Establishing physico-chemical reference conditions in Mediterranean streams according to the European Water Framework Directive

Type-specific physico-chemical reference conditions are required for the assessment of ecological status in the Water Framework Directive context, similarly to the biological and hydro-morphological elements. This directive emphasises that natural variability of quality elements in high status (reference condition) needs to be quantified. Mediterranean streams often present a marked seasonal pattern in hydrological, biological and geochemical processes which could affect physico-chemical reference conditions. This study establishes general physico-chemical reference conditions (oxygenation, nutrient, salinity and acidification conditions) for different Mediterranean stream types. 116 potential reference sites located in 23 Mediterranean catchments in Spain were sampled in spring, summer and autumn in 2003. All sites were subjected to a screening method for the selection of reference sites in Mediterranean streams (Mediterranean Reference Criteria) and classified using a pre-established stream typology that establishes five different stream types (temporary streams, evaporite-calcareous at medium altitude, siliceous headwaters, calcareous headwaters and large watercourses). Reference conditions (reference value and reference threshold equivalents to high-good class boundary) were calculated using two different methods according to the availability of reference sites: the reference site 75th percentile approach of all reference sites and the 25th percentile of the population approach. The majority of the studied potential reference sites (76 out of 116) were selected as reference sites. Regarding type-specific reference conditions, only siliceous headwaters could be considered different from the rest of stream types because lower conductivity and pH. All reference stream types presented seasonal differences as regards some parameters, except for temporary streams due to the high natural variation of this stream type. For those parameters which presented seasonal differences in a specific stream type, the least restrictive values were proposed as reference conditions.     

Monitoring,river restoration and the Water Framework Directive

Monitoring is an important aspect of any procedure that seeks to determine whether a technique has worked effectively. The river restoration process is no different. Unfortunately, monitoring is often not undertaken due to constraints on time and resources, as well as the commonly held belief that river restoration is inherently a good thing and, as a result, monitoring is unnecessary. There are many reasons to monitor projects and among the most important is the need to learn from experiences and for regulatory compliance. This paper examines the issues associated with the monitoring of river restoration schemes. In particular, it details monitoring selection models focusing on those associated with ecology and geomorphology. The paper also considers the requirements of monitoring schemes that will help deliver the goals of the Water Framework Directive (WFD).     

Assessing remotely sensed chlorophyll-a for the implementation of the Water Framework Directive in European perialpine lakes

The lakes of the European perialpine region constitute a large water reservoir, which is threatened by the anthropogenic pressure altering water quality. The Water Framework Directive of the European Commission aims to protect water resources and monitoring is seen as an essential step for achieving this goal. Remote sensing can provide frequent data for large scale studies of water quality parameters such as chlorophyll-a (chl-a). In this work we use a dataset of maps of chl-a derived from over 200 MERIS (MEdium Resolution Imaging Spectrometer) satellite images for comparing water quality of 12 perialpine lakes in the period 2003-2009. Besides the different trophic levels of the lakes, results confirm that the seasonal variability of chl-a concentration is particularly pronounced during spring and autumn especially for the more eutrophic lakes. We show that relying on only one sample for the assessment of lake water quality during the season might lead to misleading results and erroneous assignments to quality classes. Time series MERIS data represents a suitable and cost-effective technology to fill this gap, depicting the dynamics of the surface waters of lakes in agreement with the evolution of natural phenomena.     

Stakeholder involvement and public participation: a critique of Water Framework Directive arrangements in the United Kingdom

Expert consensus regarding public consultation and participation on environmental matters favours a multilevel approach: the process is much more likely to succeed when those consulted can relate to the boundaries, scale and the local nature of the issues. The Water Framework Directive requires those with the responsibility for river basin management planning to engage with stakeholders and the general public when such plans are being developed. Examination of the arrangements for public participation in the regions of the United Kingdom shows a marked variation in the interpretation of the Directive that may leave the general public residing in England and Wales at a significant disadvantage. In both Scotland and Northern Ireland involvement by the general public is planned at a much more local level through groups established specifically for that purpose. Arrangements at local level in England and Wales are focused on narrower existing liaison arrangements in place before the implementation of the Directive.     

Challenges to the Implementation of the Water Framework Directive in Scotland: A Personal View

The Water Framework Directive was implemented in December 2000 and has to be transposed into Scottish legislation by 2003. The Directive provides a major opportunity to enhance the water environment of Scotland and to improve its management through the implementation of river-basin management planning with stakeholder and public engagement and the delivery of a programme of environmental-improvement measures to deliver good ecological status. Whilst the Directive provides unparalleled opportunities, there are significant challenges to its successful implementation in Scotland, where a step-change in managing the water environment will be required. This paper explores some of the challenges which include technical aspects, scale and timing issues, and capacity limitations.     

Using multi-criteria analysis to explore non-market monetary values of water quality changes in the context of the Water Framework Directive

The EU Water Framework Directive represents a major change in the management of water resources and sets ambitious ecological objectives for all European waters. In the Directive, the economic assessment of the non-market environmental benefits of water quality improvements plays a crucial role. Studies valuing these benefits are now appearing in the literature, applying stated preference valuation techniques. However, these techniques are often criticized for providing only narrow mono-criterion information to the decision-making process. The research presented here builds on a recent line of investigation that combines monetary stated preference tools, in this case a choice experiment, with multi-criteria analysis, in this case the Analytical Hierarchy Process (AHP). We argue that the AHP can contribute to a better understanding and interpretation of the choice experiment results by exploring the criteria involved in respondents' trade-off between the attributes. The AHP provides relevant insights for the application of use-based water quality ladders in the valuation of environmental benefits in the context of the WFD. Results also show the importance of the spatial dimension of preferences for water quality.     

Dissolved metal background levels in marine waters, for the assessment of the physico-chemical status, within the European Water Framework Directive

The European Water Framework Directive (WFD) has, as its ultimate aim, a reduction in the concentrations of hazardous substances in the marine environment, i.e. 'background' values. Hence, the determination of natural background levels of heavy metals, to distinguish between natural element concentrations and anthropogenically-influenced concentrations, is highly relevant. Some studies have shown the convenience in the derivation of local background levels, especially if they are necessary for environmental assessment. Nevertheless, although such studies exist for sediments, there are only a few previous investigations on metal background values in sea water. Likewise, there is not any standard procedure to determine such levels in waters, nor general agreement on the statistical methodologies to be applied. In this contribution, background levels of heavy metals (As, Cu, Mn, Ni, Pb and Zn), in estuarine and coastal waters within the Basque Country (northern Spain), according to ranges in salinity, are estimated using statistical tools. Ni and Pb have been considered elsewhere (2455/2001/EC) as priority substances under the WFD. Hence, this approach can assist further in the determination of water reference conditions, to assess chemical and physico-chemical status in other European countries; this, affects, ultimately, the ecological status, as defined within the WFD.     

Maximum likelihood mixture estimation to determine metal background values in estuarine and coastal sediments within the European Water Framework Directive

Some of the recently derived European Directives, such as the Water Framework and Marine Strategy, have, as ultimate aims, to achieve concentrations of hazardous substances in the marine environment near background values. Hence, the determination of natural background levels, in marine sediments, is highly relevant. The present study proposes the use of the maximum likelihood mixture estimation (MLME) to determine regional background levels and upper threshold of metal concentration, with the Basque Country as a case study (with a data set of 575 samples, from estuarine and littoral areas, including both intertidal and subtidal sediments). The heuristic procedure is applied with unimodal data distributions (Cd, Cr, Fe and Ni) and the mixture density estimations, based upon maximum likelihood, are carried out with polypopulational data distributions (As, Cu, Mn, Hg, Pb and Zn). The upper limits of the distribution are proposed, as the limits between 'High Status' and 'Good Status' (according to the Water Framework Directive terminology). The regional upper limits were 0.45 microg g(-1) for Cd, 71 microg g(-1) for Cr, 53,542 microg g(-1) for Fe, 57 microg g(-1) for Ni, 24 microg g(-1) for As, 64 microg g(-1) for Cu, 447 microg g(-1) for Mn, 0.27 microg g(-1) for Hg, 66 microg g(-1) for Pb, and 248 microg g(-1) for Zn. The results from this study can assist further in the determination of sediment reference conditions, to assess chemical status, within the above-mentioned directives; likewise, it will be studied as a useful methodology in determining regional metal backgrounds in other European countries.     

Implementing the requirements of the Water Framework Directive for rural water supply schemes in Scotland

In a project pioneering the implementation of the European Union Water Framework Directive in Scotland, a programme of local stream flow gauging in Lochaber demonstrated that low flow yields in the sources were greater than predicted by standard methodologies for ungauged catchments in the UK. This meant that the abstraction required for the water treatment works represented an acceptable proportion of the yield, and complied with Scottish Environment Protection Agency guidance for maintaining good ecological status in the catchments. Development of new sources with dams, pumping stations and pipelines was avoided, thus reducing costs and environmental impacts. A programme of stakeholder consultations was carried out throughout the Water Order application process and agreement on proposed abstractions was reached with over 20 stakeholders.     

The social benefits of restoring water quality in the context of the Water Framework Directive: A comparison of willingness to pay and willingness to accept

The Water Framework Directive (WFD) is by far the most important piece of water legislation in Europe for the coming decades. Its main aim is to achieve “good ecological status” for all water resources by 2015. The economic valuation of the non-market benefits derived from improving water quality is an important input in assisting the design and implementation of efficient and effective water management policies. In this study, the contingent valuation method has been applied with a double purpose. On the one hand, we have estimated the value of a hypothetical improvement in water quality of a river asking individuals about their willingness to pay, and on the other hand, the issue of exemptions contemplated in the WFD has been addressed surveying people on their willingness to accept compensation if projected improvements were not carried out. Finally, a comparison of costs and benefits in a cost-benefit framework shows that the net present value of the water quality policy is positive both if we consider willingness to pay estimates as willingness to accept estimates, therefore this policy appears desirable from a social perspective.     

River water quality of the River Cherwell: an agricultural clay-dominated catchment in the upper Thames Basin, southeastern England

The water quality of the River Cherwell and a tributary of it, the Ray, are described in terms of point and diffuse sources of pollution, for this rural area of the upper Thames Basin. Point sources of pollution dominate at the critical ecological low flow periods of high biological activity. Although the surface geology is predominantly clay, base flow is partly supplied from springs in underlying carbonate-bearing strata, which influences the water quality particularly with regards to calcium and alkalinity. The hydrogeochemistry of the river is outlined and the overall importance of urban point sources even in what would normally be considered to be rural catchments is stressed in relation to the European Unions Water Framework Directive. Issues of phosphorus stripping at sewage treatment works are also considered: such stripping on the Cherwell has reduced phosphorus concentrations by about a factor of two, but this is insufficient for the needs of the Water Framework Directive.     

Urban diffuse pollution: key data information approaches for the Water Framework Directive

The Water Framework Directive (WFD) provides a coherent structure within which the problems of diffuse urban pollution can be effectively tackled and managed. The context of impermeable surface water quality within the terms of the Directive are outlined, and the pollutant sources and loadings associated with various urban land uses are identified. Stormwater flows and quality are sufficient to prejudice any ‘good’ ecological potential, particularly in terms of chronic receiving water sediment toxicity. A simple volume–concentration method for the prediction of pollutant loadings and impact assessment on a subcatchment scale is described and discussed.     

Social preferences and economic valuation for water quality and river restoration: the Segura River,Spain

The Water Framework Directive (WFD) aims at improving the ecological status of the water bodies in Europe. In this context, some rivers are currently being restored and, in accordance with this Directive, the restoration actions have to be evaluated from a socio‐economic approach. This work applies the Choice Modelling method to the WFD provisions for river restoration. This method proves to be useful for the economic valuation of the restoration measures, as well as a very important tool for people's public participation. In this sense, the water quality improvement has been defined as a priority action from a social point of view. Moreover, the method used has provided answers to both basic questions included in the WFD: the calculation of the economic value of the Segura River's ecological flow, the decrease of which would pose an environmental cost, and the estimation of the environmental income generated by this river.     

Predicting faecal indicator fluxes using digital land use data in the UK's sentinel Water Framework Directive catchment: the Ribble study

The Ribble drainage basin is the single UK sentinel study area chosen for examining the implementation of the EU Water Framework Directive (WFD 20/60/EC). The study which has generated the data for this paper was initiated to quantify 'catchment-derived' fluxes of faecal indicators originating from both point and diffuse sources to inform the competent authorities on the potential for, and prioritization of, further options for reducing the faecal indicator loadings to this crucial coastal environment. It represents the first UK drainage basin-scale 'profile' of faecal indicator sources as recommended by WHO [1999. Health Based Monitoring of Recreational Waters: The Feasibility of a New Approach; the "Annapolis Protocol". World Health Organisation Geneva, Switzerland; 2003. Guidelines for Safe Recreational-Water Environments Volume 1: Coastal and Fresh-Waters. World Health Organisation Geneva, Switzerland] and incorporated into current drafts of the revised Bathing Water Directive [Anon, 2004. Council of the European Communities Amended proposal for a Directive of the European Parliament and of the Council concerning the management of bathing water quality. Brussels 23rd June]. This paper focuses on the relationships between land use and faecal indicator organism concentrations in surface waters within this very large drainage basin (1583 km2) containing some extensive urban areas. A geographical information system comprising readily available digital elevation, remotely sensed land cover and digital map data was used to generate the land use variables for subcatchments draining to 41 locations across the study area. Presumptive concentrations of coliforms, Escherichia coli and enterococci (colony forming unit (cfu) 100 ml(-1)) were measured at each location on at least 20 occasions over a 44-day period within the 2002 bathing season. The sampling programme targeted hydrograph events. Hydrometric records were used to allocate results as either base flow or high flow. At each site, geometric mean faecal indicator organism concentrations were significantly elevated at high flow compared to base flow. Stepwise regression modelling produced statistically significant models predicting geometric mean base and high-flow faecal indicator organism concentrations from land use variables (r2: 49.5-68.1%). The dominant predictor variable in each case was the proportion of built-up land in subcatchments, suggesting that this land use type, with associated sewage-related inputs, is a critical source of faecal indicator organisms in this drainage basin.     

Eutrophication of Tamar Lakes (1975–2003): a case study of land-use impacts, potential solutions and fundamental issues for the Water Framework Directive

Tamar Lakes is comprised of two reservoirs, which are located in South West England and in the headwaters of River Tamar at approximately 135 m above ordnance datum. Upper Tamar Lake (UTL) is a direct feed source reservoir of potable water in North Cornwall. Immediately following completion in 1975, UTL was subject to intense blue‐green algal blooms that continue to the present. These blooms create operational problems for water treatment, especially in hot‐dry years. Lower Tamar Lake (LTL) was constructed as a water supply reservoir in 1819 and became obsolete following UTL coming on‐line. Detailed water quality investigations over a period of some 28 years have confirmed the source of nutrient enrichment that fuels the algal blooms to be agriculturally derived, corresponding with a substantial increase in livestock farming. Associated poor land management practices, such as extensive field drainage and inappropriate slurry disposal to land, are linked with substantial elevations in organic contaminants such as ammonia, biochemical oxygen demand (BOD) and suspended solids (SS) during rainfall events. Evidence demonstrates that both reservoirs act as primary treatment lagoons, substantially reducing the worst of these pollutants and providing significant environmental gain. The implications of the Common Agricultural Policy (CAP), the Water Framework Directive (WFD) and regulatory monitoring are discussed in relation to resource management.