COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

South Dublin County Council Crest

MEETING OF LUCAN/PALMERSTOWN/NORTH CLONDALKIN AREA COMMITTEE

Tuesday, February 23, 2021

MOTION NO. 16

MOTION: Councillor P. Gogarty

That the Chief Executive schedules works to be carried out to remove river waste and sediment that has collected beside and reduced the capacity of river culverts in Griffeen Valley Park near areas that flooded in the past prior to remedial works being carried; with rainfall levels increasing due to climate change, lower footpaths regularly unusable and lamp posts in the park close to being under water, these measures appear necessary to avoid unnecessary flood risks.

REPORT:

The screens and channels are monitored and cleared regularly and especially before forecast rainfall events and when flows subside after rainfall events.  

The Griffeen River has been running high during most of January and into February following higher than average rainfall.  Drainage Operations have kept all channels flowing and cleared screens as necessary over this period.  Note Met Eireann records for January at their station in the Griffeen catchment at Casement indicate that there was 95.8mm of rainfall in January against a January mean of 63.8mm, ie this years rainfall for January was 50% over normal.  This has led to the ground being saturated in the catchment.

South Dublin County Council carried out flood alleviation projects on the Griffeen over the past 15 years, which included some attenuation in the upper and middle catchment, and increases in channel capacity in the lower catchment through Lucan Village and as far as the Liffey.  A design element of these projects was to create areas away from housing and critical infrastructure as preferable areas to pond and attenuate flows and this includes areas in park land.  These projects have worked well in protecting property since their construction.  

Following all significant rainfall events we review the impacts and where remedial works are required we programme these.  We're aware of the photo included with this motion which shows a path in park land under water and this would be an example that will feed in to our review, and options here may include raising or relocating the path to higher ground or locally increasing the channel.