ERDC/CHL TR-20-12 

Investigation of Shoaling in the Federal 

Navigation Channel, Waukegan Harbor, Illinois 

Coastal and Hydraulics Laboratory 

Zeki Demirbilek, Lihwa Lin, John A. Wethington, Mike Nguyen, 

David F. Bucaro, Monica Ott, Philip Horstman, Joel L. Schmidt, 

Alex R. Hoxsie, Steven R. Goodpaster, Witold Kluza, and 

Ethan J. Theuerkauf

July 2020

Approved for public release; distribution is unlimited.
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 ERDC/CHL TR-20-12 

July 2020 

Investigation of Shoaling in the Federal 

Navigation Channel, Waukegan Harbor, Illinois

Zeki Demirbilek and Lihwa Lin

Coastal and Hydraulics Laboratory

U.S. Army Engineer Research and Development Center

3909 Halls Ferry Road

Vicksburg, MS 39180-6199

John A. Wethington, Mike Nguyen, David F. Bucaro, Monica Ott, Philip Horstman, 

Joel L. Schmidt, Alex R. Hoxsie, Steven R. Goodpaster, and Witold Kluza

U.S. Army Corps of Engineers, Chicago District

231 S. LaSalle Street, Suite 1500

Chicago, IL 60604

Ethan J. Theuerkauf

Michigan State University

East Lansing, Michigan 48824

Final report

Approved for public release; distribution is unlimited. 

Prepared for U.S. Army Corps of Engineers, Chicago District

231 S. LaSalle Street, Suite 1500, Chicago, IL 60604

Under Chicago District, USACE; Program Element No. 280H46
ERDC/CHL TR-20-12 ii

Abstract

Persistent and excessive shoaling occurs in the Outer Harbor and 

Approach Channel of the Waukegan Harbor, Illinois. This report describes 

a numerical modeling study performed for the US Army Corps of 

Engineers, Chicago District, to evaluate the existing harbor and 11

structural alternatives for three crest elevations. This report provides 

details of numerical modeling study, analysis of field data, and estimates 

of shoaling. The focus of the study is the investigation of a variety of 

structural solutions intercepting and/or diverting sediments to reduce 

shoaling in the navigation channel. These include breakwaters, groins, 

spurs, and structural extensions with varying length and crest elevation 

connecting to the north beach and existing north breakwater. Estimates of 

both shoaling volume and height are developed with and without project 

using an integrated wave-flow-sediment transport numerical modeling 

approach. Quantitative reduction estimates are provided for each 

structural alternative investigated.

DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. 

Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. 

All product names and trademarks cited are the property of their respective owners. The findings of this report are not to 

be construed as an official Department of the Army position unless so designated by other authorized documents.

DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR.
ERDC/CHL TR-20-12 iii

Contents

Abstract.................................................................................................................................... ii

Figures and Tables...................................................................................................................v

Preface...................................................................................................................................viii

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

1.1 Background........................................................................................................1

1.1.1 Location of study area ................................................................................................ 1

1.1.2 History of site............................................................................................................... 2

1.1.3 Project description ...................................................................................................... 2

1.1.4 Channel shoaling ........................................................................................................ 4

1.1.5 Expected benefits of modifications............................................................................ 5

1.2 Objectives...........................................................................................................8

1.3 Approach ............................................................................................................8

1.3.1 Modeling approach...................................................................................................10

1.3.2 Modeling tools...........................................................................................................10

1.3.3 Study tasks................................................................................................................ 11

2 Data for the Study ..........................................................................................................14

2.1 Topography, bathymetry, and coastline data .................................................14

2.2 Water level data.............................................................................................. 18

2.3 Wind and wave data....................................................................................... 22

2.4 Sediment data .................................................................................................24

3 Alternatives Investigated ..............................................................................................26

3.1 Alternatives considered.................................................................................. 26

3.2 Description of alternatives..............................................................................27

4 Coastal Modeling System (CMS) Modeling................................................................37

4.1 Description of model .......................................................................................37

4.2 Model grid ....................................................................................................... 38

4.3 Model settings ................................................................................................ 39

4.4 Model calibration and validation................................................................... 42

5 Results and Discussion .................................................................................................50

5.1 Description of simulations ............................................................................. 50

5.2 Phase 1 study shoaling estimates for Waukegan Harbor............................ 50

5.3 Phase 2 study shoaling estimates for three crest elevations...................... 55

5.4 Cost estimates for high- and mid-crest structures ....................................... 63

6 Summary and Conclusions ...........................................................................................65

References.............................................................................................................................68
ERDC/CHL TR-20-12 iv

Appendix: Description of the CMS......................................................................................70

Unit Conversion Factors.......................................................................................................73

Acronyms and Abbreviations...............................................................................................74

Report Documentation Page
ERDC/CHL TR-20-12 v

Figures and Tables

Figures

Figure 1-1. Location of Waukegan Harbor..................................................................................1

Figure 1-2. A sketch of Inner Harbor, Outer Harbor, Approach Channel, and 

Advanced Maintenance Area of Waukegan Harbor..................................................................2

Figure 1-3. Three initial LRC alternatives (Alt 1, Alt 2, and Alt 3). ...........................................6

Figure 1-4. Recent sedimentation pattern in the Approach Channel and Outer 

Harbor..............................................................................................................................................8

Figure 2-1. Lidar coverage polygons from 2007 (yellow), 2008 (red) and 

2012 (white).................................................................................................................................14

Figure 2-2. Contours of Lidar 2008–2012 data (regional)....................................................15

Figure 2-3. Contours of Lidar 2007–2012 data (local zoom). ..............................................15

Figure 2-4. Contour map of combined Lidar 2007–2008–2012 and 

GEODAS datasets. .......................................................................................................................16

Figure 2-5. Details of topography and bathymetry at vicinity of approach channel 

and outer harbor. .........................................................................................................................17

Figure 2-6. Dredged Approach Channel at 7.6 m (25 ft) authorized depth.........................17

Figure 2-7. Location map of NOAA coastal stations................................................................18

Figure 2-8. Water level time series at Milwaukee for 2015...................................................19

Figure 2-9. Location map of ISGS gauges G1, G2(a), and G2(b)..........................................20

Figure 2-10. NOAA 9087057 and ISGS G1/G2 water levels, July–October 2018. ............21

Figure 2-11. Atmospheric pressure from NOAA 9087044 and 9087031...........................21

Figure 2-12. Wind wave data from NDBC 45007, 45174 and GLCFS, March–

November 2015...........................................................................................................................23

Figure 2-13. Hourly wind data from NOAA Stations CHII2 and WHRI2, March–

November 2015...........................................................................................................................24

Figure 2-14. ISGS grab sample location map..........................................................................25

Figure 3-1. A sketch illustrating three general solutions for Waukegan Harbor 

shoaling problem. ........................................................................................................................27

Figure 3-2. Map of the location and shape of structural alternatives..................................29

Figure 3-3. The existing harbor approach channel bathymetry (Alt 0). ................................30

Figure 3-4. A 305 m (1000 ft) groin structure at the North Beach (Alt 1). ..........................30

Figure 3-5. A 244 m (800 ft) long groin attached to the North Beach (Alt 1a). ..................31

Figure 3-6. A 152 m (500 ft) angled spur attached to the Outer Breakwater (Alt 

2)....................................................................................................................................................32

Figure 3-7. A 152 m (500 ft) straight spur attached to the Outer Breakwater (Alt 

2a)..................................................................................................................................................32

Figure 3-8. A 182 m (600 ft) angled spur attached to the Outer Breakwater (Alt 

2b)..................................................................................................................................................33
ERDC/CHL TR-20-12 vi

Figure 3-9. A 305 m (1000 ft) dogleg spur attached to the Outer Breakwater (Alt

2c)..................................................................................................................................................33

Figure 3-10. A 305 m (1000 ft) straight spur attached to the Outer Breakwater 

(Alt 2d)...........................................................................................................................................34

Figure 3-11. A 230 m (750 ft) eastward extension of the Outer Breakwater (Alt 

3)....................................................................................................................................................35

Figure 3-12. A 152 m (500 ft) eastward extension of the Outer Breakwater (Alt 

4)....................................................................................................................................................35

Figure 3-13. A 305 m (1000 ft) eastward extension of the Outer Breakwater (Alt 

5)....................................................................................................................................................36

Figure 3-14. A 305 m (1000 ft) straight groin located north of the Power Plant 

(Alt 6). ............................................................................................................................................36

Figure 4-1. Final numerical model grid domain used in CMS simulations..........................38

Figure 4-2. Details of final CMS grid around vicinity of Waukegan Harbor.........................39

Figure 4-3. Wave height and current vector fields (29 March 2015 @ 2100 GMT)..........41

Figure 4-4. Wave height and current vector fields (9 April 2015 @ 000 GMT). .................41

Figure 4-5. Wave height and current vector fields (31 May 2015 @ 0600 GMT)..............42

Figure 4-6. Model wave results versus data at Buoy 45186 for 20–31 July 2018............43

Figure 4-7. Model wave results versus data at ISGS G1 for 20–31 July 2018. ..................44

Figure 4-8. Model wave results versus data at ISGS G2 for 20–31 July 2018...................44

Figure 4-9. Model wave results versus data at Buoy 45186 for August 2018. ..................45

Figure 4-10. Model wave results versus data at ISGS G1 for August 2018........................45

Figure 4-11. Model wave results versus data at ISGS G2 for August 2018........................46

Figure 4-12. Model waves versus data at Buoy 45186 for September 2018. ...................47

Figure 4-13. Model waves versus data at ISGS G1 for September 2018. ..........................47

Figure 4-14. Model waves versus data at ISGS G2 for September 2018............................48

Figure 4-15. Model waves versus data at Buoy 45186 for 1–20 October 2018. ..............48

Figure 4-16. Model waves versus data at ISGS G1 for 1--20 October 2018.......................49

Figure 4-17. Model waves versus data at ISGS G2 for 1–20 October 2018.......................49

Figure 5-1. Three polygons used to define shoaling areas at Waukegan Harbor...............51

Figure 5-2. Morphology change for Alt1, Alt1a, Alt2, and Alt6 (March–November 

2015).............................................................................................................................................52

Figure 5-3. Morphology change for Alt2a, Alt2b, Alt2c, and Alt2d (March–

November 2015)..........................................................................................................................53

Figure 5-4. Morphology change for Alt0, Alt3, Alt4, and Alt5 (March–November 

2015).............................................................................................................................................53

Figure 5-5. Percent reduction of shoaling in Area 2 and Area 3...........................................55

Figure 5-6. Sub-polygons for detailed analysis of morphology change................................59

Figure 5-7. Location map of sand accumulation for high-crest structures..........................62

Figure 5-8. Location map of sand accumulation for mid-crest structures. .........................62

Figure 5-9. Location map of sand accumulation for low-crest structures. ..........................63
ERDC/CHL TR-20-12 vii

Figure A-1. The CMS framework and its components. ...........................................................70

Tables

Table 1-1. Dredging volumes at Waukegan Harbor (1977–2015).........................................4

Table 2-1. ISGS water level gauge locations and data duration in Waukegan 

Harbor............................................................................................................................................20

Table 2-2. NDBC Station locations and available wind/wave data.......................................22

Table 2-3. ISGS grab sample location, sediment content, and median grain size.............24

Table 3-1. List of twelve alternatives.........................................................................................28

Table 5-1. Morphology change for all alternatives (March–November 2015). ...................54

Table 5-2. The shoaling estimates over a 7-month time (March–September 

2015).............................................................................................................................................57

Table 5-3. The shoaling estimates over a 9-month time (March–November 2015)..........58

Table 5-4. Results for high-crest elevation structures (March–November 2015). .............60

Table 5-5. Results for mid-crest elevation structures (March–November 2015). ..............60

Table 5-6. Results for low-crest elevation structures (March–November 2015)................61

Table 5-7. Cost estimate for alternatives with a high-crest elevation structure...................64

Table 5-8. Cost estimate for Alt 2c and Alt 2d with a mid-crest elevation structure...........64
ERDC/CHL TR-20-12 viii

Preface

This study was conducted for the US Army Corps of Engineers (USACE),

Chicago District (LRC), Program Element No. 280H46, and performed by 

the Coastal and Hydraulics Laboratory (CHL) of the US Army Engineer 

Research and Development Center (ERDC).

At the time the study was completed, Mr. Eddie Wiggins was the Technical 

Director of the Navigation Program. The general administrative 

supervision was provided by Mr. James Gutshall, Chief, Harbors, 

Entrances, and Structures Branch, and Dr. Jacqueline Pettway, Chief, 

Navigation Division.

At the time of publication of this report, Mr. Jeffrey R. Eckstein was the 

Deputy Director of CHL, and Dr. Ty V. Wamsley was the Director.

COL Teresa A. Schlosser was Commander of ERDC, and the Director was 

Dr. David W. Pittman.
ERDC/CHL TR-20-12 1

1 Introduction

1.1 Background

1.1.1 Location of study area

Waukegan Harbor, Illinois, is located in Waukegan, Illinois, in Northern 

Lake County on the western shore of Lake Michigan approximately 64 km*

(40 miles) north of Chicago, Illinois, and 16 km (10 miles) south of the 

Illinois-Wisconsin state line. The harbor is approximately 8 km (5 miles)

south of Illinois Beach State Park and is used for industrial and 

recreational activities. It is a federal navigation project maintained by the 

US Army Corps of Engineers (USACE), Chicago District (LRC). Figure 1-1 

shows the location of study area on a map.

Figure 1-1. Location of Waukegan Harbor. 

 

* For a full list of the spelled-out forms of the units of measure used in this document, please refer to US 

Government Publishing Office Style Manual, 31st ed. (Washington, DC: US Government Publishing 

Office 2016), 248-52, https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPOSTYLEMANUAL-2016.pdf.
ERDC/CHL TR-20-12 2

1.1.2 History of site

The US Congress authorized a navigation project for Waukegan Harbor in 

the Rivers and Harbors Act of 1880 and modified it later through the 

Rivers and Harbors Acts of 1882, 1902, 1930, 1945, 1965, and 1970. The 

Waukegan Harbor site development by the USACE started with 

construction of a breakwater in 1852, and a dredged channel, a basin, and

a harbor with pile piers were added in 1880. Substantial improvements 

made in 1902 included construction of an outer breakwater, a shore 

connection structure, entrance piers, and inner harbor revetment. After 

widening and deepening of the harbor and approach channel between 

1945 and 1965, the present configuration of harbor and navigation channel 

have not changed since 1966. 

1.1.3 Project description

Figure 1-2 shows four key parts of this harbor: “Inner Harbor,” “Outer 

Harbor,” “Approach Channel,” and “Advanced Maintenance Area.” These 

are designated by polygons that show approximate coverage area of each. 

Figure 1-2. A sketch of Inner Harbor, Outer Harbor, Approach Channel, and Advanced 

Maintenance Area of Waukegan Harbor. 

Three structures are present in the existing Waukegan Harbor (Figure 

1-2). These include two parallel entrance jetties that form a narrow 

entrance to the interior of harbor. This Inner Harbor section represents 
ERDC/CHL TR-20-12 3

the innermost basin of the Waukegan Harbor with a narrow navigation 

channel protected by two parallel entrance jetties. The Inner Harbor is 

approximately 915 m (3,000 ft) long, and its narrow channel width ranges

from 55 m (180 ft) to 113 m (370 ft). Approximate lengths of the north and 

south entrance jetties and outer breakwater are 325 m (1,000 ft), 983 m 

(3,225 ft), and 580 m (1,900 ft), respectively. The Inner Harbor requires 

little dredging maintenance because it is sheltered from the effects of 

waves, currents, and sediments. The navigation channel depth in the Inner 

Harbor is 5.5 m (18 ft) and transitions to 6.7 m (22 ft) in the Outer Harbor

and Approach Channel. The outer breakwater was designed to the north of 

entrance to protect the Outer Harbor and Approach Channel. All depths in 

this report are referenced to the Lake Michigan low water datum (LWD)

(LWD = 176.02 m [577.5 ft]) based on the International Great Lakes 

Datum of 1985 (IGLD 85). 

The Outer Harbor in Figure 1-2 refers to the area outside of the parallel 

entrance jetties of the inner harbor. The width of the maintained 

navigation channel in the Outer Harbor increases from 55 m (180 ft) to 

137 m (450 ft). The Outer Harbor is approximately 320 m (1,050 ft) long 

and protected by an outer breakwater, also known as the North 

Breakwater (NB), to the north. The Outer Harbor connects to the 

Approach Channel west of the NB, and part of the Approach Channel 

extends beyond the NB, terminating in Lake Michigan. The Approach 

Channel is approximately 550 m (1,800 ft) long. It has a uniform channel 

width that varies from 137 m (450 ft) to 152 m (500 ft). The Advanced 

Maintenance Area is located north of the Approach Channel and east of 

the NB. The Advanced Maintenance area is part of the Waukegan Harbor 

O&M (Operations & Maintenance) plan by LRC. 

For Waukegan Harbor to be an economically viable commercial port, it 

needs periodic maintenance dredging to maintain authorized depths for 

commercial shipping. Tonnage levels at Waukegan Harbor were relatively 

steady prior to 2008. However, a significant reduction in tonnage starting 

in 2010 was attributed to (1) changes in shipping patterns in Lake 

Michigan and (2) increased shoaling in the Approach Channel and Outer 

Harbor. Waukegan Harbor has been closed to shipping in recent years due 

to the Approach Channel being blocked by shoals emerging during storms. 

Because vessels at Waukegan Harbor were unable to load to their optimal 

drafts, these closures forced tonnages to be diverted to other harbors or to 

use of different transportation modes. These unplanned closures increased 
ERDC/CHL TR-20-12 4

the number of vessel trips and therefore the cost and risk of shipping as 

well. If the chronic shoaling in the Approach Channel is not addressed, the 

present tonnages at Waukegan Harbor will continue to decrease, and 

remaining tonnage will have to be diverted to more costly waterways or 

land routes. This is the primary motivation for LRC to initiate the present 

numerical modeling study to investigate potential causes (environmental 

forcings) and remedies (structural measures) at Waukegan Harbor as part 

of a broader Section 107 navigation study. 

1.1.4 Channel shoaling 

Figure 1-2 shows the existing Waukegan Harbor has a direct exposure to 

waves and currents of Lake Michigan. Wind-generated waves affect this 

harbor from the north to south (180 deg) sector of the lake. Sedimentation 

from north, northeast, east, southeast, and south directions contribute to 

the channel shoaling. The combination of large waves and strong currents

can mobilize excessive sediment volumes, disrupting navigation and port 

operations. Dredging records from 1977 to 2015 (Table 1-1) indicate a 

persistent infilling of the approach channel that increases the annual 

maintenance dredging requirements at Waukegan Harbor. The average 

annual dredging is approximately 30,600 m3/yr (40,000 cy/yr).

Table 1-1. Dredging volumes at Waukegan Harbor (1977–2015). 

Year Volume (cy) Year Volume (cy) Year Volume (cy) 

2015 125,998 2002 48,623 1991 79,482

2013 63,000 2001 56,194 1990 49,513

2012 107,703 2000 56,275 1988 100,996

2011 4,000 1999 61,675 1985 26,180

2010 60,890 1998 40,000 1984 81,000

2009 67,820 1997 29,000 1982 85,396

2008 71,790 1996 53,515 1977 130,000

2005 30,142 1994 44,879

2003 30,712 1993 66,597

Cumulative Volume, cy 

(1977-2015) 1,571,000

Average Annual Dredging, 

cy/yr (1977-2015) 41,000

Average Annual Dredging, 

cy/yr (2008-2015) 71,000
ERDC/CHL TR-20-12 5

A recent historical sediment budget and shoreline evolution study of 

Waukegan Harbor (Morang et al. 2019) reported that the fillet beach to the 

north has migrated lakeward by approximately 305 m (1,000 ft) since the 

1950s. The migration stopped in the last 10 years because the fillet beach 

has no storage capacity remaining. Consequently, sediments can move 

easily into the Advanced Maintenance Area, Approach Channel, and Outer 

Harbor. There are no physical barriers to intercept, divert, or stop sand 

transported by waves and currents into these areas. Insufficient and 

unmaintained depths in the approach channel due to channel infilling do 

not allow for normal levels of waterborne commerce, increasing the

navigation risk and limiting the utilization of Waukegan Harbor.

1.1.5 Expected benefits of modifications

Shoaling in the Approach Channel and Outer Harbor has significantly 

increased over the past decade, impacting the harbor’s ability to reliably 

provide sufficient depths for commercial navigation. The chronic shoaling 

has been persistent and excessive in recent years and caused a significant 

reduction in commercial navigation, requiring periodic dredging of these 

two areas for safe navigation. This has hindered the harbor's reliability for 

commercial navigation and significantly reduced its use. Increased 

shoaling now requires more dredging volumes to maintain the channel for 

a safe navigation. Consequently, properly designed structural 

modifications (alternatives) are in consideration for this Section 107 

navigation project to improve safety and sustainability of commercial 

navigation that can provide significant long-term cost savings. Effective 

sediment trapping by appropriately positioned structures is expected to 

increase reliability of channel depths to allow sustained navigation at 

Waukegan Harbor. 

The types of modifications should involve fewer unknowns and challenges

such as the use of rubble-mound extensions to the existing north

breakwater. Rubble-mound breakwaters have been implemented 

successfully by USACE at many other harbors in Great Lakes. Carefully 

designed extensions to the outer breakwater can be especially beneficial 

for safe and efficient passage of vessels accessing the harbor. The proposed 

modifications need to address both present and future expected commerce 

needs of Waukegan Harbor. A process-based evaluation of structural 

modifications requires a combined wave and circulation modeling system 

with morphodynamics and sediment transport. The modeling domain 

should include the adjacent north and south beaches and surrounding lake 
ERDC/CHL TR-20-12 6

areas to east, north, and south of Waukegan Harbor. This will ensure 

interactions between the harbor, and its surroundings are considered to 

assess safe passage of vessels moving through the Approach Channel and 

Outer Harbor to access the Inner Harbor. 

LRC has considered three modifications to mitigate the shoaling problem 

in the Approach Channel and Outer Harbor. Figure 1-3 shows the shapes 

and locations of three structures proposed by LRC, which are designated 

as Alt 1, Alt 2, and Alt 3. The Alt 1 involves excavation of the updrift fillet 

beach. Alt 2 is a structural breakwater modification for increasing 

sediment trapping capacity. Alt 3 requires installation of an updrift

perpendicular groin sediment trap offsite to the north of the north beach. 

While these alternatives trap littoral sediments affecting the harbor, a 

future maintenance-dredging plan is required to ensure their long-term 

sediment trapping effectiveness. In addition to these three alternatives, 

several other modifications were investigated in the present study. 

Chapter 3 provides details of all structures evaluated in this study.

Figure 1-3. Three initial LRC alternatives (Alt 1, Alt 2, and Alt 3). 
ERDC/CHL TR-20-12 7

The sediment accumulation pattern of sands encroaching into the Approach 

Channel and Outer Harbor from north becomes an important consideration 

for selecting effective modifications. A survey in March 2012 (Figure 1-4) 

suggests that neither far-field solutions (e.g., Alt 1 and Alt 3) nor using a 

short structural modification (e.g., Alt 2) can prevent or alleviate the chronic 

shoaling occurring in the Approach Channel and Out Harbor. For this 

reason, the present modeling study was focused on near-field solutions that 

offer the greatest protection to the impacted areas. The near-field solutions 

include sufficiently long groins, breakwaters, jetties, or spurs. These 

measures providing maximum protection to the Approach Channel and 

Outer Harbor are necessary to improve effectiveness of near-field structural 

modifications. 

The preferred location of such modifications becomes an important 

consideration, the closer to the Approach Channel and Outer Harbor, the 

better. Ideally, a protection situated along the north edge of Approach 

Channel would be the best. These modification structures must extend 

eastward sufficiently into the lake to be effective. The dimensions, cost, 

and constructability of structures will ultimately determine which types of 

structural extension are affordable and viable solutions. A proposed nearfield solution has to provide adequate protection to affected areas by 

essentially sheltering them from the effects of waves, currents, and 

sediments. If appropriately positioned, sediment-intercepting structures 

can effectively block or redirect littoral transport into the Approach 

Channel and Outer Harbor. Protection structures must redirect or bypass 

sediments presently reaching the Waukegan Harbor entrance area.
ERDC/CHL TR-20-12 8

Figure 1-4. Recent sedimentation pattern in the Approach Channel and Outer Harbor. 

1.2 Objectives 

• Evaluate alternatives to improve navigation in the Approach Channel 

and Outer Harbor of Waukegan Harbor. 

• Investigate the efficacy of proposed solutions to increase harbor 

utilization by reducing shoaling in the Approach Channel and Outer 

Harbor. 

• Provide estimates of waves, currents, water levels, morphology change 

for planning, design, operation and maintenance needs at Waukegan 

Harbor, and determine change relative to the existing harbor 

configuration (Alt 0). 

1.3 Approach

A reconnaissance-level evaluation of potential alternatives was conducted 

by LRC in 2017. It was part of a Section 107 investigation at Waukegan 

Harbor for the Federal Interest Determination (FID) study. The FID 

recommended a refined coastal analysis to determine effectiveness of 

potential solutions capable of reducing shoaling in the channel.

Federal navigation designation areas in Waukegan Harbor are marked on 

Figure 1-2. These are the Inner Harbor, Outer Harbor, Approach Channel,

and Advanced Maintenance Area. LRC sought the ERDC expertise to 
ERDC/CHL TR-20-12 9

identify the type of tools and analysis methods required for a comprehensive investigation of the shoaling problem. 

High wave energy in Lake Michigan can move sediments into the harbor 

entrance area. Large infilling rates in the Approach Channel in recent 

years have significantly increased the volume of Waukegan Harbor

annual maintenance dredging. Prior to 2010, the fillet beach to the north 

of Waukegan Harbor had progressively migrated lakeward. The 

migration appears to have stopped in the last 10 years (Morang et al. 

2019). If the fillet beach has little or no storage capacity remaining, more 

sediments can move into the designated Advanced Maintenance Area, 

Approach Channel, and Outer Harbor. Additional physical barriers can 

intercept, divert, and stop sediment coming into the approach channel 

during storms. Insufficient and unmaintained depths in the channel 

resulting from channel infilling will interrupt the normal use of 

waterborne commerce, greatly increase navigation risk, and severely 

limit the overall utilization of Waukegan Harbor.

A critical assessment of the existing harbor infrastructure modification is

required to address present and future navigation needs of Waukegan 

Harbor. Consequently, the evaluation of modifications by numerical 

modeling should be centered on means of extending the existing 

breakwater for safe and efficient passage of waterborne commerce to/from 

the harbor. This requires a combined wave and circulation modeling with 

sediment transport and morphodynamics of the study area that includes

adjacent beaches and Lake Michigan to the north, east, and south of 

Waukegan Harbor. The modeling will help to evaluate safety of vessels 

passing through the Approach Channel and Outer Harbor to access the 

Inner Harbor. 

The updrift fillet beach to the north of the harbor has reached its maximum 

trapping capacity over the past decade (Figure 1-2). This is partly the reason 

for a significant increase in sediment load entering the Approach Channel. 

The shoaling has reduced sufficient depths for commercial navigation and 

substantially increased annual maintenance dredging requirements, thus 

posing a threat to the long-term sustainability of the Waukegan Harbor as a 

commercial port. LRC requested technical assistance in a feasibility-level 

study to evaluate appropriate measures and benefits that can address longterm shoaling at Waukegan Harbor. An outline of the proposed modeling 

study plan follows. 
ERDC/CHL TR-20-12 10

1.3.1 Modeling approach 

The ERDC Coastal and Hydraulics Laboratory (CHL) proposed a twophase numerical modeling study with the Phase 1 focused on a detailed 

investigation of the two new near-field solutions proposed by CHL (Alt 4 

and Alt 5) for protecting the Approach Channel and Outer Harbor areas 

from the combined effects of waves, currents, and sedimentation. The 

extent of protection was determined in terms of reduction of waves and 

currents and resulting shoaling in the Approach Channel and Outer 

Harbor. Short- and long-term numerical simulations identified the merits 

of proposed modifications for navigation (e.g., available depth for 

commercial vessel traffic) into Waukegan Harbor during normal 

operational conditions and following storm events. Using the latest 

bathymetry, wind, wave, and water level data available, benefits of 

alternatives (modifications) were quantified in terms of extent of changes 

in waves, water levels, and sediment volumes in the Approach Channel 

and Outer Harbor relative to the existing harbor configuration (Alt 0). 

The scope of Phase 2 study was determined based on findings of the Phase 1 

investigation. A total of four alternatives were investigated during Phase 2.

The alternatives were evaluated based on reduction of wave energy and 

sedimentation in the Approach Channel and Outer Harbor. The two-phase 

modeling plan was closely coordinated with the LRC team members. 

1.3.2 Modeling tools 

Hydrodynamics, waves, and sedimentation estimates were developed for 

channel infilling in the Approach Channel and Outer Harbor using the 

Coastal Modeling System (CMS). The CMS has been applied in Great Lakes 

to coastal navigation applications for channels, inlets, bays, and estuaries. 

Details of the CMS and its verification and validation are available in the 

References section of this report (Demirbilek et al. 2015a–d; Demirbilek 

and Rosati 2011). The CMS includes a two-dimensional (2D) wave model 

(CMS-Wave) and flow/sedimentation model (CMS-Flow). Nearshore 

processes affecting access and utilization of this harbor were simulated 

using an analysis of metocean climate for normal conditions and storms.

Morphological changes were determined using fine resolution grids to 

represent features of harbor infrastructure to properly model coastal 

processes. The modeling included wave breaking, dissipation, diffraction, 

reflection, transmission, and overtopping of structures, wave-infrastructure,

and wave-current interactions inside the enclosed harbor complex.
ERDC/CHL TR-20-12 11

1.3.3 Study tasks

The following tasks were used to implement the modeling study plan:

Task 1. Develop lake forcing for Waukegan Harbor (winds, waves, water 

levels). Because the entrance to Waukegan Harbor is exposed to Lake 

Michigan, wind, wave, and water level inputs were included in the CMS. 

The lake wind and wave forcing information is available from the Wave 

Information Studies (http://wis.usace army.mil/). National Data Buoy Center 

(NDBC) database (https://www.ndbc.noaa.gov/), additional sources of National 

Oceanic and Atmospheric Administration (NOAA) coastal wind and water 

level data (https://tidesandcurrents.noaa.gov/), and field data available from other 

government agencies, academic institutes, and local airports in the region.

Task 2. Assemble bathymetry and sediment grain size data for numerical 

model grids. Assemble hydrographic survey data including bathymetry, 

shorelines, sediments, and ancillary data to develop grids for numerical 

models covering details of Waukegan Harbor. Obtain the latest data and 

local hydrographic surveys available for the study site of the Approach 

Channel, Outer Harbor, and Inner Harbor and deepwater bathymetry data 

from the NOAA Digital Elevation Maps (https://www.ngdc.noaa.gov/mgg/ coastal/)

and other sources. Develop CMS grids with variable size cells that cover 

details of the Approach Channel, Outer Harbor, Inner Harbor, 

surrounding land and water boundaries of navigation channel, and the 

rest of the harbor complex. Perform test runs to check the adequacy of 

grids and selection of computational parameters. 

Task 3. Set up of models with a selected subset of hydrodynamic 

conditions for fact-finding about alternatives and as is harbor. Develop 

hydrodynamic input data required for numerical modeling including 

winds, waves, water levels, storms, bathymetry, sediments, and ancillary 

data. Select a set of hydrodynamic conditions for setting up wave and 

hydrodynamic models. Perform the CMS modeling for the existing harbor 

configuration (Alt 0). Use Alt 0 results as the base to compare and evaluate 

relative merits of each alternative, starting with the Alt 4 and Alt 5. 

Perform sensitivity tests for optimal structure geometric dimensions (e.g., 

type, location, length, orientation, and water depth). Make appropriate 

adjustments to alternatives based on modeling study results. 

Task 4. Production runs - modeling sedimentation and morphology 

change in the Approach Channel and Outer Harbor. Calculate water level, 
ERDC/CHL TR-20-12 12

wave, and morphology changes for each alternative with the CMS. The 

Illinois Department of Natural Resources provided the latest bathymetry 

of the project site, collected grab samples, and conducted analysis of grain 

size distribution used in the present study. Simulate wave and flow 

processes from the entrance through the inner harbor including wave 

shoaling, refraction, breaking, diffraction, reflection, runup/overtopping 

protective structures, sediment transport, morphology change, and 

channel infilling rates. Develop estimates of shoaling and sedimentation 

for each alternative relative to the existing harbor. Identify depositional 

and erosional areas in the navigation channel (including the Inner Harbor 

and Outer Harbor) and the impacts of corresponding sedimentation on 

adjacent beaches. Perform short- and long-term (e.g., monthly, seasonal, 

and annual) simulations for channel shoaling to identify potential 

depositional and erosional areas for proposed modifications.

Task 5. Structural design calculations. LRC agreed to perform this task 

upon the completion of modeling using structural design methods 

available in the Coastal Engineering and Eurotop manuals. Wave and 

hydrodynamic information is required for these estimates to determine 

stable stone sizes, damage progression, run-up, and overtopping and 

transmission for structures evaluated. The analysis involves structural 

cross-section calculations, including crest elevation, crest width, side 

slopes, and armor stone sizes. The effects of sea level rise, local soil 

subsidence due to weight of structure, and regional settlement in Lake 

Michigan are also considered in this analysis. The modeling results will 

assist the LRC team to perform its structural design.

Task 6. Modeling study results and documentation. This technical report 

provides details of modeling study and results. It describes elements of the 

modeling study, evaluation (comparison and ranking) of alternatives, and 

recommendations. 

This study is subject to “3x3x3 Smart Planning requirements,” necessitating 

completion of a large amount of modeling work within a 15-month time 

period. The modeling study started in Quarter 1/Fiscal Year 18 (Q1/FY18)

upon receipt of partial funding and was completed in Q4/FY19. The scope of 

study changed and expanded as the study progressed and modeling results 

revealed pros/cons of proposed solutions, and suggested consideration of 

others. This change in strategy resulted in investigation of 12 alternatives 
ERDC/CHL TR-20-12 13

(including the existing harbor) instead of the 5 total alternatives (3 by LRC, 

and Alt 4 and Alt 5 by CHL) alluded to in the aforementioned work plan. 

The layout of this report is as follows: In Chapter 1, the introduction

provides history and background, including description of the problem 

and proposed solutions and summary of a comprehensive modeling study 

plan. Chapter 2 describes data used in the present study. Chapter 3 provides 

description of alternatives investigated. Chapter 4 provides details of CMS 

modeling conducted. Chapter 5 provides results and discussion of modeling 

study. Chapter 6 provides summary and conclusions of the study.
ERDC/CHL TR-20-12 14

2 Data for the Study

2.1 Topography, bathymetry, and coastline data

The bathymetry for the exterior and interior of harbor, channels, 

structures (outer breakwater, jetties, seawalls, etc.), and shorelines was

obtained from different sources, including the bathymetry data for entire 

Lake Michigan from three Lidar data in 2007, 2008, and 2012. Figure 2-1 

shows the Lidar coverage areas from 2007 (land only), 2008 (bathymetry 

data only), and 2012 (bathymetric and land data). Figures 2-2 and 2-3 

show the contour maps of combined land and water of the region and local 

areas around Waukegan Harbor.

Figure 2-1. Lidar coverage polygons from 2007 (yellow), 2008 (red) and 

2012 (white). 
ERDC/CHL TR-20-12 15

Figure 2-2. Contours of Lidar 2008–2012 data (regional). 

Figure 2-3. Contours of Lidar 2007–2012 data (local zoom). 
ERDC/CHL TR-20-12 16

The Illinois State Geological Survey (ISGS) at the University of Illinois at 

Urbana-Champaign has conducted nearshore bathymetry surveys outside 

the harbor in 2017 and 2018 using a single beam echo-sounder system 

Estimated accuracy of the lakebed bathymetry is approximately 3 cm (0.1 

ft). Bathymetry data for the offshore area in the present study was 

extracted from the National Geophysical Data Center (NGDC) Geophysical 

Data System (GEODAS) database (https://www.ngdc.noaa. 

gov/mgg/greatlakes/erie.html). Coastline data were extracted from the NGDC

database (http://www.ngdc.noaa.gov/mgg/ shorelines/) and augmented with 

georeferenced image files downloaded from Google Earth Pro 

(http://earth.google.com). All geospatial datasets were converted to Lake 

Michigan’s LWD of 176.02 m (577.5 ft) 

(https://www.lre.usace.army.mil/Portals/69/docs/GreatLakesInfo/docs/IGLD/BrochureOnTheInternation

alGreatLakesDatum1985.pdf). Figure 2-4 shows the contour map of combined 

Lidar 2007–2008–2012 and GEODAS datasets. Figure 2-5 shows details 

of topography and bathymetry at immediate vicinity of the Approach 

Channel and Outer Harbor based on the combined Lidar 2007–2008–

2012 NGDC dataset. Figure 2-6 shows the dredged Approach Channel at 

authorized depth of 7.6 m (25 ft).

Figure 2-4. Contour map of combined Lidar 2007–2008–2012 and 

GEODAS datasets. 
ERDC/CHL TR-20-12 17

Figure 2-5. Details of topography and bathymetry at vicinity of approach channel and 

outer harbor. 

Figure 2-6. Dredged Approach Channel at 7.6 m (25 ft) authorized depth. 
ERDC/CHL TR-20-12 18

2.2 Water level data

Long-term water level data were available from two close-by NOAA coastal 

stations at Calumet Harbor, IL (Station ID: 9087044 or CMTI2; 41° 43.8' N, 

87° 32.3' W) and Milwaukee, WI (Station 9087057; 43° 0.1' N, 87° 53.2' W) 

and (https://tidesandcurrents.noaa.gov). Figure 2-7 shows the location map of these 

two NOAA coastal stations. Figure 2-8 shows hourly water level data in 

Lake Michigan from NOAA 9087044 and 9087057 for 2015. The lake water 

level is usually higher in summer to fall months due to ice melting and 

precipitation while lower in winter and spring seasons. Fluctuations of 

water level are stronger at Calumet Harbor (9087044) as the wind-induced 

seiching is more significant around the southern end of Lake Michigan.

Figure 2-7. Location map of NOAA coastal stations. 
ERDC/CHL TR-20-12 19

Figure 2-8. Water level time series at Milwaukee for 2015. 

The ISGS installed two nearshore wave and water level gauges, G1 and G2, 

for short-term water level measurements at Waukegan Harbor in various 

duration from November 2017 to October 2018. Figure 2-9 shows the 

locations of the ISGS gauges. Table 2-1 presents the location and data 

duration of ISGS gauges in Waukegan Harbor. Figure 2-10 shows the 

water level data collected at ISGS gauges G1/G2 versus NOAA Station 

9087057 in July to October 2018. The difference in water levels between 

G1/G2 and NOAA 9087057 is caused by variation of atmospheric 

(barometric) pressure over Lake Michigan during the period of water level 

measurements. The water level data from NOAA Station 9087057 were the 

exact surface level measurements while the water level data from G1/G2 

gauges were transferred from under water pressure measurements, which 

were affected by the water surface atmospheric pressure variation. 

The G1/G2 gauges were RBR Compact Tide and Wave Loggers and were 

bottom mounted using a concrete frame and anchors. These pressure

sensors utilize pressure (i.e., water depth) to sample wave height, period, 

and water level. The pressure sensor reported accuracy is ±0.05% full 

scale, and the full scale of this sensor is 0.2 m/0.5 m. This results in a 
ERDC/CHL TR-20-12 20

vertical accuracy of wave and water level measurements of 0.15 m.

Figure 2-11 shows water surface atmospheric pressure data from NOAA 

Station 9087044 at Calumet Harbor in the distant south of Chicago 

Harbor and NOAA station 9087031 at Holland, MI, on the east side coast 

of Lake Michigan (Figure 2-7). The comparison of surface pressure 

indicates a small spatial change between the two stations but significant 

temporal change on a daily basis. The influence of surface pressure on 

G1/G2 measurements for water levels is obviously not linear and difficult 

to remove from the G1/G2 measurements to correct the water surface 

elevation. For the same reason, estimates of wave height and period from 

the G1/G2 measurements are affected by the surface pressure variation.

Table 2-1. ISGS water level gauge locations and data duration in Waukegan Harbor. 

Gauge ID Location Data Duration 

G1 42° 21.81' N, 87° 48.28' W 9 July – 18 October 2018

G2 (a)* 42° 21.64' N, 87° 48.84' W 6 November – 31 December 2017

G2 (b)* 42° 21.76' N, 87° 48.86' W 15 July – 18 October 2018

* G2 was initially installed at Location (a) near the east end of South Breakwater and later reinstalled at 

Location (b) in the embayment by the Recreational Beach.

Figure 2-9. Location map of ISGS gauges G1, G2(a), and G2(b). 
ERDC/CHL TR-20-12 21

Figure 2-10. NOAA 9087057 and ISGS G1/G2 water levels, July–October 2018. 

Figure 2-11. Atmospheric pressure from NOAA 9087044 and 9087031. 
ERDC/CHL TR-20-12 22

2.3 Wind and wave data

Long-term coastal wind and wave data in the study area were available 

from various sources. Field wave measurements were available from 

NDBC Buoys 45007 (South Michigan), 45174 (Wilmette, IL), 45186 

(Waukegan Harbor, IL), and 45187 (Winthrop Harbor, IL). Wind data 

were available from NDBC 45007, 45174, WHRI2 (Waukegan Harbor), 

and CHII2 (Chicago, IL). Figure 2-12 shows the locations of these stations.

Table 2-2 presents the NDBC station location and data type. ISGS G1/G2 

collected short-term wave data for the present study.

Table 2-2. NDBC Station locations and available wind/wave data. 

Station ID Location 

Wind 

Data Wave Data 

45007 42° 40.42' N, 87° 1.57' W x x

45174 42° 8.10' N, 87° 39.30' W x

45186 42° 22.10' N, 87° 47.68' W x

45187 42° 29.45' N, 87° 46.73' W x

CHII2 41° 54.97' N, 87° 34.33' W x

WHRI2 42° 21.63' N, 87° 48.80' W x

Long-term wind wave hindcast information for the Great Lakes is 

available from the USACE Wave Information Studies (WIS) database 

(http://wis.usace.army.mil/). For Lake Michigan, the WIS wind wave database 

covers the years from 1960 to 2014. Long-term wave nowcast information 

for Great Lakes is available from NOAA Great Lakes Coastal Forecasting 

System (GLCFS) (https://www. glerl.noaa.gov/res/glcfs/).

Figure 2-12 shows a sample time series of wind and wave information 

from NDBC Buoys 45007 and 45174 and GLCFS at Waukegan offshore 

(42° 21.6' N, 87° 45.0' W) for March to November 2015. NDBC normally 

retrieves the buoys in the Great Lakes during early December and 

redeploys around April to May to avoid icy conditions during the winter 

months. Figure 2-13 shows the sample time series of wind speed and 

direction from CHII2 (Chicago Harbor) and WHRI2 (Waukegan Harbor) 

for March to November 2015. Winds at CHII2 and WHRI2 are overall 

moderate to strong during the period from March to November. Larger 
ERDC/CHL TR-20-12 23

waves are more likely to occur from September to November than from 

March to August.

Figure 2-12. Wind wave data from NDBC 45007, 45174 and GLCFS, 

 March–November 2015. 
ERDC/CHL TR-20-12 24

Figure 2-13. Hourly wind data from NOAA Stations CHII2 and WHRI2, 

March–November 2015. 

2.4 Sediment data

Sediment properties in and around Waukegan Harbor are available from 

the Waukegan Harbor Dredged Material Management Plan report*. ISGS 

has collected 12 grab samples using a ponar grab sampler along the harbor 

entrance, Outer Harbor, and Approach Channel as shown in Figure 2-14.

Table 2-3 presents the sample location, sediment content, and median grain 

size (D50).

Table 2-3. ISGS grab sample location, sediment content, and median grain size. 

Sample ID Latitude (N) Longitude (W) % sand % silt % clay D50 (mm) 

WH01 42.36119 -87.8208 12.23 80.73 7.04 0.16

WH02 42.36123 -87.81902 27.28 67.93 4.79 0.27

WH03 42.36123 -87.81781 62.07 35.59 2.35 0.17

WH04 42.36127 -87.81699 100 0 0 0.28

WH05 42.36127 -87.81634 92.96 6.88 0.16 0.26

WH06 42.36121 -87.81473 71.93 27.00 1.07 0.17

WH07 42.36116 -87.81275 13.27 83.26 3.47 0.23

WH08 42.36228 -87.81375 90.69 9.31 0 0.16

WH09 42.3624 -87.81537 95.64 4.36 0 0.17

WH10 42.36353 87.81448 99.08 0.92 0 0.23

WH11 42.3625 -87.81167 88.03 11.26 0.71 0.26

WH12 42.36143 -87.81004 97.58 2.42 0 0.22

 

* USACE. 2012. Waukegan Harbor DMMP, Appendix C – Geotechnical Engineering. Chicago District 

(LRC).
ERDC/CHL TR-20-12 25

Figure 2-14. ISGS grab sample location map. 
ERDC/CHL TR-20-12 26

3 Alternatives Investigated

3.1 Alternatives considered

Twelve structural alternatives, including the existing harbor, were 

investigated in this study for reducing shoaling in the Approach Channel of

Waukegan Harbor. The alternatives are divided into two groups based on 

their distance to the approach channel. Those within a 1 km (0.62 miles)

distance of harbor are the near-field alternatives while others are the farfield alternatives. The far-field alternatives were expected to have less 

effect on channel shoaling but could reduce channel shoaling by 

intervening with other far-distance sources that ultimately reach the

harbor entrance. Previous sediment budget analyses and regional 

sediment management studies* (Morang et al. 2019) have concluded that 

the north beach is the largest sediment source supply to Waukegan 

Harbor. Consequently, a main objective of each alternative was to alter or 

reduce contribution of this primary supply source. Figure 3-1 shows 

examples of three potential solutions to minimize shoaling in the approach 

channel. These solutions proposed by LRC included removal or excavation 

of the up-drift fillet beach and construction of structural breakwaters and 

groins as sediment traps.

 

* USACE. 2014. Illinois Beach State Park, Lake County, Illinois, Section 204 Beneficial Use of Dredged 

Material, Detailed Project Report, Regional Sediment Management Plan and Environmental 

Assessment, Chicago District (LRC).
ERDC/CHL TR-20-12 27

Figure 3-1. A sketch illustrating three general 

solutions for Waukegan Harbor shoaling problem. 

3.2 Description of alternatives

Twelve structural alternatives were selected for modeling and evaluation

in this study. Table 3-1 provides a list of alternatives with a brief 

description of each. Figure 3-2 is a sketch that shows location and shape of 

these structures. Each alternative includes a modification to Alt 0 (the

existing harbor without project). Details of alternatives and associated 

modifications are described following Figure 3-2.
ERDC/CHL TR-20-12 28

Table 3-1. List of twelve alternatives. 

Alternative Description 

Alt 0 Existing harbor without project

Alt 1 305 m (1000 ft) groin connected to the North Beach

Alt 1a 244 m (800 ft) groin connected to the North Beach

Alt 2 152 m (500 ft) angled spur connected to the Outer Breakwater

Alt 2a 152 m (500 ft) eastward spur connected to the Outer Breakwater

Alt 2b 183 m (600 ft) angled spur connected to the Outer Breakwater

Alt 2c 305 m (1000 ft) dogleg spur connected to the Outer Breakwater

Alt 2d 305 m (1000 ft) eastward spur connected to the Outer Breakwater

Alt 3 228 m (750 ft) eastward extension to the Outer Breakwater

Alt 4 152 m (500 ft) eastward extension to the Outer Breakwater

Alt 5 305 m (1000 ft) eastward extension to the Outer Breakwater

Alt 6 305 m (1000 ft) groin connected to the NB at the Power Plant

Some of the proposed alternatives were expected to reduce sediment build 

up near the trunk area and along northeast face of the outer breakwater. 

The position and dimensions (length, orientation, and crest height) of each 

alternative determine the extent of sediment accumulating in the 

impoundment area. All structures included in these alternatives are 

assumed to be rubble-mound construction. Figures 3-3 to 3-14 depict 

alternatives Alt 0 to Alt 6 and the associated water depth contours around 

the structure. Some alternatives may require additional maintenance

dredging for a long-term sediment trapping effectiveness.
ERDC/CHL TR-20-12 29

Figure 3-2. Map of the location and shape of structural alternatives. 

Alt 0, the existing harbor configuration, represents the baseline geometry 

without any alternative structure. The shoaling rate in all other 

alternatives is compared and referenced to Alt 0. Figure 3-3 shows the 

Alt 0 configuration covering the vicinity of harbor and entrance channel. 

The authorized depth of the Approach Channel is 7.5 m (25 ft). The 

bathymetry is based on a 2018 survey of the post-dredge channel 

according to the authorized depth.

Alt 1 includes a 305 m (1,000 ft) long straight groin (Figure 3-4), located 

approximately 366 m (1,200 ft) north of outer breakwater, that extends 

eastward from North Beach into Lake Michigan. The water depth at the tip 

of Alt 1 structure is 3.5 m (11.5 ft). The sediment diversion and trapping by 

this structure is expected to reduce sediment build up occurring near the 

trunk and along the northeast face of the Outer Breakwater.
ERDC/CHL TR-20-12 30

Figure 3-3. The existing harbor approach channel bathymetry (Alt 0). 

Figure 3-4. A 305 m (1000 ft) groin structure at the North Beach (Alt 1). 
ERDC/CHL TR-20-12 31

Alt 1a includes a 244 m (800 ft) long straight groin, located approximately 

92 m (300 ft) north of the outer breakwater; it is attached to the north

beach (Figure 3-5). The depth at the tip of Alt 1a groin is 3.3 m (11 ft). 

Figure 3-5. A 244 m (800 ft) long groin attached to the North Beach (Alt 1a). 

Alt 2 includes a 152 m (500 ft) long, angled spur connected to the outer 

breakwater (Figure 3-6). The spur points to northeast at a 40 deg angle.

The depth at the tip of the groin is 3.5 m (11.5 ft). Sediment is likely to be 

trapped in the smaller impoundment area between the spur, trunk of the 

outer breakwater, and the north beach. 

Alt 2a is similar to Alt 2 but reorients the 152 m (500 ft) long spur 

eastward into the lake (Figure 3-7). The Alt 2a groin terminates at 4.5 m 

(15 ft) depth. Alt 2b is similar to Alt 2 but extends the angled spur by 30 m 

(100 ft) to approximately the 4 m (13 ft) depth contour (Figure 3-8).

Alt 2c is similar to Alt 2 but extends the length of the groin eastward by 

152 m (500 ft) into the lake (Figure 3-9). The depth at the tip of this dogleg 

groin is 5 m (16 ft).

Alt 2d is similar to Alt 2a but extends the groin by 152 m (500 ft) for a total 

length of 305 m (1000 ft) into the lake (Figure 3-10). This straight groin 

extends to a water depth of 5.7 m (18.7 ft).
ERDC/CHL TR-20-12 32

Figure 3-6. A 152 m (500 ft) angled spur attached 

to the Outer Breakwater (Alt 2). 

Figure 3-7. A 152 m (500 ft) straight spur attached 

to the Outer Breakwater (Alt 2a). 
ERDC/CHL TR-20-12 33

Figure 3-8. A 182 m (600 ft) angled spur attached 

to the Outer Breakwater (Alt 2b). 

Figure 3-9. A 305 m (1000 ft) dogleg spur attached 

to the Outer Breakwater (Alt 2c). 
ERDC/CHL TR-20-12 34

Figure 3-10. A 305 m (1000 ft) straight spur attached 

to the Outer Breakwater (Alt 2d). 

Alt 3 is a 230 m (750 ft) eastward extension of the outer breakwater. The 

straight extension terminates at 7.5 m water depth (Figure 3-11). 

Alt 4 is a 152 m (500 ft) eastward extension of to the outer breakwater. 

This extension terminates at the 7.4 m water depth (Figure 3-12).

Alt 5 is a 305 m (1000 ft) eastward extension of to the outer breakwater.

This extension terminates at the 7.5 m water depth (Figure 3-13).

Alt 6 is a 305 m (1000 ft) long straight groin located north of the Power 

Plant (Figure 3-4) that terminates at approximately the 3 m water depth.
ERDC/CHL TR-20-12 35

Figure 3-11. A 230 m (750 ft) eastward extension 

of the Outer Breakwater (Alt 3). 

Figure 3-12. A 152 m (500 ft) eastward extension 

 of the Outer Breakwater (Alt 4). 
ERDC/CHL TR-20-12 36

Figure 3-13. A 305 m (1000 ft) eastward extension 

of the Outer Breakwater (Alt 5). 

Figure 3-14. A 305 m (1000 ft) straight groin located north 

of the Power Plant (Alt 6). 
ERDC/CHL TR-20-12 37

4 Coastal Modeling System (CMS) Modeling

4.1 Description of model

This modeling study used an integrated CMS developed for coastal and 

inlet processes in USACE navigation projects 

(http://cirp.usace.army.mil/products/cms.php). The CMS simulates nearshore waves, 

currents, water levels, sediment transport, morphology change, salinity, 

and temperature on desktop computers. It is designed for coastal inlets 

and navigation studies involving channel performance and sediment 

exchange between inlets and adjacent beaches. 

The Surface-water Modeling System (SMS) (www.aquaveo.com/products) interface 

of the CMS is used for grid generation, model setup, and post-processing 

(Demirbilek et al. 2007; Zundel 2006). The CMS Verification and 

Validation (V&V) tests with analytical solutions, idealized examples, and 

laboratory and prototype applications have been documented in four 

technical reports (Demirbilek and Rosati 2011; Lin et al. 2011a,b; Sanchez 

et al. 2011a,b). Additional information about the CMS is available in 

technical notes, journal papers, wiki pages, and from the Coastal Inlets 

Research Program (CIRP) website: http://cirp.usace.army.mil/wiki/CMS; 

https://cirpwiki.info/wiki/CMS/ValidationTestCases; https://cirpwiki.info/wiki/Test_Cases.

Wave-current interactions and variation in water levels affect hydrodynamics and the resulting sediment transport and morphological 

changes at Waukegan Harbor. The CMS consists of a spectral wave model, 

CMS-Wave (Lin and Demirbilek 2012; Lin et al. 2011a,b; Lin et al. 2008; 

Demirbilek et al. 2007) and a shallow-water equations based flow model 

(CMS-Flow) that includes sediment transport and morphodynamic 

calculations. The appendix of this report provides a detailed description of 

the CMS. The References section of this report includes several recent field 

applications of the CMS (e.g., Demirbilek et al. 2018, 2017, 2016a,b; 

2015a,b,c,d).

CMS-Wave is a steady-state 2D spectral wave model (Lin et al. 2008; Lin 

et al. 2011a,b) capable of simulating wave processes including wave

generation and growth with ambient currents at coastal inlets, harbors,

and navigation channels. It uses the wave-action balance equation that 

includes the following wave processes: wave propagation, refraction, 

shoaling, diffraction, reflection, breaking, and dissipation. Deeper water 
ERDC/CHL TR-20-12 38

incident waves in Lake Michigan were transformed to the project site using 

CMS-Wave to develop nearshore wave estimates outside and inside 

Waukegan Harbor. The computational efficiency of CMS-Wave and

recently improved capabilities of the model (Lin and Demirbilek 2012; Lin 

et al. 2011a,b; Demirbilek and Rosati 2011) allowed for simulating a large 

spatial domain and a number of wave conditions in this application. The 

dynamic coupling of CMS-Wave with CMS-Flow and WaveNet/TideNet 

were used in the modeling of nearshore coastal processes. 

4.2 Model grid

Figure 4-1 shows the numerical model domain with bathymetric contours 

superimposed on a Google Maps background image. The CMS modeling 

covers a rectangular area of 6.8 km (easting) × 9.1 km (northing) with 

higher cell resolution of 5 m around the harbor channel and lower 

resolution of 150 m away from the harbor.

Figure 4-1. Final numerical model grid domain used in CMS simulations. 
ERDC/CHL TR-20-12 39

The extent of grid domain and grid resolution affects the run time and 

computing resources (memory and disk space) required. Ultimately, the 

sediment transport and morphology change with a longer simulation 

determined the final modeling grid specifications (e.g., grid dimensions, 

grid resolution, and length of simulation). Figure 4-2 provides a closer 

view of the grid and bathymetry encompassing the Waukegan Harbor 

complex, and details of the topography/bathymetry in the immediate 

vicinity of the Approach Channel and Outer Harbor.

Figure 4-2. Details of final CMS grid around vicinity 

of Waukegan Harbor. 

4.3 Model settings

Available nearshore wind, wave, and water level measurements at and 

near the project site from Milwaukee to Chicago were used in the model.

The wave diffraction intensity was set to 4 (default) for the maximum 

diffraction allowed in CMS-Wave. A constant Darcy-Weisbach coefficient 

of 0.005 and a constant reflection coefficient of 0.3 (default) were applied 

for bottom friction and forward reflection calculations, respectively 

(Demirbilek et al. 2018, 2017, 2015a–d). Incident wave spectra were 

specified with 40 frequency bins (covering the range of 0.06 to 0.45 Hz at 

0.01 Hz increment) and 35 direction bins (covering a half-plane for 

incoming wave direction in the range of 0 to 180 deg azimuth with 5 deg 

increment). Wave runup on breakwaters and infra-gravity wave options 

were activated in simulations.
ERDC/CHL TR-20-12 40

The CMS-Flow explicit-solver version was used in the coupling with CMSWave. A time-varying water level was specified along the CMS-Flow 

offshore boundary. The hydrodynamic time-step is set to 0.25 sec while 

sediment transport and morphology time steps are equal to 2 and 4 sec, 

respectively. The non-equilibrium formulation and a median grain size of 

0.2 mm were used in the model sediment transport and morphology 

change. The bed load and suspended load factors are set to 1.5 and 0.2, 

respectively. For bottom friction, a constant Mannings coefficient of 0.015 

was specified in the model simulation (Demirbilek et al. 2018, 2017, 

2015a–d). 

The model was run on the same grids used in CMS-Wave. The coupled 

CMS-Wave and CMS-Flow simulations used a 3 hr interval. There is a twoway feedback between the wave and flow models using the steering

framework in the SMS. This includes using wave radiation stress fields 

computed from the CMS-Wave as wave forcings to CMS-Flow and using 

the current and water level fields computed from the CMS-Flow as 

feedback to CMS-Wave. The wave radiation stresses from two consecutive 

CMS-Wave runs are linearly applied in the CMS-Flow simulation. 

Wave model results were saved over the entire computational domain. 

These included significant wave height, peak period, and mean direction. 

Model results were saved (e.g., wave parameters and spectra) from CMSWave grid at the points of interest along the north beach and in/around 

the harbor entrance.

Figure 4-3 shows model wave height field in color scaling and current 

vector fields for one southeast (SE) storm event on 29 March 2015 @ 2100 

Greenwich Mean Time (GMT) (Hs = 1.7 m, Tp = 5.7 sec, θwave = 157 deg, 

Uw = 15. 3 m/sec, θwind = 190 deg). Figure 4-4 shows model wave height 

and current fields for a northeast (NE) storm condition on 9 April 2015@ 

0000 GMT (Hs = 1.0 m, Tp = 4.1 sec, θwave = 33 deg, Uw = 8.1 m/sec, 

θwind = 33 deg ). Figure 4-5 shows a severe NE storm occurring on 31 May 

2015 @ 0600 GMT (Hs = 3.5 m, Tp = 7.5 sec, θwave = 23 deg, Uw = 16 

m/sec, θwind = 12 deg). The wind speed ranged from 8 m/sec to 16 m/sec 

in this simulation. Model results indicated waves breaking along the 

shallow depths of north and south beaches. Wave heights at the harbor 

entrance were generally less than 1 m.
ERDC/CHL TR-20-12 41

Figure 4-3. Wave height and current vector fields 

(29 March 2015 @ 2100 GMT). 

Figure 4-4. Wave height and current vector fields 

(9 April 2015 @ 000 GMT). 
ERDC/CHL TR-20-12 42

Figure 4-5. Wave height and current vector fields 

 (31 May 2015 @ 0600 GMT). 

4.4 Model calibration and validation

The calibration and validation of model waves were conducted for July–

August and September–October 2018, respectively. Model forcing 

included offshore incident waves from NOAA Buoy 45187 (Winthrop 

Harbor, IL), local water levels from NOAA Station 9087057 (Milwaukee, 

WI), and surface wind data from WHRI2 (Waukegan Harbor). Model 

channel shoaling rates were compared to survey data for 2015. 

Model waves were compared to the measurements at NDBC Buoy 45186 

(Waukegan Harbor) and ISGS Gauges G1 and G2. Figures 4-6 to 4-8 

show model calibration of wave heights and periods versus data at Buoy 

45186, Gauge G1, and Gauge G2, respectively, for 20-31 July 2018.

Figures 4-9 to 4-11 show model waves versus data at Buoy 45186, Gauge 

G1, and Gauge G2, respectively, for August 2018. For G1 and G2, 

apparent strong surface atmospheric (barometric) pressure disturbance 

has caused high noise in wave measurements. Accordingly, a significant 

amount of wave data in G1 and G2 were affected and removed for 

comparison with model waves. Conversely, model wave results used the 
ERDC/CHL TR-20-12 43

incident wave input from NDBC Buoy 45187, located 10 miles north of 

Waukegan Harbor. The local wind data from NOAA Station WHRI2 used 

as input may also affect model results as the data may not represent the 

over-water winds well for modeling.

Figure 4-6. Model wave results versus data at Buoy 45186 for 20–31 July 2018. 
ERDC/CHL TR-20-12 44

Figure 4-7. Model wave results versus data at ISGS G1 for 20–31 July 2018. 

Figure 4-8. Model wave results versus data at ISGS G2 for 20–31 July 2018. 
ERDC/CHL TR-20-12 45

Figure 4-9. Model wave results versus data at Buoy 45186 for August 2018. 

Figure 4-10. Model wave results versus data at ISGS G1 for August 2018. 
ERDC/CHL TR-20-12 46

Figure 4-11. Model wave results versus data at ISGS G2 for August 2018. 

Figures 4-12 to 4-14 show model verification of wave heights and periods 

versus data at Buoy 45186, Gauge G1, and Gauge G2, respectively, for 

September 2018. Figures 4-15 to 4-17 show model waves versus data at 

Buoy 45186, Gauge G1, and Gauge G2, respectively, for 1–20 October 

2018. A significant portion of wave data at G1 and G2 were removed in the 

comparison with model waves as the data were contaminated by strong 

surface pressure variations that occurred during wave measurements.
ERDC/CHL TR-20-12 47

Figure 4-12. Model waves versus data at Buoy 45186 for September 2018. 

Figure 4-13. Model waves versus data at ISGS G1 for September 2018. 
ERDC/CHL TR-20-12 48

Figure 4-14. Model waves versus data at ISGS G2 for September 2018. 

Figure 4-15. Model waves versus data at Buoy 45186 for 1–20 October 2018. 
ERDC/CHL TR-20-12 49

Figure 4-16. Model waves versus data at ISGS G1 for 1--20 October 2018. 

Figure 4-17. Model waves versus data at ISGS G2 for 1–20 October 2018. 
ERDC/CHL TR-20-12 50

5 Results and Discussion

5.1 Description of simulations

This chapter describes shoaling estimates for each investigated alternative 

based on model-calculated sediment transport and morphology changes.

Numerical simulations were performed for 12 alternatives including the 

existing harbor described in Chapter 3 for a year-long time period. The 

year 2015 was selected as a recent average climate year for 9-month 

(March–November 2015) simulations, excluding ice conditions during 

winter months. These simulations helped to determine the sensitivity of 

shoaling rates occurring during different times of the year.

5.2 Phase 1 study shoaling estimates for Waukegan Harbor

The sediment transport and morphology change is for a 9-month (March–

November 2015) simulation with combined CMS wave and hydrodynamics 

models. Estimates of the shoaling volume and the sediment accumulation 

hotspots were made for three areas of interest:

• Area 1: Inner Harbor (IH)

• Area 2: Outer Harbor (OH) + Approach Channel (AC)

• Area 3: Advance Maintenance (AM) area.

Figure 5-1 shows the boundaries of these areas in the existing harbor 

configuration (Alt 0). Hereafter, these areas are referred to as “Area 1”, 

“Area 2,” and “Area 3.” Area 2 covers only the navigable (dredged) sections 

of the OH and AC. Area 3 included Area 2 and part of the impoundment 

area along the outer breakwater. 
ERDC/CHL TR-20-12 51

Figure 5-1. Three polygons used to define shoaling areas at Waukegan Harbor. 

Figures 5-2, 5-3, and 5-4 show the 2D maps of morphology change for all

alternatives investigated. In these figures, the vertical variation at each 

model grid point represents the morphology change. This change 

represents sediments moved by waves and currents. The channel shoaling, 

denoted by yellow and red, increases if more sediments reach a grid point 

and remain there. Because morphology change is relative to the initial 

depth at a grid point, it represents the time-varying depth change at the 

end of a simulation. Thus, the morphology change is the depth difference 

at any grid point between the start and end times of a simulation. The 

9-month simulation time represents the entire year of 2015 excluding a 

3-month (December, January, and February) period during which the lake 

might have ice. 

Simulations were performed on desktop Windows 10 personal computers

with 16 to 32 GB memory and 12 to 48 processors. The computer run time 

for a 9-month simulation ranged from 17 days to 21 days. The coupled CMSWave and CMS-Flow (explicit model) simulations required the use of a 

steering module available in version 11.0 of the SMS (SMS 11.0). The SMS 
ERDC/CHL TR-20-12 52

was also used for grid generation, pre-/post-processing of model inputs and 

outputs, generating 2D spatial images to show variation of morphology 

change, and generating the tabulated modeling results in this chapter. 

A positive value of the morphology change in these plots denotes sediment 

accretion (deposition) or areas gaining material while a negative value 

signifies erosional areas loosing material. Red and yellow indicate accretion 

areas and blue signifies erosion. The intensity of colors represents severity 

(magnitude) of the morphology change. For each alternative, these 2D 

contour maps display the spatial distribution of sedimentation at the end of 

the 9-month simulation. The morphology change maps are provided for 

three groups, each group with four alternatives: Group 1 (Alt 1, Alt 1a, Alt 2, 

Alt 6) shown in Figure 5-2; Group 2 (Alt 2a, Alt 2b, Alt 2c, Alt 2d) in Figure 

5-3; and Group 3 (Alt 0, Alt 3, Alt 4, Alt 5) in Figure 5-4. Chapter 3 provides 

detailed information about each alternative. The sketch of each alternative 

super-imposed on a 2D map shows its location and geometry (shape). These 

maps also depict locations of the hot spot areas created by each alternative.

Figure 5-2. Morphology change for Alt1, Alt1a, Alt2, and Alt6 

(March–November 2015). 
ERDC/CHL TR-20-12 53

Figure 5-3. Morphology change for Alt2a, Alt2b, Alt2c, and Alt2d 

(March–November 2015). 

Figure 5-4. Morphology change for Alt0, Alt3, Alt4, and Alt5 

(March–November 2015). 
ERDC/CHL TR-20-12 54

Table 5-1 presents the summary of 9-month (March–November 2015) 

morphology change estimates for all alternatives in the three polygon areas 

shown in Figure 5-1. Shoaling volume estimates in Area 1, Area 2, and 

Area 3 are provided in cubic meter (m3) and cubic yards (cy). Existing 

Harbor (Alt 0) serves as the baseline without project condition and is used 

to evaluate effectiveness of other alternatives. Alt 1a, Alt 2b, Alt 2c, and 

Alt 2d are marked in bold in Table 5-1. These were not in Phase 1 study and 

added later as Phase 2 study. All alternatives involved certain modifications 

to the existing harbor in order to reduce chronic channel shoaling.

Table 5-1. Morphology change for all alternatives (March–November 2015). 

Alternatives 

(Groins, spurs and 

brkwtr extensions)

9-Month Morphology Change** (m3) 

Area 1 

(Inner 

Harbor) 

Area 2 

(Outer harbor + 

Approach channel) 

Area 3 

(Area 2 + Advance 

maintenance dredge 

area) 

Alt 0

w/o project (as is)

 130

(170*)

14,000

(18,300)

39,800

(52,000)

Alt 1

1000-ft N groin

 150

(195)

9,100

(11,900)

19,000

(24,850)

Alt 1a*** 

1000 ft S groin 

 140 

 (180) 

 9,800 

 (12,800) 

 20,600 

(26,950) 

Alt 2

500 ft angled spur

 80

(105)

9,050

(11,840)

26,500

(34,660)

Alt 2b*** 

580 ft angled spur 

 130 

 (170) 

 8,000 

 (10,460) 

 24,100 

(31,520) 

Alt 2c*** 

1000 ft dogleg spur 

 144 

 (188) 

 5,700 

 (7,450) 

 19,795 

(25,870) 

Alt 2a

500 ft E-W ext

 140

(180)

9,500

(12,425)

29,800

(38,975)

Alt 2d***

500 ft E-W ext

 141

(184)

4,673

(6,107)

20,933

(27,360)

Alt 3 

750 ft E-W ext

120

(160)

4,300

(5,620)

27,100

(35,420)

Alt 4

500 ft ext

 130

(170)

6,550

(8,560)

29,100

(37,900)

Alt 5

1000 ft ext

 130

(170)

2,650

(3,500)

20,800

(27,200)

Alt 6 1000 ft groin 

@power station

 130

(170)

13,300

(17,400)

38,800

(50,750)

*Quantity shown in parentheses is cubic yard (cy)

**CMS with D50 = 0.2 mm and n = 0.015

***New alternatives
ERDC/CHL TR-20-12 55

Sensitivity tests were performed with different sediment grain sizes and 

Manning’s coefficients to check model results. The sediment grain size of 

D50=0.2 mm and Manning’s coefficient of n=0.015 yielded the best match 

to dredging data. The performance ranking of the 12 alternatives is 

presented in Figure 5-5 based on the data in Table 5-1. Blue and red 

markers represent percent reduction in the shoaling volumes in Area 2 

and Area 3, respectively. Among all alternatives, Alt 5, Alt 3, Alt 2c, and 

Alt 2d performed the best with a percent reduction ranging from 60% to 

85%. Alt 4 with a 55% reduction follows these top performers. Other 

alternatives (Alt 1, Alt 1a, Alt 2, Alt 2a, and Alt 2b) achieved a lower 

percent of reduction from 30% to 40%. Alt 6, a far-field solution located 

near the Waukegan Power Plant produced no reduction and did not affect 

harbor shoaling. Figure 5-5 indicates the distance of an alternative to the 

harbor entrance is one of the controlling factors for effectiveness of sandtrapping structural alternatives.

Figure 5-5. Percent reduction of shoaling in Area 2 and Area 3. 

5.3 Phase 2 study shoaling estimates for three crest elevations

LRC developed cost estimates for the 12 alternatives investigated based on 

modeling results summarized in Table 5-1 for high-crest structural 

elevation of 1.98 m (6.5 ft). Among all alternatives, Alt 5, Alt 3, Alt 2c, and 

Alt 2d were the top four performers (Figure 5-5). This group was selected 
ERDC/CHL TR-20-12 56

for additional investigation in the Phase 2 modeling study with two 

specific objectives in mind: (1) to evaluate the sensitivity of cost estimates 

to the structural crest elevation and (2) to investigate the seasonal 

variation of channel shoaling as a function of the length of simulation.

In the Phase 2 study, three structural crest elevations (high, middle, and 

low) and three simulation lengths (7-month, 2-month, and 9-month) were 

further investigated. The high-crest elevation of 1.98 m (6.5 ft LWD)

corresponds to a vertical datum of 178 m (584 ft) IGLD85 representing a

50-year return period water level for Lake Michigan. The mid-crest

elevation of 0.78 m (2.5 ft LWD) corresponds to 176.8 m (580 ft) IGLD85

and a 20-year design water level for Lake Michigan. The low-crest

elevation of 0 m (0 ft LWD) corresponds to a vertical datum of 176.02 m 

(577.5 ft) IGLD85.

Numerical simulations were performed for three time lengths: 7 month 

(March–September 2015), 2 months (October–November 2015), and 

9 months (March–November 2015). These simulations helped to 

determine the sensitivity of shoaling rates occurring during different 

times of the year. A particular interest was in the 2-month (October–

November 2015) simulation because the largest storms generally 

occurred during these months. Model results indeed confirmed greater 

shoaling volume estimates during these 2 months relative to the first 

7 months (March–September 2015).

Table 5-2 and Table 5-3 present shoaling volume estimates for 7-month 

(March–September 2015) and 9-month (March–November 2015) periods, 

respectively. A continuous 9-month simulation was conducted for 

comparison of combined results from 7-month and 2-month simulations. 

This showed that volume estimates from two consecutive shorter 

simulations might be linearly added to provide an approximate projection 

for a longer timeframe. Such a projection should be verified before it can 

be used in practice. The spatial change in the shoaling height (e.g., the 

height of accretion or erosion) did not follow a linear superposition of 

results from two consecutive shorter simulations. Modeling results 

revealed comparatively greater shoaling occurring in the last 2 months 

(October–November 2015), indicating a correlation between the channel 

shoaling and large storms during these 2 months. 
ERDC/CHL TR-20-12 57

For each alternative listed in Tables 5-2 and 5-3, values in parentheses are 

the percent estimates (e.g., divided by the Alt 0 estimate) expressing the 

estimate as a percentage of the Alt 0 estimate. The total estimates from the 

9-month simulation are not necessarily a linear sum of results from the 

7 month and 2-month simulations.

Table 5-2. The shoaling estimates over a 7-month time (March–September 2015). 

In Tables 5-2 and 5-3, the performance of Alt 3, Alt 5, Alt 2c, and Alt 2d 

has been quantified as a scaled percentage relative to Alt 0 (w/o project 

condition). This metric defines the effectiveness of an alternative. The 

shoaling volume estimates less than 50% are marked in red. The percent 

reduction in shoaling for each alternative is calculated from the scaled 

percentages. Because either volumes or percent reduction estimates can be 

used in engineering practice, both estimates are provided for the three 

structural crest elevations. Although structures with the high-crest 

elevation performed the best, because the construction cost is directly 

proportional to the size of a structure (length, width, height and water 

depth), the mid- and low-crest structures have become of particular 

interest to this project for reducing structural design costs. 
ERDC/CHL TR-20-12 58

Table 5-3. The shoaling estimates over a 9-month time (March–November 2015). 

Tables 5-2 and 5-3 provide an overall summary for four alternatives: Alt 5, 

Alt 3, Alt 2c, and Alt 2d. In addition, a detailed analysis was performed for 

the morphological change in two areas of interest (Area 2 and Area 3).

This required dividing each area into a number of smaller polygons shown 

in Figure 5-6. Area 2 was divided into ten 100 m long sub-polygons. These 

are marked in Figure 5-6 as OH1 to OH3 and AC1 to AC7. Area 3 was 

divided into four sub-polygons marked as AM1 to AM4, where AM1 covers 

the existing advanced maintenance area while AM2, AM3, and AM4 

extend beyond the acreage of Area 3. These extended advanced 

maintenance areas are greater than the original area. Note that the 

estimates for Area 1 (IH) used only one polygon because the amount of 

shoaling in the IH was negligible and did not warrant sub-dividing Area 1 

into sub-polygons. 
ERDC/CHL TR-20-12 59

Figure 5-6. Sub-polygons for detailed analysis of morphology change. 

Tables 5-4, 5-5, and 5-6 provide sediment shoaling volumes (m3) and 

height of the accumulation (m) for Alt 5, Alt 3, Alt 2c, and Alt 2d for high-, 

mid-, and low-crest elevations, respectively. Volume estimates and 

maximum shoaling heights are tabulated in the left and right sides, 

respectively, of these tables. The estimates are provided for each subpolygon within Areas 2 and 3 followed by the total estimate for each area. 

The estimates for Alt 0 (w/o project) are also shown for comparison 

purposes. The high-crest structural elevation produced the lowest total 

sand accumulation volumes in Area 2. The largest volume of 4,722 m3 for 

Alt 2c in AC is less than 33% of Alt 0. This corresponds to a 67% reduction 

in the AC shoaling volume. The maximum shoaling of 0.46 m in Area 2 is 

nearly 30% of the Alt 0 maximum shoaling of 1.25 m. These results clearly 

show the high effectiveness of these four alternatives with high-crest 

elevation for significantly reducing the shoaling in Area 2. 
ERDC/CHL TR-20-12 60

Table 5-4. Results for high-crest elevation structures (March–November 2015). 

Table 5-5. Results for mid-crest elevation structures (March–November 2015). 
ERDC/CHL TR-20-12 61

Table 5-6. Results for low-crest elevation structures (March–November 2015). 

Results for the alternatives with the mid-crest elevation are similar to 

those for the high-crest elevation (e.g., 4,676 m3 vs. 4,722 m3 and 0.47 m 

vs. 0.46m in Area 2). For the low crest elevation, only Alt 2c and Alt 2 

provide limited channel shoaling reduction in Area 2. This detailed 

analysis suggests that the mid-elevation structures, and Alt2c and Alt2 at 

low elevation, can be considered because of their reasonably good 

performance (50% to 75%) relative to the high-crest elevation structures. A 

substantial design cost savings is possible for these mid- or low-crest 

elevation structures, but long-term maintenance cost could be higher. 

Figures 5-7, 5-8, and 5-9 display the pattern of sediment accumulation for 

four alternatives with three structural crest elevations. These figures are 

color coded to highlight the hot spot areas where increased sediment 

accumulation occurs. The hot spot area generally develops adjacent to a 

structure but the presence of a structure can also impact adjacent areas. 
ERDC/CHL TR-20-12 62

Figure 5-7. Location map of sand accumulation for high-crest structures. 

Figure 5-8. Location map of sand accumulation for mid-crest structures. 
ERDC/CHL TR-20-12 63

Figure 5-9. Location map of sand accumulation for low-crest structures. 

5.4 Cost estimates for high- and mid-crest structures

Based on modeling results investigated in Phase 1 and Phase 2 studies, 

LRC developed preliminary cost estimates for alternatives. These 

estimates assumed construction of alternatives structures with 1:2 side 

slopes as rubble-mound breakwaters using 20-ton A-stone size rocks and 

a 3.05 m (10 ft) structural subsidence. The estimates increase/decrease if 

any of these assumptions change or if the geometry of an alternative 

changes. These costs represent physical construction of the breakwater 

only and exclude maintenance of the structure, maintenance dredging 

behind the structure, etc.

Table 5-7 presents the cost estimates for nine alternatives investigated in 

the Phase 1 study. These estimates assumed all alternatives had a high-crest 

elevation (178 m or 584 ft IGLD85 ). Table 5-8 provides estimates for Alt 2c 

and Alt 2d, the top-two performing alternatives in the Phase 2 study with 

mid-crest elevation (176.8 m or 580 ft IGLD85). The cost information 

provided in this report is only for future reference. Note that the two highest 

costs ($57.5 million and $42.4 million) are for Alt 5 and Alt 3 with highcrest elevation structures. The costs for Alt 2d and Alt 2c with mid-crest 

elevation structures are comparatively less ($30 million and $24.3 million). 
ERDC/CHL TR-20-12 64

Table 5-7. Cost estimate for alternatives with a high-crest elevation structure. 

Table 5-8. Cost estimate for Alt 2c and Alt 2d with a mid-crest elevation structure. 
ERDC/CHL TR-20-12 65

6 Summary and Conclusions

This is a detailed numerical modeling study with field data collection 

conducted for Waukegan Harbor. The study was performed to better 

understand the dynamic nature of the harbor-lake system. An expanded 

comprehensive modeling study can produce rational and scientifically 

defensible findings to identify alternatives to increase safety and promote 

sustainable long-term navigability at Waukegan Harbor. The study used 

findings from previous studies*†‡ (Morang et al. 2019) to focus on 

evaluation of a number of alternative structural design options. 

The dynamic lake setting of the study area requires a thorough 

understanding of the local metocean forcings to reduce uncertainties and 

assumptions used in prior studies. The numerical modeling study was 

tasked to investigate sediment trapping and diversion using shoreconnected structural measures. Effectiveness of each modification 

(alternative) for improving navigation at Waukegan Harbor was examined 

to identify potential solutions for significant long-term cost savings 

compared to increased maintenance dredging. The chosen alternatives 

intercepted and diverted sediments affecting access to the harbor, also 

benefiting beaches to the north and south. The selected alternatives are 

compatible with public use of beaches and improve life and public safety, 

recreation, and beach management and regulatory considerations. The 

primary purpose of proposed alternatives is to reduce long-term O&M costs 

of the approach channel, outer harbor, and advanced maintenance areas.

The estimates of morphology change, shoaling volumes, and navigable 

depth changes inside, outside, and around Waukegan Harbor were 

developed using an integrated CMS. A combined (coupled) wave, 

hydrodynamic, and sediment transport modeling was performed to 

develop estimates for 1-year time period. The year of 2015 was selected 

because it was an average climate year for which the entire year 

metocean data (wind, water level, and wave) were available. The 

modeling study first investigated the sediment trapping capability of 

 

* USACE. 2014. Illinois Beach State Park, Lake County, Illinois, Section 204 Beneficial Use of Dredged 

Material, Detailed Project Report, Regional Sediment Management Plan and Environmental 

Assessment, Chicago District (LRC).

† USACE. 2016. Waukegan Harbor, Illinois Continuing Authorities Program, Section 107 Federal Interest 

Determination (FID) Report, Chicago District (LRC).

‡ USACE. 2017. Waukegan 107 Continuing Authorities Program (CAP) Section 107 Project Management 

Plan (PMP), Chicago District (LRC).
ERDC/CHL TR-20-12 66

structures identified by LRC in the Phase 1 study. The study’s scope was 

expanded in the Phase 2 modeling to include additional alternatives. A 

total of 12 alternatives, including the existing harbor, were modeled to 

determine potential effects of various structural factors on channel 

shoaling. These factors influence the efficiency of proposed alternatives 

to reduce harbor shoaling and included the position, orientation, length, 

and crest elevation of structures and water depth. 

The modeling domain covered a rectangular area of 6.8 km (easting) ×

9.1 km (northing) with a 5 m finer cell resolution near the harbor channel 

and 150 m lower resolution away from the harbor. The Lidar data collected 

in 2007, 2008, and 2012 by NGDC were used for the bathymetry and 

shorelines. More recent bathymetric survey data in 2017 by the ISGS 

University of Illinois at Urbana-Champaign were used to update the CMS 

modeling bathymetry.

The local metocean forcings data (winds, water levels, waves, and 

currents) available from NOAA coastal buoys and gauges were used to 

develop estimates of water levels, waves, currents, and sediment transport 

and morphology change inside, outside, and around the vicinity area of 

Waukegan Harbor. The ISGS installed two nearshore gauges, G1 and G2, 

for short-term water level and wave measurements at Waukegan Harbor 

in various duration from November 2017 to October 2018. The wave data 

were used in the model calibration for July–August 2018 and model 

verification for September–October 2018.

This report describes modeling details of nearshore coastal processes in 

the exterior and interior areas of Waukegan Harbor and variation 

at/around the entrance of the harbor. Different type of structural

alternatives were introduced into the modeling domain to determine how 

the shoaling changes in the navigation channel. The modeling of a large 

domain required using a spectral wave model (CMS-Wave) coupled to a

hydrodynamic model (CMS-Flow) for calculating changes in nearshore 

water levels, waves and currents, sediment transport, and morphology.

The use of a constant median grain size of D50=0.2 mm in the modeling 

is based on grab samples collected by ISGS in 2017. Details of the CMS 

modeling are provided in Chapter 4, Chapter 5, and the appendix. 

Effectiveness of alternatives can be quantified relative to Alt 0 by defining 

two performance evaluation metrics: a percent shoaling volume estimate 

and a maximum shoaling height. Table 5-1 and Figure 5-5 provide a 

summary of results for all alternatives. Overall, alternatives with high-
ERDC/CHL TR-20-12 67

crest elevation structures performed the best by achieving maximum 

reduction in shoaling in the AC and OH. 

Tables 5-2 to 5-6 summarize modeling results for three crest elevations.

Estimates of the sediment accumulation volume and maximum shoaling 

height in the AC, OH, and AM area are provided for these four 

alternatives. The mid-crest structures also performed well but low-crest 

structures did not. Alt 3 and Alt 5 with high-crest elevation were top 

performers achieving approximately 85% reduction in channel shoaling.

Higher cost estimates for high-crest elevation structures led to 

consideration of the mid-crest and low-crest structures. Alt 2c, Alt 2d, Alt 

3, and Alt 5 were further modeled for mid- and low-crest elevations due to 

the potentially reduced design costs of these alternatives. 

Because construction cost is proportional directly to the size of a structure 

(length, width, and height), estimates are also provided for the four 

alternatives with mid- and low-crest structures. Alt 2c and Alt 2d with 

mid-crest were the top performers while alternatives with low-crest 

structures did not perform well. A substantial design cost saving can be 

realized for the mid- and low-crest structures, but associated long-term 

maintenance cost can be high.

In addition to the shoaling volumes (accumulated sand) and height of 

shoaling metrics, Chapter 5 presented a number of 2D maps showing the 

spatial variation of morphological change in and around Waukegan Harbor. 

These maps display hot-spot areas developing in each alternative around 

the navigation channel and in other locations along the north breakwater 

and north beach. The hot-spot areas are of particular interest because these 

areas may require expansion (acreage) of the existing AM area.

In summary, Alt 2c, Alt 2d, Alt 3, and Alt 5 provided the best protection to 

the entrance of Waukegan Harbor by reducing shoaling significantly in 

navigation channel. Because cost estimates for high-crest structures were 

high, some mid- and low-crest alternatives were retained for further 

modeling. Design cost estimates for Alt 2c and Alt 2d with mid- and lowcrest elevations were substantially less than those of high-crest elevation. 

Ultimately, the design and maintenance cost, constructability of a system, 

as well as potential impacts on environment, will determine the alternative 

that can best meet future project needs.
ERDC/CHL TR-20-12 68

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Demirbilek, Z., L. Lin, O. G. Nwogu, K. K. Hathaway, W. C. Butler, J. H. Podoski, and 

T. D. Smith. 2016b. Assessment of Modifications for Improving Navigation at 

Hilo Harbor, Hawaii. ERDC/CHL TR-16-9. Vicksburg, MS: U.S. Army Engineer 

Research and Development Center.

Demirbilek, Z., L. Lin, O. G. Nwogu, W. C. Butler, K. K. Hathaway, and T. D. Smith. 

2015a. Kikiaola Light Draft Harbor Monitoring Plan Part 2: Numerical Wave 

Modeling for Evaluation of Structural Alternatives. ERDC/CHL TR-14-9. 

Vicksburg, MS: U.S. Army Engineer Research and Development Center.

Demirbilek, Z., L. Lin, O. G. Nwogu, J. A. Goo, and T. D. Smith. 2015b. Faleasao Harbor,

American Samoa: Investigation of Modifications for Improving Navigation. 

ERDC/CHL TR-15-15. Vicksburg, MS: U.S. Army Engineer Research and 

Development Center.

Demirbilek, Z., L. Lin, Donald L. Ward, and David B. King. 2015c. Modeling Study for 

Tangier Island Jetties, Tangier Island, Virginia. ERDC/CHL TR-14-8. 

Vicksburg, MS: U.S. Army Engineer Research and Development Center.

Demirbilek, Z., L. Lin, Earl Hayter, Colleen O’Connell, Michael M. Mohr, Shanon Chader,

and Craig Forgette. 2015d. Modeling of Waves, Hydrodynamics and Sediment 

Transport for Protection of Wetlands at Braddock Bay, New York. ERDC TR-14-

8. Vicksburg, MS: U.S. Army Engineer Research and Development Center.

Demirbilek, Z., and J. Rosati. 2011. Verification and Validation of the Coastal Modeling 

System, Report 1: Summary Report. ERDC/CHL TR-11-10: Report 1. Vicksburg, 

MS: U.S. Army Engineer Research and Development Center.

Demirbilek, Z., L. Lin, and A. Zundel. 2007. WABED Model in the SMS: Part 2. 

Graphical Interface. ERDC/CHL CHETN-I-74. Vicksburg, MS: U.S. Army 

Engineer Research and Development Center.
ERDC/CHL TR-20-12 69

Lin, L., and Z. Demirbilek. 2005. “Evaluation of Two Numerical Wave Models with Inlet 

Physical Model.” Journal of Waterway, Port, Coastal, and Ocean Engineering

ASCE 131(4): 149–161.

Lin, L., and Z. Demirbilek. 2012. Coupled BOUSS-2D and CMS-Wave Modeling 

Approach for Harbor Projects. ERDC/CHL CHETN-IV-84. Vicksburg, MS: U.S. 

Army Engineer Research and Development Center.

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Wave Processes Model for Coastal Inlets and Navigation Projects. ERDC/CHL 

TR-08-13. Vicksburg, MS: U.S. Army Engineer Research and Development 

Center.

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Wave Model for Inlets and Navigation Projects.” In Proceedings, Symposium to 

Honor Dr. Nicholas Kraus. Journal of Coastal Research Special Issue 59: 7–14.

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the Coastal Modeling System, Report 2: CMS-Wave. ERDC/CHL TR-11-10: 

Report 2. Vicksburg, MS: U.S. Army Engineer Research and Development Center.

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Theuerkauf. 2019. Sediment Budget for the North Illinois Shore from the 

Wisconsin Border to Wilmette Harbor. ERDC/CHL TR-19-13. Vicksburg, MS: 

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ERDC/CHL TR-20-12 70

Appendix: Description of the CMS

The CMS was used in this study to provide estimates of waves and water 

levels in Buffalo Harbor for studies involving repairs of breakwaters and a 

seawall. A brief description of the CMS is provided here for completeness. 

Figure A-1 shows the modular framework of the CMS and its components. 

CMS consists of numerical models for waves, flows, and sediment 

transport and morphology change in coastal areas. This modeling system 

includes representation of relevant nearshore processes for practical 

applications of navigation channel performance and sediment 

management at coastal inlets and adjacent beaches. The development and 

enhancement of CMS capabilities continues to evolve as a research and 

engineering tool for desk-top computers. CMS uses the SMS interface for 

grid generation and model setup as well as plotting and post-processing. 

Additional information about CMS is available (Demirbilek and Rosati 

2011; Demirbilek et al. 2007a,b,c; Lin and Demirbilek 2012, 2005; Lin et al. 

2011a,b, 2008).

Figure A-1. The CMS framework and its components. 
ERDC/CHL TR-20-12 71

CMS uses the SMS interface for grid generation and model setup, as well 

as plotting and post-processing. The V&V Report 1 (Demirbilek and Rosati 

2011) and Report 2 (Lin et al. 2011) have detailed information about the 

CMS-Wave features and evaluation of model’s performance skills in a 

variety of applications. Report 3 and Report 4 by Sanchez et al. (2011a and 

2011b) describe coupling of wave-flow models and hydrodynamic and 

sediment transport and morphology change aspects of CMS-Flow. The 

performance of the CMS for a number of applications is summarized in 

Report 1, and details are described in the three companion V&V Reports 2, 

3, and 4.

The CMS-Wave is a spectral wave model and was used in this study given 

the large extent of modeling domain over which wave estimates were 

required. Details of the wind-wave modeling are described in Chapter 3 of 

this report. The main wave processes included in the CMS-Wave are windwave generation and growth, diffraction, reflection, dissipation due to 

bottom friction, white-capping and breaking, wave-current interaction, 

wave runup, wave setup, and wave transmission through structures. The 

height and direction of waves approaching the Buffalo Harbor change due 

to wave shoaling, refraction, diffraction, reflection, and breaking. Waves 

propagating toward the breakwaters interact with bathymetry, 

surrounding land features and coastal structures. These features affect 

waves propagating and reaching the protective structures, waves going 

over these structures and getting into the interior of harbor, which can 

affect navigation and utilization of harbor. 

CMS-Wave model solves the steady-state wave-action balance equation on 

a non-uniform Cartesian grid to simulate steady-state spectral 

transformation of directional random waves at and around the 

breakwaters in Buffalo Harbor. CMS-Wave is designed to simulate wave 

processes with ambient currents in navigation channels, coastal inlets, and 

harbors. The model can be used either in half-plane or full-plane mode for 

spectral wave transformation (Lin et al. 2008; Demirbilek et al. 2007b). 

The half-plane mode is the default because in this mode CMS-Wave can

run more efficiently as waves are transformed primarily from the lake 

ward boundary toward shore. See Lin et al. (2011, 2008) for features of the 

model and step-by-step instructions with examples for application of 

CMS-Wave to a variety of coastal inlets, ports, structures, and other 

navigation problems. Publications listed in the V&V reports and this report 

provide additional information about CMS-Wave and its engineering 
ERDC/CHL TR-20-12 72

applications. Additional information about CMS-Wave is available from the 

CIRP website: http://cirp.usace.army.mil/wiki/CMS-Wave.

Since the flow model was also used in this study, brief information is 

provided. The CMS-Flow is a 2D shallow-water wave model for 

hydrodynamic modeling (calculation of water level and current). Both 

the explicit and implicit versions of flow (circulation) model are available 

to provide estimates of water level and current given the tides, winds, 

and river flows as boundary conditions. CMS-Flow calculates 

hydrodynamic (depth-averaged circulation) sediment transport, 

morphology change, and salinity due to tides, winds, and waves. It was 

used in this study with CMS-Wave to check water level changes in the 

harbor caused by winds, waves, and river flows.

The hydrodynamic model solves the conservative form of the shallowwater equations that includes terms for the Coriolis force, wind stress, 

wave stress, bottom stress, vegetation flow drag, bottom friction, wave 

roller, and turbulent diffusion. Governing equations are solved using the 

finite volume method on a non-uniform Cartesian grid. Finite-volume 

methods are a class of discretization schemes, and this formulation is 

implemented in finite-difference for solving the governing equations of 

coastal wave, flow, and sediment transport models. See the V&V Reports 3 

and 4 by Sanchez et al. (2011a,b) for the preparation of the flow model at 

coastal inlet applications. Additional information about CMS-Flow is 

available from the CIRP website: http://cirp.usace.army.mil/wiki/CMS-Flow.

Although hydrodynamic, sediment transport, and morphology change 

modeling were not considered in this study, it is noted for future reference 

that there are three sediment transport models available in CMS-Flow: a 

sediment mass balance model, an equilibrium advection-diffusion model, 

and a non-equilibrium advection-diffusion model. Depth-averaged salinity 

transport is simulated with the standard advection-diffusion model and 

includes evaporation and precipitation. The V&V Reports 1 through 4 

describe the integrated wave-flow-sediment transport and morphology 

change aspects of CMS-Flow. The performance of CMS-Flow is described 

for a number of applications in the V&V reports. 
ERDC/CHL TR-20-12 73

Unit Conversion Factors

Multiply By To Obtain 

acres 4,046.873 square meters

cubic yards 0.7645549 cubic meters

feet 0.3048 meters

knots 0.5144444 meters per second

miles per hour 0.44704 meters per second

miles (U.S. nautical) 1.852 kilometers

miles (U.S. statute) 1.609347 kilometers
ERDC/CHL TR-20-12 74

Acronyms and Abbreviations

2D two-dimensional 

AC Approach Channel 

AM Advance Maintenance 

CHL Coastal and Hydraulics Laboratory 

CIRP Coastal Inlets Research Program

CMS Coastal Modeling System 

FID Federal Interest Determination 

GLCFS Great Lakes Coastal Forecasting System

GMT Greenwich Mean Time

IDNR Illinois Department of Natural Resources 

IGLD 85 International Great Lakes Datum of 1985

IH Inner Harbor 

ISGS Illinois State Geological Survey 

LRC Chicago District 

LWD low water datum

NB North Breakwater

NDBC National Data Buoy Center 

NGDC National Geophysical Data Center 

NOAA National Oceanic and Atmospheric Administration

O&M Operations & Maintenance

OH Outer Harbor 

Q/FY Quarter/Fiscal Year

SMS Surface-water Modeling System 

USACE US Army Corps of Engineers 

V&V Verification and Validation 

WIS Wave Information Studies 
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PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE

July 2020

2. REPORT TYPE 

Final Report

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Investigation of Shoaling in the Federal Navigation Channel, Waukegan Harbor, Illinois

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

280H46

6. AUTHOR(S)

Zeki Demirbilek, Lihwa Lin, John A. Wethington, Mike Nguyen, David F. Bucaro, 

Monica Ott, Phillip Horstman, Joel L. Schmidt, Alex R. Hoxsie, Steven R. Goodpaster, 

Kluza, and Ethan J. Theuerkauf 

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Coastal and Hydraulics Laboratory

U.S. Army Engineer Research and Development Center

3909 Halls Ferry Road

Vicksburg, MS 39180-6199

8. PERFORMING ORGANIZATION 

REPORT NUMBER

ERDC/CHL TR-20-12

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Army Corps of Engineers, Chicago District

231 S. LaSalle Street, Suite 1500

Chicago, IL 60604

10. SPONSOR/MONITOR'S ACRONYM(S)

LRC

11. SPONSOR/MONITOR'S REPORT 

NUMBER(S)

12. DISTRIBUTION/AVAILABILITY STATEMENT

Approved for public release; distribution is unlimited

13. SUPPLEMENTARY NOTES

14. ABSTRACT

Persistent and excessive shoaling occurs in the Outer Harbor and Approach Channel of the Waukegan Harbor, Illinois. This report 

describes a numerical modeling study performed for the US Army Corps of Engineers, Chicago District, to evaluate the existing harbor 

and eleven structural alternatives for three crest elevations. This report provides details of numerical modeling study, analysis of field 

data, and estimates of shoaling. The focus of the study is the investigation of a variety of structural solutions intercepting and/or 

diverting sediments to reduce shoaling in the navigation channel. These include breakwaters, groins, spurs, and structural extensions 

with varying length and crest elevation connecting to the north beach and existing north breakwater. Estimates of both shoaling volume 

and height are developed with and without project using an integrated wave-flow-sediment transport numerical modeling approach. 

Quantitative reduction estimates are provided for each structural alternative investigated.

15. SUBJECT TERMS

Breakwaters, Dredging, Harbors—Design, Navigation, Section 107 Study, Sedimentation and deposition, Sediment transport, Shoaling,

Water currents, Water levels, Water waves, Waukegan (Ill.)

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 

ABSTRACT

Unclassified

18. NUMBER OF 

PAGES

85

19a. NAME OF RESPONSIBLE PERSON

a. REPORT Zeki Demirbilek

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified 19b. TELEPHONE NUMBER (Include area code)

601.634.2834

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