After years of unsuccessfully trying to clear their streets of a relentlessly regenerating homeless population, public officials in four Bay Area counties have separately hit on the same battle plan — a building boom of affordable housing for the very poor.

It means asking voters to throw money at the problem. A lot of it.

All told, local measures on the Nov. 8 ballot would generate $3 billion over the next 25 years to build affordable housing and provide services for the down and out. Community leaders from San Jose to San Francisco say they can’t remember when so much funding for the problem of extreme poverty has been tossed before the voters at the same time.

“I have absolutely never seen this much attention to homelessness at the same time throughout the Bay Area,” said San Francisco Supervisor Mark Farrell, who is among those advocating for Mayor Ed Lee’s proposed 0.75 percentage-point boost in the sales tax, to 9.5 percent, which would raise $50 million a year for homeless services.

“The reality is that homelessness is a regional issue, but we do not receive enough support from our state or federal government, so it’s left to the local cities and counties to do the job,” Farrell said. “In San Francisco, we’re going to do our part, and it certainly looks like other counties are stepping up to the plate, too.”

The other counties stepping up are Alameda, Santa Clara and San Mateo, which with San Francisco have a combined homeless population of 19,000 people. The $3 billion in proposed funding could create at least 20,000 affordable apartments.

The core problem in the Bay Area isn’t that homelessness has exploded in numbers — it’s remained relatively flat. In San Francisco, the street population has been stuck for a decade at about 6,700, and it fell in Santa Clara by 14 percent to 6,500 over a three-year stretch, according to counts done by both counties in 2015.

It’s just that the problem never goes away. And as the Bay Area tech economy ignites gentrification in formerly tatty neighborhoods, tent camps that were once in overlooked alleyways are rubbing up against people who aren’t used to them.

In the past couple of years, Jasmine Tarkoff has helped convene meetings of poverty agency leaders from all over the Bay Area to plan for housing programs and the funding measures on this year’s ballot — and she said she feels a new region-wide momentum for dealing with the street crisis.

“We don’t need to reinvent the wheel here. We can look at what other counties are doing, see what works and cooperate,” said Tarkoff, organizer with the Multi-faith Action Coalition in Contra Costa County.

“We’re very excited to see how the other counties respond to these measures on the November ballot, and what we might be able then to do ourselves in Contra Costa,” she said. “There is not one silver bullet for addressing the housing and homeless crisis here, or anywhere in the Bay Area. It’s going to take all approaches.

“And we’re all going to keep talking.”

San Francisco’s sales-tax ballot package, Propositions J and K, requires a simple majority for passage and would pump about $1.2 billion into homeless housing and services for the next 25 years.

Other measures on the ballot: In Alameda County, a two-thirds vote for Measure A1 would authorize a $580 million bond for affordable housing, particularly for the homeless. A simple majority vote for Measure K in San Mateo County would extend a 3-year-old half-cent sales tax for 20 years, totaling about $300 million. And in Santa Clara County, a two-thirds vote for Measure A would authorize $950 million in bond money for affordable housing, most of it for supportive housing for people who are now homeless.

There is no organized opposition to the proposals, although in San Francisco, Supervisor Aaron Peskin submitted ballot arguments contending that with a record $9.7 billion budget, the city is already taxing its residents enough. He called sales taxes a regressive tool for “balancing our budget on the backs of the poorest and most vulnerable in our city.”

Lee’s rebuttal contends that the majority of the sales tax would be paid by “big corporations and wealthy people.”

The local ballot measures are being echoed at the state Capitol, where there is also unusual momentum on homelessness.

In July, Gov. Jerry Brown signed a bill authorizing $2 billion for housing for homeless people with mental illnesses, the biggest investment of its kind in years. And Wednesday, the Legislature sent him a bill by state Sen. Holly Mitchell, D-Los Angeles, that would encourage cities and counties to use the “housing first” technique of quickly moving homeless people inside before their addictions or other troubles are cured. The governor has until the end of the month to sign or veto it.

“This is somewhat unprecedented on a statewide level in this way, but the senator thought this was a route we ought to go on given the urgency of the problem,” said Mitchell’s spokesman, Charles Stewart. “The plan is to move things forward on a statewide level without usurping local initiatives, and to marshal more thoughtful support. We want to help everyone move forward together.”

Farrell said any new state attention would be welcome as long is it doesn’t come with a muffling layer of additional bureaucracy. But the very fact that discussions and new funding are happening is encouraging and overdue, he said.

“Unfortunately, it takes the homeless situation to become more visible in every jurisdiction for people to perk up and pay attention,” Farrell said. “That is exactly what has happened recently.”

In the past few years, efforts on homelessness in San Francisco have picked up as the city increased street outreach, created a new homeless services department, opened one-stop Navigation Center shelters and authorized more housing money. But none of that has erased the street problem, and complaints still pour in daily from neighborhoods about new tent colonies.

Part of San Francisco’s problem is that, according to homeless counts taken over the past decade, 20 to 30 percent of its transients first started living without a roof somewhere else, then came to the city. Other counties report similar findings.

Creating more housing in the counties with the most pressing homeless crises — San Francisco, Santa Clara and Alameda in particular — will help stem such migration, give street people some stability and increase the chance of long-term success for people, case managers say.

Jeff Kositsky, head of San Francisco’s new Department of Homelessness and Supportive Housing, said he’d love to see the Bay Area more coordinated in its approaches, “and once we get our legs under us, we can talk more to other counties about that.”

“How can we share data and strategize, see where the best success can be found for individual people?” he said. “My dream is that someday we will do that.”

South of the city, homeless-aid leaders in the Bay Area’s most populous county are trying to take the lead in the region with the biggest, quickest infusion of housing cash.

Jennifer Loving, executive director of the nonprofit Destination: Home, said Santa Clara County’s $950 billion bond measure is the culmination of Silicon Valley’s realization that housing homeless people is cheaper than leaving them on the street, where many of them repeatedly require expensive emergency services.

“The chronically homeless folks aren’t going to just fix themselves. You have to give them a place to live, and then you can work on their issues,” Loving said.

As she made the rounds of San Jose tent camps the other day with Sacred Heart Community Service outreach worker Anthony King, Loving ran into hard proof of that truth over and over. Most people they met had been helped by counselors before, but they had never been given a good option for moving into housing. So they stayed outside.

“People try to say you have to pull yourself up by your bootstraps and all that, but when you try and government and the rest take too long, make too many appointments, don’t have enough housing, it gives you hesitation for taking the next hand that’s offered,” King said. “You give up.

“If we really get enough housing, readily available, it could be a game changer.”

One of the tent camps they visited held six people — Maricela Salgado, who had recently lost her motel housecleaning job when she injured her knee, her teenage daughter and their four young friends. They’ve been homeless separately or together in San Francisco, Pacifica and Modesto, and have never been able to score secure housing.

“I went to San Francisco, but I couldn’t find a good place to be homeless, so I always came back here where at least I grew up and knew the landscape,” Salgado, 42, said as traffic from intertwining Interstate 280 and Guadalupe Freeway roared over her head. “I look for jobs, my daughter looks for jobs, but when you’re living out here, it’s hard to get to appointments. Hard to stay clean.

“If the government can help us pay our rent, maybe we can get by.”

“You shouldn’t have to be living like this,” said Loving. “Let’s get you inside. I won’t forget you.”

Even as she spoke, she knew the chances of finding housing in Santa Clara County would be tough. Every time housing units open up for the homeless or poor, they are overwhelmed — one recently opened 70-unit complex in San Jose immediately drew a 6,500-person waiting list.

Nonetheless, hundreds of homeless people do get housed through the county’s network of nonprofits every year. And if the November bond measure passes, Loving told Salgado, there will be much more coming online.

Salgado teared up as Loving promised to come back. “You really think things could happen?” she said.

“Yes,” said Loving. “Don’t give up.”

Kevin Fagan is a San Francisco Chronicle staff writer. Email: kfagan@sfchronicle.com Twitter: @KevinChron

Bay Area measures

Measures on the November ballot to fund housing and services for the poor and homeless:

San Francisco Proposition J: Creates a Homeless Housing and Services Fund to route $1.2 billion into homeless housing and services over the next 25 years. Needs a simple majority to pass.

San Francisco Proposition K: Raises the city sales and use tax by 0.75 percent, to 9.5 percent, to raise $50 million a year for the Homeless Housing and Services Fund and $100 million a year for transportation. Needs a simple majority to pass.

Alameda County Measure A1: Authorizes a $580 million bond for affordable housing for low-income and homeless people. Needs a two-thirds vote to pass.

San Mateo County Measure K: Extend s a half-cent sales tax for 20 years, totaling about $300 million for affordable housing. Needs a simple majority to pass.

Santa Clara County Measure A: Authorizes $950 million in bond money for affordable housing. Needs a two-thirds vote to pass.