Environmental watchdog highlights 'alarming' deterioration in water quality in rivers

Cork Harbour has lost its good water quality status. File picture: Larry Cummins

The water quality in nearly half of Ireland's rivers, lakes, and waterways is in "unsatisfactory" condition, with farming run-off in the south the culprit for much of the "alarming" deterioration.

That is according to the Environmental Protection Agency (EPA), which warned the further decline in water quality means Ireland is currently off course to meet the EU and national goal of restoring all waters to good or better status in the next five years.

"Only just over half of rivers, lakes, estuaries and coastal waters are in satisfactory condition. The overall ecological health of these surface waters has declined across all water body types since the last assessment from 2013-2018," the EPA said in its Water Quality in Ireland report for 2016 to 2021.

This means these water bodies are less able to support healthy ecosystems for fish, insects and plants, it said.

Coastal waters had the highest percentage of waters in high or good ecological status (81%) followed by lakes (69%), rivers (50%) and transitional waters (36%), which have the worst water quality, the EPA scientists found.

There has been a 1% decline in the number of river water bodies in satisfactory condition since the last report. 

We are failing to protect our highest quality rivers; only 43% of our rivers which should be at high status are achieving that standard. Over the period of this assessment, there were 161 fish kills recorded. Any fish kill is unacceptable and their causes need to be eradicated," 

the EPA report said.

There has been a 2.7% decline in the number of lake water bodies in satisfactory condition, a marked decline of 15.7% decline in the number of estuary water bodies in satisfactory condition, and a 9.5% decline in the number of coastal water bodies in satisfactory condition.

The quality of freshwater and marine ecosystems is being damaged mainly by run-off of nutrients, sediment and pesticides from agricultural lands and farmyards, and activities such as land drainage, navigational dredging and the presence of barriers such as dams, weirs or culverts in water courses.

Poorly treated sewage

Discharges of poorly treated sewage from urban wastewater treatment plants, domestic treatment systems and stormwater overflows is also an issue, along with run-off of nutrients and sediment from forestry operations.

Some 43% of river sites, mostly in the south and southeast of the country, have high nitrate concentrations, while nearly a third of river sites (30%) and a third of lakes (33%) have elevated phosphorus concentrations. Phosphorus levels are particularly high in lakes in the North-East of the country, the report found.

Director of the EPA’s Office of Evidence and Assessment Dr Eimear Cotter said the scale of the declines in estuaries and coastal waters is "alarming"

"In recent years, the EPA highlighted that nutrient levels in our rivers and groundwaters are too high and that trends were going in the wrong direction. We are now seeing the impact of these emissions on our estuaries and coastal waters. 

"Areas such as Cork Harbour, Wexford Harbour and the Slaney, Suir and Nore estuaries have lost their good water quality status. This directly impacts the marine biodiversity and ecological value in these areas," she said.