The House Resources Committee voted yesterday to make broad revisions to the Endangered Species Act by making it more difficult to list species as endangered and declare their habitat off-limits.

The two bills -- which passed by comfortable margins with some Democratic support -- reflect lawmakers' growing unease with the pioneering environmental law designed to protect plants and animals from going extinct. Bush administration officials and House leaders have repeatedly attacked the 30-year-old law as ineffective, and lawmakers said they hope legislation will offer relief to landowners who say they have been denied full use of their property to accommodate imperiled species.

House Resources Committee Chairman Richard W. Pombo (R-Calif.) said the act needs to be revised because it is "a failed managed-care program that checks species in but never checks them out."

A bill offered by Rep. Dennis Cardoza (D-Calif.) would raise the bar for designating critical habitat, which restricts federal activities on lands deemed essential for a species's conservation. Cardoza's bill, which passed 28 to 14 with six Democrats voting aye, would direct the interior secretary to designate critical habitat to the maximum extent "practicable," a change he and others described as essential for operations at military bases and economic development on public and private land.

But Rep. Nick J. Rahall II (D-W.Va.), the top Democrat on the panel, said Cardoza's bill would leave endangered plants and animals without room to recover. "What is practicable to me might not be practicable to the secretary of the interior on a bad hair day," Rahall quipped. "Without habitat, we know that species cannot recover, let alone survive."

The two sides also sparred over a measure from Rep. Greg Walden (R-Ore.) calling for an independent three-member panel to review any decisions under the law, including listing a new species or designating critical habitat. It would also weigh field data more heavily than computer modeling, which is also factored into the decisions.

Walden reminded his colleagues of what happened in 2001 in the Klamath River Basin, home to the endangered coho salmon and two types of suckerfish. In response to a lawsuit, federal authorities curtailed water flows to local farmers, costing them at least $20 million. The National Academy of Sciences later found there was insufficient scientific data to support the move, though environmentalists note that 34,000 adult salmon died in 2002 before they could spawn when authorities once again diverted water for irrigation projects.

"The government got it wrong. It hurt the people and it could have hurt the fish," said Walden, whose bill passed 26 to 15 with four Democrats in favor and one Republican against.

Democrats said Walden's plan could be subject to political influence and would delay critical designations for at least six months. Rep. Stephanie Herseth (D-S.D.) said "the panels will be tainted by politics" as opposed to the peer reviews that take place now.

Both bills could pass the House this year, GOP aides said, but are unlikely to make it through the Senate before adjournment.

Jim Sims, executive director of the industry-supported Western Business Roundtable, said the votes signal "a real political sea change" because the act's critics have calculated that it would be easier to modify it than repeal it outright. "There is a growing recognition and consensus on both sides of the aisle that this act needs to be modernized and updated after 30 years," Sims said.

But environmentalist Marty Hayden, legislative director of Earthjustice, said the two bills would gut the act by cutting "enough holes in that safety net to let an elephant slip through."

A farmer's sign near Oregon's Klamath River reflects resentment over the Endangered Species Act. A bill by Rep. Dennis Cardoza (D-Calif.) would require habitat designation to the extent "practicable."Rep. Greg Walden (R-Ore.) proposed an independent panel to review listing and habitat decisions.