Preparation of a site specific flood risk assessment (FRA) for the proposed Metro North Depot Site for the Railway Procurement Agency (RPA). The main purpose of this study was to support the Railway Order for the proposed Metro North Dardistown Depot. The FRA was carried out in accordance with ‘The Planning System and Flood Risk Management, Guidelines for Planning Authorities’, published in November 2009 by the Department of Environment, Heritage and Local Government (DoEHLG) and the Office of Public Works (OPW).
The scope of the overall study was as follows:
- Identification and assessment of all possible sources of flooding at the site including fluvial (river) flood risk, tidal flood risk, groundwater flood risk, pluvial flood risk, and flood risk from artificial drainage systems
- Where a flood risk has been identified, to undertake a three stage flood risk assessment as per the FRM Guidelines
- Assessment of flood alleviation measures already in place
- Assessment of potential impact of flooding on the proposed development
- Assessment of how the layout and form of the development can reduce those impacts, including arrangements for safe access and egress
- Review the proposed surface water system to ensure that it is in accordance with sustainable drainage principles
- Assessment of the effectiveness and impacts of any necessary mitigation measures
- Assessment of residual risks to the site after the construction of any necessary measures and the means of managing those risks
The project included the development of an ISIS hydraulic model to determine the effect of the proposed development on water levels and flows upstream and downstream of the development and to determine the storage volume required to mitigate any effects.