State lawmakers need to stop and do a little crystal-ball-gazing before squandering one of urban Honolulu’s most prized assets: the last remaining slice of public waterfront in the city.

The state Office of Hawaiian Affairs is pulling out all the stops to convince the Legislature it would be doing the right thing to pass Senate Bill 3122. The measure would exempt OHA from an 8-year-old ban on residential development on the makai portion of the Kakaako district, and allow for buildings 400 feet high, up from 200.

OHA appears to be gaining ground on this front, given that the bill has passed the Senate and, on Wednesday, got the critical approval of the House Finance Committee. Those at that hearing who contended — correctly — that this would put makai development on the wrong course will need to do some intense organizing and lobbying to stop the bill.

Opponents have a few strong arguments in their favor. One is captured in written comments from the state Department of the Attorney General, raising concern that the exemption may draw a legal challenge as "special legislation." That means it could be struck down, as was a similar exemption for the Superferry project.

OHA countered that it is not subject to the state Constitution’s requirement that the Legislature pass "general laws" over public lands: Special laws concerning the way state agencies use lands is allowed.

However, although the AG proposed language that would "minimize against a challenge," the concern remains. And considering the lucrative potential of residential development with unobstructed views, the risk of a private court challenge should not be dismissed by lawmakers.

There is also the issue of rising sea levels. Several people made the sober, rational point that proceeding with residential development in the inundation zone — especially now, in full awareness of the dangers from climate change — would be irresponsible.

But the core of the case against high-rise residential development on the waterfront is that it would by definition diminish the public enjoyment of the area. OHA trustees have promised a master plan for "something that will make us all proud." But considering that OHA seeks reversal of an important land-use law, a mere promise does not warrant special entitlements.

OHA got vigorous support from some in the Native Hawaiian community, who say the public would have a chance to weigh in on ways to "mitigate concerns." That’s fine, but there’s not much to be done to mitigate against 400-foot-tall towers.

Backers also said the enhanced entitlement would ameliorate the wrongs done to the indigenous population. Nobody at the hearing disputed that OHA was owed its settlement. Some even said they’d rather see additional redress made than to sacrifice their vision for an unobstructed Kakaako Makai.

That is really what’s at issue: Preserving the vision was a hard-won victory for the public interest, and the people shouldn’t have to fight that battle all over again.