Smaller first and second order streams comprise over half the length of river channel in most catchments in Ireland.

The Western River Basin District has developed a new scoring system for small streams which is designed to confirm the risk status of smaller streams.It has been shown to be highly correlated with a range of internationally used European biotic indexes and it also has significant correlations with water quality parameters such as phosphate and nitrate.

The Small Stream Scoring system is a rapid field-based system based on macroinvertebrates. The use of macroinvertebrates gives a reliable assessment which integrates pollution events over some considerable time previously – as opposed to grab sampling chemistry which gives instantaneous assessments of water quality.

An initial training course in macroinvertebrate taxonomy is required plus ongoing validation of taxonomic accuracy of the operators is also required. The level of taxonomy required to confirm that a stream site is in the ‘at risk’ category and is suffering from an upstream pollution source is not as onerous, however, as that required to assign a full Q-Value.

This project provided detailed geographical information concerning risks of pollution in all the small streams within the Moy catchment. 1200 sites were surveyed in the catchment giving a complete overview of pollution sources at high resolution. The project had a number of proposed components:

Small Stream Survey to prioritise those sub-catchments where pollution problems are most evident

Follow-up surveys in the at-risk sub-catchments – stream walking to identify pollution sources where they enter the streams where possible. Photography with GPS locations of pollution points.

Liaison with Local authority, fisheries boards regarding follow-on farm surveys and implementation of the appropriate existing water pollution and fisheries legislation with view to the issuing of, for example, warning notices and Section 12 Notices under the Water Pollution Act by the appropriate authorities

GIS Mapping of results indicating the main sources of pollution risk in the catchment

Liaison with and provision of real-risk data for MarCon Decision Support System for deciding on location and type of optimal measures as part of the Cycleau Moy Valley project – explore options such as e.g. the Penn State AVGWLF Watershed Model developed by Prof Barry Evans or Mikebasin from Danish Hydraulic Institute.

Organising the survey results in an easily accessible database – perhaps with an online public access showing the areas at risk and not at risk.