Overview 

The Arklow Flood Relief Scheme situated in County Wicklow Ireland represents a crucial initiative in flood prevention for Arklow town with a population of 14,000. Addressing persistent flooding issues, this project aims to safeguard the town from potential flood risks through the implementation of diverse defence measures, such as flood walls, embankments, and river channel improvements. Additionally, vulnerable businesses will be relocated to enhance overall resilience.

With an investment of 57 million euros, the Arklow Flood Relief Scheme will be delivered in partnership between Wicklow County Council and the Office of Public Works. Wicklow County Council and the OPW, appointed Ayesa to advance the detailed design and construction phases to ensure the project's success. This partnership leverages the expertise of Ayesa and signifies a proactive approach to tackling the persistent challenge of flooding in the region. Read more here: 

Our Role

Wicklow County Council and the OPW appointed Ayesa as the lead engineering consultant in a role that has spanned the Planning & Feasibility phase and now the commencement of procurement for construction works in the coming months. 

In the planning phase, our work included hydrological studies, river and coastal modelling, preliminary design, scheme optioneering and development, and cost-benefit analyses. Ayesa led the planning stage design including the engineering drawings, and the Construction Environmental Management Plan and contributed to The Environmental Impact Assessment Report (EIAR). Throughout the preliminary and planning stages, we managed site investigations and surveys, a requirement for every project phase. The Avoca River and its many tributaries drain a relatively steep catchment of 652 km2 extending from just north of the Sally Gap and flowing southwards, discharging to the Irish Sea at Arklow Town. This study addressed the flood risk of Arklow Town and required a preliminary design of appropriate flood mitigation measures. Following these studies, Ayesa identified a suitable flood relief scheme for Arklow Town, based on technical, socio-economic, and environmental criteria.

Solution 

Ayesa conducted the 'Avoca River (Arklow) Flood Relief Feasibility Study,' a comprehensive examination that involved determining design return period fluvial flows and tidal levels in the Avoca River at Arklow. Design flows were calculated using a combination of gauged and ungauged flood estimation techniques, while design tide conditions were sourced from the Irish Coastal Protection Strategy Study (ICPSS) Phase II Study (DCMNR, 2006), funded by the Department of Communications, Marine, and Natural Resources.  Hydraulic modeling, employing HEC-RAS and TeleMac2D Hydraulic Models, was employed to predict flood profiles in the study area under various tidal and fluvial flood conditions for both existing and proposed flood relief scenarios. This modeling facilitated the computation of the longitudinal flood profile, providing data for the preparation of flood inundation maps across different return period flood events. Flood Extent, Depth, and Hazard maps were then generated for both fluvial and coastal flood risk assessments.  Throughout the planning phases, we collaborated with other consultants working in common locations, allowing for economies of scale and project savings.

The Planning Stage design has been completed, culminating in full planning permission from An Bord Pleanala in May 2022.  The project is now entering the Tendering and procurement of a contractor to deliver the scheme.

Leading the Tendering and Procurement of Construction Works
Ayesa is overseeing the tendering and construction phases, which provide substantial value to the project:

1. Expertise and Experience: Ayesa, as a lead engineering consultant, has significant expertise and experience in flood defence projects. This knowledge ensures a thorough understanding of the technical requirements, regulatory compliance, and best practices in flood mitigation.

2. Technical Proficiency: Ayesa's proficiency in hydraulic modeling, flood risk assessments, and engineering design contributes to the precision and effectiveness of the tendering process. This technical competence is essential for selecting the most qualified contractors and ensuring the successful implementation of flood defence measures.

3. Efficient Tendering Process: Ayesa's involvement streamlines the tendering process by leveraging their knowledge of the project's intricacies. This efficiency benefits both the client (Wicklow County Council) and potential contractors, fostering a transparent and competitive bidding environment.

4. Quality Assurance: Ayesa's oversight during the construction phase ensures adherence to the highest quality standards. Their expertise allows for effective quality control measures, reducing the risk of construction issues and ensuring that the implemented flood defence measures meet or exceed the specified requirements.

5. Optimized Design Implementation: With Ayesa leading the detailed design and construction phases, there is a seamless transition from the planning stage to implementation. Ayesa's familiarity with the project from its early stages ensures that the designed flood defence solutions are accurately and efficiently translated into construction activities.