3DEP in Illinois by the Numbers

Expected annual benefits $85.44 million 

Estimated total cost $18.82 million

Payback 0.2 years

Quality level 1 buy-up 

estimate

$11.98 million

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2014–3086

September 2014

The 3D Elevation Program—Summary for Illinois

Introduction

Elevation data are essential to a broad 

range of applications, including forest 

resources management, wildlife and habitat 

management, national security, recreation, and 

many others. For the State of Illinois, elevation 

data are critical for flood risk management, 

water supply and quality, infrastructure and 

construction management, agriculture and precision farming, and other business uses. Today, 

high-density light detection and ranging (lidar) 

data are the primary sources for deriving elevation models and other datasets. Federal, State, 

and local agencies work in partnership to (1) 

replace data that are older and of lower quality 

and (2) provide coverage where publicly accessible data do not exist. A joint goal of State 

and Federal partners is to acquire consistent, 

statewide coverage to support existing and 

emerging applications enabled by lidar data. 

The National Enhanced Elevation 

Assessment (NEEA; Dewberry, 2011) evaluated multiple elevation data acquisition options 

to determine the optimal data quality and data 

replacement cycle relative to cost to meet the 

identified requirements of the user community. The evaluation demonstrated that lidar 

acquisition at quality level 2 (table 1) for the 

conterminous United States and quality level 5 

interferometric synthetic aperture radar (ifsar) 

data (table 1) for Alaska with a 6- to 10-year 

acquisition cycle provided the highest benefit/

cost ratios. The 3D Elevation Program (3DEP) 

initiative (Snyder, 2012a,b) selected an 8-year 

acquisition cycle for the respective quality 

levels. 3DEP, managed by the U.S. Geological 

Survey (USGS), the Office of Management 

and Budget Circular A–16 lead agency for terrestrial elevation data, responds to the growing 

need for high-quality topographic data and a 

wide range of other 3D representations of the 

Nation’s natural and constructed features.

3D Elevation Program Benefits 

for Illinois

The top 10 Illinois business uses for 

3D elevation data, which are based on the 

estimated annual conservative benefits of 

the 3DEP initiative, are shown in table 2. 

The NEEA survey respondents in the State 

of Illinois estimated that the national 3DEP 

initiative would result in at least $85.4 million 

in new benefits annually to the State. The cost 

for such a program in Illinois is approximately 

$19 million, resulting in a payback period of 

0.2 years and a benefit/cost ratio of 36.3 to 

1 over an 8-year period. Because monetary 

estimates were not provided for all reported 

benefits, the total benefits of the 3DEP to 

Illinois are likely much higher. 

Approximately 83 percent of the 

identified business use requirements will be 

met in flood risk management, water supply 

and quality, and infrastructure and construction management uses, as shown in table 2. 

However, since providing information for 

the NEEA survey, Illinois agencies using 

lidar-based analyses have identified increased 

benefits for agriculture and precision farming, 

natural resources conservation, and geologic 

resource assessment and hazard mitigation 

business uses. The status of publicly available 

lidar data in Illinois is shown in figure 1. By 

enhancing coordination between 3DEP and 

various government and private organizations 

in Illinois, it is expected that benefits will be 

realized for additional business uses.

 The following examples highlight 

how 3DEP data can support business uses 

in Illinois: (1) The Illinois Department of 

Transportation began acquiring lidar data on 

a systematic basis in 2008, resulting in time 

savings for hydraulic surveys, as well as more 

3D Elevation Program

3DEP is a national program managed 

by the USGS to acquire high-resolution 

elevation data. The initiative is backed by 

a comprehensive assessment of requirements (Dewberry, 2011) and is in the 

early stages of implementation. 3DEP will 

improve data accuracy and provide more 

current data than is available in the National 

Elevation Dataset (NED). The goal of this 

high-priority cooperative program is to be 

operational by January 2015, and to have 

complete coverage of the United States 

by the end of 2022, depending on funding 

and partnerships. 3DEP can conservatively 

provide new benefits of $1.2 billion/year 

and has the potential to generate $13 billion/year in new benefits through improved 

government services, reductions in crop 

and homeowner losses resulting from 

floods, more efficient routing of vehicles, 

and a host of other government, corporate, 

and citizen activities (Dewberry, 2011). A 

shared, common elevation dataset would 

foster cooperation and improve decisionmaking among all levels of government and 

other stakeholders.

Benefits of a Funded National Program

• Economy of scale—Acquisition of 

data covering larger areas reduces 

costs by 25 percent.

• A systematic plan—Acquisition of 

data at a higher quality level reduces 

the cost of “buying up” to the highest levels needed by State and local 

governments.

• Higher quality data and national 

coverage—Ensure consistency for 

applications that span State and watershed boundaries and meet more needs, 

which results in increased benefits 

to citizens.

• Increase in Federal agency contributions—Reduces State and local partner 

contributions.

• Acquisition assistance—Provided 

through readily available contracts and 

published acquisition specifications.

Figure 1. Map of Illinois showing the 

extent of existing and planned publicly 

available lidar data. Information source: 

United States Interagency Elevation 

Inventory, June 2014, updated annually. 

Quality level 2 or better lidar data meet 

3DEP requirements. See table 1 for quality 

level information. 

EXPLANATION

Quality level 2

or better data

Quality level 3

data

Quality level 4

or lower data

No publicly available

lidar data

0 50 Kilometers

0 40 Miles
Next Steps for Implementing 3DEP

Accomplishing the 3DEP initiative’s 

goal of national coverage in 8 years depends 

on the following factors:

• Increased partnerships among Federal, 

State, Tribal, and local governments. 

• Partnerships that acquire elevation data 

to the program’s specifications across 

larger project areas.

• Increased communication about and 

awareness of the program’s benefits 

and goals.

• Support for the program from government and other stakeholders.

For Further Information:

Director, 

USGS National Geospatial Program

12201 Sunrise Valley Drive, MS 511

Reston, VA 20192

Email: 3DEP@usgs.gov

Shelley Silch, 

 USGS Geospatial Liaison

1201 West University Avenue

Suite 100, MS 309

Urbana, IL 61801

Email: ssilch@usgs.gov

http://nationalmap.gov/3DEP/

By William J. Carswell, Jr.

precise locations for previously unidentified 

river and watershed hydraulic problems. (2) As 

significantly more data have become available since 2008, lidar has developed into an 

important tool in geologic mapping of the State 

and identifying geologic hazards. For example, 

a lidar digital terrain (bare earth) model was 

used by the Illinois State Geological Survey 

to identify and inventory karst sinkholes 

within Monroe County, in southwestern 

Illinois (fig. 2A). It is estimated that Monroe 

County contains more than 10,000 sinkholes 

and has the highest concentration of karst 

features within the State, making groundwater 

contamination and ground failures potential 

hazards. A lidar digital surface model (fig. 2B) 

of the same area shows how dense woodland 

obscures the detection and delineation of the 

sinkhole features. 

References Cited

Dewberry, 2011, Final report of the National 

Enhanced Elevation Assessment (revised 

2012): Fairfax, Va., Dewberry, 84 p. 

plus appendixes, http://www.dewberry.

com/Consultants/GeospatialMapping/

FinalReport-NationalEnhancedElevation

Assessment.

Snyder, G.I., 2012a, National Enhanced 

Elevation Assessment at a glance: U.S. 

Geological Survey Fact Sheet 2012–3088, 

2 p., http://pubs.usgs.gov/fs/2012/3088/.

Snyder, G.I., 2012b, The 3D Elevation Program—Summary of program 

direction: U.S. Geological Survey 

Fact Sheet 2012–3089, 2 p., http://

pubs.usgs.gov/fs/2012/3089/.

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20143086

3D Elevation Program—Continued

The USGS and its partners will 

acquire quality level 2 or better (table 1) 

3D lidar data over the conterminous United 

States, Hawaii, and the U.S. territories. 

Interferometric synthetic aperture radar 

(ifsar) data are being collected at quality 

level 5 (table 1) in Alaska. The data will 

be acquired over an 8-year period and will 

be made available to the public. By using 

this acquisition scenario, a number of 

high-quality elevation-data products can be 

created to serve a wide range of business 

uses in government and the private sector.

Figure 2. A lidar digital terrain model (bare earth) for an area of 44 acres shows sinkholes 

(A) in Monroe County, Illinois, a region underlain by highly erodible limestone, which is highly 

susceptible to sinkhole creation. A lidar digital surface model of the same area (B) shows 

aboveground features such as vegetation and structures. Several single-family houses are 

in close proximity to deep sinkhole features that are hidden by dense woodland vegetation. 

Courtesy of Illinois State Geological Survey. 

A B

Table 2. Conservative benefits estimates for the top 10 business uses of the 

proposed 3DEP data identified in the National Enhanced Elevation Assessment for 

Illinois (Dewberry, 2011). In 2014, Illinois agencies identified increased benefits for 

agriculture and precision farming, natural resources conservation, and geologic 

resource assessment and hazard mitigation business uses.

Rank Business use Annual benefits

(millions)

1 Flood risk management $32.40

2 Water supply and quality 21.76

3 Infrastructure and construction management 16.61

4 Agriculture and precision farming 8.18

5 Homeland security, law enforcement, and disaster response 3.21

6 Natural resources conservation 2.47

7 Geologic resource assessment and hazard mitigation 0.28

8 Wildlife and habitat management 0.16

9 Aviation navigation and safety 0.12

10 Urban and regional planning 0.09

Other 0.16

Total 85.44

Table 1. Data quality levels and related 

accuracies for the 3D Elevation Program 

(3DEP) initiative. These data quality 

parameters for the 3DEP initiative approximate 

those used in the National Enhanced Elevation 

Assessment (Dewberry, 2011).

[RMSE(z), root mean square error in the z 

(elevation) dimension; n/a, not applicable]

Quality 

level

Nominal pulse 

spacing

(meters)

Vertical error 

as RMSE(z)

(centimeters)

1 0.35 10

2 0.7 10

3 2.0 20

4 n/a 139

5 n/a 185