LOS ANGELES (CBSLA.com) — The Los Angeles County Board of Supervisors has approved a conservation plan which will assess doubled — not tripled — charges for some water customers.

Residents in the Antelope Valley, Malibu and Topanga Canyon could face big penalties if they fail to meet targeted consumption cuts of more than 30 percent on average.

READ MORE: CHP Issues Sig Alert After Fatal Crash On 101 Freeway

Some opponents have complained that the plan – which would require cuts as high as 80 percent for some households – could unfairly impact big families and those already taking steps to curtail their water consumption.

READ MORE: Street Closures From Electrical Pole Fire In Redondo Beach Lifted

The vote coincided with a report from state regulators that several Southern California cities including Los Angeles and San Diego continued to lag in conservation, cutting just 9 percent compared with a 13.5 percent reduction by the rest of California in April.

The State Water Resources Control Board announced it will start tracking compliance this summer after assigning each community a water use reduction target of as much as 36 percent. The board is also tracking how local agencies crack down on water waste.

MORE NEWS: Lancaster Shooting Leaves One Wounded

(TM and © Copyright 2015 CBS Local Media, a division of CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)