An environmental overview of the Cat Arm hydroelectric development

The Cat Arm Dam hydroelectric development in Newfoundland comprises 10 dams, three tunnels, two canals and a 127 MW powerhouse. The scheme develops 127 MW from 380.5 m of head and comprises: ten dams of varying heights up to 53 m; a bathtub type overflow spillway 330 m in length; a 230 m long inverted U-shaped diversion tunnel; an 800 m long, inverted U-shaped low pressure forebay tunnel; two bog and rock cut tunnels leading to and from the forebay tunnels; a surface powerhouse containing two Pelton turbines; and a 178 km long, 230 kV transmission line. An overview is provided of the environmental assessment, project impacts, and cost of environmental protection associated with the project. Impacts were centered around fish and aquatic life in the created reservoir and downstream of the powerhouse, loss of ungulate (moose and caribou) habitat due to flooding, loss of forestry resources due to flooding, and the disturbance of land during construction. The overall cost of environmental protection was $7,977,000, only 2% of the total project cost. 17 refs., 1 tab