Data Series 1075

Prepared in cooperation with the 

New York City Department of Environmental Protection

Groundwater-Level Data From an Earthen Dam Site

in Southern Westchester County, New York

U.S. Department of the Interior

U.S. Geological Survey

DATE

Water level, in feet above NGVD 29 226

228

230

232

234

236

238

240

242

244

246

248

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Cover (clockwise). U.S. Geological Survey (USGS) 7.5-minute (1:24,000-scale) topographic map of 

Mount Vernon, New York; from The National Map. 

Welcome sign posted at an earthen dam site in Westchester County, New York; photograph by 

Michael L. Noll, USGS.

USGS scientist downloading data from a water level recorder; photograph by Simonette Rivera, USGS.

Hydrograph for observation well TB–5S from an earthen dam site in Westchester County, New York, 

showing data from 2005 to 2016.
Groundwater-Level Data From an Earthen 

Dam Site in Southern Westchester County, 

New York

By Michael L. Noll and Anthony Chu

Prepared in cooperation with the 

New York City Department of Environmental Protection

Data Series 1075

U.S. Department of the Interior

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

RYAN K. ZINKE, Secretary

U.S. Geological Survey

William H. Werkheiser, Deputy Director

 exercising the authority of the Director

U.S. Geological Survey, Reston, Virginia: 2018

For more information on the USGS—the Federal source for science about the Earth, its natural and living 

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Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials 

as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.

Suggested citation:

Noll, M.L., and Chu, A., 2018, Groundwater-level data from an earthen dam site in southern Westchester County, 

New York: U.S. Geological Survey Data Series 1075, 35 p., https://doi.org/10.3133/ds1075.

ISSN 2327-0271 (print)

ISSN 2327-638X (online)

ISBN 978-1-4113-4200-2
iii

Acknowledgments

The authors thank Richard Zunino, Will Melendez, and Masud Ahmed of the New York City 

Department of Environmental Protection for their technical assistance and logistical support and 

for their cooperation in providing timely information on reservoir operations and construction to 

ensure successful U.S. Geological Survey field efforts. The authors also thank William Capurso, 

Peter Joesten, and Michael D. Como of the U.S. Geological Survey for their technical support 

during hydrologic data collection.

v

Contents

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

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

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

Groundwater-Level Measurements............................................................................................................6

Data Dissemination........................................................................................................................................6

References Cited............................................................................................................................................6

Appendix 1. Discrete and Continuous-Record Groundwater-Level Measurements for 

Observation Wells in Bronx and Westchester Counties, New York ......................................35

Figures

1. Map showing location of the Hillview Reservoir study area and selected

observation wells in Westchester County, New York.............................................................2

2. Map showing location of observation wells on the southern embankment at

the Hillview Reservoir in Westchester County, New York .....................................................3

3–52. Graphs showing discrete and continuous-record groundwater-level measurements 

for observation wells from an earthen dam site in southern Westchester County, 

New York:

3. Observation well B–77......................................................................................................10

4. Observation well TB–1S ...................................................................................................10

5. Observation well TB–1D...................................................................................................11

6. Observation well TB–2S ...................................................................................................11

7. Observation well TB–2D...................................................................................................12

8. Observation well TB–3D...................................................................................................12

9. Observation well TB–4S ...................................................................................................13

10. Observation well TB–4D...................................................................................................13

11. Observation well TB–5S ...................................................................................................14

12. Observation well TB–5D...................................................................................................14

13. Observation well TB–8......................................................................................................15

14. Observation well TB–9......................................................................................................15

15. Observation well TB–10....................................................................................................16

16. Observation well TB–11B.................................................................................................16

17. Observation well TB–12....................................................................................................17

18. Observation well TB–13....................................................................................................17

19. Observation well TB–14D.................................................................................................18

20. Observation well TB–15....................................................................................................18

21. Observation well TB–16....................................................................................................19

22. Observation well TB–17S .................................................................................................19

23. Observation well TB–17D.................................................................................................20

24. Observation well TB–18S .................................................................................................20

25. Observation well TB–18D.................................................................................................21

26. Observation well MB–4W ................................................................................................21

27. Observation well MB–5 ....................................................................................................22
vi

28. Observation well MR–100P..............................................................................................22

29. Observation well MR–100PA............................................................................................23

30. Observation well MR–121.................................................................................................23

31. Observation well MR–123P..............................................................................................24

32. Observation well MR–123PA............................................................................................24

33. Observation well MR–131.................................................................................................25

34. Observation well B–3P......................................................................................................25

35. Observation well B–4........................................................................................................26

36. Observation well B–5A .....................................................................................................26

37. Observation well HESF–8S...............................................................................................27

38. Observation well HESF–8D...............................................................................................27

39. Observation well CMB–2W..............................................................................................28

40. Observation well 104–P ....................................................................................................28

41. Observation well 104–PA..................................................................................................29

42. Observation well 105–P ....................................................................................................29

43. Observation well 106–P ....................................................................................................30

44. Observation well 109–P ....................................................................................................30

45. Observation well Y–PA......................................................................................................31

46. Observation well Y–PD .....................................................................................................31

47. Observation well Z–PA......................................................................................................32

48. Observation well Z–PD .....................................................................................................32

49. Observation well PD..........................................................................................................33

50. Observation well DT–2......................................................................................................33

51. Observation well WE–5078...............................................................................................34

52. Observation well WE–5079...............................................................................................34

Table

1. Site information for observation wells at Hillview Reservoir in Westchester County,

New York ........................................................................................................................................4
vii

Conversion Factors

U.S. customary units to International System of Units

Multiply By To obtain

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

acre 0.004047 square kilometer (km2)

gallon (gal) 3.785 liter (L)

pound, avoirdupois (lb) 0.4536 kilogram (kg)

pound per square inch (lb/in2) 6.895 kilopascal (kPa)

Datum

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

(NGVD 29).

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

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

Abbreviations

NYCDEP New York City Department Environmental Protection

USGS U.S. Geological Survey

Groundwater-Level Data From an Earthen Dam Site in 

Southern Westchester County, New York

By Michael L. Noll and Anthony Chu

Abstract

In 2005, the U.S. Geological Survey began a cooperative study with New York City Department of Environmental 

Protection to characterize the local groundwater-flow system and identify potential sources of seeps on the southern 

embankment of the Hillview Reservoir in Westchester County, 

New York. Groundwater levels were collected at 49 wells at 

Hillview Reservoir, and 1 well in northern Bronx County, 

from April 2005 through November 2016. Groundwater levels 

were measured discretely with a chalked steel or electric tape, 

or continuously with a digital pressure transducer, or both, 

in accordance with U.S. Geological Survey groundwatermeasurement standards. These groundwater-level data were 

plotted as time series and are presented in this report as hydrographs. Twenty-eight of the 50 hydrographs have continuous 

record and discrete field groundwater-level measurements, 

22 of the hydrographs contain only discrete measurements.

Introduction

The Hillview Reservoir (fig. 1) in southern Westchester 

County, New York, which was constructed between 1913 and 

1916, contains more than 900 million gallons of water and 

maintains a hydrostatic head of about 293 feet (ft) on the New 

York City water distribution system to the south. Most of the 

water used in New York City passes through the Hillview Reservoir facility from the Kensico Reservoir, which is fed by the 

Delaware and Catskill aqueducts in upstate New York. Water 

is chlorinated at the reservoir and is piped from the southern 

end of the reservoir for distribution to users in New York City. 

The 90-acre reservoir, which is partly lined by concrete, is 

about equally divided into the East Basin and West Basin by a 

concrete-dividing wall. It has operated continuously since the 

first water tunnel was completed in 1917.

The earthen embankment comprises highly compact, 

low-permeability glacial clays that were excavated from the 

site and rest on a veneer of low-permeability glacial till that 

overlie crystalline bedrock (New York City Department of 

Environmental Protection, 1909; Malcolm Pirnie, Inc. and 

TAMS Consultants, Inc., 2002). The earthen embankment was 

subsequently modified by other construction and maintenance 

projects near the downtake, uptake, and control chambers; 

connecting shafts; connecting conduits; the reservoir dividing 

wall; and the bypass tunnel that are critical to reservoir operations (fig. 2).

From April 2005 through November 2016, the U.S. Geological Survey (USGS), in cooperation with the New York 

City Department of Environmental Protection, collected 

hydraulic-head data (groundwater levels) at 49 wells at 

Hillview Reservoir and 1 well in northern Bronx County. 

The principal objectives of this study were to characterize the 

distribution of groundwater levels near the reservoir to better 

understand the embankment groundwater-flow system, characterize possible flow paths of water to the seeps, and monitor 

the long- and short-term changes in groundwater levels and 

seep discharge within the study area.

Groundwater-level data from the 50 wells that were 

monitored during the project are shown in hydrographs in 

this report (figs. 3–52) and can be retrieved from the USGS 

National Water Information System (U.S. Geological Survey, 

2016) by using the USGS site identifiers in table 1. These data 

are also available in tabular format in appendix 1.

Groundwater generally flows or seeps outward from 

the reservoir through the low-permeability embankment 

toward the surrounding glacial drift. Since 1999, several 

seeps downslope from the East Basin have flowed out from 

the western side of the southern embankment, which is the 

steepest slope at the Hillview Reservoir (fig. 2). One seep that 

flowed continuously during the study was discovered during 

an inspection of the embankment in 1999 (George Schmitt, 

New York City Department of Environmental Protection, 

written commun., 2007). In 2001, the New York City 

Department of Environmental Protection (NYCDEP) drilled 

25 wells at the southern end of the reservoir, adding to the 

32 wells previously installed around the reservoir in an effort 

to locate the potential sources of the continuous flowing seep. 

The NYCDEP approach included taking periodic depth-towater measurements and sampling reservoir and spring water 

for major ions (Malcolm Pirnie, Inc. and TAMS Consultants, 

Inc., 2002).
2 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

Base derived from Google Earth, 2017

Transverse Mercator projection

State Plane New York East FIPS 3101

North American Datum of 1983

KIMBALL AVENUE

HILLVIEW AVENUE

CENTRAL PARK AVENUE

HARDING AVENUE

NEW YORK STATE THRUWAY

EXTENT OF FIGURE 2

EAST

BASIN

WEST

BASIN Basin 

dividing 

wall

BRONX COUNTY

WESTCHESTER COUNTY

WE–5078

PA

PD

111

B–77

Z–PD

Z–PA

Y–PD

Y–PA

DT–2

104–P

109–P

106–P

MR–131 105–P

106–PA

104–PA

HESF–8D

HESF–8S

WE–5079

73°52'30" 73°52'

40°55'

40°54'30"

X

110–P

Kensico 

Reservoir

Delaware Aqueduct

Catskill Aqueduct

Map 

Area

ROCKLAND

COUNTY

NEW

JERSEY

NEW YORK

COUNTY

NASSAU

COUNTY

BRONX

COUNTY

WESTCHESTER

COUNTY

LONG ISLAND SOUND

Hudson River

Extent of earthen dam 

EXPLANATION

Observation well and identifier

106-P

Building

0 150 300 FEET

0 150 300 METERS

Van Cortland Park

Figure 1. Location of the Hillview Reservoir study area and selected observation wells in Westchester County, 

New York.
Introduction 3

Base derived from Google Earth, 2017

Transverse Mercator projection

State Plane New York East FIPS 3101

North American Datum of 1983

73°52'10" 73°52'

40°54'30"

40°54'25" HILLVIEW AVENUE

KIMBALL AVENUE

EAST

BASIN

MR–100PA

B–4

TB–9

TB–8

MB–5

B–5A

B–3P

TB–3S TB–16

MB–1W

TB–2S

TB–5S

TB–5D

TB–4S

TB–4D

TB–3D

TB–2D

TB–1D TB–1S

TB–15

TB–13

TB–12

TB–10

MB–4W

TB–14S

TB–18S

TB–18D

TB–17S

TB–17D

TB–14D

TB–11B

MR–121

CMB–2W

MR–100P

MR–123PA

MR–123P

Downtake 

chamber 1

Downtake 

chamber 2

Control 

chamber

Chlorination 

building

South connecting conduit

Extent of earthen dam 

EXPLANATION

Observation well and identifier

TB–13

Building 

0 50 100 FEET

0 50 100 METERS

Figure 2. Location of observation wells on the southern embankment at the Hillview Reservoir in Westchester County, 

New York.
4 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

Table 1. Site information for observation wells at Hillview Reservoir in Westchester County, New York.

[Altitudes are in feet above the National Geodetic Vertical Datum of 1929. Depths are in feet below land surface. Latitude and longitude are referenced to the 

North American Datum of 1983. NYSDEC, New York State Department of Environmental Conservation; ID, identifier; USGS, U.S. Geological Survey; ft, foot; 

—, no data; D, discrete measurements only; DC, discrete and continuous-record measurements]

Local well 

name

NYSDEC 

well ID

LongitudeLatitude USGS site ID

Measuring point 

altitude

(ft)

Land 

surface 

altitude

(ft)

Well 

depth

(ft)

Sounded 

depth

(ft)

Screen 

depth

(ft)

Saturated zone 

screened

Water 

level 

measurement type

Figure 

number

B–77a B77 –735209 405408 405408073520901 189.35 190.00 21 20.7 16–21 — DC 1

TB–1S WE5051 –735210 405428 405428073520901 302.01 300.69 40 41.8 30–40 Shallow DC 2

TB–1D WE5062 –735210 405428 405428073520902 302.37 300.49 122 72.05 60–70 Deep DC 2

TB–2S WE5058 –735206 405427 405428073520302 300.23 299.73 41 38.45 30–40 Shallow DC 2

TB–2D WE5072 –735209 405427 405427073520802 300.23 300.16 71 67.45 60–70 Deep DC 2

TB–3S WE5032 –735207 405427 405426073520701 300 300.28 41 39.5 30–40 Shallow — 2

TB–3D WE5057 –735207 405427 405426073520702 300.2 300.29 71 62.2 60–70 Deep D 2

TB–4S WE5039 –735205 405427 405427073520401 302.79 300.29 — 43.3 — Shallow DC 2

TB–4D WE5045 –735205 405427 405427073520402 302.46 300.05 103 73.1 60–70 Deep DC 2

TB–5S WE5024 –735210 405426 405426073521002 300.92 299.17 51 50.9 30–40 Shallow DC 2

TB–5D WE5071 –735210 405426 405426073521004 301.13 299.03 77 76.15 66–76 Deep DC 2

TB–8 WE5040 –735204 405425 405425073524001 276.87 275.14 42 42.1 29–39 Shallow D 2

TB–9 WE5043 –735204 405425 405424073520501 268.63 269.03 41 42.2 30–40 Toe D 2

TB–10 WE5050 –735204 405423 405423073520401 245.44 243.39 41 42.35 20–40 Toe DC 2

TB–11B WE5048 –735203 405425 405425073520201 255.85 253.46 31 31.7 20–30 Shallow DC 2

TB–12 WE5035 –735203 405427 405424073520301 249.27 247.11 52 32.1 20–30 Toe DC 2

TB–13 WE5033 –735210 405424 405423073521001 220.66 217.97 31 32.4 30–Oct Toe DC 2

TB–14S WE5028 –735205 405422 405422073520501 241.45 238.9 48 — 20–30 Toe — 2

TB–14D WE5041 –735205 405422 405422073520502 242.97 240.54 50 50.9 29–49 Toe DC 2

TB–15 WE5046 –735212 405426 405426073521201 229.77 227.95 33 30.17 12–32 Toe DC 2

TB–16 WE5027 –735210 405427 405427073521001 299.33 299.75 49 48.75 — — D 2

TB–17S WE5022 –735211 405427 405426073521001 299 297.32 40 39.9 30–40 Shallow DC 2

TB–17D WE5063 –735211 405427 405426073521003 299.2 297.37 80 79.75 70–80 Deep DC 2

TB–18S WE5056 –735212 405428 405427073521102 277.99 275.32 27 26.8 — Shallow DC 2

TB–18D WE5049 –735212 405428 405427073521101 278.02 275.43 60 63.55 50–60 Deep DC 2

MB–1W WE5065 –735212 405430 405430073521101 300.38 300.55 107 77 60–80 — — 2

MB–4W WE5069 –735213 405430 405429073521201 288.31 286.82 103 61.5 50–60 Deep DC 2

MB–5 WE5070 –735211 405428 405427073521103 299.31 299.67 105 75.25 60–80 Deep DC 2

MR–100P WE5042 –735210 405428 405427073520901 300.71 299.02 — 39.45 — Shallow DC 2

MR–100PA WE5066 –735208 405428 405427073520902 300.88 298.96 — 61.35 — Deep DC 2

MR–121 WE5067 –735202 405427 405427073520102 265.19 262.33 — 20.5 — Shallow D 2

MR–123P WE5068 –735204 405428 405427073520801 302.49 299.73 — 38.9 — Deep D 2

MR–123PA WE5031 –735204 405428 405428073520301 302.06 299.35 — 19.6 — Shallow D 2

MR–131 WE5074 –735222 405440 405439073522101 273.2 270.6 33 32.55 — — D 1

B–3P WE5026 –735206 405427 405426073520501 299.79 300.53 — 22.55 — Shallow D 2

B–4 WE5060 –735206 405426 405425073520502 283.81 282.15 — 35.67 — Shallow D 2

B–5A WE5055 –735206 405425 405425073520501 279.45 277.35 — 35.45 — Shallow D 2

HESF–8S WE5037 –735228 405443 405442073522801 243.88 241.78 10 10.7 5–10 Shallow D 1

HESF–8D WE5029 –735228 405443 405442073522701 244.15 241.81 19 19.3 14–19 Deep D 1

CMB–2W WE5064 –735205 405427 405426073520502 301.03 299 — 35.4 — Shallow DC 2

104–P WE5059 –735217 405436 405436073521702 301.72 300 — 41.3 — — D 1

104–PA WE5047 –735217 405436 405436073521701 302.98 300 — 20.7 — — D 1
Introduction 5

Table 1. Site information for observation wells at Hillview Reservoir in Westchester County, New York.—Continued

[Altitudes are in feet above the National Geodetic Vertical Datum of 1929. Depths are in feet below land surface. Latitude and longitude are referenced to the 

North American Datum of 1983. NYSDEC, New York State Department of Environmental Conservation; ID, identifier; USGS, U.S. Geological Survey; ft, foot; 

—, no data; D, discrete measurements only; DC, discrete and continuous-record measurements]

Local well 

name

NYSDEC 

well ID

LongitudeLatitude USGS site ID

Measuring point 

altitude

(ft)

Land 

surface 

altitude

(ft)

Well 

depth

(ft)

Sounded 

depth

(ft)

Screen 

depth

(ft)

Saturated zone 

screened

Water 

level 

measurement type

Figure 

number

105–P WE5053 –735220 405441 405440073522001 302.65 300.7 — 42.65 — — D 1

106–P WE5061 –735224 405444 405444073522301 301.2 298.9 — 42.4 — — DC 1

106–PA WE5054 –735224 405444 405444073522401 301.33 296.6 — 42.62 — — — 1

109–P WE5073 –735223 405454 405454073522201 303.1 300.1 — 34.75 — — D 1

110–P WE5034 –735220 405458 405458073521901 303.4 302.1 — 32.65 — — — 1

111 — –735215 405502 — — — — — — — — 1

X WE5021 –735209 405459 405458073520901 302.1 299.9 — 38.35 — — — 1

Y–PA WE5030 –735207 405454 405454073520701 302.63 300 — 21.14 — — D 1

Y–PD WE5044 –735207 405454 405454073520702 302.45 300 — 42.4 — — D 1

Z–PA WE5036 –735203 405445 405445073520201 302.75 300.4 — 19.86 — — DC 1

Z–PD WE5052 –735203 405445 405445073520202 302.06 299.4 — 46.12 — — DC 1

PA WE5038 –735159 405432 405432073515801 303.17 300.3 — 22.05 — — — 1

PD WE5023 –735159 405437 405436073515801 302.76 300.2 — 42.3 — — D 1

DT–2 WE5025 –735212 405503 405502073521101 300.9 298.92 — 44.8 — — DC 1

WE–5078 WE5078 –735157 405441 405441073515701 290.6 287.6 124 124.2 — — D 1

WE–5079 WE5079 –735201 405449 405449073520001 277.58 274.6 91 91.15 — — D 1

a

Well B–77 is in Bronx County.
6 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

In 2005, the U.S. Geological Survey (USGS) began 

a cooperative study with the NYCDEP to investigate the 

relevant hydrogeologic framework to characterize the local 

groundwater-flow system and to determine possible sources of 

the seeps (Chu and others, 2013). In August 2011, the USGS 

drilled one additional well, B–77 (fig. 1; table 1), south of the 

reservoir in Van Cortland Park in Bronx County to supplement 

the existing 57-monitoring-well network. The USGS was able 

to access 50 of the 58 wells for monitoring groundwater levels.

Groundwater-Level Measurements

Discrete and continuous-record groundwater levels 

were collected at 50 of the 58 wells from April 2005 through 

November 2016 (fig. 1; table 1). Groundwater-level data were 

not collected from eight sites (TB–3S, TB–14S, MB–1W, 

106–PA, 110–P, 111, X, and PA) in the monitoring network 

because these wells were decommissioned, damaged, or 

destroyed before the beginning of the study. Groundwaterlevel records are incomplete for wells HESF–8D, HESF–8S, 

MR–131, Y–PA, and 104–P because they were destroyed 

during various construction projects at the reservoir during the 

study period (figs. 3 through 52, in back of report). To supplement the existing monitoring network and replace damaged 

or destroyed wells, MR–123P, MR–123PA, PD, and Y–PD 

were repaired during the study period so groundwater levels 

could be collected. For some wells, such as TB–16, TB–18S, 

and B–77, water levels occasionally dropped below the bottom of the well screen; these measurements were recorded 

as “dry” in the National Water Information System (NWIS) 

database (U.S. Geological Survey, 2016) and are not shown 

on the hydrographs in figures 3 through 52 (in back of report). 

Throughout the study, the USGS measured groundwater levels 

on a monthly basis except when site access was limited or 

denied for legal or safety concerns. Episodic groundwater 

measurements were made at select wells during hydraulic testing, water-quality sampling, and other data-collection activities throughout the course of the study.

Water-level measurements were either taken manually 

with a chalked, graduated steel tape or a calibrated electric 

tape from the wellhead (measuring point) or calculated from 

pressure-transducer output that was recorded automatically 

by data loggers installed on select observation wells. Manual 

depth-to-water measurements were made in accordance with 

standard USGS procedures (Cunningham and Schalk, 2011). 

Depth-to-water measurements were converted to groundwaterlevel altitude values by subtracting the depth-to-water measurement from the wellhead altitude. Depth-to-water measurements using the steel tape or calibrated electric tape method 

are considered accurate to about 0.01 ft (Cunningham and 

Schalk, 2011).

Vented submersible pressure transducers were installed 

in 28 wells and were programmed to measure and record 

groundwater levels every 60 minutes. Data logged on these 

instruments were downloaded and corrected for instrument 

drift based on manual measurements of groundwater-level 

altitudes that were made from the wellhead measuring points 

during periodic field inspections from April 2005 through 

November 2016. The accuracy of a pressure transducer rated 

to 15 pounds per square inch (lb/in2) is approximately 0.05 ft 

(In-Situ Inc., 2015). Hydrographs were created from the 

continuous-record data (figs. 3 through 52, in back of report). 

Discrete field measurements are included in the hydrographs 

to verify the continuous-record measurements, and to provide 

data where continuous measurements are missing throughout the period of record. Twenty-eight of the 50 hydrographs 

in this report have both continuous record and discrete field 

groundwater-level measurements; the other 22 hydrographs 

contain only discrete measurements.

Data Dissemination

Discrete and continuous record groundwater-level data 

collected during this project are shown in hydrographs in 

the back of this report (figs. 3–52) and can be downloaded 

from the USGS National Water Information System 

(U.S. Geological Survey, 2016). These data have been 

replicated from the USGS National Water Information System 

in appendix 1 and can be downloaded in tabular format at 

https://doi.org/10.3133/ds1075.

References Cited

Chu, Anthony, Stumm, Frederick, Joesten, P.K., and Noll, 

M.L., 2013, Geophysical and hydrologic analysis of 

an earthen dam site in southern Westchester County, 

New York: U.S. Geological Survey Scientific Investigations Report 2012–5247, 64 p. [Also available at 

http://pubs.usgs.gov/sir/2012/5247/.]

Cunningham, W.L., and Schalk, C.W., comps., 2011, Groundwater technical procedures of the U.S. Geological Survey: 

U.S. Geological Survey Techniques and Methods, book 1, 

chap. A1, 151 p. [Also available at https://pubs.usgs.gov/

tm/1a1/.]

In-Situ Inc., 2015, Level Troll 500: In-Situ Inc. website, 

accessed June 16, 2015, at https://in-situ.com/products/

level-temp-data-loggers/level-troll-500-data-logger/.

Malcolm Pirnie, Inc., and TAMS Consultants, Inc., 2002, 

Capital project W–10, Hillview reservoir—Cover, phase I, 

dividing wall stability buttress construction; south embankment monitoring and leakage investigations: U.S. Environmental Protection Agency, 18 p.
References Cited 

7

New York City Department of Environmental Protection, 

1909, Board of Water Supply, Hillview Reservoir, con-

tract 30, May 15, 1909: New York City Department of 

Environmental Protection report, [unpaginated].

U.S. Geological Survey, 2016, Groundwater levels for the 

nation, in USGS water data for the nation: U.S. Geologi-

cal Survey National Water Information System database, 

accessed March 23, 2017, at https://doi.org/10.5066/

F7P55KJN. [Groundwater level data directly accessible at 

https://waterdata.usgs.gov/nwis/gw.]

Figures 3–52
10 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

B-77

Date

Water level, in feet above NGVD 29

166

168

170

172

174

176

178

180

182

184

186

188

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 3. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well B–77 from an 

earthen dam site in southern 

Westchester County, New York. 

Well B–77 is in Bronx County. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1

TB-1S

Date

Water level, in feet above NGVD 29

260

262

264

266

268

270

272

274

276

278

280

282

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 4. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–1S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 11

TB-1D

Date

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 5. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–1D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-2S

Date

Water level, in feet above NGVD 29

268

270

272

274

276

278

280

282

284

286

288

290

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 6. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–2S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
12 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

TB-2D

Date

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 7. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–2D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-3D

Date

Water level, in feet above NGVD 29

254

256

258

260

262

264

266

268

270

272

274

276

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 8. Discrete 

groundwater-level 

measurements for observation 

well TB–3D from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 13

TB-4S

Date

Water level, in feet above NGVD 29

254

252

256

258

260

262

264

266

268

270

272

274

276

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 9. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–4S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-4D

Date

Water level, in feet above NGVD 29

232

234

236

238

240

242

244

246

248

250

252

254

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 10. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–4D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
14 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

TB-5S

Date

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 11. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–5S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-5D

Date

Water level, in feet above NGVD 29

226

228

230

232

234

236

238

240

242

244

246

248

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 12. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–5D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 15

Date

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

TB-8

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Figure 13. Discrete 

groundwater-level 

measurements for observation 

well TB–8 from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-9

Date

Water level, in feet above NGVD 29

230

232

234

236

238

240

242

244

246

248

250

252

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 14. Discrete 

groundwater-level 

measurements for observation 

well TB–9 from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
16 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

TB-10

Date

Water level, in feet above NGVD 29

211

213

215

217

219

221

223

225

227

229

231

233

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 15. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–10 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-11B

Date

Water level, in feet above NGVD 29

234

236

238

240

242

244

246

248

250

252

254

256

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 16. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–11B from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 17

TB-12

Date

Water level, in feet above NGVD 29

220

222

224

226

228

230

232

234

236

238

240

242

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 17. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–12 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-13

Date

Water level, in feet above NGVD 29

182

184

186

188

190

192

194

196

198

200

202

204

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 18. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–13 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
18 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

TB-14D

Date

Water level, in feet above NGVD 29

196

198

200

202

204

206

208

210

212

214

216

218

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 19. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–14D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-15

Date

Water level, in feet above NGVD 29

210

212

214

216

218

220

222

224

226

228

230

232

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 20. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–15 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 19

TB-16

Date

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 21. Discrete 

groundwater-level 

measurements for observation 

well TB–16 from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-17S

Date

Water level, in feet above NGVD 29

252

254

256

258

260

262

264

266

268

270

272

274

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 22. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–17S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
20 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

TB-17D

Date

Water level, in feet above NGVD 29

230

232

234

236

238

240

242

244

246

248

250

252

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 23. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–17D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

TB-18S

Date

Water level, in feet above NGVD 29

250

252

254

256

258

260

262

264

266

268

270

272

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 24. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–18S from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 21

TB-18D

Date

Water level, in feet above NGVD 29

230

232

234

236

238

240

242

244

246

248

250

252

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 25. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well TB–18D from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

MB-4W

Date

Water level, in feet above NGVD 29

238

240

242

244

246

248

250

252

254

256

258

260

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 26. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well MB–4W from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
22 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

MB-5

Date

Water level, in feet above NGVD 29

240

242

244

246

248

250

252

254

256

258

260

262

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 27. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well MB–5 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

MR-100P

Date

Water level, in feet above NGVD 29

254

256

258

260

262

264

266

268

270

272

274

276

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 28. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well MR–100P from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 23

MR-100PA

Date

Water level, in feet above NGVD 29

236

238

240

242

244

246

248

250

242

254

256

258

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 29. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well MR–100PA from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

MR-121

Date

Water level, in feet above NGVD 29

244

246

248

250

252

254

256

258

260

262

264

266

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 30. Discrete 

groundwater-level 

measurements for observation 

well MR–121 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
24 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

MR-123P

Date

Water level, in feet above NGVD 29

256

258

260

262

264

266

268

270

272

274

276

278

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

MR-123PA

Date

Water level, in feet above NGVD 29

300

298

296

294

292

290

288

286

284

282

280

278

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 31. Discrete 

groundwater-level 

measurements for observation 

well MR–123P from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

Figure 32. Discrete 

groundwater-level 

measurements for observation 

well MR–123PA from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
Figures 3–52 25

MR-131

Date

Water level, in feet above NGVD 29

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

232

234

236

238

240

242

244

246

248

250

252

254

256

258

260

262

264

Manual water level

EXPLANATION

Figure 33. Discrete 

groundwater-level 

measurements for observation 

well MR–131 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

B-3P

Date

Water level, in feet above NGVD 29

274

276

278

280

282

284

286

288

290

292

294

296

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 34. Discrete 

groundwater-level 

measurements for observation 

well B–3P from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.
26 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

B-4

Date

Water level, in feet above NGVD 29

246

248

250

252

254

256

258

260

262

264

266

268

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 35. Discrete 

groundwater-level 

measurements for observation 

well B–4 from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

Figure 36. Discrete 

groundwater-level 

measurements for observation 

well B–5A from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

B-5A

Date

Water level, in feet above NGVD 29

238

240

242

244

246

248

250

252

254

256

258

260

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Figures 3–52 27

HESF-8S

Date

Water level, in feet above NGVD 29

224

226

228

230

232

234

236

238

240

242

244

246

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 37. Discrete 

groundwater-level 

measurements for observation 

well HESF–8S from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

HESF-8D

Date

Water level, in feet above NGVD 29

224

226

228

230

232

234

236

238

240

242

244

246

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 38. Discrete 

groundwater-level 

measurements for observation 

well HESF–8D from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
28 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

104-P

Date

Water level, in feet above NGVD 29

260

262

264

266

268

270

272

274

276

278

280

282

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

CMB-2W

Date

Water level, in feet above NGVD 29

274

276

278

280

282

284

286

288

290

292

294

296

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 39. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well CMB–2W from 

an earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 2; details are 

listed in table 1.

Figure 40. Discrete 

groundwater-level 

measurements for observation 

well 104–P from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
Figures 3–52 29

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

104-PA

Date

Water level, in feet above NGVD 29

278

280

282

284

286

288

290

292

294

296

298

300

Manual water level

EXPLANATION

Figure 41. Discrete 

groundwater-level 

measurements for observation 

well 104–PA from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

105-P

Date

Water level, in feet above NGVD 29

260

262

264

266

268

270

272

274

276

278

280

282

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 42. Discrete 

groundwater-level 

measurements for observation 

well 105–P from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
30 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

106-P

Date

Water level, in feet above NGVD 29

258

260

262

264

266

268

270

272

274

276

278

280

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 43. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well 106–P from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

109-P

Date

Water level, in feet above NGVD 29

278

280

282

284

286

288

290

292

294

296

298

300

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 44. Discrete 

groundwater-level 

measurements for observation 

well 109–P from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
Figures 3–52 31

Y-PA

Date

Water level, in feet above NGVD 29

278

280

282

284

286

288

290

292

294

296

298

300

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 45. Discrete 

groundwater-level 

measurements for observation 

well Y–PA from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

Y-PD

Date

Water level, in feet above NGVD 29

268

270

272

274

276

278

280

282

284

286

288

290

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 46. Discrete 

groundwater-level 

measurements for observation 

well Y–PD from an earthen dam 

site in southern Westchester 

County, New York. Gaps in 

groundwater-level record 

indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
32 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

Z-PA

Date

Water level, in feet above NGVD 29

278

280

282

284

286

288

290

292

294

296

298

300

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 47. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well Z–PA from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

Z-PD

Date

Water level, in feet above NGVD 29

260

262

264

266

268

270

272

274

276

278

280

282

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 48. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well Z–PD from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
Figures 3–52 33

PD

Date

Water level, in feet above NGVD 29

266

268

270

272

274

276

278

280

282

284

286

288

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 49. Discrete 

groundwater-level 

measurements for observation 

well PD from an earthen dam site 

in southern Westchester County, 

New York. Gaps in groundwaterlevel record indicate no data or 

a dry measurement. Location of 

well shown on figure 1; details 

are listed in table 1.

DT-2

Date

Water level, in feet above NGVD 29

260

262

264

266

268

270

272

274

276

278

280

258

Continuous water level

Discrete manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 50. Discrete and 

continuous-record groundwaterlevel measurements for 

observation well DT–2 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
34 Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York

WE-5078

Date

Water level, in feet above NGVD 29

236

238

240

242

244

246

248

250

252

254

256

258

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 51. Discrete 

groundwater-level 

measurements for observation 

well WE–5078 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.

WE-5079

Date

Water level, in feet above NGVD 29

236

238

240

242

244

246

248

250

252

254

256

258

Manual water level

EXPLANATION

04/0110/0104/0110/0104/01

10/01

04/0110/0104/0110/0104/0110/01

04/01

10/0104/0110/0104/01

10/01

04/01

10/01

04/01

10/0104/0110/0104/01

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Figure 52. Discrete 

groundwater-level 

measurements for observation 

well WE–5079 from an 

earthen dam site in southern 

Westchester County, New York. 

Gaps in groundwater-level 

record indicate no data or a dry 

measurement. Location of well 

shown on figure 1; details are 

listed in table 1.
Appendix 1 35

Appendix 1. Discrete and Continuous-Record Groundwater-Level 

Measurements for Observation Wells in Bronx and Westchester Counties, 

New York

The data in tables 1.1 through 1.50 are replicated from the U.S. Geological Survey National Water Information System (U.S. Geological Survey, 2016) and can be downloaded at https://doi.org/10.3133/ds1075.

For more information about this report, contact:

Director, New York Water Science Center

U.S. Geological Survey

2045 Route 112, Building 4

Coram, NY 11727

dc_ny@usgs.gov

(518) 285–5602

or visit our website at

https://ny.water.usgs.gov

Publishing support provided by the 

Pembroke Publishing Service Center
Noll and Chu—Groundwater-Level Data From an Earthen Dam Site in Southern Westchester County, New York—Data Series 1075

Printed on recycled paper

ISSN 2327-0271 (print)

ISSN 2327-638X (online)

https://doi.org/10.3133/ds1075