Why does a company with profits of £150 million that has given £92 million back to its shareholders this year need to hit its customers with an extra thirty quid on their bills?

The answer, Thames Water says, is a mixture of factors they could not have foreseen and the vagaries of the way the industry is run.

Read: Thames Water cite 'unquantifiable costs' for surcharge

Charges from the Environment Agency have gone up they say, they have had to spend huge amounts on a new controversial "super sewer," and they are losing more to bad debt, with consumers not paying up.

The way the water industry works has led to this slightly odd situation where Thames Water and all the other companies essentially have to agree their prices with the regulator years in advance.

If they don't or can't keep costs under control in the way they had predicted then they have to do what Thames has done and ask for permission to put prices up.

But the Consumer Council that looks after our interests believes the scale of Thames' request is not merited.

It is now up to Ofwat to rule on whether the company, owned by private equity, can charge its millions of customers the extra cash.

And the move brings more attention to an industry that has suffered recent criticism for putting the interests of shareholders ahead of consumers.

Read: Ofwat boss voices concern over water profits

More: Thames Water in tax row