The state Department of Education anticipates future residential development along the city’s rail line in urban Honolulu will bring with it an additional 10,200 students to area public schools, far exceeding existing capacity and requiring several new schools from Kalihi to Ala Moana.

The 20 existing schools serving students in the area can handle roughly 1,500 more students, DOE officials told Board of Education members Tuesday. Accommodating the forecast influx of students will require up to six new elementary schools, and roughly two new middle and high schools, as new residential neighborhoods pop up along the transit route in coming years.

The DOE is looking to establish a so-called school impact fee district to help generate the needed funds to build and expand schools. The proposed district — which would be the first in urban Honolulu — would run along a 4-mile stretch of the rail line, from the Middle Street rail station in Kalihi through downtown and Kakaako, and end at the Kona Street station near Ala Moana Center.

“A train running across the south shore of Oahu might not by itself increase the already forecasted population growth along the general area of its route, but the train will very likely concentrate future growth in the vicinity of the train stations,” the DOE said in a report supporting its recommendation for the new district.

The report says the city and state have plans to approve up to 35,000 additional residential units in the areas within a half-mile radius of nine planned rail stations from Kalihi to Ala Moana. The Hawaii Public Housing Authority also has announced 4,000 units as part of redevelopment plans for four housing projects close to the rail line.

“Adoption of the Kalihi-­to-Ala Moana School Impact Fee District will require developers to meet with the DOE and pay fees or provide land for schools. This would reduce enrollment pressure on existing schools serving the area,” schools Superintendent Kathryn Matayoshi wrote in a memorandum to the BOE’s Finance and Infrastructure Committee. “It will also add flexibility to the type of school sites provided, including facilities in high-rise buildings, remodeling of structures and redevelopment of school sites.”

A 2007 state law authorizes the DOE to collect fees from developers in high-growth areas of the state. The BOE in 2009 approved a West Hawaii school impact fee district on Hawaii island; a Central Maui and West Maui district in 2010; and a Leeward Oahu district in 2012.

The law requires developers in a designated district to provide the land needed for new schools or to pay a fee in lieu of land. A developer can opt to build a school instead of paying the fees. The land or fees charged are based on each new development’s proportionate share of the additional demand on public school facilities. The same formula to calculate fees is applied to both private and public-agency developments.

Developers also are required to contribute either 10 percent of new school construction costs or 10 percent of the construction costs of expanding an existing school.

“The whole idea of impact fees … is we’re charging the people who are going to place an impact on our school district with increased populations … instead of the entire population paying for that,” said Dann Carlson, assistant superintendent for school facilities.

Pending legislation this year would grant the DOE more flexibility when spending fees in the new district.

“The law now restricts fees in lieu of land to be spent only on school site acquisition and related expenses and not for construction costs,” the DOE report says. “The DOE is seeking an amendment … so that within the Kalihi to Ala Moana School Impact Fee District, fees in lieu of land can be used to acquire finished square footage within high-rise buildings.”

Under the law, at least one public hearing in the area has to be held before the BOE can take action on establishing a school impact fee district. The board Tuesday voted to move ahead with public hearings on the proposal.

If approved, the total all-cash fee to developers would be $9,374 per new unit in the Kalihi-to-Ala Moana district, DOE officials said. The maximum amount of school impact fees that could be collected within the district, if all 39,000 proposed units were built, would be 63.5 acres and $22.7 million in construction contributions.

By comparison, the fee in the Leeward Oahu impact district is $4,334 per multifamily unit, and $2,371 and $2,055 per multifamily unit in Central Maui and West Maui, respectively. The DOE said the formula for urban Honolulu reflects the higher cost per acre of potential future school sites within the proposed district.

To date, the DOE has collected roughly $800,000 in fees in Leeward Oahu and about $2 million on Maui. The department has yet to collect fees on Hawaii island because the county has been unwilling to alert the DOE when developers apply for building permits, according to officials.

Corey Rosenlee, president of the Hawaii State Teachers Association, testified in support of the overall proposal, but he asked the BOE to consider expanding school impact fee districts statewide to better fund public school facilities.

“The reality is that we’re sometimes behind the ball on collecting these fees,” Rosenlee said. “Kakaako has built thousands of units and has paid zero right now towards impact fees, and our schools are falling down and we’re running out of space. … We have this gap right now between all of these kids coming in and not having enough money for construction.”

The Hawaii Community Development Authority, a state agency regulating development in Kakaako, earlier this year rejected a developer’s tentative plan to include a public elementary school within a proposed affordable rental tower project on state land in Kakaako. The addition of the school, state officials contended, deviated from the original request for competing private development bids.

“We’re still pursuing that location,” Carlson said. “We were very disappointed in HCDA’s ruling. We’re not sure if the developer we were working with will come back to the table a second time, but the anticipation is that (the affordable rental project) will go out for another (request for proposal), this time they will actually include the school and hopefully the developer will jump on board.”

Carlson said the DOE had hoped to use the multistory school envisioned as a model for future DOE schools near all rail stations where dense residential neighborhoods are planned. “We were ecstatic about this because this was going to give us a blueprint of what we could hopefully draw along the entire area there,” he said.

Asked why the department didn’t seek a impact fee district in the area sooner, Carlson said that the 2007 law authorizing the fees was enacted before transit-oriented development was fully planned. “While we had worked to analyze the needs for the area and impact of the Kakaako area, the rail project began to become a factor and had to become part of the analysis,” he said.