Just one of Northern Ireland’s 21 lakes has been classified as ‘good’, according to a report released this week by the Department of Agriculture, Environment and Rural Affairs (DAERA).
It compares to 2015 and 2018 versions of the same study where five lakes ranked as ‘good’.
Worryingly for farmers, environmental officials have linked the problem to increasing phosphorus levels in the water.
The latest NI Water Framework Directive Lake Quality update offers summary information on the status of lakes for the three River Basin Districts in Northern Ireland based on data collected up to the end of 2019.
The study covers all bodies of lake water in Northern Ireland with an area greater than 50ha.
Methodology
The Water Framework Directive requires the Northern Ireland Environment Agency (NIEA) to classify water bodies’ status, protect that status from deterioration and, where necessary and practicable, to restore water bodies to good status.
When assessing water quality, NIEA said it considers both the ecological and chemical quality, as well as the pressures that can affect them.
The ecological and chemical classification results for surface waters are combined to give an overall status in one of five classes: bad; poor; moderate; good; and high.
The overall status of a water body is determined by the lower of its ‘ecological status’ and its ‘chemical status’ – the “one out, all out rule” means that if either is deemed poor then the water quality must be rated accordingly.
Classification of all surface water bodies and groundwater bodies will be updated in 2021.
Why has lake quality dropped so much?
A DAERA spokesman told AgriLand the main reason for the deterioration in these lakes is increasing levels of the plant nutrient phosphorus and associated ecological changes.
This is not unexpected, as increasing levels of phosphorus led to 22% of rivers dropping at least one class in the 2018 classification.
“Lakes take longer to respond to environmental changes, due to the large bodies of water providing greater capacity to dilute pollutants.
“However, over several years, nutrients will accumulate in water and sediments and lead to deterioration in status,” he said.
What next?
The department spokesman explained that work was currently underway to prepare the third cycle of the region’s River Basin Management Plan, set to be published next year.
“DAERA takes the issue of water quality very seriously, and already has a number of measures in place to tackle the issue,” he said.
“This includes Tranche 4 of the Environmental Farming Scheme (EFS), which includes measures to protect watercourses, and the Water Quality Improvement strand of the Environmental Challenge Fund Competition.
It is encouraging to see so many farmers participating in EFS to help protect and enhance the natural environment. Tranche 4 of Wider Level opened on August 17 and will close on September 11.
Applications for the Water Quality Improvement grants opened on August 3 and closed on August 31, 2020.
The department has also been working alongside NI Water and the Department for Infrastructure (DFI) regarding the delivery of the water capital investment programme.
“This is complemented by working closely with NI Water in the regulation of its activities in managing and treating waste-water, to ensure high standards of environmental protection and compliance,” the spokesman added.
