Water authorities in the West Midlands are billing some companies in the region by as much as £57,000 - for disposing of rainwater that falls on their properties.
Now valuation specialists in the Birmingham office of property consultancy King Sturge are challenging the validity of the charges following "a flood" of complaints from its clients.
David Evans, who heads up the business rates team in the Birmingham office of King Sturge, said that South Staffordshire Water and Severn Trent were attempting to claim backdated surface water drainage charges for anything up to six years.
"Clients have been issued with bills which range from around £5,000 to amounts up to as much as £57,000," he said.
Surface water is classed as rainwater that falls on to a property and it's surrounding site that drains to the public sewer.
The charge covers the costs of taking away and treating surface water that runs from properties into a sewerage company's drains.
Mr Evans said: "Severn Trent and South Staffordshire Water have been re-surveying properties and we are currently in the process of challenging the amounts they are claiming."