As the transformation of Kakaako into an urban residential oasis rapidly approaches — the buildings are taking shape amid noisy construction work — the reality of thousands of new residents in the area is coming into focus.

It’s been estimated that the population of Kakaako will double by 2030, to about 30,000. Yet for all the housing going up, from studio-sized rentals to multimillion-dollar condos, one thing has been missing from this vision: A new public school.

That could change. At a public hearing before the Hawaii Community Development Authority on Wednesday, the state Department of Education and Forest City Enterprises Inc. unveiled a plan to transform 690 Pohukaina, bordering Mother Waldron Park, into a 400-unit affordable rental tower next to a new four-story, $40 million public elementary school. The new school would serve about 750 students, according to DOE assistant superintendent Dann Carlson.

In a nod to history, the school would be built in the same area as Pohukaina School, which went up in 1913 and whose most famous teacher was Margaret Waldron, also known as Mother Waldron, after whom the neighboring park is named.

The proposal makes sense. Families will need a place to send their children to school. Nearby schools serving Kakaako, Royal School and Queen Kaahumanu Elementary, were at capacity several years ago. Much of the nearby Kakaako developments include some kind of reserve or quasi-affordable housing component, which would attract families with school-age children.

Even so, the proposal is fraught with uncertainty, and the HCDA should proceed with caution.

First, it’s not clear how many families with young children will move into Kakaako. A 2014 study by the state Department of Business, Economic Development and Tourism, noted that studio and one-bedroom apartments, not to mention million-dollar condos — among the kinds of residences going up in Kakaako — might not attract young families.

Also, the DOE needs the Legislature to approve funding for the new school. So far, lawmakers have appropriated only $6 million. The proposed compact, four-story campus is an intriguing innovation, but merits a closer look.

Of greater concern, however, is whether the project can be modified and approved by HCDA and the landowner, the state Department of Land and Natural Resources. Forest City already has received tentative approval to build 804 rental apartments with two towers on the site, along with space for civic, community and commercial uses.

HCDA will have to decide whether last week’s revised plan fits the parameters of its original request for proposals. It’s not an easy call. The original RFPs and Forest City’s original plans did not include building a school. A legal challenge would cause further unproductive delays in the development of the long-languishing site.

If the HCDA wants a school at 690 Pohukaina — and consensus seems to favor the idea — it should issue a new request for proposals that includes one.