An invasive species is forcing the closure of Lake Hennessey in Napa County.
The lake is an important water supply for Napa, and it provides about half of the city's drinking water.
The city is closing the lake's boat launch, and banning boats, after 'golden mussels' were found to the north in the Sacramento- San Joaquin River Delta.
There is also a 30-day quarantine program in effect for all boats entering Lake Berryessa.
Any boats that pass through Berryessa will be tagged with a 30-day quarantine sticker. They will not be allowed to launch during that time. This is to prevent the entry of the mussels.
Christie Smith has more in the video above.
Get a weekly recap of the latest San Francisco Bay Area housing news. Sign up for NBC Bay Area’s Housing Deconstructed newsletter.