River Grifeen Flood Defence Scheme


Client: South Dublin County Council
Location: Dublin, Ireland
Value: €3 Million
Scope: Catchment management study, detailed design and contract documents



The River Griffeen is a tributary of the River Liffey with a catchment area of approx. 38.8km2. The Griffeen rises in Saggart Hill, 3km to the south of Rathcoole. It is fed by nearby streams and flows northwards joining the River Liffey downstream of Lucan Village. A Catchment Management Study was prepared in 1999/2000. This involved the hydraulic assessment of the entire river and preliminary flood alleviation and planning recommendations. The catchment is predominately rural in the upper reaches and becomes more urban further downstream. Significant development is planned for this catchment. Recent flood events include 1986, 1993 & 2000.

A Report on the flood event of November 2000 was finalised in March 2001. The design criteria for Phase 1 for the mid-catchment was specified by J. B. Barry and Partners Limited and the detailed design was carried out by other Consultants but reviewed and verified by us. The design of Phase II, the lower catchment through Lucan Village, was carried out by J. B. Barry and Partners Limited. This work is now complete. The works involved the regrading of the riverbed, installation and raising of embankments, provision of new culverts and retaining walls and underpinning of bridges and walls.

We scoped and supervised environmental investigations. These were undertaken both prior to and during the construction phase. These included terrestrial and underwater archaeological surveys, ecological studies and on site monitoring by a licenced archaeologist during the construction phase. The project involved significant archaeological works including the restoration of King Johns Bridge - the oldest listed bridge structure in Ireland.