That means all boats, including canoes and kayaks, on 10 reservoirs in Santa Clara County: From this morning’s Mercury News:

Citing the need to protect the local water supply from invasive shellfish that have hitchhiked to California on the bottoms of boats, they have barred all watercraft including canoes, kayaks, water bikes, motorboats and fishing boats.

The ban is expected to be temporary. Water and county officials are exploring a plan to reopen the reservoirs – possibly by Memorial Day weekend. But that idea remains controversial and far from certain: It calls for closing about half of the reservoirs to boaters and starting mandatory watercraft inspections at the rest.

And with an estimated $550,000 price tag to perform inspections to the end of the year, both the water district and county are waffling at paying for them. Officials are considering charging users at least $7 for inspections.

These tiny mussels grow like mad and attach themselves to water pipes, valves and other underwater infrastructure. One water official said that even though the plan for now is to have a short ban, it could become permanent if that’s what it takes to keep the water flowing.