ECOSYSTEM RESTORATION - A CASE-STUDY IN THE OWENS RIVER GORGE, CALIFORNIA

In 1991 the Los Angeles Department of Water and Power, in cooperation with Mono County, California, initiated a multiyear effort to restore the Owens River Gorge. The project aims to return the river channel, d ewatered for more than 50 years, to a functional riverine-riparian eco system capable of supporting healthy brown trout and wildlife populati ons. The passive, or natural, restoration approach focused on the deve lopment of riparian habitat and channel complexity using incremental i ncreases in pulse (freshet) and base flows. Increasing pulse and base flows resulted in establishment and rapid growth of riparian vegetatio n on all landforms, and the formation of good-quality microhabitat fea tures (pools, runs, depth, and wetted width). An extremely complex, pr oductive habitat now occupies the bottom lands of the Owens River Gorg e. A healthy fishery in good condition has quickly developed in respon se to habitat improvement. Brown trout numbers have increased each yea r since initial stocking, 40% between 1996 and 1997. Catch rates incre ased from 0 fish/hr in 1991 to 5.8-7.1 fish/hr (with a maximum catch r ate of 15.7 fish/hr) in 1996. Restoring the Owens River Gorge bridges the theoretical concepts developed by Kauffman et al. (1997) and the p ractical application of those concepts in a real-time restoration proj ect.