DOI: 10.5066/p13vdsrg
title: High-resolution orthoimagery and digital surface model of Cottage Grove Lake, Oregon, December 2023

description: In cooperation with the U.S. Army Corps of Engineers (USACE), the U.S. Geological Survey (USGS) surveyed ground control points and coordinated aerial photograph acquisition of Cottage Grove Lake, a multi-purpose reservoir in western Oregon impounded by the 29-meter ([m]; 95-foot [ft]) tall Cottage Grove Dam. Aerial photographs were acquired by the Civil Air Patrol (CAP) in December 2023 when water levels were at or near typical annual “low pool” or minimum pool, a target elevation (229 m/751 ft National Geodetic Vertical Datum of 1929 [NGVD 29]) for flood risk management operations. Photographs were acquired at a single altitude with a WaldoAir XCAM Ultra 50 camera mounted on a Cessna aircraft and captured the entire reservoir area as defined by full pool (or maximum conservation pool elevation), including the major tributary entering the reservoir, the Coast Fork Willamette River. Dam operations at the 468-hectare (1156-acre) Cottage Grove Lake, located about 15 kilometers upstream of the confluence of the Coast Fork Willamette River and the Willamette River, along with other hydrogeomorphic conditions, result in a diverse array of geomorphic processes and landforms within the reservoir. To document reservoir floor geomorphology, the USGS applied structure-from-motion (SfM) techniques to these aerial photographs, following the workflow outlined in Over and others (2021) and used for similar datasets (Schwid and others, 2025), and generated a three-dimensional xyz point cloud, digital surface model (DSM), and orthomosaic of Cottage Grove Lake.
 
This data release includes ground control points, dataset footprints, original aerial photographs, a point cloud, a DSM, and an orthomosaic of Cottage Grove Lake that were developed from imagery acquired on December 18, 2023. The point cloud has an average point density of 7.47 points per square meter, the DSM resolution is 36.6 centimeters per pixel, and the orthomosaic ground resolution is 9.15 centimeters per pixel. The DSM and orthomosaic are formatted as Cloud Optimized GeoTIFFs (COGs) for enhanced web visualization (GDAL, 2024).
 
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