Dramatic fall in river water quality

THERE has been a dramatic decline in Ireland’s high quality river water over the last 21 years, from 600 clean rivers to less than 60, a new report by the Environmental Protection Agency reveals.

The percentage of high ecological quality river sites almost halved between 1987 and 2008 – from almost 30% to less than 17%.

Suspected causes of the decline are nutrient inputs, siltation and acidification associated with activities such as forestry, agriculture and housing development.

The latest report on key indicators of the aquatic environment, Water Quality in Ireland 2007-2008, point out that rivers with the highest quality water are in less densely populated, less developed and less intensively farmed regions.

Manager of the EPA’s Aquatic Environment Programme, Dr Jim Bowman, said nutrient enrichment of surface and ground water remains at a high level with municipal and agricultural discharges being the key contributors.

“The dramatic decline in the number of high ecological quality river sites during the last 20 years, is largely due to low-level enrichment and siltation in upland areas. It is unacceptable and will have to be addressed,” he said.

Dr Bowman said the decline in the country’s really clean river waters had gone from around 600 in the late 1980s to less than 50.

“If a river gets polluted downstream, the recovery is derived from what is living in those areas upstream, which is really the font of life,” he said.

“Upstream is where salmon and trout go to spawn and if conditions are not right, their spawning season fails and that’s what our concern is about – we need to protect those rivers,” he said.

Dr Bowman said it was a “general malaise” that had spread throughout the country. But it was not too late to remedy the situation and one of the most important objectives of the Water Framework Directives was the protection of the country’s high status waters and the restoration of those that were degraded.

“It takes very little to degrade these. A small amount of nutrients, silt or acid can cause untold damage, whereas the same amount getting into the lower reaches of a larger river would hardly be noticed.”

Director of the EPA’s Office of Environmental Enforcement, Dara Lynott, pointed out that as well as applying protective measures to those sites assigned ‘high’ and ‘good’ status, almost 50% of river and lakes would require restorative measure, while 405 of estuaries and coastal areas would also need to be restored.

The EPA is also concerned about the deterioration of groundwater quality.

Dr Bowman said seven out of 10 monitoring stations had faecal coliforms present in at least one sample – an increase of 10% from the 2004-2006 monitoring period, indicating it had been contaminated by sewage.