He added: “We need to protect what we’ve got because we are seeing high pressure coming in for the late autumn, which means we can’t guarantee any rain for the foreseeable.”
The ban applies to all customers that Thames Water supplies with drinking water but Muncaster said at the moment they are not taking the “severe step” of putting any bans on businesses.
The CEO of campaign group River Action James Wallace was critical of the ban and called it “outrageous”.
He said the water firm had failed to respond to “decades of warnings about the threats of climate change”.
Wallace added: “Thames Water’s crumbling infrastructure loses a staggering 570 million litres of treated drinking water every day through leaks, exposing years of chronic underinvestment and poor maintenance.”
In response, Muncaster said they are “investing heavily” in infrastructure including a £20bn investment over a five year period to “reduce leaks”.
“We are out there every day fixing leaks. We’re fixing around 750 a week at the moment,” he said.
“I can’t predict when it will rain and recover but as soon as it does we will lift the ban. It’s not something that we want on, but it’s something that we think is the right thing to do at this time.”
He said Thames Water will not be patrolling to enforce the ban but will put its trust in customers to use water responsibly.
Thames Water has confirmed that compensation or bill reductions do not apply for hosepipe bans.