U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2017–5153

Prepared in cooperation with the U.S. Environmental Protection Agency, 

Great Lakes Restoration Initiative

Water Pressure and Ground Vibrations Induced by Water 

Guns near Brandon Road Lock and Dam and Lemont, Illinois
Cover: Photograph showing water gun and hydrophone boom setup at Brandon Road 

Lock and Dam near Lemont, Illinois. Photograph by Carolyn Koebel, U.S. Geological 

Survey, May 2014.
Water Pressure and Ground Vibrations 

Induced by Water Guns near Brandon 

Road Lock and Dam and Lemont, Illinois

By Ryan F. Adams, Carolyn M. Koebel, and William S. Morrow

Prepared in cooperation with the U.S. Environmental Protection Agency, 

Great Lakes Restoration Initiative

Scientific Investigations Report 2017–5153

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

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

Suggested citation:

Adams, R.F., Koebel, C.M., and Morrow, W.S., 2018, Water pressure and ground vibrations induced by water 

guns near Bandon Road Lock and Dam and Lemont, Illinois: U.S. Geological Survey Scientific Investigations 

Report 2017–5153, 55 p., https://doi.org/10.3133/sir20175153.

ISSN 2328-0328 (online)
iii

Contents

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

Introduction.....................................................................................................................................................2

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

Brandon Road Test Area Description................................................................................................2

Lemont Test Area Description ............................................................................................................2

Methods...........................................................................................................................................................4

Equipment...............................................................................................................................................5

Brandon Road Study ............................................................................................................................6

Varying Gun Distance Scenario ................................................................................................9

Single Gun Radial Scenario .......................................................................................................9

Static Boom High Pressure Scenario.......................................................................................9

Double Gun Radial Scenario......................................................................................................9

Lemont Study.........................................................................................................................................9

2011 Replicate Scenario ...........................................................................................................10

Double Gun Grid Scenario........................................................................................................13

Results for Water Pressure and Ground Vibrations...............................................................................13

Brandon Road Water Pressure ........................................................................................................13

Varying Gun Distance Scenario ..............................................................................................13

Single Gun Radial Scenario .....................................................................................................13

Static Boom High Pressure Scenario.....................................................................................13

Double Gun Radial Scenario....................................................................................................23

Brandon Road Ground Vibrations ....................................................................................................27

Varying Gun Distance Scenario ..............................................................................................27

Other Scenarios .........................................................................................................................28

Acceleration ...............................................................................................................................30

Lemont Water Pressure.....................................................................................................................30

2011 Replicate Scenario ...........................................................................................................30

Double Gun Grid Scenario........................................................................................................32

Lemont Ground Vibrations.................................................................................................................44

2011 Replicate Scenario ...........................................................................................................44

Double Gun Grid Scenario........................................................................................................46

Acceleration ...............................................................................................................................49

Comparison of Hydrophone Data from Different Water-Gun Configurations....................................50

Summary........................................................................................................................................................54

Acknowledgments.......................................................................................................................................54

References Cited .........................................................................................................................................55
iv

Figures

1. Water gun firing schematic ........................................................................................................2

2. Map showing location of study area and major sensor groups, Des Plaines River,

near Joliet, Illinois ........................................................................................................................3

3. Map showing location of Lemont water gun test and data collection areas, 

Chicago Sanitary Ship Channel, near Lemont, Illinois............................................................4

4. Graph showing velocities of near and far Instantel® and near and far R.T. Clark

surface geophone pairs from a 2,000-pound-per-square-inch shot located 50 feet

from canal wall..............................................................................................................................5

5. Image showing water gun, geophone, and accelerometer positions for varying gun

distance scenario, Brandon Road study, Des Plaines River, near Joliet, Illinois...............7

6. Image showing water gun, geophone, and accelerometer positions for single gun

radial scenario, Brandon Road study, Des Plaines River, near Joliet, Illinois....................7

7. Image showing water gun, geophone, and accelerometer positions for static boom

high pressure scenario, Brandon Road study, Des Plaines River, near Joliet, Illinois .....8

8. Image showing water gun, geophone, and accelerometer positions for double gun

radial scenario, Brandon Road study, Des Plaines River, near Joliet, Illinois....................8

9. Cross-sectional schematic diagram and plan view of 2011 replicate scenario,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................11

10. Cross-sectional schematic diagram inset, and plan views of double gun grid high

pressure and low pressure scenarios, Chicago Sanitary Ship Channel, near

Lemont, Illinois ............................................................................................................................12

11. Graph showing effects of equipment malfunction on waveform data from a single

hydrophone, Brandon Road study, Des Plaines River, near Joliet, Illinois .......................14

12. Graph showing pressure data from a hydrophone placed 1 foot from testing wall 

at depth of 8 feet below water surface, Brandon Road study, Des Plaines River, 

near Joliet, Illinois ......................................................................................................................15

13. Map showing pressure measurements at water surface from a single

80-cubic-inch water gun fired at 700 pounds per square inch, Brandon Road 

study, Des Plaines River, near Joliet, Illinois..........................................................................15

14. Map showing pressure measurements at a depth of 2 feet below water surface

from a single 80-cubic-inch water gun fired at 700 pounds per square inch,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................16

15. Map showing pressure measurements at a depth of 4 feet below water surface

from a single 80-cubic-inch water gun fired at 700 pounds per square inch,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................17

16. Map showing pressure measurements at a depth of 6 feet below water surface

from a single 80-cubic-inch water gun fired at 700 pounds per square inch,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................18

17. Map showing pressure measurements at a depth of 8 feet below water surface

from a single 80-cubic-inch water gun fired at 700 pounds per square inch,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................19

18. Map showing pressure measurements at a depth of 9 feet below water surface

from a single 80-cubic-inch water gun fired at 700 pounds per square inch,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................20

19. Profiles showing spatial distribution of pressure for a single 80-cubic-inch water

gun placed 55 feet from the testing wall, 6 feet below the water surface, and fired

at 1,000 , 1,500, and 2,000 pounds per square inch, Brandon Road study, Des Plaines

River, near Joliet, Illinois ...........................................................................................................21
v

20. Profiles showing spatial distribution of pressure for single 80-cubic-inch water

guns placed 6 feet below water surface and 8 feet below water surface oriented

orthogonally to the first water gun, and for two 80-cubic-inch water guns placed 

6 and 8 feet below water surface, respectively, all 55 feet from the testing wall 

and fired at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, 

near Joliet, Illinois ......................................................................................................................22

21. Profiles showing spatial distribution of pressure for a single 80-cubic-inch water

gun 6 feet below water surface, and for two 80-cubic-inch water guns 6 and 

8 feet below water surface, all 55 feet from the testing wall and fired at a

pressure of 2,000 pounds per square inch, Brandon Road study, Des Plaines 

River, near Joliet, Illinois ...........................................................................................................23

22. Map showing pressure measurements at water surface from two 80-cubic-inch

water guns fired at 1,000 pounds per square inch, Brandon Road study, Des Plaines

River, near Joliet, Illinois ...........................................................................................................24

23. Map showing pressure measurements at a depth of 2 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................24

24. Map showing pressure measurements at a depth of 4 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................25

25. Map showing pressure measurements at a depth of 6 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................25

26. Maps showing pressure measurements at a depth of 8 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................26

27. Map showing Pressure measurements at a depth of 9 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................26

28. Profiles showing spatial distribution of pressure for a single 80-cubic-inch water

gun 6 feet below water surface fired at 700 pounds per square inch, and for two

80-cubic-inch water guns 6 and 8 feet below water surface fired at 1,000 pounds

per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.................27

29. Graph showing changes in velocity at geophones placed 6 and 16 feet from testing

wall in transverse, longitudinal, and vertical components, Brandon Road study, 

Des Plaines River, near Joliet, Illinois .....................................................................................28

30. Graphs showing changes in velocity with varying water gun pressure, Brandon

Road study, Des Plaines River, near Joliet, Illinois ...............................................................28

31. Graph showing transverse, longitudinal, and vertical wall velocities of pressure

waves from firing of two 80-cubic-inch water guns fired at 1,000 pounds per square

inch at depths of 6 and 8 feet below water surface, respectively, as measured by

geophones 6 and 16 feet inland from wall, Brandon Road study, Des Plaines River,

near Joliet, Illinois .....................................................................................................................29

32. Graph showing transverse, longitudinal, and vertical wall velocities of pressure

waves from firing of two 80-cubic-inch water guns at 6 and 8 feet below water

surface, respectively, as measured by three three-component geophones placed

6 feet from edge of channel at various offsets from the center line of experiment,

Brandon Road study, Des Plaines River, near Joliet, Illinois...............................................29

Figures—Continued
vi

33. Graph showing transverse, longitudinal, and vertical wall velocities of pressure

waves from firing of a single 80-cubic-inch water gun and two 80-cubic-inch water

guns at depths of 6 and 8 feet below water surface, respectively, and all fired at

1,000 pounds per square inch, as measured by geophones 6 and 16 feet inland from

wall, Brandon Road study, Des Plaines River, near Joliet, Illinois .....................................30

34. Graphs showing acceleration of pressure wave velocities as water gun input

pressure increases in vertical and horizontal directions, Brandon Road study, 

Des Plaines River, near Joliet, Illinois .....................................................................................31

35. Graphs showing pressure measurements at depths of 4, 14, and 22 feet below

water surface from two 80-cubic-inch water guns, a single 80-cubic-inch water

gun suspended at a depth of 4 feet below water surface, and a single

80-cubic-inch water gun suspended at a depth of 14 feet below water surface, 

and all fired at 2,000 pounds per square inch at distances of 30 to 90 feet from the

testing wall, Chicago Sanitary Ship Channel, near Lemont, Illinois...................................32

36. Map showing pressure measurements at a depth of 6 feet below water surface

from a single 80-cubic-inch water gun fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................33

37. Map showing pressure measurements at a depth of 6 feet below water surface

from two 80-cubic-inch water guns both fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................34

38. Map showing pressure measurements at a depth of 14 feet below water surface

from a single 80-cubic-inch water gun fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................35

39. Map showing pressure measurements at a depth of 14 feet below water surface

from two 80-cubic-inch water guns both fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................36

40. Map showing pressure measurements at a depth of 22 feet below water surface

from a single 80-cubic-inch water gun fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................37

41. Map showing pressure measurements at a depth of 22 feet below water surface

from two 80-cubic-inch water guns both fired at 2,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................38

42. Map showing pressure measurements at a depth of 6 feet below water surface

from a single 80-cubic-inch water gun fired at 1,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................39

43. Map showing pressure measurements at a depth of 6 feet below water surface

from two 80-cubic inch water guns both fired at 1,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................40

44. Map showing pressure measurements at a depth of 14 feet below water surface

from a single 80-cubic-inch water gun fired at 1,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................41

45. Map showing pressure measurements at a depth of 14 feet below water surface

from two 80-cubic-inch water guns fired at 1,000 pounds per square inch, Chicago

Sanitary Ship Channel, near Lemont, Illinois .........................................................................42

46. Map showing pressure measurements at a depth of 22 feet below water surface

from a single 80-cubic-inch water gun fired at 1,000 pounds per square inch,

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................43

Figures—Continued
vii

47. Map showing pressure measurements at a depth of 22 feet below water surface 

from two 80-cubic-inch water guns both fired at 1,000 pounds per square inch, 

Chicago Sanitary Ship Channel, near Lemont, Illinois..........................................................44

48. Graph showing highest velocities from water guns recorded by surface geophones

during the 2011 replicate scenario for water guns placed 30 feet from the canal

wall and fired at an input pressure of 2,000 pounds per square inch, Chicago

Sanitary Ship Channel, near Lemont, Illinois .........................................................................45

49. Graph showing highest vertical velocities from water guns recorded by surface

and downhole geophones during the 2011 replicate scenario for water guns placed

30 feet from the canal wall and fired at an input pressure of 2,000 pounds per

square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois ..................................45

50. Graph showing geophone positions along the canal wall relative to water gun

center line and velocities recorded at each position from a water gun fired about

40 feet from the wall at a depth of 14 feet below water surface, Chicago Sanitary

Ship Channel, near Lemont, Illinois .........................................................................................46

51. Graphs showing maximum velocities recorded for the 2011 replicate scenario and

the double gun grid scenario high pressure trial by the red surface geophone

placed 5 feet from the canal wall and borehole geophones placed 5 and 35 feet

from the canal wall, Chicago Sanitary Ship Channel, near Lemont, Illinois .....................47

52. Graph showing transverse, longitudinal, and vertical velocities of a single water

gun with input pressures of 1,000 and 2,000 pounds per square inch placed 40 feet

from the canal wall, as measured by the red surface geophone placed 15 feet

downstream of the center line and 5 feet from the canal wall, Chicago Sanitary

Ship Channel, near Lemont, Illinois .........................................................................................48

53. Graph showing transverse, longitudinal, and vertical velocities of a single water

gun with input pressure of 1,000 pounds per square inch placed 40 feet from the

canal wall and 14 feet below water surface, as measured by surface geophones

placed 5 and 15 feet from the canal wall and offset either 5 feet upstream or 

5 feet downstream of the water gun, Chicago Sanitary Ship Channel, near 

Lemont, Illinois ............................................................................................................................48

54. Graphs showing changes in acceleration of pressure wave velocities as water gun

distance to the canal wall decreases for the vertical and horizontal components of

a double gun firing 40 and 120 feet from the canal wall, Chicago Sanitary Ship

Channel, near Lemont, Illinois ..................................................................................................49

55. Graphs showing changes in water pressure as three-dimensional distance from

water guns(s) to hydrophone increases when firing one 80-cubic-inch water gun at

1,000 pounds per square inch at Brandon Road study area, Des Plaines River, near

Joliet, Illinois; and Lemont study area, Chicago Sanitary Ship Channel, near

Lemont, Illinois ............................................................................................................................51

56. Graphs showing changes in water pressure as three-dimensional distance from

water guns to hydrophone increases when firing two 80-cubic-inch water guns at

1,000 pounds per square inch at Brandon Road study area, Des Plaines River, near

Joliet, Illinois; and Lemont study area, Chicago Sanitary Ship Channel, near

Lemont, Illinois ............................................................................................................................52

57. Graphs showing changes in water pressure as three-dimensional distance from

water guns to hydrophone increases when firing two 80-cubic-inch water guns at

2,000 pounds per square inch at Brandon Road study area, Des Plaines River, near

Joliet, Illinois; and Lemont study area, Chicago Sanitary Ship Channel, near

Lemont, Illinois ............................................................................................................................53

Figures—Continued
viii

Conversion Factors

Inch/Pound to International System of Units

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Volume

cubic inch (in3

) 16.39 cubic centimeter (cm3) 

Sensitivity

volts per foot per square seconds 

[V/(ft/s2

)]

0.3048 volts per meter square seconds 

[V/(m/s2

)]

Velocity

inch per second (in/s) 0.0254 meter per second (m/s)

Acceleration

foot per square second (ft/s2

) 3.280 meter per square second (m/s2)

Pressure

pound per square inch (lb/in2

) 6.895 kilopascal (kPa) 

cubic foot per minute (ft3

/min) 0.0348 cubic meter per minute (m3/min)

International System of Units to Inch/Pound

Multiply By To obtain

Volume

cubic centimeter (cm3

) 0.06102 cubic inch (in3) 

Sensitivity

volts per meter per second 

[V/(m/s)]

3.280 volts per foot per second

[V/(ft/s)]

Datums

Horizontal coordinate information is referenced to the World Geodetic System 1983 (WGS 83).

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

(NAVD 88).
ix

Abbreviations

bgs below ground surface

bws below water surface

CSSC Chicago Sanitary and Ship Canal

CAWS Chicago Area Waterway System

DR Direct Reflect

GNSS Global Navigation Satellite Systems

Hz hertz

kHz kilohertz

NE/SW northeast-southwest

NW/SE northwest-southeast

PVC polyvinyl chloride

3C three-component

USACE U.S. Army Corps of Engineers

VRS Virtual Reference Station

Water Pressure and Ground Vibrations Induced by 

Water Guns near Brandon Road Lock and Dam and 

Lemont, Illinois

By Ryan F. Adams, Carolyn M. Koebel, and William S. Morrow

Abstract

Multiple geophysical sensors were used to characterize 

the underwater pressure field and ground vibrations of a 

seismic water gun and its suitability to deter the movement 

of Asian carps (particularly the silver [Hypophthalmichthys 

molitrix] and bighead [Hypophthalmichthys nobilis] carps) 

while ensuring the integrity of surrounding structures. The 

sensors used to collect this information were blast-rated 

hydrophones, surface- and borehole-mounted geophones, and 

fixed accelerometers.

Results from two separate studies are discussed in this 

report. The Brandon Road study took place in May 2014, 

in the Des Plaines River, in a concrete-walled channel 

downstream of the Brandon Road Lock and Dam near Joliet, 

Illinois. The Lemont study took place in June 2014, in a 

segment of the dolomite setblock-lined Chicago Sanitary and 

Ship Canal near Lemont, Illinois.

Two criteria were evaluated to assess the potential 

deterrence to carp migration, and to minimize the expected 

effect on nearby structures from discharge of the seismic 

water gun. The first criterion was a 5-pound-per-square-inch 

(lb/in2) limit for dynamic underwater pressure variations. The 

second criterion was a maximum velocity and acceleration 

disturbance of 0.75 inch per second (in/s) for sensitive 

machinery (such as the lock gates and pumps) and 2.0 in/s 

adjacent to canal walls, respectively. The criteria were based 

on previous studies of fish responses to dynamic pressure 

variations, and effects of vibrations on the structural integrity 

of concrete walls.

The Brandon Road study evaluated the magnitude 

and extent of the pressure field created by two water gun 

configurations in the concrete-walled channel downstream 

of the lock where channel depths ranged from 11 to 14 feet 

(ft). Data from a single 80-cubic-inch (in3) water gun 

set at 6 ft below water surface (bws) produced a roughly 

cylindrical 5-lb/in2 pressure field 20 ft in radius, oriented 

vertically, with the radius decreasing to less than 15 ft at 

the water surface. A combination of two 80-in3 water guns 

set at 6 and 8 ft, respectively, produced a similarly shaped 

5 lb/in2 pressure field 30 ft in radius. Neither of the water 

gun configurations exceeded the given threshold of 5 lb/in2

above the static pressure along the walls of the canal at the 

700 lb/in2 water gun input pressure. Velocity and acceleration 

data were collected simultaneously with the underwater 

pressure data to understand the response of adjacent canal 

walls to the water gun firings. Maximum velocity and 

acceleration were 0.239 in/s and 0.0188 feet per second 

squared (ft/s2), respectively.

The Lemont study replicated and expanded upon work 

done in 2011. The pressure field created by the water gun was 

evaluated in a deeper environment (about 25 ft of water depth) 

than that of the Brandon Road study. To replicate the 2011 

study, data were collected with the same water gun placements 

and input pressure, but static underwater pressure monitoring 

was added. Two 80-in3 water guns were suspended below 

a platform at depths of 4 and 14 ft bws. Pressure was lower 

when the gun suspended at 4 ft bws was fired as compared 

to firing the single gun suspended at 14 ft bws. Firing both 

guns simultaneously produced similar pressures to the single 

gun suspended at 14 ft bws. Data were collected to assess the 

pressure field produced by two 80-in3

 water guns separated 

by 80 ft and suspended at a depth of 14 ft bws. The spatial 

extent of the 5-lb/in2 threshold varied substantially with gun 

input air pressure. Firing the water gun with an air pressure 

of 2,000 lb/in2 generated a pressure field greater than the 

threshold at all but one location in the measured region. 

Additionally, the water gun with an air pressure of 1,000 lb/in2

did not reach the threshold anywhere in the measured region. 

Maximum velocity and acceleration were 0.304 in/s and 

0.015 ft/s2, respectively.
2 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Introduction

The construction of the Chicago Sanitary and Ship 

Canal (CSSC) and the encompassing Chicago Area 

Waterway System (CAWS) in the early 20th century created 

a 28-mi waterway between Lake Michigan and the Illinois 

River, artificially connecting the Great Lakes Basin with 

the Mississippi River Basin. This waterway enabled the 

movement of aquatic species between the Illinois River 

and Lake Michigan. The Asian carps, particularly the silver 

(Hypophthalmichthys molitrix) and bighead (H. nobilis) carps, 

are invasive aquatic species, with a large sustaining population 

in the Illinois River (Adams and Morrow, 2015). Currently 

(2016), the electric dispersal barriers near Romeoville, Illinois 

(U.S. Army Corps of Engineers, 2011) deter fish migration 

between the Mississippi River Basin and the Great Lakes 

Basin. Research is underway on additional measures to deter 

the movement of these fish.

The U.S. Geological Survey (USGS), in cooperation 

with the U.S. Environmental Protection Agency, Great Lakes 

Restoration Initiative, is evaluating the underwater pressure 

field and ground vibrations produced from the firing of a 

seismic water gun (fig. 1) and its potential effectiveness of 

producing a pressure barrier to prevent or direct the movement 

of the Asian carps while ensuring the integrity of surrounding 

structures (Turnpenny and Nedwell, 1994; Keevin and 

Hempen, 1997; Wardle and others, 2001; Lokkeborg and 

others, 2012; Gross and others, 2013). The water gun uses 

large amounts of high-pressure air to rapidly eject a volume of 

water from the water gun chamber. The ejection of the water 

creates a vacuum that is rapidly filled by the collapse of water 

back into the empty space, creating an implosion and resulting 

pressure wave. 

Purpose and Scope

The purpose of this report is to define the magnitude and 

extent of the pressure field created by 80-in3 water guns fired 

at two test areas at various depths and gun pressures in the 

Des Plaines River and the CSSC. The seismic acceleration 

and velocity response of the walls at the two areas from water 

gun firing were recorded to determine safe water gun input 

pressure and distance from surrounding structures. The two 

test areas are the channel downstream of the Brandon Road 

Lock and Dam at Joliet, Illinois, and an open channel area 

along the CSSC upstream of Lemont, Illinois. At the Lemont 

test area, data also were collected to augment previous 

seismic data collected in September of 2011 (Morrow and 

others, 2015).

The data collected and analyzed for this report are 

available in comma-separated values format in Adams and 

others (2017).

Brandon Road Test Area Description

The Brandon Road Lock and Dam is located near Joliet, 

Illinois. The lock, which is 600 feet (ft) long and 110 ft wide, 

helps boats navigate a 34-ft drop in water surface elevation 

between the Lake Michigan and Illinois River sides of the 

structure (U.S. Army Corps of Engineers, 2015). The defined, 

concrete-walled channel downstream of the lock is 110 ft 

wide and about 285 ft long, with a wider channel farther 

downstream about 250 ft wide and 1,700 ft long (fig. 2). The 

mid-channel depth is about 14 ft bws, with depths varying 

across the channel from 11 to 14 ft bws. The surrounding 

bedrock is dolomite.

The water gun, or guns, were set approximately 

250 ft downstream of the downstream lock gates and 40 ft 

upstream of the end of the south canal wall (also referred to 

as the testing wall), and were secured mid-channel (fig. 2). 

The testing was done in a two-wall section of the channel 

because the pressure wave from the gun is influenced by the 

confined space.

Lemont Test Area Description

The Lemont test area in the CSSC was selected based on 

the topographical and geological similarity of the site to the 

electric dispersal barrier site near Romeoville, Illinois. The 

open CSSC channel also represents typical channel geometry 

along the CSSC. Dolomite or dolomite setblock composes 

the canal walls. The width of the canal at the testing point 

was about 167 ft, with a canal depth of about 25 ft extending 

approximately to the canal walls. The location is about 5 mi 

upstream of the electric dispersal barrier at the end of a 

roadway and cul-de-sac off the Illinois and Michigan Canal 

bike path on Cook and DuPage County Forest Preserve 

land (fig. 3).

Port

hole

Solenoid

valve

High

pressure

air

Firing

chamber

Shuttle

Charged Fired Implosion

Figure 1. Water gun firing schematic (diagram redrafted from 

Layhee and others, 2013).
Introduction 3

mad16-1648_fig02

Geophone/Accelerometer

positions

Water gun air

compressor

location

Hydrophone and

water gun testing

Des Plaines River

Brandon Road

Lock and Dam South Brandon Road

0 50 100 150 200 FEET 250

0 10 20 30 40 METERS 50

88°06'20" 88°06'18" 88°06'16" 88°06'14" 88°06'12"

41°

30'

12"

41°

30'

10"

41°

30'

08"

41°

30'

06"

41°

30'

04"

Base imagery from DigitalGlobe 0.3 meter resolution imagery,

March 13, 2012. Accessed June 2015 through Esri World

Imagery Web service. World Geodetic System 1983

ILLINOIS

WISCONSIN

INDIANA

IOWA

MISSOURI

River

Mississippi

Illinois River

Map

area

Romeoville

Lake Michigan

Joliet

Chicago Area

Waterway 

System (CAWS)

Figure 2. Location of study area and major sensor groups (hydrophones, geophones, and accelerometers), Des Plaines River, 

near Joliet, Illinois.
4 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig03

Borehole

Compressor

Borehole

Borehole

Chicago Sanitary and Ship Canal

Flow

Water gun

testing area

0 20 40 60 80 FEET 100

0 10 20 30 METERS

Base image from USDA National Agriculture

Imagery Program (NAIP), Illinois, April 2013.

World Geodetic System 1983

N

ILLINOIS

Map area

Romeoville

Figure 3. Location of Lemont water gun test and data collection areas, Chicago Sanitary 

Ship Channel, near Lemont, Illinois.

Methods

Seismic data were acquired during May 19–22, 2014, at 

the Brandon Road test area, and during June 2–5, 2014, at the 

Lemont test area.

Underwater pressure data were collected using blast 

hydrophones and underwater blast sensors. Pressure was 

monitored to determine areal coverage as well as depth, and 

to determine if the 5-lb/in2

 threshold, or greater pressure, 

was created at wall structures. Fish behavior data collected 

during pond experiments at the U.S. Geological Survey Upper 

Midwest Environmental Sciences Center indicated that a 

pressure near 4 lb/in2 was sufficient to affect the movement of 

Asian carps (Romine and others, 2015). Additionally, 5 lb/in2

greater than the static water pressure was given as the pressure 

limit in the use of water guns near sensitive structures (Fred 

Joers, U.S. Army Corp of Engineers, oral commun., 2013). 

In recognition of both these values, 5 lb/in2

 was used as a 

benchmark for the evaluation of water gun pressure fields. 

These pressure data were used to create pressure maps at 

various depths for each scenario tested.

Land data consisting of velocity and acceleration 

measurements were collected using geophones and 

accelerometers for transverse, longitudinal, and vertical wave 

propagation. Velocities and accelerations were collected at and 

away from the canal wall relative to varying distances of the 

water gun or guns from the wall. Velocity data were monitored 

for exceedances of the U.S. Bureau of Mines standard of 
Methods 5

2 inches per second (in/s) for adjacent structures (Siskind and 

others, 1980)—in this case, the adjacent canal walls—and 

0.75 in/s (velocity threshold for sensitive machinery areas) as 

requested by the U.S. Army Corps of Engineers (Fred Joers, 

U.S. Army Corps of Engineers, written commun., 2013). For 

this report, the lower velocity level of 0.75 in/s is referenced 

for comparisons.

Equipment

One or two 80-in3 (1,310-cubic-centimeter [cm3]) water 

guns were deployed during these studies. The water guns 

were suspended from anchored 6 × 6 ft floating platforms. 

The firing of each water gun was controlled by a HotShot®

controller (Real Time Systems, Fredericksburg, Texas) 

tethered to a laptop computer. High-pressure air was supplied 

to each gun by a high-pressure, high-volume air compressor 

(rated at 5,000 lb/in2 and 81 standard cubic feet per minute 

[ft3/min]).

Hydrophones are piezoelectric sensors used to determine 

the increase in pressure from the water guns. The effect of 

the blast front moving through the water on a quartz crystal 

in the blast hydrophone produces an electrical voltage in 

proportion to the pressure increase. The blast hydrophone 

records only the change in pressure as a result of the water 

gun firing, not the static pressure. These hydrophone sensors 

have a sensitivity of 0.0237 lb/in2. They were sampled at a 

rate of 8,000–32,000 hertz (Hz) (8–32 kilohertz [kHz]) by 

a seismograph. These sensors have a maximum pressure 

threshold of 47 lb/in2. The water guns used in these studies 

generate this pressure threshold out to a maximum distance of 

about 15 horizontal feet from the water gun. To avoid damage 

to the sensors, the sensors always were placed at least 15 ft 

away from the water guns; the area inside this 30-ft-diameter 

circle is referred to as the hydrophone exclusion zone in 

figures and text that follow.

Geophones are mechanical sensors that record the 

magnitude of ground motion using calibrated weights and 

springs. The metal weight moving within a coil of wire 

produces a voltage equivalent to the motion of the geophone. 

This voltage is transmitted through wires to the seismograph.

Three-component (3C) surface geophones (R.T. Clark, 

Oklahoma City, Oklahoma)—with a frequency of 10 Hz, coil 

resistance of 395 ohms, and sensitivity of 27.5 volts per meter 

per second [V/(m/s)]—were used throughout the survey and 

were connected to a seismograph. The seismograph sampled 

these geophones at a rate of 8,000 samples per second (sps) 

for a period of 8 seconds (s). Additional 3C surface geophones 

manufactured by Instantel® (Ogdensburg, New York) were 

used to supplement the R.T. Clark geophones. The Instantel®

geophones were calibrated by the International Society 

of Explosive Engineers 1 month prior to the start of field 

work and were used as quality assurance for the R.T. Clark 

geophones. These geophones have a frequency of 2 Hz and 

a resolution of 0.00031 in/s. They were sampled at a rate of 

16 kHz by a seismograph.

Average maximum velocities are compared in figure 4, 

with 1 standard deviation error, for the near and far Instantel 

(dark and light gray, respectively) and the near and far 

R.T. Clark (red and blue, respectively) geophones for a 

2,000 lb/in2 shot located 50 ft from the canal wall at Brandon 

Road. Velocities for the R.T. Clark and calibrated Instantel®

surface geophones at the same location generally were within 

0.02 in/s of each other, or about 3 percent of the 0.75 in/s limit 

for sensitive structures. At a maximum, the difference between 

the two readings was 0.04 in/s and the average standard 

deviation was about 0.01 in/s. Because these geophones 

pairs produced similar results and the Instantel geophones 

have a flat response over the frequencies of 2–250 Hz, a flat 

conversion was selected to convert millivolts (mV) to inches 

per second (in/s) for the R.T. Clark geophones. Using the 

geophone sensitivity of 27.5 [V/(m/s)], 1 mV is equivalent to 

0.00143 in/s (It is noteworthy that the value of 0.00143 in/s 

here differs from 0.00031 in/s for 27.5 [V/(m/s)] in the 

previous paragraph). 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Transverse Longitudinal Vertical

Velocity, in inches per second

Geophone component

Near dark gray geophone

Near red geophone

Far light gray geophone

Far blue geophone

EXPLANATION Figure 4. Velocities of near 

(6 feet from wall, dark gray) 

and far (16 feet from wall, light 

gray) Instantel® and near (6 feet 

from wall, red) and far (16 feet 

from wall, blue) R.T. Clark 

surface geophone pairs from a 

2,000-pound-per-square-inch 

shot located 50 feet from canal 

wall. Velocities are plotted with 

1 standard deviation error.
6 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Downhole 3C land geophones manufactured by R.T. 

Clark with a frequency of 10 Hz, coil resistance of 395 ohms, 

and a sensitivity of 27.5 [V/(m/s)] were used in the three 

boreholes and the 3-in. polyvinyl chloride (PVC) pipe affixed 

to the side of the canal wall at Lemont. The geophones were 

held in place at the desired elevation by attached steel springs 

that were manually released, causing the springs to expand 

and seat firmly against the borehole. The seismograph sampled 

these geophones at a rate of 8,000 sps for a period of 8 s.

Acceleration was recorded using two, one-component 

accelerometers. These sensors were sampled at 8,000–

32,000 sps by a data-acquisition system. These sensors 

have a sensitivity of 0.309 volts per foot per square seconds 

[V/(ft/s2)].

Brandon Road Study

The Brandon Road study consisted of four water-gun 

scenarios. The scenarios had similar goals—to determine the 

maximum safe gun input pressure and distance from concrete 

canal walls for a single water gun or a pair of water guns such 

that the ground velocity does not exceed 0.75 in/s and the 

pressure on the canal walls does not exceed 5 lb/in2. These 

scenarios were as follows:

1. Varying gun distance. One 80-in3 water gun was 

placed at multiple distances from the canal wall and 

fired at increasing pressures to determine the safe 

operating conditions.

2. Single gun radial. One 80-in3 water gun was placed 

in the center of the channel (55 ft from the right bank 

wall; right or left is from the perspective of an observer 

looking downstream) and hydrophone data were 

recorded radially to understand the extent and azimuthal 

variability of the pressure field.

3. Static boom high pressure tests. A single 80-in3 and 

two 80-in3 water guns were placed in the center of the 

channel (55 ft from the right bank wall) and fired at 

high input pressures (1,000–2,000 lb/in2

) to evaluate the 

effects on pressure and velocity.

4. Double gun radial. Two 80-in3 water guns were 

suspended at two different depths, fired simultaneously, 

and hydrophone data were measured radially to evaluate 

the interactions of multiple pressure fields.

The locations of the water guns, hydrophones, and 

geophones were determined using a laser transit. A temporary 

benchmark and reference points were established using a 

Trimble® R8 Global Navigation Satellite Systems (GNSS) 

receiver, and positions were corrected in real-time using the 

Trimble Virtual Reference Station (VRS) Now® service. The 

temporary bench mark and reference points were referenced to 

a horizontal datum of World Geodetic System 1983 (WGS 83) 

and vertical datum of North American Vertical Datum of 1988 

(NAVD 88). The Trimble® 5600 Direct Reflect (DR) 20 0+ 

Total Station was positioned at the established benchmark 

and the survey was corrected for position, rotation, and scale 

by shooting a prism at each reference point measuring its 

distance. With the Total Station survey setup complete, the 

direct reflex method (David Fazio, U.S. Geological Survey, 

written commun., 2017) was used to determine the positions 

of the water guns, hydrophones, and geophones. Those 

positions were recorded in the Trimble Survey Controller. 

Georeferencing targets located on the boom and a central point 

on the water gun platform were surveyed using direct reflex to 

determine the position of the hydrophone boom.

Hydrophones were moved to various positions around 

the water guns to define the extent of the resulting pressure 

field. For most setups, the water guns were secured in a 

fixed position and depth and fired at a constant pressure. The 

hydrophones were suspended from a 30-ft-long rectangular 

PVC boom (figs. 5–8) that pivoted from the water gun 

location. Four groups of six sensors each (24 total) were 

suspended beneath this boom at depths of 0, 2, 4, 6, 8, and 

9 ft, with an even horizontal spacing of 10 ft. The boom was 

moved sequentially in the water surrounding the water gun 

to collect pressure data. Five water gun shots were taken at 

each boom position. For each shot, the maximum value was 

recorded (data are logged every 0.0000625 s for 3 s following 

firing). The arithmetic mean of the five maximum values 

recorded at each hydrophone position and the processed 

location data were used to create the pressure map figures.

Seismic velocity data were collected using geophones 

and accelerometers. The locations of the water gun or guns 

remained fixed for most scenarios. Multiple geophone 

configurations were used for the water-gun scenarios to obtain 

detailed coverage of the velocity response of the area behind 

the canal wall. Accelerometer locations were fixed.

Two single-component accelerometers were attached 

to an aluminum block mounted on top of the concrete wall 

(figs. 5–8). This block was placed about 3 in. from the edge 

of the wall and directly on the center line, the line created 

between the water gun and the hydrophone boom when 

the boom was directly perpendicular to the testing wall. 

One accelerometer was mounted vertically on top of the 

rectangular block and the other was mounted horizontally on 

the side facing the river and water gun. For the vertical unit, 

a positive deflection indicated upward movement toward the 

sky and a negative deflection indicated downward movement 

toward the ground. For the horizontal unit, a positive 

deflection indicated movement of the wall outwards toward 

the river and a negative deflection indicated movement inward 

toward the geophone array. The accelerometers remained fixed 

for the duration of the experiment.

Six R.T. Clark and two Instantel® 3C geophones were 

used to record seismic velocities. The exact positions of 

the geophones were determined by using laser transit, 

and positions were referenced to the edge of the wall and 

the center line. Each of the otherwise identical R.T. Clark 

geophones was assigned a color to identify it for discussion in 

this report, and the Instantel® geophones were fixed in place 

and referenced as “Near” and “Far” from the edge of the 

concrete wall (figs. 5–8).
Methods 7

mad16-1648_fig05

Base image from Google Maps Street View, October 2013, 

S Brandon Rd, Joliet, Illinois. View accessed January 2016.

Brandon Road

R.T. Clark

geophones

Instantel®

geophones

Water gun movement

Des Plaines River

Flow

Hydrophone boom

Accelerometer

N

Geophones

EXPLANATION

White

Green

Pink

Orange

Red

Blue

Gray

Figure 5. Water gun, geophone, and accelerometer positions for varying gun distance scenario, Brandon Road study, 

Des Plaines River, near Joliet, Illinois.

Base image from Google Maps Street View, October 2013, 

S Brandon Rd, Joliet, Illinois. View accessed January 2016.

R.T. Clark

geophones

Instantel®

geophones

Hydrophone

boom

Water gun

Accelerometer

Hydrophone

boom movement

Des Plaines River

Flow

N

Brandon Road

Geophones

EXPLANATION

White

Green

Pink

Orange

Red

Blue

Gray

Figure 6. Water gun, geophone, and accelerometer positions for single gun radial scenario, Brandon Road study, Des 

Plaines River, near Joliet, Illinois.
8 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig07

Accelerometer

Flow

Base image from Google Maps Street View, October 2013, 

S Brandon Rd, Joliet, Illinois. View accessed January 2016.

R.T. Clark

geophones

Instantel®

geophones

Hydrophone boom

Water guns

Des Plaines River

N

Brandon Road

Geophones

EXPLANATION

White

Green

Pink

Orange

Red

Blue

Gray

Figure 7. Water gun, geophone, and accelerometer positions for static boom high pressure scenario, Brandon Road 

study, Des Plaines River, near Joliet, Illinois.

Base image from Google Maps Street View, October 2013, 

S Brandon Rd, Joliet, Illinois. View accessed January 2016.

R.T. Clark

geophones

Instantel®

geophones

Hydrophone

boom

Accelerometer

Hydrophone

boom movement

Des Plaines River

Flow

Water guns

N

Brandon Road

Geophones

EXPLANATION

White

Green

Pink

Orange

Red

Blue

Gray

Figure 8. Water gun, geophone, and accelerometer positions for double gun radial scenario, Brandon Road study, Des 

Plaines River, near Joliet, Illinois.
Methods 9

Varying Gun Distance Scenario

One 80-in3 water gun was placed in the center of the 

channel (initially 55 ft from the wall) and then was moved 

closer in 5-ft increments (fig. 5). The gun ports were aligned 

approximately northwest-southeast (NW/SE) such that 

they were perpendicular to the walls of the channel and 

positioned at a depth of 6 ft bws. The single water gun was 

fired at increasing input pressures, beginning at 500 lb/in2

(the operational minimum) and proceeding until the 5-lb/in2 

pressure threshold at the wall was reached. The input pressure 

ranged from 750 to 500 lb/in2 based on the distance from the 

wall. Once the 5 lb/in2 pressure limit was reached at a testing 

location, the water gun was moved 5 ft closer to the testing 

wall and testing resumed at the minimum pressure. 

The hydrophone boom was positioned approximately 

NW/SE such that it was perpendicular to the walls of the 

channel and located 17.5 ft from the edge of the water gun 

platform and 8 ft from the edge of the testing wall. For this 

setup, the two hydrophone groups in the center of the boom 

(at 27.5 and 37.5 ft from the gun, respectively) were recording 

data. A separate group of hydrophones were suspended 

directly from the wall using a spacer to achieve a distance 

of 1 ft from the wall. The hydrophone boom remained fixed 

relative to the wall throughout the scenario.

Single Gun Radial Scenario

One 80-in3 water gun was placed in the center of the 

channel (55 ft from the wall). The ports were aligned roughly 

NW/SE such that they were perpendicular to the walls of the 

channel and were positioned at a depth of 6 ft bws. The single 

water gun was fired at 700 lb/in2 based on the results from the 

varying gun distance scenario.

The hydrophone boom initially was positioned with the 

first hydrophone group 15 ft from the edge of the water gun 

platform and roughly aligned NW/SE such that the boom was 

directly perpendicular to the testing wall. From this initial 

position, the hydrophone boom was swung around the water 

gun at about 30-degree increments (fig. 6).

Static Boom High Pressure Scenario

One 80-in3 water gun was placed in the center of the 

channel (55 ft from the wall). The ports were aligned roughly 

NW/SE such that they were perpendicular to the walls of the 

channel and were positioned at a depth of 6 ft. The single 

water gun was fired at increasing pressures beginning at 

500 lb/in2 (the operational minimum) and increasing to as 

much as 2,000 lb/in2 (the operational maximum). Once the 

water gun was pressurized to 1,000 lb/in2, the number of shots 

for each pressure was reduced in accordance with U.S. Army 

Corps of Engineers (USACE) personnel on site monitoring the 

wall pressure and velocity readings. Instead of the standard 

five shots, the number of shots for each pressure greater than 

1,000 lb/in2 ranged from 2 to 4 (fig. 7) to reduce the possibility 

of negative effects on the integrity of the wall.

After the highest pressure was completed with one gun, 

a second water gun was placed next to the original water gun. 

These two, 80-in3 water guns were located in the center of the 

channel (55 ft from the wall). The two water gun platforms 

were fastened together and the water guns were suspended 

below them with a horizontal offset of about 6 ft from 

one gun to another. The ports of the first gun were aligned 

approximately NW/SE, perpendicular to the walls, at a depth 

of 6 ft bws; the second gun was placed orthogonally to the first 

but with the gun ports aligned northeast-southwest (NE/SW), 

parallel to the walls, at a depth of 8 ft bws. 

The two guns were fired in a staggered fashion, with 

the gun 8 ft bws being fired first and then both guns being 

fired together. Data were collected for both the single and 

double water gun shots, with water gun pressures starting at 

500 lb/in2 (the operational minimum) and increasing to as 

much as 2,000 lb/in2 (the operational maximum). As pressures 

increased to more than 1,000 lb/in2, the number of shots at a 

given pressure was decreased to between 2 and 4.

Double Gun Radial Scenario

This scenario was set up identically to the static boom 

high pressure scenario. Two, 80-in3 water guns were placed in 

the center of the channel with a horizontal offset of about 6 ft 

from one gun to another. Gun ports aligned roughly NW/SE 

perpendicular to the walls at a depth of 6 ft bws; the other gun 

was placed orthogonally with the gun ports aligned NE/SW 

parallel to the walls at a depth of 8 ft bws.

The water gun or guns were fired at 1,000 lb/in2 in a 

staggered fashion, with 5 shots collected on the 8-ft-deep gun 

alone and then 5 shots collected on both guns fired together. 

Once the data were collected, the boom was rotated 45 degrees 

and data were collected again. Data coverage of this area was 

obtained, consisting of the semicircle located 180 degrees 

from of the northwestern side of the channel facing the testing 

wall (fig. 8).

Lemont Study

The CSSC upstream of Lemont is about 160 ft wide and 

25 ft deep, making this test area greater in depth and width 

than the Brandon Road test area. Additionally, the three 

previously (2011) installed boreholes at Lemont allowed 

monitoring at depth of the land mass affected by the seismic 

energy created by the water guns, as well as its surface.

Two scenarios were tested in the data collection at Lemont:

1. 2011 replicate. Two 80-in3 water guns were set up in 

the CSSC to recreate the testing done on the same site 

in 2011 (Morrow and others, 2015), as well as to collect 

additional data at different water gun depths.
10 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

2. Double gun grid. Two 80-in3 water guns were set up 

spaced apart across the channel and at equal depths 

in the CSSC to evaluate the extent and magnitude of 

the pressure field created. This scenario was repeated 

twice—once at 2,000 lb/in2 (high pressure), and once at 

1,000 lb/in2 (low pressure).

Because of the approximate 25-ft depth of the CSSC, the 

hydrophones were deployed differently during Lemont testing 

than they were during Brandon Road testing. Hydrophones 

were suspended on chains hanging from a large buoy at the 

water surface. Two strings of hydrophones were used and kept 

at fixed 10-ft spacing.

The locations of the water guns, hydrophones, and 

geophones were determined using a laser transit. A temporary 

benchmark and reference points were established using a 

Trimble® R8 GNSS receiver, and positions were corrected 

in real-time using the Trimble VRS Now® service. The 

temporary bench mark and reference points were referenced 

to a horizontal datum of WGS 83 and vertical datum of 

NAVD 88. The Trimble® 5600 DR 200+ Total Station was 

positioned at the established benchmark and the survey 

was corrected for position, rotation, and scale by shooting a 

prism at each reference point measuring its distance. With 

the Total Station survey setup complete, the direct reflex 

method was used to determine the positions of the water 

guns, hydrophones, and geophones that were recorded in the 

Trimble Survey Controller. Georeferencing targets located 

on the boom and a central point on the water gun platform 

were surveyed using direct reflex to determine the position of 

the hydrophone boom. At each water gun location, the water 

guns were secured at a fixed position and depth and fired at 

a constant pressure. When referencing equipment positions, 

the “center line” describes an imaginary line running between 

the water guns to the canal wall. Sensors were suspended 

in the water column at a fixed distance and depth and then 

moved sequentially in the water surrounding the water gun 

to record data. Five water gun shots were fired at each point 

location. For each shot, the maximum value was recorded 

(data are logged at 16,000 sps for 3 s following firing). The 

arithmetic mean of the five maximum values recorded at each 

hydrophone position and the processed location data were 

used to create the pressure map figures.

As with the Brandon Road study, seismic velocity data 

were collected using geophones and accelerometers. Water 

guns remained fixed for the second scenario, allowing for the 

geophones to be moved to various positions for more detailed 

coverage of the velocity response of the area behind the canal 

wall. Specific sensor positions are shown in the scenario 

descriptions (figs. 9 and 10). As many as six downhole 3C 

geophones and five R.T. Clark 3C surface geophones were 

used in the monitoring (figs. 9 and 10). The transverse 

component was oriented parallel with the canal (east-west) 

and the longitudinal component was oriented perpendicular 

(north-south) to the canal. The vertical component was 

perpendicular relative to ground surface.

Downhole geophones were placed inside one of three 

boreholes located on the site. These boreholes were drilled 

during the 2011 work (Morrow and others, 2015). Each 

borehole was a 3- or 4-in.-diameter hole drilled into the 

dolomite setblock used to build the canal walls. Each borehole 

was lined with steel casing until solid bedrock was reached, 

after which an open borehole continued until the end of the 

borehole. The boreholes initially were drilled to a depth of 

30–40 ft bws, allowing placement of the downhole geophones 

at about the same elevation as mid-depth of the CSSC channel. 

The three boreholes were previously drilled 5, 35, and 100 ft 

from the edge of the canal.

Accelerometers were placed on a mounting block and 

affixed to the vertical face of the right bank wall. They 

retained their alignment from the Brandon Road study with the 

vertical component unit mounted on top of the block and the 

longitudinal component unit mounted facing the canal.

All sensor positions were geolocated using a laser transit. 

Each configuration listed its distance from the edge of the 

wall, distance from the center line, and depth.

2011 Replicate Scenario

Two 80-in3 water guns were placed 90 ft from the north 

wall of the CSSC (all geophones were placed generally north 

of this wall area within 100 ft [fig. 9]). The two water gun 

platforms were fastened together and the water guns were 

suspended below them with a horizontal offset of about 6 ft 

from one gun to another. The east gun was suspended from the 

upstream platform, and the west gun was suspended from the 

downstream platform (fig. 9). Both guns were suspended such 

that the guns were parallel with the flow of the CSSC and the 

gun ports were perpendicular to the walls of the CSSC. One 

gun port was at a depth of 4 ft bws, and the other gun ports 

were at depths of 14 ft bws. Beginning at 90 ft from the north 

canal wall, with an operational pressure of 2,000 lb/in2 (the 

operational maximum), 15 shots were taken—firing first the 

14-ft gun, then the 4-ft gun, and finally both guns together. 

Once the data were collected, the guns were moved closer to 

the north wall in 10-ft increments, and the cycle was repeated 

until a distance of 30 ft from the wall was reached (Morrow 

and others, 2015).

Two downhole geophones were placed in each 

borehole—one geophone 5 ft below ground surface (bgs) and 

one geophone 20–25 ft bgs (roughly to the same elevation as 

the 14-ft gun). A surface geophone was placed next to both the 

5- and 35-ft boreholes (fig. 9). Each geophone was assigned an 

identifying color for reference.

The two hydrophone strings were placed along a line 

directly between the water guns and the north wall. The 

hydrophone strings were placed 5 ft and 15 ft from the wall, 

respectively (fig. 9), and remained fixed for the duration of 

the scenario. The 5-ft buoy supported 12 hydrophones from 

0 to 22 ft bws at 2-ft intervals. The 15-ft buoy supported 

6 hydrophones from 12 to 22 ft bws at 2-ft intervals.
Methods 11

mad16-1648_fig09

Platform

Borehole

Compressor

Borehole

Borehole

Chicago Sanitary and Ship Canal

Flow

Water gun

testing area

0 20 40 60 80 FEET 100

0 10 20 30 METERS

Base image from USDA National Agriculture

Imagery Program (NAIP), Illinois, April 2013.

World Geodetic System 1983

N

Geophones

EXPLANATION

Red

Blue

A

A A ́

A ́

NOT TO SCALE

100’

35’

35’

39.4’

29.5’

25’ 25’ 20’

5’ 5’

5’

5’

25’ 5’ 10’ 22’

Water gun

Canal wallCanal wall

Accelerometer

Platform

set from 30 to 90 feet

from north canal wall

Ground surface

Water surface

12’ 14’

4’

A

B

Borehole

Three-component

downhole geophone

Threecomponent

downhole

geophone

Three-component geophone

Borehole

Borehole

Buoy

12 hydrophones,

from 0 to 22 feet deep,

2-foot interval

6 hydrophones,

from 12 to 22 feet deep,

2-foot interval

Three-component geophone

15 feet

Hydrophone setup

shown above

Figure 9. Cross-sectional schematic diagram (A) and plan view (B) of 2011 replicate 

scenario, Chicago Sanitary Ship Channel, near Lemont, Illinois.
12 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig10

Geophones

EXPLANATION

White

Green

Pink

Red

Blue

Base image from USDA National Agriculture

Imagery Program (NAIP), Illinois, April 2013.

World Geodetic System 1983

N

Base image from USDA National Agriculture

Imagery Program (NAIP), Illinois, April 2013.

World Geodetic System 1983

N

0 20 40 60 80 FEET 100

0 10 20 30 METERS

0 20 40 60 80 FEET 100

0 10 20 30 METERS

Geophones

Chicago Sanitary and Ship Canal

Flow

Platform

Platform

Hydrophone setup

shown at left

Platform

Platform

Geophones

Chicago Sanitary and Ship Canal

Flow

A

B

Buoy 10-foot

PVC spacer

Hydrophone

2-foot

spacing

Buoy

Heavy

chain

Hydrophone setup

Hydrophone setup

shown above

Boreholes

Boreholes

Figure 10. Cross-sectional schematic diagram inset (A), and plan views of double 

gun grid high pressure (A) and low pressure (B) scenarios, Chicago Sanitary Ship 

Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 13

Double Gun Grid Scenario

Two 80-in3 water guns were placed along a line 

perpendicular to flow of the CSSC. Each water gun was placed 

43 ft from a canal wall, with a distance of 80 ft between 

the two platforms. Water guns were suspended at a depth 

of 14 ft bws with the gun ports aligned perpendicular to the 

walls. At each position, the water gun or guns were fired 

10 times—5 shots with only the northern gun (closer to the 

geophones) and 5 shots with both guns. This scenario was 

tested twice, once with a gun input pressure of 2,000 lb/in2

(fig. 10A) and, once with a gun input pressure of 1,000 lb/in2 

(fig. 10B).

The surface and the 5-ft borehole geophones collected 

data during this scenario. Surface geophones were laid 

out with 10 ft spacing between them. Geophones initially 

were arranged in a line, as in figure 10A, and then changed 

to a grid on the subsequent day (fig. 10B) to obtain better 

areal coverage.

The hydrophone strings were reconfigured to hold 

9 hydrophones each at 2-ft increments from 6 to 22 ft bws. 

The hydrophones were moved in 10-ft increments along three 

lines parallel (at distances of 20, 30, and 40 ft) to the line 

created by the two water guns. Two to four additional data 

points were collected along the north wall as permitted by the 

pull of the water guns against the current and the suitability of 

anchor points on the north wall.

Results for Water Pressure and 

Ground Vibrations

Brandon Road Water Pressure

During the analysis of hydrophone data collected at 

Brandon Road, certain hydrophones were noted to have 

recorded pressure values an order of magnitude greater than 

the adjacent hydrophones on the same string. After analysis 

of the waveform data collected during each firing of the water 

gun (fig. 11), it was evident that the values were the result 

of an equipment malfunction and were excluded from all 

analyses and pressure maps.

Varying Gun Distance Scenario

This scenario was run as a series of increasing pressure 

tests at decreasing wall distances to determine the operational 

limits of the water guns within the confined space of the 

channel as defined by the USACE.

The variations in pressure, as monitored by the 

hydrophone at 8 ft bws in a group of hydrophones placed 

1 ft from the testing wall, are shown in figure 12. Of the 

6 hydrophones in this group, mounted at depths of 0, 2, 4, 

6, 8, and 9 ft bws, respectively, hydrophones at 6, 8 and 

9 ft bws had some pressures greater than 5 lb/in2, but only the 

8-ft bws hydrophone consistently recorded pressures greater 

than 5 lb/in2.

To keep pressures near the wall lower than the 

5-lb/in2 threshold, gun input pressures should be no greater 

than 700 lb/in2 when the gun is positioned at distances 

of 55 and 50 ft from the testing wall and no greater than 

500 lb/in2 when the gun is at distances of 45 ft from the testing 

wall. With 500 lb/in2 as the minimum input pressure for the 

80-in3 water gun, testing was concluded with the water gun 

45 ft from the testing wall.

Single Gun Radial Scenario

The single gun radial scenario was run to understand 

the extent and azimuthal variability of the pressure field. 

Contoured pressure results at different depths with a gun input 

pressure of 700 lb/in2 and gun ports at a depth of 6 ft bws are 

shown in figures 13–18.

Data showed generally symmetrical pressures that 

gradually increased or decreased over depth with no large 

variations (figs. 13–18). The radial extent of the pressure data 

was maximized at the 6-ft depth of the water gun (fig. 16), 

with the 5-lb/in2 threshold pressure reached across a radius 

of about 20 ft. This radius decreased above and below the 

water gun depth of 6 ft. The extent of the decrease is much 

greater above the gun, with the map at the surface showing no 

areas of threshold pressure (data points were removed from 

the surface map because of an equipment malfunction, as 

described in the “Brandon Road Water Pressure” section). If 

considered vertically, the shape of the 5-lb/in2 pressure field 

contour generally is that of a slightly eccentric circle resulting 

in a somewhat cylindrical pressure field extending from the 

bottom of the canal (fig. 18) to the 2-ft map (fig. 14) before 

sharply diminishing as it approaches the surface (fig. 13). 

Pressure is not measured from 0 to 15 ft from the water gun 

(the exclusion zone boundary) because of the risk of damaging 

the hydrophones.

Static Boom High Pressure Scenario

One water gun was placed 55 ft from the wall, and 

suspended at 6 ft bws, and a second gun was added later at a 

depth of 8 ft bws. The hydrophone boom was placed in line 

with the gun, pointing perpendicular to the testing wall. Data 

collection focused on when water guns were fired at input 

pressures of 1,000–2,000 lb/in2 to understand the response of 

the structure to higher-amplitude pressure waves, compared 

to the previous scenarios. The results of the static boom high 

pressure scenario designed to test limited exposure to high 

pressures and represent a smaller number of shots (2–4) at 

pressures beginning at 1,000 lb/in2 are shown in figures 19–21. 
14 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig11

Time

0.0 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00

Pressure, in pounds per square inch

1.00

2.00

2.00

0.0

-1.00

-2.00

1.00

0.0

-1.00

-2.00

2.00

1.00

0.0

-1.00

-2.00

2.00

1.00

0.0

-1.00

-2.00

2.00

1.00

0.0

-1.00

-2.00

0.40

0.20

0.0

-0.20

-0.40

Hydrophone 1

Hydrophone 2

Hydrophone 3

Hydrophone 4

Hydrophone 5

Hydrophone 6

Figure 11. Effects of equipment malfunction on waveform data from a single hydrophone (pink line, 

Hydrophone 4), Brandon Road study, Des Plaines River, near Joliet, Illinois.
Results for Water Pressure and Ground Vibrations 15

mad16-1648_fig12

0

1

2

3

4

5

6

7

0 10 20 30 40

Hydrophone pressure,

in pounds per square inch

Shot number

EXPLANATION

55 feet 1,000 lb/in2

55 feet 500 lb/in2

55 feet 750 lb/in2

55 feet 700 lb/in2

50 feet 500 lb/in2

50 feet 700 lb/in2

50 feet 750 lb/in2

45 feet 500 lb/in2

45 feet 700 lb/in2

Water gun distance from

 wall and firing pressure

Figure 12. Pressure data from a hydrophone placed 1 foot from testing wall at 

depth of 8 feet below water surface, Brandon Road study, Des Plaines River, near 

Joliet, Illinois. Graph indicates progression of pressure changes as water gun 

distance and input pressure were modified. 

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

Water gun

Hydrophone group position

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Figure 13. Pressure measurements at water surface from a single 80-cubic-inch water gun fired at 700 pounds per 

square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
16 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig14

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

Pressure, in pounds per square inch

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Figure 14. Pressure measurements at a depth of 2 feet below water surface from a single 80-cubic-inch water gun 

fired at 700 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
Results for Water Pressure and Ground Vibrations 17

mad16-1648_fig15

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

Figure 15. Pressure measurements at a depth of 4 feet below water surface from a single 80-cubic-inch water gun 

fired at 700 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
18 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig16

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

Figure 16. Pressure measurements at a depth of 6 feet below water surface from a single 80-cubic-inch water gun 

fired at 700 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
Results for Water Pressure and Ground Vibrations 19

mad16-1648_fig17

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

Pressure, in pounds per square inch

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Figure 17. Pressure measurements at a depth of 8 feet below water surface from a single 80-cubic-inch water gun 

fired at 700 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
20 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig18

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900 1,046,920

1,761,240

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

Pressure, in pounds per square inch

EXPLANATION

9.5

9.0

10.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Figure 18. Pressure measurements at a depth of 9 feet below water surface from a single 80-cubic-inch water gun 

fired at 700 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.

During some of the trials (figs. 20 and 21), data from the 

fourth string of hydrophones (located closest to the water 

gun) were not collected so that the seismograph normally 

used to collect that data could be used to collect additional 

geophone data. Specific details of the setup are noted in the 

figure captions.

In the first part of this scenario, a single 80-in3 water 

gun at a depth of 6 ft bws was fired at 1,000, 1,500, and 

2,000 lb/in2. The images shown in figure 19 represent a 

vertical profile through the canal situated along the center 

line of the setup directly between the water gun and the wall. 

The three profiles showed pressure generally decreasing both 

vertically and horizontally as the horizontal distance from the 

water gun increases. The pressure field distribution shows an 

approximately radial expansion from the point of origin.

The extent of the 5-lb/in2 threshold pressure 

varies based on the water gun input pressure. The extent 

of the 5-lb/in2 threshold pressure difference between 1,000 

(fig. 19A) and 1,500 lb/in2 (fig. 19B) is substantial, with 

nearly 10 additional ft contained with the threshold. Similar 

trends in the pressure data from the varying gun distance 

scenario confirm that changing the gun input pressure from 

1,000 to 1,500 lb/in2 can result in large changes in extent of the 

pressure field. However, differences between 1,500 (fig. 19B) 

and 2,000 lb/in2 (fig. 19C) are much smaller, and primarily 

are variations in intensity rather than extent of the pressure 

field. This result could indicate that each environment has a 

certain tolerance for pressure and that once the optimal gun 

input pressure is exceeded, further increases in the extent of 

the pressure field would be limited. Pressures at the water 

surface are much lower than pressures at depth, even in close 

proximity to the water gun (fig. 19).

The second part of this scenario involved the addition of 

a second 80-in3

 water gun at a depth of 8 ft bws and oriented 

perpendicular to the water gun at 6 ft bws. The 8-ft gun and 

then both guns were fired in a 10-shot sequence. The first five 

firings were with the 8-ft gun, and the last five firings with 

both guns. This sequence was repeated as pressure increased 

from 500 to 1,000 lb/in2 at an interval of 100 lb/in2. A series of 

profiles from each of the water gun configurations is shown in 

figure 20.

The effect of rotating the water gun can be seen in the 

extent of the pressure field. The 5-lb/in2

 contour line moves 

10 ft closer to the water gun in the 8-ft image (fig. 20B) 

relative to the 6-ft image (fig. 20A). The 6-ft profile (fig. 20A) 

projects the target pressure out to a similar distance from the 

wall compared to the two gun profile (fig. 20C).
Results for Water Pressure and Ground Vibrations 21

mad16-1648_fig19 Depth, in feet

-8

-6

-4

-2

0

-8

-6

-4

-2

0

-8

-6

-4

-2

0

NW SE

B

C

A

Distance from testing wall, in feet

5 7 9 11 13 15 17 19 21 23 25

EXPLANATION

Pressure, in pounds

 per square inch

11.5

11.0

12.0

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1..0

0.5

0

Hydrophone

 position

5 pounds per square

 inch contour line

Figure 19. Spatial distribution of pressure for a single 80-cubic-inch water gun placed 55 feet from the testing wall, 6 feet 

below the water surface, and fired at (A) 1,000 , (B) 1,500, and (C) 2,000 pounds per square inch, Brandon Road study, Des 

Plaines River, near Joliet, Illinois.
22 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig20

NW SE

B

C

A

Distance from testing wall, in feet

Depth, in feet

8

6

4

2

0

8

6

4

2

0

8

6

4

2

0

5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35

EXPLANATION

Pressure, in pounds

 per square inch

11.5

11.0

12.0

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Hydrophone

 position

5 pounds per square

 inch contour line

Figure 20. Spatial distribution of pressure for single 80-cubic-inch water guns placed 6 feet below water surface (A) and 8 

feet below water surface oriented orthogonally to the first water gun (B), and for two 80-cubic-inch water guns placed 6 and 8 

feet below water surface, respectively (C), all 55 feet from the testing wall and fired at 1,000 pounds per square inch, Brandon 

Road study, Des Plaines River, near Joliet, Illinois.

In the third part of this scenario, gun positions were 

kept the same and gun input pressure was changed. Two 

water guns were both fired at pressures of 1,300 lb/in2, 

1,500 lb/in2 and 2,000 lb/in2. The differences between firing a 

single water gun at 6 ft and firing both water guns at 6 ft and 

8 ft are shown in figure 21 for a pressure of 2,000 lb/in2. The 

two gun profile (fig. 21B) is constructed from a simultaneous 

firing of both water guns. The radial extent of the target 

pressure is similar between the two profiles. Both profiles 

show a nearly total threshold pressure coverage of the channel, 

with only small areas along the wall remaining at less than the 

5 lb/in2

 threshold pressure. 
Results for Water Pressure and Ground Vibrations 23

mad16-1648_fig21

NW SE

B

A

Distance from testing wall, in feet

Depth, in feet

8

6

4

2

0

8

6

4

2

0

5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35

EXPLANATION

Pressure, in pounds

 per square inch

0

28

30

26

24

22

20

18

16

14

12

10

8

6

4

2

Hydrophone

 position

5 pounds per square

 inch contour line

Figure 21. Spatial distribution of pressure for a single 80-cubic-inch water gun 6 feet below water surface (A), and for two 

80-cubic-inch water guns 6 and 8 feet below water surface (B), all 55 feet from the testing wall and fired at a pressure of 

2,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.

Double Gun Radial Scenario

The double gun radial scenario was designed to 

understand the pressure field surrounding two water guns 

(figs. 22–27) and compare those results to the single gun 

radial scenario.

The addition of a second water gun and an increase in 

input gun pressure from 700 lb/in2 to 1,000 lb/in2 resulted in 

an increase in the radial extent of the 5-lb/in2 pressure field. 

The radius of the threshold pressure increased by a distance 

of greater than 15 ft compared to the single gun radial setup 

(fig. 28), but decreased from the bottom depth of 9 ft (fig. 27) 

up to the 2-ft depth (fig. 23) and then diminished substantially 

at the surface (fig. 22) in a similar manner to the single 

gun maps.

The orthogonally placed gun ports on the deeper 8-ft 

water gun (relative to the 6-ft water gun) seem to reduce the 

horizontal eccentricity of the pressure field (figs. 22–27). 

Although the change in shape was expected, some of the 

eccentricity may be due to a decrease in sampling density. 
24 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig22

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

15

Pressure, in pounds per square inch

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Water gun

Hydrophone group position

EXPLANATION

Figure 22. Pressure measurements at water surface from two 80-cubic-inch water guns fired at 1,000 pounds per 

square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

15

Pressure, in pounds per square inch

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

EXPLANATION

Figure 23. Pressure measurements at a depth of 2 feet below water surface from two 80-cubic-inch water guns fired 

at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
Results for Water Pressure and Ground Vibrations 25

mad16-1648_fig24

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

EXPLANATION

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 24. Pressure measurements at a depth of 4 feet below water surface from two 80-cubic-inch water guns fired 

at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

EXPLANATION

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 25. Pressure measurements at a depth of 6 feet below water surface from two 80-cubic-inch water guns fired 

at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
26 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig26

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

EXPLANATION

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 26. Pressure measurements at a depth of 8 feet below water surface from two 80-cubic-inch water guns fired 

at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,046,820 1,046,840 1,046,860 1,046,880 1,046,900

1,761,260

1,761,280

1,761,300

1,761,320

1,761,340

Pressure, in pounds per square inch

5 pounds per square inch

 contour line

Water gun

Hydrophone group position

EXPLANATION

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 27. Pressure measurements at a depth of 9 feet below water surface from two 80-cubic-inch water guns fired 

at 1,000 pounds per square inch, Brandon Road study, Des Plaines River, near Joliet, Illinois.
Results for Water Pressure and Ground Vibrations 27

mad16-1648_fig28

NW SE

A

5 7 9

11

11

13

13

15

15

17

17

19

19

21

21

23

23

25

25

27

27

29

29

31

31

33

33

35

35

37 39

-8

-6

-4

-2

0

-8

-6

-4

-2

0

B

Distance from testing wall, in feet

Depth, in feet

Depth, in feet

EXPLANATION

Pressure, in pounds

 per square inch

11.5

11.0

12.0

10.5

10.0

9.5

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Hydrophone

 position

5 pounds per square

 inch contour line

Figure 28. Spatial distribution of pressure for a single 80-cubic-inch water gun 6 feet below water surface fired at 700 

pounds per square inch (A), and for two 80-cubic-inch water guns 6 and 8 feet below water surface fired at 1,000 pounds per 

square inch (B), Brandon Road study, Des Plaines River, near Joliet, Illinois.

Brandon Road Ground Vibrations

Velocities on land surface were measured using 3C 

geophones placed near the testing wall (figs. 5–8), and are 

referred to as wall velocities. Velocities in these scenarios 

ranged from background velocities of less than 0.005 in/s to 

the maximum recorded velocity of 0.239 in/s. All velocities 

were less than the stated threshold of 0.75 in/s. Directionally, 

the maximum velocities recorded during the experiment 

were 0.239 in/s of vertical velocity and 0.122 in/s of 

horizontal velocity.

Varying Gun Distance Scenario

This scenario was run as a series of increasing pressure 

tests at decreasing gun distances to determine the operational 

limits of the water guns in the confined space of the channel as 

defined by the USACE. Geophones were placed in three pairs, 

with one pair of R.T. Clark geophones collocated with one pair 

of Instantel geophones as shown in figure 5, at 0, 10, and 20 ft 

from the center line formed by the hydrophone boom and the 

gun platform at distances of 6 and 16 ft perpendicular to the 

testing wall.
28 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Velocity generally increases linearly in all components 

as gun distance from the wall decreases (fig. 29). The vertical 

component of the geophone placed 16 ft from the wall edge 

is an exception to this trend. However, the magnitude of the 

velocity increase is small—less than 0.01 in/s in most cases.

Other Scenarios

After the varying gun distance scenario, the water gun 

or guns were fixed in position relative to the testing wall 

(55 ft from the wall) for the remaining scenarios. Because of 

the repeatability of the water gun seismic signals, geophone 

locations were changed after sufficient data collection at each 

point location. The water gun or guns remained fixed spatially 

for most of the scenarios, allowing multiple geophone 

configurations for a more detailed coverage of the velocity 

response of the area behind the canal wall (figs. 6–8).

As shown in figure 30, velocity from geophone locations 

increases linearly with water gun input pressure in all 

components (transverse, longitudinal, and vertical velocity 

components). In all shots where the water gun or guns were 

55 ft from the wall, the highest velocities were recorded on 

the vertical component of the geophone placed farthest from 

the channel, with velocity changes of 0.1 in/s occurring there. 

Longitudinal and transverse velocities were 50 percent or less 

of the vertical component velocities, and velocities for these 

two horizontal components were roughly equivalent between 

the two geophones at 6 and 16 ft from the wall. 

Differences between the 6-ft gun with gun ports aligned 

perpendicularly to the wall and the 8-ft gun with gun ports 

aligned parallel to the wall are shown in figure 31. Varying 

gun depth and gun port orientation result in differences of 

velocity of less than 10 percent.

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0.080

40 45 50 55 60

Wall velocity, in inches per second 

Gun distance from wall, in feet

EXPLANATION

6 feet transverse

6 feet longitudinal

6 feet vertical

16 feet transverse

16 feet longitudinal

16 feet vertical

Geophone distance from wall

 and velocity component

Figure 29. Changes in velocity at geophones 

placed 6 and 16 feet from testing wall in transverse, 

longitudinal, and vertical components, Brandon Road 

study, Des Plaines River, near Joliet, Illinois.

EXPLANATION

6 feet transverse

6 feet longitudinal

6 feet vertical

16 feet transverse

16 feet longitudinal

16 feet vertical

Geophone distance from wall

 and velocity component

0.000

0.020

0.040

0.060

0.080

0.100

0.120

0.140

0.160

0.180

0.200

500 1,000 1,500 2,000

Wall velocity, in inches per second 

Water gun pressure, in pounds per square inch

Figure 30. Changes in velocity with varying water 

gun pressure, Brandon Road study, Des Plaines 

River, near Joliet, Illinois. Wall velocities in the 

transverse, longitudinal, and horizontal directions 

are shown.
Results for Water Pressure and Ground Vibrations 29

Vertical velocities decreased with distance by about 

25 percent as geophones were moved from the center line 

out to a distance of 60 ft, as shown in figure 32. Based on a 

regression analysis using the three data points in figure 32

(eq. 1; coefficient of determination 0.97), the vertical 

component velocity is estimated to decrease to less than 

0.01 in/s at a distance of 428 ft along the wall. Transverse 

and longitudinal velocities do not show a defined trend, with 

longitudinal velocities varying by less than 10 percent and 

transverse velocities fluctuating with no defined trend.

Y e X = − 0 0852 0 005 . .

(1)

where

Y is the value of wall velocity in inches per 

second,

x is the horizontal distance along the wall in 

feet, and

e is the natural logarithm.

Differences in velocity at distances of 6 and 16 feet 

inland from the wall from firing a single water gun compared 

to two water guns are shown in figure 33. Adding a second 

gun and firing at the same pressure results in an increase in 

velocity of the wall, with the proportion of increase varying 

by directional component. The vertical component increased 

by 60 percent compared to a single gun firing. The horizontal 

components (longitudinal and transverse) show a smaller 

amount of increase from the second gun, but vary with the 

location of the geophone in relation to distance from the edge 

of the wall.

0.000

0.020

0.040

0.060

0.080

0.100

0.120

6 feet

transverse

6 feet

longitudinal

6 feet

vertical

16 feet

transverse

16 feet

longitudinal

16 feet

vertical

Wall velocity, in inches per second 

Geophone distance from wall and velocity component

8-foot gun

EXPLANATION

6-foot gun

Figure 31. Transverse, longitudinal, and vertical wall 

velocities of pressure waves from firing of two 80-cubicinch water guns fired at 1,000 pounds per square inch at 

depths of 6 and 8 feet below water surface, respectively, 

as measured by geophones 6 and 16 feet inland from 

wall, Brandon Road study, Des Plaines River, near Joliet, 

Illinois. The 6-foot gun had ports aligned perpendicular 

to the wall, whereas the 8-foot gun had ports aligned 

parallel to the wall.

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0.080

0.090

0.100

0 10 60

Wall velocity, in inches per second 

Distance from centerline, in feet

EXPLANATION

Transverse

Longitudinal

Vertical

Geophone velocity

 component

Figure 32. Transverse, longitudinal, 

and vertical wall velocities of 

pressure waves from firing of two 

80-cubic-inch water guns at 6 

and 8 feet below water surface, 

respectively, as measured by three 

three-component geophones placed 

6 feet from edge of channel at 

various offsets from the center line 

of experiment, Brandon Road study, 

Des Plaines River, near Joliet, Illinois.
30 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig33

0.000

0.020

0.040

0.060

0.080

0.100

0.120

0.140

0.160

0.180

0.200

6 feet

transverse

6 feet

longitudinal

6 feet

vertical

16 feet

transverse

16 feet

longitudinal

16 feet

vertical

Wall velocity, in inches per second 

Geophone distance from wall and velocity component

Two water guns

Single water gun

EXPLANATION

Figure 33. Transverse, longitudinal, and vertical wall 

velocities of pressure waves from firing of a single 

80-cubic-inch water gun and two 80-cubic-inch water 

guns at depths of 6 and 8 feet below water surface, 

respectively, and all fired at 1,000 pounds per square 

inch, as measured by geophones 6 and 16 feet inland 

from wall, Brandon Road study, Des Plaines River, near 

Joliet, Illinois.

Acceleration

Acceleration data were collected by two singlecomponent accelerometers mounted on top of the canal 

wall. Accelerometer positions remained fixed. Acceleration 

rates ranged from 0.0002 to 0.0188 ft/s2 over the duration of 

the experiment. The maximum acceleration rates recorded 

were 0.0188 ft/s2 in an upward direction, and the maximum 

horizontal acceleration was 0.0123 ft/s2 in a direction towards 

the channel (out of the canal wall).

Change in acceleration as the gun input pressure changes 

are shown in figure 34. These graphs are a combination of 

data collected over the entire setup that used a single water 

gun at a depth of 6 ft bws. Five water gun shots were taken at 

each point location. For each shot, the maximum value was 

recorded. The arithmetic mean of the five maximum values 

was used to generate the figures in this report. Processed 

location data were integrated with the average maximum 

values recorded by the accelerometers. For both components, 

the acceleration increases with increasing gun pressure.

Lemont Water Pressure

2011 Replicate Scenario

In this scenario, we evaluated the operational limits of 

the water guns in the CSSC by decreasing distances between 

the water gun or guns and the canal testing wall. Pressure data 

were collected on two hydrophone strings (18 hydrophones 

total) suspended from two buoys at distances of 5 and 15 ft 

from the wall. Water guns were set at depths of 4 and 14 ft 

and fired separately, and then both water guns were fired 

simultaneously. Water guns originally were set at 90 ft from 

the testing wall and moved in 10-ft increments until they were 

40 ft from the testing wall.

Variations in pressure as monitored by three 

representative hydrophones at depths of 4, 14, and 22 ft bws 

on the buoy mounted 5 ft from the testing wall are shown 

in figure 35. All hydrophone depths show a similar trend of 

linearly increasing pressure as the water guns approach the 

wall at 40 ft. Pressure then decreases at 30 ft for the 14- and 

22-ft hydrophones, but continues to increase for the 4-ft 

hydrophone. Factors that could cause this change include 

distance to wall boundary conditions or asymmetry of the 

pressure field immediately surrounding the gun.

Pressures from the 22-ft hydrophone are higher than 

pressures from the 4- and 14-ft hydrophones from 90- to 

40-ft distances and for all configurations. Data collected 

at 30 ft indicate a decrease in pressure from the 22-ft and 

14-ft hydrophones relative to previous data collected at 40 ft 

in contrast to a general decrease in pressures with greater 

distance from the testing wall. The pressures for the 4-ft 

hydrophone at 30 ft are lower or higher relative to the 22-ft 

hydrophone data, depending on operations of the water guns. 

The pressures for the 14-ft hydrophone are slightly higher 

than pressures for the 4 ft hydrophone at distances of 40 ft and 

greater, but are less at a distance of 30 ft. 

At a distance of greater than 40 ft, the magnitudes of the 

pressures from two guns (fig. 35A) and the 14-ft gun (fig. 35C) 

are similar (<10 percent variation). Pressures from the 4-ft gun 

(fig. 35B) are 10–15 percent lower at each distance compared 

to either the two guns or the 14-ft gun. The 5-lb/in3 threshold 

was reached at all three hydrophone depths when the water 

gun was 60 ft from the wall during the firing of both guns 

together and also during the firing of the 14-ft single gun. 

However, the 4-ft single gun reached the 5 lb/in3 threshold 

when the water gun was 50 ft from the wall.
Results for Water Pressure and Ground Vibrations 31

mad16-1648_fig34 Acceleration, in feet per square second

0 500 1,000 1,500 2,000 2,500

Water gun pressure, in pounds per square inch

B. Horizontal

A. Vertical

-0.05

0

0.05

0.1

0.15

0.2

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

Down

Up

EXPLANATION

Into the canal wall

Out of the canal wall

EXPLANATION

Figure 34. Acceleration of pressure wave velocities as water gun input 

pressure increases in vertical (A) and horizontal (B) directions, Brandon 

Road study, Des Plaines River, near Joliet, Illinois.
32 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig35

0

2

4

6

8

10

12

14

A. Both guns

0

2

4

6

8

10

12

14

Pressure, in pounds per square inch 

B. 4-foot gun/gun 2

0

2

4

6

8

10

12

14

30 40 50 60 70 80 90

Water gun distance from testing wall, in feet

C. 14-foot gun/gun 1

4 foot

14 foot

22 foot

EXPLANATION Figure 35. Pressure measurements at depths of 

4, 14, and 22 feet below water surface from two 

80-cubic-inch water guns (A), a single 80-cubic-inch 

water gun suspended at a depth of 4 feet below 

water surface (B), and a single 80-cubic-inch water 

gun suspended at a depth of 14 feet below water 

surface (C), and all fired at 2,000 pounds per square 

inch at distances of 30 to 90 feet from the testing wall, 

Chicago Sanitary Ship Channel, near Lemont, Illinois.

Double Gun Grid Scenario

The double gun grid scenario involved recording 

pressures surrounding two 80-in3 water guns placed at 

distances of 40 ft and 120 ft, respectively, from the north wall. 

Both water guns were set at a depth of 14 ft bws. The first trial 

collected data at a gun input pressure of 2,000 lb/in2. Pressure 

data were collected from the firing of one water gun, and then 

from the simultaneous firing of two water guns.

Pressure maps for three separate depths (figs. 36–41) 

show variations for depth above, below, and at the level of 

the water guns. The 5-lb/in2

 threshold pressure extended 

across most of the measured area, with depths below the 

water gun depth showing the greatest radial pressure extent 

encompassing the entire measured area. Pressures decrease 

with increasing radius from the water gun location. Pressures 

at 14 ft (gun depth) were lower than pressures recorded either 

near the surface or at the bottom of the canal. This change in 

the shape of the pressure may be caused by a more spatially 

extensive environment.
Results for Water Pressure and Ground Vibrations 33

mad16-1648_fig36

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

5 pounds per square

 inch contour line

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 36. Pressure measurements at a depth of 6 feet below water surface from a single 80-cubic-inch water gun fired at 

2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
34 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig37

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

5 pounds per square

 inch contour line

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 37. Pressure measurements at a depth of 6 feet below water surface from two 80-cubic-inch water guns both 

fired at 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 35

mad16-1648_fig38

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

5 pounds per square

 inch contour line

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 38. Pressure measurements at a depth of 14 feet below water surface from a single 80-cubic-inch water gun fired 

at 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
36 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig39

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

5 pounds per square

 inch contour line

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 39. Pressure measurements at a depth of 14 feet below water surface from two 80-cubic-inch water guns both fired 

at 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 37

mad16-1648_fig40

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 40. Pressure measurements at a depth of 22 feet below water surface from a single 80-cubic-inch water gun fired 

at 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
38 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig41

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 41. Pressure measurements at a depth of 22 feet below water surface from two 80-cubic-inch water guns both 

fired at 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.

There was not a very noticeable difference in the canal 

pressure fields between firing one and both water guns. The 

magnitude of differences at all depths between two water guns 

and a single, 14-ft water gun was 5 and 10 percent—similar to 

the 2011 replicate scenario.

The second trial was done with a lower gun input 

pressure (1,000 lb/in2) than the first trial (2,000 lb/in2). Pressure 

data were collected from firing two 80-in3 water guns placed 

in the same linear configuration 40 ft and 120 ft from the 

testing wall, with the guns set at a depth of 14 ft bws.

The results from this trial (figs. 42–47) indicated trends 

similar to those of the double gun grid high pressure trial: The 

largest pressures were below the gun depth, and pressures 

from 14 ft bws (the gun depth) were lower than pressures 

from above (6 ft bws) or below (22 ft bws) the gun depth. A 

generally radial pattern with pressure decreasing away from 

the water gun location is indicated for all data collected. In 

the low pressure trial, the 5 lb/in2 threshold pressure was 

not exceeded at any location on any of the pressure maps, 

in contrast to the high pressure trial, in which the threshold 

pressure was exceeded at most locations. There was a large 

disparity in the radius of the 5 lb/in2 zone between the high 

and low pressure trials, as well as a clearer distinction between 

single gun firings and double gun firings during the low 

pressure trial that was not observed in the high pressure trial. 

This indicates that water gun input pressure likely plays a 

larger role in determining the extent of the water gun pressure 

field in this environment than the configuration of single or 

double guns.
Results for Water Pressure and Ground Vibrations 39

mad16-1648_fig42

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 42. Pressure measurements at a depth of 6 feet below water surface from a single 80-cubic-inch water gun fired at 

1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
40 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig43

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 43. Pressure measurements at a depth of 6 feet below water surface from two 80-cubic inch water guns both fired 

at 1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 41

mad16-1648_fig44

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 44. Pressure measurements at a depth of 14 feet below water surface from a single 80-cubic-inch water gun fired 

at 1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
42 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig45

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 45. Pressure measurements at a depth of 14 feet below water surface from two 80-cubic-inch water guns fired at 

1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 43

mad16-1648_fig46

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 46. Pressure measurements at a depth of 22 feet below water surface from a single 80-cubic-inch water gun fired 

at 1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.
44 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig47

Illinois State Plane East, Zone 1201, easting, in feet

Illinois State Plane East, Zone 1201, northing, in feet

1,080,980 1,081,000 1,081,020 1,081,040 1,081,060

1,828,340

1,828,360

1,828,380

1,828,400

1,828,420 EXPLANATION

Water gun

Hydrophone group

 position

Pressure, in pounds

 per square inch

19

20

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Figure 47. Pressure measurements at a depth of 22 feet below water surface from two 80-cubic-inch water guns both fired 

at 1,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, Illinois.

Lemont Ground Vibrations

Velocity was measured using surface three-component 

geophones, as at Brandon Road. Additionally, velocity was 

measured using three-component downhole geophones. 

Geophones were placed 5, 35, and 100 ft away from the canal 

wall for the 2011 replicate scenario, and 5 and 15 ft away from 

the canal wall for the double gun grid scenario. In the double 

gun grid scenario, geophones were placed in line and offset 

from the center line. The surface geophones were oriented 

such that the longitudinal component of each geophone case 

was pointing directly away from the canal, perpendicular 

to the walls.

Velocities in both scenarios ranged from background 

velocities of less than 0.005 in/s to the maximum recorded 

velocity of 0.304 in/s. All velocities were less than the 

stated sensitive machinery limit threshold of 0.75 in/s. 

Directionally, the maximum velocities recorded were 

0.304 in/s in the vertical component and 0.122 in/s in the 

horizontal component.

2011 Replicate Scenario

This scenario involved collecting data with decreasing 

distance from the water gun to the canal wall to determine 

how velocity measured near the canal wall changed as water 

gun distance decreased. Velocity data were collected by 
Results for Water Pressure and Ground Vibrations 45

downhole (at depths of 5 ft [shallow] and 20–25 ft [deep] 

bgs) and surface geophones. The geophones were placed at 

the borehole locations 5 and 35 ft from the canal in a transect 

about 15 ft downstream of the water gun center line (fig. 9A). 

The surface geophone placed 5 ft landward from the 

right bank canal wall recorded larger velocities at each water 

gun depth and double gun shot compared to the surface 

geophone placed 35 ft landward from the canal wall (fig. 48). 

This velocity trend also is present in the borehole geophones. 

The 5-ft borehole geophones recorded higher vertical 

component velocities than the 35-ft borehole geophones 

during single and double gun shots. Surface velocities 

generally are higher than borehole velocities because the 

boreholes are confined by rock on all sides, making movement 

more difficult. The deep borehole geophones recorded higher 

velocities than the shallow borehole geophones (fig. 49). This 

velocity difference is more pronounced at the 5-ft borehole 

and decreases as distance from the water gun increases. The 

deep geophones likely have higher velocities than the shallow 

borehole geophones because the deep borehole geophones are 

placed at relatively the same elevation as the water gun placed 

14 ft bws—closer than the shallow borehole geophone.

There also is a change in which component (transverse, 

longitudinal, or vertical) recorded the highest velocity. At 

the surface geophone placed 5 ft from the canal wall, the 

longitudinal component recorded the highest velocities, 

whereas at the surface geophone placed 35 ft from the 

canal wall, the vertical component recorded the highest 

velocities (fig. 48).

Transverse Longitudinal Vertical

Geophone component

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

Velocity, in inches per second

EXPLANATION

5-foot surface geophone, east gun

35-foot surface geophone, east gun

5-foot surface geophone, west gun

35-foot surface geophone, west gun

5-foot surface geophone, both guns

35-foot surface geophone, both guns

Figure 48. Highest velocities from water guns recorded by surface geophones during the 

2011 replicate scenario for water guns placed 30 feet from the canal wall and fired at an 

input pressure of 2,000 pounds per square inch, Chicago Sanitary Ship Channel, near Lemont, 

Illinois.

East gun West gun Both guns

Velocity, in inches per second

Water gun fired

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18 EXPLANATION

5-foot surface geophone

5-foot shallow borehole geophone

5-foot deep borehole geophone

35-foot surface geophone

35-foot shallow borehole geophone

35-foot deep borehole geophone

100-foot shallow borehole geophone

100-foot deep borehole geophone

NOTE: Shallow, 5 feet below ground surface; 

deep, 20–25 feet below ground surface.

Geophone distance from canal wall

Figure 49. Highest vertical velocities from water guns recorded by surface and downhole 

geophones during the 2011 replicate scenario for water guns placed 30 feet from the canal wall 

and fired at an input pressure of 2,000 pounds per square inch, Chicago Sanitary Ship Channel, 

near Lemont, Illinois.
46 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Double Gun Grid Scenario

This scenario was run as a series of water gun shots 

with geophones placed in line and offset from the center line 

to determine how velocities varied with changing distance 

parallel to the canal wall. Velocity data were collected by 

surface geophones placed in a line with 10 ft of separation 

(fig. 10A) and downhole geophones in the boreholes 5 and 

35 ft landward from the right bank canal wall. The center of 

the geophone line (between the white and green geophones) 

was aligned with the water guns so that offset geophones were 

15 ft upstream (pink) and 15 ft downstream (red) and “in line” 

geophones were 5 ft upstream (white) and 5ft downstream 

(green) of the water guns (fig. 10A). The 15-ft downstream 

(red) surface geophone remained next to the 5-ft landward 

borehole for quality assurance control between the 2011 

replicate and double gun grid scenarios.

The highest recorded velocities were from the vertical 

component of the pink geophone (fig. 50) placed 15 ft 

upstream of the center line. Here, the maximum velocity 

measured was 0.304 in/s from the firing of two water guns 

placed 40 and 120 ft from the canal wall at 2,000 lb/in2

. 

This was the highest velocity measured on the canal wall 

between all three scenarios. Geophones of equal distance from 

the water gun center (pink and red, white and green) were 

examined to determine if they recorded similar velocities. In 

theory, geophones placed the same distance from the center 

line should record similar velocities. These velocity data 

were from data collected when the water gun was 40 ft from 

the canal wall (fig. 50). Geophones placed the same distance 

from the center line did not produce similar velocities. The 

pink (15 ft upstream of center) geophone recorded the highest 

velocities compared to the other three geophones; the pink 

geophone recorded higher velocities compared to the red 

geophone (both 15 ft downstream of center), and the white 

geophone recorded higher velocities compared to the green 

geophone (both 5 ft downstream of center).

The maximum horizontal (transverse and longitudinal) 

velocities recorded at the red surface geophone placed 5 ft 

from the canal wall are not as consistent as the maximum 

vertical velocities. Horizontal velocities vary by about 

0.04 in/s with a ranges of about 0.09–0.13 and 0.12–0.16 in/s 

for the transverse and longitudinal horizontal velocities, 

respectively. Vertical velocities vary by 0.01 in/s with a range 

of 0.09–0.10 in/s. The borehole geophones recorded similar 

velocities between the scenarios compared to the surface 

geophones from a shot 40 ft from the canal wall firing at a gun 

input pressure of 2,000 lb/in2 (fig. 51). The maximum recorded 

velocities at the surface geophone do not always occur 

during the single gun firing. A double gun firing produced the 

maximum velocity for the vertical component.

-20 -15 -10 -5 0 5 10 15 20

Velocity, in inches per second

Geophone offset from line to gun platform center line, in feet

Upstream Downstream

Pink transverse

Pink longitudinal

Pink vertical

White transverse

White longitudinal

White vertical

Green transverse

Green longitudinal

Green vertical

Red transverse

Red longitudinal

Red vertical

EXPLANATION

Pink

White Green

Red

0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

Figure 50. Geophone positions along the canal wall relative to water gun center line and velocities recorded at each 

position from a water gun fired about 40 feet from the wall at a depth of 14 feet below water surface, Chicago Sanitary 

Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 47

mad16-1648_fig51

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Transverse Longitudinal Vertical

Velocity, in inches per second

Geophone component

A 

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Lemont replicate Double gun high pressure

Double gun grid

B

Lemont replicate

Double gun grid high pressure

5-foot shallow borehole geophone

5-foot deep borehole geophone

35-foot shallow borehole geophone

35-foot deep borehole geophone

EXPLANATION

EXPLANATION

Figure 51. Maximum velocities recorded for the 2011 replicate scenario and the 

double gun grid scenario high pressure trial by the red surface geophone placed 

5 feet from the canal wall (A) and borehole geophones (B) placed 5 and 35 feet from 

the canal wall, Chicago Sanitary Ship Channel, near Lemont, Illinois.

The double gun grid scenario low pressure trial was run 

with the same water gun setup as the double gun grid scenario 

high pressure trial, but with the water gun input pressure 

decreased to 1,000 lb/in2. The geophone placements were 

changed, resulting in an L-shaped grid with 10 ft of separation 

(fig. 10B) so that comparisons could be made to the Brandon 

Road Lock and Dam data sets setup in a grid with 10 ft of 

separation. The water guns were centered in the middle of the 

channel so that the white and blue geophones were placed 5 ft 

upstream of the center line and the green and pink geophones 

were placed 5 ft downstream of the center line. The center of 

the grid formed by these four geophones made a perpendicular 

line relative to the canal wall. The red surface geophone 

remained next to the 5-ft borehole 15 ft downstream of the 

center line for quality assurance control between the scenarios. 

The velocity differences between a typical single 

1,000 and 2,000 lb/in2 water gun shot fired 40 ft from the 

canal wall and recorded at the red surface geophone placed 

15 ft downstream and 5 ft from the canal wall are shown 

in figure 52. The peak ground velocity decreases with the 

decrease in gun input pressure, but not proportionally.

Velocities recorded at each geophone in the grid 

(fig. 10B) from the firing of a single water gun 40 ft from 

the canal wall at an input pressure of 1,000 lb/in2 are shown 

in figure 53. The blue geophone (5 ft upstream of and 15 ft 

landward from wall) recorded the highest vertical component 

velocity, and the green geophone (5 ft downstream of and 

5 ft landward from wall) recorded the highest longitudinal 

component velocity. 
48 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig52

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

1,000 2,000

Velocity, in inches per second

Pressure, in pounds per square inch

Transverse

Longitudinal

Vertical

EXPLANATION

Figure 52. Transverse, longitudinal, and vertical velocities of a single water gun with 

input pressures of 1,000 and 2,000 pounds per square inch placed 40 feet from the canal 

wall, as measured by the red surface geophone placed 15 feet downstream of the 

center line and 5 feet from the canal wall, Chicago Sanitary Ship Channel, near Lemont, 

Illinois.

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Transverse Longitudinal Vertical

Velocity, in inches per second

Geophone Component

EXPLANATION

White

Green

Blue

Pink

Geophones

Figure 53. Transverse, longitudinal, and vertical velocities of a single water gun with 

input pressure of 1,000 pounds per square inch placed 40 feet from the canal wall and 

14 feet below water surface, as measured by surface geophones placed 5 and 15 feet from 

the canal wall and offset either 5 feet upstream (white and blue) or 5 feet downstream 

(green and pink) of the water gun, Chicago Sanitary Ship Channel, near Lemont, Illinois.
Results for Water Pressure and Ground Vibrations 49

Acceleration

Acceleration data were collected by two singlecomponent (horizontal and vertical) accelerometers mounted 

on the wall of the canal. The accelerometers were placed 

directly in line with the water guns, with the horizontal unit 

monitoring the movement of the wall directly toward or away 

from the canal (longitudinal component) and the vertical unit 

monitoring the movement of the wall up and down (vertical 

component). The two accelerometers were attached to an 

aluminum mounting block secured to the dolomite setblock 

wall about 2 ft down from the top of the wall and about 5–6 ft 

above the water. These sensors remained in the same position 

throughout the duration of the study.

Vertical acceleration upward and horizontal acceleration 

out of the canal wall decreased with decreasing distance to the 

wall, with a sharp decrease in acceleration towards zero at shot 

distances of 40–60 ft (fig. 54). Vertical acceleration downward 

and horizontal acceleration into the canal wall increased with 

decreasing distance from the wall, with a sharp change in 

acceleration towards zero at shot distances of 40–60 ft. Some 

possibilities for these small acceleration rates may be poor 

coupling of the block into the dolomite, or poor coupling 

into the weathered/weak dolomite. Acceleration rates into the 

canal wall and downward produced almost a mirror image of 

their positive counterparts, but with a smaller range of values 

(0.025 ft/s2 compared to 0.153 ft/s2). These were trends for 

both single gun shots as well (data not shown); however, 

double gun shots produced almost double acceleration rates 

out of the wall and upward compared to single gun shots. 

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

Acceleration, in feet per square second

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0 20 40 60 80 100

Shot distance from canal wall, in feet

B

A

EXPLANATION

Up

Down

EXPLANATION

Out of the canal wall

Into the canal wall

Figure 54. Changes in acceleration of pressure wave velocities as water 

gun distance to the canal wall decreases for the vertical (A) and horizontal 

(B) components of a double gun firing 40 and 120 feet from the canal wall, 

Chicago Sanitary Ship Channel, near Lemont, Illinois.
50 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Acceleration rates into the wall as well as downward between 

single gun and double gun firings were relatively similar. The 

maximum recorded acceleration rates were a 0.15 ft/s2 vertical 

upward movement and a 0.15 ft/s2 horizontal movement out of 

the wall when two water guns placed 80 ft from the canal wall 

were fired simultaneously. Changes in acceleration as water 

gun distance decreases firing both water guns at 2,000 lb/in2

are shown in figure 54. Five water gun shots were taken at 

each point location. For each shot, the maximum acceleration 

rate was recorded (data were logged every 0.0625 millisecond 

for 3 s following firing). The arithmetic mean of the five 

maximum acceleration rates was recorded at each position.

Comparison of Hydrophone Data from 

Different Water-Gun Configurations

These two studies measured the underwater pressure field 

created by a water gun or water guns within two navigable 

water channel environments. The channel to the Brandon Road 

Lock and Dam has about one-half the depth and two-thirds the 

width of the segment of the CSSC near Lemont. The channel 

geometry and construction are similar, however. Both channels 

are artificially constructed with a rectangular cross section 

and walls made of imported building materials (concrete at 

Brandon Road and dolomite setblock at Lemont).

The operational parameters also had similarities and 

differences. Lower firing pressures due to limitations set 

by USACE engineers resulted in the restriction of input 

pressure from the Brandon Road single gun radial trial gun to 

700 lb/in2 compared to the setting of input pressure from the 

Lemont single gun trial at 1,000 lb/in2. Water guns were fired 

at Brandon Road at 2,000 lb/in2, but only five times. Water gun 

positions were limited by channel size. Water guns could only 

be moored together at Brandon Road to maintain maximum 

distance from both walls, whereas at Lemont, water guns had 

to be moored separately to cover the wider channel.

Pressure and distance comparisons for single water guns 

fired at 1,000 lb/in2

 at Brandon Road and at Lemont are shown 

in figure 55. These values represent the three-dimensional 

distance from the water gun or guns to the hydrophone. 

The three-dimensional distance was calculated using the 

Pythagorean Theorem to determine the length of the line 

segment drawn directly from the centroid of the water gun 

location to the centroid of the hydrophone location in question. 

In the case of multiple water guns, data at Brandon Road were 

measured from the midpoint between the co-located water 

guns, and data from Lemont always were measured from 

the easternmost water gun (restrictions in hydrophone cable 

length resulted in a greater data density surrounding this gun). 

Data from Brandon Road (fig 55A) follow an approximate 

exponential trend of decreasing pressure with distance. 

Relative pressure variation between the hydrophones also 

decreases with distance from the water gun, with the highest 

pressures nearest the bottom of the channel and the lowest 

pressures at the water surface. Data from Lemont (fig. 55B) 

likely were recorded at a distance beyond the inflection point 

of the exponential trend observed at Brandon Road and also 

were beyond the point at which the intensity with depth 

relation normalizes.

Data recorded at comparable distances (20–50 ft) showed 

two different trends. Data from Brandon Road decreased 

from about 3 lb/in2 to 1 lb/in2, whereas data from Lemont 

remained static at about 3 lb/in2. Given that these water guns 

were placed in roughly the same relative position (the same 

proportional distance from the testing wall and with the 

water gun suspended at about the mid-depth of the channel), 

additional depth present at Lemont (about 9 ft of water below 

the water gun as compared to about 3 ft at Brandon Road) may 

result in a smaller loss of pressure. 

Pressure and distance comparisons for two water guns 

fired at 1,000 lb/in2

 are shown in figure 56. For these trials, the 

water guns were fired at the same pressure, but were deployed 

differently. At Brandon Road, the water guns were moored 

together with the guns suspended at 6 and 8 ft bws, whereas at 

Lemont, the two platforms were separated by 80 ft with both 

water guns suspended at 14 ft bws. 

Trends in pressure over distance were similar to the 

single gun data discussed earlier in this section. Data from 

Brandon Road (fig. 56A) showed an exponential trend of 

decreasing pressure with distance, whereas data from Lemont 

(fig. 56B) showed static pressure with distance. Over a 

comparable distance (40–60 ft), pressures at Brandon Road 

decreased from 6 to 3 lb/in2

, whereas pressures at Lemont 

remained constant at 3 lb/in2. 

The addition of a second water gun was more apparent at 

Brandon Road. The maximum pressure recorded was nearly 

double that of the single gun data. The extent of the 5-lb/in2

contour doubled from 20 to 40 ft. 

Pressures at Lemont indicated that, although the intensity 

of this water gun deployment was lower than the pressures 

at Brandon, the range at which the target pressure can be 

projected is larger. Pressures at Lemont remained constant 

from 20 ft until at least 85 ft, whereas pressures at Brandon 

trended toward 0 at 55 ft. 

This tradeoff of initial intensity compared to greater 

range likely is the result of the water gun configuration. The 

location of water guns close to each other seemingly resulted 

in an increase in the intensity close to the gun, but only a small 

increase in the range. Increasing the distance between the 

water guns showed the reverse—a decrease in initial intensity, 

but an increase in range. 
Comparison of Hydrophone Data from Different Water-Gun Configurations 51

mad16-1648_fig55

0

1

2

3

4

5

6

7

8

9

10

Pressure, in pounds per square inch

0

1

2

3

4

5

6

7

8

9

10

10 15 20 25 30 35 40 45 50 55

Three-dimensional distance, in feet

A

B

0 feet

2 feet

4 feet

6 feet

8 feet

9 feet

EXPLANATION

6 feet

14 feet

22 feet

EXPLANATION

Figure 55. Changes in water pressure as three-dimensional distance from water 

guns(s) to hydrophone increases when firing one 80-cubic-inch water gun at 

1,000 pounds per square inch at (A) Brandon Road study area, Des Plaines River, 

near Joliet, Illinois; and (B) Lemont study area, Chicago Sanitary Ship Channel, 

near Lemont, Illinois.
52 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

mad16-1648_fig56 Pressure, in pounds per square inch

Three-dimensional distance, in feet

A

B

0

2

4

6

8

10

12

14

16

18

20

0

2

4

6

8

10

12

14

16

18

20

10 20 30 40 50 60 70 80 90

0 feet

2 feet

4 feet

6 feet

8 feet

9 feet

EXPLANATION

6 feet

14 feet

22 feet

EXPLANATION

Figure 56. Changes in water pressure as three-dimensional distance from 

water guns to hydrophone increases when firing two 80-cubic-inch water guns at 

1,000 pounds per square inch at (A) Brandon Road study area, Des Plaines River, 

near Joliet, Illinois; and (B) Lemont study area, Chicago Sanitary Ship Channel, 

near Lemont, Illinois.
Comparison of Hydrophone Data from Different Water-Gun Configurations 53

This conclusion is corroborated by data from the 2011 

replicate scenario at Lemont and the Brandon Road double 

gun radial scenario. Data collected at Lemont are shown in 

figure 35A and C. Comparing the values from a single gun at 

14 ft bws and both guns at 4 and 14 ft bws, there was only a 

small increase in the pressure recorded despite the addition 

of a second water gun firing at 2,000 lb/in2. Data collected 

at Brandon are shown in figure 20A and C. The addition of a 

second water gun did not result in a substantial change in the 

extent of the 5-lb/in2 contour. 

Pressure and distance comparisons from two water 

guns fired at 2,000 lb/in2 are shown in figure 57. Data from 

Brandon Road (fig. 57A) are similar to previous iterations at 

different pressures. Data from Lemont (fig 57B) are slightly 

different from data of the two previous examples (figs. 55B

and 56B). Pressures show a decreasing linear trend over 

distance compared to the nearly static relation shown in the 

1,000-lb/in2 trials. Trends in figure 57B are more similar to 

those in figures 55A and 56A, indicating the decaying limb of 

the exponential trends shown in those examples. The increase 

in firing pressure possibly results in a higher intensity near the 

gun and the similarities to the trends shown in the Brandon 

Road data.

Pressure, in pounds per square inch

Three-dimensional distance, in feet

A

B

0

5

10

15

20

25

30

0

5

10

15

20

25

30

10 20 30 40 50 60 70 80 90

0 feet

2 feet

4 feet

6 feet

8 feet

9 feet

EXPLANATION

6 feet

14 feet

22 feet

EXPLANATION

Figure 57. Changes in water pressure as three-dimensional distance from 

water guns to hydrophone increases when firing two 80-cubic-inch water guns 

at 2,000 pounds per square inch at (A) Brandon Road study area, Des Plaines 

River, near Joliet, Illinois; and (B) Lemont study area, Chicago Sanitary Ship 

Channel, near Lemont, Illinois.
54 Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois

Summary

Two species of invasive Asian carps (bighead carps 

[Hypophthalmichthys nobilis] and silver carps [Hypophthalmichthys molitrix]) have the potential to move into the Great 

Lakes from the Mississippi River Basin. The U.S. Geological 

Survey (USGS), in cooperation with the U.S. Environmental 

Protection Agency, Great Lakes Restoration Initiative, 

is evaluating the underwater pressure field and ground 

vibrations produced from the firing of a seismic water gun 

and its potential effectiveness of producing a pressure barrier 

to prevent or direct the movement of the Asian carps while 

ensuring the integrity of surrounding structures. Underwater 

pressure data were collected by blast-rated hydrophones and 

blast sensors. Velocity and acceleration data at structures 

adjacent to the water guns were collected by three-component 

geophones and fixed accelerometers.

Two studies, one each in May and June 2014, were 

carried out in two navigable waterway locations—the 

downstream approach channel of the Brandon Road Lock 

and Dam near Joliet, Illinois, and a segment of the Chicago 

Sanitary and Ship Canal near Lemont, Illinois. A limit of 

5 pounds per square inch (5 lb/in2) dynamic underwater 

pressure variation was established based on previous fish 

studies. A limit of 0.75 inches per second (in/s) surface 

ground velocity also was established to preserve the structural 

integrity of the canal walls.

The purpose of the May 2014 study at Brandon Road 

was to understand the magnitude and extent of the pressure 

field created by 80-cubic-inch (in3) water guns in the 

concrete-walled channel downstream of the lock. Additionally, 

parameters of the water guns (distance to canal wall and 

pressure) were changed to understand the effects on wall 

velocity. A single 80-in3 gun produced a roughly cylindrical 

pressure field with a maximum extent of 20 feet (ft) for the 

5 lb/in2 threshold pressure, with a water gun input pressure 

of 700 lb/in2 at a depth of 6 ft below water surface (bws). 

Pressures generally increased with depth, but the size of the 

5-lb/in2

 threshold area decreased above and below the water 

gun depth, extending to less than 15 ft at the water surface. 

The addition of a second 80-in3 water gun, placed directly 

adjacent to the first water gun positioned at 6 ft bws and 

orthogonally to that gun at a depth of 8 ft bws, increased the 

maximum extent of the 5-lb/in2 threshold pressure to 30 ft. 

Neither of the water gun configurations exceeded the given 

threshold of 5 lb/in2 above the static pressure along the walls 

of the canal at the 700-lb/in2 water gun input pressure.

The maximum recorded velocity of pressure waves from 

water guns fired at Brandon Road was 0.239 in/s—less than 

the 0.75 in/s sensitive machinery limit. Velocity data collected 

at the water surface near the wall of the channel showed 

changes relative to water gun input pressure and the number 

of water guns. Velocity data also showed a greater response in 

the vertical component relative to the horizontal component. 

Velocity data collected near the wall of the channel showed 

little change with respect to water gun depth, orientation, and 

distance from the wall. Maximum acceleration values were 

0.0188 ft/s2

 in the upward direction.

In the June 2014 study at Lemont, data were collected 

to further define and increase the resolution of data collected 

in the 2011 study to evaluate the response of the canal wall to 

80-in3 water guns. Water pressures were mapped in a larger 

and more defined areal and depth pattern than in the previous 

2011 study. The extent, shape, and magnitude of the pressure 

fields recorded at Lemont differed in comparison to data 

collected previously at Brandon Road. The pressure field 

varied substantially with respect to water gun input pressure. 

Coverage of the 5-lb/in2 pressure threshold was consistent over 

nearly the entire measured area using a 2,000-lb/in2 gun input 

pressure at 40 ft, whereas minimal coverage of the 5-lb/in2

threshold pressure over the measured area was obtained using 

a 1,000-lb/in2 gun input pressure at 40 ft. Although the Lemont 

pressure data followed trends similar to those at Brandon Road 

(in showing an increase in pressure with depth), the size and 

shape of the pressure field data at Lemont differed (maximum 

extent of the pressure field for a single gun did not occur at the 

gun depth).

The maximum recorded velocity of pressure waves 

from water guns fired at Lemont was 0.304 in/s—less than 

the 0.75 in/s sensitive machinery limit. Velocity data showed 

changes in water gun depth and distance from the wall. 

Velocity data near the canal wall did not vary greatly with 

water gun input pressure and number of water guns. Maximum 

acceleration values were 0.15 ft/s2 both in the upward direction 

and out of the canal wall.

Although water gun input pressures, water gun depth, and 

water gun orientation varied between the testing locations, the 

underwater pressure results suggest that, where possible, water 

guns placed at a set distance from each other are more efficient 

at transmitting pressure at distance in the water than water 

guns placed adjacent to each other.

Acknowledgments

The authors acknowledge the field crews from the 

U.S. Geological Survey Illinois-Iowa Water Science Center 

and Upper Midwest Environmental Sciences Center, and 

Northern Illinois University for collecting the data that made 

this report possible. 
References Cited 55

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Publishing support provided by the U.S. Geological Survey

Science Publishing Network, Tacoma Publishing Service Center

For more information concerning the research in this report, contact the

Director, Illinois Water Science Center

U.S. Geological Survey

405 N Goodwin 

Urbana, IL 61801

https://il.water.usgs.gov
ISSN 2328-0328 (online)

https://doi.org/10.3133/sir20175153

–Adams and others—Water Pressure and Ground Vibrations Induced by Water Guns near Brandon Road Lock and Dam and Lemont, Illinois—Scientific Investigations Report 2017–5153