Mayor Bill Euille smiles after voting at Charles Houston Recreation Center. (ASTRID RIECKEN/For The Washington Post)

Four-term Alexandria Mayor William Euille lost in his Democratic primary Tuesday to Vice Mayor Allison Silberberg, a stinging defeat that illustrates voter concern over a wave of development sweeping the historic riverfront city.

Euille, 64, who was raised in Alexandria public housing by a single mother, has had a storied political career. He had not faced a primary challenger since 2003, when he was elected the first African American mayor in the city’s 266-year history.

But during a spirited race that included a second challenger, former mayor Kerry Donley, Euille faced pointed questions about why some key projects had stalled or fallen behind schedule as well as whether all the building planned for Alexandria could overwhelm its small-town feel and colonial charm.

With all ballots counted, Euille trailed Silberberg by 312 votes, or just over 2 percent, according to unofficial returns.

The race was one of several primary contests Tuesday in Northern Virginia. All were in Democratic-leaning districts, meaning that the winners will be heavily favored in November’s general election. Each race focused on questions about development, school crowding and traffic — vexing issues in the densely populated suburbs.

Mayoral candidate Allison Silberberg thanks a poll worker after she votes at the Agudas Achim Congregation. (Jabin Botsford/The Washington Post)

In Fairfax County, longtime Mason District Supervisor Penelope A. Gross (D) fought off an energetic challenge from Jessica Swanson, an educator who accused Gross of failing to adequately fund public schools and of being too cozy with developers. And Dan Storck, a member of the school board, beat out three other candidates for the nomination to succeed retiring Supervisor Gerald L. Hyland (D-Mount Vernon).

In Arlington County, Katie A. Cristol and Christian E. Dorsey won the Democratic nominations for two open seats on the Arlington County Board, according to unofficial returns. The outcome of those races in November will determine whether the board continues to support high-level and sometimes expensive government services or shifts to a more cost-conscious approach.

Silberberg, 52, said she wants to grow Alexandria’s economy in “a balanced way” and rebuild the people’s trust in government. During the campaign, she said, she came across “example after example of people feeling they were not being heard.” To start, she said, she will have fewer executive council sessions, where discussions are held behind closed doors.

“I’m not anti-growth or anti-development,” Silberberg said. “I’m for development that fits and is to scale.”

So far, she faces no Republican or independent opponent in November.

Euille said he would not rule out a write-in candidacy in November.

Four-term Alexandria Mayor William Euille lost the Democratic primary Tuesday to Vice Mayor Allison Silberberg. Silberberg was the only City Council member to vote against Alexandria’s waterfront redevelopment plan which earned her support from historic preservationists. (WUSA9)

“All options are on the table,” he said. “I’m still the mayor until November of 2015. There’s still some opportunities for some strategies to be at play between now and then.”

Silberberg was elected to the Alexandria City Council three years ago with the highest vote total of any council candidate, which qualified her to serve as vice mayor. She almost immediately voted against Alexandria’s waterfront redevelopment plan, which she had campaigned against, calling the two hotels and condos that were planned out of character with Old Town. It was to be the first of many losing votes.

As a candidate for mayor she was endorsed by former mayor and state Sen. Patsy Ticer (D-Alexandria). She raised far less money from developers than Euille or Donley and made a point of returning two donations from real estate entrepreneurs, saying she had decided not to take money from people who do business with the city and thought the entrepreneurs might have projects that would require them to go before the council.

Both the developer contributions and the pace of new building seemed to be on the minds of many voters Tuesday, along with a strong sense that it was time for a new face in the mayor’s office.

“I feel like Bill Euille had his time,” said Patrick Bolton, who was voting at Agudas Achim Congregation, in Silberberg’s home precinct. “Kerry Donley has done a great job, too. But it might be time for a new person.”

Donley voter Linda Pipilo, who has lived in Alexandria for 13 years, said she’s just not happy with how things are working in her city. “A lot of the green spots are gone. . . and traffic is a mess,” she said, adding that she wanted “anybody but Euille” to win.

“Donley and Euille? Been there, done that,” said Cathy Melanson. “A lot of us would like to see a change.”

Daniel Powers, 19, unlocking his bike at Mount Vernon Community Center after voting Tuesday afternoon, said he, too, voted for Silberberg. “She’s much less — how can I say this — ‘same old, same old,’ ” he said.

Euille, who lost a crowded primary race for Congress last summer for the seat won by Rep. Don Beyer (D-Va.), pointed to his accomplishments over four terms, which include passing a plan to redevelop the waterfront, identifying a site for the Potomac Yard Metro station, adding affordable housing above a fire station at Potomac Yard and luring the National Science Foundation to Alexandria from Arlington.

In Arlington, Cristol and Dorsey edged out Peter Fallon for the nomination to fill seats being vacated by long-serving Democrats Mary H. Hynes and J. Walter Tejada, winning 23 percent and 22 percent of the vote, respectively. The other candidates — Andrew Schneider, James Lander and Bruce Wiljanen — finished farther behind.

At least two independents, former Green Party candidate Audrey Clement and former Republican candidate Michael McMenamin, have already announced that they will oppose the Democratic nominees in November. It is the first time in 30 years that two seats on the five-member board have been open at the same time.

All six Democrats vowed during the campaign to be good fiscal watchdogs for the county, a nod to the surprise election to the board last year of John Vihstadt, a Republican who ran as an independent and promised more scrutiny over spending decisions.

Dorsey, 43, is an executive with the Economic Policy Institute who has run for the board twice before. Cristol, 30, an educational consultant, said the board needs to pay more attention to younger voices and to immigrants. Both were endorsed by a coalition of labor and immigrant groups.

Opponents accused Dorsey of being beholden to Vihstadt and to board member Libby Garvey (D), who frequently join together to criticize spending decisions, because Dorsey’s campaign manager previously worked for Vihstadt’s campaign, and Dorsey won Garvey’s straw poll.

But Dorsey denied that, calling himself his own man.

In the Mason District race in Fairfax, Gross characterized Swanson as a political neophyte with few real connections in the district, which stretches from the Falls Church border into Annandale and Camelot.

Swanson based her challenge on two of the district’s most pressing issues: overcrowded schools and a pending redevelopment plan for the traffic-choked Seven Corners area, championed by Gross. She attacked Gross for supporting county budgets that did not allocate the full funding school officials sought and said the plan for Seven Corners would increase density and traffic.

Gross will face independent Mollie Loefler, 45, in the November general election.

In Fairfax’s Mount Vernon District, Storck, a school board member, won 44 percent of the 5,698 votes cast, according to unofficial results. County planning commissioner Tim Sargeant, his closest competitor in the race to succeed Hyland, grabbed 40 percent of the vote.

Storck, 61, focused his campaign on bringing new development to the busy Route 1 corridor, alleviating traffic along that thoroughfare and pushing for more funding for county schools.

He will face Republican nominee Jane Gandee in the November general election.

Elizabeth Koh, Antonio Olivo and Victoria St. Martin contributed to this report.