Solway Tweed river basin characterisation

Analysis of Impacts and Pressures has been undertaken separately in England and Scotland, (although both follow a common UK TAG approach) and hence different information on pressures and impacts is available for the Solway Tweed in relation to the Scottish and the English areas. Similarly, the background research for the economic analysis of water use has proceeded separately (albeit with coordination by the UK Economics Steering Group). As a result, different information is available in relation to the economic characteristics of water uses associated with the pressures. The following integrated analysis attempts to bring together the information available from the pressures and impacts analysis together with the economic analysis of water use to provide as clear a picture as possible. Gaps in the analysis are identified where relevant.

The sections first show the analysis of pressures by economic sector for the RBD. This is based on data for the Scottish area of the RBD but as noted above in most respects pressures in the Scottish part will be similar to those in the English part. Where significant differences are likely, given the economic analysis conducted in the English part of the RBD, these are noted.

The analysis focuses on the economic sectors identified as sources of potential pressure or risk of downgrading identified in the environmental characterisation work that has been undertaken in parallel with this economic analysis. This analysis considered all pressures collectively and does not separate them into rivers, lochs (lakes), transitional, coastal and groundwater as is the case in the separate environmental characterisation work. Instead this report is structured around the main pressure types of point source, diffuse, abstraction and impoundment and alteration to physical habitat. Each pressure is not scaled and it is important to remember that they will vary in magnitude considerably.

Then information related to the pressures for the English part of the RBD is presented. Where this analysis suggests a different conclusion than for the Scottish part, this is noted.

Finally, tables are presented showing the economic characteristics of the main activities causing pressures. Three measures are used. The first is taken from the English analysis of the whole of the Solway Tweed RBD and is reported in terms of Output (measured as Value Added). This facilitates a comparison with the other English RBD economic analysis results. The other measures are based on the value of water use (p/m³*) and the volume of water use. These figures are based on the Scottish analysis of water use, facilitating a comparison with the Scotland RBD report.

Before presenting the results it is important to be clear about what is implied by an ‘economic value of water use’. This analysis provides estimates for the contribution water makes to an industrial process. In undertaking this work with stakeholders it has become clear that there are differences in views about the range of values that should be considered in this analysis. For a full technical exposition of the methodologies and techniques used to establish the values presented please refer to the commissioned research³⁰.

The general approach taken is to recognise that water is one of a number of inputs into a process each of which make a contribution to the final value of the output of the process. In some cases water will become embodied in the product (such as soft drinks) in other cases water will be transformed, warmed, delayed, re-routed, or its assimilative capacity for wastes used. Indeed many processes make more than one use of water simultaneously. In some catchments the same volume of water may be used several times by the same or different kinds of users. There are some catchments, for example, with several hydropower generation facilities that make use of the potential energy of the water at several different points. There may be other examples where the same water is used for the public water supply, is returned to the water body and then used by one or more industrial process. A similar set of considerations can be appreciated when attempting to value recreational uses of water. So far the analysis has attempted to convert the value of water use to a value per litre (the tables are in m³). In some cases this simply does not adequately illustrate the value of use in particular locations and for particular process. In these cases local knowledge and experience should be brought to bear. Over the coming years other means of illustrating the value of water use will be explored. For the time being we are fortunate in having a number of sector specific case studies and reports provided by sector representatives for both Scotland and England³¹.

Table 4 shows how the economic activity of different sectors is associated with the risk of a water body failing to meet good status. Much of the risk is concentrated in certain sectors as can be seen from this table where the three sectors with the greatest number of impacts (highlighted in red) account for almost three quarters of all impacts. Of these three the agriculture, forestry and fishing sector alone accounts for three out of ten risks (mostly associated with diffuse pollution and morphological changes to water bodies). This is followed closely by Energy and Water Supply with almost a quarter of all risks of failure, which are associated with abstraction and flow regulation. Around one in six risks are associated with sewage and refuse disposal and the vast majority of these are related to point source discharges.

There are some risks for which it has not been possible to attribute to a particular sector. These have been allocated to a ‘not identified’ sector. The sector ’other’ refers to identified pressures that are from the rest of the economy; these would include things such as flood defence walls, urban development and land claim.

Each type of pressure is dominated by particular sectors (highlighted in green). Table 4 shows that most impacts from abstraction emanate from the energy and water supply sector, while most diffuse pollution risk comes from agriculture. Most flow regulation risk is associated with electricity generation and agriculture is the main source of physical alterations in the form of drainage and land reclaim. The largest cause of point source discharge is waste water treatment. The concentration of certain sectors within certain pressures suggests that the remediation of the pressure within those sectors will be an important early focus for identifying cost effective measures in affected water bodies.

A further use of this analysis will be in helping to frame the tools we develop to assess the most cost effective combination of measures in water bodies. The more pressures of different types from different sectors faced in any particular water body the more complex the decision-making process is likely to become.

Table 5 considers the number of pressures on a water body and shows how many water bodies are affected by multiple pressures. The more pressures per water body the more potentially complex the likely solutions. If there are fewer pressures there will be a smaller number of possible measures that would combine to achieve the required status and the selection of the most cost effective combination is likely to be more straightforward.

Fortunately, the situation in Solway Tweed is that more than 70 percent of all water bodies face only three or fewer pressures. Indeed only two water bodies have more than 10 pressures.

Table 5 Total number of pressures per water body for all water bodies at risk (Scottish Rural Areas only)

Note: There are 212 identified water bodies in the Solway Tweed RBD and all of those are at risk or likely to be at risk in 2015

This distribution of pressures is also shown in Figure 4. This indicates that there are relatively few waterbodies which are subject to ‘multiple pressures’ (more than four or five). This increases the likelihood of a more straightforward solution.

There are a number of water bodies with multiple pressures emanating from the same sector. This implies that the means by which the pressure might be alleviated could come from the sector itself. Where, for example, a standard set of measures could be applied to reduce the number or complexity of the measures under consideration thereby making the assessment process more manageable. Also, as upstream pressures are mitigated this (to a certain extent) will lessen the seriousness of downstream impacts.

Figure 4 Cumulative percentage of water bodies with at risk pressures in the Scottish segment of the RBD

There is no similar analysis at present of the pressures in the English area of the RBD, however this work is planned to be undertaken in 2005 through the refinement of the river basin characterisation exercise.

The following sections analyse the economic use of water made by each of the sectors reported as being the sources of pressures and impacts on water bodies. The commissioned research further builds on this and can be accessed on the SEPA and DEFRA websites.³²