This report provides an update on the quality of water in Ireland’s rivers, lakes, transitional and coastal waters and groundwater using information collected in 2022.
The EPA undertakes a full assessment of the overall quality and ecological status of Ireland’s waters every three years and we report on the indicators of water quality in the intervening years to provide an update on trends in the biological quality and nutrient levels of our waterbodies. This indicators report provides an update on the water quality of Ireland’s rivers, lakes, estuaries, coastal, and groundwaters using monitoring data collected in the 2022 period.
The number of river water bodies in bad condition has reduced to two; Annagh (Clare)_010 in Co. Clare (the cause of this recent deterioration is currently under investigation) and Laune_010 in Co. Kerry (where urban waste water is a pressure).
The five lakes with highest total phosphorus concentrations over the 2020-2022 period are:
– Naglack (Co. Monaghan) – 3 year average 0.33 mg/l P
– Inner (Co. Monaghan) – 3 year average 0.21 mg/l P
– Farnham (Co. Cavan) – 3 year average 0.21 mg/l P
– Egish (Co. Monaghan) – 3 year average 0.16 mg/l P
– White Rockcorry (Co. Monaghan) – 3 year average 0.10 mg/l P
Twenty one of the 103 (20%) estuarine and coastal water bodies assessed were in unsatisfactory condition for DIN.
The majority of the estuaries with the highest concentrations above the assessment thresholds for winter dissolved inorganic nitrogen were in the south and south east of the country, which is also the area with the highest river nitrate concentrations.
Four of the top five highest areas were in the south east (with the exception of the Castletown Estuary), namely:
– Glashaboy Estuary (Co. Cork) – 124% above threshold value
– Wexford Harbour (Co. Wexford) – 89% above threshold value
– Castletown Estuary (Co. Louth) – 85% above threshold value
– Upper Barrow Estuary (Co. Kilkenny) – 83% above threshold value
– Corock Estuary (Co. Wexford) – 83% above threshold value
An analysis of change over time has shown that nitrogen levels have significantly increased in four water bodies from 2012 to 2022:
– Lee Estuary (Co. Cork)
– Wexford Harbour (Co. Wexford)
– Swilly Estuary (Co. Donegal)
– Mulroy Bay (Co. Donegal)
Significant nitrogen decreases have been observed in the following water bodies since 2012:
– Erriff Estuary (Co. Galway)
– Broad Lough (Co. Wicklow)
– Dublin Bay (Co. Dublin)
– Malahide Bay (Co. Dublin
Nearly all (97%) estuaries and coastal waters assessed were in satisfactory condition for phosphate.
Only three waterbodies were in unsatisfactory condition, having exceeded the relevant threshold:
– Deel Estuary (Co. Limerick) – 55% above threshold value
– Maigue Estuary (Co. Limerick) – 40% above threshold value
– Castletown Estuary (Co. Louth) – 6% above threshold value
An analysis of change over time from 2012-2022 shows that there has been significant increase in winter median phosphate concentrations in 10 water bodies:
– Cork Harbour (Co. Cork)
– New Ross Port (Co. Wexford)
– Barrow Nore Estuary Upper (Co. Wexford)
– Outer Cork Harbour (Co. Cork)
– Upper Barrow Estuary (Co. Kilkenny)
– Boyne Estuary (Co. Louth)
– Roaring Water Bay (Co. Cork)
– Nore Estuary (Co. Kilkenny)
– Killary Harbour (Co. Galway)
– Avoca Estuary (Co. Wicklow)
Two water bodies showed a significant decrease, the Lower Lee estuary (Co. Cork) and Killybegs Harbour (Co. Donegal)