WIRRAL Council and Merseyside Police are appealing to the public to be vigilant following the theft of several drainage grids over the past week.
More than 40 grids have been taken from across the borough, including Leasowe, Moreton, north Birkenhead, Beechwood, Barnston and Gayton.
The missing grids have all been replaced.
Cllr Harry Smith, Wirral Council cabinet member for highways and transportation, said: "These grids are essential, both for safety and to stop large items or a large volume of items, such as leaves, getting into the drainage system.
"It's vital we put a stop to whoever is responsible for taking them – it's not a victim-less crime, every grid that is stolen results in a danger to road users and has to be replaced at additional cost to the council tax payer."
Merseyside Police’s Neighbourhood Inspector for Wallasey, Pete Kolokotroni, said: "An investigation into the circumstances surrounding these incidents is underway.
"The theft of drainage grids can prove dangerous to pedestrians as well as motorists and we are determined to bring the people responsible to justice.
"The community are our eyes and ears and I'd appeal to anyone with information to come forward so we can target those involved.
"As well as 101, people can also call Crimestoppers, anonymously, on 0800 555 111. We will act on any information that we receive."
If anyone notices that a grid has been removed, as well as reporting it to the police, they should call Streetscene on 0151 606 2004.