Supporters of Measure G declared victory this week, eking out a win with roughly 51% support. While the Los Angeles County charter changes didn’t get as much attention as other high-profile measures on the ballot, make no mistake: This wonky governance reform package may be the most transformative decision county voters have made in decades.

By 2026, the county will for the first time have an ethics commission to regulate conflicts of interest and lobbying and investigate misconduct by elected officials and county employees. This is long overdue for a government with a $45-billion budget and 100,000 employees. A recent investigation triggered by the federal corruption case against former Supervisor Mark Ridley-Thomas found significant problems in the county’s contracting process, prompting investigators to recommend a new ethics and compliance officer and other measures to prevent conflicts of interest.

In addition, in 2028, voters will elect an executive to lead the county government. The position — in effect a county mayor — is also long overdue. For more than a century, L.A. County has been governed by a five-member Board of Supervisors, which was fine when the region had more cows than people. But today the county has a population and geographic footprint larger than those of many states. Imagine trying to run New Jersey with a five-member legislature and no governor.

An independently elected chief executive who can manage departments and make decisions will be clearly accountable to the public. That should motivate progress on long-standing needs such as closing the dangerously decrepit Men’s Central Jail and diverting qualified inmates to rehabilitation facilities; addressing problems in the child welfare system; and providing adequate substance abuse and mental health treatment.

And in 2032, nine members will be elected to the Board of Supervisors, which should allow for more representation of the county’s geography, politics and ethnic diversity. Supervisor Kathryn Barger’s 5th District currently stretches from Los Feliz to Lancaster, for example; it’s an impossible job to understand and act on behalf of communities with such divergent needs.

With a county executive in place, the supervisors’ jobs will change too. The board will primarily be responsible for delivering services to the unincorporated portions of the county, legislating and holding the executive accountable.

This should ensure a better, more transparent government. Countless failures and inefficiencies have never come to light because the county lacked even the most basic checks and balances that are essential to democracy.

This will be a monumental shift for L.A. County that good-government advocates — including The Times’ editorial board — have long been pushing for. Four times since 1962, voters have rejected ballot measures to expand the board of supervisors or add an elected county official. The state Legislature considered bills to make similar changes in 2015 and 2017, but neither got enough support.

Supervisors Lindsey Horvath and Janice Hahn deserve credit for co-authoring Measure G. They recognized that with a popular L.A. city governance reform package already on the November ballot, this year presented a rare opportunity to overcome voters’ historic skepticism about expanding county leadership.

While Measure G clears the way for the government overhaul, many of the details still need to be worked out. A governance reform task force will be appointed in the coming weeks to make recommendations to the Board of Supervisors on how to implement the governance and ethics reforms. This will be crucial in laying the groundwork for success — and ensuring that the special interests that opposed Measure G, including county employee unions, don’t try to weaken or stall the ambitious plans.

County voters finally embraced change. They deserve a government that can deliver on its promises.