Located in County Wicklow, Ireland, the Arklow Flood Relief Scheme is critically designed to tackle the persistent and severe flooding problems in Arklow town, which supports a population of 14,000. Historically, Arklow has suffered from significant flooding events, including incidents in August 1986, December 1989, November 2000, February 2002, October 2004, October 2005, January 2010, January 2013, and December 2015. These events have caused extensive damage to both public and private properties and underscore the urgent need for effective flood defenses.
Ayesa, was appointed by the OPW to progress the tendering and detailed design and construction of the Arklow Flood Relief Scheme, a Major scheme aimed at mitigating recurring flooding challenges in Arklow town. Following the successful planning approval granted by An Bord Pleanála in July 2022, Ayesa is now advancing the scheme to its next stage, underscored by a €57 million investment from Wicklow County Council and the Office of Public Works (OPW). Ayesa has undertaken comprehensive hydrological studies and river and coastal modeling, which have informed the preliminary designs and exploration of different scheme options. This work also includes detailed cost-benefit analyses and significant input into the Environmental Impact Assessment Report (EIAR).
Our responsibility extends to managing critical site investigations and surveys across the Avoca River’s extensive catchment area of 652 km², which ranges from north of the Sally Gap to the Irish Sea at Arklow Town. Achievements in this phase comprise an environmental constraints study, an assessment of design options, the emergence and consultation of the preferred scheme, and the finalization of the scheme design and environmental assessment.
In the planning phase, our team conducted the ‘Avoca River (Arklow) Flood Relief Feasibility Study,’ a meticulous analysis to determine the design return periods for river flows and tidal levels. This involved using both gauged and ungauged flood estimation techniques and applying advanced hydraulic modeling tools like HEC-RAS and TeleMac2D. The results were detailed maps depicting potential flood extents, depths, and hazards—critical data for future mitigation strategies.
Our collaborative efforts with other consultants have optimized resources and minimized costs while our design team engaged key stakeholders, including Irish Water, the National Parks and Wildlife Service, the Department of Housing, Local Government, Heritage, and Inland Fisheries. The Public Realm design integrates flood defense walls with the urban and riverine landscape, enhancing both functionality and usability.
The scheme incorporates several ecological enhancements like riverbank extensions, native species planting, and the installation of roosting platforms for birds and bat tubes in bridge arches and flood walls. A significant innovation in this project was Ayesa’s coordination with other consultants, working simultaneously on planned locations to achieve economies of scale. Furthermore, our geomorphology studies supported maintaining a strategic “pinch point” in the Flood Relief Scheme (FRS), ensuring the retention of the existing quay wall. This integration extends the promenade and green spaces, enriching the community benefits and bolstering the area’s resilience against floods.
Ayesa is set to spearhead the tendering and procurement of construction works, enhancing the overall effectiveness of this significant flood scheme through a series of strategic advantages:
Expertise and Experience: With extensive experience in delivering in flood defense projects, Ayesa expertly navigates the technical and regulatory challenges of the project, ensuring adept handling from start to finish.
Technical Proficiency: Our capabilities in hydraulic modeling and flood risk assessments are vital for selecting the right contractors and ensuring the successful deployment of flood defense strategies.
Efficiency in Tendering: Our in-depth knowledge of the project’s specifics streamlines the tendering process, making it both transparent and competitive. This not only benefits the client but also ensures fairness for all contractors involved.
Quality Assurance: Ayesa implements stringent quality control measures throughout the construction phase to ensure that all flood defense structures meet the highest standards of quality and durability.
Optimised Design Implementation: Transitioning from planning to execution, Ayesa maintains consistent involvement to ensure that the flood defense mechanisms are implemented precisely as designed, optimizing functionality and effectiveness.
These strategic approaches guarantee enhanced outcomes for the flood scheme, ensuring robust flood defense solutions that are both effective and sustainable.
Key statistics Population Served: 14,000 residents
Flood Defenses: flood walls and embankments along both banks of the Avoca River
Protection for:
637 residential Properties
141 commercial properties
River Modifications: Dredging of the Avoca River, debris and gravel traps installation, and strengthening of quay walls and Arklow Bridge
Public Realm Enhancements: New urban spaces, footpaths, parking spaces, amenity areas, and lighting along River Walk and South Quay
Arklow Bridge: Underpinning, lowering of bridge floor, and remedial works to masonry
Utilities and Traffic Management: Road reconstruction, traffic calming measures, sewer interconnector for Arklow Wastewater Treatment Plant, and utility diversions
Environmental and Community Considerations:
Roosting Platforms: Installation of bird roosting platforms upstream of Arklow Bridge
