Clohamon Weir, Slaney River Valley SAC

EPA data on Hogg Enterprises (pig farm)

AIE to IFI: list of all barriers to fish migration removed from Irish rivers in 2021-22,and barriers planned for removal in 2023


In 2021-22 IFI removed and replaced 4 culvert barriers to fish migration. This involved removing historic concrete pipe culverts and replacing them with clear span bridge. Facilitating unimpacted fish passage through the culvert. This was done in collaboration with the local county councils.


There are 2 projects listed under barrier mitigation that were completed in 2022. They are Ballinacarrig and Owenglen. A fish pass was installed at Ballinacarrig and a fish pass was repaired on the Owenglen.

2021 Ops Dev sheet also listed one barrier mitigation project at Castlerea. While the project was completed in 2021, the barrier was actually removed in 2018.

In summary; no barriers to fish passage were recorded as removed by IFI in the Ops Development reports in 2021 or 2022

River Boyne Catchment Management Programme – Martry Weir Fish Pass planned for 2023 (rock ramp)

Bowston weir removal project

South Cumbria Rivers Trust project to remove Bowston weir, on the River Kent at Bowston near Burneside in South Cumbria. It is funded by the European Agricultural Fund for Rural Development.

Noteworthy project due to the level of transparency on the project

IFI Funded Projects (2021)

2021 funding call grants for the SSTCPF and MFF Schemes

Brett’s Weir, Nore, Kilkenny

The GPS location is (653017.096, 654659.02m)

The weir is still in use with water being abstracted to generate electricity which is used to power a saw mill with the remaining power being sold to the grid. The water in the headrace is used to power a generator which I turn generates power for this sawmill.

The River Nore is an important salmon river. The weir at Brett’s causes a delay in fish moving upstream to reach their spawning grounds. This delay can have major problems for individual fish and the species population due to predation, loss of eggs, loss of available spawning gravels, and overuse of spawning gravels downstream of the weir.

Tender: Brett’s Weir – The Construction of a Rock Ramp Fish Pass at Brett’s Weir on the River Nore, Co. Kilkenny.

Dawros River Catchment Management Plan

Dawros River in Letterfrack, more commonly known as the Kylemore River locally.

  • request management plan

River Deel at Askeaton

€105,000 in funding for the preparation of detailed reports and design for the removal or improvement of fish passage at four weirs on the River Deel at Askeaton. Plan will open up 40 kilometres of main river channel and 100 kilometres of tributaries for migrating fish species such as salmon, sea trout, eels and lamprey.

2021 concerns that salmon smolt are being mangled in the hydro-electric turbine run by the Kingspan Aeroboard company

Riddlestown Stream Rehabilitation (River Deel)

€10,000 to West Limerick Deel Anglers for appropriate assessment screening and detailed in-river habitat management plans. These plans help inform appropriate measures and rehabilitation for salmon and sea trout habitats, which is being proposed as part of the Riddlestown stream rehabilitation works.

Barrier Removal for River Restoration

The EU 2030 Biodiversity Strategy calls for greater efforts to restore freshwater ecosystems and the natural functions of rivers.

Besides calling for better implementation of existing legislation on freshwater, the Biodiversity Strategy sets the target to make at least 25 000 km of rivers free-flowing again by 2030, by removing primarily obsolete barriers and restoring floodplains and wetlands.

This document aims to support Member States and other actors involved in river restoration as they seek to achieve this target. The document seeks to clarify the terms and concepts of the target and its objectives, while recognising the need for such definitions to be translated into operational terms. It also provides general principles, and examples of existing approaches and methods that could be used to select and prioritise barriers that would need to be removed in order to reach the target of at least 25 000 km of free-flowing rivers in the EU.

Finally, the document sets out an overview of the different EU funding mechanisms that could support river restoration projects.

The notion of ‘free-flowing rivers’ is not defined in the existing EU environmental legislation.

Based on scientific definitions available, the Commission interprets ‘free-flowing rivers’ to mean rivers or other surface water bodies (e.g. lakes) that are not impaired by artificial barriers and not disconnected from their floodplain.

Given the characteristics of Europe’s river network, the high population density in some areas and the multiple demands on EU waters for different services, it would be very difficult to remove artificial obstacles along a river’s entire course.

This would also likely be incompatible with the maintenance of important river uses. The Commission thus intends to focus on stretches of rivers that can be restored to a free-flowing state, for the benefit of related habitats and species.

While in scientific terms full connectivity of a river system has four dimensions (longitudinal, lateral, vertical and temporal), the Commission proposes to focus efforts on barriers to longitudinal and lateral connectivity of river systems, as more experience and knowledge is available on these two dimensions.

Furthermore, the Biodiversity Strategy calls for a focus primarily on ‘obsolete barriers’, namely barriers that no longer fulfil their original purpose or are no longer needed. As regards the restoration of floodplains and wetlands, other complementary measures should be envisaged besides restoring lateral connectivity through the removal of artificial barriers. Such complementary measures could include, for example, re-meandering, restoration of oxbow lakes and restoration of riparian vegetation.

Altogether, the target of restoring rivers to a free-flowing state is designed to support and find synergies between efforts to achieve the Water Framework Directive objectives and the EU Birds and habitats Directives, with the overarching aim of boosting the restoration of freshwater ecosystems.

To combine the need for urgent action towards the 2030 target with a pragmatic and systematic approach, the document calls for efforts to be undertaken (or continue to be undertaken) to remove artificial barriers, wherever such opportunities exist, on the basis of current knowledge and experience.

In parallel, it is necessary to develop a set of harmonised criteria, according to which river stretches could be defined as free-flowing and thus count towards the 2030 goal.

This could be the subject of a joint process in which the Commission and the Member States work to achieve a harmonised approach at EU level.

Many restoration projects have already been implemented or are ongoing, and a number of existing methodologies can help prioritise sites in each Member State with a view to reaching the target. The document provides an overview of these methods and sets out some general principles for such prioritisation. These include the need to seek synergies with existing legislation or strategies, including with those applicable to protected areas and migratory species’ migration routes (e.g. in connection with the Eel Regulation and the Pan-European Action Plan for Sturgeons). They also include the need to consider existing uses, maximising co-benefits and avoiding as much as possible significant adverse effects on sustainable uses.

Furthermore, good prioritisation and planning of action require robust data. In this context, actions to fill gaps in knowledge (e.g. on barriers’ mapping) can be undertaken in parallel, to support not only the achievement of the Biodiversity Strategy’s target but also a better implementation of EU legislation in general.

The document also provides an overview of the main EU funding instruments that can support river restoration projects. Member States are encouraged to consider such funding sources when planning for river restoration. They are also encouraged to integrate water-related objectives into relevant sectoral planning instruments (e.g. European Maritime Fisheries and Aquaculture Fund national programmes, CAP plans) to ensure appropriate financing for river restoration projects.

Wicklow Bridges Project – Assessment of the risk of barriers to migration of fish species in County Wicklow

IFI Report (2012)

To carry out an ecological survey of a selection of Culverts and Bridges in the County for which there are most likely to be fish/mammal passage problems or other impediments for wildlife.



Where barriers impede or block access of migratory fish to large portions of catchments a direct reduction in the production potential of these systems results. Biodiversity and associated economic value suffer as a result.

• European Eel stocks are currently outside safe biological limits – obstacles to migration in river systems were identified as one of several factors causing this dramatic decline.

• Species such as the Atlantic salmon, River Lamprey and Sea Lamprey are listed under Annex IIa and Va of the Habitats Directive. The Habitats Directive defines certain types of natural habitat and certain species which are seriously threatened as having priority in order to favour the early implementation of measures to protect them.

• The Standing Scientific Committee on Salmon’s report The Status of Irish Salmon Stocks in 2011 with precautionary Catch Advice for 2012, includes information on Irish salmon stocks, the current status of these stocks relative to the objective of meeting biologically referenced “Conservation Limits” and the catch advice which will allow for a sustainable harvest of salmon in 2012 and into the future. According to this report a number of Wicklow Rivers are failing to achieve their Conservation limits, these include the Avoca, Slaney, Vartry, Liffey and Dargle.

• “In Ireland, the Water Framework Directive Freshwater Morphology Programme of Measures and Standards identified barriers to fish migration as one of the principal issues placing channels “at risk” in terms of failing to achieve good or high status as required under WFD” (Gargan et al, 2011).

Wicklow Bridges Project Findings

• Assessments undertaken as part of the Wicklow Bridges Project confirmed numerous impediments to fish passage on watercourses throughout County Wicklow. The scale of the problem in the Avoca catchment alone is highlighted in Figure 4. This map demonstrates that approximately 50% of the entire catchment is potentially impaired (fish migration partially or fully blocked).

• The assessments undertaken through the Wicklow Bridges project represent an important step in the process of establishing a comprehensive baseline of barriers to fish passage in the Eastern and South Eastern River Basin Districts.

• We believe that the works recently undertaken at Mullyclagh Bridge, (Figures 15-17) demonstrate a relatively simple solution to fish passage issues at most existing scour protection aprons. We understand that the cost of the works undertaken at the Mullyclagh Bridge site were in the region of €5000. We would be hopeful that many of the fish passage issues highlighted at smaller bridge and culvert sites could be rectified with similar solutions when routine bridge repairs/maintenance operations are being carried out by relevant authorities (Wicklow County Council or the National Roads Authority).

• The size and scale of the works required for the provision of solutions to fish passage issues at larger bridge/weir/dam sites means that the associated costs are likely to be far higher and unlikely to be included within the budget of bridge maintenance/repair works. The costs associated with larger projects mean that these works will often require specific funding which in many cases may be prohibitive.