U.S. Department of the Interior

U.S. Geological Survey

Pamphlet to accompany

Scientific Investigations Map 3185

Prepared in cooperation with the DuPage County Stormwater Management Division

Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, 

Wood Dale, Illinois
Cover. Photographs clockwise from upper left: Flooding on Edgebrook Road, downstream from the Wood Dale 

streamgage, taken July 2011, at a gage height of 14 ft; Irving Park Road bridge pier water-surface elevation reference, 

taken July 2011; High-water mark (HWM) photograph, taken in August 2010, during HWM collection following the 

July 2010 flood event; Flooding in floodplain downstream from the gage, taken Sept. 2008, at a gage height of 14.2 ft.
Flood-Inundation Maps for a 1.6-mile reach 

of Salt Creek, Wood Dale, Illinois

By David T. Soong, Elizabeth A. Murphy, and Jennifer B. Sharpe

Scientific Investigations Map 3185

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the DuPage County Stormwater 

Management Division
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2012

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

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U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Soong, D.T., Murphy, E.A., and Sharpe, J.B., 2012, Flood-inundation maps for a 1.6-mile reach of Salt Creek, Wood 

Dale, Illinois: U.S. Geological Survey Scientific Investigations Map 3185, 8 p. pamphlet, 14 sheets, scale 1: 6,500. 
iii

Contents

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

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

Purpose and Scope ..............................................................................................................................1

Study Area Description........................................................................................................................2

Previous Studies ...................................................................................................................................2

Constructing Water-Surface Profiles.........................................................................................................2

Hydrologic Data.....................................................................................................................................4

Topographic/Bathymetric Data ..........................................................................................................4

Energy Loss Factors .............................................................................................................................4

Model Verification and Performance ................................................................................................4

Development of Water-Surface Profiles...........................................................................................4

Inundation Mapping ......................................................................................................................................5

Inundation Verification.........................................................................................................................5

Salt Creek, Illinois, Flood-Inundation Maps on the Internet..........................................................7

Uncertainty Associated with Inundation Maps...............................................................................7

Acknowledgments.........................................................................................................................................7

Summary..........................................................................................................................................................7

References Cited............................................................................................................................................8

Figures 

1. Map showing location of study reach for Salt Creek, Illinois, and location 

of USGS streamgage site ............................................................................................................3

2. Graph showing stage-discharge relation generated by the FEQ model for the 

September 2008 flood with historical discrete discharge measurements taken 

at the Salt Creek at Wood Dale streamgage.............................................................................5

3. Map showing high-water marks from the July 2010 flood plotted with the 

inundation surface for the 14-ft gage height at the Salt Creek at Wood Dale 

streamgage....................................................................................................................................6

Tables 

1. USGS streamgage and miscellaneous site information for study area, 

Salt Creek, Illinois .........................................................................................................................2

2. 1.0 percent annual exceedance probability peak-discharge estimates 

and drainage areas for selected locations on Salt Creek near Wood Dale, 

Illinois..............................................................................................................................................4
iv

Sheets

Flood-inundation maps for a 1.6-mile reach of Salt Creek at Wood Dale, Illinois, 

corresponding to USGS Streamgage Salt Creek at Wood Dale (sta. no. 05531175) 

for gage height of:

1. 11 feet.

2. 11.5 feet.

3. 12 feet.

4. 12.5 feet.

5. 13 feet.

6. 13.5 feet.

7. 14 feet.

8. 14.5 feet.

9. 15 feet.

10. 15.5 feet.

11. 16 feet.

12. 16.5 feet.

13. 17 feet.

14. 17.5 feet.
v

Multiply By To obtain

Length

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2

) 0.09290 square meter (m2)

square mile (mi2

) 2.590 square kilometer (km2) 

Flow rate

cubic foot per second (ft3

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

Hydraulic gradient

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

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

(NAVD 88).

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

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

Conversion Factors

Inch/Pound to SI

Abstract

Digital flood-inundation maps for a 1.6-mile reach of Salt 

Creek from upstream of the Chicago, Milwaukee, St. Paul & 

Pacific Railroad to Elizabeth Drive, Wood Dale, Illinois, were 

created by the U.S. Geological Survey (USGS) in cooperation 

with the DuPage County Stormwater Management Division. 

The inundation maps, which can be accessed through the 

USGS Flood Inundation Mapping Science Web site at http://

water.usgs.gov/osw/flood_inundation/ depict estimates of the 

areal extent of flooding corresponding to selected water levels 

(gage heights) at the USGS streamgage on Salt Creek at Wood 

Dale, Illinois (station number 05531175). Current conditions 

at the USGS streamgage may be obtained on the Internet at 

http://waterdata.usgs.gov/usa/nwis/uv?05531175. 

In this study, flood profiles were computed for the stream 

reach by means of a one-dimensional unsteady flow Full 

EQuations (FEQ) model. The unsteady flow model was verified by comparing the rating curve output for a September 

2008 flood event to discharge measurements collected at the 

Salt Creek at Wood Dale gage. The hydraulic model was then 

used to determine 14 water-surface profiles for gage heights 

at 0.5-ft intervals referenced to the streamgage datum and 

ranging from less than bankfull to approximately the highest 

recorded water level at the streamgage. The simulated watersurface profiles were then combined with a Geographic Information System (GIS) Digital Elevation Model (DEM) (derived 

from Light Detection and Ranging (LiDAR) data) in order to 

delineate the area flooded at each water level. The areal extent 

of the inundation was verified with high-water marks from a 

flood in July 2010 with a peak gage height of 14.08 ft recorded 

at the Salt Creek at Wood Dale gage.

The availability of these maps along with Internet information regarding current gage height from USGS streamgages 

provide emergency management personnel and residents with 

information that is critical for flood response activities such 

as evacuations and road closures as well as for post-flood 

recovery efforts.

Introduction 

DuPage County is part of the Chicago, Illinois, metropolitan area with an estimated population of 932,541 in 2009

(U.S. Census Bureau, 2011). Portions of DuPage County have 

experienced severe flooding numerous times; most notably in 

August 1987, September 2008, and July 2010. Flood plains 

within DuPage County are highly urbanized and contain a mix 

of residential and commercial structures.

Prior to this study, DuPage County officials have relied 

on several information sources to make decisions on how to 

best alert the public about impending flooding, and to mitigate flood damages. DuPage County has developed updated 

hydrologic and hydraulic models that enable the County to 

provide flood warning to citizens and to operate flood control 

reservoirs (Price, 2011). The hydrologic and hydraulic models 

developed by the County are more recent than those developed 

for the Federal Emergency Management Agency (FEMA) 

Flood Insurance Study (FIS) for DuPage County, Illinois, and 

Incorporated Areas dated December 16, 2004 (FEMA, 2004). 

An additional source of information is the U.S. Geological 

Survey (USGS) streamgage Salt Creek at Wood Dale, Ill. (sta. 

no. 05531175), from which current or historical water levels 

(gage heights) can be obtained. Although USGS current gage 

height is particularly useful for residents in the immediate 

vicinity of a streamgage, it is of limited use to residents farther 

upstream or downstream because the water-surface elevation 

is not constant along the entire stream channel. 

Purpose and Scope

The purpose of this report is to (1) describe the development of a series of estimated flood-inundation maps for a 

1.6-mile reach of Salt Creek between just upstream of the 

Chicago, Milwaukee, St. Paul & Pacific Railroad and Elizabeth Drive near Wood Dale, Illinois, and (2) provide users 

with a library of flood-inundation maps that correspond to 

water levels referenced to the water-surface elevation (gage 

heights) at the USGS streamgage on Salt Creek at Wood Dale, 

Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, 

Wood Dale, Illinois

By David T. Soong, Elizabeth A. Murphy, and Jennifer B. Sharpe
2 Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, Wood Dale, Illinois

Illinois, ranging from below bankfull (11 ft) to the maximum 

observed water level at the streamgage (17.5 ft). This report is 

a description of the maps and other flood information available 

on the USGS Flood Inundation Mapping Science Web site at 

http://water.usgs.gov/osw/flood_inundation/.

Study Area Description

Salt Creek is in northeast Illinois in the Central Lowland 

physiographic province. The drainage area is 74.7 mi2

 at the 

USGS Wood Dale streamgage (table 1; USGS, 2011) with 

a total drainage area of approximately 117 mi2

 in DuPage 

County (DuPage County Department of Economic Development and Planning, Division of Stormwater Management, 

2011). The headwaters originate in Lake County, and the 

stream flows generally southward through DuPage County. 

The Salt Creek watershed is divided between Upper Salt Creek 

and Lower Salt Creek (fig.1). The Lower Salt Creek watershed begins north of the DuPage county border, flows through 

DuPage County and ends at the junction with the Des Plaines 

River. There are eight major tributaries to Lower Salt Creek 

that join the main stem as it flows through DuPage County 

(DuPage County Department of Economic Development and 

Planning, Division of Stormwater Management, 2011). The 

study reach is approximately 1.6 miles long (fig. 1), has an average top-of-bank channel width of about 80 ft and an average 

channel slope of 2 ft/mi based on cross-section information 

in the FEQ model input file. The basin terrain is generally flat 

and has been under development with residential, commercial 

and industrial areas since 1950 and population has increased 

600 percent between 1950 and 2002 (DuPage County Department of Economic Development and Planning, Division of 

Stormwater Management, 2011). The land use along the study 

reach is commercial north of Irving Park Road, residential 

through the middle section of the reach, and forest preserve 

land through the south part of the study reach (fig.1). The main 

channel within the study reach has a railroad and two major 

road crossings. 

Previous Studies 

The current FIS for DuPage County, Ill., and Incorporated Areas dated December 16, 2004 (FEMA, 2004) 

includes the Salt Creek Main Stem study completed by the 

Soil Conservation Service and the Illinois State Water Survey 

in 1978. However, since that time new models have been 

developed by the County to utilize unsteady flow techniques 

and update information on structures along Salt Creek. The 

new models are a Hydrological Simulation Program—FORTRAN (HSPF) hydrologic model to simulate flows, and a Full 

EQuations (FEQ) hydraulic model to route the flows (Price, 

2011). Estimates of the peak discharges for the 1.0 percent 

annual exceedance probability (100-year) flood along the Salt 

Creek, as shown in table 2 for the study reach, were described 

in FEMA (2004). 

Constructing Water-Surface Profiles

The water-surface profiles used to produce the 14 floodinundation maps for this study were computed by using FEQ, 

version 10.61 (Franz and Melching, 1997a). FEQ is a onedimensional unsteady flow model for simulation of watersurface profiles. The FEQ model input file generally contains 

information about the stream hydrograph, the hydraulic 

properties of the floodplain and structures, the connectivity 

of stream cross-sections and structures, boundary conditions, 

initial conditions, and nodes storing water-surface elevations 

or hydrograph information (Franz and Melching, 1997a). 

The FEQ model was used to model Salt Creek because it is 

designed to be flexible and capable of modeling the complexity of the various control structures in this highly urbanized 

watershed. The FEQ model used to construct the water-surface 

profiles for this study reach was extracted from the larger FEQ 

model used to simulate the entire Salt Creek reach (Christopher B. Burke Engineering, 2010). The model was shortened 

from the original model to allow more certainty at the 

boundary conditions.

Table 1. USGS streamgage and site information for study area, Salt Creek, Illinois. 

[mi2, square mile; ft, feet]

Station name Station number Drainage area (mi2) Latitude Longitude Period of record

Maximum recorded 

elevation at gage 

(ft above NAVD 88) and date

Salt Creek at 

Wood Dale 05531175 74.7 41o

 57′50′′ 87o59′02′′ Oct. 1999 to 

 current year

 16.58 ft

 Sept. 14, 2008
Constructing Water-Surface Profiles 3

87°59'30" 87°59'

41°58'

41°57'30"

0 .05 .15 .2 .25 MILES

0 .05 .1 .15

.1

.2 .25 KILOMETERS

Limits of the

Salt Creek study

Salt Creek

USGS streamgage

and number

EXPLANATION

05531175

CHICAGO, MILWAUKEE, ST. PAUL & PACIFIC RAILROAD

IRVING PARK ROAD

ADDISON ROAD

ELIZABETH DRIVE

19

05531175

Creek

Salt

Orthography from the Illinois Natural Resources

Geospatial Data Clearinghouse, accessed in 2005 at

http://www.isgs.uiuc.edu/nsdihome/webdocs/cua05/

Salt Creek

Watershed

Chicago

metropolitan area

ILLINOIS

Study reach

Des

Plaines

River

DuPage River

Salt Creek

Addison Creek

COOK COUNTY

LAKE COUNTY

Upper

Salt Creek

Watershed

DUPAGE

COUNTY

Lower

Salt Creek

Watershed

Figure 1. Map showing location of study reach for Salt Creek, Illinois, and location of USGS streamgage site.
4 Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, Wood Dale, Illinois

Hydrologic Data

The study area hydrologic network consists of one 

streamgage (fig. 1; table 1). This gage was installed in October 

1999 and has been measuring water levels (gage heights) continuously since installation. All water-surface elevations are 

referenced to North American Vertical Datum of 1988 (NAVD 

88). In addition, some discrete discharge measurements were 

made at this site during periods of moderate to high flow and 

were used for model verification. High-water marks documented by the USGS following flooding in July 2010 were 

also used for verification of mapping extent. 

A normal depth boundary condition was assumed 

downstream (with a friction slope estimated from the average 

streambed slope through the reach) at Interstate 290, approximately 1.1 miles downstream from Elizabeth Drive.

Topographic/Bathymetric Data

The digital elevation model data were derived from a 3-ft 

horizontal resolution LiDAR dataset with a vertical accuracy 

sufficient to produce 1-foot contours. The LiDAR data were 

obtained from DuPage County (John McLaughlin, DuPage 

County Stormwater Management Division, written commun., 

2009). The surveying for the study reach was done by Mackie 

Consultants, LLC. in 2003 and processed for the FEQ model 

using an ArcInfo (ESRI, 1999b) script program developed by 

DuPage County GIS staff (Christopher B. Burke Engineering, 

Ltd, 2010). Because the FEQ model was updated in 2010 for 

DuPage County by Christopher B. Burke Engineering, Ltd., 

the USGS did not update or do any additional field verification 

of the geometry in the FEQ model. 

Energy Loss Factors

Field observations and high-resolution aerial photographs 

were used to select initial (pre-calibration) Manning’s roughness coefficients (“n” values) for energy (friction) loss calculations. The final Manning’s n values used ranged from 0.06 to 

0.065 for the main channel and 0.085 to 0.2 for the overbank 

areas modeled in this analysis. The main channel bed is mostly 

sand, gravel, and silt and the overbank areas are vegetated 

with some areas having shrub and tree cover.

As described in the FEQ model documentation prepared 

by Christopher B. Burke Engineering, Ltd. (2010), the energy 

losses at bridge crossings were modeled with a computer 

model for Water-Surface PROfile computations (WSPRO) 

(Shearman, 1990) and Full EQuations UTilLties (FEQUTL) 

commands (Franz and Melching, 1997b).

Model Verification and Performance

The FEQ model was run in unsteady mode for the event 

of September 12–21, 2008, with flows ranging from 71 ft3

/s 

to 3,876 ft3

/s. The simulated discharge hydrograph from the 

observed stage (gage height) hydrograph data at the Wood 

Dale gage was then input at the upstream end of the reach 

(near the Chicago, Milwaukee, St. Paul & Pacific Railroad). 

The unsteady FEQ model output was used to create a stagedischarge relation at the gage that was compared to discrete 

discharge measurements taken at various times throughout the 

gage history (fig. 2).

Because FEQ simulates unsteady flow, the stagedischarge relation plots as a loop or series of loops, depending 

on the dynamic nature of the particular hydrograph. Because 

the loop is so narrow for this model scenario (approximately 

0.5 ft or less) the difference in the profiles resulting from the 

rising or falling limb of the hydrograph was less than the resolution of the LiDAR-derived DEM. The results demonstrate 

that the model is capable of simulating accurate water levels 

over a wide range of flows in the basin. More discussion of the 

accuracy of the simulated inundation surfaces can be found in 

the “Inundation Verification” section.

Development of Water-Surface Profiles

Profiles were developed for a total of 14 gage heights 

at 0.5-ft intervals. The gage heights ranged between 11.0 

ft and 17.5 ft as referenced to the Salt Creek at Wood Dale 

streamgage (sta. no. 05531175). This range of gage heights 

includes below bankfull to almost the highest recorded gage 

height at the gage. A separate FEQ simulation was run for each 

mapped gage height at the streamgage with the input discharge 

required to generate the correct gage height determined by 

trial and error. 

Table 2. 1.0 percent annual exceedance probability peak-discharge estimates and drainage areas for 

selected locations on Salt Creek near Wood Dale, Illinois (from FEMA, 2004).

[mi2, square miles; ft3/s, cubic feet per second; ft, feet]

Location on Salt Creek Drainage area

(mi2

)

Discharge estimate

(ft3/s)

Approximately 660 ft upstream of Elizabeth Drive 73.0 3,524

Approximately 527 ft downstream of Irving Park Road 71.4 3,502

Approximately 792 ft upstream from Chicago, 

Milwaukee, St. Paul & Pacific Railroad 70.9 3,484
Inundation Mapping 5

Inundation Mapping

Flood-inundation maps were developed for the 14 watersurface profiles generated for the gage heights observed at 

the Salt Creek at Wood Dale gage. The maps were created in 

an ArcMap (Ormsby and others, 2010) GIS by combining the 

water-surface profiles and DEM data. Estimated flood-inundation boundaries for each simulated profile were created by 

using a DEM with a 5-foot cell size, modeled cross sections, 

and water-surface elevations for specific pre-defined gage 

heights for the cross sections derived from FEQ hydraulic 

model. Water-surface elevation values were joined to the corresponding cross section and a water-level surface for each 

pre-defined gage height was generated by using an Arc Macro 

Language (AML) (ESRI, 1999a) script modified from an AML 

provided by the Illinois Department of Natural Resources 

(Rick Gosch, Illinois Department of Natural Resources, written commun., 2009). The inundation surface was then created 

by subtracting the ground-surface DEM from the water-level 

surface. The maps show estimated flood-inundated areas overlaid on high-resolution, georeferenced, aerial photographs of 

the study area for each of the water-surface profiles that were 

generated by the hydraulic model for every half foot change in 

gage height ranging from 11 to 17.5 ft.

Inundation Verification

 High-water marks were collected by the USGS during 

the July 2010 flood. These high-water marks were compared 

to the extent of the inundation mapping. The peak gage height 

for the July 2010 flood at the Salt Creek at Wood Dale gage 

was 14.08 ft. This gage height corresponds to a water-surface 

elevation of 677.08 ft (all elevations referenced to NAVD88). 

The high-water marks range in elevation from 669.2 to 

676.8 ft. Excluding the 669.2 high-water mark because it 

appears to inaccurately portray the elevation of the high-water, 

the range is from 675.3 to 676.8 ft (fig. 3). The two high-water 

marks collected closest to the gage (elevations of 676.7 and 

676.8 ft) are most similar to the elevation of the water-surface 

peak at the gage (677.08 ft). A number of the high-water 

marks were collected near the bend of the creek where the 

model may be less able to capture the complexity of the flow. 

It should also be noted that the simulated water-surface profile 

drops approximately 2.2 feet between Irving Park Road and 

Elizabeth Drive, so the water-surface elevation would be lower 

in the southern part of the reach than it is near the gage.

Eight of the nine high-water marks are within the mapped 

area for the 14 ft gage height. One observed high-water mark, 

at a water-surface elevation of 675.5 ft, is located approximately 20 feet beyond the inundation surface boundary for the 

14 ft gage height and approximately 10 ft beyond the inundation surface boundary for the 14.5 ft gage height (note that the 

cell size of the mapping DEM is 5 feet). This high-water mark 

was measured on the Forest Preserve Path near a structure 

crossing Salt Creek. It appears that this path was not included 

in the topographic data and is likely at a lower elevation than 

is represented in the mapping DEM, which could explain the 

discrepancy in elevation between the inundation surface and 

the observed high-water mark.

The high-water marks help to verify the accuracy of the 

inundation surface. All the high-water marks collected were 

below the peak elevation measured at the gage and all but one 

was within the inundation boundary predicted by the model.

Discharge rating

Measurement

EXPLANATION

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

668 670 672 674 676 678 680

Stage, in feet

Discharge, in cubic feet per second

Figure 2. Graph showing stage-discharge relation generated by the FEQ 

model for the September 2008 flood with historical discrete discharge 

measurements taken at the Salt Creek at Wood Dale streamgage. The 

modeled reach extended from upstream of the Chicago, Milwaukee, St. 

Paul & Pacific Railroad to Interstate 290.
6 Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, Wood Dale, Illinois

Figure 3. Map showing high-water marks from the July 2010 flood plotted with the inundation surface for the 14-ft gage height 

(677 feet NAVD88) at the Salt Creek at Wood Dale streamgage.

0 0.1 0.2 0.3 0.4 0.5 MILES

0 0.1 0.2 0.3 0.4 0.5 KILOMETERS

Flood-inundation area

Limits of the Salt Creek study

High-water mark with elevation

USGS streamgage and number

EXPLANATION

05531175

19 State route marker

Flow arrow—Indicates direction

of water flow

IRVING PARK ROAD

ADDISON ROAD

ELIZABETH DRIVE

19

05531175

87°59'40" 87°59'20" 87°59'

41°58'

41°57'40"

41°57'20"

WOOD DALE ROAD

Creek

Salt

669.2

675.7

675.5

675.6

675.3

675.5 675.7

676.7

676.8

Orthography from the Illinois Natural Resources Geospatial Data Clearinghouse,

accessed in 2005 at http://www.isgs.uiuc.edu/nsdihome/webdocs/cua05/

Inundation surface corresponds to a gage height of 14.0 ft at

U.S. Geological Survey streamgage at Wood Dale, Ill., (station number 05531175)

CHICAGO, MILWAUKEE, ST. PAUL & PACIFIC RAILROAD
Summary 7

Salt Creek, Illinois Flood-Inundation Maps on 

the Internet

A USGS Flood Inundation Mapping Science World Wide 

Web portal has been established at URL http://water.usgs.gov/

osw/flood_inundation/ to provide estimated flood-inundation 

information to the public. The maps from this study showing 

the extent of inundated areas can be downloaded in three 

electronic file formats from that portal: (1) GIS shapefile format (2) KMZ file format, and (3) Portable Document Format 

(PDF). Users can print out formatted maps or create customized maps by using available GIS data layers. The estimated 

flood-inundation maps are displayed in sufficient detail to note 

the extent of flooding with respect to individual structures so 

that preparations for flooding and decisions for emergency 

response can be performed efficiently. 

Uncertainty Associated with Inundation Maps

Although the flood-inundation maps represent the boundaries of inundated areas with a distinct line, some uncertainty 

is associated with these maps. The flood boundaries shown 

were estimated based on gage heights (water-surface elevations) and streamflows at a selected USGS streamgage. Watersurface elevations along the stream reaches were estimated by 

hydraulic modeling, assuming unobstructed flow, and using 

gage height and hydrologic conditions anticipated at the USGS 

streamgage. The hydraulic model reflects the land-cover characteristics and any bridge, dam, levee, or other hydraulic structures existing in 2010. Unique meteorological factors (timing 

and distribution of precipitation) may cause actual streamflows 

along the modeled reach to vary from those assumed during a 

flood, which may lead to deviations in the water-surface elevations and inundation boundaries shown. Additional areas may 

be flooded due to unanticipated conditions such as: changes 

in the streambed elevation or roughness, backwater into major 

tributaries along a main stem river, or backwater from localized debris or ice jams. The accuracy of the floodwater extent 

portrayed on these maps will vary with the accuracy of the 

digital elevation model used to simulate the land surface. 

Inundated areas shown should not be used for navigation, regulatory, permitting, or other legal purposes. Although 

USGS intends to make this server available 24 hours a day, 

7 days a week, timely delivery of data and products from 

this server through the Internet is not guaranteed. The USGS 

provides these maps “as-is” for a quick reference, emergency 

planning tool but assumes no legal liability or responsibility 

resulting from the use of this information.

Acknowledgments

The authors wish to thank the many local, State, and 

Federal agencies that provided funding and cooperated in the 

operation and maintenance of the gage used for this study, 

especially John McLaughlin and other staff at the DuPage 

County Stormwater Management Division.

Summary

A series of estimated flood-inundation maps were developed in cooperation with the DuPage County Department of 

Economic Development & Planning for Salt Creek between 

upstream of the Chicago, Milwaukee, St. Paul & Pacific 

Railroad and Elizabeth Drive in Wood Dale, Illinois. These 

maps, available at URL (http://water.usgs.gov/osw/flood_

inundation/), in conjunction with the real-time gage height 

data from the USGS streamgage at Salt Creek at Wood Dale, 

Ill. (sta. no. 05531175), can help to guide the public in taking 

individual safety precautions and can provide city officials 

with a tool to efficiently manage emergency flood operations 

and flood mitigation efforts. 

The maps were developed by using the FEQ and ArcMap 

programs to compute water-surface profiles and to delineate 

estimated flood-inundation areas for selected gage heights. 

The maps show estimated flood-inundation areas overlaid on 

high-resolution, georeferenced, aerial photographs of the study 

area for stream gage heights between 11.0 ft and 17.5 ft at the 

Salt Creek at Wood Dale streamgage. 
8 Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, Wood Dale, Illinois

References Cited

Christopher B. Burke Engineering, Ltd., 2010, Floodplain 

Mapping Report and Documentation for Lower Salt Creek 

Watershed, Prepared for DuPage County Department of 

Engineering Division of Stormwater and Environmental 

Concerns. CBBEL project no. 09–0101.00001.

DuPage County Department of Economic Development and 

Planning, Division of Stormwater Management, 2011, 

Stormwater Management: accessed on January 31, 2011 at 

URL http://ec.dupageco.org/dec/saltcreek.htm

Environmental Systems Research Institute (ESRI), 1999a, 

ARC Macro Language—Self-study workbook, Developing 

ARC/INFO menus and macros with AML: Redlands, Calif., 

ESRI Press, 828 p. ISBN 978-1879102187

Environmental Systems Research Institute (ESRI), 1999b, 

Understanding GIS—The ARC/INFO method: Redlands, 

Calif., ESRI Press, Inc., 602 p, ISBN 978-1879102019

Federal Emergency Management Agency (FEMA), 2004, 

Flood Insurance Study, A Report of Flood Hazards in 

DuPage County, Illinois and Incorporated Areas: Flood 

Insurance Study Number 17043CV002A, variously paginated.

Franz, D.D., and Melching, C.S., 1997a, Full Equations (FEQ) 

model for the solution of the full, dynamic equations of 

motion for one-dimensional unsteady flow in open channels 

and through control structures: U.S. Geological Survey 

Water-Resources Investigations Report 96-4240, 258 p. 

Franz, D.D., and Melching, C.S., 1997b, Full Equations Utility 

(FEQUTL) model for the approximation of hydraulic characteristics of open channels and control structures during 

unsteady flow: U.S. Geological Survey Water-Resources 

Investigations Report, 97-4037, 205 p. 

Ormsby, Tim, Napoleon, E.J., Burke, Robert, Groessel, Carolyn, and Bowden, Laura, 2010, Getting to Know ArcGIS 

Desktop: Redlands, Calif., ESRI Press, 604 p., ISBN: 

9781589482609 

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Shearman, J.O., 1990, User’s manual for WSPRO–A computer 

model for water surface profile computations: Washington, 

D.C., U.S. Department of Transportation, U.S. Federal 

Highway Administration report no. FHWA–IP–89–027, 

177 p. 

U.S. Census Bureau, 2011, DuPage County QuickFacts: 

accessed on Jan. 26, 2011 at http://quickfacts.census.gov/

qfd/states/17/17043.html.

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Creek at Wood Dale, IL: U.S. Geological Survey, Water 

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cd=USGS&.

Publishing support provided by:

Denver Publishing Service Center

Manuscript approved for publication Oct. 12, 2011 

For more information concerning this publication, contact:

Director, Illinois Water Science Center

U.S. Geological Survey

1201 W. University Avenue, Suite 100 

Urbana, IL 61801 

Or visit the Illinois Water Science Center Web site at: 

http://il.water.usgs.gov

This report is available at: http://pubs.usgs.gov/sim/3185
Soong and others—Flood-Inundation Maps for a 1.6-mile reach of Salt Creek, Wood Dale, Illinois—Scientific Investigations Map 3185