Wildlife and Wildlife Habitat Loss Assessment at Dexter Dam and Reservoir Project, Middle Fork Willamette River, Oregon, 1985 Final Report.

Abstract

A habitat based assessment was conducted of the US Army Corps of Engineers' Dexter Dam and Reservoir Project on the Middle Fork Willamette River, Oregon, to determine losses or gains resulting from the development and operation of the project. Preconstruction, post-construction, and recent vegetation cover types of the project site were mapped based on aerial photographs from 1944, 1956, 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 Dexter Project extensively altered or affected 4662 acres of land and river in the Middle Fork Willamette River drainage. Impacts to wildlife centered around the loss of 445 acres of riparian habitat. Impacts resulting from the Dexter Project included the loss of year-round habitat for black-tailed deer, red fox, mink, beaver, western gray squirrel, ruffed grouse, ring-necked pheasant, Californiamore » quail, wood duck and nongame species. Bald eagle, osprey, and greater scaup were benefitted by an increase in foraging habitat. The potential of the affected area to support wildlife was greatly altered as a result of the Dexter Project. Losses or gains in the potential of the habitat to support wildlife will exist over the life of the project.« less