Useful Data for Irish River Conservation / Water Quality

OCE-127779-J9Y4Q0

OEE AIE 2025 20

For the purposes of this AIE please ignore any records publicly available on LEAP Online

A total of 153 records were identified as relevant to your request

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Catchment Significant Pressures Description:

The significant pressures identified by the EPA during initial characterisation were Forestry, Domestic Waste Water Treatment Systems (DWWTPS) and Section 4 Discharge licences. The Unshin_050 has a High Status Objective, is a Blue Dot Catchment and forms part of the Unshin Special Area of Conservation (SAC). The biological Q score at the monitoring point dropped to Good in 2015, returned to High in 2018, dropped again to Good in 2019 and returned to High in 2020. This is a Protect referral to help reduce the impact of future forestry operations to water quality. Measures to reduce the impact from forestry are required.

Referral Significant Issue (s) Description

Phosphate is identified as the significant issue contributing to the decline in biological status of the Unshin_050. Sediment is also likely to be a contributing factor although the river has naturally occuring sediment (moderate – extensive) due to the nature of the bank margins, substrate and low elevation. Forestry activities are likely to further increase the levels of sediment load in the river.

Much of the forestry in the PAA was planted before 1990 i.e. before the introduction of Forest Service guidelines regarding buffer zone management along watercourses e.g. introduction of buffer zones, management of ground preparation and other forest operations to protect water quality, and therefore forestry poses a risk to water quality.
This referral is for minimising water quality impacts from future forestry operations in the Unshin_050. No deterioration is a requirement for High status Blue Dot sites. Therefore, protection measures will need to be put in place. A precautionary approach should be taken, and an effort should be made to minimise the risk from nutrients and sediment to the watercourse.
Example measures are proposed below.

Waterbody Name

Unshin_040

“Catchment Significant Pressures Description: The significant pressures identified by the EPA during Initial Characterisation were Forestry, Domestic Waste Water Treatment Systems (DWWTPS) and Agriculture. The Unshin_040 has a High Status Objective, is a Blue Dot Catchment and sections for the Unshin River Special Area of Conservation (SAC). The biological Q score at the monitoring point dropped to Good in 2015. A return to High status was noted in 2018 and 2019. This is a Protect referral to help maintain this improvement. Measures to reduce the impact from forestry are required.”

Referral Significant Issue (s) Description

Phosphate is identified as the significant issue contributing to the decline in biological status of the Unshin_040. Sediment is also likely to be a contributing factor although the river has naturally occuring sediment (moderate – extensive) due to the nature of the bank margins, substrate and low elevation. Forestry activities are likely to further increase the levels of sedimentand therefore nutrient load in the river.

Much of the forestry in the PAA was planted before 1990 i.e. before the introduction of Forest Service guidelines regarding buffer zone management along watercourses e.g. introduction of buffer zones, management of ground preparation and other forest operations to protect water quality, and therefore forestry poses a risk to water quality.

New felling was noted in the Unshin_040 in October 2020 (see photograph tabs). Overland pathways for sediment and nutrients were observed. Similar old forestry compartments are present in the Unshin_040 and represent a risk to future water quality.
For the reasons mentioned above, this is a Protect referral with the aim of minimising water quality impacts from future forestry operations in the Unshin_040. No deterioration is a requirement for High status Blue Dot sites. Therefore, protection measures will need to be put in place. A precautionary approach should be taken, and an effort should be made to minimise the risk from nutrients and sediment to the watercourse.

Example measures are proposed below

Catchment Significant Pressures and Issues Description:

The significant issues identified for the Lingaun_010 were phosphate and sediment with forestry identified as a significant pressure for the third cycle. This waterbody deteriorated to moderate status in 2013-2018. EPA biological assessment at the monitoring point in 2020 recorded a Q Value of 3-4* (* siltation impact). As the waterbody has a high status objective, it is very sensitive to low levels of inputs, and therefore all risks to water quality will be referred where identified. This restore referral is being issued to highlight issues around felling and measures that are needed to minimise risk of sediment loss to the river.

“Description of Referral Area: The referral area relates to the section of the Lingaun_010 immediately upstream of referral point, 16L010050_1150 (See Map 1). Eleven hectares of privately owned forestry adjacent to the waterbody for approximately 600 metres was clear felled in 2023. This was the only area of recently felled forestry identified during local catchment assessment in the waterbody.”

Referral Significant Issue (s) Description

SSIS was undertaken at EPA operational station: Br u/s Whitehall Br (RS16L010050; 16L010050_0100 point on Map 1) in July 2023. The site was found to be Probably not Significantly Impacted with a score of 8. However, tolerant taxa were present in excessive numbers and the site was not considered to be meeting high status requirements. Moderate to high levels of interstitial sediment were also noted. Chemistry sampling in August 2023 and January 2024 did not show any exceedances of the EQS thresholds.

A catchment walk was undertaken in August 2023 in the clearfelled area 2 km upstream from Br u/s Whitehall Br. It was found that buffers had been maintained in some areas but absent in other areas with clearfelling occurring right up to the river bank. In-drain sediment screens were in use in the clearfelled area but some were operating more effectively than others. Some were found to have disintegrated while others were likely to be bypassed in high flow situations. One sediment screen had been erected in a tributary of the waterbody.

Recommendation: This waterbody has a high status objective but is currently at moderate status. Collapsed and not functioning siltraps (found in the area above 16L010050_1150) can potentially release stored fine sediment to the river during rainfall events. Note that sediment issues were found at the EPA monitoring location downstream during LAWPRO local catchment assessment and EPA Q-value assessment. It would be recommended to ensure the adequate functioning of the siltraps in the referral area and ensure their maintenance after clearfelling activities.

Catchment Significant Pressures and Issues Description: The significant issues identified for the Lingaun_010 were phosphate and sediment with forestry identified as a significant pressure for the third cycle.

This waterbody deteriorated to moderate status in 2013-2018. EPA biological assessment at the monitoring point in 2020 recorded a Q Value of 3-4* (* siltation impact). As the waterbody has a high status objective, it is very sensitive to low levels of inputs, and therefore all risks to water quality will be referred where identified.

This protect referral is being issued to highlight issues around felling that may be needed in future to minimise risk of sediment loss to the river.

Referral Significant Issue (s) Description
SSIS was undertaken at EPA operational station: Br u/s Whitehall Br (RS16L010050) in July 2023. The site was found to be Probably not Significantly Impacted with a score of 8. However, tolerant taxa were present in excessive numbers and the site was not considered to be meeting high status requirements. Moderate to high levels of interstitial sediment were also noted. Chemistry sampling in August 2023 and January 2024 did not show any exceedances of the EQS thresholds.
A catchment walk was undertaken in August 2023 in the clearfelled area 2 km upstream from Br u/s Whitehall Br. It was found that buffers had been maintained in some areas but absent in other areas with clearfelling occurring right up to the river bank. In-drain sediment screens were in use in the clearfelled area but some were operating more effectively than others. Some were found to have disintegrated while others were likely to be bypassed in high flow situations. One sediment screen had been erected in a tributary of the waterbody.

While LCA undertaken within this waterbody demonstrates impact and biology not considered to meet certain high status criteria, it is important to mention that this forestry protect referral relates to observations on the ground showing enhanced risk from the failure of sediment screens in forestry drains and clear felling on the river bank.

Recommendation: protection measures will be required around future clearfelling to ensure that silt trapping measures are effective (ensure proper maintenance during and after clearfelling activities). There is also a need to establish proper setbacks (restructuring of the forest) for future planting activities. It is important to highlight the high status objective and therefore high sensitivity of this waterbody within future clearfelling applications.

Forestry (Owner) Coillte

“Catchment Significant Pressures Description: The significant pressures identified by the EPA at the initial characterisation stage were forestry and hydromorphology (river bank erosion). Biological status at the WFD operational monitoring station Br NW of Caunteens had been at high (Q4-5) from 2006 to 2020 but dropped to good (Q4) in 2021. The current hydromorphological condition (RHAT) is only at good in this Blue Dot waterbody. The hydromorphology pressure is being dealt with by ASSAP.”

Referral Significant Issue(s) Description

Sediment was the only issue identified during LCA at Site 1 which is also the EPA monitoring station for Isknagahiny Lough Stream_010 (Maps 1 & 2). More sediment than expected was observed there in September 2020. However, SSIS indicated that the invertebrates communities were not significantly impacted in June 2021 despite the noticeable interstitial sediment. Additional similar habitats assessed further upstream showed similar invertebrate communities. High biological status (Q4-5) was assigned to this site in 2020 however subsequent to LAWPRO’s assessment, the EPA biologists returned a Q4 for this site in 2021.

This forest referral area is within a priority Fresh Water Peral Mussel area. Contiguous to the forested area, the landscape is made up of moors and heathland. The slope within the forestry is on average >40%, therefore stream power would be expected to be very high. This coupled with high rainfall events and rapid run-off have substantial peat and sub-soil erosion potential.

The ongoing risk of impact from sediment mobilisation and future forest management operations is ever present in this catchment. Where necessary, mitigation measures need to be put in place in advance of future forest operations and appropriate management of windblown trees should be implemented to eliminate the risk of sediment loss to the sensitive aquatic environment in this waterbody and others downstream.

Mitigation measures are outside the remit of LAWPRO however, some general proposed measures are outlined below.

Catchment Significant Pressures Description: The Glaskeelan_010 waterbody has a High Status Objective and is a Blue Dot site. It sits within the Leannan Priority Area for Action for LAWPRO and is one of Irelands Top 8 Freshwater Pearl Mussel Catchments. Forestry was the suspected Significant Pressure identified during Initial Characterisation causing hydrological, morphological and nutrient issues.

Referral point Upstream EPA Monitoring Point ‘Br W of Roshin’.
Forestry (Owner) Coillte

“Referral Significant Issue (s) Description : Existing forestry between Glenveagh National Park and Br W of Roshin is likely to be a pressure based on observations seen during the 2021 surveys. Existing hydromorphological pressures from forestry were observed such as the planting of conifers right up to the bank edge. In several cases, the riverbank was slumping, and sods of earth material were falling into the channel, introducing a source of sediment to the river. Overdeepening of the channel was common, especially in the forested area. Excessive growth of broad leaved macrophytes (Potamogeton sp and Nuphar lutea) were noted where overdeepening has led to a change in flow dynamics from a fast upland river to a sluggish channel. Old forestry drainage channels have direct connectivity to the watercourse, providing a preferential flow pathway for nutrients and sediment. Trash lines were noted in the forestry, and forestry debris such as pine needles will be introduced into the river as floodwater recedes. Measures to reduce the impact of forestry are required for the Glaskeelan. Such measures must be done sensitively (given the importance of the catchment for the protected freshwater pearl mussel and salmonids) and in collaboration with stakeholders. Possible mitigation measures are to be determined by the Forestry Service but could include sensitive removal and or thinning of the conifer plantation, rewetting of the Blanket Peat habitat in which the coniferous forestry stands and allowing natural regeneration of native trees on mineral soils. A Catchment Based Approach to River Restoration to restore the functionality of the watercourse due to historical morphological alterations (overdeepening) is recommended. ‘Anthropogenic – Unknown’ has been suggested as another Significant Pressure affecting the Glaskeelan_010. On 28th July 2021, EPA reported a Red Dot notification for the monitoring point ‘Bridge W of Roshin’ (Lough Gartan). The macroinvertebrate Q dropped three classifications from High to Poor. From 18th to 26th July 2021 – two days before the EPA kick sample, there was a heatwave and western spate rivers such as the Glaskeelan were subjected to nine days of average air temperatures of over 22°C. Several nearby waterbodies (e.g Glentornan, Gweebarra_010, Gweedore_010) surveyed in or just after the heatwave also saw a decline in Q score.

Hydromorphological issues can make temperature stress more intense and pressures such as overdeepening were observed within the forested area of Glaskeelan. It is suspected that the high temperatures along with the hydromorphological issues on the Glaskeelan led to a severe drop in macro-invertebrates leading to the Red Dot notification.”