Derry-Coolboy-Rosnastraw Priority Area for Action Desktop Report


Derry-Coolboy-Rosnastraw Area for Action (PAA) consists of eleven waterbodies: Derry_010, Derry_020, Rosnastraw_010, Rosnastraw_020, Coolboy_010, Coolboy_020, Shillelagh_010, Derry_030, Derry_040, Derry_050 and Derry_060.

It is located mainly in Wicklow County and the area forms catchment of the River Derry (with its tributaries Rosnastraw stream and Coolboy River), which is an important tributary of the River Slaney.

At the time of PAA selection all waterbodies of this PAA were At Risk of achieving their WFD environmental objectives.

Since then, the 2013-2018 ecological status improved in four waterbodies (Coolboy_010, Coolboy_020 (high status objective), Derry_050 and Derry_060), and 2019 biological surveys indicate further improvements in water quality in Derry_020, Rosnastraw_010, Derry_030 and Derry_040.

The main focus of LAWPRO work will be therefore on the waterbodies that require additional work to improve water quality (Derry_010, Rosnastraw_020 and Shillelagh_010 (which declined to moderate conditions in 2019)), but also Derry_040, where moderate ecological status is driven not only by the failing invertebrate status but also moderate fish status.

The risk of failing ecological status in future WFD cycle in other waterbodies will be also considered.

Review of the physico-chemical data from the Environmental Protection Agency (EPA) and also the investigative sampling carried out by Wicklow County Council indicates that ammonium is a significant issue in Derry_010, while the significant issues in Rosnastraw_020 and Shillelagh_010 are unknown.

Short diffuse pathway in the poorly drained soil setting may exist in Derry_010 as well as a point source that may contribute to the ammonium inputs in Derry_010. Furthermore, despite improvements in water quality there is an increasing trend in Total Oxidised Nitrogen further downstream in the PAA (Derry_030, Derry_040 and Derry_060), where free draining soils dominate, and subsoils are very thin (with extreme and x-extreme groundwater vulnerability) providing risk of nitrate leaching to groundwater and further risk of failing future ecological status assessments.

The main pressures identified in Derry_010, Rosnastraw_020 and Shillelagh_010 is agriculture with potential farmyard management issues noted during initial characterisation process.

Forestry is another potential pressure in Derry_010, however, it was not confirmed to be significant in the desk study.

Additional pressures within the PAA include urban waste water with four wastewater treatment plants (WWTPs) located across the PAA and industry (one facility).

Local Catchment Assessment (LCA) is planned to confirm whether WWTPs and industry remain to be pressures within the PAA.

More focused LCA is planned in Derry_010, Rosnastraw_020 and Shillellagh_010 to narrow down the area of impact. This will include biological surveys (Small Stream Impact Score, SSIS) and chemistry sampling. Inland Fisheries Ireland will be involved in the process to confirm drivers of moderate fish status in Derry_040.

Additional work is planned to confirm good biological conditions (or high in Coolboy_020) at the remaining waterbodies.

The Derry-Coolboy-Rosnastraw PAA was selected as a priority area for action in the 2nd cycle.

The EPA report includes the following reasons:
• The most important tributaries on the Slaney for salmon spawning.
• Building on planned in stream works by Inland Fisheries Ireland on Coolboy_010 at Coolattin Estate. Three potential ‘quick wins ‘.
• Eight deteriorated water bodies.
• One At R is k High Ecological S tatus objective water body.
• Derry_010 is failing its protected area objectives for drinking water (pesticides).

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