Slane, Co Meath, is to become a "controlled zone" the weekend after next, with everyone and all vehicles entering the area being searched, according to Garda plans for the Slane Castle concert.
The Garda aerial and mounted units will help patrol the crowds. Between 70,000 and 80,000 are expected in the castle grounds for the concert, whose main attractions are The Verve, Robbie Williams and the Manic Street Preachers.
In an attempt to prevent drownings or accidents in the Boyne, which runs alongside the castle, nine boats with Civil Defence and river rescue personnel will be in place and in radio communication with each other.
Supt John Farrelly of the Garda Press Office said: "This will ensure that anyone entering the water will be clearly visible and action will be taken to remove them. There will also be a cordon in front of the river manned by gardai."
Only residents' vehicles with special permits will be allowed into the village after 10 p.m. the night before the concert. Other vehicles on the streets will be removed.
Supt Farrelly said: "The security arrangements are very tight. Slane will effectively be sealed off and it will become a controlled zone. Every individual and vehicle coming into it will be searched and every vehicle will have to have Garda accreditation. We are all conscious of what can happen, given what occurred in Omagh. No one can rule out the possibility that something is not going to happen anywhere."
About 400 gardai will be on duty and a special court will sit in Slane village throughout the day. Gardai are expecting some public order offences. Members of the national and local drug units will mix with the crowd.
A field hospital with six doctors and a number of nurses will be in place. To help control the traffic problem, Dublin Bus is running more than 100 buses from Dublin to Slane and back again that night.