Annacotty

A barrier is anything that might prevent a fish from passing, migrating or may slow it down on the way up or down a river. Barriers alter river habitats, affecting the physical character and water content. Physical barriers can be natural or man-made features and can include weirs, bridges, waterfalls, culverts, fords, dams, sluices and ramps. Inland Fisheries Ireland has been building a national inventory of barriers under the National Barriers Programme since 2017. An online dashboard by IFI has identified over 7,000 barriers at locations across Ireland. 

The ultimate goal of this pilot project is to improve fish passage at Annacotty Weir on the River Mulkear, helping migration of fish both up and downstream. This project is also a pilot that involves a team of multi-disciplinary panel of internal and external experts. The approach will inform similar future mitigation projects undertaken as part of a national mitigation programme. 

Annacotty Weir has been identified as a significant barrier to the free movement of fish. Barriers to migration can block or delay migrating fish populations and may lead to increased mortality through diseases and predation. Delays in smolt migration may also affect their survival when they enter the sea. 

Annacotty Weir is a high impact barrier to the migration of adult salmon and sea trout and a complete barrier to the migration of sea and river lamprey. To these anadromous species, human-made barriers are considered one of the most pressing threats to existing populations.

To progress the project an Interagency Group for Annacotty Fish Passage Project has been set-up, which includes representatives from Inland Fisheries Ireland, the Department of the Environment, Climate and Communications, the Department of Housing, Local Government and Heritage, Limerick City and County Council, the Office of Public Works (OPW), the National Parks and Wildlife Service (NPWS), the Local Authority Waters Programme (LAWPRO) and the ESB.

Annacotty Weir has been altered on several occasions in the past. In the earliest Cassini maps of Ireland, there are only ‘waterfalls’ marked at Annacotty. A weir in a different configuration is present in the early 1900s maps. The orientation of the weir was altered by the OPW in the mid-1990s to the present arrangement and a Denil fish pass was constructed. 

Mulkear LIFE (2009-2014), an EU Commission-funded project, focused on salmon, sea lamprey and otter in the Mulkear catchment. As part of this project, sea lamprey passage was improved at Annacotty weir through the addition of a plastic egg cup- like climbing substrate (lamprey tiles) attached to the weir face. 

Temporary works require agreement with all stakeholders. As this site is within a Special Area of Conservation this can be a difficult task as all relevant legislation needed to be followed. 

Unfortunately, due to the heavy rain in Summer 2024 works could not proceed under health and safety requirements with proposed temporary measure of refurbishment of the Denil fish pass and to restore the lamprey tile matts on the weir face. Low river flows below the 95th percentile are required to put in place works to proceed.

A Denil Fish Pass was constructed as it was the standard at the time. Current standards require consideration of all species and their differing swimming abilities.

Lamprey Tiles were installed during the Mulkear LIFE project, these have degraded over time and need continuous maintenance. It should be noted that the lamprey tiles only improve passage for sea lamprey and not river lamprey.

The work was carried out under the Ballymackeogh certified drainage scheme. The weir unfortunately was in a state of neglect and needed to be refurbished. 

Inland Fisheries Ireland was funded under the Salmon and Sea Trout Rehabilitation, Conservation and Protection Fund for the Annacotty Fish passage project. This was being used to deliver the technical, engineering, stakeholder engagement and planning elements of the Annacotty project.

Recently government announced funding of €100 million that has been approved for a programme to remove, mitigate and where possible lessen the ecological impact of river barriers on migrating and resident fish species. This is critically important for Atlantic salmon, European eels and lamprey. Over the life of the programme, it is expected that 257 barriers will be mitigated. This funding will focus on mitigating structures in rivers, including bridge aprons, culverts, sluices, fords and weirs which can interfere with natural river processes including fish movements and migration. 

Tender documents for this project were published on the eTender website on the 20th of January 2023, with a consultant being awarded the project on the 25th of April 2023. Since this essential environmental surveys and reports have been initiated. 

Eight options have now been developed with this information which IFI are now seeking stakeholders feedback on to inform the process.

The new Barrier Mitigation Division was  established in April 2024 in IFI to specifically progress a barrier mitigation programme of works. The National Barrier Mitigation Programme will resource and enable dedicated staff to work on projects such as Annacotty.

This new division at IFI aims to improve river hydromorphology and connectivity in Irish catchments by strategically targeting barriers to fish passage and structures degrading river form, flow and function.  This will be done through a targeted programme on the implementation of mitigation. 

Government funding of €100 million for this programme has been made available to remove, mitigate and where possible lessen the ecological impact of river barriers on migrating and resident fish species.

Approximately 7,000 of the 73,000 potential barriers identified nationally will require removal or mitigation. Over the first phase of the programme (2014 -2017) a target of 257 barriers will be progressed. 

The EU Biodiversity Strategy 2030 aims to make 25,000 km of rivers free flowing by 2030. In line with this strategy Ireland’s fourth National Biodiversity Action Plan 2023–2030 has a target that requires the restoration of 300 km of rivers to a free-flowing state. 

The EU Nature Restoration Law is a new regulation by the European Commission to restore at least 20% of the EU’s land and sea areas by 2030 and repair all ecosystems in need of restoration by 2050.

The EU Water Framework Directive (2000/60/EC) requires all Member States to protect and improve water quality in all waters so that good ecological status is achieved by 2027. Ireland’s third River Bain Management Plan is called the Water Action Plan 2024. It specifically mentions Annacotty Weir as a pilot project in the programme for mitigation.

The EU Habitats Directive (92/43/EEC) conservation objectives for the Lower River Shannon SAC, aim to increase river accessibility for migratory species such as Atlantic salmon and lamprey.

The EU Eel Regulation (1100/2007) requires EU countries to implement recovery measures for European eel populations. The Annacotty fish passage project will help to achieve this goal. 

There are currently eight options available. These are: 

• Option A – Partial Removal of the Weir
• Option B – Complete Removal of the Weir
• Option C – Refurbishment of Existing Fish Ladder
• Option D – Lowering of the Existing Weir in conjunction with other fish passes
• Option E – Installation of Rock Ramp Fish Pass Downstream of the Weir
• Option F – Installation of Rock Ramp Fish Pass Upstream of the Weir
• Option G – Bypass Channel
• Option H – Retain Existing

In the first instances, all the options will be assessed by the consultants in terms of the environmental and engineering design implications. 

Depending on stakeholder feedback and the results of outstanding environmental and site investigation data, an option report will be compiled to document the process with a multi criteria decision matrix scoring elements of each option. A recommendation on the preferred option will then be made and its design will be progressed to develop the planning documentation. 

An online feedback form for the second public consultation is available to contribute to the process.

Stakeholder feedback is now open to inform the process and will be complete in Q1 2025. The project consultant will then collect the remaining environmental surveys, site investigation data and produce the options report to identify the emerging preferred option. A planning application submission will follow and subject to receipt of a granting of permission a tendering process for the construction contract will begin. The earliest window for construction to commence is in Q3 2026 that is subject to the instream window for construction works giving a final handover & commissioning phase of Q4 2026.

Dace is a cyprinid fish with a European-wide distribution but are not native to Ireland. It was first introduced to the Munster Blackwater in 1889 and were first reported below Annacotty Weir in the 1990s. An ESB survey recorded dace upstream of Annacotty Weir in 2001 and again at Barrington’s Bridge in 2010 and in 2013. Dace can already traverse Annacotty Weir. Any impact of weir alterations on the dace population will be assessed as part of the options report.

Almost the entire Mulkear catchment, including the River at Annacotty, is within the Lower River Shannon Special Area of Conservation (SAC). SACs protect important environments and species as listed in the EU Habitats Directive.

The Mill Building (RPS1614, NIAH Reg. No. 21900605) is a recorded protected structure and the associated Mill infrastructure is to be protected in all options An Architectural Conservation Impact Assessment Report will establish the impact in detail of the proposed option.

Refurbishing of the existing weir is one of the options under consideration. Refer to Option C – Refurbishment of Existing Fish Ladder for more details. 

Annacotty Weir is a significant priority barrier on the Mulkear River due to its location at the downstream end of the catchment, its height and full channel barrier blockage. It significantly impedes the migration of adult salmon and sea trout and completely blocks sea and river lamprey. Freshwater barriers can block or delay migrating fish, leading to increased mortality.

A detailed hydraulic model by the project consultant will be developed on the preferred option to assess the impacts to flood risk. See below photo of the Annacotty Weir at a time of flood with the weir drowned out. 

Limerick City and County Council as the Lead Authority, in partnership with the Office of Public Works (OPW) and their agents are advancing with the Limerick City & Environs Flood Relief Scheme that is examining the issue of flood defences for Annacotty.