LOS ANGELES (Reuters) - Los Angeles residents were urged on Wednesday to take shorter showers, reduce lawn sprinklers and stop throwing trash in toilets in a bid to cut water usage by 10 percent in the driest year on record.

With downtown Los Angeles seeing a record low of 4 inches

of rain since July 2006 -- less than a quarter of normal -- and with a hot, dry summer ahead, Mayor Antonio Villaraigosa said the city needed "to change course and conserve water to steer clear of this perfect storm."

It is the driest year since rainfall records began 130 years ago.

The Eastern Sierra mountains, where Los Angeles gets about half of its water supply, marked its second-lowest snowpack on record this year.

That and the lack of rainfall could force the nation's second largest city into full drought mode in coming months, officials said.

Below average rainfall for the past few years has also turned the traditional summer southern California fire season into an all-round event. Firefighters battled two major brush fires in May alone, at the Los Angeles landmark Griffith Park and on the tourist island of Catalina.