LOS ANGELES  Fri Apr 10, 2015 3:32am BST

Los Angeles Mayor Eric Garcetti launched a "Save the Drop" campaign on Thursday, seeking to rally residents of California's most populous city behind water-saving measures in the face of a devastating, multi-year drought.

The public relations push comes as state officials tighten already strict rules on water usage and ask cities and towns across California to enforce a 25 percent reduction in water usage before the hot, dry summer season begins.

California is entering its fourth year of a severe drought that has left mountain snow pack, which generally provides about a third of the state's water, at its lowest level on record and forced farmers to fallow thousands of acres of cropland.

In Los Angeles, Garcetti's campaign implores residents of America's second-largest city to save water with ads on buses and trash trucks and an educational programs at libraries and alerts them to programs such as rebates for replaces water-gulping grass lawns with drought-tolerant plants.

"Because we acted strategically and acted early, we have powerful tools in place to respond to this historic drought," Garcetti said in a statement released through his office.

"Now, through this unprecedented outreach campaign, we are taking action to make sure every Angeleno is informed and encouraged to harness those tools to lower their water use and their water bills,” he said.