SACRAMENTO -- California lawmakers are betting that voters eager to avoid a Katrina-style disaster will rally behind a $4.1 billion bond on the November ballot to shore up the state's fragile levees.

While few experts disagree that California needs to rebuild its aging levee system, an Associated Press review of the state's largest-ever flood plan has found the measure requires voters to take a leap of faith that the state will spend the money the way lawmakers have promised.

An extensive examination of the measure, reviews of state and federal studies, and interviews with two dozen water experts, lawmakers and environmentalists have revealed the bond lacks core details about how, when and where the money should be spent.

Without those components, the bond measure fails to answer how soon the hundreds of thousands of residents and the critical freshwater supply guarded by 2,300 miles of river levees might be protected.

In what some experts say is the bond's most open-ended question, it provides little more than a sketch for how the state would rank and allocate billions of dollars for levee projects. At best, experts say, the process would be based on scientific studies but still run the risk of becoming politicized. At worst, it could allow deep-pocketed developers to sway decisions and build even more homes in flood-prone areas.

"The bond is asking for a lot of money and not providing a lot of policy about how that money will be spent," said Mindy McIntyre, a water specialist with the nonprofit Planning and Conservation League, which is pushing lawmakers to prioritize bond expenditures.

The measure's authors say that by its sheer size the bond would go a long way in boosting flood protection and securing the water supply for 22 million state residents from Silicon Valley to Los Angeles -- nearly two-thirds of the state's population.

But even the measure's supporters acknowledge that the process for developing the levee bond, which was hammered out in the hours leading up to a 3 a.m. vote, has left the ballot measure with numerous holes. It provides money without a comprehensive plan for how it is to be spent.

"Does (the bond) put the cart before the horse? You could ask that," said Assembly Budget Chairman John Laird, D-Santa Cruz, who helped craft the plan. "Some of us would have liked to have seen many other decisions taken in tandem with this, but many lawmakers felt it was more important to get the bond out there on the ballot and take advantage of a rare window of public awareness because of the Katrina disaster."

The levee measure is part of a $37.3 billion public works bond package the Legislature placed on the November ballot and that Gov. Arnold Schwarzenegger is supporting as a centerpiece of his re-election campaign. The other three measures would provide billions for transportation, schools and affordable housing.

Among the problems revealed in the AP analysis:

* The eight-page measure provides scant direction for how $3 billion would be spent on levee repairs in the Central Valley, an area stretching roughly 500 miles from Redding to Bakersfield.

* It leaves decisions for prioritizing and financing projects largely up to the governor and lawmakers during the politically charged annual budget process. The process carries the potential for lawmakers to allocate some of the money for pet projects in their districts instead of the levee repairs that scientists deem most effective.

* A five-year levee evaluation, which could determine where development should be curbed and what cities might face higher flood insurance, would be vulnerable to influence by special interests.

* Taxpayer money could be used to benefit developers and homeowners. The bond allows the state to pay off developers and homeowners where it deems the cost of maintaining levees would be too high, but it provides no details for how the state will determine the value of that land.

Schwarzenegger and key Republican and Democratic lawmakers say passing the bond is crucial to reduce the threat of catastrophic flooding.

Studies have shown large parts of the levee system could crumble during an earthquake of magnitude 6.5 or greater, allowing salt water to inundate the drinking water supply for up to three years.

"None of this money will be spent willy nilly or without some formal review," said Assemblywoman Lois Wolk, D-Davis, who helped write the measure. "There isn't enough money in the world to fix the delta, so prioritization is essential. We have to pick the levees where people are most at risk."

As written, however, the bond provides no guarantees. At best, hydrologists, environmentalists and others say they fear the state will lack focus when it's time to spend the money.

McIntyre, of the Planning and Conservation League, said the governor and Legislature must pass laws establishing a framework for spending the money if the public is to feel comfortable with the bond.

Wolk and other lawmakers are pushing a package of bills through the Legislature that would begin to do that. But the lack of detail in the levee bond could create a tough choice for voters, said David McCuan, a political science professor at Sonoma State University.

"Ballot measures have been specific and narrowly targeted to provide tangible benefits," he said. "In November, the ballot measures are not following that playbook. It's a new playbook and an expensive experiment."