http://www.huffingtonpost.com/adam-j-rose/how-to-take-long-s...
http://www.onegreenplanet.org/news/californias-drought-whos-...
"The meat industry consumes over half of all water used for all purposes in the United States. Most of this water is used to irrigate cattle feedlots."
http://darwin.bio.uci.edu/sustain/global/sensem/MeatIndustry...
Looking at a source from the HuffPo article (http://pubs.usgs.gov/circ/1405/pdf/circ1405.pdf), I can see 188 million gal/day used in livestock in California, while a staggering 23,100 million gal/day is used for irrigation.
So no, giving up meat would not really help with the Californian drought. It is true that meat consumes a bunch of water, but that is a drop in the bucket compared to the agricultural use.
"By far, the largest component of beef’s water footprint is the huge volume of virtual water consumed by cattle through their feed, in this case both forage and grain."
http://www.news.cornell.edu/stories/1997/08/us-could-feed-80...
Water required to grow the feed for a Holstein Cow: Corn 30,208 L, Alfalfa 201,004 L