Three years after unveiling images of what Hawaii’s first vertical public school could look like, the pioneering project envisioned for Kakaako is in limbo.

Building of the 10-story elementary school was expected to be started last year by a private developer in conjunction with a moderate-price rental apartment tower on state land next to Mother Waldron Park.

But Hawaii lawmakers recently decided not to include $20 million for the school in a supplemental capital improvement spending authorization running through June 2021.

The nixed funding and other issues mean that the estimated $60 million school and associated residential tower likely won’t even break ground this year — a delay that follows prior difficulties for the project, which is known as 690 Pohukaina and began eight years ago as an effort to deliver badly needed affordable housing on state land.

State Sen. Gilbert Keith- Agaran, vice chairman of the Senate Ways and Means Committee dealing with budget issues, said the $20 million proposed in an early draft of House Bill 2725 for the Kakaako school wasn’t needed in the next year because the project isn’t prepared for construction.

“It’s a practical thing,” he said. “We were looking to put money into projects that will be used soon.”

A final version of HB 2725 with no money for the Kakaako school was passed May 11 and forwarded to Gov. David Ige.

It’s publicly unclear why efforts to build the school and apartment tower are lagging, or whether there is an updated timetable to start construction.

State Department of Education officials could not provide responses on these issues in recent weeks.

Devising detailed plans to produce a first-ever vertical school in Hawaii in conjunction with a 390-unit residential tower built by a private developer on land leased from the state is a complicated task, and the estimated cost for the school has risen from an initial $40 million to $60 million. That could be one factor.

The DOE previously received $20 million for planning and design work on the school, which is dubbed Pohukaina Elementary and is projected to serve 750 students within Kakaako’s growing population driven by high-rise development.

The tentative developer of 690 Pohukaina, Jon Wallenstrom of local firm Alaka‘i Development, recently said he accepts the pace of work for the project. But he was unavailable to comment on what issues have limited progress other than to say that the school is still in a design phase with efforts to understand how it can best serve the urban community.

If development proceeds with Pohukaina Elementary and the adjacent rental housing tower, it would realize a goal that stretches back decades to maximize use of a mostly vacant 2-acre site where a public school existed a century ago.

The work by Alaka‘i is tied to a 2012 request for development proposals issued by the Hawaii Community Development Authority, a state agency regulating development in Kakaako.

The HCDA selected a plan by Ohio-based Forest City Enterprises to build a pair of towers with 804 apartments for rent at mostly high-moderate rates.

Forest City anticipated breaking ground on 690 Pohukaina in 2014, but negotiations with the HCDA moved slowly and hit an impasse.

Part of that impasse appeared related to simmering frustration from DOE officials that the HCDA and developers weren’t addressing stress being put on regional school capacity by a wave of new high-density housing towers rising in Kakaako.

At one point the DOE forecast a need for nine new schools — six elementary schools, 1-1/2 middle schools and 1-1/2 high schools — between Kalihi and Ala Moana to accommodate dense residential development partly driven by the city’s planned rail line.

In 2015, the DOE pushed to make an elementary school part of 690 Pohu- kaina, and received $6 million from the Legislature to advance the goal.

Forest City embraced the school idea and revised its plan to one tower with 400 residences next to a midrise school.

However, the HCDA decided that such a change departed too much from its competitive bid proposal, and rejected the idea.

Another state agency, the Hawaii Housing Finance and Development Corp., then stepped in and offered to negotiate a development agreement for housing and a school on the 690 Pohukaina site.

In 2016, the HHFDC elected to work with Alaka‘i, a firm formed by Hawaii executives of Forest City.

Alaka‘i’s plan calls for 390 apartments reserved for moderate-income families and projected monthly rent starting at around $2,500.

The HHFDC also anticipates issuing a future request for proposals to develop a smaller, second tower on part of the site for low-income rental apartments financed in part by tax credits.

In 2017, DOE officials showed off conceptual renderings of what was touted as a potential model for more new schools in urban Honolulu as housing towers proliferate in the urban core close to planned city rail stations.

The rendering of the 10-story school featured big glass windows, multiple lanai and a courtyard. A common parking lot and driveway shared with the tower were also part of the plan.

“Just imagine a family living in the Kakaako area, and particularly in our future rental community, who will be able to drop their kids off at school and walk or bike to work in the nearby urban core,” Wallenstrom said in a statement at the time. “It will provide the people of Honolulu with a marvelous lifestyle and will help address public school expansion needs in an area undergoing change. We are honored and excited to help solve two of urban Honolulu’s most pressing needs: educational innovation and affordable housing.”

The Legislature by this time had increased its appropriation for Pohukaina Elementary to $16 million to cover planning, design work and initial construction costs for what was then an estimated $40 million school.

HHFDC recently said that as of late last year the DOE had received $23 million for the project, now estimated to cost $60 million.

In addition to more money for the school, Alaka‘i needs to negotiate a development agreement with the DOE and complete pending negotiations for a development agreement with the HHFDC that includes financial terms for leasing the land under the tower.