The potential benefits of catchment management for improving drinking water quality are widely recognised and evidence is beginning to show that this is a cost-effective way to reduce the costs of treatment. There are also benefits beyond the protection and improvement of drinking water quality including benefits for biodiversity, climate change and flood management as well as wider environmental parameters such as those relating to good ecological status required under the Water Framework Directive.
In order for there to be a method for the economic regulation of catchment management, the costs and benefits of catchment management in comparison with traditional treatment solutions need to be identified. Although catchment management projects may improve water quality, this does not always translate into lower treatment costs. It is, therefore, important to be able to separate improvements in water quality that reduce treatment costs from those that do not and from those that benefit the wider environment.
In Scotland, although drinking water is predominantly of excellent quality there is a need to use catchment management to protect drinking water and help make quality resilient to changes e.g. in land use or climate as well as driving down the costs of treatment. The main pressures are from colour in upland peaty catchments, faecal contamination, pesticides and nutrients. Scottish Water and SEPA are working together via the Sustainable Land Management Scheme and the Rural Diffuse Pollution Plan, respectively.
- A review of the methods used by those (e.g. water companies, catchment groups) using catchment management to improve the quality of drinking water to evaluate if their approach leads to a reduction in treatment costs and wider benefits. This work should include a review of the indicators of success (i.e. a reduction in treatment costs and wider benefits) that have been used to evaluate the different methods and identify and any gaps in indicators. Recommendations on which are suitable for Scotland should be made.
- A short and simple description of potential catchment management measures to improve drinking water quality.
- Model the effects of the measures implemented in catchment management plans
- Determine the most cost-effective way to meet drinking water quality standards?
- Develop a method (i.e. conceptualisation of the previous phases) to allow for the economic regulation of catchment management and pilot it in the three catchments in Scotland modelled