Classification

We produce an annual classification for all the water bodies in Scotland.

Most of our water environment is already in a good condition and subject to fewer pressures than most other European waters.

However, there are a number of significant environmental problems caused by a number of pressures, including diffuse and point source pollution, alterations to beds, banks and shores, alterations to water levels and flows and the presence of invasive non-native species.

In order to measure these pressures and their potential effects, we use an aquatic classification system which covers rivers, lochs, estuaries, coastal and groundwater bodies. These are split into management units called water bodies, with a classification produced for each body (the number of water bodies between years varies slightly, as some water body boundaries are reviewed to ensure that they can be managed appropriately).

Surface water bodies are classified using a system of five quality classes – high, good, moderate, poor and bad, with groundwater classified as good or poor. In general, the classification of water bodies describes by how much their condition or status differs from near natural conditions. Water bodies in a near natural condition are at high status, while those whose quality has been severely damaged are at bad status.

Our system was devised following EU and UK guidance and is underpinned by a range of biological quality elements, supported by measurements of chemistry, hydrology (changes to water levels and water flows) morphology (changes to the beds, banks and shores of water bodies) and assessment of invasive non-native species.

The classification is produced using samples from a range of years, ending in December of the classification year. These samples are analysed, the data checked, and the classification results calculated, checked and published, normally by July of the following year.

Once we have collected and collated our results, we can set objectives for improving the water environment.

Our river basin management planning pages contain more information on the classification system and how it is used. The Scottish Government’s formal Directions on the classification of water bodies give more detail on how the system is implemented:

These Directions apply for classifications produced from years 2013 on. Prior to the 2013 classification, the 2009 Directions were in force, and results were calculated according to those rules.

For more information about our classification systems, please contact us.