A deluge of trash is flowing through Oakland’s storm drains and depositing so much litter in San Francisco Bay that regulators are threatening to levy fines if the city doesn’t do something to tidy up.

Despite spending millions of dollars over the years on garbage cleanup, Oakland has the Bay Area’s worst record for limiting the rubbish that pollutes creeks, lakes and the bay, according to the San Francisco Bay Regional Water Quality Control Board.

The flow of waste violates mandates set by the board to reduce storm drain litter this year by 70 percent compared with 2009, a goal that Oakland is far from meeting. If the city is still in violation on the July 1 deadline, it could face fines of up to $10,000 a day.