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NSF Characterisation

WFD Characterisation
Dr Tom Leatherland, Manager of EQRAD, SEPA

General introduction

Article 5 of the EC Water Framework Directive requires the characterisation of all waters within each river basin district and the production of a report on the results of this process. Scotland will therefore have to produce a report for the bulk of Scottish waters in the Scotland RBD, and work with the Environment Agency to report on the cross-border RBD covering the Tweed and Solway catchments. SEPA plans to consult on a draft report covering the characterisation of all Scottish waters in late summer 2004.

Water bodies at risk

For WFD purposes, all waters (fresh, ground, coastal and transitional) are divided into identified units called "water bodies". Water bodies are the units which will be described, monitored and managed to ensure that objectives of the WFD are attained. Characterisation is the process of identifying the type, and all significant pressures on every individual water body, and assessing the impact of these pressures on the ecological, chemical, and hydrological quality of each water body. Where the pressures are found to be such that the water body is clearly not of good status as defined by the directive, or such that it may not be of this quality in 2015 unless action is taken, then it is deemed to be "at risk". The report must also include an economic analysis of water use

A later phase of WFD, river basin management planning, will tackle and report on the management measures which will be put in place to ensure that all water bodies meet their quality objectives by 2015. Characterisation is not a once and for all activity, but must be reviewed by late 2013, and every 6 years thereafter.

The WFD default quality objective, "good status", is defined as no more than slight departure from undisturbed natural conditions. It is seen as important that good status is equivalently interpreted by all member states, and with this objective an intercalibration exercise for some biological elements is underway, and is due to be completed in 2006. Until this is completed, Member States must make assumptions about the probable level of good status, in order that water bodies "at risk" of not attaining it can be identified for characterisation purposes.

The characterisation process is well underway in Scotland . Scottish waters have been provisionally divided into ~3400 water bodies, of which 350 are lakes, and 2360 are riverine. Presently, over 50% of these have been provisionally identified as "at risk", with this incidence lowest for coastal waters, and highest for lakes.

SEPA current classification schemes identifies under 20% of the water environment as polluted. These schemes focus predominantly on the effects of organic enrichment and toxic substances. The pressure types under consideration for the WFD are:

  • Point source discharges
  • Pollution from diffuse sources
  • Abstraction
  • Flow regulation and river continuity
  • Morphological alterations (such as "canalisation")
  • Artificial recharge (groundwater only)

Consideration of additional new pressures is inevitably leading to the finding that a much higher proportion of Scottish waters are not of "good" status, in comparison with current classifications. Thus of the lakes so far assessed, 23% are classed as at risk of point and diffuse source pollution, but 34% are subject to morphological change and 65% to abstraction or flow regulation significant pressures. The WFD also requires consideration of possible impacts on a wider range of biological elements than are currently routinely monitored, ie, including fish, phytobenthos and macrophytes. This also has the effect of increasing the proportion of waters found to be "at risk".

Over the next five years, it is expected that further investigations into impacts upon the water environment will lead to a reduction in the total numbers considered to be at risk. The current view is that by 2009, the proportion of the water environment which will risk failing the Directive's objectives may be of the order of 30%.

The characterisation report is also required to list all "protected areas" within the RBD. These are defined by the directive as comprising all areas "designated as requiring special protection under specific Community legislation for the protection of their surface water or groundwater or for the conservation of habitats and species directly depending upon water". This includes bathing waters, Natura 2000 sites and drinking water sources.

Information regarding pressures on groundwaters, affecting both quality and quantity, is currently being gathered.  

Suggested issues for discussion

1. SEPA is identifying three levels of certainty in identifying a water body at risk: low, medium and high confidence. SEPA is identifying three levels of certainty in identifying a water body at risk: low, medium and high confidence. SEPA will only identify a water body as being at risk if it is at medium or high confidence. Low confidence sites will be left until the next round of characterisation (in six years time). Is this an acceptable approach?

2. Currently SEPA is using the best available information to assess whether a water body is "at risk". This could use numeric data or it could be based upon expert judgement? Currently SEPA is using the best available information to assess whether a water body is "at risk". This could use numeric data or it could be based upon expert judgement? What level of proof should SEPA require to identify a water body as being at risk?  

3. Over the next two years there will be negotiations at the UK and EU level which will confirm the meaning of good status. Over the next two years there will be negotiations at the UK and EU level which will confirm the meaning of good status. At the moment the Environment Agency, SEPA and the Environment & Heritage Service of Northern Ireland are suggesting that the current definition of good in their classification schemes is an appropriate target for the next 20+ years. How ambitious should Scotland be in its input to the development of the EU interpretation of good status?

Page updated: Friday, June 24, 2005