Prepared in cooperation with New York State Department of Environmental Conservation

Hydrogeology of the Ramapo River-Woodbury Creek 

Valley-Fill Aquifer System and Adjacent Areas in 

Eastern Orange County, New York

Scientific Investigations Report 2014–5156

U.S. Department of the Interior

U.S. Geological Survey
Cover. Ramapo River valley, looking north from Arden Road, Arden, New York.
Hydrogeology of the Ramapo RiverWoodbury Creek Valley-Fill Aquifer 

System and Adjacent Areas in 

Eastern Orange County, New York

By Paul M. Heisig

Prepared in cooperation with the 

New York State Department of Environmental Conservation

Scientific Investigations Report 2014–5156

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

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Suggested citation:

Heisig, P.M., 2015, Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and adjacent areas 

in eastern Orange County, New York: U.S. Geological Survey Scientific Investigations Report 2014-5156, 23 p., 1 pl., 

http://dx.doi.org/10.3133/sir20145156.

ISSN 2328-0328 (online)
iii

Acknowledgments

The author expresses sincere thanks to those landowners, businesses, and institutions that 

granted access for horizontal-to-vertical (H/V) passive seismic surveys. Bill McClennan, Water 

and Wastewater Treatment Superintendent, Town of Woodbury, and John Karl, Superintendent 

of Village of Harriman Department of Public Works, shared local knowledge, well information, 

and also facilitated site access for seismic surveys. Steven Gagnon, Senior Public Health 

Engineer at the Orange County Department of Health, provided data for public-supply wells. 

David Church, Commissioner, and Kelly Dobbins, Orange County Planning Department, 

provided information and support in the early stages of the project. Thanks are extended to 

Scott Stanford, New Jersey Geological Survey, and Allan Randall, U.S. Geological Survey, for 

insightful reviews and follow-up discussions. 

v

Contents

Acknowledgments........................................................................................................................................iii

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

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

Purpose and Scope ..............................................................................................................................2

Previous Investigations........................................................................................................................2

Bedrock Geology...................................................................................................................................2

Glacial Geology .....................................................................................................................................5

 Overview of Water-Resource Use ....................................................................................................5

Data Sources and Methods ................................................................................................................7

Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System..............................7

South Section ........................................................................................................................................7

Setting ...........................................................................................................................................7

Valley-Fill Deposits and Water-Resource Potential...............................................................8

Central Section......................................................................................................................................8

Setting ...........................................................................................................................................9

Valley-Fill Deposits and Water-Resource Potential...............................................................9

North Section.......................................................................................................................................10

Setting .........................................................................................................................................10

Valley-Fill Deposits and Water-Resource Potential.............................................................10

Groundwater Circulation ............................................................................................................................11

Water-Resource Considerations for the Valley-Fill Aquifer System...................................................12

Summary........................................................................................................................................................13

References Cited..........................................................................................................................................13

Appendix 1. Well Data for the Ramapo River-Woodbury Creek Valley and Adjacent Uplands,

Eastern Orange County, New York (http://dx.doi.org/10.3133/sir20145156)...........................22

Appendix 2. North-south longitudinal section along Ramapo River-Woodbury Creek valleys 

showing elevations of flood plains, terraces, and other valley-bottom glacial features...23

Plate

1. Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and 

adjacent areas in eastern Orange County, New York (http://dx.doi.org/10.3133/sir20145156)

Figures

1A. Map showing topography, political boundaries, major roads, and hydrography of the 

Ramapo River-Woodbury Creek study area in eastern Orange County, New York ..................3

1B. Map showing generalized bedrock geology, mapped and inferred faults, and lineaments 

identified from light detection and ranging (lidar) imagery of the Ramapo River-Woodbury 

Creek study area in eastern Orange County, New York .................................................................4

2. Map showing the south, central, and north sections of the study area, the

stratified-drift aquifer extent, aquifer areas of thick (10 feet or greater) saturated

sand and gravel deposits, and the extent of thick till, Orange County, New York .............6
vi

3. Hydrogeologic section A–A’ at Arden, Orange County, New York.....................................16

4. Hydrogeologic section B–B’ at Harriman, Orange County, New York ..............................18

5. Hydrogeologic section C–C’ at Woodbury, Orange County, New York..............................19

6. Hydrogeologic section D–D’ at Mountainville, Orange County, New York .......................20

Conversion Factors

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Flow rate

foot per minute (ft/min) 0.3048 meter per minute (m/min)

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

cubic foot per second (ft3

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

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

Hydraulic conductivity

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

Hydraulic gradient

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km)

Datum

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Elevation, as used in this report, refers to distance above the vertical datum.

Abbreviations

H/V horizontal-to-vertical

lidar light detection and ranging 

NWIS National Water Information System

NYSDEC New York State Department of Environmental Conservation

USGS U.S. Geological Survey
Hydrogeology of the Ramapo River-Woodbury Creek 

Valley-Fill Aquifer System and Adjacent Areas in Eastern 

Orange County, New York

By Paul M. Heisig

Abstract

The hydrogeology of the valley-fill aquifer system and 

surrounding watershed areas was investigated within a 23-mile 

long, fault-controlled valley in eastern Orange County, New 

York. Glacial deposits form a divide within the valley that 

is drained to the north by Woodbury Creek and is drained 

to the south by the Ramapo River. Surficial geology, extent 

and saturated thickness of sand and gravel aquifers, extent of 

confining units, bedrock-surface elevation beneath valleys, 

major lineaments, and the locations of wells for which records 

are available were delineated on an interactive map. 

Currently (2013), groundwater is the primary source of 

water supply in the study area. Several public water-supply 

systems withdraw groundwater from production wells in 

valley areas; elsewhere, domestic wells are used for water 

supply. Community-supply wells tap both sand and gravel and 

fractured bedrock aquifers; most domestic wells tap fracturedbedrock aquifers.

Thick, saturated sand and gravel deposits are limited 

in areal extent but form several localized, productive 

aquifer zones within the valley-fill sediments. Hydraulic 

interconnection among these zones is largely untested. Finegrained lacustrine deposits form extensive confining units 

above some aquifer material. Till deposits that extend into 

valleys also confine sand and gravel or bedrock aquifers. The 

study area was divided into three sections—south, central, 

and north.

The south section of the study area, from Harriman south 

to the Rockland County and New Jersey borders, includes 

the south-draining valleys of the Ramapo River and Summit 

Brook. South of the wide valley area at Harriman, the valleys 

are narrow and the valley-fill aquifers are largely untested; 

the most favorable aquifer conditions are likely at Arden 

and where major tributary streams enter the valley, between 

Southfields and We-Wah Lake. At Harriman, the Ramapo 

River valley fill has water-resource potential from ice-contact 

sand and gravel deposits.

The central section of the study area encompasses the 

headwater drainage area of the Ramapo River, from Harriman 

to Monroe and Kiryas Joel. The valley-fill aquifer material is 

generally thin, mostly unconfined, and underlain by glacial 

till. Shallow production wells tap parts of this aquifer, and 

appear most productive when sited near surface-water bodies. 

Production wells in the section are frequently completed in the 

underlying bedrock.

The north section of the study area encompasses the 

watershed of north-draining Woodbury Creek to just north of 

its confluence with Moodna Creek. The width of the valley 

bottom and type of valley-fill deposits vary considerably 

within the valley. The section likely has the greatest waterresource potential—both confined and unconfined aquifers are 

present and the village of Woodbury and town of Cornwall 

draw water supply from production wells. Aquifer potential 

appears most promising north of Central Valley, but several 

areas in this section are largely untested.

Valley-fill aquifers are modest resources within the area, 

as indicated by the common practice of completing supply 

wells in the underlying bedrock rather than the overlying 

glacial deposits. Groundwater turbidity problems curtail use 

of the resource. However, additional groundwater resources 

have been identified by test drilling, and there are remaining 

untested areas. New groundwater supplies that stress 

localized aquifer areas will alter the groundwater flow system. 

Considerations include potential water-quality degradation 

from nearby land use(s) and, where withdrawals induce 

infiltration of surface-water, balancing withdrawals with flow 

requirements for downstream users or for maintenance of 

stream ecological health.

Introduction

This study is a continuation of a series of hydrogeologic 

appraisals that have been conducted since 1980 in cooperation 

with the New York State Department of Environmental 

Conservation (NYSDEC) through the Aquifer Mapping 

Program. These reports provide a foundation for wellhead 

protection programs, water-resource management and 

planning decisions, and groundwater remediation in upstate 

New York.
2 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

In 2011, the U.S. Geological Survey (USGS), in 

cooperation with the NYSDEC, began an appraisal of the 

valley-fill aquifer system in a 23-mile (mi) reach of the 

Ramapo River-Woodbury Creek valley and adjacent areas 

in eastern Orange County, New York (fig. 1). The county is 

undergoing rapid population growth— between 2000 and 

2010, population increased by 9.2 percent in the county 

overall and by 20 percent or more in the Towns of Monroe 

and Woodbury (Orange County Department of Planning, 

2014). Thus, an understanding of water-resource potential and 

limitations is a priority for the NYSDEC.

Purpose and Scope

This report summarizes the hydrogeology of the valleyfill aquifer system in the 23-mi long Ramapo River-Woodbury 

Creek valley and in the western spur of the upper Ramapo 

River valley in eastern Orange County, N.Y. (figs. 1A and 

B). The area encompasses part or all of the towns of Tuxedo, 

Monroe, Woodbury, and Cornwall, and the villages of Tuxedo 

Park, Monroe, Harriman, Kiryas Joel, and Woodbury. An 

interactive map plate was constructed with several layers of 

information:

• Extent of the valley-fill aquifer system 

• Surficial geology

• Thickness of saturated sand and gravel 

• Extent of subsurface lacustrine confining units

• Elevation of the bedrock surface within the valley 

• Major lineaments, identified from light detecting and 

ranging (lidar) imagery 

• Locations of geologic sections and links to accompanying illustrations

• Well and seismic-survey locations

• Locations of former meltwater channels

• Base maps

• High-resolution, shaded lidar imagery of land surface 

• 1:24,000 scale topographic maps

Figures depict the study area, hydrogeologic sections, 

and favorable water-resource areas within the Ramapo RiverWoodbury Creek valley. Accompanying text summarizes 

the bedrock and glacial geology, the current (2013) use of 

water resources, and the hydrogeologic framework of glacial 

deposits within the valley areas. A table of well data is 

included in appendix 1.

Previous Investigations

Surficial geology (Pleistocene glacial and post-glacial 

Holocene deposits) has been mapped several times in the 

study area: (1) unpublished maps of surficial geology were 

prepared for the construction of the New York State Thruway 

(Interstate 87, fig. 1A; on file at USGS, Troy, N.Y.), (2) a map 

of the surficial geology of Orange County by Frimpter (1972), 

(3) SSURGO soils datasets, which describes soil parent 

material and characterizes the uppermost 5 to 10 feet (ft) of 

overburden (U.S. Department of Agriculture, 2011, derived 

from the soil survey of Orange County, U.S. Department of 

Agriculture, 1981), and (4) a regional map (1:250,000 scale) 

of surficial geology compiled by Cadwell (1989). Stanford 

(1992, 2004) mapped the surficial geology of parts of 

the Sloatsburg and Ramsey quadrangles (1:24,000 scale) 

immediately south of the study area in New Jersey.

Existing groundwater supplies in the area were developed 

on the basis of many local exploratory investigations and wellfield evaluations performed by private consultants. A notable, 

areally extensive early test-well drilling program for the town 

of Cornwall was performed by Hazen and Sawyer (1963).

Two county-wide efforts (Frimpter, 1970, 1972; Leggette, 

Brashears, and Graham, Inc.,1994) represent substantial work 

in hydrogeologic characterization (aquifer delineation) and 

water-resource assessment within the study area. Frimpter 

(1972) classified aquifer conditions throughout the valley 

area and assessed the water-resource potential of four aquifer 

subareas. Leggette, Brashears and Graham, Inc. (1994) 

compiled and synthesized well, aquifer, and water-use data, by 

town, from local consultants; this study used the classification 

scheme of Frimpter (1972) and the updated well and water-use 

datasets to describe groundwater resources of the county.

Bedrock Geology

Previous studies during the 1960s and 1970s mapped a 

variety of bedrock types in the study area (Fisher and others, 

1970; Jaffee and Jaffee, 1973; Dodd,1965) and bedrock 

mapping in the study area is ongoing (Gates and Valentino, 

2000; Gates and others, 2001; Valentino and others, 2004; 

McNamara and others, 2008). Bedrock in the southern 

and eastern parts of the study area consists of resistant 

Precambrian age metamorphic rocks (mostly gneiss) of the 

Hudson Highlands region. Bedrock in the northwestern part 

of the study area consists of folded and faulted clastic and 

carbonate sedimentary rocks of Cambrian through Devonian 

age, which lie within the Hudson-Mohawk Lowlands or 

Great Valley physiographic region (fig. 1B; Fisher and others, 

1970; Isachsen and others, 2000). The sedimentary rocks are 

subdivided into predominantly clastic and carbonate areas 

in fig. 1B. The clastic rocks include resistant sandstones 

and conglomerates that underlie high-elevation features—

Schunemunk Mountain (the Schunemunk Conglomerate 
Introduction 3

A

Summit Brook

0 1 2 3 4 MILES

0 1 2 3 4 KILOMETERS

Peckman’s 

Pond

Mombasha 

Lake

Woodbury Creek

INTERSTATE 87

ROUTE 17 (INTERSTATE 86)

Ramapo River

Tuxedo 

Lake

Mineral Spring Brook

INTERSTATE 87

NEW YORK

NEW JERSEY

Tuxedo 

Park

Monroe Harriman

Kiryas 

Joel

Woodbury

Town of 

Cornwall

Town of Woodbury

Town of Tuxedo

Town of Monroe

ORANGE COUNTY

ROCKLAND COUNTY

Eagle

Valley

Southfields

Arden

Central

Valley

Highland

Mills

Mountainville

Cornwall

Schunemunk Mountain

Newburgh

Junction

Base from Orange County GIS Division, 10-foot digital elevation model, 2004, NAVD 88

Universal Transverse Mercator projection, custom, NAD 83 

Moodna Creek

Midvalley 

drainage divide

Storm King

Art Center

ROUTE 17

(INTERSTATE 86)

74°10' 74°

41°20'

41°10'

EXPLANATION

Elevation, in feet above

North American Vertical Datum

of 1988 (NAVD 88)

1,800 

0

Village (incorporated) labeled 

in brown. Village of Woodbury

covers the Town of Woodbury 

except for the Village of 

Harriman

Watershed boundary

Study area boundary

Hamlet

Study area

NEW YORK

Figure 1A. Topography, political boundaries, major roads, and hydrography of the Ramapo River-Woodbury Creek study area in 

eastern Orange County, New York. Note: Village of Woodbury boundary is coincident with Town of Woodbury boundary except for the 

Village of Harriman area that is within the Town of Woodbury.
4 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

Summit Brook

74°10' 74°

41°20'

41°10'

Mapped faults (as compiled in Isachsen 

and McKendree, 1977; A. Gates, 

D. Valentino, written commun., 2013)

Lineaments, identified from lidar imagery

Study area boundary

EXPLANATION

Metamorphic rock 

of the Hudson Highlands

Clastic rocks (predominantly)—

coarse-grained rocks mostly underlie 

Schunemunk Mountain and resistant 

ridges and generally fine-grained clastic 

and carbonate rock underlie lower 

elevations

Carbonate rock—limestone or dolostone, 

with minor shale

Generalized bedrock geology

Major valley-forming lineament 

composed of several fault traces

Sedimentary rock 

Hamlet or village center

A Hill referenced in text

A

B

Schunemunk Mountain

Woodbury Creek

Ramapo River

Mineral Spring Brook

ORANGE COUNTY

ROCKLAND COUNTY

Eagle

Valley

Southfields

Arden

Central Valley

Highland Mills

Mountainville

Cornwall

Newburgh

Junction

Base from Orange County GIS Division, 10-foot digital elevation model, 2004, NAVD 88

Universal Transverse Mercator projection, custom, NAD 83 

Moodna Creek

Woodbury

Falls

Falls

Harriman

Monroe

Kiryas 

Joel

0 1 2 3 4 MILES

0 1 2 3 4 KILOMETERS

Study area

NEW YORK

NEW YORK

NEW JERSEY

Geology and faults modified from Fisher and others, 1970;

A. Gates and D. Valentino, written commun., 2013;

and Isachsen and Mc Kendree, 1977

B

Figure 1B. Generalized bedrock geology, mapped and inferred faults, and lineaments identified from light detection 

and ranging (lidar) imagery of the Ramapo River-Woodbury Creek study area in eastern Orange County, New York.
Introduction 5

[as noted in Rickard, 1975] and the Bellvale Formation) and 

a low, straight ridge (hill A, fig. 1B) east of Schunemunk 

Mountain composed of the Schawangunk Formation (Epstein, 

1993). Fine-grained, less resistant clastic rocks (for example, 

the Martinsburg Formation and the Esopus Shale) or faulted 

bedrock units generally underlie low-elevation areas (most 

of the Woodbury Creek valley and areas to the north). The 

carbonate rock is limestone and dolostone (with minor shale 

and chert) of the Cambrian-Ordovician age Wappinger Group, 

which underlies valley areas in the central part of the study 

area and locally in the southern and northern parts of the 

study area.

Bedrock is faulted and fractured in the study area 

(fig. 1B), and most of the valleys are coincident with 

mapped or inferred faults or with linear topographic features 

(lineaments). A major linear feature that extends southwestnortheast along the length of the study area (fig. 1B) is 

formed by several fault segments that underlie parts of the 

valleys of Summit Brook, the Ramapo River, Woodbury 

Creek, and Mineral Spring Brook. This major linear feature is 

herein referred to as the main fault valley. Both the southern 

reach of the Ramapo River valley and the northern reach of 

Woodbury Creek valley depart from the main fault valley 

and follow other faults. In faulted valley areas underlain by 

sedimentary rock, drillers’ well logs commonly describe 

intervals of rotten, deeply weathered bedrock or clay. A quarry 

in the faulted Woodbury Creek valley area also exposes 

pervasively fractured rock. The carbonate rocks have been 

modified by karst development (dissolution and creation of 

cavities or fissures) in addition to modifications by faulting 

and deep weathering.

Glacial Geology

The glacial-drift deposits of the study area (Pleistocene 

age) consist largely of thin or thick till over bedrock in upland 

areas and stratified deposits in the valleys (fig. 2). Thick 

till is most common on upper topographic slopes that faced 

advancing ice or on lower lee-side slopes of large topographic 

features, such as Schunemunk Mountain.

Stratified-drift deposits provide evidence of the sequence 

of deglaciation in the area. Deposits in the Ramapo River 

valley as far north as Arden indicate that meltwaters drained 

southward, the meltwaters were sufficiently impounded or 

impeded by glacial-drift dams to create a shallow proglacial 

lake in which lacustrine sand was deposited. A pause in the ice 

retreat at Arden resulted in the deposition of thick sand and 

gravel (an outwash head), whose upper surface is well above 

the present-day flood plain. Outwash prograded downvalley 

over the lacustrine deposits. Ice-contact deposits along valley 

walls east of Harriman and in the upper Woodbury Creek 

valley indicate that meltwater drained within or adjacent to 

the ice from north to south across the present-day midvalley 

drainage divide (figure 1B). Ice retreat north from Arden 

resulted in the impoundment of meltwater behind, and partial 

incision of, the sediment build up at Arden. The partial 

incision of the deposits at Arden or of a downvalley plug of 

glacial drift controlled the level of a proglacial lake north 

of Arden that occupied the broad valley area at Harriman. 

Meltwater from the west-to-east reach of the Ramapo River 

valley northwest of Harriman was limited and discharged into 

the lake at Harriman.

 The proglacial lake at Harriman progressively expanded 

northward as the ice retreated. The elevation of a kame delta at 

Highland Mills marks a lake level of 545–550 ft above North 

American Vertical Datum 1988 (NAVD 88), which indicates 

that the proglacial lake was continuous southward across the 

present-day midvalley divide (at about 526 ft) to the Arden 

area. Substantial valley-fill deposits in the Arden area, with 

terrace levels around 545–555 ft, may have provided at least 

a temporary control on the lake level. The lake level likely 

declined as the valley-fill deposits at Arden or a downvalley 

control were incised. Eventually, the present-day midvalley 

divide became the outlet and control for the lake in the 

Woodbury Creek valley. A pause in ice retreat in the Highland 

Mills-Woodbury area resulted in the greatest accumulation 

of sand and gravel in the Woodbury Creek valley, adjacent 

to the ice tongue. North of this area to Mountainville, sand 

and gravel deposition was mostly limited to subglacial 

meltwater channels or lacustrine fans, over which fine-grained 

lacustrine deposits or till were later deposited. Further ice 

retreat initiated eastward drainage of water impounded west 

of Schunemunk Mountain and in the Woodbury Creek valley 

along pathways between the ice margin and the north edges 

of Schunemunk Mountain and the Hudson Highlands into 

a lake in the Hudson valley with a level of less than 400 ft 

(Connally and Sirkin, 1967; Connally and others, 1989). As 

lake level in the Woodbury Creek valley dropped to the new 

base level, northward drainage in Woodbury Creek valley was 

initiated and the midvalley drainage divide was established. 

The deposition of sand and gravel ceased and fine-grained 

lacustrine sediments were deposited in the Woodbury Creek 

valley between Mineral Spring Brook and Mountainville. Lake 

drainage from the lowlands west of the study area (Connally 

and Sirkin, 1967; Connally and others, 1989) through the 

Moodna Creek valley at the north edge of Schunemunk 

Mountain both scoured the till and deposited localized 

sand and gravel. Areas of ice-contact sand and gravel were 

deposited north of Moodna Creek as ice retreat continued. 

Subsequent draining of the lakes in the Hudson River valley 

and the Woodbury Creek valley initiated downcutting of the 

glacial deposits and deposition of Holocene alluvial deposits 

(flood-plain alluvium and alluvial fans).

 Overview of Water-Resource Use

Groundwater is the source for most water supplies in the 

study area. Community groundwater supplies from production 

wells serve about 41,000 people in Kiryas Joel village, 

Harriman village, and the town and village of Woodbury, 
6 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

sir2014-5156_heisig_fig 02

74°15' 74°10' 74°5' 74°

41°25'

41°20'

41°15'

41°10'

Base from Orange County GIS Division, 10-foot digital elevation model, 2004, NAVD 88

Universal Transverse Mercator projection, custom, NAD 83 

Broad valley area

Schunemunk

Mountain

HUDSON

HIGHLANDS

HUDSON HIGHLANDS

HUDSON HIGHLANDS

Moodna Creek

Woodbury 

Creek

Ramapo 

River

Ramapo 

River

HUDSON LOWLANDS

Woodbury

Central Valley

Mountainville

Eagle Valley

Monroe

Harriman

Arden

Tuxedo Park

Kiryas 

Joel

Highland Mills

Southfields

Peckman’s 

Pond

Woodbury Falls

Mineral Spring Brook

Falls

Summit 

Brook

Midvalley 

drainage divide

HUDSON LOWLANDS

Orange - Rockland 

Lakes

Monroe 

Ponds

We-Wah 

Lake

Tuxedo

Lake

Newburgh

Junction

South Section

North Section

Central Section

0 1 2 3 4 MILES

0 1 2 3 4 KILOMETERS

EXPLANATION

Elevation, in feet above

North American Vertical Datum of 1988

(NAVD88)

1,800 

 0

Thick till (greater than 50 feet thick)

Stratified-drift aquifer extent

Thickness of saturated sand and 

gravel, in feet—dashed where inferred

10

50

Surface water body

Hamlet or village center

Section boundary

Study area boundary

Study area

NEW YORK

ORANGE COUNTY

ROCKLAND COUNTY

NEW YORK

NEW JERSEY

Figure 2. The south, central, and north sections of the study area, the stratified-drift aquifer extent, aquifer areas of thick 

(10 feet or greater) saturated sand and gravel deposits, and the extent of thick till, Orange County, New York.
Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System 7

whereas community surface-water supplies serve about 

11,500 people in Monroe village and town (from Mombasha 

Lake) and Tuxedo Park village (from Tuxedo Lake) (U.S. 

Environmental Protection Agency, [n.d.]). Groundwater is the 

sole source for all individual domestic supplies outside of the 

water districts served by the community water systems.

Groundwater is withdrawn from both sand and gravel 

(glacial) and fractured-bedrock aquifers. The highest well 

yields are obtained from production wells completed with 

screens in sand and gravel—the highest sustainable yields 

from these wells are typically about 350–400 gallons per 

minute (gal/min) based on a review of records on file at 

the Orange County Department of Health. However, thick, 

saturated sand and gravel aquifers are limited in extent—

only about 7 percent of wells in appendix 1 are completed 

in sand and gravel. The bedrock aquifer is widely used for 

domestic groundwater supply, especially in upland areas. 

Community water supplies commonly use the sedimentary 

bedrock aquifers that underlie valley areas north of Arden 

(fig. 1); sustainable yields from these production wells tapping 

bedrock are on the order of 100–200 gal/min. 

High turbidity is a common problem in bedrock 

production wells; clays in deeply weathered zones, which 

are likely related to faulting or to lithologies susceptible to 

weathering (carbonate, arkosic sandstone, and micaceous 

gneiss) or clays present as infillings in karst features in 

carbonate rock, are suspended by the rapid groundwater 

flow associated with pumping. Furthermore, accumulation 

of clay on screens and pumps can decrease well yields over 

time (D. Lindsey, Riddick Associates.; T. Cusack, Leggette, 

Brashears, and Graham, Inc.; oral commun., 2012).

Data Sources and Methods

Surficial geology, subsurface deposits, and aquifer 

boundaries were based on well-log data, SSURGO digital soilsurvey database (U.S. Department of Agriculture, 2011), lidar 

imagery, and previously compiled geologic maps. The aquifer 

boundary or “aquifer extent” is the extent of contiguous 

stratified-drift deposits within valleys, including largely 

unsaturated deposits on adjacent hillside areas.

Sources of well and test-boring records include previous 

USGS groundwater studies (especially Frimpter, 1970; and 

the USGS National Water Information System [NWIS]; U.S. 

Geological Survey, 2001), the NYSDEC Water Well Drillers 

Registration Program, the New York State Thruway Authority, 

and New York State Department of Transportation. All records 

collected for this study are compiled in appendix 1 and were 

entered into the USGS NWIS database (U.S. Geological 

Survey, 2001), which is accessible at http://waterdata.usgs.

gov/nwis/.

Passive seismic, or horizontal-to-vertical (H/V) ambientnoise seismic surveys, were carried out at 33 sites to estimate 

the thickness of sediments overlying bedrock. The H/V passive 

seismic method uses a single broadband three-component 

(x, y, and z directions) seismometer to record ambient seismic 

noise. The ratio of the averaged horizontal (x, y) to vertical 

(z) frequency spectrum is used to determine the fundamental 

site resonance frequency, which can be interpreted using 

regression equations to estimate sediment thickness overlying 

bedrock (Lane and others, 2008). The most distinct H/V peaks 

and best estimates of sediment thickness were at sites with 

stratified drift over bedrock. Indistinct or absent H/V peaks 

were generally indicative of till overlying bedrock with little 

or no stratified drift.

Hydrogeology of the Ramapo 

River-Woodbury Creek Valley-Fill 

Aquifer System

The extent of stratified drift (the valley-fill aquifer 

boundary) within the study area is depicted on plate 1; also 

shown are surficial geology, the thickness of saturated sand 

and gravel, the extent of confining units, major lineaments, 

and the elevation of the bedrock surface beneath the valleys. 

An overview map (fig. 2) shows the boundaries of the three 

sections of the study area (south, central, and north) that are 

discussed in the text as well as the aquifer extent, areas with 

thick saturated sand and gravel, and areas of thick till. The 

areas of thick saturated sand and gravel are conservatively 

delineated; isolated areas of saturated sand and gravel, 

particularly in the Woodbury Creek (north) section of the 

study area, may be more extensive than indicated. Four 

hydrogeologic sections illustrate the hydrogeologic framework 

of the valley fill.

South Section

This section extends from the midvalley drainage divide, 

which is northeast of Harriman, to southern boundary of the 

study area near the border of Orange County with Rockland 

County, N.Y. and Passaic County, New Jersey. (fig. 2). The 

south section includes the north-south reach of Ramapo River 

valley, its watershed, and the Summit Brook watershed.

Setting

The valleys and uplands of the south section (fig. 2) 

are underlain by resistant Hudson Highlands metamorphic 

bedrock, except where carbonate bedrock underlies the 

Ramapo River valley from Harriman and Newburgh Junction 

southward to Arden (fig. 1B, fig. 2; Jaffee and Jaffee, 1973; 

A. Gates, Rutgers University, D. Valentino, State University of 

New York at Oswego, written commun., 2013). The Ramapo 

River valley, follows a major fault, is linear and narrow 

(generally less than 0.4-mi wide) from Newburgh Junction 

through Arden to just beyond Southfields (fig. 1B). South 
8 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

of Southfields, the Ramapo River turns due south across the 

bedrock grain to Tuxedo Park along another lineament. This 

valley reach is narrow, and about 1 mi south of the southward 

turn, the Ramapo River flows on bedrock and over a waterfall 

before continuing south through Tuxedo Park and into 

Rockland County. The major fault valley (fig. 1B) continues to 

the southwest and is obstructed by till deposits that originally 

impounded Tuxedo Lake. These till deposits form the drainage 

divide between the Ramapo River and Summit Brook 

watersheds. Southwest of the divide, the Summit Brook valley 

continues southward to Eagle Valley and into New Jersey.

Till cover in upland areas is minimal, and glacial erosion 

has enhanced some of the lineament traces, as indicated on 

plate 1 and figure 1B. Drainage in upland areas is poor, and 

there are many wetlands and lakes that occupy glacially 

eroded depressions in the resistant bedrock or are ponded by 

accumulations of till.

Valley-Fill Deposits and Water-Resource Potential

Valley-fill deposits in the south section, from north to 

south include: (1) ice-contact sand and gravel partly covered 

by fine-grained lacustrine sediments in the broad valley area 

east of Harriman; (2) an increase in ice-contact and outwash 

sand and gravel at an inferred outwash head around Arden; 

and (3) downvalley of Arden, sandy lacustrine deposits 

overlain by outwash terrace remnants (appendix 2), with 

inferred coarser-grained valley fill where large tributaries 

enter the Ramapo River valley. In the southernmost reaches 

of the Ramapo River and Summit Brook valleys, valley-fill 

deposits are thin and become discontinuous (fig. 2; plate 1). 

For example, an isolated aquifer area is mapped in the Summit 

Brook valley at Eagle Valley and saturated sand and gravel 

thicknesses locally exceed 10 ft (fig. 2; plate 1).

The ice-stagnation area east of Harriman is characterized 

by ice-contact sand and gravel deposits at land surface on 

its southwest and eastern borders and by isolated ice-contact 

hummocks across the area (fig. 2; plate 1). Impoundment 

of water in the area before incision of the outwash head at 

Arden to the present-day elevation led to the deposition of 

lacustrine fine-grained sand, silt, and some clay (confining 

units in plate 1) over low-lying ice-contact sediments and till. 

Subsurface hydraulic connection among the underlying icecontact deposits is likely. Valley fill is relatively thin (typically 

less than 80 ft), as indicated by well logs and by the presence 

of a low bedrock hillock on the eastern side of the area. 

Water-resource potential is likely greatest in the ice-contact 

deposits along the southwest edge of the valley, as indicated 

by saturated thicknesses of sand and gravel that exceed 10 ft 

(plate 1; fig. 2). The maximum reported yield of a sand and 

gravel well in this area is about 250 gal/min (Metcalf and 

Eddy, written commun., 1972, on file at USGS).

The outwash head at Arden formed where the valley 

rapidly constricts to its narrowest reach. Terraces mapped 

previously as undifferentiated sand and gravel or as kame 

sand and gravel are present as high as 60–70 ft above the 

present-day river level. The valley fill at Arden changes 

downvalley (within a few hundred feet) from fine-grained 

lacustrine deposits overlying sand and gravel (fig. 3 at back of 

report) to all sand and gravel. The valley-fill deposits below 

the river level have good water-resource potential at this 

location, whereas the terrace deposits are mostly unsaturated

(plate 1).

Between Arden and Tuxedo Park (fig. 2), Ramapo 

River alluvium is bounded by terrace remnants, which were 

identified on the basis of lidar elevation data, at heights of 

10 to 60 ft above the river (appendix 2). The terraces are 

commonly described as sand or sand and gravel in well logs 

and are mapped as outwash sand and gravel on plate 1. These 

deposits also are mostly unsaturated. Alluvium along the 

Ramapo River is graded to bedrock in the river channel north 

of Tuxedo Park (appendix 2), and alluvium of major tributaries 

is graded to the present-day flood plain. In contrast, older 

alluvial fan deposits with little present-day streamflow appear 

to be graded to the terraces.

Little subsurface data are available for the valley-fill 

deposits south of Arden, but a few well logs indicate that fine 

lacustrine sand (likely including some silt) is present with 

perhaps some underlying coarse-grained sediments. Glacial 

lakes likely formed behind sediment dams (now eroded) as 

indicated by the terraces (appendix 2). Valley reaches where 

the largest tributaries join the Ramapo River are the most 

likely areas to have permeable, coarse-grained deposits. The 

best example of this setting is the 1.5- mi long Ramapo River 

valley reach south from Southfields. Several lineament valleys 

occupied by tributary streams intersect the Ramapo River 

valley in this reach (fig. 1B; plate 1). Leggette, Brashears, 

and Graham, Inc. (1994) inventoried one well in this area 

(completed in sand and gravel) that reportedly yielded about 

100 gal/min (see well O1564; plate 1 and appendix 1). The 

southern extent of contiguous aquifer material in the Ramapo 

River valley ends just south this reach, where the Ramapo 

River exits its original fault-controlled valley and flows due 

south along another valley (partly over bedrock) towards 

Tuxedo Park. A local aquifer area of limited thickness is 

depicted at Tuxedo Park.

South of the Ramapo River-Summit Brook drainage 

divide, Summit Brook crosses a small, isolated area of the 

stratified-drift aquifer at Eagle Valley (fig. 2; plate 1). Valleyfill deposits of sand or sand and gravel reach a maximum 

thickness of 50 ft (perhaps up to 30 ft of saturated thickness), 

as indicated by well logs within this area. 

Central Section

The central section of the study area includes the 

headwater reach of the Ramapo River, which flows eastward 

from the village of Monroe to Harriman. This section also 

includes the surrounding low uplands that are characterized by 

substantial areas of thick till (fig. 2; plate 1).
Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System 9

Setting

The central section is bounded on the north and south 

by resistant rock with little or no till cover—on the north by 

the resistant conglomerates and sandstones of Schunemunk 

Mountain (about 800 ft of relief) and on the south by 

metamorphic rock of the Hudson Highlands (about 600 ft of 

relief). The watershed divide northwest of Monroe village is 

only about 20 ft higher than the headwaters of the Ramapo 

River. The valley, which is fault controlled (Jaffee and Jaffee, 

1973; A. Gates, Rutgers University, D. Valentino, State 

University of New York at Oswego, written commun., 2013), 

is primarily underlain by carbonate rock and minor shale 

of the Wappinger Group (fig. 1B; fig. 4 at back of report). 

Most low-elevation areas adjacent to the Ramapo River are 

underlain by clastic and carbonate sedimentary bedrock of 

Cambrian-Ordovician to Devonian age. (Jaffee and Jaffee, 

1973; A. Gates, Rutgers University, D. Valentino, State 

University of New York at Oswego, written commun., 2013). 

The valley is poorly developed topographically, at least partly, 

because it was transverse to the direction of glacial ice flow; 

hence, glacial erosion was minimal and deposits of till within 

it are generally thick. The Ramapo River exits the central 

section of the study area at its eastern boundary with the 

south section—at the broad valley area immediately east of 

Harriman (fig. 2).

Valley-Fill Deposits and Water-Resource Potential

Till is the thickest and most widespread glacial deposit 

within the central section, and commonly underlies the 

stratified valley-fill deposits (fig. 4 at back of report). Thick 

till was deposited by south-flowing ice on the lee side of 

Schunemunk Mountain at low elevations and across the 

adjacent Ramapo River valley areas. Thick till deposits also 

form the present-day Ramapo River-Woodbury Creek drainage 

divide (fig. 2). Till deposits on the lee side of Schunemunk 

Mountain appear to be a till shadow (Coates, 1966). Thick till 

also forms an apron on the south side of the east-west Ramapo 

River valley, which faced south-flowing ice. Witte (2011) and 

Stanford (1992) have described similar deposits in northern 

New Jersey and attribute them to pressure melting of glacial 

ice as it impinges on areas of higher topography.

The inputs of meltwater and sediment to this upper reach 

of the Ramapo River valley were small and were mostly from 

local ice. However, there also may have been brief periods 

of meltwater input from across the low divide northwest of 

Monroe village and, perhaps, from across the high ridge of 

Schunemunk Mountain. Sediment deposition in the poorly 

drained east-west valley reach mostly consists of thin outwash 

deposits around the till hills, as depicted in figure 4 and 

plate 1. Well yields as high as 450 gal/min have been reported 

from the thin outwash adjacent to the Mountain Lakes 

and adjacent the Ramapo River (plate 1). Coarse-grained 

sediments also were deposited in the east part of the section as 

the meltwaters entered the proglacial lake at Harriman. These 

saturated, shallow sands and gravels are used for water supply 

by the village of Harriman, and the highest reported yield of 

wells completed in sand and gravel in the Harriman area is 

about 200 gal/min.

The thickest sand and gravel deposits in the valley of the 

central section (about 85 ft thick; well O1566, appendix 1) are 

of local extent in the village of Monroe at the west end of the 

section (fig. 2; plate 1). These deposits presumably are derived 

from the relatively limited eastward meltwater drainage (fig. 2; 

plate 1) over the low divide from the west. Drainage from the 

west is a plausible sediment source because soil maps indicate 

ice-contact deposits at the north end of Orange-Rockland 

Lakes at elevations as high as 625 ft above NAVD 88, whereas 

the floor of the meltwater channel divide between OrangeRockland Lakes and the Monroe Ponds has a maximum 

elevation of only 606 ft.

Thinning of the ice over Schunemunk Mountain would 

have disconnected the leeward ice from active ice flow, and 

downwasting of that ice would have occurred with limited 

transport of sediment by meltwater beyond this area. However, 

some limited meltwater input from ice on the north side of 

Schunemunk Mountain appears plausible. Notches along the 

ridgeline of southern Schunemunk Mountain contain rounded 

cobbles in the soil, indicating possible water transport at some 

point during deglaciation; these ridgeline notches are paired 

with notches on the lee hillside and with several lakes at the 

bottom of the notches. The lakes are contiguous with several 

low-relief drainage channels about 100 to 500 ft wide that 

cross the low upland area and feed into the valley (plate 1); 

the channels are visible in lidar imagery and are indicated, in 

part, by soil data (soil with alluvial parent material or those 

described as extremely stony [possibly washed by meltwater]). 

Up to 60 ft of stratified sediment has been reported in 

some low-gradient sections of these channels, consisting of 

thin sand and gravel beneath fine-grained sediments. The 

sand and gravel and underlying bedrock have previously 

been tapped for public supply (plate 1 for example, wells 

O1565–67; Leggette, Brashears, and Graham, Inc., 1987). 

Well yields ranged from 9 to 120 gal/min. Where these 

channels meet the valley, sand and gravel deposits have been 

noted in exploratory drilling logs (plate 1 and appendix 1; 

wells O1554, O3501, O1482, O5257, Leggette, Brashears, and 

Graham, Inc., 1997; 1999), and some saturated thicknesses 

may be sufficient to support production wells in sand and 

gravel or bedrock.

Well yields in the central section are highest in valleybottom areas near the Ramapo River. Despite maximum 

reported test-well yields on the order of hundreds of gallons 

per minute, most identified sand and gravel deposits in the 

central section have characteristics that indicate more modest 

potential yields. Depths to bedrock as much as 137 ft have 

been reported in areas of stratified drift, but the surficial 

aquifers are generally underlain by thick till (fig. 4 at back 

of report), which limits the discharge of groundwater from 

bedrock to the surficial aquifer. The saturated thickness of 

sand and gravel typically is less than 30 ft; aquifer width 
10 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

is generally less than 2,000 ft and often less than 1,000 ft. 

Induced infiltration from the Ramapo River may augment 

this resource, but given the small watershed of the Ramapo 

River and its tributaries, induced infiltration cannot be relied 

on to sustain large withdrawals during extended dry periods. 

Bedrock wells that derive some of their yield from overlying, 

permeable glacial deposits are generally the most reliable 

sources of water supply in the area.

North Section

This section covers most of the northward-draining 

study area. It includes the entire 7.2-mi length of Woodbury 

Creek and a 2.5-mi long reach of Moodna Creek upstream 

and downstream from the confluence with Woodbury Creek 

(fig. 2).

Setting

The north section of the study area (fig. 2), drained by 

Woodbury and Moodna Creeks, is bounded by Schunemunk 

Mountain on the west side and the Hudson Highlands on the 

east side. Relief in the section is greater than 1,000 ft. The 

present-day Woodbury Creek valley is set within a broad 

valley (1.7 to 2.5 mi in width) that is outlined in figure 2. The 

north end of the section opens into the Hudson Lowlands, 

an area of low relief. The upper 4-mi reach of the Woodbury 

Creek valley is floored by alternating wide and narrow (or 

non-existent) flood plain areas and includes a waterfall at 

the northern end (fig. 2). This reach is mostly walled by 

relatively low-relief sedimentary rock on both sides. The 

lower 3-mi reach of the Woodbury Creek valley is more 

regular, is about 0.5-mi wide, and is walled by the sandstones 

and conglomerate of Schunemunk Mountain on the west and 

by metamorphic Hudson Highlands rock on the east. Valleybottom areas are underlain by faulted carbonates, sandstones, 

and shales (figs. 1B, figs. 5, and 6 at back of report). The 

reach of Moodna Creek within the study area traverses the 

Hudson Lowlands west to east, just north of Schunemunk 

Mountain and the Hudson Highlands. The underlying bedrock 

is primarily shale and siltstone with some local areas of 

sandstone and carbonate (fig. 1B, fig. 6 at back of report).

The drainage divide between the Woodbury Creek 

and Ramapo River watersheds in the main fault valley is 

coincident with low hills that are primarily composed of till, 

but also include some ice-contact deposits. The hills along the 

drainage divide have been excavated or reshaped by human 

activities over much of the area; comparison of lidar elevation 

data with an old (1935) topographic map (Monroe, New York, 

USGS quadrangle map, 1:24,000 scale) indicates that the low 

point of the divide was about 526 ft above NAVD 88 before 

human alteration. From this divide, Woodbury Creek valley 

initially follows the main fault trace (fig. 1B) northward for 

a short distance, shifts to the west at Central Valley, and then 

continues northward parallel to the main fault trace until its 

confluence with Moodna Creek. The headwater section of 

Woodbury Creek above the falls at Woodbury is characterized 

by a low gradient; the elevation of the land surface drops only 

about 50 ft over 3.5 mi (fig. 2; appendix 2). Downgradient of 

the bedrock control at the falls, the gradient to the confluence 

with Moodna Creek is much higher—elevation drops by about 

200 ft over 3.7 mi.

Advance of glacial ice in the broad area between 

Schunemunk Mountain and the highest hills of the Hudson 

Highlands (fig. 2) resulted in the deposition of thick till aprons 

on slopes facing the ice advance and on some lee sides of low 

hills. As the glacial ice thinned and receded, meltwater from 

the ice in the low hills east of the Woodbury Creek valley 

would have drained toward the valley, and, as a consequence, 

this eastern area shows no indication of stratified drift suitable 

for water-resource use.

Valley-Fill Deposits and Water-Resource Potential

The valley fill in the north section reflects the presence of 

ice-dammed proglacial lakes in the presently north-draining 

Woodbury Creek valley. Lake plains in depressions amidst 

widespread thick till characterize the upper 2 mi of the 

Woodbury Creek valley. Sand and gravel deposited during 

a pause in the ice retreat predominates in the valley reach 

between Highland Mills and the Woodbury Creek confluence 

with Mineral Spring Brook. North of this confluence, as far 

as Mountainville, fine-grained lacustrine deposits are the 

primary stratified deposit in the valley. In places, sand and 

gravel also was deposited in subglacial meltwater channels 

or lacustrine fans, over which lacustrine deposits or till were 

later deposited. North of Mountainville, within the low-relief 

Moodna Creek valley, stratified-drift deposits are very limited 

(fig. 2). The surrounding area is mostly covered by till, and 

sand and gravel occurs only in localized areas.

Five areas of aquifer material (identified by multiple well 

logs) are known to date (2013) along the Woodbury Creek and 

Moodna Creek valleys (fig. 2; plate 1). These sand and gravel 

deposits appear isolated from one another by either till and 

lacustrine deposits in the Mountainville and Central Valley 

areas or by pinchout of the aquifer where bedrock is exposed 

at land surface in the Woodbury Falls area. Three of the five 

areas are used for public supply or have been characterized 

for that eventual use. The valley-fill deposits in the Woodbury 

Creek valley are described below, from south to north.

The first area is immediately north of the midvalley 

divide between the Woodbury Creek and Ramapo River 

watersheds; ice-contact sand and gravel is mapped in surficial 

deposits near Peckman’s Pond (plate 1; fig. 2). From the 

mapped sand and gravel, a thin aquifer is inferred to extend 

northward beneath fine-grained sediments. However, this 

valley reach, almost to Central Valley, is broad, flat, poorly 

drained, and likely was occupied by a downwasting ice block 

with little subsequent sediment deposition. This interpretation 

is supported by the difference in elevation of the valley floor 

on either side of the drainage divide; the valley floor in the 
Groundwater Circulation 11

headwaters of Woodbury Creek is nearly 30 ft lower than the 

valley floor on the south side of the divide east of Harriman. 

Furthermore, there are no deep well or test-boring logs in this 

valley reach to verify the presence or thickness of an aquifer. 

Surficial sand and gravel is mapped from soils data along 

the west side of the valley, up to an elevation of 600 ft above 

NAVD 88, but a passive seismic measurement implies that 

thin sand and gravel over till occurs in this area. Thus, the 

saturated thickness of the surficial sand and gravel is likely 

to be thin. Farther north at Central Valley, Woodbury Creek 

is narrowly incised through a mass of glacial drift that is 

identified as till by soils data, by a shallow test boring, and by 

field observation. Sand and gravel may be present beneath this 

till, but without further information, this locale is not inferred 

to include any aquifer material.

The second aquifer area extends about 1.7 mi north from 

Central Valley through Highland Mills nearly to Woodbury 

Falls (fig. 2). It is characterized by valley-bottom lacustrine 

deposits in much of the southern two-thirds of the area and 

by mostly ice-contact deposits, including a kame delta and 

an eskerform feature, in the northern one-third of the area. 

No stratified material is present on the east side of this 

area; however, along parts of the lower hillsides of the west 

side, thinly saturated ice-contact material is mapped up to 

elevations of 600 ft, as in the area just north of the Ramapo 

River-Woodbury Creek drainage divide (fig. 2; plate 1). 

Ice-contact sand and gravel is present beneath the lacustrine 

deposits and is hydraulically connected with the near-surface 

ice-contact deposits to the north (Frimpter, 1972; p. 45–47). 

The village of Woodbury draws much of its water supply from 

this aquifer area.

The third aquifer area extends from Woodbury Falls 

about 2.5 mi north, nearly to Mountainville. For about 

1 mi north of Woodbury Falls to the Mineral Spring Brook 

confluence, the valley contains unconfined sand and gravel 

and the lower valley sides are mantled by thinly saturated sand 

and gravel deposited by south-flowing meltwater alongside an 

ice tongue in midvalley. Between Mineral Spring Brook and 

Mountainville, lacustrine clay, silt, and fine sand accumulated 

in the valley. Parts of the valley floor were later mantled by 

masses of till that apparently slid as landslides from the steep 

valley walls. In the northern 1.5 mi of this aquifer area, sand 

and gravel deposited by earlier south-flowing meltwater 

(within and beneath the ice) locally occurs on top of bedrock, 

beneath fine-grained lacustrine deposits or till (fig. 2; plate 1).

Aquifer tests have been performed on at least six 

wells within the third aquifer area, but currently (2013), 

none are being used for water supply. Yields between 30 

and 400 gal/min have been reported (Leggette, Brashears, 

and Graham, Inc., 2007, 2011; S. Gagnon, Orange County 

Department of Health, written commun., 2011). The maximum 

northern extent of this aquifer area is indicated by five test 

borings across the valley that show no aquifer material except 

for 2 ft of sand and gravel in one test boring (wells O1957–61, 

plate 1, appendix 1; Hazen and Sawyer, 1963; see also 

geologic section B–B′ in Frimpter, 1972).

Near Mountainville, the north end of Woodbury Creek 

valley is choked with thick accumulations of till on the valley 

flanks and beneath the valley floor (fig. 6 at back of report). 

The fourth aquifer area is defined by several well records 

showing that the till on the east side of the valley buries and 

confines an older sand and gravel deposit (fig. 2, fig. 6 at back 

of report; plate 1). 

A fifth aquifer area, similarly confined beneath till and 

also lacustrine clay, is present along Moodna Creek about 

1.5 mi northwest of Mountainville (plate 1). This aquifer is 

limited in areal extent, but productive. The eastern part of 

the aquifer area is tapped by domestic wells, whereas the 

western part is tapped for municipal supply by wells capable 

of yielding 300–350 gal/min (S. Gagnon, Orange County 

Department of Health, written commun., 2011). 

Beyond these locales, till is the predominant surficial 

deposit north of Moodna Creek. Available well log data 

indicate that other mapped ice-contact deposits in this area 

mostly overlie till and likely are thinly saturated. Additional 

subsurface data are needed to verify this, as there are 

indications of saturated sand and gravel at two isolated 

locations north of Mountainville (fig. 2; plate 1).

Groundwater Circulation

Groundwater circulation in the study area includes 

movement through both fractured bedrock and stratifieddrift aquifers. The ultimate source of water across the area 

is the infiltration of precipitation (recharge) at land surface. 

Recharge occurs over most land area where surficial deposits 

or bedrock are permeable enough to allow infiltration, except 

for those areas where groundwater typically discharges 

under natural conditions, such as most lakes, streams, and 

wetlands. Most groundwater circulation in upland areas is 

through fractured bedrock, is predominantly downslope, and 

occurs through the upper 100–300 ft of bedrock. A small 

amount of groundwater moves more slowly downward 

into deeper bedrock. If till in the uplands is permeable, 

particularly in areas of metamorphic rock, groundwater 

flow through these otherwise low-permeability deposits 

may also be important. This upland groundwater (in till and 

bedrock) moves downslope to valley areas unless it is first 

discharged to upland streams and wetlands or taken up by 

vegetation (evapotranspiration). Downslope movement of 

groundwater to valleys is controlled by bedrock structure 

and fracture permeability and is, therefore, not necessarily 

directly downslope.

Shallow hillslope groundwater likely will flow into 

the shallowest valley-fill deposits and toward the stream or 

discharge to land surface at springs if the shallow valleyfill deposits are not permeable. Precipitation that falls and 

infiltrates directly to unconfined aquifers on the valley bottom 

also will flow toward the stream. Natural shallow groundwater 

flow in valleys toward the stream will have a downvalley 
12 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

component, dependent on the valley gradient and geometry. 

Where tributary streams enter valleys across alluvial fans, 

they commonly lose flow as water in the stream infiltrates into 

the streambed (Randall, 1978) and replenishes the aquifer, if 

subsurface deposits are permeable.

Deeper groundwater flow from hillsides either moves 

into deep valley-fill deposits or maintains hydrostatic pressure 

in those deposits and is forced upward to discharge into 

shallower aquifer material. Increasing hydrostatic pressure 

with depth in valleys, whether the aquifer materials are 

confined or not, results in high groundwater levels (near or 

above land surface; levels above land surface result in flowing 

conditions) in deep valley wells under nonstressed conditions.

The midvalley surface-water divide between the Ramapo 

River and Woodbury Creek appears to be a groundwater 

divide as well. Few well logs in the immediate area of the 

divide imply till down to bedrock; however, subsurface 

pathways for groundwater movement across the divide, such 

as deep permeable sediments overlying a fault zone, could 

be present.

Water-Resource Considerations for the 

Valley-Fill Aquifer System

Groundwater resources within the valley-fill aquifer 

system are constrained by the discontinuous nature and limited 

thickness of saturated sand and gravel and by the relatively 

small size of streams in the area. Supply wells and test wells 

have been completed in many of the more extensive or 

relatively thick valley-fill deposits. Several areas with little 

subsurface data were noted within the study area that may 

have additional water-resource potential: 

1. The valley area between the midvalley divide and Central 

Valley appears largely unexplored—ice-contact deposits 

at Peckman’s Pond may extend northward beneath finegrained alluvium and, most likely, lacustrine deposits. 

2. A side valley that trends northeast from Central Valley 

east of linear hill A (figs. 1B and 2) is drained by a 

tributary of Mineral Spring Brook. This valley may 

have previously been a substantial drainage path prior to 

deposition of thick till that blocks its south end and, if so, 

it may have some permeable sediment at depth. 3.

3. Ice-contact deposits mapped north of Moodna Creek, 

at the northernmost extent of the study area, may have 

water-resource potential. Well logs from the west side of 

this deposit indicate thinly saturated sand and gravel over 

till. A few logs near the southern end of the Storm King 

Art Center (fig. 1A) describe thick sand and gravel but 

well log verification and locations were not definitive. 

4. The Ramapo River valley reach from Southfields to where 

the Ramapo River departs from the main fault valley is 

intersected by several fault- or lineament-based tributary 

valleys, which imply favorable aquifer conditions. 

5. Last, former meltwater channels identified south of 

Schunemunk Mountain on plate 1 have modest potential 

in reaches where the channel slopes were low and 

sediment infilling occurred. Sand and gravel beneath 

fine grained sediments has been identified and used for 

domestic supply and modest public supply (Leggette, 

Brashears, and Graham, Inc., 1987). Several of these areas 

are occupied by lakes and wetlands.

Considerations other than the limited areal extent and 

thickness of aquifer sediments also may place constraints 

on the use of groundwater resources in the study area. 

Contamination from human activities could potentially affect 

the quality of the groundwater, limiting its use for drinking 

water or other purposes. For example, infiltration of runoff 

contaminated by road salt can adversely affect groundwater 

quality; all valleys contain at least one major highway and 

the narrow valley of the south section contains two—the 

New York State Thruway (Interstate 87) and Route 17 

(Interstate 86). A supply well in a valley such as this would 

most likely divert shallow salt-affected water to the well 

that would have otherwise discharged to the valley stream. 

Other large areas of impervious surface may also contribute 

runoff with high dissolved solids to groundwater. Infiltration 

of fertilizers or pesticides in runoff from developed areas 

such as golf courses or residential lawns are another source 

of contamination that might affect groundwater quality in 

unconfined aquifers. Constraints on the use of the stratifieddrift aquifers also could arise because of a need to limit the 

effects of groundwater withdrawals on streamflows through 

induced infiltration, especially during summer low-flow 

periods when water demand is high. 

Several types of monitoring could provide useful 

information for further evaluation of the groundwater 

resources in the study area. Measurement of the rate(s) 

at which streamflows may be reduced by present-day 

groundwater withdrawals from nearby shallow, high-capacity 

wells, especially during summer low-flow periods when 

water demand is high, could provide useful information for 

evaluating the effects of withdrawals on streamflows. As the 

number of active production wells increases, especially in 

confined aquifer areas, long-term continuous groundwaterlevel measurements at dedicated monitoring wells between 

groups of production wells within and among aquifer areas 

would (1) provide an indication of the degree of hydraulic 

interconnection within the valley-fill aquifer system and 

(2) provide the context needed to evaluate the effects of 

seasonal and long-term pumping stresses on the aquifer system 

that can alert water managers to downward water-level trends 

that might indicate nonsustainable use of water resources.
References Cited 13

Summary

The Woodbury Creek-Ramapo River valley-fill aquifer 

system and associated water resources in eastern Orange 

County, New York, were investigated in cooperation with the 

New York State Department of Environmental Conservation. 

The aquifer system was delineated and characterized based 

on surficial deposits and landforms, subsurface information, 

and previous work in the area. An interactive map depicts 

the aquifer extent and thickness, surficial geology, and 

approximate bedrock elevation beneath valleys over base 

maps of shaded relief light detection and ranging (lidar) 

imagery and 1:24,000 scale topographic maps. An appendix 

of well data is also provided. The study area was divided into 

three sections for ease of discussion.

The south section is the south-draining part of the 

Ramapo River watershed where the river follows a narrow, 

fault-controlled valley. This section is primarily underlain 

by resistant metamorphic bedrock of the Hudson Highlands. 

Little available well-log data indicate that fine-grained 

deposits likely predominate within the valley fill, except 

(1) at and immediately south of Arden; (2) potentially at 

valley junctions with major tributary streams where influxes 

of coarse-grained sediments may have occurred, such as at, 

and south of, Southfields; and (3) where the valley broadens 

near Harriman and extensive coarse sand and gravel occurs. 

Lineaments that cross the valley may convey some additional 

water from upland areas.

The central section is the headwater watershed of 

the Ramapo River, including the villages of Monroe and 

Harriman. The low-relief, west-east valley is characterized 

by typically thin outwash sand and gravel deposits of limited 

areal extent that overlie till. High-capacity wells in shallow 

unconfined aquifer zones likely require induced infiltration of 

surface water to maintain well yield.

The north section has the greatest water-resource 

potential from valley-fill deposits, as indicated by well 

logs, present-day (2013) water use, and previously 

conducted aquifer tests. However, the valley-fill aquifers 

are discontinuous in several parts of this section: (1) near 

Woodbury Falls, where bedrock is exposed in the streambed; 

(2) south of Mountainville, where little or no gravel was 

penetrated by several wells and test borings; and (3) perhaps 

also at Central Valley, where till is mapped all across the 

valley. Both shallow unconfined and deeper confined aquifer 

zones have been identified. However, until pumping stresses 

are applied to the aquifer system and groundwater-level 

responses are monitored, the degree of hydraulic connection 

among aquifer areas and between the aquifers and surface 

water will remain largely unknown, as will the potential 

productivity of the aquifer system. Further exploration in the 

north section (as well as in parts of other sections) also may 

identify areas of aquifer material that are not apparent because 

of a lack of subsurface information.

References Cited

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Lower Hudson sheet: New York State Museum and Science 

Service, Map and Chart Series no. 40, scale 1:250,000.

Coates, D.R., 1966, Glaciated Appalachian Plateau—Till 

shadows on hills: Science, v. 152, p. 1617–1619.

Connally, G.G., and Sirkin, L.A., 1967, The Pleistocene 

geology of the Wallkill Valley, in Waines, R.H., ed., New 

York State Geological Association Guidebook, 39th annual 

meeting: State University of New York College, New Paltz, 

N.Y., p. A1–A21.

Connally, G.G., Sirkin, L.A., and Cadwell, D.H., 1989, 

Deglacial history and environments of the upper Wallkill 

Valley, in Weiss, Dennis, ed., New York State Geological 

Association Guidebook, 61st annual meeting, October 

13–15, 1989: Orange County Community College, 

Middletown, New York, p. 205–230.

Dodd, R.T., 1965, Precambrian Geology of the Popolopen 

Lake Quadrangle, southeastern New York: New York State 

Museum and Science Service, Map and Chart Series no. 6, 

39 p., 1 plate.

Epstein, J.B., 1993, Stratigraphy of Silurian Rocks in 

Schawangunk Mountain, southeastern New York, including 

a historical review of nomenclature—A description and 

partial revision of the physical stratigraphy: U.S. Geological 

Survey Bulletin 1839–L, 40 p.

Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, 

Geologic map of New York, Lower Hudson sheet: New 

York State Museum and Science Service, Map and Chart 

Series no. 15, scale 1:250,000.

Frimpter, M.H., 1970, Ground-water basic data, Orange and 

Ulster Counties, New York: New York State Department of 

Environmental Conservation, Water Resources Commission 

Bulletin 65, 93 p.

Frimpter, M.H., 1972, Ground-water resources of Orange and 

Ulster Counties, New York: U.S. Geological Survey WaterSupply Paper 1985, 80 p.

Gates, A.E., and Valentino, D.W., 2000, Geologic map of the 

Monroe 7.5 minute quadrangle, New York; New York State 

Geological Survey Open-File Report no. 1g1436.

Gates, A.E., Valentino, D.W., Chiarenzelli, J., and Volkert, 

R.A., 2001, Geologic map of the Sloatsburg 7.5 minute 

quadrangle, New York; New York State Geological Survey 

Open-File Report no. 1g1437.
14 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

Hazen and Sawyer Engineers, 1963, Exploratory and test well 

program May–December 1963, Village of Cornwall, N.Y., 

unpaged, 1 plate, scale 1:24,000. 

Isachsen, Y.W., Landing, E., Lauber, J.M., Richard, L.V., 

and Rogers, W.B., eds., 2000, Geology of New York—A 

simplified account (2d ed.): New York State Museum 

Educational Leaflet 28, 294 p.

Isachsen,Y.W., and McKendree, W.G., 1977, Preliminary 

brittle structure map of New York—Niagara-Finger Lakes 

sheet: New York State Museum Map and Chart Series no. 

31D, scale 1:250,000. 

Jaffee, H.W. and Jaffee, E.B., 1973, Bedrock geology of the 

Monroe Quadrangle, Orange County, New York: New York 

State Museum and Science Service, Map and Chart Series 

no. 20, 67 p., 1 plate.

Lane, J.W., Jr., White, E.A., Steele, G.V., and Cannia, J.C., 

2008, Estimation of bedrock depth using the horizontalto-vertical (H/V) ambient-noise seismic method, 

in Symposium on the application of geophysics to 

engineering and environmental problems, April 6–10, 2008, 

Philadelphia, Pennsylvania, Proceedings: Denver, Colo., 

Environmental and Engineering Geophysical Society, 13 p.

Leggette, Brashears, and Graham, Inc., 1987, Hydrogeologic 

evaluation of the Highland Lake Estates, Town of 

Woodbury, New York: Report for Carl Mays, Corkill and 

Seddon, Inc., variously paged.

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resources of Orange County, New York: Report for Orange 

County Water Authority, N.Y.,variously paged.

Leggette, Brashears, and Graham, Inc., 1997, Well 

completion report, Village of Monroe, ground-water 

exploration program: Report for Village of Monroe, N.Y., 

variously paged.

Leggette, Brashears, and Graham, Inc., 1999, Well 

completion report, Village of Monroe, ground-water 

exploration program: Report for Village of Monroe, N.Y., 

variously paged.

Leggette, Brashears, and Graham, Inc., 2007, Ground-water 

exploration program, Legacy Ridge, Town of Woodbury, 

N.Y.: Report for Legacy Ridge, variously paged.

Leggette, Brashears, and Graham, Inc. 2011, 72-hour pumping 

test report for well 1, Mountainville pump station parcel, 

Route 32, Cornwall, New York: Report for Village of Kiryas 

Joel, N.Y., variously paged.

McNamara, I., Cirmo, A., and Gates, A.E., 2008, Geologic 

map of the Cornwall 7.5 minute quadrangle, New York: 

New York State Geological Survey Open-File Report 2508.

Orange County Department of Planning, 2014, 

Population change 2000–2010: Goshen, N.Y., accessed 

March 3, 2014, at http://www.orangecountygov.com/

filestorage/124/1362/3210/Population_Change_2000-2010.

pdf.

Randall, A.D., 1978, Infiltration from tributary streams in the 

Susquehanna River Basin: U.S. Geological Survey Journal 

of Research, v. 6, no. 3, p. 285–297.

Rickard, L.V., 1975, Correlation of Silurian and Devonian 

rocks in New York State: New York State Museum and 

Science Service, Map and Chart Series no. 24, 16 p.

Stanford, S.D., 1992, Surficial geology of the Greenwood 

Lake and Sloatsburg quadrangles, Passaic, Bergen, and 

Sussex Counties, New Jersey: New Jersey Geological and 

Water Survey, Open File Map 6, scale 1:24,000.

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quadrangle, Bergen and Passaic Counties, New Jersey: New 

Jersey Geological and Water Survey, Open File Map 62, 

scale 1:24,000.

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(SSURGO) database for Orange County, New York, 

accessed October 30, 2011, at http://soildatamart.nrcs.usda.

gov/.

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water information system (SDWIS) database, accessed 

July 14, 2010, at http://oaspub.epa.gov/enviro/sdw_form_

v2.create_page?state_abbr=NY.

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map of the Popolopen Lake 7.5 minute quadrangle, New 

York: New York State Geological Survey Open-File Report 

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82, 13 p., scale 1:24,000.
Figures 3–6 15

Figures 3 through 6
16 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

sir2014-5156_heisig_fig3-6exp

EXPLANATION FOR FIGURES 3–6

(figures 3−6, location of cross sections shown on plate 1, http://pubs.usgs.gov/sir/2014/5156/)

Alluvium—Postglacial river and stream flood-plain deposits consisting predominantly of stratified silt and clean to silty sand, commonly with 

some gravel at the base of the deposit. Alluvium generally occurs within 10 feet (ft) of the present-day stream or river level. Thickness is as 

much as 15 to 25 ft. 

 

Alluvial fan—Fan-shaped accumulations of stratified silty sand and gravel, deposited by tributary streams where they enter the Ramapo 

River-Woodbury Creek valleys. Maximum thickness of fans may approach 40 ft, but is likely less than 20 ft for most fans

Alluvial fan deposits have relatively high permeability, but are relatively thin and largely unsaturated. Fan deposits are an important conduit 

for groundwater recharge if the underlying glacial deposits are permeable. Most fans in the northern half of the study area overlie 

fine-grained deposits that limit recharge

Artificial fill—Road and railroad embankments and landfills

Open water—Areas of open water such as streams, rivers, lakes, large ponds, and reservoirs

Outwash sand and gravel—Stratified, well-sorted sand and gravel deposited by glacial meltwater streams away from the ice front as 

valley-train outwash (originally spanning the width of the valley). Outwash terraces or topset beds of deltas near the receding ice front also 

are included. Outwash in the Ramapo River-Woodbury Creek valley is largely limited to the southward draining Ramapo River section. 

Outwash deposits are delineated within the short west to east section of the Ramapo River and from Arden downvalley to the south. Upper 

surfaces generally 20 to 60 ft above river level, except at the head of the outwash near Arden, where the valley is constricted and incision 

approaches 70 ft. Outwash sand and gravel deposits have very high permeability, but somewhat limited aquifer potential because of thin 

saturated thicknesses

Ice-contact sand and gravel—Undifferentiated ice-contact deposits of poor- to well-sorted sand and gravel with variable amount of silt that 

was deposited adjacent to, or beneath, within, or on top of melting glacial ice. Includes geomorphic features such as kames, kame terraces, 

kame deltas, eskers, and permeable hummocky terrain mostly within valleys. Coarse stratified deposits in the subsurface likely originated 

from subglacial drainage or subaqueous or lacustrine fans, deposited where meltwater discharged into proglacial lakes. Extreme variability 

in sorting, grain size, and thickness of individual beds. Moderate to high permeability, high permeability especially in coarse, well-sorted 

zones. Deposits situated at low altitude (below the valley floor) and with favorable characteristics (high permeability) form localized 

unconfined or confined aquifers

Lacustrine silt and clay or sand—Glaciolacustrine deposits of thinly to massively bedded silt, fine to very fine sand, and some clay. 

Deposited as lake-bottom sediments in proglacial lakes that formed as a result of the temporary dams created by ice, till moraines, or 

downvalley ice-marginal deposits such as high-outwash valley trains and kame moraine and kame delta deposits. Thicknesses can reach as 

much as 150 ft. These deposits have low permeability and form the principal confining unit in the Ramapo River-Woodbury Creek valley-fill 

aquifer system 

Till—Unsorted, unstratified mixture of clay, silt, sand, gravel, and boulders deposited beneath the ice as lodgment till during a glacial 

advance or at the edge of the ice sheet by melting ice as ablation till during a pause, or retreat, of the ice front. Very low permeability, but 

may yield adequate amounts of water for domestic use to large-diameter dug wells where sufficiently saturated or where gravelly zones of 

higher permeability exist

Bedrock—Description from drillers’ well logs. If rock type is not indicated in well logs, “r” is used. If rock type is indicated, an abbreviation in 

parentheses follows. Abbreviations are as follows: Ss., sandstone; Sh., shale; Ls., limestone; Gran., granite. “Gneiss” is not abbreviated

Horizontal-to-vertical (H/V) passive seismic survey site—Dashed line indicates estimated depth to bedrock. “no estimate” indicates that a 

measurement was made but site conditions prevented estimation of overburden thickness

Well—Label is well identification number assigned by the U. S. Geological Survey (USGS). Horizontal line and text indicates reported depth 

to groundwater from top of casing (from drillers’ well log) 

Test boring—Test boring used to define subsurface characteristics for engineering construction properties; no casing installed. Label is well 

identification number assigned by the USGS 

lsc

lss

t

r

30 feet

O3751

H/V

O1405

al

alf

af

osg

ic
Figure 3 17

300

350

400

450

500

550

600

650

r (Gneiss)

Fault

silt

VERTICAL EXAGGERATION x5

A A’

WEST EAST

0 500 1,000 FEET

0 125 250 METERS

FEET

DATUM IS NAVD 88

Ramapo River

H/V af

af ic

lss

H/V

al

O9593

ic

O1406

O1407

O1405

O1404

50 feet

Figure 3. Hydrogeologic section A–A’ at Arden, Orange County, New York.
18 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

0 1,000 FEET 5000 250 METERS 125

VERTICAL EXAGGERATION x10

r (Ls.)

r (Ls.)

r (Ls.)

r (Ls.)

r (Ls.)

r (Sh., Ss.)

t

t

t

Mountain Lakes

Ramapo River

80 feet

36 feet 28 feet

ND 25 feet

34 feet

TO 58 FEET ELEVATION

TO 140 FEET ELEVATION

700600500400300

O4083

O6547

O2465

O2466

O2468

O6589

osg osg

al

B B’

NORTH SOUTH

al

al

FEET

DATUM IS NAVD 88

Figure 4. Hydrogeologic section B–B’ at Harriman, Orange County, New York.
Figure 5 19

EAST

TO -30 FEET

VERTICAL EXAGGERATION x5

noestimate

no

estimate

C C’

WEST

lsc

lss

ic

ic

r (Ls., Sh.)

lsc?

t

t

O4775

Woodbury Creek

O1868

O1864

r (Ss.)

r (Ls?)

H/V

H/V

H/V

24 feet

25 feet

Flows

700600500400300200

Fault

TO 90 FEET

O1431

O1433

lsc? coarse 

sand

al Flows

r

r

FEET

0 1,000 FEET 5000 250 METERS 125

DATUM IS NAVD 88

Figure 5. Hydrogeologic section C–C’ at Woodbury, Orange County, New York.
20 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York VERTICAL EXAGGERATION x10 30 feet 20 feet 20 feet ND 30 feet 25 feet 122 feet 25 feet

0

500400300200100

r (Gran.)

r (Ls.?) r (Ss.) r (Sh.)

r (Sh.)

r (Sh.)

al

t

osg 

ic?

t

af

Woodbury Creek af

O3303

O3218

O3751

O6207

O8183

O2458

O2663

O7164

ic

D D’

WEST EAST

t

TO -65 FEET ELEVATION

TO -60 FEET ELEVATION

FEET

DATUM IS NAVD 88

0 1,000 FEET 500

0 250 METERS 125

Figure 6. Hydrogeologic section D–D’ at Mountainville, Orange County, New York.
Appendix 21

Appendixes 1–2
22 Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas, New York

Appendix 1. Well Data for the Ramapo River-Woodbury Creek Valley and 

Adjacent Uplands, Eastern Orange County, New York (http://dx.doi.org/10.3133/

sir20145156)
Appendix 2. North-south longitudinal section along Ramapo River-Woodbury Creek valleys showing elevations of floodp lains, terraces, and other valley-bottom 

glacial features. (http://dx.doi.org/10.3133/sir20145156) 

Appendix 2 23

NORTH AMERICAN VERTICAL DATUM OF 1988

FEET

700600500400300200100

Terrace at base of alluvial fan below south end of Lake Strahane (east side of valley)

Terrace

Low terrace

Terrace remnantat Southfilelds

Terrace at valleyconstriction

High terrace nearoutwash head

Bedrockknoll

Ice- contactdeposits

Till at divide (partly excavated)

Arden Tuxedo Park Harriman

Till in valley

Kame terrace

Kame delta

(likely thin sand and gravel over till )

Woodbury Falls

Quarry and former gravel pit

Till over sand and gravel

Highland Mills Mountainville

Excavated alluvial fan

Sand and gravel over till

Variable till and 

?

ice-contact sediments

Falls north of Tuxedo Kame 

terrace

?

South North

Terrace levels

Southfields

Present-day flood plain

Topographic featuresabove flood plain

Note: Offsets in profiles reflect profile segments that cross the valley and thus have a longer trace than the valley.

Geographic reference points (see figure 1A)

Projected proglacial lake level

0

2 KILOMETERS

1 2 MILES

0 1

Location map 

Profile traces—colors correspond to those in section

Study area boundary

A A’

NEW YORK NEW JERSEY

ORANGE COUNTY ROCKLAND COUNTY

Publishing support provided by the Pembroke and Rolla 

Publishing Service Centers.

For more information concerning this report, contact:

Director

New York Water Science Center

U.S. Geological Survey

425 Jordan Road

Troy, NY 12180-8349

dc_ny@usgs.gov

or visit our Web site at:

http://ny.water.usgs.gov
Heisig—Hydrogeology of the Ramapo River-Woodbury Creek Valley-Fill Aquifer System and Adjacent Areas in Eastern Orange County, New York—Scientific Investigations Report 2014–5156

ISSN 2328-0328 (online)

http://dx.doi.org/10.3133/sir20145156