There seems to be forward motion on the issue of the Waikiki War Memorial Natatorium, which is something to celebrate just by itself, considering how it’s defied resolution for 40 years.

And it’s especially encouraging that the city is considering a way to preserve the essence of the iconic World War I memorial, an option that, with proper vetting, shows real promise — if private or creative sources can be found and tapped to help pay for it.

It was in 1979 that the saltwater pool complex, complete with its ornate facade, was closed due to its deteriorated condition.

Ever since then, the discussion itself deteriorated to become a standoff between those who wanted the facility completely restored and those who, quite reasonably, worried that this would become a money pit.

In 2013, Mayor Kirk Caldwell and then-Gov. Neil Abercrombie were ready to throw in the towel on either option, favoring instead a relocation of the facade and a dismantling of the pool to convert that piece of shoreline to a beach.

At one point that sounded like a rational course of action — but a few years later, the National Trust for Historic Preservation came up with a hybrid that, after being further defined and explored by the newly released environmental impact statement, seems to be workable.

The plan, which the Caldwell administration has identified as its preferred option, would rehabilitate the Natatorium as an open-circulation saltwater pool with a perimeter deck supported by piles to be fixed on the nearshore ocean floor.

This, the city maintains, would enable active use of the enclosed swimming area without the full containment of a classic pool that would subject the facility to strict health regulations.

It’s a distinction that would save on some of the regulatory and upkeep costs of the full-scale restoration, projected at $42.7 million upfront with annual operations and maintenance expenses set at $1.13 million.

Construction costs and contingency allowances for the preferred perimeter-deck concept, including rehabilitating the bleachers structure that abuts the facade, are estimated at $31.8 million, less than the $35.2 million it would cost to demolish the structure and create a “war memorial beach.”

Where the adapted swimming complex would start quickly racking up the costs is in ongoing operations and maintenance — $967,000 annually, compared to $356,000 each year for the beach.

That is surely one vulnerability in the plan that needs bolstering. For one thing, the city could pare down its staffing costs and consider a limited strategy for monetizing the property. Visitors would like a place to buy refreshments and even limited beach supplies, so space for an appropriate vendor could help raise revenue to defray expenses.

In addition, collecting a modest admission fee for nonresidents could be considered, as well as donations from kamaaina who feel inclined to support memorial upkeep.

And right up front, there needs to be some private participation in finding construction money. The nonprofit Friends of the Natatorium and the National Trust should get ready to pick up the baton soon.

Also, if the project is to receive the permit it needs from the City Council, fears of swimmer entrapment between the system’s grating and the support structures must be addressed. The EIS suggests some preventive safeguards, adding that safety measures would be developed with input from concerned agencies.

If solutions can be found, the return of the Natatorium after four decades would be a welcome addition — for Waikiki visitors, surely, but also for residents who’d appreciate the rebirth of a historic attraction.