Thames Water has reported a big fall in half-year profits, saying extreme weather has hindered its ability to fix leaks and overhaul its infrastructure.
The company said the Beast from the East cold snap had caused pipes to burst, while the summer heatwave had brought supply problems.
Underlying pre-tax profits fell by nearly half to £67.7m, from £129m a year earlier.
It said the weather had had an "enduring impact" on leakage problems.
The firm added that it had received 11,083 written complaints about supply interruptions in the six months to 30 September, up from 8,242 in the same period a year earlier.
Chief executive Steve Robertson said: "During the intense summer heatwave, we worked tirelessly to protect our customers from supply restrictions.
"However, along with the impact of the Beast from the East, it has delayed our progress on leakage and other performance measures."
Since 2017, Thames Water has been fined more than £128m for poor management of leaks.
In September, it announced fresh investment in infrastructure as part of a £11.7bn five-year plan.
The future of the water industry has recently become a hot political issue, with Labour saying it will take it back into public ownership if elected.
Water firms were sold off by the Conservative government of Margaret Thatcher in 1989.