HOUSEHOLDERS owe their water companies millions of pounds in unpaid bills as debt levels continue to rise, figures out today show.

Unpaid water bills more than a year old totalled £490m in 2005-06 - up by £30m on the previous year, says regulator Ofwat.

Bills left unpaid for less than a year hit £446m in the year to April, 2006.

That figure increased from £403m in 2004-05 and £380m the previous year.

The Consumer Council for Water said rising debt levels followed last year's sharp increase in water rates.

Ofwat's figures show the industry spent £78m on debt management activities in the last year.

This included sending reminders, plus 8.3m letters warning of possible legal action for non-payment - up 43% on the previous year.

Despite this activity, water companies wrote off £103m of household debt in 2005-06.