I am advised by the Commissioners of Public Works that the Office of Public Works (OPW) is not responsible for the maintenance of the channel in this location. Local flooding issues are a matter, in the first instance, for each Local Authority to investigate and address, and local authorities may carry out flood mitigation works using its own resources or, if necessary, may apply for funding under the OPW's Minor Flood Mitigation Works and Coastal Protection Scheme. This administrative Scheme's eligibility criteria, including a requirement that any measures are cost beneficial are published on the OPW website at: http://www.opw.ie/en/floodriskmanagement/operations/minorfloodworkscoastalprotectionscheme/.
No application under the minor works scheme has been received to date by the OPW for the location referred to in this question.