The waters of the Sacramento San Joaquin Delta have been under siege.

Golden mussels a fast growing invader that threatens to choke off water supplies and damaged dams, power plants and ecosystems, started showing up in the delta more than a year ago.

Native to China and Southeast Asia, the mussel may have slipped into the state on a commercial ship, even with shipping rules aimed at keeping invaders out.

I mean, that's almost like bringing, like bedbugs or something back from a trip overseas, you know?

I mean, you you don't mean to do it.

You get stowaways, unfortunately.

Now, water managers are battling to keep the mussels from spreading to uninfected lakes and reservoirs, and they're racing to keep them from damaging pumping plants and other facilities that send Delta water to farms and cities in central and Southern California.

But the state has no specific funding or plans to directly tackle harms right at the center of the invasion.

In the Delta itself.

Last year, California lawmakers set aside $20 million in proposition 4 funds to fight off Golden and other invasive mussels statewide.

The California Department of Fish and Wildlife says the money will support research that could eventually benefit the Delta, but none of it is dedicated to immediate impacts there.

Local leaders and people who live in the Delta fear the stigma of an infestation will drive visitors and boaters away from one of the country's largest estuaries.

The muscles are already encrusting boats, water pipes and irrigation siphons, with potentially devastating consequences for farming and boating in the region.

Scientists agree there's no silver bullet.

Some have pinned their hopes on a chemical compound called Zequanox, originally developed to fight other invasive mussels.

But even the company's founder says a delta wide fix is not likely feasible or cost effective.

For now, there's a growing sense that these muscles are here to stay.

For CalMatters, I'm Rachel Becker.