

0 10 20 MILES

PENNSYLVANIA

CONNECTICUT

NEW YORK

DELAWARE

ATLANTIC OCEAN

Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

Valley and Ridge

New England

Piedmont

Fall Line

Coastal Plain

Extent of 

Wisconsin

glaciation

LOCATION OF U.S. GEOLOGICAL

SURVEY MONITORING WELLS--

EXPLANATION

Completed in the unconfined 

aquifers of the Coastal Plain

Completed in the confined 

aquifers of the Coastal Plain

Open to fractured rock

Open to stratified drift

Figure 24. U.S. Geological Survey ground-water 

monitoring wells active in New Jersey in 1997. Water 

levels in these wells are monitored to evaluate the 

effects of development and climatic changes on the 

ground-water system. Long-term water-level 

measurements also can assist in the prediction of 

future ground-water availability and supply data for 

ground-water-resource management.
72

Two water-level hydrographs--one for a well

that is completed in the unconfined KirkwoodCohansey aquifer system and the other for a well that

is completed in the confined Potomac-Raritan-Magothy aquifer system--are shown in figure 25. The 

water level in the well that is completed in the unconfined aquifer system varies more because it rises in

response to the infiltration of precipitation and falls

with the discharge of ground water to surface-water 

bodies. The water level in the well that is completed

in the unconfined aquifer system is affected more

quickly than the water level in the well that is completed in the confined aquifer system by rainfall and 

climatic events such as long wet or dry periods.

Water levels typically are highest in winter and early 

spring as a result of little or no evapotranspiration,

low temperatures, and snowmelt and spring rains 

that recharge the aquifer. Ground-water levels typically start to decline as summer begins and continue

to decline until late fall. Water use is highest in summer when more water is used for irrigation and recreation, and more water evaporates and transpires. 

Water levels typically are lowest in late fall, and rise

again during winter, completing the cycle. 

1989 1990 1991 1992 1993 1994 1995 1996 1997

17

26

18

19

20

21

22

23

24

25

WATER LEVEL, IN FEET BELOW LAND SURFACE

Well completed in the unconfined aquifer

1989 1990 1991 1992 1993 1994 1995 1996 1997

120

155

125

130

135

140

145

150

WATER LEVEL, IN FEET BELOW LAND SURFACE

Well completed in the confined aquifer

Figure 25. Hydrographs of water levels measured in 

observation wells in the Coastal Plain of New Jersey, 

1988-98. Water levels in the well completed in the 

unconfined aquifer fluctuate rapidly because they rise 

and fall in response to climatic changes. Water levels 

in the well completed in the confined aquifer are 

buffered from short-term climatic changes; therefore, 

their response to precipitation is slow and they tend 

to rise and fall cyclically. 

missing data

Water levels are rising in response 

to reductions in withdrawals in 

Critical Area 1 that were imposed 

in 1989. 

1988 1998

1988 1998

Changes in water levels reflect the general 

response of the ground-water system to natural

climate changes, changes in recharge patterns, 

and ground-water withdrawals.
73

In contrast, water levels in wells that are completed in confined aquifers tend to fluctuate less than 

those in wells that are completed in unconfined aquifers. Because confined aquifers are buffered from

short-term climatic changes, their response to rainfall is more gradual. Changes in water levels in the

heavily used Potomac-Raritan-Magothy aquifer system are caused primarily by ground-water withdrawals.

Water levels in observation wells are measured by different methods. About half the observation wells throughout the State are equipped with

automatic recorders that record the water levels

hourly. This type of data collection gives the most

complete and accurate information of the methods 

used. A few wells are equipped with recorders that

indicate only the maximum and minimum water

level over a period of time. These water levels are 

not associated with any particular times other than

the period between visits by USGS personnel. The 

water levels in the remaining one-quarter of the wells

are measured manually two to six times per year.

Measurement methods used in a given well may 

change over the period of record. Water-level measurements can be plotted on a map to obtain a 

regional perspective on water levels and to determine ground-water-flow directions. (See Box D.) 

The USGS has documented the water levelsin

the confined aquifers of the New Jersey Coastal 

Plain on a regular basis since 1978. Every 5 years

USGS personnel measure water levels in approximately 1,000 wells over a 4- to 5-month period in 

late fall to assess the status of the water supply.

Results of these studies have been used by NJDEP to

develop withdrawal regulations and to establish the 

Water-Supply Critical Areas.

Four ground-water-monitoring recorders, each 

completed in a different hydrologic unit at

Picatinny Arsenal, New Jersey. (Photograph by 

Eric Vowinkel)
74

 Water levels in wells that are completed in an unconfined aquifer can be used to produce a 

water-table map, which is a representation of the configuration of the water table, or the top of 

the saturated zone. Similarly, water levels in wells that are completed in a confined aquifer can 

be used to produce a potentiometric-surface map, which is a representation of the aquifer's 

potentiometric surface, or the level to which water will rise in tightly cased wells (Fetter, 1980). 

The water table, then, is a particular type of potentiometric surface that occurs in an unconfined 

aquifer. 

 Water in a confined aquifer typically is under pressure. This causes the water in the well to rise 

to a level above the top of the aquifer. This type of well is called an artesian well. If the pressure is

sufficient to cause water to flow from the well at land surface, the well is called a flowing artesian 

well.

 The shape of the water table is controlled principally by the topography as the ground water 

flows from recharge areas (topographic highs) to discharge areas (topographic lows). The water 

table, therefore, tends to be a subdued replica of the topography. Streams also affect the shape of 

the water table. Where the water table intersects a stream channel, the water-table contour has a 

“v” shape. For a gaining stream--one that receives ground-water discharge-- the “v” points 

upstream because water is flowing into the stream. For a losing stream--one that loses flow to 

the ground-water system--the “v” points downstream because water is flowing into the stream 

banks. A potentiometric-surface map is much "smoother" than a water-table map because 

topography has little effect on water levels in a confined aquifer. 

 On water-table and potentiometric-surface maps, the direction of the ground-water flow typically 

is approximately perpendicular to the water-level contours. In northern New Jersey, however, where 

the rocks are fractured and folded, the direction of ground-water flow can be harder to determine. 

Because the ground-water system is dynamic, all water levels used to construct a water-level map 

should be measured at approximately the same time.

D

Constructing a water-table or potentiometric-surface map

74
75

150

140

130

120

150

140

130

120

138.47

131.42

152.31

145.03

132.21

126.78 137.90

121.34 128.37

a

LOCATION OF WELL AND

ALTITUDE OF WATER

TABLE ABOVE SEA

LEVEL, IN FEET

WATER-TABLE CONTOUR--

Shows altitude of water table.

Contour interval 10 feet. Datum

is sea level

GROUND-WATER FLOW

LINE

152.31

EXPLANATION

138.47

131.42

152.31

145.03

132.21

126.78 137.90

121.34 128.37

b

138.47

131.42

152.31

145.03

132.21

126.78 137.90

121.34 128.37

c

Unsaturated zone

Land surface

Water table

Confined aquifer

Surface water

D-1. The water table is the upper surface of the

saturated zone. The water table meets surface-water bodies

at or near the shoreline if the surface-water body is connected 

to the ground-water system.

D-2. Using known altitudes of the water table at individual

wells (a), contour maps of the water-table surface can be

drawn (b), and directions of ground-water flow along the 

water table can be determined (c) because ground-water 

flow is approximately perpendicular to the contours.

Confining unit

Unconfined aquifer

(saturated zone)

water

levels

Unconfined well

Confined well

D-3. Gaining streams receive water from the

ground-water system (see fig. 4). This can be 

determined from water-table contour maps 

because the contour lines point upstream 

where they cross the stream.

Losing streams lose water to the groundwater system (see fig. 4). This can be 

determined from water-table contour maps 

because the contour lines point downstream 

where they cross the stream.

(D-1) Water levels in unconfined and confined aquifers. (D-2) The making of a water-table map. (D-3) Examples of gaining 

and losing streams. (From Winter and others, 1998)

Ground-water flow line

Water-table contour

Stream

100

90

80

70

Stream

Ground-water flow line

20

30

40

50

60

20

30

40

50

60

70

Water-table contour

75
76

In 1986, the NJDEP designated two WaterSupply Critical Areas in the New Jersey Coastal

Plain (fig. 26). These areas were established in an

attempt to manage withdrawals from aquifers in

which water-level declines were a matter of concern.

Withdrawals from specified aquifers were cut back

and new allocations (with the exception of temporary construction dewatering and ground-water 

remediation activities) were limited. Critical Area 1 

is located in Middlesex, Monmouth, and Ocean 

Counties. Withdrawals from the Wenonah-Mount

Laurel aquifer, Englishtown aquifer system, and

upper and middle Potomac-Raritan-Magothy aquifers in this area were restricted beginning in 1989.

Early in water year 1991, long-term water-level 

declines began to reverse in observation wells that

are completed in these aquifers in southern Monmouth and northern Ocean Counties. Ground-water

withdrawals in this area were reduced and replaced

by surface-water withdrawals for public supply or

were shifted to shallower, unconfined aquifers. By 

water year 1997, water levels in the Potomac-Raritan-Magothy aquifer system were leveling off, but 

those in the Englishtown aquifer system and the 

Wenonah-Mount Laurel aquifer were continuing to

rise in some places. The hydrograph in figure 25 is

an example of the rise in water levelsin the PotomacRaritan-Magothy aquifer system over time. (See 

Jones and DeLuca, 1998.)

Critical Area 2 is located in Camden, most of

Burlington and Gloucester, and parts of Atlantic, 

Cumberland, Ocean, Monmouth, and Salem Counties. Restrictions have been imposed on withdrawals 

from the upper, middle, and lower Potomac-RaritanMagothy aquifers since 1996. Current data show that

water-level declines in these aquifers have stopped. 

(See Jones and DeLuca, 1998.)

Water-Supply Critical Area--

From N.J. Department of

Environmental Protection

unpublished, 1:250,000.

Boundaries are approximate

and should not be used for

regulatory compliance

purposes.

Figure 26. Location of Water-Supply Critical Areas in 

New Jersey. These areas were designated to help 

control the decline in water levels in some of the 

confined aquifers. Restrictions on withdrawals in 

Critical Area #1 began in 1989, and water levels in 

some of the aquifers began to recover in 1991. 

Restrictions on withdrawals in Critical Area #2 began 

in 1996, and water levels in some of the aquifers 

have since stabilized.

EXPLANATION

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Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

SUSSEX

MORRIS

BERGEN

ESSEX

UNION HUDSON

MIDDLESEX

MERCER MONMOUTH

SOMERSET

HUNTERDON

WARREN

OCEAN

BURLINGTON

ATLANTIC

GLOUCESTER CAMDEN

SALEM

CUMBERLAND

CAPE

MAY

PASSAIC

Critical Area #1

Critical Area #2
77

Water tower for public supply in central New

Jersey. (Photograph by Eric Vowinkel)

Major withdrawal wells

Many large public supply wells are completed 

in aquifers in the New Jersey Coastal Plain (fig. 27).

The volume of ground-water withdrawals depends

on the extent of the aquifer, the population, and the

presence of other sources of water.

The greatest withdrawals from a single aquifer

in the Coastal Plain are from the unconfined Kirkwood-Cohansey aquifer system. Withdrawals from 

this aquifer system have increased since 1991 

because of increased development, increased irrigated land, and restrictions on withdrawals from the 

deeper, confined aquifers (J.P. Nawyn, oral commun., 1999). Water is withdrawn from the Kirkwood-Cohansey aquifer system throughout the 

Coastal Plain, but withdrawals are concentrated in

northern Ocean County and around the Atlantic City

area. The withdrawals from each of the three aquifers of the Potomac-Raritan-Magothy aquifer system

are nearly equal, and amount to roughly 60 percent 

of the volume withdrawn from the KirkwoodCohansey aquifer system. The Upper and Middle 

Potomac-Raritan-Magothy aquifers are used most 

heavily along the Delaware River near Camden and 

in the northern part of the Coastal Plain in Monmouth and Ocean Counties. The Lower PotomacRaritan-Magothy aquifer also is used heavily, but 

only around the Camden area. The areas in which 

water from the Potomac-Raritan-Magothy aquifer 

system is used most heavily correspond to the watersupply critical areas. Cutbacks in the withdrawals

from these confined aquifers have been accompanied by increased withdrawals from the KirkwoodCohansey aquifer system. The Atlantic City 800-foot

sand is used moderately along the coast. Withdrawals from this aquifer amount to about 30 percent of

the volume withdrawn from the Kirkwood-Cohansey aquifer system. The Piney Point (not shown in

figure 27) and Wenonah-Mount Laurel aquifers and 

the Englishtown aquifer system are the least used of

the Coastal Plain aquifers. The combined withdrawals from these three aquifers are less than those from 

the Atlantic City 800-foot sand. 

Ground-water withdrawals in northern New 

Jersey equal about 60 percent of the total withdrawals from the Coastal Plain aquifers. These withdrawals are shown by aquifer type in figure 28. The 

glacial valley-fill aquifers, composed of stratified

drift, are the most heavily used and most productive 

aquifers in northern New Jersey, accounting for more

than 50 percent of the total ground-water withdrawals. Because glaciers covered and deposited sediments over most of northern New Jersey, these

aquifers are found in all three of northern New Jersey’s physiographic provinces. Withdrawals from 

the sandstone, shale, and mudstone aquifers in the 

Piedmont Physiographic Province account for more

than 35 percent of the total ground-water withdrawals. The highest yielding aquifers are those that are

composed of rocks that are highly weathered, 

jointed, and fractured. Crystalline-rock aquifers in

the New England Physiographic Province and limestone and shale aquifers in the Valley and Ridge 

Physiographic Province account for only 10 percent 

of the total ground-water withdrawals in northern

New Jersey. Limestone aquifers can produce significant amounts of water, especially when they are fractured, weathered, or covered by glacial material.

Crystalline-rock and shale aquifers typically have

low yields, except where they have been weathered 

and (or) fractured.
78

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A

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EXPLANATIO

Figure 27. Location and amount of water withdrawn for public supply from the major aquifers in the Coastal Plain of New Jersey in 199centered on the locations of withdrawals from each of the aquifers. Water withdrawals from an aquifer depend on the location of the pextent of the aquifer, how easily the water can be obtained, and the quality of the water. Each aquifer has a unique pattern of withdraw

Ground-water withdrawals, 

Data fro(USGS) Data Syon file aTrenton

Greater than 500

Less than 100

100-199

200-299

300-399400-499

KirkwoodCohanseyaquifer system

Atlantic City800-foot sand

Englishtownaquifer system

WenonahLaurel aq

Lower PotomacRaritan-Magothyaquifer

Middle PotomacRaritan-Magothy aquifer

Upper PotomacRaritan-Magothyaquifer
79

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NEW YORK

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Base from U.S. Geological Survey digital linegraph files, 1:24,000

Crystalline, limestone, and shale aquifers

(New England and Valley and Ridge

Physiographic Provinces)

Sandstone, shale, and 

mudstone aquifers

(Piedmont Physiographic Province)

Glacial valley-fill aquifers

(New England, Valley and Ridge, and

Piedmont Physiographic Provinces)

Watershed MFrom N.J. DeProtection, 11997

EX

Figure 28. Location and amount of water withdrawn for public supply from aquifers in northern New Jersey in 1997.Circles on the maps are centered on the locations of withdrawals from each of the aquifer types. Water withdrawals from an aquifer depend on the location of the population to be served, the extent of the aquifer, how easily the water can be obtained, and the quality of the water. Withdrawals in the New England and Valley and Ridge Physiographic Provinces are primarily from crystalline aquifers and limestone and shale aquifers, respectively. Withdrawals in the Piedmont Physiographic Province are primarily from sandstone, shale, and mudstone aquifers. Glacial valley-fill aquifers cover all three physiographic provinces and supply the most water.

Ground-water w

Greater than 

Less than 10

100-199

200-299

300-399400-499
80

Excessive growth of Lemnaceae (duckweed) 

caused by excessive nutrient runoff, Lamington 

River at Ironia, New Jersey. (Photograph by Robert Nicholson)

Water-Quality Data

The ability of a water supply source to meet

current and future demands depends not only on the 

quantity of water available but also on its quality.

The quality of water that is unaffected by human 

activities is called “background” water quality. The

addition of contaminants to the water supply alters

the background water quality, and any substance that

is present in the environment in concentrations 

greater than background levels can be considered to 

be a contaminant (Gough and others, 1993). The difference between background levels and those considered to constitute contamination can be very

small.

Contaminants are derived from either “point”

or “nonpoint” sources. Point sources, such as a

chemical spill, effluent from a leaking septic tank, or 

discharge from an industrial facility or sewage-treatment plant, typically are relatively constant sources 

of a large quantity of contaminants in a readily identifiable location. Often these sources cause dramatic

and immediate changes to the water quality. Nonpoint sources, such as lawns or farm fields to which 

pesticides or fertilizers have been applied, urban runoff, atmospheric deposition, or soil erosion, typically

constitute smaller quantities of contaminants and are 

more diffuse and harder to identify than point

sources. The effects of nonpoint-source contamination are usually subtle and gradual.

Contaminants can occur naturally (for example, radon) or be the result of human activities (for

example, the application of pesticides). Radon is a 

radioactive gaseous element that occurs naturally in

rocks and soils as a result of the radioactive decay of

thorium and uranium--elements that are concentrated in rocks in certain parts of New Jersey (Gough 

and others, 1993). High concentrations of radon can 

cause health problems (U. S. Environmental Protection Agency, unpub. data titled Radon Health Risks,

frequently asked questions, accessed January 21, 

1999, on the World Wide Web at URL http://

www.epa.gov/iaq/radon/radonqa1.html, text format). Other naturally occurring contaminants

include iron, which is not toxic to humans but can

clog pipes, stain laundry, and discolor water when 

present in high concentrations. Sulfur is responsible

for the “rotten egg” odor in some water supplies. 

Swamps and marshes commonly contain acidic and

colored water, such as the “cedar waters” in the New 

Jersey Pinelands. 

Contaminants that result from human activities or whose naturally occurring concentrations can 

be increased by human activities include pathogens

(disease-causing microorganisms), nutrients, 

organic compounds, trace elements, sediment, and 

debris. Pathogens in our watersheds are bacteria and

viruses that come from human and animal fecal

waste. Faulty septic systems and leaking sewer lines, 

improper boat sanitation disposal, and wild, farm, 

and domestic animal waste all contribute to the problem. Pathogens can force us to close our beaches and

restrict shellfish harvesting. Organic compounds

such as pesticides, polychlorinated biphenyls 

(PCB’s), oil, grease, gasoline, and chemicals used in

our homes, gardens, and yards may be harmful to

humans and aquatic life. Sources of trace elements

include industrial-waste discharges, mining, acidrain drainage, and film-processing wastes(Manahan,

1990). Sediments include dirt, sand, and gravel that

are eroded from farm fields, roadways, and construction sites. These materials can clog our streams, alter 

streamflow, and degrade the aquatic habitat. Debris, 

or trash, also clogs our waterways and is a threat to

aquatic life (Chester Arnold and Melissa Beristain,

University of Connecticut Cooperative Extension 

System, Hamden, Conn., Nemo project factsheet #2, 

accessed July 1, 1999, on the World Wide Web at

URL http://www.lib.uconn.edu/CANR/ces/nemo, 

text format).
81

Some elements, such as nitrogen and phosphorus, occur naturally in our environment. They are 

essential for the health and growth of humans, animals, and plants (Gough and others, 1993), but may 

be toxic if present in drinking water in concentrations greater than natural background levels. Nitrogen and phosphorus, commonly called nutrients, are 

added to the environment in many ways. They can be

derived from commercial fertilizers, sewage-treatment plants, faulty septic systems, animal waste,

atmospheric inputs from oil- and coal-burning industries, car and truck emissions, and lawn and yard 

maintenance (Puckett, 1995). 

Nutrients cycle through the environment from

soil to plantsto animals and back to soil. As nitrogen

moves through this cycle it is incorporated into various compounds, including nitrate, nitrite, ammonium, and organic compounds (for example, 

proteins). Plants and animals decompose and add 

organic matter to the soil. Bacteria in the soil convert

the organic matter to a form that is usable by plants. 

People and animals eat the plants and their waste 

returns nitrogen to the soil. Nitrogen gas is removed 

from the atmosphere by certain plants through nitrogen fixation and is released as the plants decay. The 

decaying plants produce ammonium ions, which are

converted by microorganisms in the soil to nitrate

(Manahan, 1990). 

High concentrations of nitrogen, in the form of 

nitrate or nitrite, in ground water that is used for 

water supply can cause methemoglobinemia (“bluebaby syndrome”) in infants. Nitrate washed into

streams and lakes by runoff can cause an overgrowth

of algae and weeds that eventually die, depleting the 

water of oxygen that sustains the fish and other 

aquatic life. High concentrations of phosphorus contribute to excessive algal growth and is the major 

cause of eutrophication in lakes (Manahan, 1990).

U.S. Geological Survey’s surface-water-quality

sampling site on the Neshanic River at Reaville, 

New Jersey. (Photograph by Jonathan Kennen)

Surface-water quality

Scientists who study the quality of water need

to know how nitrogen and phosphorus move through

the ground- and surface-water systems. Nitrogen (as 

nitrate), for example, is very soluble in water and,

therefore, very mobile. It can easily leach into the

ground water with recharge, or can be washed into

nearby streams from lawns and farm fields that have 

been treated with fertilizer. Phosphorus (as phosphate), in contrast, is less mobile and binds to sediments.

Concentrations of nitrate and phosphate in

streamflow before, during, and after a storm are 

shown in figure 29. The initial concentration of 

nitrate in the stream is diluted as a large influx of

overland flow reaches the stream and the streamflow 

peaks. As the storm passes and runoff decreases, the 

nitrate concentration begins to rise again. This indicates that the nitrate in the stream is derived predominantly from ground-water discharge rather than 

from overland flow. 
82

0 9 1 2 3 4 5 6 7 8

TIME, IN HOURS

0

5

1

2

3

4

DISCHARGE, IN CUBIC FEET PER SECOND

0.4

2.2

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

CONCENTRATION, IN MILLIGRAM PER LITER

Discharge

Nitrate

concentration

0 9 1 2 3 4 5 6 7 8

TIME, IN HOURS

0

5

1

2

3

4

DISCHARGE, IN CUBIC FEET PER SECOND

0.05

0.35

0.10

0.15

0.20

0.25

0.30

CONCENTRATION, IN MILLIGRAMS PER LITER

Discharge

Phosphate

concentration

a

b

Figure 29. Concentrations of two nutrients, nitrate 

and phosphate, in streamflow during a typical storm. 

Nitrate and phosphate, because of their physical 

properties, act differently during storms. Nitrate 

dissolves easily in water, but phosphate tends to cling 

to sediments. (a) The concentration of nitrate in the 

stream is greater than 2 mg/L (milligrams per liter) 

before the storm begins. Most of the nitrate in the 

stream is derived predominantly from ground-water 

discharge rather than from overland flow. Therefore, 

as overland flow, corresponding to the peak discharge, 

reaches the stream, nitrate that was in the stream 

before the storm is diluted. As the storm passes and 

discharge decreases, the nitrate concentration begins 

to rise again. (b) Phosphates react differently. Before 

the storm, the phosphate concentration is about 

0.13 mg/L. The phosphate concentration peaks when 

the overland flow reaches the stream. Because the 

overland flow washes phosphate-containing 

sediments into the stream, the peaks in discharge 

and concentration coincide. As the discharge 

decreases, the phosphate concentration also 

decreases. (Modified from N. J. Department of 

Environmental Protection, 1979)
83

Phosphate, in contrast, is relatively insoluble

and tends to cling to sediments; therefore, phosphate

concentrations in the stream between storms tend to 

be low. As the streamflow peaks, overland flow containing phosphate-bearing sediment reaches the 

stream and phosphate concentrations in the stream 

rise. As the storm passes and runoff decreases, the 

concentration of phosphate decreases to a betweenstorm minimum. This indicates that phosphate is

derived mainly from the overland-runoff contribution to streamflow. 

Dissolved oxygen in surface water is used by

all forms of aquatic life; therefore, this constituent

typically is measured to assess the “health” of lakes

and streams. Oxygen enters a stream from the atmosphere and from ground-water discharge. The contribution of oxygen from ground-water discharge is

significant, however, only in areas where ground 

water is a large component of streamflow, such as in

the Coastal Plain or glacial deposits. The concentration of dissolved oxygen is inversely related to water 

temperature (Box E): as water temperature rises, the

dissolved-oxygen concentration falls, and as water 

temperature falls, the dissolved-oxygen concentration rises (Reed and others, 1998). Photosynthesis is

the primary process affecting the dissolved-oxygen/

temperature relation; water clarity and strength and 

duration of sunlight, in turn, affect the rate of photosynthesis (Reed and others, 1998). Dissolved-oxygen concentrations fluctuate with water temperature 

seasonally as well as diurnally (daily).

The USGS, in cooperation with the NJDEP,

collects and analyzes surface-water samples 

throughout the State of New Jersey on a regular

basis. Surface-water-quality records for New Jersey

streams extend back to about 1923, and current data

are now published annually in the USGS waterresources data report (Reed and others, 1998). In

1998, the surface-water-sampling network was

expanded. The network was modified in order to

increase the area represented and to improve data

coverage by moving some of the sampling sites from 

year to year. Surface-water samples are collected at

more than 100 sites throughout the five water regions 

(fig. 30). The site locations are selected to serve a

variety of purposes. Some sites in each water region

are selected to represent the surface water that is

associated with the major land use in the water 

region. Others are selected to represent the quality of 

water downstream from large tributaries. Still others

are located in pristine areas of a water region to be

used as “background” or “reference” sites. Sites 

located on the Delaware River provide data that support the efforts of the Delaware River Basin Commission. Finally, some sites are selected randomly;

these sites vary from year to year to maximize coverage of streams in each water region. These are special sites that can be located in a problem area or area

of special interest to provide concentrated data coverage.

Water-column (water surface to stream bottom) samples are collected at each site four times per 

year during both growing and non-growing seasons. 

The water column constituents and properties measured depend on the site type but may include nutrients, biological oxygen demand, major ions plus

boron, organic carbon, suspended sediment, field 

parameters (pH, water temperature, specific conductance, dissolved-oxygen concentration, and turbidity), pesticides, trace elements, and volatile organic 

compounds. The stream discharge and chemical

quality of stream-bottom sediments also are measured. These data can be used by planners and scientists to identify and monitor problem areas, provide 

background data before implementing changes to an

area, and determine the effects of land use and other

changes on surface-water quality.
84

Figure E-3. The concentration of dissolved oxygen in 

surface water is controlled by temperature and has both 

a seasonal and a daily cycle. Cold water can hold more 

dissolved oxygen than warm water. In winter and early 

spring, when the water temperature is low, the dissolvedoxygen concentration is high. In summer and fall, when 

the water temperature is high, the dissolved-oxygen 

concentration is low.

Figure E-4. Photosynthesis by algae in the stream 

produces oxygen and plays a large part in the dissolvedoxygen/temperature relation. Photosynthesis is affected 

by water clarity and the strength and duration of sunlight 

(Reed and others, 1998). In the diurnal (daily) cycle, 

during daylight hours photosynthesis produces oxygen, 

causing the dissolved-oxygen concentration to rise. 

Water temperature also rises during daylight hours. At 

night, the algae consume oxygen, causing the dissolvedoxygen concentration to fall. Water temperature also 

falls during the night. Although the effects of photosynthesis override the dissolved-oxygen/temperature 

relation in the diurnal cycle, the general trend of this 

relation can still be seen over longer periods.

31 1 2 3 6 7 8 10 6

13

7

8

9

10

11

12

COCNENTRATION OF DISSOLVED OXYGEN, 

IN MILLIGRAMS PER LITER

6

14

7

8

9

10

11

12

13

WATER TEMPERATURE, IN DEGREES CELSIUS

Dissolved oxygen

Water temperature

JAN. FEB. APR. JUNE JULY OCT. NOV.

5

14

6

7

8

9

10

11

12

13

CONCENTRATION OF DISSOLVED OXYGEN, 

IN MILLIGRAMS PER LITER

0

30

5

10

15

20

25

WATER TEMPERATURE, IN DEGREES CELSIUS

Dissolved oxygen

Water temperature 

No data SEASONAL VARIATION

MEAN DAILY DISSOLVED-OXYGEN CONCENTRATION AND 

WATER TEMPERATURE, PASSAIC RIVER BELOW 

POMPTON RIVER AT TWO BRIDGES, N. J., JANUARYDECEMBER 1998

HOURLY DISSOLVED-OXYGEN CONCENTRATION AND 

WATER TEMPERATURE, PASSAIC RIVER BELOW 

POMPTON RIVER AT TWO BRIDGES, N. J., OCTOBER 31-

NOVEMBER 10, 1998

DIURNAL VARIATION

As water temperature decreases,

dissolved-oxygen concentration

increases 

MAR. MAY AUG. SEPT.

4 5 9

OCT. NOV.

DEC.

No data

Clean

zone

Decomposition

zone

Septic

zone

Recovery

zone

Clean

zone

Contaminant

CONCENTRATION OF DISSOLVED OXYGEN

OR OXIDIZABLE CONTAMINANT

Contaminant

added

Dissolved oxygen

TIME, OR DISTANCE DOWNSTREAM

(Modified from Manahan, 1997; published with permission)

130 120 110 100 90 80 70 60 50 40 30

10

8

6

4

2

0

CONCENTRATION OF DISSOLVED OXYGEN, 

IN MILLIGRAMS PER LITER

MILES TO ATLANTIC OCEAN

140

Trenton, N.J.

+ +

+

+

+ + +

+

+

+

+

+

+ +

+ + 1994

1980

1990

1970

(Modified from Delaware River Basin Commission, 1998)

+

Bristol, N.J.

Philadelphia,Pa.

Wilmington,Del.

Figure E-1. Model of the oxygen-sag curve in a stream. 

In a healthy, uncontaminated stream, the bacteria level is 

low and the concentration of dissolved oxygen is high. 

When a contaminant is added, the dissolved oxygen 

begins to diminish as the bacteria decompose the 

contaminant. Bacteria reproduce and flourish and 

continue to consume dissolved oxygen. The "septic 

zone" is characterized by a high bacteria level and low 

dissolved-oxygen concentration. When the contaminant 

is depleted, recovery can begin. Dissolved-oxygen 

concentrations begin to recover and bacteria levels 

decrease.

E

Dissolved oxygen

Figure E-2. Actual oxygen-sag curve for the Delaware 

River during 1970-94. Dissolved-oxygen concentrations 

measured during the 1970's and 1980's decreased 

between miles 115 and 90 as contaminants were discharged into the river. In recent years, as a result of 

cleanup efforts and the upgraded level of treatment in 

the wastewater-treatment plants, the dissolved-oxygen 

concentrations no longer drop so dramatically in this 

reach of the river (Richard Albert, Delaware River Basin 

Commission, oral commun., 1999).

84
85

Tidal areas, Cattus Island, Ocean County, New 

Jersey. (Photograph by Robert Nicholson)

The NJDEP Bureau of Marine Water Monitoring analyzes water-column samples from approximately 300 sites in the tidal parts of rivers and in

estuaries to monitor the ecological health of New 

Jersey’s coastal waters (fig. 30). Constituents and 

properties measured at these sites include dissolved 

oxygen, salinity, nitrogen, phosphorus, Secchi disk

depth (a turbidity measurement), temperature, suspended solids, and chlorophyll a. Samples are collected four times per year during both growing and 

non-growing seasons. (See N.J. Department of Environmental Protection, 1998c.) These data are used to

assess the quality of water in the estuaries and tidal 

parts of the rivers as well as to supplement data on 

bacteria concentrations for determining shellfishharvesting safety.

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Base from U.S. Geological Survey

digital line graph files, 1:24,000

NEW YORK

Figure 30. Surface-water-quality sampling sites and 

estuarine and tidal river monitoring sites active in 

New Jersey in 1998. Surface-water-quality data allow 

planners and scientists to locate problem areas, 

evaluate current conditions before implementing 

change, and calculate the effects of change. The N.J. 

Department of Environmental Protection analyzes 

water samples from the estuaries and tidal portions of

rivers to monitor the ecological health of the coastal 

waters.

Watershed Management 

Area boundary--From 

N.J. Department of 

Environmental 

Protection, 1:24,000 

digital line graph file, 

1997

Estuarine or tidal river monitoring sites

(Locations from digital data, N.J. 

Department of Environmental 

Protection, 1998)

SAMPLING SITES--

EXPLANATION

Surface-water-quality site, 1998
86

Biological data

In 1992, the NJDEP Bureau of Freshwater and

Biological Monitoring re-established the Ambient

Biomonitoring Network (AMNET) to sample and 

analyze benthic (bottom-dwelling) macroinvertebrates in the non-tidal streams of New Jersey. (Previous AMNET sampling was conducted at 18 stations

in 1988 (N.J. Department of Environmental Protection, 1998d).) Macroinvertebrates, animals without 

spinal columns, can be seen with the naked eye and

live in aquatic habitats. Common freshwater benthic 

macroinvertebrates are aquatic insects, worms,

snails, crayfish, and clams. Macroinvertebrates were

collected at more than 700 sites during 1992-96 (fig. 

31). These sites are located throughout the State, in

each of the five water regions. Samples are collected 

in one water region per year on a 5-year rotational

basis. Thus far, all five water regions have been monitored once. AMNET was established because the 

benthic macroinvertebrates found in the streams are

sensitive to environmental changes and are a good 

indicator of the water quality. Data on benthic macroinvertebrates are compared to similar data collected at a “reference site”--a minimally disturbed

site--and each is rated as either severely imparied,

moderately impaired, or nonimpaired depending on 

the characteristics of the benthic macroinvertebrate 

communities that were counted at the sampling site. 

Major factors that affect the benthic macroinvertebrate communities are land use upstream from the 

sampling site and the amount of municipal-waste 

effluent in the stream (Kennen, 1998). Sites in urban 

areas with high levels of municipal-waste effluent

typically receive ratings of severely impaired. Sampling sites in forested areas or downstream from forested areas typically are judged to be nonimpaired.

These ratings can help planners and officials decide

where to permit discharge of wastewaters to a

stream, evaluate the effects of development on the 

aquatic environment, and determine where remediation or additional monitoring may be necessary 

(Kennen, 1998; N.J. Department of Environmental 

Protection, 1996a). 

In 1996, the NJDEP Bureau of Marine Water 

Monitoring began an Ambient Biomonitoring Network in the fresh- and saltwater tidal zones of New 

Jersey’s streams and rivers. This tidal component of

the AMNET sampling network is referred to as

BAYNET. BAYNET sampling was initiated at 15

sites on seven major streams in the Atlantic Coastal

water region (fig. 31) because of the ecological, economic, and recreational importance of these streams 

in New Jersey (N.J. Department of Environmental

Protection, 1998a).

Collecting macroinvertebrates in the Rockaway River 

at Boonton, New Jersey. (Photograph by Mark Ayers)
87

“...benthic macroinvertebrates 

found in the streams are

sensitive to environmental

changes and are a good

indicator of the water quality.”

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digital line graph files, 1:24,000

NEW YORK

Watershed Management 

Area boundary--From 

N.J. Department of 

Environmental Protection, 

1:24,000 digital line graph 

file, 1997

AMBIENT BIOMONITORING NETWORK

SAMPLING LOCATION--From digital

data, N.J. Department of Environmental 

Protection, 1998

EXPLANATION

Figure 31. N.J. Department of Environmental 

Protection Ambient Biomonitoring Network sites in 

New Jersey during 1992-96. This network is operated 

to monitor the aquatic life in the streams and to 

evaluate the effects of streamwater quality on the 

health of aquatic communities. Data collected at 

these sites help planners and officials decide where 

to permit contaminant discharges, evaluate the 

effects of development on the environment, and 

determine where further remediation or monitoring 

may be needed.

Fresh and saltwater tidal zones 

(BAYNET)

Non-tidal rivers (AMNET)
88

Ground-water quality

Because about 50 percent of all drinking water 

in New Jersey is derived from ground-water sources,

predominantly from public-supply wells and a 

smaller percentage from domestic wells (U.S. Geological Survey, 1986b), ground-water quality is of

great concern. Both natural and human-derived contaminants are commonly found in ground water and 

can include nitrates, bacteria, iron, sulfur, methane

gas, radium, pesticides, and petroleum and other

organic compounds (Waller, 1994). Naturally occurring contaminants are present in the rocks and sediments. As ground water flows through sediments, 

metals such as iron and manganese are dissolved and 

may later be found in high concentrations in the

water. Industrial discharges, urban activities, agriculture, ground-water pumpage, and disposal of waste

all can affect ground-water quality. Contaminants

from leaking fuel tanks or fuel or toxic chemical 

spills may enter the ground water and contaminate

the aquifer. Pesticides and fertilizers applied to

lawns and crops can accumulate and migrate to the 

water table. Bacterial contamination from septictank effluent is one of the most common water-quality problems in rural areas (Waller, 1994). 

The physical properties of an aquifer, such as

thickness, rock or sediment type, and location, play 

a large part in determining whether contaminants

from the land surface will reach the ground water.

The risk of contamination is greater for unconfined 

(water-table) aquifers than for confined aquifers

because they usually are nearer to land surface and 

lack an overlying confining layer to impede the 

movement of contaminants. Because ground water

moves slowly in the subsurface and many contaminants sorb to the sediments, restoration of a contaminated aquifer is difficult and may require years, 

decades, centuries, or even millennia.

Some of the contaminants commonly detected

in drinking-water supplies derived from ground 

water in New Jersey and their potential health effects

are listed in table 6. Inorganic and organic chemicals, 

microbiological and radiological contaminants, and 

physical characteristics of ground water are listed. 

The USGS, in cooperation with the NJDEP,

has been collecting and analyzing ground-water 

Sampling ground water from a domestic well. 

(Photograph by Rick Clawges)

samples since the late 1800’s, and a formal monitoring program to investigate saltwater intrusion began 

in 1923 (U.S. Geological Survey, 1986b). In the 

early 1960’s, the USGS began sampling approximately 20 wells per year, mostly in the Coastal Plain,

to measure concentrations of inorganic ions and 

compounds. In the early 1980’s, an ambient groundwater-quality network was established to monitor 

water quality in all aquifers throughout the State. 

The few constituents for which samples were analyzed included various organic compounds and trace

elements. Current (2000) plans for the ambient 

ground-water-quality network are to increase the 

number of wells sampled per year in all five water 

regions. The focus of the network will be to sample

water in shallow wells that are completed in the

unconfined aquifer to improve understanding of the

ground-water/surface-water interaction. Samples 

will be analyzed for concentrations of nutrients, 

major ions, trace elements, volatile organic compounds, and radionuclides. 

The USGS also conducts studies on a regional, 

county, township, and site-specific basis to investigate ground-water-quality problems. In the 1970’s, a

typical water-quality analysis included measuring 

concentrations of chloride, sulfate, major ions, and 

some trace elements, mostly for regional and countywide studies. During the 1980’s, laboratory instrumentation became more precise, analytical detection

levels were lowered, sampling methods improved, 

and the knowledge of which constituents were likely 

to be present in the ground water increased. Samples
8

9

Table 6. Contaminants commonly detected in drinking water derived from ground-water sources

Contaminant Sources to ground water Potential health and other ef

Inorganic contaminants

Aluminum Occurs naturally in some rocks and drainage from mines. Can precipitate out of water after treatment, causing inc

water.

Antimony Enters environment from natural weathering, industrial production, municipal waste disposal, and manufacturing of flame retardants, ceramics, glass, batteries, fireworks, and 

explosives.

Decreases longevity, alters blood levels of glucose and cexposed at high levels over their lifetime.

Arsenic Enters environment from natural processes, industrial activities, pesticides, and industrial waste, smelting of copper, lead, and zinc ore. Causes acute and chronic toxicity, liver and kidney dam

bin. Possible carcinogen.

Asbestos Occurs naturally; also from corroded asbestos cemented pipes, production of textiles,

plastics, cements, flood tiles, paper products, paint, caulking, and fire-retardant material.

Causes lung tumors in laboratory animals during inhala

Barium Occurs naturally in some limestones, sandstones, and soils in the eastern United States. Can cause a variety of cardiac, gastrointestinal, and neu

with hypertension and cardiotoxicity in animals.

Beryllium Occurs naturally in soils, ground water, and surface water. Often used in electrical industry equipment and components, nuclear power and space industry. Enters the environment from mining operations, processing plants, and improper waste disposal. Causes acute and chronic toxicity; can cause damage to 

cinogen.

Cadmium Found in low concentrations in rocks, coal, and petroleum and enters the ground and

surface water when dissolved by acidic waters. May enter the environment from industrial discharge, mining waste, metal plating, water pipes, batteries, paints and pigments,plastic stabilizers, and landfill leachate.

Replaces zinc biochemically in the body and causes higney damage, and anemia. Destroys testicular tissue and biota.

Chloride May be associated with the presence of sodium in drinking water when present in high 

concentrations. Often from saltwater intrusion, mineral dissolution, industrial and domestic waste.

Deteriorates plumbing, water heaters, and municipal waels. Above secondary maximum contaminant level, tast

Chromium Enters environment from old mining operations runoff and leaching into ground water,

fossil-fuel combustion, cement-plant emissions, mineral leaching, and waste incineration. Used in metal plating and as a cooling-tower water additive.

Chromium III is a nutritionally essential element. ChromChromium III and causes liver and kidney damage, intedamage, dermatitis, and ulcers on the skin at high conce

Copper Enters environment from metal plating, industrial and domestic waste, mining, and mineral leaching. Can cause stomach and intestinal distress, liver and kidn

doses. Imparts an adverse taste and significant staining trace element but toxic to plants and algae at moderate l

Cyanide Often used in electroplating, steel processing, plastics, synthetic fabrics, and fertilizer

production; also from improper waste disposal.

Poisoning is the result of damage to spleen, brain, and l

Dissolvedsolids

Occur naturally but also enters environment from man-made sources such as landfill leachate, feedlots, or sewage. A measure of the dissolved “salts” or minerals in the

water. May also include some dissolved organic compounds.

May have an influence on the acceptability of water in gpresence of excess concentrations of specific substanceDrinking Act, which would make water objectionable. Hsolids shorten the life of hot water heaters.

Fluoride Occurs naturally or as an additive to municipal water supplies; widely used in industry. Decreases incidence of tooth decay but high levels can s

pling bone disorder (calcification of the bones and joint

Hardness Result of metallic ions dissolved in the water; reported as concentration of calcium carbonate. Calcium carbonate is derived from dissolved limestone or discharges from operating or abandoned mines. Decreases the lather formation of soap and increases sc

ers and low-pressure boilers at high levels.

Iron Occurs naturally as a mineral from sediment and rocks or from mining, industrial waste,

and corroding metal.

Imparts a bitter astringent taste to water and a brownish plumbing fixtures.

Lead Enters environment from industry, mining, plumbing, gasoline, coal, and as a water 

additive.

Affects red blood cell chemistry; delays normal physicababies and young children. Causes slight deficits in attenin children. Can cause slight increase in blood pressure ogen.

Manganese Occurs naturally as a mineral from sediment and rocks or from mining and industrial

waste.

Causes aesthetic and economic damage, and imparts brotaste of water, and causes dark brown or black stains on non-toxic to animals but toxic to plants at high levels.
90

Mercury Occurs as an inorganic salt and as organic mercury compounds. Enters the environment

from industrial waste, mining, pesticides, coal, electrical equipment (batteries, lamps,switches), smelting, and fossil-fuel combustion.

Causes acute and chronic toxicity. Targets the kidneys adisorders.

Nickel Occurs naturally in soils, ground water, and surface water. Often used in electroplating,

stainless steel and alloy products, mining, and refining.

Damages the heart and liver of laboratory animals expolifetime.

Nitrate (as nitrogen)

Occurs naturally in mineral deposits, soils, seawater, freshwater systems, the atmosphere, and biota. More stable form of combined nitrogen in oxygenated water. Found inthe highest levels in ground water under extensively developed areas. Enters the environment from fertilizer, feedlots, and sewage.

Toxicity results from the body’s natural breakdown of n

baby disease,” or methemoglobinemia, which threatens 

blood.

Nitrite(combinednitrate/nitrite)

Enters environment from fertilizer, sewage, and human or farm-animal waste. Toxicity results from the body’s natural breakdown of n

baby disease,” or methemoglobinemia, which threatens 

blood.

Selenium Enters environment from naturally occurring geologic sources, sulfur, and coal. Causes acute and chronic toxic effects in animals--”blin

ally essential element at low doses but toxic at high dos

Silver Enters environment from ore mining and processing, product fabrication, and disposal.

Often used in photography, electric and electronic equipment, sterling and electroplating, alloy, and solder. Because of great economic value of silver, recovery practices are typically used to minimize loss.

Can cause argyria, a blue-gray coloration of the skin, morgans in humans and animals with chronic exposure.

Sodium Derived geologically from leaching of surface and underground deposits of salt and 

decomposition of various minerals. Human activities contribute through de-icing andwashing products.

Can be a health risk factor for those individuals on a low

Sulfate Elevated concentrations may result from saltwater intrusion, mineral dissolution, and 

domestic or industrial waste.

Forms hard scales on boilers and heat exchangers; can ca laxative effect in high doses.

Thallium Enters environment from soils; used in electronics, pharmaceuticals manufacturing,

glass, and alloys.

Damages kidneys, liver, brain, and intestines in laboratodoses over their lifetime.

Zinc Found naturally in water, most frequently in areas where it is mined. Enters environment

from industrial waste, metal plating, and plumbing, and is a major component of sludge.

Aids in the healing of wounds. Causes no ill health effeImparts an undesirable taste to water. Toxic to plants at 

Organic contaminants

Volatileorganic compounds

Enter environment when used to make plastics, dyes, rubbers, polishes, solvents, crudeoil, insecticides, inks, varnishes, paints, disinfectants, gasoline products, pharmaceuticals, preservatives, spot removers, paint removers, degreasers, and many more.

Can cause cancer and liver damage, anemia, gastrointesblurred vision, exhaustion, weight loss, damage to the ntract irritation.

Pesticides Enter environment as herbicides, insecticides, fungicides, rodenticides, and algicides. Cause poisoning, headaches, dizziness, gastrointestinal 

ness, and cancer. Destroys nervous system, thyroid, repneys.

Plasticizers, chlorinated solvents, benzo[a]pyrene, and dioxin

Used as sealants, linings, solvents, pesticides, plasticizers, components of gasoline, disinfectant, and wood preservative. Enters the environment from improper waste disposal,leaching runoff, leaking storage tank, and industrial runoff.

Cause cancer. Damages nervous and reproductive syste

Foamingagents(ABS/LAS)1

Indicative of undesirable contaminants from questionable sources like infiltration fromsewage.

Impart undesirable taste and foaming properties.

1Alkyl-Benzene-Sulfonate and Linear-Alkyl-sulfonate or similar Methylene Blue Reactive Substances contained in synthetic detergents.

Table 6. Contaminants commonly detected in drinking water derived from ground-water sources--Continued

Contaminant Sources to ground water Potential health and other ef
91

Microbiological contaminants

Coliformbacteria

Occur naturally in the environment from soils and plants and in the intestines of humansand other warm-blooded animals. Used as an indicator for the presence of pathogenicbacteria, viruses, and parasites from domestic sewage, animal waste, or plant or soilmaterial.

Bacteria, viruses, and parasites can cause polio, cholerainfectious hepatitis.

Radiological contaminants

Gross alpha-particle activity A category of radioactive isotopes. Occurs from either natural or man-made sources including weapons, nuclear reactors, atomic energy for power, medical treatment and 

diagnosis, mining radioactive material, and naturally occurring radioactive geologic formations. Primary concern is natural sources, which are ubiquitous in the environment(Durrance, 1986); secondary concern is man-made sources.

Damages tissues and destroys bone marrow.

Combined radium-226 andradium-228

Enters environment from natural and man-made sources. Historical industrial-wastesites are the main man-made source.

Causes cancer by concentrating in the bone and skeletal 

Beta-particle and photonradioactivity

A category of radioactive isotopes from either natural or man-made sources including weapons, nuclear reactors, atomic energy for power, medical treatment and diagnosis,mining radioactive material, and naturally occurring radioactive geologic formations.Primary concern is man-made sources because of widespread use (Durrance, 1986); secondary concern is natural sources.

Damages tissues and destroys bone marrow.

Physical characteristics

Turbidity Caused by the presence of suspended matter such as clay, silt, and fine particles of

organic and inorganic matter, plankton, and other microscopic organisms. A measure of how much light can filter through the water sample.

Objectionable for aesthetic reasons. Indicative of clay oin drinking water. May not adversely affect health but mtreatment. Following rainfall, variations in ground-wateof surface contamination.

Color Can be caused by decaying leaves, plants, organic matter, copper, iron, and manganese,

which may be objectionable. Indicative of large amounts of organic chemicals, inadequate treatment, and high disinfection demand. Potential for production of excess amounts of disinfection byproducts.

Suggests that treatment is needed. No health concerns. A

pH Indicates, by numerical expression, the degree to which water is alkaline or acidic. Represented on a scale of 0-14 where 0 is the most acidic, 14 is the most alkaline, and 7 is

neutral.

High pH causes a bitter taste; water pipes and water-usindepresses the effectiveness of the disinfection of chlorinadditional chlorine when pH is high. Low-pH water wilother substances.

Odor Certain odors may be indicative of organic or non-organic contaminants that originate 

from municipal or industrial waste discharges or from natural sources.

Taste Some substances such as certain organic salts produce a taste without an odor and can be 

evaluated by a taste test. Many other sensations ascribed to the sense of taste actually are odors, even though the sensation is not noticed until the material is taken into the mouth.

Table 6. Contaminants commonly detected in drinking water derived from ground-water sources--Continued

Contaminant Sources to ground water Potential health and other ef
92

Rural Salem County, New Jersey.

(Photograph by Melissa Storck)

commonly were analyzed for volatile organic compounds, radionuclides, and pesticides as well as

other organic compounds, inorganic compounds, 

and trace elements. Water-quality data for more than

2,000 wells in New Jersey are available in the USGS 

data base (fig. 32). Because the number of analytes

(constituents measured in a water sample) has 

increased with time, more water-quality data generally are available for recently collected samples than 

for samples collected several years or decades ago.

Nitrate concentrations in samples from more

than 2,000 wells throughout the State are shown in

figure 33. Nitrate commonly occurs in ground water

in concentrations greater than the USEPA MCL of

10 mg/L (milligrams per liter) as a result of human 

activities. Nitrate is very mobile and dissolves easily

in water. Sources include fertilizers, septic systems,

and animal waste. Wells that contain high concentrations of nitrate are found predominantly in agricultural and urban areas. Shallow wells are more

vulnerable to nitrate contamination than are deeper

wells. Parts of New Jersey in which nitrate concentrations in ground water are elevated include Cumberland and Salem Counties, where agriculture is the 

dominant land use. Nitrate concentrations also are 

elevated along the Delaware River near Camden and

where many of the Coastal Plain aquifers crop out at

the land surface. Ground water in older residential 

areas also tends to contain elevated nitrate concentrations. Nitrate concentrations tend to be low in

undeveloped and nonagricultural areas and in wells 

that are completed in confined aquifers. Dilution of

young, nitrate-contaminated ground water with

older, uncontaminated ground water also can

account for low nitrate concentrations. This situation 

typically occurs in northern New Jersey, where wells 

are drilled in consolidated rock and commonly are 

open holes that may extend for hundreds of feet, 

allowing the younger and older ground water to mix. 

Figure 32. Ground-water-quality and saltwatermonitoring sites in New Jersey. The ground-waterquality sites represent all wells for which water-quality 

data are stored in the U.S. Geological Survey data 

base. Samples from newer wells typically were 

analyzed for a greater number of constituents than 

samples from older wells. The saltwater-monitoring

network was established in the 1940’s to monitor the 

movement of saline water, which can affect the 

potability of the ground-water supply.

Watershed Management 

Area boundary--From 

N.J. Department of 

Environmental 

Protection, 1:24,000 

digital line graph file, 

1997

Ground-water-quality site

Saltwater-monitoring site

SAMPLING SITES--

EXPLANATION

(Locations from unpublished data accessed 

Sept. 8, 1998, on the World Wide Web at URL

http://njusgs.gov/gw/gw-qw_wells.html)

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93

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Figure 33. Nitrate concentrations in water from wells in New Jersey. Nitrate in ground

water is a potential problem because it is easily dissolved, is very mobile at certain

concentrations, and can be dangerous to the health of infants. High nitrate concentrations

are typically associated with agriculture and urban development. The risk of nitrate 

contamination is greater for unconfined aquifers than for confined aquifers because 

they are not protected by a confining unit from contaminants originating at land surface.

Watershed Management 

Area boundary--From N.J. 

Department of Environmental 

Protection, 1:24,000 digital 

line graph file, 1997

Less than 1

1-2.9

3-9.9

10 or greater

EXPLANATION

NITRATE CONCENTRATION, 

IN MILLIGRAMS PER LITER--

Locations from unpublished data 

accessed Sept. 8, 1998, on the 

World Wide Web at URL

http://nj.usgs.gov/qw-cgi/nitrate.pl
94

Saltwater monitoring

Chloride concentrations affect the potability

(suitability as drinking water) of water and also serve

as an accurate index of saltwater intrusion. Saltwater

intrusion is the movement of saltwater into an aquifer that contains freshwater. The freshwater that 

recharges the aquifer is continually discharging to

the ocean. It may discharge to the ocean directly as

ground water or may flow into a stream that ultimately flows to the ocean. Freshwater continually 

mixes with the saltwater in the ocean. The point at

which they meet is called the freshwater/saltwater

interface (fig. 3). If for some reason the amount of

freshwater that usually discharges to the ocean is

reduced--by ground-water withdrawals, for example--the interface moves landward. This phenomenon has been observed in many parts of the New 

Jersey Coastal Plain. 

The USGS collects water samples from wells

located throughout the Coastal Plain of New Jersey

and in the Lower Delaware and Raritan water 

regions to measure chloride concentrations (fig. 32).

This network was established in the 1940’s to monitor saltwater movement. Individual occurrences of 

high chloride concentrations are not definitive proof 

of active saltwater intrusion, however; they may represent a natural, static condition (Jones and DeLuca, 

1998). Therefore, increasing chloride concentrations 

over time, rather than single measurements, must be

documented in order to confirm that saltwater intrusion is occurring.

The change in chloride concentrations over

time in wells in the Atlantic Coastal water region, as

well as historical withdrawals from those wells, are

shown in figure 34. As coastal resort areas were

developed, the need for freshwater increased. Consequently, withdrawals increased until chloride concentrations reached 250 mg/L, the USEPA 

secondary maximum contaminant level for chloride 

(U.S. Environmental Protection Agency, 1990). 

Although withdrawals subsequently were decreased, 

chloride concentrations continued to climb (unpublished data on file at the U.S. Geological Survey

office in West Trenton, N.J.). Possible solutions to

this problem include drilling new wells in parts of

the aquifer that contain lower chloride concentrations, building a plant that removes the chloride from 

the water (desalinization), or reducing withdrawals 

and importing freshwater from neighboring areas.

Development along the New Jersey coast, Seaside 

Heights. (File photograph, U.S. Geological Survey,

West Trenton, New Jersey)
9

5

1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 

0

1,000

200400600800

Figure 34. Annual withdrawals from the Kirkwood-Cohansey aquifer system and late summer chloride concentrations in water froselected wells at (a) Point Pleasant Beach and (b) Seaside Heights, New Jersey, 1918-95. Chloride concentrations increased witground-water withdrawals, indicating saltwater intrusion. In some years, chloride concentrations continued to climb despite decreased withdrawals. (Unpublished data on file at the U.S. Geological Survey office in West Trenton, N.J.; numbers inparentheses are U.S. Geological Survey well numbers)

1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 

0

1,000

200400600800

CHLORIDE CONCENTRATION, IN MILLIGRAMS PER LITER Annual withdrawals Well 1R (29-538) Well 3 (29-539) Well 5 (29-617)

Point Pleasant Beach Water Department wells

Seaside Heights Water Department wells

a

b

Annual withdrawalsWell 9 (29-521)Well 10 (29-523)Well 11 (29-579)

Well 12 (29-807)Well 13 (29-1106)
96

Potential Contaminant Sources

New Jersey Pollutant Discharge

Elimination System (NJPDES) Sites

The NJDEP’s New Jersey Pollutant Discharge 

Elimination System (NJPDES) program, started in

1981, monitors and regulates the amount of waste 

and contaminants that is discharged to surface and 

ground water. Permits are granted for industrial,

commercial, and municipal water users that discharge to surface- or ground-water sources. Groundwater discharges are divided into two major programs: remedial discharges and operational discharges. Remedial discharges include the reinjection 

of ground water that has been treated in cleanup programs. Operational discharges include effluent from

major septic systems, land applications that include

surface impoundments and infiltration/percolation

lagoons, injection wells, resource-recovery uses of

sludge and compost, and landfills for both hazardous

and nonhazardous material (N.J. Department of

Environmental Protection, 1996b). Locations of the 

NJPDES permitted discharges in the State are shown 

in figure 35. NJPDES sites are divided into major,

minor, non-contact cooling, and petroleum-cleanup

sites. Major industrial sites are defined as sites that

score 80 or more points on a USEPA guideline point

system that measures characteristics of industrial

facilities; minor sites score less than 80 points. A 

major municipal facility is defined as a site with flow 

of 1.0 Mgal/d (million gallons per day) or greater; a 

minor municipal facility is a site where flow is less

than 1.0 Mgal/d. Non-contact cooling sites typically 

use water for heat exchange. Petroleum-cleanup sites 

are generally located at gas or service stations. (See

N.J. Department of Environmental Protection,

1997b.) Discharge sites are concentrated in the more 

developed parts of the State. All permittees are

required to perform routine water-quality monitoring. These data, together with the permitting process,

provide the information and control necessary to

protect the quality of water in a watershed by identifying point sources of contaminants and controlling

the amount that can be discharged.

Industrial site, New Jersey. (Photograph by Rick 

Clawges)
97

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97

Figure 35. New Jersey Pollutant Discharge Elimination 

System (NJPDES) surface-water-discharge sites in 

New Jersey. NJPDES discharge permits are issued to 

industries, municipalities, or community users that 

discharge to ground- or surface-water sources. Routine 

water-quality monitoring of point sources of contamination 

is required in order to protect and restore the quality 

of water in New Jersey.

Watershed Management 

Area boundary--From 

N.J. Department of 

Environmental Protection, 

1:24,000 digital line graph 

file, 1997

Location of NJPDES surface-waterdischarge sites--From digital data N.J. 

Department of Environmental Protection,

1998

EXPLANATION

Major site

Minor site

Non-contact cooling site

Petroleum cleanup site 
98

Landfills and hazardous-waste sites

Between 10,000 and 15,000 companies in

New Jersey engage in the manufacture of chemical

and petrochemical products (U.S. Geological Survey, 1986b); many other industries are represented as

well. The use, storage, and transport of hazardous

chemicals is common throughout the State (U.S. 

Geological Survey, 1986b). Common causes or 

sources of contamination of ground water and surface water are chemical spills, improper use and disposal of chemicals, improper disposal of waste,

illegal discharges from industrial and other facilities, 

leachate from landfills, and leaks from storage tanks,

to name a few. The location, status, and, in some

cases, cleanup of landfills and hazardous-waste sites 

are monitored by the NJDEP. GIS coverages of the 

locations of landfills and hazardous-waste sites

throughout the State are available from the NJDEP 

or USGS. Knowing the locations of these sites can 

help in identifying the source of existing or potential

ground- and surface-water contamination problems.

Wastewater discharge to stream. (Photograph by

Eric Vowinkel)
99

Atmospheric Data

Weather stations

Climatological data are collected at 40 stations

throughout the State (fig. 36). Data on precipitation, 

air temperature, soil temperature, snowfall, and

evaporation are collected at various stations by the

National Weather Service and private observers. 

This information is published monthly by the 

National Oceanic and Atmospheric Administration

(NOAA). Climatological data (air temperature, precipitation, and snowfall) are collected at many of the 

stations. At several stations, precipitation data are 

collected hourly.

Climatological data commonly are used in 

ground- and surface-water studies. Precipitation 

amounts and timing of storms are important in studies of streamflow characteristics. They allow investigators to determine the time lag between peak 

rainfall and maximum discharge in the stream. The 

relation between monthly precipitation at the Toms 

River weather station and mean daily discharge at

the Toms River near Toms River, N.J., streamflowgaging station is shown in figure 20. In ground-water

studies, the amount and timing of the precipitation 

can be coupled with a water-level hydrograph to

observe the time lag between peak rainfall and rising 

water levels in the well. Knowing how quickly

recharge reaches the water table, in turn, can allow 

investigators to deduce information about the geologic characteristics of the aquifer material.

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Figure 36. Weather stations and the air-monitoring 

station in New Jersey. Information collected at 

weather stations is used in ground- and surfacewater studies. The amount of precipitation and the 

timing of storms affect streamflow and aquifer 

recharge. Results of air-monitoring are used by 

scientists to determine the effects of contaminants 

in the air on water quality.

Watershed Management 

Area boundary--From 

N.J. Department of 

Environmental Protection, 

1:24,000 digital 

line graph file, 1997

WEATHER STATION COLLECTING--

Locations from National Oceanic and

Atmospheric Administration, 1998

EXPLANATION

Climatological data

Hourly precipitation data

Climatological data and

hourly precipitation data

Air-monitoring station

Data on precipitation, air temperature, soil

temperature, snowfall, and evaporation are

collected at various stations by the National 

Weather Service and private observers.
100

Air-monitoring points

Enormous amounts of man-made and natural

material are added to the air every day (J. Gordon

and M. Nilles, U.S. Geological Survey, unpub. data

titled USGS Tracks Acid Rain, accessed September 

17, 1998, on the World Wide Web at URL http://

btdqs.usgs.gov/acidrain/arfs.html, text format).

Many industries release metallic trace elements such 

as lead, copper, zinc, cadmium, cobalt, and chromium into the atmosphere, and the burning of fossil 

fuels contributes acid-forming substances (Gough 

and others, 1993). As these materials are carried 

away by the wind, they may be caught up in the 

clouds, come in contact with droplets of rain, and fall

back to the ground. The contaminants in this precipitation affect the entire ecosystem, killing plants and 

degrading the quality of the water.

The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) is a 

nationwide network of precipitation-monitoring 

sites at which data on the chemistry of precipitation

have been collected since 1978. These data allow 

trends in atmospheric deposition of contaminants to 

be monitored geographically and over time 

(National Atmospheric Deposition Program/

National Trends Network, 1997). Deposition occurs

not only when it rains and snows, but also when dust 

settles out of the atmosphere during dry periods. Precipitation samples collected weekly at more than 200

sites nationwide are analyzed for pH, sulfate, nitrate, 

ammonia, chloride, calcium, magnesium, potassium,

and sodium. The USGS supports about 80 of these 

sites. This information is useful to scientists and students working on environmental studies, industries, 

government agencies, and anyone involved in environmental regulations, global change, agriculture, 

and air- and water-quality issues. Maps produced 

from these data show the locations of the highest and 

lowest concentrations of constituents and the largest

and smallest deposition. One of these sites, which 

has been in operation since August 1981, is located 

in Washington Crossing, N.J., just north of Trenton 

(fig. 36). This information can be accessed on the

World Wide Web at http://nadp.nrel.colostate.edu/

NADP.

Industrial emissions into the atmosphere along

the lower Delaware River, New Jersey. (File photograph, U.S. Geological Survey, West Trenton,

New Jersey)
101

You can get involved in helping to protect and 

restore the integrity of our water resources. You can 

take action in your own home or in your community. 

Simple actions such as proper lawn care, reducing 

fertilizer applications, using less harmful household 

products, cleaning up after your pet, and maintaining 

your septic system can contribute to environmental

preservation. 

Involvement on the community level might be 

the next step. Many statewide and regional associations that focus on water protection welcome citizen

participation. Call your local government offices to

inquire whether your township has an environmental 

commission or watershed organization. If one is not 

available, you might consider starting your own. 

Awareness activities can be organized to reach out to

the community and provide information about the 

value of the local resources and what can be done to

protect them. Activities such as cleanup days to

remove trash and debris from streams and lakes;

storm-drain stenciling to make the community aware 

that stormwater ends up in the local waterways; recreational events, such as canoeing; volunteering to

speak to classes at local schools about the environment; and monitoring soil erosion or the quality of

water in the streams are all ways to become involved.

Municipal and county government offices may 

already have ongoing programs that need members. 

Call your local environmental commission, board of 

public works, planning board, county soil conservation district, or health department to get involved 

(N.J. Department of Environmental Protection, 

1997d).

HOW TO GET INVOLVED

Canoeing on the Batsto River. (Photograph by 

Robert Nicholson)
102

Environmental groups and watershed associations in New Jersey currently number more than 

60. Some groups are statewide whereas others are 

associated with specific watersheds. The objectives 

of the Watershed Partnership of New Jersey are to

establish a watershed resources network, enhance 

watershed awareness through education, encourage 

community watershed involvement, and strengthen

partnerships between watershed groups. General

information on many of these groups can be

obtained by writing or checking the web site:

Watershed Partnership of New Jersey

New Jersey Audubon Society

600 Route 47 North

Cape May Court House, NJ 08210

Contact: Dale Rosselet

Web site: http://www.wpnj.org 

The NJDEP, Division of Watershed Management, has a leading role in watershed management throughout the State as well as providing

education and outreach information. Programs and 

publications for use in watershed education and outreach activities are available. Call, write, or visit the 

web site:

N.J. Department of Environmental Protection

Division of Watershed Management

P.O. Box 418

Trenton, NJ 08625-0418

Phone: 609-292-2113

Contact: Kyra Hoffman

Web site: http://www.state.nj.us/dep

The USGS, which is part of the U.S.

Department of the Interior, studies water supply,

flooding, droughts, and a variety of other naturalresource issues through cooperative programs with 

State, county, and local governments. Data collected 

on water levels, water quality, water use, and

streamflow can be obtained from the USGS. Data

collected through the various networks and projects

are important in construction projects, environmental studies, and recreation-planning activities. The 

USGS also has a bibliography of reports and educational information available. Call, write, or visit the

web site:

U.S. Geological Survey

810 Bear Tavern Road

Suite 206

West Trenton, NJ 08628

Phone: 609-771-3900

Contact: Eric Evenson, District Chief

Web site for the New Jersey District:

http://wwwnj.er.usgs.gov

Additional web sites for the USGS are: 

USGS home page: http://www.usgs.gov

Water Resources Division:

http://water.usgs.gov

Water education site:

http://water.usgs.gov/droplet

National Mapping Division:

http://mapping.usgs.gov

Geologic Division: http://geology.usgs/gov

Biological Resources Division: 

http://www.nbs.gov

National Water Use:

http://water.usgs.gov/public/watuse

USGS Learning Web:

http://water.usgs.gov/education

LIST OF CONTACTS
103

The Clean Water Book--Lifestyle Choices for 

Water Resources Protection

Available from NJDEP, Division of Watershed

Management, 92 pages

This booklet presents simple ideas on how to

reduce nonpoint-source contamination by the 

things we do every day. Ideas on topics such as 

car, lawn and garden, and pet care; managing your

septic system or underground storage tanks; and 

protecting the shoreline are included. 

Home-A-Syst--An Environmental Risk Assessment 

Guide for the Home

Available from Rutgers Cooperative Extension, 

124 pages

A workbook for self-assessment of your home and

property for contamination and health risks. For

rural and suburban homeowners who want to learn 

how to manage their homes to reduce their effects 

on the natural system. Additional references and

phone numbers are available on each topic covered. Copies can be obtained through Rutgers 

Cooperative Extension, 80 Nichol Avenue, New 

Brunswick, NJ 08901, (732) 932-8264 ext. 10.

Watershed Partnership for New Jersey--New Jersey Watershed Education and Resource Directory 

1998

Available from NJDEP, Division of Watershed

Management, 66 pages

A list of all environmental groups statewide and 

by water region. Names, phone numbers, and a 

brief description of each group are included.

Planning for Clean Water--The Municipal Guide

Available from NJDEP, Division of Watershed

Management, 64 pages

This booklet provides an overview of nonpointsource and stormwater concerns that need to be

addressed during the municipal planning process.

Case studies of success stories in New Jersey are 

included. 

Ground Water and Surface Water--A Single 

Resource

Available through the USGS, U.S. Geological 

Survey Circular 1139, 79 pages

A general educational document explaining

ground water and surface water and the interaction

between the two. Copies can be obtained through 

the USGS, Branch of Information Services, Box 

25286, Denver, CO 80225, (303) 202-4700.

Ground Water and the Rural Homeowner

Available through the USGS, general interest publication, 37 pages

A basic but comprehensive description of ground 

water. Potential problems one may encounter with

ground water and solutions to these problems are 

discussed. Copies can be obtained through the 

USGS, Branch of Information Services, Box 

25286, Denver, CO 80225-0286, (303) 202-4700.

Let it Flow--A Guide to Finding Water Resources

Information in New Jersey

Available through Rutgers Cooperative Extension, 

44 pages

A practical guide to help you find information on 

water resources. Areas of interest that are covered 

include government agencies with waterresources function and (or) responsibility, nonprofit organizations, nonpoint-source contamination, watershed protection and management, 

onsite wastewater disposal and drinking water,

water conservation, and ground water. Copies can 

be obtained by writing Rutgers Cooperative 

Extension, 80 Nichol Ave., New Brunswick, NJ 

08901, (732) 932-8264 ext. 10.

Water Quality Monitoring Networks

Available through the NJDEP, Division of Science 

and Research, 28 pages

This document gives a brief description of many 

of NJDEP’s monitoring programs. Sampling locations are shown, constituents measured are listed,

and a brief history of the program is provided.

SUGGESTED READING
104

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CH2M Hill, Metcalf and Eddy Inc., and NJ First Inc., 

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106

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