Politicians should do more to calm tensions during the marching season, the police have said.
It cost almost £3m to police parades last summer and the bill could be even higher this year.
There are fears dissident republicans may try to cause trouble in some areas, like the Ardoyne in north Belfast.
Police sources told the BBC politicians should work harder to encourage the resolution of contentious parades and reduce the likelihood of confrontation.
While they are hoping for the best, they have to prepare for the worst, which means large numbers of officers and equipment have to be deployed.
The PSNI said it has the resources needed, but also said politicians should do more to defuse tensions.
Senior sources have told the BBC they would like politicians in potential trouble-spots like north and west Belfast, Portadown and Rasharkin, to be more proactive.
The police want politicians to do more to encourage those who want to parade, and those who want to protest, to do so peacefully.