What California needs to stave off disaster in its homeowners insurance market is a disaster plan.

That's the conviction of both members and observers of the insurance industry, including California Insurance Commissioner Chuck Quackenbush. Gov. Pete Wilson last week signed into law a couple of bills passed by the state Legislature in the last hours of its 1995 session that address at least interim solutions to the crisis related to coverage for earthquake damage.One, Assembly Bill 1366, would lower the liability for insurance companies, which under current state law are required to offer earthquake coverage to their homeowner policyholders.

The bill limits quake coverage to the basic dwelling unit, omitting accessory structures such as swimming pools and block walls.

It also establishes a 15 percent deductible and $1,500 in additional living expenses. Coverage on the dwelling's contents will be limited to either $5,000 or 10 percent of the structural losses.

The second bill, AB 13, authorizes Mr. Quackenbush to begin preliminary work on his proposed California Earthquake Authority.

The authority, as envisioned by the commissioner, would establish an earthquake insurance pool to be financed partially by insurance companies, as well as by homeowners and investors.

The Association of California Insurance Companies, a trade organization, praised the new legislation as addressing the "dramatic wake-up call for California" represented by the 1994 earthquake. That quake resulted in $12.6 billion in claims by insured homeowners.

More than 90 percent of the companies that did homeowners insurance business in California before that quake have since restricted their sales

because of the requirement to offer earthquake coverage.

The association and others, including Mr. Quackenbush, have said that the best solution to the crisis is a federal disaster insurance program.

But ACIC President Barry F. Carmody said that, "Congress has been unwilling so far to enact such a program. The two bills passed by legislators last month and signed by the governor are not the total solution, but they certainly are steps in the right direction."

Mr. Carmody has called earthquakes "in reality, an uninsurable risk"

because of their unpredictable severity, location and frequency.

"We tend to forget that insurance is not a social program," he said. ''It is a business."

The Natural Disaster Coalition, a Washington-based group backing the Natural Disaster Protection Act now moving - slowly - through Congress, says that unplanned expenditures for natural disaster cleanup threaten any plan for fiscal balance.

Among the points the coalition makes: Before 1989, no disaster costing more than $1 billion had ever occurred or been forecast.

Over the last six years alone, 11 natural disasters each cost more than $1 billion.

Taxpayers already have had to pick up more than $50 billion in disaster assistance, including $16.4 billion in 1994.

The 1995 hurricane season already is the worst since 1934, and experts are predicting an increase in hurricanes and earthquakes over the next 25 years.

Proposed national legislation would create the Natural Disaster Insurance Corp., a private, nonprofit company supported by the insurance industry.

Homeowners with federally backed mortgages at risk for hurricanes or earthquakes would be required to purchase the coverage, and the coverage also would be available to others.