A Simplified Method for Estimating Habitat Output for the Riverview Park Side Channel Restoration, Kent, Washington

This paper discusses the development and application of a simplified method to compare the relative habitat output expected from various side channel restoration alternatives. The analysis compared various side-channel alternatives characterized by either a seasonal or perennial flow condition. The channel alternatives included a trapezoidal rock channel, a rock channel with wood debris benches, a trapezoidal section with bio-engineered banks, and bio-engineered configurations with either 3 ft or 5 ft (0.9 m or 1.5 m) high "benches" at the bank toe. Though not critical to habitat outcomes, project alternatives also considered long-span, short-span, and at-grade side rock weir channel crossings. For this evaluation, potential habitat value was measured by estimating effective habitat units (EHU), which were a function of habitat area, inundation probability, and habitat quality.