Limits on the company's charges are set by our regulator Ofwat over a five-year period. The current period is 2010-2015 and the limits were agreed in 2009.

During this period the company is carrying out a major programme of environmental and service improvements across Kent, Sussex, Hampshire and the Isle of Wight totalling about £1.8 billion, at current prices.

The average household bill for 2011-12 is £397, made up of an average water bill of £142 and a wastewater bill of £255.

The scale of service improvements is huge – equivalent to £1,000 for each property in the area.

The improvements will:

• Safeguard water supplies
• Improve water quality
• Protect the environment
• Reduce leakage
• Help prevent flooding
• Cut pollution incidents

Over the next five years, the company will also install nearly 500,000 meters to help drive water conservation and, by 2015, 93 per cent of customers will pay for the actual amount of water they use and have control over their bills.