COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

MEETING OF CLONDALKIN AREA COMMITTEE

Wednesday, November 18, 2020

QUESTION NO. 7

QUESTION: Councillor William Joseph Carey

"To ask the Chief Executive to offer a report in response to the following issues. Since completion of the Corkagh Park Housing Development it has been noted that there is height difference of approx. 600mm in the street levels where Cherrywood Crescent aligns with the new estate. What are the implications for child safety where the boundary wall and fence now has a low level access on the side for new houses with high level drop on the existing housing side? Was this envisaged in the original design and what implications does this have for possible flooding in the area?"

REPLY:

(a) Wall design and construction

In accordance with planning, the wall at Cherrywood Crescent was constructed to close the existing access into the adjacent park and ensure that Cherrywood Crescent would remain a cul-de-sac. The planning condition requirement governing this was to liaise with stakeholders including the local residents and South Dublin County Council (SDCC) to agree boundary treatments. The subsequent design of the wall and railings between Corkagh Grange and Cherrywood Crescent was finalised based upon the discussions between all parties. The wall and railings have been constructed in compliance with the agreed design.

In relation to the height of the constructed wall and vertical railings at 1550mm, these are not considered to be readily climbable by children and are largely consistent with other boundaries in the vicinity. These are compliant with the details agreed with local residents and SDCC. The finished street levels on the Corkagh Grange side of the boundary are a result of detailed design of the entire site including surface water drainage and pavement build-up requirements.

(b) Flood risk

A flood risk assessment was completed on behalf of South Dublin County Council (SDCC) at the preliminary design stage of the project. The study includes the following conclusions:

• The risk of flooding on the proposed development site has been considered using available primary sources of flooding information.  This assessment demonstrates that the entirety of the site is not at risk from flooding from either a 1 in 100 year or a 1 in 1000 year storm event.

• The flood risk assessment maps contained within the Catchment Flood Risk Assessment and Management (CFRAM) Study indicate the predicted extent of flooding during a 1 in 100 year and a 1 in 1000 year storm event.  These maps indicate that there is no realistic risk of flooding on the site.

The drainage design for the Corkagh Grange development has been developed in accordance with Sustainable Urban Drainage System (SuDS) design principles, which is mandatory and applies to all new developments.  Compliance with these design principles ensures that surface water run-off from a new development will mimic the run-off that exists in the greenfield state, the run off has been designed to remain within our boundary therefore there is no risk of flooding into adjacent developments.

The surface water drainage system disperses rainwater from the pavement via appropriately designed carrier drains through an attenuation system before discharge into the final drainage connection. John Sisk & Son, the Works Contractor, has confirmed that the surface water drainage system has been designed and installed in accordance with the planning and construction requirements.