Designing Alaska: Building Sustainable Ecosystem Services Into Stream Mitigation

Mitigation designs that consider and make allowances for the resumption of ecological function are better suited for the purposes of fish habitat mitigation than projects that only consider the physical and morphological aspects of habitat. Environmental Resources Management (ERM) is working with a client to permit and develop a surface coal mine. Mining activities, which will result in temporary removal of several miles of salmon stream channel and adjacent floodplain habitat in a phased approach over the life of the operation, represent an integrated water management challenge unlike any other to date. The impacted stream contains both iconic salmon species (Chinook and coho) and non-migratory resident species (Dolly Varden and rainbow trout). The project reaches are in remote and wild areas so we propose that project restoration performance standards be developed based on natural observed pre-mining channel and flood plain functions. Mitigation plans will replace some of the physical habitats and over time these will become part of the natural landscape and assume some of the ecological functions and services provided by pre-mine habitat. This requires balancing short term project designs, including bank armoring (prior to vegetative establishment), with long term goals of restoring natural channel function and the ecosystem services it provides for fish habitat.