The US government has proposed changing the definition of a showerhead to allow increased water flow, following complaints from President Donald Trump about his hair routine.
Under a 1992 law, showerheads in the US are not allowed to produce more than 2.5 gallons (9.5l) of water per minute.
The Trump administration wants this limit to apply to each nozzle, rather than the overall fixture.
Consumer and conservation groups argue that it is wasteful and unnecessary.
The changes were proposed by the Department of Energy on Wednesday following complaints by Mr Trump at the White House last month.
"So showerheads - you take a shower, the water doesn't come out. You want to wash your hands, the water doesn't come out. So what do you do? You just stand there longer or you take a shower longer? Because my hair - I don't know about you, but it has to be perfect. Perfect," he said.
Andrew deLaski, executive director of the energy conservation group Appliance Standards Awareness Project, said the proposal was "silly".
With four or five or more nozzles, "you could have 10, 15 gallons per minute powering out of the showerhead, literally probably washing you out of the bathroom," he told the Associated Press news agency.
"If the president needs help finding a good shower, we can point him to some great consumer websites that help you identify a good showerhead that provides a dense soak and a good shower," he added.
David Friedman, vice president of advocacy at the organisation Consumer Reports, said showerheads in the US already "achieve high levels of customer satisfaction", while saving people money.
The proposal could face court battles if it advances, Reuters news agency reports.