Residents shouted at each other at town-hall gatherings. One confrontation got so heated that a resident called the police. The governing board appointed a security guard to keep order at meetings.

Oakmont residents play pickleball—a game that’s like a gentler version of tennis, played with a paddle and a plastic ball with holes on a badminton-sized court. PHOTO: RACHEL BUJALSKI FOR THE WALL STREET JOURNAL

For many, of course, the issue wasn’t really about pickleball. It was about a divide that had opened between wealthier residents who moved to the village more recently and the less well-off, who said clubhouse updates, new fees and expensive amenities would be budget-busters.

Mr. Heyman’s predecessor as president was a leader of the anti-pickleball faction. She felt she had been chased out of office by pickleball partisans. On the paper bag was a note.

“You’re next,” it read, according to a police report.

Around 10,000 baby boomers are turning 65 every day, and the same number will continue doing so for years. Some are on solid financial ground after a lifetime of planning and the fortune of well-timed home purchases and stock investments.

Most of the rest are unprepared. Fifty-four percent of households with middle incomes—ranging from around $48,000 to $95,000 a year—don’t have enough saved to maintain their quality of living in retirement, according to the Boston College Center for Retirement Research. Some of those who saved were hit by unforeseen health-care costs. Others took on debt for education. Yet more made investment mistakes or lost their savings in the 2008 financial crisis.

Those wildly different circumstances are leading to hard-to-resolve social tensions, which are playing out every day at retirement communities across the country. In Oakmont, the issue was pickleball.

Founded in 1963, Oakmont Village was long an option for the middle class that benefited from California’s rising real-estate values. They could move into attached duplexes or triplexes or wood-sided single-family ranch-style homes and enjoy three swimming pools, a lawn-bowling green, honor-system lending library and the 130-plus clubs and activities.

Living near one another is an increasingly popular option for retirees. The population of the U.S.’s 442 federally designated “retirement destination counties” rose 2% last year, compared with the national average of 0.7%, according to Census Bureau figures. Retirement communities often provide social connections that can fray when people leave the workplace, live alone or have families spread across the country.

Steve Spanier, the current president of Oakmont’s homeowners’ board, said the mountain-view community started “moving more upscale” in recent years when retiring baby boomers in San Francisco and Silicon Valley discovered it on weekend wine-tasting trips to Sonoma County. Coming from places where real-estate prices are especially high, they began buying and gutting homes. The community has about 4,700 residents.

Steve Spanier on the back deck of his home in Oakmont.

The community now splits neatly into two camps. Some believe it should only “fix things that break,” he says. “Then there are people like the people who are starting to move in. They have a lot of money and want to live the lifestyle to which they’ve become accustomed and they want to do it here,” he says. “People are having more trouble getting along.”

The October wildfires that tore through Northern California’s wine country last year fleetingly eased the divisions, says Mr. Spanier. The fires forced Oakmonters to temporarily evacuate and destroyed two of the village’s roughly 3,200 homes. The fitness center sold “Oakmont Strong” T-shirts, and the mood mellowed for a bit.

“It got better for a period of time,” he says, “then that feeling of unity created by the fire left.”

Homes in the resident-owned Oakmont Village fetch between $350,000 for smaller dwellings up to about $1.2 million for ranch-style homes that have been remodeled by wealthy newcomers. A few years ago, million-dollar sales were unheard of.

Home Stretch

Sale prices for homes in Oakmont Village in Santa Rosa, Calif., are increasingly surpassing $1 million, creating a divide in wealth among its residents.

 million

$1.4

More than 2,000 sq. feet

1,601 to 2,000 sq. feet

1,201 to 1,600 sq. feet

1.2

1,200 sq. feet or less

1.0

0.8

0.6

0.4

0.2

0

1Q

2Q

3Q

3Q

2Q

3Q

1Q

1Q

2Q

3Q

4Q

1Q

2Q

3Q

4Q

1Q

2Q

3Q

4Q

1Q

2Q

2Q

4Q

1Q

4Q

3Q

4Q

’14

’15

’16

’17

’18

’13

2012

Source: Century 21 Valley of the Moon Angela Calderon, THE WALL STREET JOURNAL

After retiring in 2015, Iris Harrell sold her part of the remodeling company she founded in Mountain View, Calif., and says she is “never going to have to worry about money.” She and her wife, Ann Benson, sold their home in Silicon Valley for $3.8 million and bought a hillside ranch-style home in Oakmont for about $800,000, she says.

They raised the roof to allow for windows tall enough for a view of the top of nearby Hood Mountain. So they can age at home, they installed an elevator and added 1,300 square feet of space, including a spacious wing that could house a live-in caretaker. Ms. Harrell now calls the wing “the best guest suite in Oakmont.”

“We’re spoiled and we know it, but it just worked out for us,” says the fit 71-year-old.

She became the chairwoman of Oakmont’s building construction committee and set about trying to also refurbish the 55-year-old community.

Iris Harrell installed an elevator and added 1,300 square feet of space to her Oakmont home.

“You can’t be premier and look like the 1960s,” Ms. Harrell says. “It’s not making the statement we want.”

She says that retirees moving in—“post Google-ites” she calls them—are willing to pay for better amenities and that Oakmont’s future shouldn’t be dictated by the “small minority” who aren’t willing. She suggested those pinched for money should look into a reverse mortgage.

Oakmont resident Gary O’Shaughnessy, who lives in a unit of a triplex down the hill from Ms. Harrell’s house, calls that suggestion “insensitive.”

“That attitude I can’t live with,” he says.

A former school-bus driver for disabled children, Mr. O’Shaughnessy says a diagnosis of Parkinson’s led him to retire in his 60s, earlier than planned.

While he was working, he rented a house in Santa Rosa. He bought his place in Oakmont for $280,000 in 2010 with help from an inheritance from his mother and $50,000 from his own retirement account. He is single and 71 and has $40,000 in savings. His monthly income is around $2,000, from Social Security and a small pension.

He says he typically walks dogs seven days a week to “make ends meet”; his bills include a mortgage, supplemental medical insurance and more than $300 in monthly dues at Oakmont.

Gary O’Shaughnessy has started dog-walking to ‘make ends meet,’ he says.

Everyone in the resident-owned community pays $67 a month per person to the main Oakmont association, up from $58 last year. Households pay another $220 a month, on average, to various sub-neighborhood associations for services such as water or landscaping.

Mr. O’Shaughnessy started attending meetings and signing petitions as plans, backed by Ms. Harrell and others, proceeded for a roughly $300,000 tournament-quality pickleball complex with tiered spectator seating.

“There was a big fight and it kind of divided the community,” he says. “The people who have money just want to throw it around, but there are a lot of people on fixed incomes.”

A 2015 survey sponsored by the Oakmont association found that 48% of residents said they were very or somewhat concerned about their current financial needs. That figure rose to 57% for those under age 66.

Overall, 52% were “not at all concerned.”

“We are an extremely wealthy community,” resident Vince Taylor, a former software-company owner, said, during an open forum at an association meeting in March 2017. “We shouldn’t be acting like a poverty community.”

Vince Taylor in his backyard garden in Oakmont.

Mr. Taylor, who is 81 and retired, says he has more than $1 million in his retirement savings and lives off investment earnings without touching the principal.

His public comments provoked discussion on Nextdoor, an online neighborhood social-networking service. A discussion titled “Disparity of wealth in Oakmont” drew nearly 80 comments.

One Oakmont resident suggested retirees with tight budgets get jobs. Another, Bob Starkey, a 69-year-old renter and retired museum director, wrote that illness had depleted his savings and that he lived with anxiety his car might die.

Can You Afford to Retire?

See if your retirement nest egg is future-proofed

Age

Current income

Percentage of salary saved each month

Total savings

Include 401(k), 403(b) and 457 accounts; IRAs; brokerage and bank accounts

Equity in home

Home’s current value minus outstanding mortgage

Total debt

Include loans and credit cards; exclude mortgage

Planned retirement age

• 62
• 65
• 67
• 70

SUBMIT

“Please remember that pensions have become a thing of the past,” wrote Margaret Babin, a retired home-day-care operator who is 62 and is selling her collection of French Quimper pottery on eBay to pay for extras.

“At some events, I feel out of place even though I shouldn’t, because I’m doing OK,” she says, noting that she sees more fancy cars in the community. “The separation seems to be getting wider and wider.”

By early 2017, she and other frustrated residents had organized behind a slate of candidates who aimed to win a majority on the homeowners’ board and halt the pickleball project, which had been approved by Oakmont leaders but not yet built.

On the morning of April 3, a phone call woke up Ms. Babin. “I just couldn’t believe what I was hearing,” she recalls.

One day before the votes would be tallied in the election, a bulldozer was breaking ground on the pickleball complex. Supporters and detractors rushed over. One resident called the Santa Rosa Police Department at 7:24 a.m. to report a “verbal disturbance” at Oakmont.

“There is a heated argument going on at this time,” the police report said. An officer who went to the scene wrote that there were “two warring factions over a pickleball court.”

The next day, the candidates opposing the pickleball complex were victorious. Construction stopped.

“We face some of the same challenges as the rest of our state and our country,” Ellen Leznik, the new president, said at a public association meeting days later. “One such challenge is the disparity of wealth in our membership.”

Some pickleball proponents rose to defend themselves.

“We’re not the mean, vicious and entitled people our opponents and Nextdoor critics would have you believe,” one speaker said.

Oakmont eventually converted two existing tennis courts into six pickleball courts at a fraction of the cost. The new board ushered in a tone of frugality and oversight that some saw as heavy-handed. Rhetoric at public meetings grew so hostile that the board brought in a security guard to keep order.

“Why don’t we just wait till we’re all dead?” an Oakmont man who favored the pickleball complex declared at one meeting. “Guess what? Oakmont is our last stop. The train ends here. This is the Hotel California.”

Oakmont’s activities include a popular swimming aerobics class.

Resident Charlotte Martin on the patio of her duplex unit home.

Resident Nancy O’Brien outside her triplex ranch-style home.

Ms. Leznik, a 60-year-old former lawyer who retired early because of a disability, resigned less than four months after she became president, in July 2017. She says she had heart palpitations from the stress.

That left her ally, Mr. Heyman, as acting president.

The next month, at 9:15 a.m. on Aug. 12, the police again got a call from Oakmont, this time from Mr. Heyman, who is 61 and still works in corporate communications.

On Mr. Heyman’s porch sat “a bag containing the chopped off head of a rat,” according to the police report.

“It freaked me out,” says Mr. Heyman. He says he has “no doubt” the rat served as retribution for killing the pickleball project and for the disputes that followed.

At an association meeting soon after, another board member likened “the battle being waged at Oakmont” to “Armageddon.”

Mr. Heyman left the board and later moved out of Oakmont.

“There were clearly sides. One side felt that we’re an active-adult community and it’s our responsibility to provide activities and facilities to the membership,” says Oakmont resident Al Medeiros, 71, who now sits on the board. He counts himself in that group, which he says had been “vilified.”

Al Medeiros counts himself among residents who believe the community should provide activities and facilities.

“The other side seemed to think that well, we’re poor, so we really need to make sure our dues don’t go up and we should just provide the minimum,” he says.

In February, the board discussed remodeling a dated auditorium where hundreds of events, from dances to movies to meetings, take place every year. Some residents talked about constructing a new center and repurposing the old one into a state-of-the-art gym.

The board is also weighing a divisive request from the private golf club that borders many homes in the retirement community. The club is asking all Oakmont residents, golfers or not, to pitch in to help the club meet economic challenges. Someone suggested $5 a person every month.

Mr. Spanier, the new board president, says it “could potentially make pickleball look like a tiny issue.”

Oakmont Village, with views of Hood Mountain, includes roughly 3,200 homes.

—Heather Gillers contributed to this article.

Write to Jennifer Levitz at jennifer.levitz@wsj.com

Appeared in the October 5, 2018, print edition as ‘Wealth Gap Among Retirees Disrupts Old Age.’