With scores of Central Oahu businesses already feeling the brunt of rail construction, city leaders want to create a fund that offers them relief — but those leaders haven’t yet determined where the money would come from or at what total amount.

Honolulu City Council Budget Committee members unanimously passed a resolution Wednesday that would make it city policy to aid local businesses whose revenues take a hit during construction of the 20-mile, 21-station project.

They also advanced on second reading Bill 42, which would create the "transit construction mitigation fund" for the businesses affected to receive loans or even grants.

Construction of the elevated rail guideway is reportedly already having an impact on businesses in Waipahu. The rail shafts and columns are expected to make their way into town next year, with the rail line ending at Ala Moana Center.

Meanwhile, merchants at retail hubs such as Pearl Kai Shopping Center, located next to the future rail line in Aiea, have voiced concerns in recent weeks that turning lane closures and other traffic problems caused by rail construction will severely harm their bottom line — and could even put some out of business.

"We have to help these small businesses," Budget Chairwoman Ann Kobayashi said Wednesday.

But it’s still not clear where the city would get the money. The project is spending millions of dollars to compensate businesses affected by real estate property acquisitions. However, federal restrictions prohibit rail officials from using any of the federal construction funds to compensate businesses whose revenues are affected by the traffic and closures, according to Dan Grabauskas, executive director for the Honolulu Authority for Rapid Transportation.

In their discussion Wednesday, City Council members seemed interested in tapping some of the rail proceeds raised by Oahu’s 0.5 percent general excise tax surcharge. However, Grabauskas said his agency isn’t sure whether they could "carve out" those GET funds to be used apart from the restrictions on federal transit dollars.

Using GET funds could also potentially siphon that money away from actually construction, officials added Wednesday.

In some other cities, the local chambers of commerce and banks set up programs to help small businesses trying to stay afloat during rail transit construction, Grabauskas said.

"It’s a community effort," he added.

City officials are modeling the local mitigation fund effort in part after a similar $50 million Seattle-area fund launched in the early 2000s, to help businesses there trying to withstand several years of construction for a new light rail line.

Some 10 percent of the affected businesses that got help from the Rainier Valley Community Development fund during construction shut down, compared with 22 percent of affected businesses that didn’t seek help from the Seattle-area fund, language for the new Honolulu resolution states.

Most of the Seattle-area fund to help business was paid for with federal Community Development Block Grant funds. After Wednesday’s meeting, Kobayashi said she’s "always opposed" to such money going to city efforts instead of private and nonprofit groups.

The mitigation fund bill next goes before the full Council on Wednesday to further weigh the issue.