An organised gang is believed to be behind the theft of 70 drain covers in parts of Lincolnshire.
North Lincolnshire Council first noticed the covers missing on Friday and more were stolen at the weekend.
The thefts, costing tax-payers around £30,000, have left gaping holes and are endangering the lives of road users.
Chevrons used to warn motorists of dangerous bends have also been stolen. It was thought the covers were being sold for scrap metal.
The thieves have taken gully covers from Burton, Normanby, Wressle, Epworth, Luddington, Wroot, Crowle, Belton, Westwoodside and Eastoft.
The local authority say they cannot replace the lids of the drains without replacing the whole unit, which means digging up the road and causing an inconvenience to drivers.
Councillor John England, Cabinet Member for Environment and Transport at North Lincolnshire Council, said: "These idiots are putting people's lives in danger.
"Removing the gully covers and chevrons is a stupid thing to do and is costing taxpayers thousands to put right.