A plan by landowners' Frederic and Jennifer Lin to build 51 custom homes in Pleasanton's southeast hills was scuttled Tuesday when voters strongly rejected a development plan for their project called Oak Grove.

Only 45.7 percent of voters supported Measure D which would have allowed the project and 54.3 percent opposed it.

With all 44 of the city's precincts counted, votes against the measure totaled 6,065, well above the 5,104 votes in favor of the project with only a simple majority needed to settle the issue.

Pleasanton has more than 38,000 registered voters.

Supporters said the development is within the city's urban growth boundary and is designated residential in its general plan. The plan would have created 51 lots for luxury custom homes on a 562-acre site and had been approved by the City Council.

Supporters said the home sites were designed to fit within the existing trees and topography, shielding most of the homes from view and eliminating the need to remove oak trees and provide nearly 500 acres of open, natural, parkland and protect the most visible ridgeline in perpetuity.

They also said it would bring increased tax revenue to the city.

But opponents said the development would have violated the spirit of Measure PP that was passed in November 2008 that imposed new ridgeline protections.

They said voting against Measure D was the final step to protecting the natural beauty of the city's hills.

"I think it's time to celebrate that the will of the people has been duplicated in Oak Grove," said Kay Ayala, chairwoman of the "Save Pleasanton's Hills" citizens coalition.

Referring to Measure PP, which bans hillside development, she added: "This ends the development of housing on ridges forever. It's done."

But Councilwoman Cheryl Cook-Kallio, who supportedthe Oak Grove development, said she was disappointed by the results.

"I'm disappointed that you can go into a corraborative process as we did and approach it in an honest manner and have people not see the big picture," Cook-Kallio said. "But the vote's a vote and we go back to the drawing board."

Going forward, she said the City Cuoncil will have to wait for the Lins to bring something different in for consideration, which could be another 10 years or so.

"We have the housing cap issue before us and there are all sorts of other issues out there that need to be considered," she added.

Only one real Assembly race

Pleasanton is divided among three Assembly Districts but only one – the 20th District – had a real race in Tuesday's Primary, with two contenders facing off to run on the Democratic ticket in November to succeed termed-out Assembly Majority Leader Alberto Torrico, also a Democrat.

The lead of Fremont Vice Mayor Bob Wieckowski remained strong all night, and he ended up winning the Democratic nomination with 53.3 percent of the vote over Ohlone College Trustee Garrett Yee. On the Republican side, Adnan Shahab had no competition.

The 20th District has 25 percent of Pleasanton's voters; the 15th District, 15 percent; and the 18th District, 60 percent.

In the 15th District, Assemblywoman Joan Buchanan (D., Alamo) was unopposed, as was the Republican candidate, San Ramon Mayor Abram Wilson.

Also, in the 18th District, Democrat Assemblywoman Mary Hayashi, a Hayward resident, had no opponents in Tuesday's primary, while the Republican candidate, Michael Havig, also ran unopposed.

Incumbent Democrat State Sen. Ellen Corbett did not face any opposition either. Republican Rob Maffit was unopposed for his party's nomination as was American Independent candidate Ivan Chou.