Dams and barriers placed on Alameda Creek have prevented migratory fish from entering their native spawning grounds for more than 50 years, but an $80 million effort to raze the last significant obstacles and restore trout, salmon and other fish to their historical habitat are now underway. A PG&E gas pipeline is the last major barrier to restoring 20 miles of upstream spawning habitat for Chinook salmon and steelhead trout and will be relocated and buried by a coalition that includes the Alameda County Water District, PG&E and the San Francisco-based nonprofit California Trout. … The plan is to remove the concrete barrier and move the gas pipeline 100 feet downstream and bury it 20 feet underground to reopen the creek for migratory fish, according to California Trout senior project manager Claire Buchanan. Construction will need to move quickly in order to return the creek to its natural flow by Oct. 31, ahead of the fish migration season, Buchanan said.