"So it is likely that offenders will find it difficult to successfully sell any stolen grates to scrap metal merchants," she said.
"When these grates are removed from roadsides it not only means a cost to the district's ratepayers for their replacement, but their removal also results in a serious safety risk for vehicles and pedestrians, especially children and the elderly."
Ms Wood encouraged members of the public to report any suspicious activity or if they have noticed missing grates.
"We're asking the public to notify the council if they locate any grates or notice any that have gone missing so we can replace them immediately and avoid potential accidents or serious injuries," she said.
"If you notice suspicious behaviour please take a note of the registration number of any vehicle involved and a description of the people acting in a suspicious manner, and contact the police."
Anyone with information about the stolen grates should call Rotorua police on (07) 348 0099 or 111 if it is an emergency.