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Testimony of Steve Feldgus Senior Science Advisor Principal Deputy Assistant Secretary for Land and Minerals Management U.S. Department of the Interior

January 31, 2024

Before Energy and Mineral Resources Subcommittee House Committee on Natural Resources U.S. House of Representatives Washington D.C. on 3DEP-Landslides Reauthorization.


The U.S. Geological Survey (USGS) is a science bureau within the U.S. Department of the Interior (DOI). The USGS provides science about the natural hazards that threaten lives and livelihoods; the water, energy, mineral, and other natural resources we rely on; the health of our ecosystems and environment; and the impacts of climate and land-use change. Our scientists develop new methods and tools to enable timely, relevant, and useful information about the Earth and its processes.

Landslides hazards occur in every U.S. State and most Territories affecting lives, property, infrastructure, and the environment. Widespread or severe landslide events are often driven by other hazards such as hurricanes, earthquakes, volcanic eruptions, atmospheric rivers, and wildfire. Landslides can also cause cascading consequences, such as the spread of hazardous materials or the generation of devastating local tsunami. The USGS has mapped and conducted studies on landslides since its inception and is home to the only Federal program dedicated to landslide-hazard science. Nonetheless, more than 10 different Federal agencies and offices, such as the U.S. Army, Department of Commerce, Department of Homeland Security, Department of Transportation, National Science Foundation, Office of Science and Technology Policy, Office of Management and Budget, for example, have some stake in landslide-hazard mitigation, response, and recovery. 

The 2021 National Landslide Preparedness Act (NLPA) (P.L. 116-323) directs the DOI to create a program to: identify and understand landslide hazards and risks; reduce losses from landslides; protect communities at risk from landslides; and help improve communication and emergency preparedness for landslide disasters and impacts. In 2022, the USGS published a new National Strategy for Landslide Loss Reduction1 which describes four goals – Assess, Coordinate, Plan, and Respond to landslide hazards – and a set of strategic actions for each. Achieving the four goals will better protect lives, livelihoods, and natural and cultural resources from landslide hazards and lead to a more resilient Nation. 

Under the Act, the USGS has established the Interagency Coordinating Committee on Landslide Hazards (ICCLH) which first met in early 2023 and is soliciting nominations to the Federal Advisory Committee on Landslides. The USGS is also establishing a new external assistance program to support landslide hazard data collection and risk communication activities by governmental partners directed by its FY 2023 appropriation. Coordination with the National Weather Service to expand the partnership to deliver and improve debris-flow alerts for recently burned areas is ongoing. The USGS is currently providing hazard assessments upon request for wildfires anywhere in the Nation and is working with State, academic, and other partners to collect the data needed to reduce the uncertainty of debris-flow alerting criteria in the Pacific Northwest and other regions. 

Landslides assessments, investigations, technical assistance in support of emergency response and outreach all depend on a detailed and accurate understanding of the landscape.  Section 5 of the NLPA authorizes the 3D Elevation Program (3DEP), which is managed by the USGS National Geospatial Program, to respond to the growing need for high-quality topographic data and for a wide range of other three-dimensional (3D) representations of the Nation’s natural and constructed features. At the end of Fiscal Year (FY) 2023, 3DEP elevation data were available or in progress for about 94 percent of the Nation. Based on an extensive study of user needs and benefits, the USGS is designing a plan for the next generation of 3DEP with a shorter collection cycle and repeat coverages of higher-quality elevation data for the U.S. and its territories. The new data, when compared to the baseline 3DEP data, will significantly expand analytic capabilities and support assessments of landscape change due to landslides as well as other drivers including construction, lava flows, surface mining, sinkholes, and shoreline erosion.

The National Landslide Preparedness Act of 2021 established the 3D Elevation Federal Interagency Coordinating Committee (3DE-FICC) to coordinate 3D-elevation data management across the Federal Government and provided executive guidance on the strategy and implementation of 3DEP. The 3DE-FICC is being established by the DOI Assistant Secretary for Water and Science during FY 2024.  The law further established a DOI 3DEP Subcommittee under the Federal Geographic Data Committee's National Geospatial Advisory Committee to provide a 3DEP assessment and recommendations to the 3DE-FICC. The Subcommittee represents non-federal interests as required by statute and was established in August 2022. The Subcommittee’s assessment of 3DEP was published in June 2023, and included a series of recommendations on the future direction of the program. The Subcommittee issued a resolution in October 2023 endorsing the design for the next generation of 3DEP described in the draft “The 3D National Topography Model Call for Action Part 2: Next Generation of the 3D Elevation Program.



The USGS appreciates the introduction of a reauthorization of the NLPA. The USGS would like Congress to consider additional substantive amendments to the text of the NLPA statute which would improve our ability to implement this vital authority along with our partners.

In Section 3, authorizing the National Landslide Hazards Reduction Program, some of the language could go beyond USGS and DOI mandates. Paragraphs (a)(3) and (b)(1)(C)(ii) could be interpreted as directing the USGS and DOI to direct emergency-management and land-use decisions that are more appropriately made by State, Tribal, and local governments. We want to work with the Committee to develop alternatives to ensure that USGS science is available to local authorities without the unintended implications of interfering with their responsibilities. 

Paragraph (b)(3) authorizes a database of landslide mapping; however, without private insurance industry incentives to collect it, data on the impacts of landslides and practices to stabilize and reduce losses from landslides are not available. Additional academic and private-sector research on the development of this database is a prerequisite to effectively implement a program for collecting such data. In paragraph (b)(4), the USGS is authorized to develop guidance, tools, and other products intended for use by State, Tribal, and local authorities to support landslide-hazard risk reduction. This is a laudable vision for a fully realized program, and current activities can make it possible. However, the USGS and DOI will need to work with Congress to identify the resources required to implement this vision in future budgets. 

In paragraph (c)(2), the National Aeronautics and Space Administration should be added as a participant in the interagency committee. In paragraph (e), regarding grants, the USGS already has the authority to enter into cooperative agreements with partners, a more flexible tool than a grant. Specifically, the 50 percent cost match at (e)(1)(A)(ii)(III) is prohibitive for some potential partners. Moreover, the biennial report required in paragraph (f) should be extended to a four-year requirement to reduce administrative burden. Lastly, in paragraph (b)(5) authorizing the Debris Flow Early Warning System, we recommend replacing “stormwater drainage” with “rainfall and soil-moisture conditions,” which are the more technically correct criteria used in the system.

In Section 5 authorizing 3DEP, the USGS recommends several changes to better reflect the current state of the program’s implementation and the ongoing need for data collection. In paragraph (a)(1)(A), we recommend adding the word “recurring” before “3D elevation,” and in paragraphs (a)(1), (a)(2)(B), (b)(1), (c)(2)(A), and (d)(1) adding the term “multi-temporal” before each instance of “3D elevation data.” Together, these additions will reinforce the need to collect future 3DEP data to maintain quality and identify changes in the landscape, which are essential criteria for landslide-hazard research. In paragraphs (a)(1)(A) and (a)(1)(C), we recommend changing “3D elevation data” to “3D elevation and derivative data;” in paragraph (a)(2)(B)(i), we recommend striking “process and integrate.” These two technical changes will better reflect the lifecycle of 3DEP data. Lastly, in paragraph (b)(3), we recommend adding the 3D Hydrography Program Working Group to the list of entities the interagency committee will coordinate with. 3D hydrography is the next innovation in USGS mapping of streams and watersheds, and it is derivative of 3DEP data.

The USGS welcomes the chance to collaborate with the Committee in addressing these concerns. The research, as sanctioned by the NLPA, represents a significant contribution to landslide hazards science.


1 OFR 2022-1075