The council says the South Kerry Greenway was a forerunner of what is now the accepted standard for greenways.
Kerry County Council was responding to issues noted by the Department of Transport, Tourism and Sport in internal documents, which show concerns being raised about the increasing cost estimates.
The estimated cost of the South Kerry Greenway increased from €4.7m in 2014 to €16.1m by December 2015; at last November’s oral hearing, An Bord Pleanála heard the estimated cost is now over €20m.
The proposed 32km greenway runs from Glenbeigh to Renard.
Kerry County Council says the South Kerry Greenway was a forerunner of what is now the accepted standard in terms of surfacing, alignment and gradients.
The department queried the cost increases during 2014 and 2015, as the estimate went from €4.7m to €16.1m.
The council now says no project of this standard and complexity had been constructed at that time, so there were no comparative costs available to the department by which to judge the estimates submitted.
It says that the Capital Infrastructure Unit of Kerry County Council was preparing a project appraisal and cost benefit analysis at that time to ensure that - as the project moved from conceptual to the design stages - figures are updated to reflect the actual costs.
The council says the cost/benefit analysis was subsequently approved by the department.
It adds this analysis highlighted the benefits of the scheme to the South Kerry economy.
The department reviewed the council’s proposals, which stated that the it had ‘examined all possibilities for value engineering the project and that the solution proposed is appropriate’.
In December of 2015, the department said of Kerry County Council: ‘The obvious attention to detail of […] your team gives us great comfort with regard to the cost estimates.’