FIVE MONTHS AGO, a memo quietly threatened a low point for Portland housing policy.

The six-page document, authored by a high-level Portland Housing Bureau employee and sent to eight interested parties, warned that the city's already tepid goals for developing cheap housing in the South Waterfront were likely out of reach.

For years, the neighborhood had sent shimmering glass condo towers skyward while modest promises to add nearly 600 "affordable" units into its blocks went mostly unfulfilled (a crushing recession didn't help). Suddenly the housing bureau thought we'd have to curtail those as well, chopping its ambitions by around 150 apartments.

It might have been a sighing, shrugging-of-the-shoulders moment in this city. Instead it turned things on their head.

Today, Portland might be on the verge of tripling the number of affordable apartments in the South Waterfront from just over 200 to more than 600.

The latest hope? Sources say the Portland Development Commission (PDC) is perhaps weeks away from a deal to buy a piece of the largest chunk of vacant land in Portland's central city—an acre plot on 33 riverside acres currently owned by the moneyed Zidell family. The land could host up to 200 brand-new affordable units.

"They're heading into the final stretch with Zidell," says Commissioner Nick Fish, who's been working with Commissioner Amanda Fritz's office, the PDC, and others to reach an agreement. He anticipates a deal—in the $3 million to $5 million range—within the month.

Not all of Portland City Hall is quite so optimistic, but if Fish is right, it's a neck-snappingly quick change of tune at a time when growing income inequality and rising rents are sending Portlanders fleeing for the bargain housing of the suburbs. The affordable housing numbers being bandied about—including an additional 200 new units already promised by the PDC—could put the city well over its old goals for housing priced at a maximum 60 percent of median family income. (They wouldn't, notably, achieve what most people agree the real goal should be, which is to have a South Waterfront that reflects the economic makeup of the city as a whole).

It's also a testament to a little old-school activism.

"That memo was the spark that lit the fuse," says Fish. "Affordable housing has now crashed the urban renewal debate."

Fish is quick to throw credit to people who've been advocating for cheap housing forever. Debbie Aiona of the League of Women Voters became an awfully squeaky wheel when the housing bureau was talking about chopping housing goals. So did Gretchen Kafoury, the former state legislator and city commissioner who was pushing for more affordable housing in South Waterfront just weeks before her death last month.

"Believe me, I know how hard this is," the Oregonian quoted Kafoury testifying before city commissioners in late February. "But I still don't think this is enough."

Zidell deal or no Zidell deal, council's on the verge of making a commitment Kafoury might have cheered.

Fish recently convinced Mayor Charlie Hales to postpone a vote on a series of tweaks to the city's urban renewal strategy so he could introduce an April 1 resolution more or less committing the city to buy an acre of land in or around South Waterfront for affordable housing.

It's the same deal, of course, that Fish says is on the verge of taking place.

But if that falls through, it's also a promise, at a time when it'd be lovely to think promises still mean something.