PANTHER CREEK - The clear water splashing through rocky pools and over gravel bars in this remote Amador County stream might signal hope for other trout streams throughout the Sierra Nevada.

Three years ago, Pacific Gas and Electric Co. paid crews to remove a dam on West Panther Creek that had been part of the company's hydroelectric generation system but also had blocked trout migration for more than seven decades. That removal was one of the first under the guidelines of modern environmental law as part of a deal that allowed the relicensing of PG&E's Mokelumne River Project.

Every 30 years or so, the Federal Energy Regulatory Commission reviews dams it licenses to see if their operations are still serving the public interest and meeting all applicable laws. This relicensing process gives boaters, environmentalists and other interests a chance to ask for changes.

Now, volunteer conservationists and government biologists are visiting Panther Creek several times a year to measure its progress. They've found that the stream easily tossed downstream hundreds of tons of gravel that had plugged the area behind the dam. They say Panther Creek's ability to resume its life as a trout stream means such restoration likely will work elsewhere as well.

"The dam starved the downstream reach of sediment and river bar material," said Jan Williams, a fishery biologist for the U.S. Forest Service. "River bars are where the habitat is."

Williams said gravel bars and sandbars are valuable because they create pools where insects and plant life can thrive and trout can feed.

On a recent Tuesday, Williams joined a small crew from the Foothill Conservancy to use laser surveying equipment to measure the riverbed in the area once blocked by the dam. Earlier in the year, other crews had taken measurements and surveyed the size and distribution of the sand and gravel in the stream bed.

"The first time we did it, it was almost all sand and a little gravel," Pete Bell, vice president of the Foothill Conservancy, said of the pebble surveys that started after the dam removal. Now, Bell said, the surveys find almost entirely gravel, as is appropriate for a mountain trout stream.

Things are going so well on West Panther Creek that the Foothill Conservancy is raising money to complete the removal of a sister dam on East Panther Creek that was breached but not completely removed in 2003.

The stakes are huge, at least for trout and for conservationists who care about trout. Jeffrey Mount, a professor of geology at University of California, Davis, and director of the university's Center for Watershed Sciences, said no one knows exactly how many small dams there are on California mountain streams, but he thinks one widely discussed estimate of 400 is probably low.

"Every one of those dams creates an ecologic 'discontinuity' in Sierran streams," Mount said via e-mail. "They block the movement of organisms up and down the stream, they disrupt the transport of sediment necessary for sustaining aquatic and riparian habitats, and they alter the hydrology that native species are all adapted to. So, if you are interested in restoring the ecological integrity of Sierran streams, removal of these small dams is a priority."

Conservationists readily admit that many, perhaps most, Sierra dams will stay where they are for the foreseeable future simply because the energy they generate is far too valuable to justify removal.

But they say there are likely many others like the West Panther dam whose value is relatively low. The West Panther dam had silted up completely by the late 1990s. It had no powerhouse of its own but instead sent water down a pipe to turn turbines at a site miles away, and that only when the big reservoirs were short of water. And finally, it would likely have cost millions of dollars more to upgrade the dam to modern environmental standards (through fish screens, fish ladders and so on) than the dam was worth.

Chuck Bonham, California director of Trout Unlimited, says the success of the West Panther dam removal already is making it easier to negotiate for removal where other dams of marginal economic value block trout streams. He said one example is the PG&E-owned Kilarc-Cow Creek project in Shasta County, which appears headed toward decommissioning under a tentative deal reached last year between the utility, conservationists and government agencies.

"They know that it is possible," Bonham said. "They know that it has been done."

Contact reporter Dana M. Nichols at (209) 754-9534 or dnichols@recordnet.com.