More in sorrow than in anger, a grieving Sen. Howard H. Baker (R-Tenn.) might say that last year's bright idea has become this year's nightmare and must be laid to rest.

The bright idea was creation of a Cabinet level review board that would be the final arbiter over the fate of public works projects that might be stopped by the Endangered Species Act.

That approach was prompted by the controversy in Baker's home state involving the endangered snail darter fish and the nearly completed Tellico Dam of the Tennessee Valley Authority.

The Supreme Court held last year that TVA could not close the gates on its $120 million dam project because it had failed to provide protection for the tiny snail darter, a vanishing species in the Little Tennessee River.

The furor was immediate, opening a full-scale assault on the Endangered Species Act, which, coincidentally, was up for renewal at the time in Congress.

So at the urging of Baker and Sen. John C.Culver (d-Iowa), Congress set up the review panel as it extended the act, hoping to avoid controversies like Tellico in the future.

The new panel's first act was to rule unanimously in January that other, more economical, alternatives existed and that the Tellico Dam should not be finished. TVA has produced a substitute development plan to keep the river free-flowing and let the snail darter live.

But that, apparently, was not what Baker had in mind with his bright idea. The senator was furious at the decision of the panel, which could have been Tellico's ace in the hole.

"If that's all the good the committtee process can do, to put us right back where we started from, we might as well save the time and expense," said Baker.

His solution: exempt Tellico from coverage of the Endangered Species Act and abolish the review board, both of which he has proposed in legislation.

Both amendments will be up for consideration Wednesday when the Senate Environment and Public Works Committee meets to give final consideration to a new extension of the species-protection law.

A close vote is expected on Baker's proposal to exempt Tellico-particularly if he decides to go to the mat and call on friendly or leaning-toward friendly Democrats for help.

"It could be very close. We consider it even as of today," a committee staff member said last week. "On the merits, the exemption would be defeated, but if Baker really wants it . . . well, we don't know what will happen."

Culver, for his part, is keeping a low profile, saying nothing to rile the waters. But, a Culver aide said, the senator still thinks the review panel is a good idea worth saving.

What's more Culver thinks the panel has vindicated itself. It may have vetoed Tellico, but it also exempted the Grayrocks Dam in Wyoming from the act after project supporters promised not to flood the matting grounds of the rare and imperiled whooping crane. CAPTION: Picture, SEN. HOWARD H. BAKER . . . displeased with his brainchild