The minimum cost of providing a garda presence at the axed Garth Brooks gigs would have been €450,000, according to a policing plan sent to Dublin City Council.
The Herald can reveal that the plan for the ill-fated Brooks shows would have seen 176 members of the force on duty, right up to the rank of chief superintendent.
It includes an option to send the garda helicopter and an armed detective was to have been assigned to the stadium's cash office.
Some 400,000 tickets had been sold for five concerts. However, following a sustained campaign by local residents, Dublin City Council only gave permission for three of the events.
This prompted Brooks to announce he would play all five or none at all. In the end, all of the gigs were cancelled.
The garda bill for Friday, Saturday, Monday and Tuesday was going to be €89,040, while the cost for Sunday night had been set at €91,040.
A total of 2,276 hours of garda cover would have been required on Sunday and 2,226 hours on each of the other four nights.
The rate was set at €40 an hour, the records shows.
The sums did not include the bill for providing private security to supplement the garda presence.
Further costs not included were the provision of barriers at €2,000 each night and fuel for the garda helicopter.
Two mountain bike gardai, working 10 hours each day, would also have been on duty. This cost would have been met by the stadium.
The information - obtained through a Freedom of Information request - is contained in correspondence between An Garda Siochana and Dublin City Council.
The sell-out gigs would have required a chief superintendent and superintendent each night along with seven inspectors, 21 sergeants and 146 gardai.
Gardai normally provide public and non-public policing for concerts, with promoters reimbursing approximately 60pc of the cost after the event.
However, the Herald revealed in March that the promoter of the Brooks gigs, Aiken Promotions, had been told that gardai would not patrol the area around the stadium unless the firm covered the full cost.
Public policing covers the residential area around the national stadium as concert-goers enter the gig, whereas non-public policing takes place inside the stadium.
Former Justice Minister Alan Shatter previously told the Dail that the cost of providing policing for a concert was determined by the number of rostered and overtime hours involved.
Gardai calculated the required hours based on a "risk assessment" of the Garth Brooks events -which had been due to take place between July 24 and 28 last - and the "audience profile", the correspondence states.
"The level of policing as set out is also dependant on a structured security/stewarding system assisting in areas of need outside the stadium," it adds, referring to the need for private security.
This would have involved supervising the "early queuing of patrons at St Joseph's Avenue/St James's Avenue prior to stiles opening and crowd management at Jones Rd post event".
The letter says: "A stewarding presence will also be required on Jones Road for the duration of the event to ensure this street is clear for the exit of fans and crowd management."
The garda inspector who sent the cost details to the council said he had "endeavoured to keep garda costs to resource needs only" and consequently he "required a strong security presence" to assist in the operation.
He said additional security patrolling the streets around Croke Park on the eve of the One Direction concerts in May "was very successful and positively remarked on by residents".
"I would advise that this measure is put in place again," the garda added. He highlighted the importance of "a friendly approach to residents" and discouraging outsiders not to park in areas around the stadium.
The cancellation of the Brooks concerts made international news. It is estimated it cost more than €50m in lost revenue to bars, restaurants and hotels.