Also effective next July, residential bathroom faucets will have a maximum flow rate of 1.2 gallons per minute.
New regulations approved by the California Energy Commission mean shower heads sold in California will be limited to spraying 2 gallons per minute beginning in July 2016.
By 2018, they’ll be limited to just 1.8 gallons per minute — the toughest standard in the nation.
Existing regulations limit California shower heads to 2.5 gallons per minute.
More details here.