Scientists propose alternative to WFD for river health assessment

A team of scientists led by the UK Centre for Ecology & Hydrology (UKCEH) has proposed an alternative standard to the Water Framework Directive (WFD) for monitoring river health.

The team criticised the WFD’s ‘one out, all out’ approach to criteria for waterbodies to achieve 'good' status, and said this measure masks improvements to freshwater biodiversity – including the richness of invertebrates, plants, fish and algae in rivers over recent decades.

They suggested a regular biodiversity audit could be introduced quickly to run alongside the WFD, to more clearly reveal the status of different species at any given location. This should be supported by statistical analysis of associated monitoring data on chemical concentrations, habitat quality, water temperature and flow to clearly identify what elements might be suppressing biodiversity.

Professor Andrew Johnson, who led the review, said: “There has been no increase in the number of waterbodies achieving good ecological status, which might appear to imply there have been no improvements for wildlife since full reporting for the Water Framework Directive began in 2009. This is not the case, and the disconnect between the scientific evidence and the ecological status results brings into question the value of the whole process.

“For example, the WFD would direct us to put a lot more money into further reducing phosphate concentrations, yet according to our statistical analysis, this may be less beneficial to overall biodiversity than tackling key metal contaminants.”

In time, the team envisaged that a combination of the proposed surface waterbody biodiversity audit, as well as chemical quality and human health standards, could replace the WFD classification.

The WFD was introduced by the EU and retained by the UK after Brexit. It requires governments to aim to achieve at least good ecological status for all surface water bodies by 2027, but it is highly likely that this target will be missed.

In the last classifications in 2019, just 16% of all water bodies assessed in England (including 14% of rivers) had good ecological status. In Wales, 40% achieved this standard in interim classifications in 2024.

If the proposed biodiversity audit were introduced, UKCEH said over 54% of rivers in England would achieve at least good ecological status.