Introduction

Due to Idaho’s inland location approximately 350 miles from the Pacific Ocean and its 80 recognized mountain ranges, the State’s climate varies widely, with maritime influence in the northern and western parts of Idaho and continental influence on the eastern side. The weather in the abundant mountains is unpredictable and often associated with natural hazards such as severe thunder and lightning storms leading to flooding, landslides, and wildfires. Issues important to Idaho’s economy include river, stream, and forest resource management, and infrastructure and construction management. Idaho participated in the U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) in 2016, the State’s first 3DEP project. The success of this project led to development of the Idaho Statewide Lidar Plan (Elevation Technical Working Group and Idaho Lidar Consortium, 2018). Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features.

The 3D Elevation Program (see sidebar) is managed by the U.S. Geological Survey in partnership with Federal, State, Tribal, U.S. territorial, and local agencies to acquire consistent lidar coverage at quality level 2 or better (table 1) to meet the many needs of the Nation and Idaho. The status of available and in-progress 3DEP baseline lidar data in Idaho is shown in figure 1. 3DEP baseline lidar data include quality level 2 or better, 1-meter or better digital elevation models, and lidar point clouds, and must meet the Lidar Base Specification version 1.2 (https://www.usgs.gov/3dep/lidarspec) or newer requirements. The National Enhanced Elevation Assessment (Dewberry, 2012) identified user requirements and conservatively estimated availability of lidar data would result in at least $6.12 million in new benefits annually to the State. The top eight Idaho business uses for 3D elevation data, which are based on the estimated annual conservative benefits of 3DEP, are shown in table 2.

Status of 3DEP in Idaho

3DEP quality level 1 lidar collections are being planned for parts of central and southern Idaho. These plans would most likely take place during the 2023 collection cycle. Subsequent collections would take place along the Idaho-Montana border in parts of central and northern Idaho during the 2024 cycle.

River and Stream Resource Management

The river and stream resource management business use is associated with ensuring the Nation’s rivers and streams sustain economic, recreational, and subsistence activities and their other beneficial functions. Lidar data improve the results of related activities such as hydrologic and hydraulic modeling of rivers and streams, mapping of flood plains, ecosystem management, establishment of accurate stream buffers, and enabling stormwater quality management (fig. 2). In addition, lidar data enable identification of stream restoration opportunities, provide critical information on stream health, and help cities and counties accurately assess developer plans for controlling stormwater runoff in new residential and commercial developments. Overall, lidar data help governments to be more efficient and effective in managing the State’s rivers and streams while providing added cost savings to the public.

Flood Risk Management

The Idaho Department of Water Resources (IDWR) utilizes lidar to determine drain elevations for groundwater modeling and for both flood hazard mapping and flood investigations. IDWR’s Water Resource Board has been using lidar for the assessment of water infrastructure projects. Ada County Emergency Management (ACEM) supports the acquisition of lidar data as part of its Multi-Hazard Mitigation Plan for flooding, wildfires, and landslide risks. As part of this effort, ACEM has utilized bathymetric lidar for flood modeling the Boise River, creating maps used for public outreach, and emergency response planning.

Wildfire Management, Planning, and Response

The Idaho Department of Lands (IDL) manages Idaho’s State Trust Lands and provides regulatory oversight of forestry practices and some regulation of mining practices on State lands. The IDL also administers forestry programs and provides fire protection on State lands. According to Geoff Klein, IDL program manager, written commun., May 5, 2019, “IDL has been collecting and utilizing lidar across state endowment lands since 2015 to assist state foresters in decision making. IDL utilizes lidar for forest road engineering design to access areas for timber harvesting. They also use lidar point clouds for developing forest canopy height models and to assist with models of stand volume and other inventory metrics.”

Geologic Resource Assessment and Hazard Mitigation

Geologic mapping, including the assessment of mineral deposits and geologic hazards, can be performed more efficiently and accurately using lidar data and provides significant cost savings by reducing the need for in-field investigations. The geologic maps produced by the Idaho Geological Survey provide a base for further geologic exploration and depict faults, folds, landslides, and cross sections of geologic units.

The value of Idaho mineral extraction was $185 million in 2019 (U.S. Geological Survey, 2020). Gemstone-quality garnet, jasper, and opal are found in Idaho, and contribute to the mineral extraction economy.