The mayor of Los Angeles has announced a dramatic spending increase to tackle the city’s homelessness crisis, reflecting growing alarm in California over the number of people without shelter.

Mayor Eric Garcetti unveiled a proposed budget on Wednesday which would more than quadruple spending on homelessness, a response to critics who accuse authorities of ignoring the informal camps multiplying across LA.

Garcetti pledged $138m for the fiscal year that begins in July, a nearly fivefold increase from the $34m set aside in the current fiscal year. Sceptics however doubted the pledge would be fully realised.

The commitment helped nudge the city’s total annual budget from $8.58bn to a proposed $8.76bn.

It was the latest sign that policymakers were waking up to a crisis that has grown acute in the western United States. Cities in California, Oregon and Washington have recently declared states of emergency, or some kind of shelter crises, and sought federal help.

LA is arguably the epicenter. Its chronically homeless population has spiked 55%, to 12,536, since 2013, according to the Housing and Urban Development Department. Nearly all sleep on the streets.

Garcetti, a first-term mayor who has ruled as a cautious, centrist Democrat, triggered scorn last year when he vowed to declare a state of emergency, then changed tack and asked California governor Jerry Brown to do so instead. Critics assailed LA for allocating meager resources compared with New York City, which unveiled a $41bn affordable housing plan last year.

The mayor sought to regain the initiative with the budget proposal, which will go to the city council’s budget and finance committee for review. The full council must pass a budget by 1 June.

Calling the proposed budget “bold and prudent”, Garcetti said it would start making inroads. “This commitment represents a housing first strategy that we know works ... but that has not been scaled up enough to deal with the ongoing onslaught of new homeless individuals we see on our streets (who) have been pushed out, whether it’s from jails, foster care, whether it’s veterans returning home from war or folks who are pushed onto the streets by rising rents.”

Much of the increased funding is earmarked for the city’s homeless services authority, with smaller amounts earmarked for specialised LAPD teams tasked with dealing with mental illness and encampments.

However there are question marks over the funding. Nearly half of the $138m would come from fees and property sales that have yet to be approved, including $47m that will supposedly come from property the city will use or sell to others to develop affordable housing projects.

“Where are these properties located? Will the neighbours readily accept (affordable housing) projects there?” Kerry Morrison, executive director of the Hollywood Property Owners Alliance, told KPCC. “Will there be emergency provisions passed that will allow expedited development?” Morrison said the region needs a broad tax increase to fund homeless housing and services.

The city’s administrative officer Miguel Santana, who briefed reporters on the eve of the mayor’s announcement, agreed homelessness programmes needed steady funding streams to replace next year’s one-time-only funding sources.

“If a new funding source is not established at this time next year, then this funding source is in jeopardy and all of the programs it is supporting are in jeopardy,” Santana said. Earlier this year Santana’s office proposed a $1.85bn plan to build housing over a decade.

State senators, for their part, have proposed spending $2bn to provide permanent housing for mentally ill homeless people across California.

In a separate development this a westside councilman, Mike Bonin, this week proposed a plan to ease homelessness in Venice, where hundreds camp on beaches and streets every night. Bonin suggested allowing round-the-clock bathroom and storage access and turning a city-owned parking lot into low-cost housing.

There are about 80,000 chronically homeless people in the United States. One study by Columbia University and partners in New York City found that chronically homeless people given permanent supportive housing increased their odds of staying housed, while decreasing the time spent in jail or healthcare facilities.