What some officials say is the most significant measure in Santa Clara County history to help low- and moderate-income residents find affordable housing will come before voters on Nov. 8.

Measure A, a $950 million bond measure, would provide funding to acquire or improve an estimated 5,000 affordable-housing units and provide assistance to 1,000 first-time home buyers, according to the county.

If voters approve the measure, the county would sell bonds in three phases through 2026. Property owners would pay an estimated $12.66 per $100,000 of assessed valuation in fiscal year 2017-18, the first year of the bond sales, or about $127 for a $1 million property. After the last series of bonds is sold in fiscal year 2025-2026, property owners would pay an estimated $10.76 per $100,000 of property value.

The measure is notable not just for its nearly $1 billion price tag (an estimated $1.9 billion when including the principal and interest, according to the county). It is also groundbreaking for its inclusion of low- and moderate-income individuals and families who might not qualify for aid under other housing programs. ("Low income" is defined as not exceeding 80 percent of area median income; "moderate income" is in the range of 80 percent to 120 percent of area median income, the ballot measure states. The median in 2014 was $93,854, according to the U.S. Census.) Of the total funding, $150 million may be used to provide housing for moderate-income families and individuals, with not more than $50 million for first-time home buyers.

The Santa Clara County Board of Supervisors voted in June to put the measure on the ballot. The funding would be distributed through a competitive bidding process, just like any service contracted in the county, according to county Supervisor Joe Simitian's office. Any agency throughout the county can put in a bid for the funds; the Board of Supervisors will decide whether to approve the allocation.

In Santa Clara County, an estimated 6,560 individuals and families are homeless, according to measure proponents.

The revenue will help make up for lost state funding after redevelopment agencies ended in February 2012, said Erica Wood, chief community impact officer for the Silicon Valley Community Foundation, which is supporting Measure A.

When the program ended, "a major source of affordable-housing funding for communities went away," Wood said.

The Housing Trust of Silicon Valley noted in 2008 that agencies in Santa Clara County received $126.2 million for affordable housing. But by 2013 that figure dropped to $47.3 million per year.

If passed, the measure would enable communities to leverage state and federal matching grants, which could further the measure's impact, Wood said.

But the measure does have its detractors. Mark Hinkle, president of the Silicon Valley Taxpayers Association, said the affordable-housing problem is caused by government over-regulation of builders, which has driven up the costs to consumers and discouraged construction. His organization does not support solving the housing problem by raising taxes on existing housing, he said.

"This is a government solution to a government-created problem," he said.

Instead, Hinkle favors changing zoning laws to allow multifamily housing in some R-1 neighborhoods and building at higher densities.

"Maintain real property rights for owners to build what they want and get rid of the red tape," he said.

Hinkle said that while Measure A would help provide housing and programs for the most needy, it won't reduce the affordable-housing problem in terms of the quantity of housing needed to lower prices significantly enough for low-and moderate-income people. Zoning and building restrictions on developers, he said, keep the costs elevated.

The California Housing Partnership has found that 67,576 additional homes are needed for very-low-income and extremely-low income Santa Clara County renters.

Hinkle also sees flaws in the oversight process the bond promises. A special Citizens' Oversight Committee would review the annual report and ensure fiscal accountability, and an independent external auditor would review the county's spending of bond monies.

But Hinkle thinks that any dissenting vote on the oversight committee would be meaningless because only one taxpayer-group representative is likely to be appointed. And bond-oversight committees have allowed funds to be used for other purposes than what the voters approved in the past, he said.

The more than $250 million San Jose Evergreen Community College District Measure G bond approved by voters in 2010 was supposed to rebuild a run-down, 60-year-old vocational center, among other things, but $22 million was later considered by San Jose City College administrators for a theater complex. The move was branded a bait-and-switch by opponents, including the Silicon Valley Taxpayers Association.

Ultimately, although college district officials discussed redirecting Measure G funds from the project to renovate the college’s career technical education facilities to a media arts center, the money was used as originally planned. The career technical education buildings underwent nearly $12 million in renovations and no media arts center was built, Ryan Brown, public information officer for San Jose Evergreen Community College District said.

Measure A specifically states that proceeds from the bond would be used to acquire or improve real property for the vulnerable populations (including veterans, seniors, persons with disabilities, foster youth and victims of abuse) with, where necessary, supporting mental health or substance-abuse services.

The Board of Supervisors passed an oversight measure on Oct. 4 to strengthen independence by the oversight committee. The nine-member board includes only one member who is an affordable housing and supportive housing professional -- no housing advocates -- and the remainder include an auditor, business professional, representative of organized labor, civic organization member, investment professional, a member of the general public, a member of the State Bar of California and a representative of the Santa Clara County Cities Association who is nominated by the association. In addition, an independent auditor will also be appointed by the Board of Supervisors through a competitive bid.

Measure A needs a two-thirds vote in favor to pass. A Santa Clara County survey of registered voters conducted in March and early April found that close to two-thirds support the measure. Of voters surveyed in District 5, which includes Palo Alto and Mountain View, 73 percent said they would likely vote " yes" to approve the measure.

The measure has the support of more than 100 agencies, businesses, nonprofit organizations, city and county leaders, veterans and seniors groups.

"This measure is the most significant funding plan we have ever had in Santa Clara County. It is designed to make major roads to address this problem," said Palo Alto Mayor Pat Burt, who is one of the signers on the ballot argument in favor of the measure.

Correction: A previous version of this story has been corrected to clarify that although officials discussed using San Jose Evergreen Community College District Measure G money earmarked for the vocational center for a theater complex in San Jose, ultimately the money was not used for that purpose and instead was used for the vocational center.