The syncopated pounding of waterfalls, sweeping crescent wall and symbolism proposed for the Martin Luther King Jr. Memorial along the Tidal Basin were heartily endorsed by the National Capital Planning Commission yesterday.

The project design made a board of commissioners often embroiled in controversy go atwitter with such compliments as "borders on genius" and "I wish all our decisions were this easy."

It was what didn't happen at the monthly meeting that caused an uproar. One day before the meeting, the commission told proponents of a Vietnam Veterans Memorial visitors center that their project would not be considered yesterday, prompting outrage and theories of a roadblock from the center's chief supporter, Jan C. Scruggs, president and founder of the Vietnam Veterans Memorial Fund.

"We're not going to take this laying down," Scruggs said.

The planning commission described its action as a minor delay, saying that it was nothing more than a request for an environmental impact assessment of the site.

"We want to be sure we've got it right. We want this project to be approved; we want it to go forward, unimpeded," said John V. Cogbill III, chairman of the National Capital Planning Commission. "We realized we needed more information to do that."

For Scruggs, known for his tenacity in bringing the memorial wall to Washington and then having his fight re-created in a television movie, the decision will lead to more than a short delay.

He said the environmental study the commission is requesting will take 18 months and cost thousands of dollars.

The law authorizing the construction of an underground visitors center to complement the Vietnam Veterans Memorial was passed in 2003.

Scruggs has since fought for approval for a site beneath a patch of land north of the Lincoln Memorial near the wall, an area that soon will be home to National Park Service kiosks.

The National Park Service backed the Scruggs plan, and the site received reluctant approval from the other group involved in such decisions, the Commission of Fine Arts.

Scruggs said he provided a preliminary environmental site analysis to the National Capital Planning Commission, but that the board is making an unusual request for even more information.

Cogbill said the request is standard, especially for the last few projects approved by Congress for the limited space on the National Mall.

At yesterday's meeting, the road to approval was much shorter for the Martin Luther King Jr. Memorial.

The commission unanimously approved the design for the memorial, which visitors will enter by walking through a giant split rock that will resemble the "mountain of despair" from King's oratory. Through that mountain, visitors will come to a plaza embraced by a curving wall, engraved with bits of King's speeches and covered in clear sheets of cascading water, which will splash in the rhythm of King's syncopated cadence.

In the center of the plaza will be a giant rock with King's likeness, the missing piece of the entrance and the metaphorical "stone of hope" hewn from a "mountain of despair."

The commission asked designers to reconsider a footbridge that might block the view of the stone, examine the 12-foot width through the entrance and refine their information on the wall height.

After the plan's swift approval, there was a touching moment. The commission staff member who had worked on the King project, David Hamilton, announced his retirement after his presentation and received a standing ovation.

Hamilton began his career at the commission 25 years ago, working with Scruggs to get the Vietnam Veterans Memorial built.