Local bond measures explained
The answer
A local bond measure is a city or school district asking voters for permission to borrow money now, for a building, road, or other capital project, that gets repaid over the following 20 to 30 years through higher property taxes. The folk-model-breaking fact is that the vote threshold, not the level of public support, is often what decides whether a bond passes: a district needing 55% support passes far more often than one needing two-thirds, even with identical voter enthusiasm.
How it actually works
Local governments can't fund a new school or a water treatment plant out of a single year's tax collections, so they borrow, issuing bonds to investors and promising to repay principal and interest over time. Because that repayment usually falls on property owners years into the future, most state constitutions cap how much debt local governments can take on without direct voter consent, which is why bond measures appear on ballots rather than being decided solely by elected officials.
The vote threshold required varies by state and bond type. Many states require only a simple majority. Others require a supermajority: California required two-thirds approval for school bonds until voters passed Proposition 39 in 2000, which lowered the threshold to 55% specifically for facilities bonds, in exchange for restricting how the money can be spent and adding a citizens' oversight committee plus annual independent audits.1 That trade-off mattered: bond passage rates rose from roughly 60% under the two-thirds rule to roughly 75% under the 55% rule, according to an EdSource analysis of California election results.2 Some states still require two-thirds approval for general obligation debt.
Once approved, a general obligation bond is repaid from the government's general taxing power, typically an increase in the property tax rate applied district-wide, spread over 20 to 30 years to match the useful life of the asset being built. This differs from a revenue bond, which is repaid only from the income the specific project generates, such as toll receipts or utility fees, and usually does not require voter approval at all because taxpayers broadly aren't on the hook if the project underperforms.3
Who holds the power
The governing board, city council or school board, decides whether and when to place a bond measure on the ballot and drafts the ballot language, but voters hold the actual approval power, and the required margin, simple majority or supermajority, can determine whether a popular project succeeds or fails.
Where you come in
The ballot measure text itself, along with official pro and con arguments filed by campaign committees, is public before the election. Most states require a public hearing before a bond measure is placed on the ballot, and post-passage spending is often subject to citizen oversight committee review where such committees are required, as in California. Threshold rules are the single biggest lever in this system, worth checking before you assume a close bond vote reflects a divided public.