Prepared in cooperation with the New Jersey Department of Environmental Protection

Flood-Inundation Maps for the Saddle River 

from Upper Saddle River Borough to Saddle River Brorough, 

New Jersey, 2013

Pamphlet to accompany

Scientific Investigations Map 3262

U.S. Department of the Interior

U.S. Geological Survey
Cover. Illustration showing simulated floods corresponding to a gage height of 3.0, 4.5, and 6.5 feet at the U.S. Geological Survey streamgage 

01390450 Saddle River at Upper Saddle River, New Jersey.
Flood-Inundation Maps for the Saddle River 

from Upper Saddle River Borough to Saddle 

River Borough, New Jersey, 2013

By Kara M. Watson and Heidi L. Hoppe

Prepared in cooperation with the 

New Jersey Department of Environmental Protection

Pamphlet to accompany

Scientific Investigations Map 3262

U.S. Department of the Interior

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

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation:

Watson, K. M., and Hoppe, H. L., 2013, Flood-inundation maps for the Saddle River from Upper Saddle River 

Borough to Saddle River Borough, New Jersey, 2013: U.S. Geological Survey Scientific Investigations Map 3262, 

8 p., 8 sheets, http://pubs.usgs.gov/sim/3262/.
iii

Acknowledgments

The authors wish to thank the many local, State, and Federal agencies that have cooperated in 

the funding for the operation and maintenance of the streamgage used for this study, especially 

the New Jersey Department of Environmental Protection and the U.S. Army Corps of Engineers, 

New York District. Special thanks are given to Natural and Technological Hazards Management 

Consulting, Inc. (NTHMC) for their cooperation in providing the hydrologic model for this study 

and to the National Weather Service for their continued support of the USGS flood-inundation 

mapping initiative.
iv

Contents

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

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

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

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

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

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

Constructing Water-Surface Profiles.........................................................................................................5

Hydrologic and Steady Flow Data......................................................................................................5

Topographic/Bathymetric Data ..........................................................................................................5

Energy Loss Factors .............................................................................................................................5

Model Calibration and Performance .................................................................................................5

Development of Water-Surface Profiles...........................................................................................6

Inundation Mapping ......................................................................................................................................6

Saddle River, New Jersey, Flood-Inundation Maps on the Internet............................................6

Disclaimer for Flood-Inundation Maps .............................................................................................6

Uncertainties and Limitations Regarding Use of Flood-Inundation Maps ..................................7

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

References Cited............................................................................................................................................7

Figures

1. Map showing location of study reach for the Saddle River in New Jersey.......................3

2. Map showing location of model extent and direction of surface-water flow 

at streamgage 01390450, Saddle River at Upper Saddle River, New Jersey......................4

Tables

1. U.S. Geological Survey streamgage and miscellaneous site information 

for study basin, Saddle River, New Jersey...............................................................................2

2. 1-percent annual exceedance probability peak-discharge estimates, 

drainage areas, and percentage of total discharge for selected locations 

on the Saddle River, New Jersey...............................................................................................5

3. Stages and water-surface elevations for the Saddle River at Upper Saddle River,

New Jersey streamgage with corresponding discharge estimates at Lake Street 

along the Saddle River, New Jersey, for selected simulated water-surface profiles ......6

4. Occurrence of bridge inundation determined from simulated water-surface 

profiles corresponding to a stage level for the study area extent 

for the Saddle River at Upper Saddle River, New Jersey, streamgage...............................7
v

Sheets

(Each sheet is available for download in PDF. For links, see http://pubs.usgs.gov/sim/3262/.)

1–8. Maps showing flood-inundation for the Saddle River from Upper Saddle River Borough 

to Saddle River Borough, New Jersey, corresponding to a gage height and an 

elevation (NAVD 88) as listed below at U.S. Geological Survey streamgage 01390450 

Saddle River at Upper Saddle River, New Jersey—

1. Gage height of 3.0 feet and an elevation of 187.2 feet.

2. Gage height of 3.5 feet and an elevation of 187.7 feet.

3. Gage height of 4.0 feet and an elevation of 188.2 feet.

4. Gage height of 4.5 feet and an elevation of 188.7 feet.

5. Gage height of 5.0 feet and an elevation of 189.2 feet.

6. Gage height of 5.5 feet and an elevation of 189.7 feet.

7. Gage height of 6.0 feet and an elevation of 190.2 feet.

8. Gage height of 6.5 feet and an elevation of 190.7 feet.
vi

Conversion Factors and Datums

Inch/Pound to SI

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).
Flood-Inundation Maps for the Saddle River from Upper 

Saddle River Borough to Saddle River Borough, 

New Jersey, 2013

By Kara M. Watson and Heidi L. Hoppe

Abstract

Digital flood-inundation maps for a 4.1-mile reach of the 

Saddle River from 0.6 miles downstream from the New JerseyNew York State boundary in Upper Saddle River Borough to 

0.2 miles downstream from the East Allendale Road bridge 

in Saddle River Borough, New Jersey, were created by the 

U.S. Geological Survey (USGS) in cooperation with the New 

Jersey Department of Environmental Protection (NJDEP). 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 and depth of flooding corresponding to select water 

levels (stages) at the USGS streamgage 01390450, Saddle 

River at Upper Saddle River, New Jersey. Current conditions 

for estimating near real-time areas of inundation using USGS 

streamgage information may be obtained on the Internet at 

http://waterdata.usgs.gov/nwis/uv?site_no=01390450. The 

National Weather Service (NWS) forecasts flood hydrographs at many places that are often collocated with USGS 

streamgages. NWS-forecasted peak-stage information may be 

used in conjunction with the maps developed in this study to 

show predicted areas of flood inundation. 

In this study, flood profiles were computed for the 

stream reach by means of a one-dimensional step-backwater 

model. The model was calibrated by using the most current 

stage-discharge relations (in effect March 2013) at USGS 

streamgage 01390450, Saddle River at Upper Saddle River, 

New Jersey, and documented high-water marks from recent 

floods. The hydraulic model was then used to determine eight 

water-surface profiles for flood stages at 0.5-foot (ft) intervals 

referenced to the streamgage datum, North American Vertical 

Datum of 1988 (NAVD 88), and ranging from bankfull, 0.5 ft 

below NWS Action Stage, to the upper extent of the stagedischarge rating which is approximately 1 ft higher than the 

highest recorded water level at the streamgage. Action Stage 

is the stage which when reached by a rising stream the NWS 

or a partner needs to take some type of mitigation action in 

preparation for possible significant hydrologic activity. The 

simulated water-surface profiles were then combined with 

a geographic information system 3-meter (9.84 ft) digital 

elevation model (derived from Light Detection and Ranging 

(LiDAR) data) in order to delineate the area flooded at each 

water level.

The availability of these maps along with real-time 

streamflow data and information regarding current stage from 

USGS streamgages and forecasted stream stages from the 

NWS 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 postflood recovery efforts.

Introduction

The Boroughs of Upper Saddle River and Saddle River 

are urban communities with estimated populations of 8,200 

and 3,150, respectively, and population densities of 1,560 and 

640 persons per square mile (U.S. Bureau of Census, 2010). 

These boroughs have experienced severe flooding numerous 

times, most notably in June and August 2011, Tropical Storm 

Floyd in 1999, and 1977. Damage costs for these floods (not 

adjusted for inflation) were reported to be $174,800 in 2011, 

$44,000 in 1999, and $22,380 in 1977 (New Jersey Department of Environmental Protection, State National Flood Insurance Program Coordinators Office, written commun., 2012). 

Most of the flood damages have occurred along the Saddle 

River, which flows through the Boroughs of Upper Saddle 

River and Saddle River. Floodplains within Upper Saddle 

River and Saddle River Boroughs are highly developed and 

contain a mix of residential and commercial structures.

Prior to this study, borough officials from Upper Saddle 

River and Saddle River have relied on several information 

sources (all of which are available on the Internet) to make 

decisions on how to best alert the public and mitigate flood 

damages. One source is the Federal Emergency Management 

Agency (FEMA) Flood Insurance Study (FIS) for Bergen 

County dated September 30, 2005 (Federal Emergency Management Agency, 2005). A second source of information is the 

USGS streamgage 01390450, Saddle River at Upper Saddle 

River, New Jersey, from which current or historical water 

levels (stage) can be obtained. A third source is the National 

Weather Service (NWS) forecast of peak stage at the USGS 

streamgage through the Advanced Hydrologic Prediction 
2 Flood-Inundation Maps for Saddle River from Upper Saddle River Borough to Saddle River Borough, New Jersey, 2013

Service (AHPS) Web site. Although information on USGS 

current stage and NWS forecast stage 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. Also, FEMA and State emergency management mitigation teams or property owners typically lack 

information related to how deep the water is at locations other 

than near USGS streamgage or NWS flood-forecast points.

Purpose and Scope

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

Saddle River from Upper Saddle River Borough to Saddle 

River Borough, New Jersey. The maps and other useful 

flood information are available on the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/

flood_inundation/. Internet users can select estimated inundation maps that correspond to (1) current stages at the USGS 

streamgage; (2) the NWS forecasted peak stage, or (3) other 

desired stream stages.

The scope of the study was limited to a 4.1-mile reach of 

the Saddle River from 0.6 miles downstream from the New 

Jersey-New York State boundary in Upper Saddle River Borough to 0.2 miles downstream from the East Allendale Road 

bridge in Saddle River Borough, New Jersey. Tasks specific 

to development of the maps were (1) analysis of peak streamflow data from station 01390450 (table 1), (2) collection of 

topographic data and geometric data (for structures/bridges) 

throughout the study reach, (3) verification of energy-loss 

factors (roughness coefficients) in the stream channel and 

floodplain, and steady-flow data from previous studies, (4) 

computation of water-surface profiles by use of the U.S. Army 

Corps of Engineer’s HEC–RAS computer program (U.S. 

Army Corps of Engineers, 2010) and a geographic information system (GIS), and (5) development of a Web interface that 

links to USGS real-time streamgage information and NWS 

forecasted peak stage to facilitate the display of user-selected 

flood-inundation maps on the Internet.

Methods used are generally cited from previously published reports. If techniques varied significantly from previously documented methods due to local hydrologic conditions 

or available data, they are described in detail in this report. 

Maps were produced for water levels referenced to the stage at 

USGS streamgage 01390450 and ranging from approximately 

bankfull, 0.5 ft below NWS Action Stage, to the upper extent 

of the stage-discharge rating, approximately 1 ft higher than 

the maximum observed water level at the streamgage. Action 

Stage is the stage which when reached by a rising stream, lake, 

or reservoir represents the level where the NWS or a partner/

user needs to take some type of mitigation action in preparation for possible significant hydrologic activity (National 

Weather Service, 2010).

Study Area Description

The Saddle River is in northeast New Jersey in the Piedmont physiographic province. The drainage area ranges from 

10.9 square miles (mi2) at USGS streamgage 01390450 to 

16.0 mi2 at the downstream extent of the study reach (fig. 1). 

The headwaters originate in Rockland County, in southern 

New York State, and the stream generally flows southward 

before entering the borough limits of Upper Saddle River in 

Bergen County, New Jersey. There are three major tributaries 

that flow into the Saddle River within the extent of the study 

reach. Pine Brook and West Branch Saddle River join the main 

stem of the Saddle River upstream from USGS streamgage 

01390450 as it flows through Upper Saddle River Borough 

(fig. 2). The third tributary, Pleasant Brook, joins the main 

stem of the Saddle River downstream from USGS streamgage 

01390450 as it flows through Upper Saddle River Borough. 

The headwaters of the Saddle River are 4.9 miles upstream 

from USGS streamgage 01390450. The Saddle River drains 

into the Passaic River 22.8 miles downstream from USGS 

streamgage 01390450. The basin terrain is moderately hilly. 

The study reach is approximately 4.1 miles long, has an average top-of-bank channel width of about 79 ft and an average 

channel slope of 52.1 feet per mile (ft/mi). About 81.1 percent 

of the land contiguous to the study reach is classified as urban 

or developed, 11.5 percent as forest, and 1.5 percent as wetland (New Jersey Department of Environmental Protection, 

2010). The basin is still under redevelopment, and population 

has increased 3.82 percent from 10,900 to 11,400 between 

2000 and 2010 [U.S. Census Bureau, 2012]. Six major road 

crossings or other structures are located within the channel of 

the study reach or the adjacent flood plain (fig. 2). 

Previous Studies

The current FIS for Upper Saddle River (Federal Emergency Management Agency, 2005) was completed by Natural 

and Technological Hazards Management Consulting, Inc. 

Table 1. U.S. Geological Survey streamgage and miscellaneous site information for study basin, Saddle River, New Jersey.

Station name Station 

number

Drainage area 

(square miles) Latitude Longitude Period of record

Maximum recorded 

stage at gage (feet) 

and date

Saddle River at Upper Saddle River, NJ 01390450 10.9 41°03ʹ31ʺ 74°05ʹ44ʺ Sept. 1966 to 

current year

5.64

Sep 16, 1999
Introduction 3

NEW YORK

NEW JERSEY

Passaic

River

Sa

ddle

River

BERGEN

PASSAIC

PASSAIC

ESSEX

ROCKLAND

01390450

01391000

01390500

01391500

74°15' 10' 5' 74°

41°05'

41°

40°55'

Base from U.S. Geological Survey 

1:24,000 scale digital data

Location of study 

area (shown in 

figure 2)

NEW YORK

NEW JERSEY

PENNSYLVANIA

DELAWARE

VALLEY AND

RIDGE

NEW ENGLAND

PIEDMONT

COASTAL PLAIN

EXPLANATION

Saddle River drainage 

basin boundary

State boundary

County boundary

U.S. Geological Survey 

streamgage and number 01391500

0 1 2 MILES

0 1 2 KILOMETERS

Figure 1. Location of study reach for the Saddle River in New Jersey. 
4 Flood-Inundation Maps for Saddle River from Upper Saddle River Borough to Saddle River Borough, New Jersey, 2013

EXPLANATION

Limit of study area

Flow arrow—Indicates

direction of water flow

Location of bridge

State boundary

Township boundary

U.S. Geological Survey 

streamgage and number

State route marker

01390450

17

Base from U.S. Geological Survey digital data and ESRI World Imagery File

North American Datum of 1983 (NAD 83)

Montvale 

Borough

Woodcliff 

Lake Borough

G A

R

D E N S T A T E P A R K W A Y

G A

R

D E N S T A T E P A R K W A Y

Saddle River 

Borough

Allendale

Borough

E A S T A L L E N D A L E R O A D

01390450

S a

d d l e

R i v e

r

Upper Saddle

River Borough

17

NEW YORK

NEW JERSEY

L A K E S T R E E T

U P P E R C R O S S R O A D

Pleasant

Brook

( F o o t b r i d g e )

0 0.5 1 MILE

0 0.5 1 KILOMETER

W

O L D S T O N E C H U R C H R O A D

es t Branch

Saddle

Ri ver

Pine B r o o k

B R O O K R O A D

74°07' 6' 5' 74°04'

41°04'

3'

41°02'

Figure 2. Location of model extent and direction of surface-water flow at streamgage 01390450, Saddle River at Upper Saddle River, 

New Jersey.
Constructing Water-Surface Profiles 5

(NTHMC) in 2004. That study provided information on the 

1- and 0.2-percent annual exceedance probability watersurface profiles and associated flood plain maps for the Saddle 

River. Estimates of the peak discharges for the 1-percent 

annual exceedance probability flood along the Saddle River, 

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

in FEMA (2005). 

Constructing Water-Surface Profiles

The water-surface profiles used to produce the eight 

flood-inundation maps in this study were computed by using 

HEC–RAS, version 4.1.0 (U.S. Army Corps of Engineers, 

2010). HEC–RAS is a one-dimensional step-backwater model 

for simulation of water-surface profiles with steady-state 

(gradually varied) or unsteady-state flow computation options. 

The HEC–RAS analysis for this study was done by using the 

steady-state flow computation option. An unsteady-state model 

would be more appropriate if the river had dynamic streamflow conditions such as backwater or tidal flow.

Hydrologic and Steady Flow Data

The study area hydrologic network consists of USGS 

streamgage 01390450 with a period of record from 1966 to the 

current water year (fig. 1; table 1). Water level (stage) is measured in real-time through a satellite radio transmitter continuously and continuous records of streamflow are computed at 

this site. All water-surface elevations are referenced to North 

American Vertical Datum of 1988 (NAVD 88) and displayed 

in the National Water Information System (NWIS). 

Steady-flow data consisted of flow regime, boundary 

conditions (normal depth, or the streamgage stage-discharge 

relation value), and peak-discharge information. The peakdischarge data for the study reach were obtained from field 

measurements and the stage-discharge relation (rating no. 7.0) 

that was developed by the USGS at streamgage 01390450.

Topographic/Bathymetric Data

Channel cross sections were developed from NTHMC 

field surveys that were conducted in 2004; these cross sections 

provide detailed channel elevation data below the water surface and were collected using hydroacoustic instrumentation 

to measure depth and Differential Global Positioning System 

(DGPS) instrumentation to determine horizontal position. 

Light Detection and Ranging (LiDAR) data were used to provide 3-meter (9.84 ft) digital elevation data for the portions of 

the cross sections that were above the water surface at the time 

of the surveys. The LiDAR data were collected in 2006–07, 

and post-processing of these data was completed by U.S. 

National Geospatial-Intelligence Agency (NGA) in 2007.

Various manmade drainage structures (bridges, culverts, 

roadway embankments, levees, and dams) in and along the 

stream affect or have the potential to affect water-surface 

elevations during floods along the stream. To properly account 

for six bridges (fig. 2) in the model, structural dimensions 

were measured and surveyed in the field concurrently with the 

stream-channel surveys. A detailed description of the methods 

used to acquire and process the topographic and bathymetric 

data can be found in Bales and others (2007). 

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 0.025 to 

0.035 for the main channel and 0.020 to 0.10 for the overbank 

areas modeled in this analysis. 

Model Calibration and Performance

The hydraulic model was calibrated to the most current 

stage-discharge relation at station 01390450. During the June 

2011 flood event, the measured peak discharge and associated stage were 3,790 cubic feet per second (ft3

/s) and 5.41 ft, 

respectively. The measured peak discharge and stage for the 

1999 flood were 6,290 ft3/s and 5.64 ft. Model calibration was 

accomplished by adjusting Manning’s n values and, in some 

cases, changing the channel cross section or slope until the 

results of the hydraulic computations closely agreed with the 

known flood discharge and stage values. Differences between 

measured and simulated water levels for measured or rated 

flows at USGS streamgage 01390450 were equal to or less 

than 0.22 ft. The results demonstrate that the model is capable 

of simulating accurate water levels over a wide range of flows 

in the basin. Details on techniques used in model development 

and calibration can be found in Bales and others (2007).

Table 2. 1-percent annual exceedance probability peak-discharge estimates, drainage areas, and percentage of total discharge for 

selected locations on the Saddle River, New Jersey. (from Federal Emergency Management Agency, 2005)

Location on Saddle River Drainage area 

(square miles)

Discharge estimate 

(cubic feet per second)

Percentage of 

total discharge

At Lake Street, Saddle River at Upper Saddle River, NJ streamgage 10.9 5,920 100
6 Flood-Inundation Maps for Saddle River from Upper Saddle River Borough to Saddle River Borough, New Jersey, 2013

Development of Water-Surface Profiles

Profiles were developed for a total of eight stages at 

0.5-ft intervals between 3.0 ft and 6.5 ft as referenced to 

USGS streamgage 01390450. Discharges corresponding to the 

various stages were obtained from the most current stagedischarge relation (rating no. 7.0) for station 01390450. 

Discharges for all profiles on the Saddle River (table 3) at 

locations upstream and downstream from USGS streamgage 

01390450 were selected with the assumption that the percentage contribution to the total flow was the same as that assumed 

for the 2005 FIS (table 2).

Inundation Mapping

Flood-inundation maps were created based on USGS 

streamgage 01390450, Saddle River at Upper Saddle River. 

The maps were created in a geographic information system 

by combining the water-surface profiles and digital elevation 

model data. The 3-meter (9.84-ft) digital elevation model data 

were derived from LiDAR data obtained from NGA (National 

Geospatial-Intelligence Agency, 2007). 

Each digitized cross-section line used for the study area 

was attributed with a HEC-RAS calculated water-surface 

elevation for each of the eight profiles (table 3). The flood 

surfaces were generated by using an iterative finite-difference 

interpolation technique found in the ArcGIS, TopoToRaster 

tool. This tool is unique because it is the only ArcGIS interpolation routine designed to work intelligently with contour 

data, and it combines locally efficient interpolation methods 

Table 3. Stages and water-surface elevations for the Saddle 

River at Upper Saddle River, New Jersey streamgage (U.S. 

Geological Survey streamgage 01390450) with corresponding 

discharge estimates at Lake Street along the Saddle River, 

New Jersey, for selected simulated water-surface profiles.

Profile 

number

Stage

(feet above 

gage datum)

Elevation

(feet above 

NAVD 88)

Discharge

(cubic feet 

per second)

1 3.00 187.2 182

2 3.50 187.7 330

3 4.00 188.2 550

4 4.50 188.7 1,250

5 5.00 189.2 2,550

6 5.50 189.7 4,110

7 6.00 190.2 6,300

8 6.50 190.7 9,290

with global surface-continuity routines (Environmental Systems Research Institute, Inc., 2009). Inputs into the tool are 

contour data using the digital cross sections attributed with 

the NAVD 88 elevation, in feet, and boundary data using the 

study-area polygon. Depth of water grids were generated by 

subtracting the flood water-surface elevation from the studyarea digital elevation model (DEM) (Roland and Hoffman, 

2011). The map products show estimated flood-inundated 

areas overlaid on high-resolution, geo-referenced, aerial 

photographs of the study area for each of the water-surface 

profiles that were generated by the hydraulic model.

Saddle River, New Jersey, Flood-Inundation 

Maps on the Internet

The flood-inundation maps and current study documentation are available online at the U.S. Geological Survey 

Publications Warehouse (http://pubs.usgs.gov/sim/2013/3262). 

Also, the Flood Inundation Mapping Science website has been 

established to provide a portal for USGS flood-inundation 

study information to the public at http://water.usgs.gov/osw/

flood_inundation/. The web portal has a link (http://wim.usgs.

gov/FIMI/FloodInundationMapper.html) to interactive online 

map libraries that can be downloaded in several commonly 

used electronic file formats. In the latter link, each stream 

reach displayed contains further links to the USGS National 

Water Information System (NWISWeb) graphs of the current 

stage and streamflow at USGS streamgage 01390450 to which 

the inundation maps are referenced. 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. Roadways and bridges were closely 

reviewed and are shown shaded (inundated and likely impassable) or not shaded (dry and passable) to facilitate emergency 

planning and use. Bridge surfaces that have a simulated water 

level surface at the low chord of the bridge deck or higher are 

depicted to be inundated (table 4). However, buildings which 

are shaded do not reflect inundation but denote that bare earth 

surfaces in the vicinity of the buildings are inundated. When 

the water depth (as indicated in the Web Mapping Application 

by holding the cursor over an inundated area) in the vicinity 

of the building of interest exceeds that building’s height, the 

structure can be considered fully submerged.

Disclaimer for Flood-Inundation Maps

Inundated areas shown should not be used for navigation, 

regulatory, permitting, or other legal purposes. 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.
References Cited 7

Table 4. Occurrence of bridge inundation determined from 

simulated water-surface profiles corresponding to a stage 

level for the study area extent for the Saddle River at Upper 

Saddle River, New Jersey, streamgage (U.S. Geological Survey 

streamgage 01390450).

Stage 

(feet) Bridge inundated

3.0 None

3.5 None

4.0 None

4.5 Upper Cross Road and Lake Street

5.0 East Allendale Road, Upper Cross Road, 

and Lake Street

5.5 East Allendale Road, Upper Cross Road, Lake 

Street, Stone Church Road, and Brook Road

6.0 East Allendale Road, Upper Cross Road, Lake 

Street, Stone Church Road, and Brook Road

6.5 East Allendale Road, footbridge, Upper Cross Road, 

Lake Street, Stone Church Road, and Brook Road

Uncertainties and Limitations Regarding Use of 

Flood-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 on the basis of water stages and streamflow 

at the USGS streamgage 01390450. Water-surface elevations along the stream reaches were estimated by steady-state 

hydraulic modeling, assuming unobstructed flow, and using 

streamflows and hydrologic conditions anticipated at the 

USGS streamgage. The hydraulic model reflects the landcover characteristics and any bridge, dam, levee, or other 

hydraulic structures existing as of September 2004. 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. Additional uncertainties and limitations pertinent to this study may be described 

elsewhere in this report.

If this series of flood-inundation maps will be used in 

conjunction with National Weather Service (NWS) river 

forecasts, the user should be aware of additional uncertainties 

that may be inherent or factored into NWS forecast procedures. The NWS uses forecast models to estimate the quantity 

and timing of water flowing through selected stream reaches 

in the United States. These forecast models (1) estimate the 

amount of runoff generated by precipitation and snowmelt, 

(2) simulate the movement of floodwater as it proceeds downstream, and (3) predict the flow and stage (and water-surface 

elevation) for the stream at a given location (AHPS forecast 

point) throughout the forecast period (every 6 hours and 3 to 

5 days out in many locations). For more information on AHPS 

forecasts, please see: http://water.weather.gov/ahps/pcpn_and_

river_forecasting.pdf. 

Summary

A series of estimated flood-inundation maps were 

developed in cooperation with the New Jersey Department of 

Environmental Protection for the Saddle River between the 

Borough of Upper Saddle River and the Borough of Saddle 

River, New Jersey. These maps, available at a U.S Geological 

Survey Web portal, in conjunction with the real-time stage 

data from the USGS streamgage 01390450, Saddle River 

at Upper Saddle River, New Jersey, will help to guide the 

general public in taking individual safety precautions and will 

provide municipal officials with a tool to efficiently manage 

emergency flood operations and flood mitigation efforts. 

The maps were developed by using the U.S. Army Corps 

of Engineers’ HEC–RAS and HEC–GeoRAS programs to 

compute water-surface profiles and to delineate estimated 

flood-inundation areas for selected stream stages. The maps 

show estimated (shaded) flood-inundation areas overlaid on 

high-resolution, geo-referenced, aerial photographs of the 

study area for stream stages between 3.0 ft and 6.5 ft at the 

USGS streamgage 01390450. Interactive use of the maps by 

using the mouse cursor to click within the shaded areas can 

give users a general indication of depth of water at any point. 

These maps can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/

flood_inundation/.

References Cited

Bales, J.D., Wagner, C.R., Tighe, K.C., and Terziotti, Silvia, 

2007, LiDAR-derived flood-inundation maps for realtime flood-mapping applications, Tar River Basin, North 

Carolina: U.S. Geological Survey Scientific Investigations 

Report 2007–5032, 42 p.

Environmental Systems Research Institute, Inc., 2009, Products—ArcGIS, accessed May 16, 2011, at http://www.esri.

com/products/index.html.
8 Flood-Inundation Maps for Saddle River from Upper Saddle River Borough to Saddle River Borough, New Jersey, 2013

Federal Emergency Management Agency, 2005, Flood Insurance Study, Bergen County, New Jersey: Washington, D.C., 

September 30, 2005, 4 p.

National Geospatial-Intelligence Agency, 2007, LiDAR-Metro 

N. Jersey 2006–07: Springfield, Virginia.

National Weather Service, 2010, National Weather Service 

Manual 10-950, accessed May 31, 2012, at http://www.nws. 

noaa.gov/directives/sym/pd01009050curr.pdf.

Natural and Technological Hazards Management Consulting, 

Inc., 2004, Final hydrology: Riverine flood insurance studies in FEMA Region II New Jersey FY-03, Saddle River, 

New Jersey, 107 p.

New Jersey Department of Environmental Protection, 2010, 

NJDEP 2007 Landuse/Landcover Update, State of New 

Jersey: Trenton, N.J.

Roland, M.A., and Hoffman, S.A., 2011, Development of 

flood-inundation maps for the West Branch Susquehanna 

River near the Borough of Jersey Shore, Lycoming County, 

Pennsylvania: U.S. Geological Survey Scientific Investigations Report 2010–5057, 9 p.

U.S. Army Corps of Engineers, Hydrologic Engineering 

Center, 2010, HEC–RAS River Analysis System, Hydraulic 

Reference Manual, version 4.1 [variously paged].

U.S. Bureau of Census, 2012, Census 2010 State and county 

quick facts, accessed April 23, 2012, at http://quickfacts.

census.gov/qfd/states/34/3441100.html.
For additional information contact:

Director, Indiana Water Science Center

5957 Lakeside Blvd.

Indianapolis, IN 46278

http://in.water.usgs.gov/

Publishing support provided by: West Trenton Publishing Service Center
Watson and Hoppe—Flood-Inundation Maps for the Saddle River from Upper Saddle River Borough to Saddle River Borough, New Jersey, 2013—Scientific Investigations Map 3262