Wildlife and Wildlife Habitat Loss Assessment at Cougar Dam and Reservoir Project, South Fork McKenzie River, Oregon; 1985 Final Report.

Abstract

A habitat based assessment was conducted of the US Army Corps of Engineers' Cougar Dam and Reservoir Project on the South Fork McKenzie River, Oregon, to determine losses or gains resulting from the development and operation of the hydroelectric related components of the project. Preconstruction, postconstruction, and recent vegetation cover types of the project site were mapped based on aerial photographs from 1953, 1965, and 1979, respectively. Vegetation cover types were identified within the affected area and acreages of each type at each period were determined. Fifteen wildlife target species were selected to represent a cross-section of species groups affected by the project. An interagency team evaluated the suitability of the habitat to support the target species at each time period. An evaluation procedure which accounted for both the quantity and quality of habitat was used to aid in assessing impacts resulting from the project. The Cougar Project extensively altered or affected 3096 acres of land and river in the McKenzie River drainage. Impacts to wildlife centered around the loss of 1587 acres of old-growth conifer forest and 195 acres of riparian hardwoods. Impacts resulting from the Cougar Project included the loss of winter range for Roosevelt elk, and the loss of year-round habitat for black-tailed deer, black bear, cougar, river otter, beaver, spotted owl, and other nongame species. Bald eagle and osprey were benefited by an increase in foraging habitat. The potential of the effected area to support wildlife was greatly altered as a result of the Cougar Project. Loses or grains in the potential of the habitat to support wildlife will exist over the life of the project.