On the doorstep to Waikiki, there’s a redevelopment opportunity that went wrong, but there’s still a chance to salvage something Honolulu desperately needs: affordable housing.

The Central YMCA at 401 Atkinson Drive has been put up for sale, which means 11 employees will be out of work and residents in 115 low-cost rental units will be displaced. It’s not unexpected, but the news still came as a jolt to those most affected.

All of Honolulu will be affected to some degree, because the residents in those hostel units will be added to the roster of those searching for affordable housing, and because the city is losing a community asset for good.

The Central Y’s imminent departure signals the need for the city to leverage the development value of the 1.8-acre prime property and secure something more generally beneficial than another block of high-end, luxury condominiums or condo-hotels.

This YMCA, open to the public since 1951, included a fitness center, pool and youth program facilities as well as the housing. Those facilities, except for the apartments, closed in 2015 in preparation for redevelopment.

All this had been expected to reopen with the new complex under a deal signed in 2012, when Y officials agreed to sell 1.5 acres of the site and to use sale proceeds to finance a new YMCA on the remaining land.

The property was to have been acquired by the San Francisco-based MB Property Acquisitions LLC and Aloha Kai Development LLC, an affiliate of Tama Home Co. Ltd. of Tokyo. But Aloha Kai struggled to complete its part of the purchase and start work, and after an extension of a deadline, the parties entered into arbitration talks.

In July 2016, the Y notified Aloha Kai it had terminated the agreement; the arbitrator ultimately awarded YMCA a $2 million settlement for the failed deal. That payment obligation was fulfilled recently.

Last week the nonprofit YMCA announced the property sale, adding that plans to rebuild its own facility had been withdrawn.

Surely, whatever new owner comes forward can’t be held to the same development plans, ideal though they had seemed for community use. But at least where affordable housing is concerned, Honolulu, already reeling from its housing shortage, is taking a blow from the loss.

And the city would be well advised to look for ways to secure some moderately-priced homes for sale or rent as a reconfigured development plan takes shape.

In 2013, the YMCA, represented by MB Property Acquisitions sought and eventually secured rezoning of the property from A-2 Medium-Density Apartment District, with a height limit of 150 feet, to High-Density Apartment Mixed Use District, with a height limit of 350 feet.

The land sits near the planned rail terminus at Ala Moana Center, but it won’t need to undergo review under the transit-oriented development (TOD) plan for the area a half-mile radius around the station. That’s because the owners already have the zoning entitled for the sale and would not be held to the affordable-housing requirements of TOD.

But the purchasers likely would want to improve on the deal, and may be open to renegotiating with the city what they would be willing to give for additional density or other incentives.

The Y system has a number of improvement needs and so will want to pitch the property as having the maximum building potential. But it’s the duty of the City Council and city administration to advocate for the public interest here: a healthy commitment to affordable housing.

Officials for the Y have said that they will work to relocate affected employees. That’s good; but there’s still reason to expect them, and others, to recognize how the closure will affect low-income renters, as well.