Boats return to East Bay’s San Pablo Reservoir with golden mussel inspections

By John Ramos

When the golden mussel was discovered near the Port of Stockton in late 2024, lakes and reservoirs across Northern California imposed new rules on boaters to try to keep the invasive species out.  

EBMUD, the water supplier for most of the East Bay, took no chances, banning all boats from entering its reservoirs. On Sunday, after more than a year, they began inviting boats back to the water, but they’re being very careful about it.

On Sunday morning, the surface of San Pablo Reservoir was glassy smooth. It’s been a while since any boat wakes disturbed the water. Jaime Garcia was fishing from the shore and said he’s gotten used to the peace and quiet.

“As a fisherman, I kind of like it without the boats,” he said.  “But I also understand that people want to come out with the boat, bring their families and fish. So, I understand that too. And I don’t think it makes a difference. The fish are still in the water, whether you have a boat or not.”

But the fish may soon have company out there again, because after a long pause, EBMUD was offering boat inspections to begin the process of allowing them back onto the lake.

“Today is a very big day,” said EBMUD spokesperson Nelsy Rodriguez.  “After a year closure to protect the waters from the invasive golden mussel, we are finally opening up San Pablo Reservoir.”

The reservoir is a key component of the water supply, and the quick-breeding mussel poses a huge clogging threat to EBMUD’s pipes and infrastructure.  So, they waited to see how others were dealing with the problem.

“Many water agencies were trying different methods. There were 15-day quarantines, there were 30-day quarantines. Some weren’t able to put quarantines in place at all and inspections, and over the course of the year, the mussel did spread,” said Rodriguez.

A California Department of Fish and Wildlife map shows how the invasion spread in 2025, with more discoveries in the Delta and Central Valley rivers.  

But EBMUD has decided the most effective action is a 30-day quarantine.  After an inspection to be sure they’re completely clean and dry, boats will be tethered to their trailers with sealed cables to prevent them from being launched. After the waiting period, they will be allowed back on the lake and then, upon leaving, given another sealed tether, specific to San Pablo.

“And then, after that, you can come in and out as you please,” said EBMUD senior ranger Blain Thompson. “But if you do go to another reservoir, you would need to have another 30-day inspection before returning to San Pablo. So, it is kind of decision that boat owners need to make, in terms of where they want to launch their boats for the season.”

It’s changed the way people play on the water. For practicality, boat owners must now pick a spot to use for the summer instead of moving from lake to lake.  Or they could do what Brandon Loyd did and choose a kayak instead.  On Sunday, we watched as he hauled in a three and a half pound bass.

“Spotted bass. They’re in here,” he said, snapping a quick photo before releasing it.

At San Pablo, kayaks can launch without a quarantine, as long as they are first inspected and found to be “clean, drained and dry.”

“This is opening day, so the first day that I’ve been back to San Pablo,” said Loyd. “But I love this place. It’s too bad it’s been closed down for a year, but obviously you gotta do what you gotta do. It’s the right thing to do. Honestly, the process was super smooth and everyone was very professional.”

EBMUD began its inspection process on Sunday at San Pablo Reservoir, but it will wait until May to begin allowing boats on its largest reservoir, Lake Comanche, northeast of Stockton.  

The golden mussel is a serious threat, and officials say most boat owners seem to understand that and accept the new restrictions. So far, EBMUD has avoided the pest, but it only takes one mistake to cause an infestation and there is no way to get rid of them once they arrive.