Thousands of households are set for a £35 bill discount after they were left without water.
The incident happened in the run up to Christmas and was caused by burst pipes.
Some 4,000 homes in Ceredigion, Wales, were affected in December.
Welsh Water has now confirmed customers who experienced outages will receive money off their water bill as compensation.
If your supply was cut off for more than 12 hours, you will be paid £35.
Some families were left without water for several days.
Welsh Water has said additional £35 payments will be made for every subsequent 12-hour period.
If you’re entitled to a payment, the money will be paid automatically to your water account - you don’t need to apply for it.
A spokesperson from Welsh Water said: "Such disruption and inconvenience is rare, and our teams worked tirelessly to restore supplies as quickly as possible."
They added: "We again would like to say how sorry we are for the inconvenience that was caused and hope our goodwill payments reflects this to our customers."
More households are set to see their water cost reduced this year after the regulator Ofwat ordered 11 firms to cut bills.
The suppliers have been ordered to knock a collective £150million off water bills due to "falling short" of its expectations.
Ofwat said these firms had missed its targets on things like pollution, sewer flooding and water supply breakdowns.
Water firms that missed Ofwat's targets, like Southern Water and Thames Water, will have to return money to customers.
The exact refund per household will vary.
But other water firms have the green light to increase bills - such as United Utilities, Wessex Water and South Staffs Water.
The average UK home pays £419 for water over 12 months, with the typical bill rising £4 this year.
Around 1.1million people need help paying these bills, according to trade body Water UK.
This will rise to at least 1.4million by 2025.
Ofwat chief executive David Black said: "We expect companies to improve their performance every year. Where they fail to do so, we will hold them to account."
He added: "All water companies need to earn back the trust of customers and the public and we will continue to challenge the sector to improve.”