(Wine-Searcher) - Vineyards are a $4.4 billion industry in California, and a major source of tourism. But in one swath of Los Angeles County, there's a law pending that would ban new vineyard plantings.

And it's just vineyards – not avocados, not rutabagas, nor any other kind of agriculture.

Last month, the county Board of Supervisors approved a plan that would ban new vineyards in the Santa Monica Mountains, west of the city of Los Angeles. Most of the estimated 50 vineyards already there would be grandfathered in.

Fortunately for wine lovers, the area – part of a proposed new Malibu AVA – isn't exactly Sonoma County. There are only about 15,000 cases of wine produced annually, and there aren't any well-known names.

But still, the move is surprising in California, where grapes are the second most important agricultural product behind milk.

Don Schmitz, owner of the wine brand Malibu Solstice, is organizing opposition before the Board and the California Coastal Commission issue final approval this summer. Schmitz is not at risk of losing his own vineyards, but he says the move doesn't make any sense.

"Vineyards use less water, less fertilizer and have less environmental impact than other forms of agriculture," Schmitz told Wine Searcher. "The original proposal was to eliminate agriculture entirely. They put ag back in the day before the meeting but they kept a ban on all new vineyards."

The main proponent of the ban is county supervisor Zev Yaroslavsky, who has championed environmental issues since being elected to the board in 1994. 

Yaroslavsky wrote on his blog that the plan "would prohibit new commercial vineyards because of their serious impact on water quality in our streams, beaches and the Santa Monica Bay. The policy prohibiting new vineyards would also prevent the loss of sensitive habitat and avoid concerns over the industrial spraying of pesticides."

The proposal is up for a final vote before the California Coastal Commission in July and, if passed, goes back to the L.A. County Board of Supervisors for final approval.