IFI submission relating to a restoration plan for a section of cut-over bog that has the Esker River flowing through it.
Photos highlight extent of hydro-morphological issues.
IFI hope to carry out restoration measures along much of the Esker River, as there is excellent habitat potential.
Site visits by IFI have highlighted significant modifications to watercourses flowing through, adjacent to and downstream of the proposed restoration sites.
The modifications noted included:
- Culverting/piping of waters
- Construction of on-line silt ponds
- Realignment/straightening of watercourses is problematic for a number of reasons including the fact that it results in a net loss of habitat. Realignment of channels often results in a highly degraded hydro-morphology with the loss of natural sinuosity and natural instream variation characterized by the pool/glide/riffle sequence. Realignment may also negatively impact upon gravel recruitment at the realigned site and in waters downstream.
- The widening of watercourses, (regularly associated with realignment and deepening) often results in a highly degraded hydro-morphology with the loss of natural sinuosity and natural instream variation characterized by the pool/glide/riffle sequence. In shallow waters a braided channel with limited depth for fish to reside is often the result, while in deeper waters an over-abundance of aquatic plants clogging the channel is regularly encountered.
- Culverting is potentially damaging to fisheries waters as it may (1) block/impede the free passage of fish, (2) result in a loss of fisheries habitat and (3) hinder the detection of pollution, while (4) poorly designed/under-sized culverts may be prone to blockages with potential for bank erosion and/or flooding.
- The construction of on-line silt ponds on fisheries waters results in the loss of fisheries habitat over long stretches of channel and may impede the free passage of fish.
Specific issues noted by IFI during site visits included:
- The Doden River which bisects the Esker bog, represents excellent salmonid habitat, however long sections of this important watercourse have been straightened and deepened, while a very large on-line silt pond was created on this watercourse. An electro-fishing survey of this river in May 2021 highlighted populations of brown trout in this watercourse. IFI request that the restoration of the fisheries habitat of this watercourse be included as part of this plan.
- A tributary of the Esker River forms the western boundary of the Esker Bog and IFI inspections highlighted that this watercourse represents fisheries habitat. The inspections also highlighted issues including, fish passage related to perched culverts, deepening and widening and the passage of this stream through a large silt pond. An electro-fishing survey of this river in May 2021 highlighted populations of brown trout and lamprey in this watercourse.
- Sections of the main Esker River forming the southern boundary of the Esker bog were found to have been deepened significantly. IFI hopes to explore the potential for habitat restoration along these sections of channel and we ask that such works could be included as part of this bog restoration plan.
- With regard to the Cavemount site, IFI have identified excellent salmon habitat potential a short distance upstream of here. IFI hopes to explore the potential for habitat restoration along this section of channel. Our inspection of the Bord na Mona property highlighted a significant constriction in the form of a culverted section of Esker channel, which was noted to be partially blocked. IFI request that this plan would include the removal of this culvert and if a crossing is required that the present structure be replaced with an alternative that is not prone to blockages, will not act as a constriction during high flows and does not result in any loss of fisheries habitat.
- IFI request that all watercourse crossings be assessed from the point of view of constrictions on flow, loss of fisheries habitat and barriers to the free passage of fish.
IFI request that habitat restoration of the Esker River flowing through the Cavemount site be undertaken as part of this bog restoration plan.
Sections of this channel were straightened in the recent past and we request that the potential for this section of channel to develop some sinuosity and in-stream variation be included. It is likely that restoration of this section of channel will require the re-introduction of some gravels also.
With regard to the proposed rehabilitation plans, IFI have a number of concerns, including:
- The plans state that the silt ponds will continue to be maintained during the rehabilitation and decommissioning phases. IFI request that all maintenance/use of on-line silt ponds cease and that habitat restoration of these important watercourses be made an integral component of the bog restoration proposals.
- We note that water quality monitoring will be established, with a suite of physico-chemical parameters referred to. IFI believe that biological monitoring of watercourses should be central to any water quality monitoring program.
- Our knowledge of this area is that the invasive fish species Dace is present in the Esker River, yet it is not referred to in the section detailing invasive species.
- Fishery assessments of the Esker and its tributaries have highlighted populations of brook lamprey an annex II species in the Habitats Directive. The potential for the re-establishment of populations of salmon here should also be included in the section “Species of Conservation Interest”.
- IFI request that the re-establishment of populations of native fish species such as salmon, brown trout, European eel and lampreys be included as an important component and target of Ecosystem services linked to these bog restorations.
IFI is keen to build on recent water quality improvements in the Black River, which drains 21% of the Barrow River catchment and to restore and increase populations of salmon and other native fish species over large sections of this system. Existing populations of salmon within the Black River are already an integral component of the Barrow River SAC populations of these species and as these populations expand in numbers and range their importance will increase significantly.
IFI believe that the implementation of restoration plan/plans, throughout the Esker/Daingean/Black River catchment to address the water quality & hydro-morphological issues referred to above, will be an important part of the restoration of populations of salmon & other species for which the Barrow River was SAC designated.
In addition the implementation of such plans will also be central to Ireland’s requirements for the implementation of the requirements of the Water Framework Directive.
IFI welcome the Bord na Mona, Biodiversity Action Plan 2016-2021 statement that “the main aim of rehabilitation will be to re-wet former production areas as much as possible to maximize the benefits for biodiversity and carbon”.
IFI believe that the benefits for biodiversity referred to above can be increased significantly with the inclusion of river habitat restoration in these plans and we request that applicant expand these bog restoration plans to include a commitment to river habitat restoration throughout the Daingean/Esker and Figile systems.
[Bord na Mona responses to follow]
Cutaway Bog Decommissioning and Rehabilitation Plans
Bord na Mona’s Cavemount Bog in County Offaly is located circa 4 km north-east of Daingean and circa 12 km east of Edenderry.
Esker Bog – Bord na Mona’s Esker Bog in County Offaly is located circa 9 km south-west of Edenderry