Layer: Elevation Restriction
This layer represents elevation restrictions for exploration and development of geothermal resources in Washington State. High elevations can be restrictive to development due to logistical and climatic conditions, especially in the Cascade Range, where annual snowfall can exceed 1,000 in. at elevations as low as 4,200 ft. Most high-elevation areas are also remote, have little existing infrastructure, and may be inaccessible during several months of the year. Many areas thought to have high heat flow, such as Mount St. Helens volcano, a “Known Geothermal Resource Area” (KGRA), are at high elevations, making these areas challenging for geothermal resource development. While extreme elevation and climate do not necessarily preclude development of geothermal resources, the model assumes favorability will decline with increasing elevation above 5,000 ft, and elevations above 8,000 ft will prohibit any development activity.
Elevation restrictions occur predominantly in the Cascade Range, with maximum restriction limited primarily to major stratovolcanoes and distributed highlands in the North Cascades. There are also regions of varying elevation restriction in the Olympic Mountains, Blue Mountains, and Okanogan Highlands, with additional isolated areas along the western margin of the Columbia Basin.
The data was derived from USGS 10-m DEMs (Digital Elevation Models) and resampled to a 500-foot grid size for inclusion in the Geothermal Favorability Model of Washington State. See the companion report (Boschmann and others, 2014) for detailed discussion of modeling and results. The raster dataset is also available in the downloadable data file [elevation_restrictions] within the file geodatabase [geothermal_favorability.gdb].
Boschmann, Darrick E.; Czajkowski, J. L.; Bowman, J. D., 2014, Geothermal favorability model of Washington State: Washington Division of Geology and Earth Resources Open File Report OFR 2014-02, 26 p., 1 plate, scale 1:900,000. [http://www.dnr.wa.gov/publications/ger_ofr2014-02_geothermal_favorability.pdf]
Boschmann, D. E.; Czajkowski, J. L.; Bowman, J. D., 2014, Washington State geothermal favorability model database—GIS data: Washington Division of Geology and Earth Resources Digital Data Series 9, version 1.0.