People living in the SN25 postcode area in Swindon have been left without water - or having to cope with low pressure.
It is due to a burst water main on Thames Avenue.
Households in parts of Wiltshire could see water bills rise by more than 10 per cent above the cost of inflation - but elsewhere in the region they could drop by around six per cent. Thames Water wants to make the increase to pay for a new sewer in London.
By contrast Wessex Water says its bills will fall in real terms from an average of £479 a year now to £454 by 2020.
Thames, which pays no corporation tax, last week announced half-year pre-tax profits were up by nearly a fifth to £134.2 million, helped by an above-inflation tariff hike. It is already at loggerheads with the regulator over customer charges.
Thames serves 14 million customers in and around London. It said its current typical £358 bill is £50 below the average for England and Wales but would increase to £398, plus inflation, for 2020.
Last month it was slapped down by Ofwat over plans for a one-off £29 bill hike for next year, because of unforeseen costs including customers failing to pay their bills, as well as the Thames super sewer.
The water regulator, Ofwat, may block a proposed £29 surcharge on bills for thousands of customers in Gloucestershire and Wiltshire.
Thames Water wants to impose the levy next year - on top of its annual price increase, to pay for a new sewer in London and to cover the cost of bad debt.
Ofwat is now challenging the need for the increase, a move welcomed by the consumer watchdog.
Sir Tony Redmond from the Consumer Council for Water said he was encouraged the regulator had taken this decision:
Thames Water wants to increase prices for customers in the West to help pay for a new super sewer in London.
The company, which supplies water to parts of Wiltshire and Gloucestershire, has applied to regulator Ofwat to add an extra £29 onto every household's bill. Thames Water says the company is facing a tough time financially even though its revenues rose to £1.8 billion in the last financial year.
The Consumer Council for Water has expressed disappointment over Thames Water’s plans to increase its prices next year. The company’s proposals could see the average water and sewerage bill in the Thames area (including parts of Wiltshire and Gloucestershire) increase from £354 to almost £400.
The company says the rise is to cover a rise in bad debt, costs associated with the 2011 transfer of private sewers to company ownership, and land purchase linked to the Thames Tideway Tunnel.
Thames Water has issued the following statement after 900 homes in the Cirencester area were left without water yesterday.
Almost all the Thames Water customers who have been without water in parts of Cirencester have now had their service restored. 900 homes lost their supply after power spikes at a pumping station.
Some are still affected by one or two airlocks but the company is confident they will be back on line soon.
Hundreds of people in parts of Cirencester are currently without water. It's due to a problem with Thames Water. The company is working to fix it and is handing out bottles of water.