The Obama administration's latest plan for making 14 hydroelectric dams in the Northwest safe for salmon offers no major changes in strategy and continues to rely on habitat improvements to overcome the numbers of fish killed by the dams.

The 751-page draft of the court-ordered plan known as a biological opinion was released Monday by NOAA Fisheries Service.

The last plan was struck down in 2011 for depending too much on habitat improvements that weren't specific. That plan also failed to consider the possibility of breaching the four dams on the Snake River in Eastern Washington - a move that would return the river to more natural conditions.

The new plan also doesn't consider breaching the four dams. It said current dam operations are working fine, survival of juvenile salmon migrating to the ocean has improved and habitat improvements are on track to be implemented by 2018, when the biological opinion runs out.

The latest plan also noted that scientists can't explain a downturn in the past four years in the numbers of adult fish surviving the reach between Bonneville Dam on the Columbia and Ice Harbor Dam on the Snake in Eastern Washington.

The survival outlook for many threatened and endangered salmon runs remains risky. Landscape-scale habitat improvements are being ramped up on the Columbia Estuary, where spending is increasing from $4 million to $13 million.

"Our finding was that our original analysis was correct, so then it was not necessary to look at additional actions, including additional spill or dam breeching," Bruce Suzumoto, chief of hydrop operations for NOAA Fisheries, said in a teleconference with reporters.

Court ordered spilling of water over the dams, rather than running it through turbines, has increased the survival of young fish migrating downstream, but at the expense of power production. Breaching the four Snake River dams would eliminate reservoirs that slow the seaward migration of juvenile fish, make young fish more vulnerable to predators, warm the water, put obstacles in the way of adult fish swimming upstream and causes spawning gravels to be in deep water.

The plan suggests that dam operators could reduce the amount of spill for fish on the Snake dams starting Aug. 1, the tail end of the migration, if the numbers of fish passing the dams goes below 300. Spill currently runs through Aug. 31. A similar suggestion in 2008 was rejected by a federal judge.

Salmon advocates denounced the offering as a "Groundhog Day" plan, referring to the 1993 movie where the same day is repeated over and over.

"They seem to be trying the same thing over again, and hoping it will stick this time," said Steve Mashuda, an attorney for Earthjustice, the environmental law firm that represents salmon advocates in the lawsuit against the biological opinion. "That not only leaves them, I think, on shaky legal ground. But it squanders another opportunity," to improve fish survival.

Mashuda said they would have to wait to see what changes might come in the final biological opinion before deciding whether to go back to court.

The final plan must be submitted by the end of December to the U.S. District Court in Portland, Ore., where a new judge will be considering the case. Judge Michael Simon has taken over for Judge James Redden, who has retired.