San Francisco is certainly not the only city struggling to find answers for homelessness, but the scale and visibility of the problem has now been a source of infamy for decades. Recently, there's been a new focus on how the city's ever-increasing efforts to address homelessness, simply have not kept pace with the challenge.

"And so it's natural for people to go, 'What are we spending all this money on, how is this getting any better?" said Sharky Laguana, the chief data officer for the city's Homeless Oversight Commission. 

Laguana has been working to better understand why more people placed in housing—and more spending—hasn't translated into more success. To explain that, he wants people to think of the system a bit like people flowing through a pipe.

"This understanding of how many people are flowing in, and how many people are flowing out, that's critical to understanding where we are," he explained.

In the first part of this series, KPIX looked at this idea of system "flow" and how it might explain what we're seeing on the street. And in the second part of the series, KPIX looked at one very cost-effective way to improve flow, and that's keeping people from becoming homeless.

"I probably would have been one of the statistics out in the street," said Sheree Kaslikowski, for whom it was a matter of short-term rental assistance while she battled cancer, keeping her in her own home.

Now, the focus turns to the next part of the flow equation, and that's the people already inside city-provided housing. It's a population that has grown quickly in recent years, and very few of them are flowing out.

"Hey kitty," said Susie Melkonian, greeting her cat as she walked into her Tenderloin SRO.

Along with her cat, named Kid, Melkonian is settling into her Tenderloin SRO. She now has her own bathroom and shower, and she saves space with a convertible bed. 

"Like we're at the beach," she joked. "Goes down like that and you can put it up to chair level how you want it."

The small room, she says, is a blessing.  

"I was domestic violence homeless," she explained. "That's how I came to live in the hotels."

And for Susie, this hotel finally provides permanent supportive housing, after bouncing all through the city's system. 

"Been in shelters, safe houses," she said of her journey. "Transitional housing."

Where would she be were it not for this SRO?

"If it wasn't for this SRO, I don't know," she said. "I don't know where I would be."

"I pushed the city," recounted Randy Shaw, co-founder of the Tenderloin Housing Clinic  "The city was not using these hotels for permanent housing until we created the modified payment program in 1989. Prior to that, they were just used as temporary housing."

Shaw founded the Tenderloin Housing Clinic in 1980. When he started placing people in the city's old hotel stock, they were often very brief tenants.

"Yeah, it has changed dramatically," he explained of the shift. "When we first started doing homelessness and 89, the people I interviewed were all, like, laid off warehouse workers. The deindustrialization of the period impacted them. They wanted jobs. They were in our hotels for a very brief period, then they got a job, and then they weren't homeless anymore."

Thirty-six years later, the clinic's portfolio of more than 20 properties is a cornerstone of the city's efforts to house the homeless. A mission that in the 80s, often meant providing some temporary help. 

"But that's a very different world than what we inhabit now, where the people coming in are far more in need," Shaw said. "They have addiction issues."

"It's a variety of people to themselves who don't wanna be bothered with anybody," Melkonian said of her fellow SRO residents. "I've been through enough in life, just leave me alone. To the very mentally distraught, that really can't control their mental health. Cannot control it."

The city has tried to address the mental health and substance abuse challenges inside permanent supportive housing by deploying case managers, but the help simply has not kept pace with demand. What is supposed to be a case manager-to-housing unit ratio of one to 25 has sometimes been closer to one to 50.

"And the city says, 'We're funding case managers,'" Shaw said. "And we say, 'Well they're not required to use case management.' And often some of the most troubled people don't use case management, which they need the most."

Drugs and mental health, however, are only part of this story. Susie, for example, falls into another category. She, like 50% of the SRO population is disabled. And all of this brings us back to the idea of flow.

"Seniors, people who are severely disabled," Laguana explained. "Chronically ill. Severe mental health issues. Not everybody is a candidate for standing on their own two feet."

With an older, more troubled population, the challenges inside supportive housing are, in a way, driving the city's inability to find enough of it. More of those flowing in are not, or simply cannot, flow out. 

"When we put somebody in permanent supportive housing, it's permanent," Laguana said. "It's right there in the name. The challenge, though, is that if the average length of stay is 10 years, let's say. Then every 1,000 people you put into the system you only lose 100 every year on average. Let's assume 1,000 people are entering the system every year. And that's how, over the course of 10 years, 1,000 people become 10,000 people.

And then there's the growing cost.

"Your costs mushroom," Laguana said of the growing budgets. "Which is precisely what we've seen."

So it's another way in which the city's successes, putting more people in housing, are being obscured by the fact that more people are becoming homeless, many of them with nowhere else to go.

"So I wouldn't be able to," Melkonian said. "I couldn't afford to live anywhere. I wouldn't be able to live anywhere. And that's pretty sad. That's pretty sad because I'm not the only person like that. There's so many people that are in the same predicament as me. That's why I say, we should be grateful that they have places like this, these SROs, that we can live in. That's affordable. "

The Lurie administration has started making changes to how assistance is offered on the street, and who is eligible for housing. 

It remains to be seen what changes might come for those who are already inside. 

And all of this raises some obvious questions, like who is getting out of permanent supportive housing? What is the best way to get people who can stand on their own two feet moving in that direction? 

Now, many of these issues have developed over generations, and in recent years the city has vastly expanded supportive housing. So the scale of the challenge has grown, and the city's new budget constraints will only make solutions that much more complicated.