Executive Summary

…..3.8

Introduction

Z. Kundzewicz, F.F. Hattermann and A. Becker

1.1 What is this document for?

The Water Framework Directive (WFD), which came into force in December 2000, arranges a framework for actions of the European Communities in the field of water policy, with the key objective of achieving a “good water status” for all waters in the European Union (EU) by 2015. The Directive imposes legal obligations for the authorities in EU Member States. In order to assist the EU Member States and, in particular, the water managers within river basin districts in implementing the Directive, a number of activities have been launched. The EU Member States, Norway, and the European Commission have developed a common strategy for supporting the coherent and harmonious implementation of WFD, which has led to the publication of practical guidance documents on various technical issues related to the Directive. In addition, a number of scientific efforts at the European level and associated with the WFD have been made with the aim of providing the scientific support in implementing the Directive.

The objective of the present document is to offer guidance to water managers on the model-supported implementation of the Water Framework Directive at the level of a river basin district and at other levels (such as sub-basins, national, or international scale in the case of international river basins). The document is a deliverable of the Concerted Action “HarmoniCA” (Harmonised Modelling Tools for Integrated Basin Management), and in particular, it’s Work Package 3 (WP3). The HarmoniCA Project has been launched within the Sixth EU Framework Programme with the overall objective of creating a forum for unambiguous communication, information exchange, and harmonisation of the use and development of Information and Communication tools (referred to as IC-tools or ICT) relevant to river management, and the implementation of the WFD (see http://www.harmoni-ca.info). Work Package 3 of the HarmoniCA Project was conceived to promote the development of a harmonised general methodology (planning framework) for water management along the lines of the Directive.

In addition to HarmoniCA, there are further EU projects providing scientific support in implementing the Directive, such as those belonging to the CatchMod (Integrated Catchment Water Modelling) Cluster with the objective of developing common harmonised modelling tools and methodologies for the integrated management of water at the river basin scale, cf. http://www.harmonit.org/links/catchmod.htm. The CatchMod Cluster groups a number of projects from the “Harmon[y]” family and some other projects. The HarmoniQuA (Quality Assurance) Project provides methodological framework for quality assurance in modelling and model applications, cf. http://harmoniqua.wau.nl. The HarmoniCOP (Harmonising Collaborative Planning) Project, aims to improve participation in water management, cf. http://harmonicop.info. The following projects also play useful roles and provide guidance: the Harmoni-RiB (Harmonised Techniques and Representative River Basin Data for Assessment and Use of Uncertainty Information in Integrated Water Management), cf. www.harmonirib.com, the HarmonIT (project aimed at the development and implementation of a European Open Modelling Interface and Environment), cf. http://www.harmonit.org, the EuroHarp (Towards European Harmonised Procedures for Quantification of Nutrient Losses from Diffuse Sources), cf. http://www.euroharp.org, TransCat (project dealing with Integrated Water Management of Transboundary Catchments), cf. http://www.transcat-project.net/index.php, and the BMW (Benchmark Models for the Water Framework Directive), cf. target=_blank>www.environment.fi/syke/bmw. for specific modelling related issues

The present document complements the material provided by working groups of water managers and other experts in the field of water in Europe, established to develop several guidance documents (GD 1 to 13) in the framework of the “Common Implementation Strategy” (CIS) for the implementation of the WFD. In particular, the present document refers to the Guidance Document No. 11 (GD 11) on Planning Process (EC, 2003), which presents a general overview of the whole planning cycle and provides recommendations for its successful implementation. As explicitly stated in the foreword to the latter publication, “[it] is a living document that will need continuous input and improvements…”. The present document reacts to this invitation and offers complementary contribution: guidance on model-supported implementation of the Directive; and in particular on the use of models for the planning measures and integrated river basin management. It should help water managers to better understand how models may be used for planning purposes, while special attention should be given to the problem of predicting an uncertain future, one very likely to differ from the present.

This could be useful, since the GD 11 does not focus on modelling. The considerable potential and challenges in modelling are neither explained nor discussed in that guidance document that only makes ten references to “model[s]” or “modelling” (EC, 2003). This corroborates the observation that, indeed, there is a niche for projects like HarmoniCA. It is worthwhile to follow in what context the GD 11 (EC, 2003) mentions models and modelling.

Modelling is mainly referred to in a rather short section (4.5: The appropriate toolbox). The GD 11 states that models exemplify the systems approach to water resources planning. It observes that models permit a definition and evaluation of numerous alternatives that represent various possible compromises among conflicting groups, values, and management objectives (such as options for engineering structures, operating and allocating policies, and different assumptions made in the analysis) in physical and economic contexts. In particular, a rigorous and objective analysis should help to identify the possible trade-offs between quantifiable objectives so that further debate and analysis can be more informed. As stated in (EC, 2003), “models can represent, in a fairly structured and ordered manner, the important interdependencies and interactions among the various control structures and users of a water resources system.” Models are viewed as tools capable of answering well-posed questions about the behaviour of the system being studied. However, it can be useful to feed answers derived from the models back into questions and to examine whether or not rephrasing the original questions is necessary. That is, models can be used a in two-way process: they produce information that may be channelled into decision making (formulation of plans) or they produce information that is fed back to aid in redefining the problem (EC, 2003).

The present document consists of five chapters. After the brief general introduction, the opening chapter explains the objective of the document and provides brief information on the Water Framework Directive. Chapter 2 explains the planning process of implementing the Directive and demonstrates how models can help in this context. This refers to identifying the current status and setup of monitoring programmes, and to designing, setting up, implementing, and evaluating programme measures. Chapter 3 introduces a primer on modelling, tailored to the needs of practitioners. It provides an easy introduction to modelling and then proceeds to explaining several specific technical issues related to the modelling process, such as model selection, models for impact analysis, integrated modelling, problems of model calibration and validation, special requirements for stakeholder participation, uncertainty assessment and quality assurance aspects. Here, references are made to relevant documents and guidelines prepared in the HarmoniCA project and other EU projects, particularly from the CatchMod Cluster. Finally, Chapter 5 breifly presents six case studies from different parts of Europe to illustrate the practical applicability of the planning framework in the WFD implementation. They are very important for illustrating how concepts from earlier parts of the document are applied to real-world situations. The case studies cover several aspects of mesoscale river basin management, water quantity and quality issues, and the role of modelling, with two case studies located in pilot river basins.

The primary targeted audience is authorities entrusted with implementing the WFD. First and foremost, these are water managers in river basin districts, but also other stakeholders with stakes and/or interest in the implementing: the Directive, such as landowners, decision makers at different levels (from central government, via provinces through to municipalities and counties), water users, scientists, educators, NGOs, nature protection activists and environmentalists, farmers, media, and the broader public. The overall aim is to fulfil the various and varying demands of all parties interested in and affected by the implementation of the Water Framework Directive. It is hoped that this document contributes to improving the understanding of modelling aspects and facilitates the planning process for implementing the Directive. The emphasis lies on practical aspects, hence the material refers to practice, and case studies illustrate implementing the planning process in practice.

The ideas is to keep the document simple in structure, content, presentation, and terminology to keep it readable for a broader, practice-oriented audience.We avoid using the original, formal and legal language of the Directive without dropping technical contents of the message. The aim is to keep the present material in a complementary and not in a repetition fashion vis-à-vis the Guidance Document 11 (EC, 2003) while providing additional material, with particular references to modelling, and seeking synergy. The superstructural question document aims to assist in answering is: How to manage water in river basin districts in order to meet the WFD objective.

1.2 The Water Framework Directive – a challenge

On 22 December 2000, the Water Framework Directive (WFD) was published in the official Journal of the European Communities [I.327/1-72], after it had been accepted as Directive 2000/60/EC by the European Parliament and the Council on 23 October 2000, hence coming into force (EC, 2000). The Directive arranges a framework for analysing, planning and managing water resources at river basin scales, with the major objective of achieving at least (par. 26, EC, 2000) “good water status” for all waters by the year 2015.

The purpose of the Directive (Art. 1, EC, 2000) is to establish a framework for the long-term protection of freshwaters, preventing future deterioration and protecting and enhancing the status of ecosystems (aquatic, terrestrial, and wetlands); to promote sustainable water use; to ensure reduction of pollutant loads; and to contribute to mitigating floods and droughts. As stated in paragraph (25) of the Directive, environmental objectives should be set to ensure that good status of surface water and groundwater is achieved throughout the Community and that deterioration of waters is prevented at Community level. The objective of achieving good water status should be pursued for each river basin (par. 33, EC 2000).

The Directive is a challenge to EU nations and their water sectors. In several areas the current quality of water is far below the WFD target, so long-lasting and costly efforts are required to reach good status of all waters by 2015. The principles of the Directive have been greeted by the increasingly environment-friendly societies of EU nations, yet the WFD is not easy to implement under a variety of national conditions, different legislations, standards, guidelines, traditions, etc.

The WFD creates a legal obligation for the authorities in EU Member States to organize water management within river basin districts (rather than within administrative units). The Directive provides relevant advice for planning processes. Preamble 13 of the Directive highlights the possible diversity of conditions and needs in the various river basins (and districts), which require different specific solutions. This diversity should be taken into account in implementing of the WFD. Further, Preamble 13 states that decisions should be made as close as possible to the locations where water is affected or used (need for competent, decentralized, grassroots decision making in accordance to the subsidiarity principle). Preamble 28 emphasises the time lag in the processes of renewing water resources (particularly long for groundwater) to be taken into account in the planning measures for achieving the good water status. It can take a very long time to reverse a trend towards increasing groundwater pollution. Article 4 tackles environmental objectives, Article 5 deals with assessing the current status of waters in a river basin district, while Article 8 regulates monitoring. The comprehensive Article 11 of the WFD defines some basic requirements concerning the programme measures, established in order to achieve the environmental objectives of the WFD. The WFD requires Member States to produce a management plan for each river basin district (Article 13) involving stakeholders in plan development. The plans should envisage reporting mechanisms to the Commission and public (Article 15).

Integration is indeed a key concept underlying the Water Framework Directive for regulating the management of water protection within the river basins and the river basin districts (EC, 2003). Integration is interpreted in a very broad sense in the WFD, much broader than in the classic integrated water management approach, where the scope was typically reduced to joint consideration of surface water and groundwater and/or of water quantity and quality aspects. The Directive jointly considers, quality, environmental, ecological, and quantity objectives for protecting valuable aquatic ecosystems and ensuring a general good status of waters. It embraces integrating all water resources (fresh surface water and groundwater), and all water uses, functions and values. The notion also integrates disciplines, analyses and expertise (hydrology, hydraulics, ecology, chemistry, soil sciences, agronomy, forestry, technology, engineering and economics) to aid in implementing the Directive in the most cost-effective manner. The Directive also requires integrating water legislation into a common and coherent framework and consideration of significant management and environmental aspects. It calls for using a wide range of measures, including economic and financial instruments, e.g. water pricing. Furthermore, integrating stakeholders and the civil society in decision making is required, as well as integrating different decision-making levels (local, regional or national), and water management from different Member States in the case of international basins.

The need for integrated river basin management has risen because managing environmental processes independently (without integration) may not be sufficient and may not lead to optimal decisions. Due to complexity of processes and systems involved, managers turn to integrated models and decision support systems.

The recent understanding of integrated water resources management (IWRM), as defined by the Technical Advisory Committee of the Global Water Partnership, reads (GWP 2000): “Integrated water resources management is a process, which promotes the coordinated development and management of water, land and related resources in order to maximize the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems.”

The Key words here are “process”, “coordinated development and management of water, land and related resources”, considering the relationship with “economic and social welfare” and equity, and “the sustainability of vital ecosystems”. It clearly points in the direction of “Integrated River Basin Management” (IRBM).

Mostert (1998) describes five aspects capable of causing problems in the application of IWRM:

This list can be extended by adding further elements, such as:

The distinction between “integrated” and “traditional” management of water resources or river basins has to do with the scope and sphere they operation in. The latter is typically sector-oriented (water supply, irrigation, hydropower, etc.) and focused on the satisfaction of the demands perceived within each sector. On the other hand, the former attempts to take a cross-sector approach and to focus on integrated management of the available water and land resources, accounting for their spatial and temporal variability and associated uncertainties .

This necessitates the decision-making procedure to include a coordinated inter- and cross-disciplinary dialogue between the social, natural and engineering sciences while retaining the distinctive depth of the individual disciplines. It should support a dialogue between stakeholders and decision makers on the one hand, and scientists, representatives of governmental Environment Protection Agencies (EPAs) and non-governmental organizations (NGOs) on the other to develop a process of social learning. What emerges is the most appropriate compromise alternative, which will then be implemented.

This general concept is accepted as the IWRM Paradigm, adopted by the European Water Framework Directive (EC, 2000), forming core element of any future planning methodology.

According to Article 11 and Annex VI of the WFD (EC, 2000), basic and supplementary measures should be implemented in order to achieve environmental objectives of the Directive. The list of basic measures, the minimum requirements to comply with, consists of the following EU regulations introduced in the past decades (in chronological order):

Further legislative acts, such as the recent Floods Directive, should be also considered.

In cases where these measures do not suffice to reach the environmental objectives defined under Article 4 of the Directive (EC, 2000), Member States are entitled to supplementary measures (cf. Annex VI part B of WFD). They comprise (EC, 2000):

The measures listed above should be considered pragmatic action alternatives, established with the purpose of reaching environmental objectives. Any other actions resulting from different sectoral policies can also be considered measures and implementations (falling under the item (xvii) above, i.e. other relevant measures). Actions such as urban development plans, best agricultural practices, and flood risk plans, can be considered “supplementary” measures in regard to meeting environmental objectives.

The Directive provides a long-term policy basis for water management with clearly defined interim objectives. It delineates a road map of objectives to be met in the future, drawing clear deadlines for each of the requirements to add up to an ambitious overall timetable. The period to 2015 refers to the Directive proper, while the second period (2015-2027) will be managed with due consideration of the experience gained in the first period. The key milestones and deadlines for achieving them are listed below (Table 1.1).

Table 1.1: Key milestones of the European Water Framework Directive (Issues foreseen to have been completed already are shown in italics).

2 How can models help implementing the Water Framework Directive?

F.F. Hattermann, A. Becker, Z.W. Kundzewicz, Y. Laurans, S. Muhar, R. Sonsini-Sessa, P. Stalnacke, P. Willems

2.1 Framework for model-supported participatory planning of measures in implementing the Water Framework Directive

2.1.1 The planning process of implementing the Water Framework Directive

The general structure of the planning process to implement the Water Framework Directive contains the following main components identified in the GD 11 (EC, 2003) (Table 2.1):

Table 2.1: General structure of the planning process to implement the Water Framework Directive.

A short explanation of the particular components is offered in the sequel.

(o) Setting the scene is an initial phase that aims at defining the system of interest (such as a river basin or a river basin district), and describing the problem to be solved and the goals of the plan. This includes the overall objective of “good water status” and sustainable development, as required by the WFD. For that purpose, the system boundaries and the time and space domains should be defined. In addition, the authorities, stakeholders, sectors involved, and the institutional and legal framework of the plan should be identified.

(i) Assessing the current status and preliminary gap analysis includes describing the “characteristics of each river basin district”, in particular those of the water bodies, including artificial and heavily modified water bodies, and establishing reference conditions. Here, protected areas must be designated and registered, and an economic analysis of water uses performed. It is necessary to identify significant current and future anthropogenic pressures, to assess their impacts, and to determine which water bodies will be at risk of failing to meet the environmental objectives. This also includes the putting the massive effort needed into preliminary analysis of information and knowledge gaps.

(ii) Setting up the environmental objectives aims at reaching “good ecological status”, “good ecological potential”, and specific objectives. When goals and targets are set, they serve as the foundation for the decision on programmes measures.

(iii) Establishing monitoring programmes is required for implementing the Directive in order to improve our knowledge and understanding of the particular river basin and the determining the risk of failing to meet the WFD objectives. Monitoring can serve as surveillance (for improving determining the water bodies at risk of failing to meet the Directive’s objectives), operation (for checking the progress made in establishing the Directive’s objectives) and investigative measures (to explain why the given body is at risk and to assess the risk).

(iv) Gap analysis means identifying “gaps” by comparing scenarios of future system performance with the “goal” status (e.g. good ecological status). The gap analysis builds on assessing the current status (component i) compared with the environmental objectives of the Directive (component ii). It also uses the future development scenario (Baseline Scenario, a business as usual projection into the future, often computed by with models, see Glossary), which serves as a reference for planning measures.

(v) Setting up programme of measures should identify a feasible set of alternatives for enabling overall goals to be met, while collecting a satisfactory level of possible consensus among the stakeholders. This part of the planning process includes two aspects: determining scenarios and alternative measures. Scenarios mainly deal with future external driving forces in the river basin such as global developments, EU policies, climate change etc. Projections (visions into the future) and assumptions (e.g. by experts) are required to estimate effects and impacts. Many “alternative measures” (action alternatives) can be defined before effects/impacts are investigated and compared. It should be emphasized that economic instruments and pricing policies must be considered as well. This part of the planning process takes into account the principles of sustainable development, of “polluter pays”, “risk taker pays”, “cost recovery”, and “source control rather than the end-of-the-pipe” approach. This is the phase to discuss possible alternatives in a broad participation process .

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(vi) Developing River Basin Management Plans is an essential milestone in the planning process. A plan is a principal mechanism of implementing measures to achieve the WFD objectives by thoroughly evaluating and comparing different measures (alternatives), a task that experts should tackle. This can be essential as some measures are expensive, and the negotiation based on model results preceeding the implementation would facilitate informed decision making.

(vii) Implementing the programme of measures (v) includes preparing the interim report on the implementation.

(viii) Evaluating the success of the implemented measures is an indispensable part of the planning process. It should inform about the progress made to meet the WFD objectives. Indicators like water levels, discharges, water quality characteristics (e.g. N, P), other substances and solutes, BOD, biomass etc., are required to evaluate and compare how the system performs with not measures taken (“do-nothing” option) and what effects (impacts) of all the alternatives (measures) on the system are projected. Stakeholders must define a set of evaluation criteria reflecting the values that underlie their judgments in accordance to the WFD and existing national or regional regulations,. These are the “goal criteria”, e.g. setting the “threshold” values for water levels, discharges, water quality parameters, and ecological criteria not to be exceeded.

(ix) The public should be informed and consulted, and interested parties actively involved early on in the process, e.g. in steps (i), (ii), (iv), (v), (vi), (viii). The concept of measures and River Basin Management Plan, prepared by experts and managers, should be discussed with stakeholders and other experts to get a reaction – of approval or criticism, advice and other comments. Stakeholders can also define measures to be considered (action alternatives). “It’s crucial for the legitimacy of a planning process to start dialogue as early as in the phases of problem defining and setting the agenda” (EC, 2003).

The above components of the planning process are discussed in detail in GD 11 (EC, 2003). It is worth stating that these components do not necessarily have to be followed in rigid succession from (o) to (ix). Even though the planning process is described as a linear sequence of components, several feedbacks and iterative processes are possible and necessary indeed. The planning includes a number of components that depend on each other and should be jointly developed. For instance, informing and consulting the public and actively involving interested parties should already take place in much earlier stages, at best “as early as possible” (cf. discussion above).

The Directive aims at triggering positive changes in the future. The planning must consider future “boundary conditions”, such as development and variability (seasonal and inter-annual) in water availability conditions, quality and demand. Beyond that, changes in land use and wastewater release affecting water availability and quality and thus the ecological status of the water bodies need to be known. This also applies to water demand (water use), subject to change due to technological changes or economic development (including resulting land use and land-cover changes) or to weather conditions. The Baseline Scenario should also take into the projections of the climate change into account. In the planning interval of 2015, climate models are quite consistent in projections of both temperature and precipitation, unlike in later intervals (eg. 2050), when precipitation projections may largely differ between models disagreeing even on the direction of changes. The scenarios should include information about the normal (average) conditions as well as the extreme conditions (e.g. very dry summers). Projections into the future are required in form of scenarios based on model simulations, expert judgments or sometimes reasonable assumptions (e.g. trend extrapolations), on weather conditions (climate) and other external driving forces (e. g. globalization, population dynamics, economic growth, EU policies) over the planning period. The internally consistent scenarios should be interpreted as plausible alternative projections into the future, rather than being treated as crisp and accurate predictions.

The impacts corresponding to each scenario and measure (alternative) have to be estimated. This is generally a simulation step, using calibrated models. If more than one scenario exists, the estimation has to be made for each of them. At the end of this step an impact matrix is produced with elements as values of the indicators derived from each scenario and each alternative to help evaluate the results.

In order to facilitate model support for water managers dealing with the WFD implementation process, it is crucial to make the modelling process structure (see e.g. the five modelling steps as described in Scholten et al. 2004) applicable to the framework for water management suggested in GD 11 (EC 2003), and shown in Figure 2.1.

As it has been identified in the GD 11 (EC, 2003), models are a considerably aid in several components of the planning process to implement the Water Framework Directive. Models are indispensable for impact prediction and what-if analyses (in planning, designing, and managing water resources systems). They are useful in virtually all the steps in the planning process. They turn out to be beneficial and – in a variety of circumstances – indispensable. Models can help us understand and optimize the efficiency of water resources usage.

Figure 2.1: The management approach including the main stages of the WFD implementation process according to GD 11 (EC, 2003)

How to support the planning process outlined in Figure 2.1Figure 2.1 by use of models and in consultation with stakeholders is the core of this guide. The formal methodology is described in the following section.

2.1.2 Framework for model-supported implementation of the Directive

The challenges of the WFD are pointed out in Section 1.2. It is required to bring the water bodies in Europe into a “good chemical and ecological status”, but at the same time to account for cost-effectiveness and to honour the needs and demands of many different stakeholders, and environmental concerns. Thus, carefully planning the implementation is important, combining the nine steps of the WFD (as introduced in GD 11, see Section 2.1.1) and the five typical modelling tasks as described and explained by Scholten et al. (2004).

The framework for model-supported implementation of the Directive should integrate modelling and management to allow adaptation driven by participation, facilitating social learning and supporting decision making (Pahl-Wostl 2002a&b). Such a framework (flowchart for model-supported implementation of WFD) is presented in the sequel (Figure 2.2). Its Main components were developed in (Wenzel, 1999, Soncini-Sessa et al. 2004 and Becker et al. 2005).

The individual steps in the combined planning framework for model-supported river basin management, schematically illustrated in Figure 2.2, will be briefly explained in the following, focusing on “what” has to be done in each step. A general explanation of the “how” is much more difficult to give, because water-related problems where models are applied to support the planning process are very diverse, ranging from operating water storage reservoirs to water quality management in lakes, over salinisation problems to biodiversity loss, etc. Therefore, a selection of case studies will give guidance on how typical water-related problems have been investigated in different European countries using models to support the planning process (see Chapter 6). The case studies cover methodologies to set up a Baseline Scenario (Section 6.2), water supply related problems (see Section 6.3 and 6.4) and water quality related problems (see Section 6.5 and 6.6). Many additional examples show how and when model applications are useful to facilitate water management and also public participation.

Figure 2.2: Framework for model-supported participatory planning of measures and Integrated River Basin Management (planning framework).

The planning framework shown in Figure 2.2 describes the main tasks to be considered for integrating participatory river basin planning and modelling along the first main stages of the WFD implementation. It can be applied to manage and structure the entire implementation process, but also to organize individual modelling tasks. A very detailed methodology for structuring the modelling process as such has been compiled by the EU HarmoniQuA Project (MoST - Modelling Support Tool, see http://www.wise-rtd.info).

Step 1 – Problem description and goal definition: “Setting the scene”

This phase aims at defining the system of interest (river basin or river basin district), describes the problem to be solved and the goals of the plan, including the “good water status” and cost-effective sustainable development, as required by the WFD. In other words, the state of the system has to be characterized, including the relevant drivers and pressures. Looking at the entire WFD implementation process, this phase corresponds to the first three implementation steps according to GD 11, namely

• Assessing the current status and preliminary gap analysis,
• Setting up the environmental objectives, and
• Establishing monitoring programmes.

The preliminary gap analysis forms the background information to define and describe the modelling problem (“what to model”), the setup of the environmental objectives is the input to develop a model study plan (“how to model”). For that purpose the boundaries of the system (climate and management) and the time and space domains must be defined, as well as the authorities, stakeholders and sectors involved, (institutional and stakeholder analysis) and the institutional and legal framework of the plan.

The aim of this step is to develop the working concept of the project. Starting from the problem description and goal definition the “means of solution” must be conceived and designed. In principle, a kind of “project proposal” needs to be developed describing how the given task can be solved. This work needs careful thinking, is primarily expert and manager based, and largely is intellectual work. The final concept should be discussed with stakeholders and experts (individually or in a group discussion), to get their approval, advice and comments. “It’s crucial for the legitimacy of a planning process to start dialogue as early as in the phases of problem defining and setting the agenda” (GD 11, EC 2003d). Therefore all activities that may raise consensus must be promoted in this step.

Following Pahl-Wostl 2004 three types of stakeholder and public participation can be distinguished (see also Section 4):

• Information: The lowest form of participation is information.
• Consultation: In the case of consultation different stakeholder groups and the public at large are asked to give their opinion on a management plan / scenario.
• Active involvement: Stakeholders and the public are actively involved in river basin management.

The latter is preferable. It can lead to to a pro-active management regime via a co-production of knowledge and of co-decision making (viz. adaptive management, see Section 4.1), and, in the end, can help to prevent undesirable impacts of unsuitable management measures.

Step 2 – Conceptualisation

The previous step aimed at “setting the scene”, including preliminary gap analysis, defining environmental objectives and setting up a model study plan. This step helps conceptualize the management and modelling problem.

Step 2a – Identification of mIdentification of measures

In this step classes of measures (or actions) possibly allowing the environmental goals to be attained are identified , while accounting for the different stakeholders’ interests. Examples of possible measures are the implementation of reservoirs or sewage treatment plants, changes in water management general, but also changes in land use management (watershed management), establishment of wetlands, and riparian buffer zones. These measures should be sustainable and increase the buffering capacity and resilience of the hydrological system.

A coherent set of measures (following one story line) represents a management alternative. Part of the action identification should be to clearly state “who is doing what and when”. The final scope of the planning process is to identify the set of alternatives that allow the goals of the plan to be reached (the good status of the water bodies) while building consensus among the stakeholders. This step is necessary in order to design models that allow the assessment of the resulting effects/impacts in the simulations to be incorporated and easily activated. Moreover, there should be capacity to adapt the model to new management options.

Step 2b – Criteria and indicator identification

A very sensitive task is to identify criteria and indicators which can be used to describe the water-related problems and to measure the consequences of implementing new management measures.

In addition to the criteria defined by the WFD, and the existing legislation (including national or regional regulations), stakeholders must define a set of evaluation criteria reflecting the values that underlie their judgments. These are the “goal criteria”, such as “threshold” values of water levels, discharges, or water quality and ecological criteria not to be exceeded in order to reach a good status of the water body. It is appropriate to structure the criteria as a hierarchy, starting off with the goal of the plan and iteratively refining it. A comprehensive description of work with various criteria is given in the Verbano case study (see Section 6.4).

Indicators are required to evaluate and compare how the hydrological system behaves without any action taken and in effect of the management alternative(s) i.e. measure(s). Examples for such indicators are water levels, discharges, water quality characteristics, for example N, P, BOD, biomass etc. These indicators also specify the type of model to be applied to investigate the state of the hydrological system.

Identifying evaluation criteria and indicators should result from discussions with the relevant stakeholders and local experts.

If the system is affected by uncertain inputs or by the stochasticity of processes, the indicator values are uncertain making quantitative measures of risk and uncertainty necessary (see Spree river basin study, Section 6.6).

Step 2c – Model setup including calibration and validation

In order to simulate the system response to changes in management or climate and the trajectories needed to quantify the indicators, a site-specific model of the entire system is required. Three sub-steps can be distinguished in building the model (see also EU project HarmoniQuA - Scholten et al. 2004):

(a) model setup;
(b) model calibration;
(c) validation.

Clearly, they belong together and include the aspects of uncertainty assessment and quality assurance. First of all, the decision must be made whether and where models are to be applied and what type of models (e.g., detailed, parsimonious) could be used (see Section 3.2.1, and also the Scheldt river basin case study, see Section 6.3). The most important driver is the required accuracy of the results: if there is demand for very accurate and detailed model results, a more sophisticated model has to be applied, and the relevant data have to be collected accordingly (Højberg et al. 2006).

Model validation results (from comparing observed data and modelling results for periods / locations where the model has not been calibrated) are very important for raising the confidence of the stakeholders in the models and so, for justifying further modelling for the impact analyses. Here it is beneficial to have computer-based illustrations and summary interpretations of simulation results. In any case, a calibrated and validated model for the river basin in question (or hydrological system under investigation) is delivered after this step. The choice of the model types and their degree of detail strongly depends on the indicators defined in step 2b, regulated by the data available to operate the model and the actions selected in step 2a.

It is not mandatory for the model to be mathematical. Another option could be to use knowledge of an expert able to describe the effects a given alternative would induce (such a case is presented in this document for the Möll in Section 6.7). However, mathematical models are frequently used. The validation of the model including sensitivity and uncertainty analyses defines the reliability of the model results (see Section 3.3).

Sometimes two or more models are adopted; e.g., a simpler model for the design of alternatives (see step 3b) and a more complex one for a more accurate estimation of effects (see Section 3.2 and the Scheldt case study in Section 6.3). If this is the case, it is good practice for the first to be a parsimonious version of the second. Similarly, in multi-scale studies the larger-scale study could be based on a simpler (parsimonious) model while in the smaller-scale study a more detailed model is required.

Step 3 – Scenario definition and alternative design (two steps)

In order to set up the programme of measures aiming to reach the good status of the water bodies according to the WFD, projections into the future are required. The first inputs to the model are the driving forces unaffected by the alternatives and variables describing alternative external conditions (e.g. climate change, globalization etc.). Their trajectories are called scenarios, since they describe the background scene on which the alternatives act. Both the scenarios and the management alternatives (the second input to the models) have to be quantitative and the scope of this step is defined by determining them. It may not be necessary to specify just one scenario. Neither is the scenario necessarily deterministic (indicating certainty of the future); it can be stochastic (uncertain) (see also Spree/Havel case study in Section 6.6). For scenario designing see also Section 2.3.2.

Step 3a – Choice of scenario

The scenario(s) may be chosen by experts or obtained by running models that describe the processes producing the driving forces; e.g. the future scenario of rainfall can be produced by a climate model, while the future scenario of land use is often proposed by an expert.

The length of the time horizon defining the scenario must be sufficiently long to observe all the types of possible significant events in the system (e.g. 20 or 50 years). There may be different scenarios for designing alternatives (design scenarios) and for estimating impacts.

Step 3b – Design of the programme of measures (action alternatives)

The term “measure” or “action alternative” is used to emphasize that system modelling serves the investigations of “alternative measures”. Very often ,it is the case that the only measures (alternatives) considered during a real design process are those suggested by the stakeholders and the manager’s experience. This is a convenient starting point, but one should consider all alternative measures obtained by all combinations of actions identified in step 2 leading to achieving the environmental objectives (“good water status” proposed by the WFD). Generally, the resulting number of alternatives is fairly large. Therefore it is necessary to screen them in a way that optimal combinations in terms of benefit for the different stakeholders are selected (the so-called Pareto optimality, where subordinate alternatives are removed, see Soncini-Sessa, 2005). For details see the Verbano case study in Section 6.4.

Step 4 – Simulation and estimation of effects/impacts

The effects/impacts resulting from each scenario and measures (alternative) have to be estimated by computing the values the indicators take for each alternative. This is generally a simulation step where calibrated models are used. If more than one scenario exists, the estimation has to be made with respect to each one of them. At the end of this step an impact matrix is produced whose elements are the indicator values for each scenario and alternative. It serves to evaluate and compare results (see Figure 2.3).

Figure 2.53: Impact matrix illustrating the impacts of different planning alternatives on specific criteria (Wenzel 2005). Translation of German terms: Versorgungssicherheit – Supply reliability; Mindestabfluß – Least discharge; Wasserwerke – Water supply units; Kraftwerke – Water power units.

Step 5 - Evaluation of the alternatives

Given the Impact Matrix, the goal of this step is to determine the “value” that each sector assigns to each alternative (in general, this “value” may not be related to the indicator values in a simple way). A number of evaluation techniques exist for assisting the analyst in reaching this goal (e.g., multi-attribute value theory and analytic hierarchy process, see Soncini-Sessa, 2005).

When only one decision maker and one stakeholder exist, the optimal alternative can be easily found by ranking the alternatives with respect to their values compared with the adopted goal criteria and indicators, after which the procedure terminates. If either the number of decision makers, the number of stakeholders, or both, are greater than one, a different ranking of alternatives is found for each stakeholder or decision maker at the end of this step. For this reason, the decision process is not completed yet and proceeding with the following step is necessary.

Step 6 – Comparison and negotiation

The optimum result of this step is identifying a set of measures (action alternatives) that can be perceived as a fair trade-off between different stakeholders' interests without encounting anyone’s opposition and taking Articles 4.5-7 of the WFD into account. If such an alternative cannot be found, the step can be brought to an end by identifying the alternatives that live up to the environmental objectives (“good water status”) and gather a broad (yet imcomplete) consensus amongst the stakeholders. Supporters and opponents of each of these alternatives must be identified. The process begins by briefing each stakeholder on the other stakeholders' points of view. In case of relevance, this includes a briefing on the negative effects that the actions preferred by the stakeholder in question actually have on the other stakeholders and the environment (Article 14 of the WFD). Once this information has been shared, the core of this step is the negotiation amongst stakeholders to reach a compromise. The negotiation can be carried out (e.g., with the help of Pareto race, multi-criteria and equity analysis, see Soncini-Sessa, 2005). The result of this step is a set of compromise alternatives that form the programme of measures to be included in the River Basin Management Plan.

2.1.3 Checklist for effective model use

As stated by Loucks & van Beck (2005), the most important aspect of model use today is communication: planners and managers articulate their needs for information. Modellers pick them up and communicate assumptions and results to stakeholders. The next iteration can follow. Water managers and modellers should start cooperating in early stages of the project and, ideally, sustain into the project application phase. Involving stakeholders in model building creates a feeling of co-ownership and leads to a better understanding of everyone’s intentions, concerns, and priorities. The final HarmoniCOP handbook "Learning together to manage together – Improving participation in water management" (see http://www.harmonicop.uos.de/handbook.php) gives practical information about participation processes in river basin management and how to support the implementation of the public participation provisions of the European Water Framework Directive.

Due to the complex nature of management problems in river basins it is impossible to already design the ultimate plan at the beginning of the WFD implementation process. Unforeseen problems are likely to occur and new pressures make it necessary to adjust the programme of measures and to adapt to the emerging pressures and problems. It is therefore crucial that the approach is flexible enough to adapt to new ideas and solutions. A broad participation process including all relevant stakeholders helps identify alternative management measures in order to mitigate problems.

At the stages of identifying and characterizing the individual river basin, including an assessment of the current ecological status, impacts and pressures, preliminary gap analysis, and establishing environmental objectives, modelling may be useful to support the definition of the reference conditions and to assess the possible pressures. An Evaluation of the susceptibility of water status to the pressures can be established by using both monitoring and modelling. Modelling can be useful, because in this initial phase available data are often insufficient (e.g., the data records do not include all the necessary variables, or are incomplete in time and space, or simply erroneous). In combination with monitoring information (both ground-truth and remotely-sensed) and expert judgment, models can help the analysts: (i) assess the impacts of the various pressures, but also (ii) design optimal monitoring networks, and (iii) interpolate the available data. At the stage of designing River Basin Management Plans and programmes of measures, modelling is a useful tool in supporting the assessments and quantification of the effects and costs of various measures under consideration. Furthermore, on-line modelling is often used to support the operational decision making in the stage of implementation of the measures, for example in managing reservoirs (reservoir operation), flood protection and urban drainage systems. Finally, at the stage of evaluating the effects of the planned or implemented measures on the environment, modelling may support the monitoring in order to extract maximum information from the monitoring data, e.g. by indicating errors and inadequacies in the data and by filtering out the effects of climate variability.

The additional value of models lies in them representing the relevant hydrological and ecological processes in a cost-effective way, in due time, and without the need for an “active experiment”. Therefore, models can be used, along with expert judgments and stakeholder dialogues, to characterize water bodies, to evaluate impacts of planned measures in a river basin, to support the implementation of monitoring networks, and more generally for decision support in the planning process as well as in the operational mode.

In order to calibrate models, their parameters should be estimable from readily obtainable data. Operational model use requires data in adequate quantity and quality, and sufficiently good knowledge of the boundary conditions (climate, water and land use management). In practice, this is typically not the case. To overcome the problem of incomplete and inaccurate data, one may try to revise and update the model whenever new data become available. A possible solution in the case of changing and unknown boundary conditions is to integrate and describe possible changes in climate, water and land use management in the form of scenarios, where models since validated can be used to evaluate the possible impacts under scenario conditions on the water quantity and quality. Models can be used to indicate errors and inadequacies in the monitoring network.

From the discussion above it becomes clear that the model setup is often not straightforward, instead it has to be revised and updated in an iterative way. This is theoretically possible in each of the planning and implementation phases of the Directive. To minimize the modelling costs and to avoid the development of models that do not apply to the management problem, involving stakeholders and public participation is absolutely necessary in the initial model setup phase. Another crucial issue is the correct and accurate documentation of each modelling step in a modelling protocol in such a way that the simulation results can be reproduced and retraced. The technically and scientifically adequate execution of all tasks included in a modelling study is called quality assurance, the core of the HarmoniQuA Project of the EU (Scholten et al. 2004).

HarmoniQuA strongly focuses on modelling and quality assurance. It has defined the following five activities for the modelling process:

1. Description of the modelling problem and the development of a model study plan;

2. Compilation of data bases and conceptualisation of the model problem;

3. Setup of a model describing the relevant processes;

4. Calibration and validation of the model;

5. Simulation of the processes and evaluation of the results.

Computer models are in common use nowadays to support planning processes and water resources management. However, as pointed out in Section 1.2, the WFD forms a new challenge for water management and therefore also for hydrological modelling, because the approach of the WFD is to involve all relevant stakeholders on the river basin scale in a common striving to reach the goal of “good chemical/ecological status” of the hydrological system. The challenge is to integrate the interests of all stakeholders (including the environment, e.g., via environmental flows) having sometimes very diverse particular interests, bearing in mind an uncertain future, and considering complex feedbacks in the system structure and changing boundary conditions. Model descriptions may help facilitate this process.

Figure 2.4: WFD’s implementation timetable and the role of modelling structured by the identification phase (blue), the design phase (red), the implementation phase (reen) and the evaluation phase (purple).

Four main management tasks can be identified where models can play a particularly important role to support the implementation process of the WFD, by providing additional information about the chemical and/or ecological status of the specific water bodies and possible impacts of management interventions (Rekolainen et al. 2004, Refsgaard et al. 2005a), which are (see Figure 2.4):

• Identification - assessment of the current status and setup of monitoring programmes (according to the plan – to be finalized by 22 December 2006);
• Design – setup of programmes of measures and River Basin Management Plans (until 22 December 2009);
• Implementation – bringing the programmes of measures into action (until 22 December 2012);
• Evaluation – review of the programmes of measures and improvements achieved (22 December 2015).

Figure 2.4 illustrates the time-frame of the implementation process and the phases where modelling can play an important role.

2.1.4 Iterative process of arriving at the decision

When a compromise alternative can be identified, it means that all the stakeholders are satisfied. Thus the procedure ends and the alternative can be presented to the decision maker(s) as the optimal compromise among all the involved interests and environmental objectives (reply “yes” in Figure 2.3Figure 2.2). In the more common “no compromise” case, the analyst, the stakeholders and the decision maker(s) have to examine whether all possible ways to broaden the consensus have been explored. An iterative application of the planning process should be started in which, depending on the result, different alternatives for proceeding can be considered further.

The following alternatives may primarily be taken into account:

• mitigation of negative impacts by technical measures;
• compensation by external (political or economic) measures (e.g. by subsidies);
• introducing new alternatives in process control (e.g. reservoir building, extending wastewater treatment capacities etc.);
• adaptation through a social learning process with the stakeholders.

The last procedure is very challenging and promising. Fundamentals for this process are being developed within the HarmoniCA and HarmoniCOP projects (see Ridder et al. 2005). They are briefly introduced in Chapter 4.

Mitigation, compensation and proposing new alternatives

If an alternative achieves the consensus of the stakeholder majority, but not all of them, it is important to understand whether measures of mitigation and compensation would further broaden the consensus by satisfying some of the unsatisfied stakeholders. Then it is necessary to identify new kinds of actions to be included in the relevant alternative that specifically act upon the unsatisfied players. A next iteration (from step 2 in Figure 2.2) commences, and it ends when no more mitigation actions to broaden the consensus can be identified. If opponents still exist at this point, the possibility of compensating the disadvantage they perceive must be explored. Here, adaptive management comes into the picture (see Section 4.1).

Political choice and final decision making

Once all the possibilities have been explored and it is clear to the analyst, stakeholders and decision maker(s) that nothing else can be done to broaden the consensus, the procedure is terminated. At that point the set of compromise alternatives includes alternatives supported by the consensus of at least one sector. It is up to the political decision maker to select from this set the alternative of best compromise, i.e., the alternative that accounts best for the different interests and environmental functioning. Technically, the step takes the on form of an evaluation when there is only one decision maker.

The planning of measures

Stakeholders may define as many measures (action alternatives) as they find necessary. With each of them a “planning cycle” may be implemented. The same procedure applied for determining the Baseline Scenario is now repeated, i.e. different measures to overcome the observed gaps and problems are taken as input to the model (or model system) and the resulting effects/impacts (i.e. to simulate the system behavior). Responses capable of avoiding or overcoming the dangerous and undesired pressures on the river basin system are especially sought after.

The suggested framework (Figure 2.2) allows this task to be performed. However, it is recommended to begin with a few, most promising and attractive alternatives, and to present the result of these simulations to the stakeholders for review and discussion. Then they can develop a better understanding of the system and the range of possibilities for an efficient control. This is a first phase of social learning and a good opportunity for searching compromise alternatives.

In the best case, one of the investigated alternatives fulfils the expectations of all stakeholders or comes close to it. In the Spree river basin study for example (Section 2.3.5) the building of a new reservoir was such a solution, fulfilling the requirement of raising water availability to better satisfy water demand (of all stakeholders). Then the evaluation process (step 5) and also the negotiation (step 6) can be completed.

In other cases many more alternatives may be taken into account, for example, (a) other structures (such as levee systems, wastewater treatment plants, or the like, for controlling the processes), or (b) normative or (c) regulatory actions, as in the Verbano case study (Section 6.4). In such cases a set of alternatives is defined for the investigation, and by estimating effects and impacts a multiple “impact matrix” can be established to aid the evaluation (step 5). Optimization techniques and other advanced participation approaches may be included in the evaluation procedure to achieve consensus among the stakeholders in interviews, group discussions, hearings, workshops etc.

In the end, attractive alternatives can be found through negotiation (step 6), from which a set of compromise alternatives may be determined and delivered to the final decision maker (see Verbano case study in Section 6.4).

Iterative planning and conclusions

Whenever consensus cannot be achieved in step 6 (Figure 2.2), a new planning cycle must be started, normally with step 3 where new scenarios and/or alternative measures are designed or a change in paradigm is agreed on.

2.2 1st implementation phase: Assessment of current status, setup of monitoring programmes and evaluation of a Baseline Scenario (gap analysis)

The EU Member States have to undertake several key actions in the first phase of the implementation process of the Water Framework Directive by the end of 2006:

• the assessment of the current status of the water bodies, ready by 22 December 2004;
• the setup of monitoring programmes and implementation and maintenance of monitoring networks, which should be adapted regionally and be operational until 22 December 2006; and
• the evaluation of the water state under business-as-usual management (Baseline Scenario).

These initial works are of crucial importance for the further phases of the implementation as demanded in the WFD: to describe the water management problem (gap analysis), to design programmes of measures, and to evaluate the performance of the measures. Due to the lack of consistent data during the first implementation phase, models and other tools, especially Geographic Information Systems (GIS), in combination with monitoring information help to improve the description of the water bodies, to specify water-related problems and to optimize the monitoring network.

2.2.1 Identification and characterization of water bodies and optimization of the monitoring network

Annex II of the WFD describes a process to identify, categorize and typify water bodies (see also Guidance Document 2 “Identification of Water Bodies”, EC 2003). Type-specific reference conditions have to be identified for each water body type (e.g. lakes, rivers, reservoirs, aquifers). They will be compared with type-specific reference conditions for each water body type to assess the status of a specific water body or group of bodies (guidance on this topic can be found in Guidance Document 6 on “Intercalibration”, EC 2003). “Status classes” of numerical values for the biological quality elements of surface waters in Member State’s assessment systems have to be established, with the ecological status of rivers determined by the lower values (high / good / moderate / poor / bad) from the relevant biological and physico-chemical monitoring results. Groundwater will be classified only as being in either a “good” or “bad” status.

2.2.2 Joint use of monitoring and modellin

Water bodies are complex environmental systems with many unknowns and uncertainties incorporated due to the incomplete knowledge of the processes, to scaling aspects, and to the high spatial and temporal variability of the processes. A comprehensive understanding of the hydrological system, which can be formulated as a site-specific model description of the relevant hydrological processes, in combination with monitoring data, will be of great help in characterizing the water body under investigation and in identifying pressures. It is therefore obvious that the implementation of the European Water Framework Directive creates new challenges on the joint use of monitoring and modelling, and provides excellent opportunities to promote the interaction between monitoring and modelling (Jørgensen et al. 2007).

The models can serve as a tool to analyze, for example, different realizations of an unknown/uncertain hydrological environment (e.g. of the subsurface, Figure 2.5), to identify important flow and transport pathways, sources for contamination (point and diffuse), and impacts of buffers (reservoirs, riverine vegetation) and management measures etc. Based on the modelling information, it is then possible to find monitoring gaps and to improve the monitoring network.

However, due to the complexity of the monitoring/modelling problem, in most cases it is not possible to develop an optimal model or to design an optimal monitoring network. The reason for this is the amount of information and knowledge at hand in the first phase of the implementation process about the relevant processes in the specific river basins. A dynamic approach is therefore proposed (Jørgensen et al. 2007) to overcome this gap during the initial stage of the implementation. Models may indicate errors and inadequacies in the monitoring network. They can also aid in defining the reference conditions, interpolating observations and designing new monitoring networks, or optimizing existing ones in terms of location and number of stations, frequency of measurements, choice of (indicator) parameters etc. (Kampenhorst et al. 2005). The model is revised and updated as new data become available (about the use of models of different complexity and different data demand see Section 3.2.1).

Figure 2.85: Example of joint use of monitoring and modelling: 180 drill log information of the subsurface was used in combination with advanced geo-statistical tools to simulate a set of realizations of the subsurface corresponding to the input information (left: two realizations). Right: by overlaying the realizations, areas with a high reliability of the reconstruction are visible (in red, e.g. the locations of the drill logs), whilst areas with a poor reproduction also appear (blue). The blue areas are the locations where additional monitoring data are needed.

Steps to be taken following Figure 2.2:

Step 1: Problem description: The fundamental first step is to evaluate any existing information about the river basin, including relevant maps, articles and observations. There will be no data arising for the first assessment from the Article 8 monitoring programmes as they do not have to be operational until the end of 2006. These data should be available only later for subsequent assessments for future River Basin Management Plans. However, the countries do not start from scratch; they already have extensive and sometimes long-lasting monitoring programmes in place. These monitoring programmes have to be revised and likely upgraded, and the assessment of the ecological status has to be repeated in an iterative way to accommodate the new information. Problems arise if the data availability is insufficient to identify and characterize the hydrological system under investigation. Here, data assimilation also using expert judgment and modelling approaches in addition to ‘hard’ or traditional monitoring data will be needed to complete the data base.

Figure 2.6: Example of joint use of monitoring and modelling: a statistical methodology was applied for defining an optimal set of sampling intervals (for dissolved oxygen DO) for the operation of a river water quality model. Starting with an extensive set of measurements (left), it is the aim to reduce the number of observations to obtain just as much data as necessary for a calibration with an acceptable uncertainty and thereby to reduce the resulting range of uncertainty (see confidence interval 95 % high – 95 % low) in the parameters (right) (Vandenberghe et al. 2005).

Step 2: Conceptualisation (model setup): Water managers normally have a profound system understanding of the river basin under investigation (in form of a “mental model” resulting from their experience). The task is now to conceptualise the problem identified in the previous step and to set up a site-specific mathematical model of the hydrological system based on the information gained during the evaluation of the observations, whereby the model setup has to focus on the specific management problem. It is recommended to define indicators, such as water levels, water quality characteristics, fish species, and critical thresholds (criteria) of the indicators, to evaluate the state of the system. A modelling protocol should be designed to record the modelling steps (see Section 3.4 and Scholten et al 2004).

Table 3.1 (Section 3.2.1) introduces tools and methods applicable in addition to monitoring data to gain the necessary knowledge about the water bodies under investigation (for a more comprehensive general introduction to modelling and tools see Chapter 3). Evaluation of the data demand in order to operate these tools is included in the table. This is important, because the data availability, which is necessary to use the tools and models, determines their applicability to solve the management problem.

Simple approaches with low data demand, such as GIS-based analytical/statistical methods or simple conceptual models have to be the first choice in river basins where the compilation of the necessary data basis just started or is incomplete. More advanced approaches like physically-based distributed hydrological models integrating different aspects of the water cycle, the environment, and management sectors can be applied where the data support is adequate, or where models have already been applied and adjusted in earlier projects (for questions of model selecting see Section 3.2.1).

The choice of a tool is already very important in this initial stage because model applications in subsequent stages of the implementation of the WFD are likely to build on this first model setup and information gained during the first stage. It is therefore important to consider possible model applications in later stages of the implementation process while conducting the first model setup, compiling the data base and designing the monitoring network.

A good compromise would be to apply, due to the lack of more accurate data, a simplified description of the relevant hydrological processes first, to use it (in combination with monitoring data) to indicate knowledge gaps, and to determine what further investigations should focus on, and based on the first gap analysis to prepare a more complex and physically-based model which can represent, in an adequate way, the relevant hydrological processes. It may well be that the data support is not sufficient enough to fully identify the boundary conditions and parameter structure of a complex model, and the monitoring network has to be improved and designed accordingly.

Scenario definition: During this initial phase of the implementation process, there is no need to formulate a scenario (projection into the future), since the aim of the modelling exercise is to acquire additional knowledge about the current status of the hydrological system under investigation. Therefore, it might be sufficient to run the model in a steady-state mode (under assumption of no changes of the boundary conditions during the simulation process).

Simulation / estimation of impacts: The site-specific model should be applied with due consideration of the different possible descriptions of the basin environment and climate / management boundary conditions in order to check the agreement of modelling results with the observations and to identify knowledge gaps.

Evaluation of the results: The last step in the process is the evaluation of the results. The advantage of starting with a simple model description of the hydrological system (like a combination of GIS, statistical analysis and conceptual equations), is that they are easy to apply and give first (rough) results quickly and in a cost-effective way. For example, information on the long-term water and nutrient balance of the entire river basin can be obtained, although the spatial and temporal aggregation of the information will be high. Therefore, evaluating the results has to take into account that the uncertainty of the outcome of simple models is usually high (see Section 3.3). However, the achievable accuracy can be sufficient to characterize water bodies which are not in danger of failing to meet the WFD objective of reaching a “good chemical/ecological status”. Otherwise, in a second iteration, the work can focus on the areas of the basin where the water management problems could not be solved applying the simple model setup, with the help of a more complex and physically-based description of the hydrological system.

2.2.3 Identification of pressures and formulation of a Baseline Scenario

The next step recommended by the WFD is to collect and maintain databases containing information on the type and magnitude of the significant anthropogenic pressures the surface water bodies in each river basin district are subject to (Article 5 of the Directive). An assessment must be made of the vulnerability of the water bodies to the pressures identified and how likely water bodies within the river basin district will fail to meet the environmental quality objectives set under Article 4 of the WFD. This assessment will use any available data, while the extent of existing monitoring data will again vary greatly from country to country and also from river basin to river basin. Additional modelling information will be necessary (Figure 2.7) especially for the formulation of the Baseline Scenario.

Figure 2.117: Identification of pressures –the observed and simulated groundwater levels are shown (Hattermann et al. 2005).
(a) The observed trend in groundwater levels starting from summer 1983 cannot be reproduced taking only observed climate variability as driver.
(b) The groundwater hydrographs agree when the simulation is done assuming a management induced decline in the drainage basis of -0.35 m in the period 1983 - 1984 (d1) and of -0.80 m in the period 1990-1991 (d2).

Steps to be followed following Figure 2.2:

Problem description and goal definition: The conceptual problem is that solely applying monitoring information to identify the pressures on the system might not be sufficient. This is because the WFD explicitly demands to also include already planned management measures in the evaluation of the pressures (for example measures necessary due to national programmes or to implementation plans of the EU Urban Wastewater Directive etc.). These new measures might change the state of the hydrological system and result in additional pressures (see case study of the Marne Pilot River Basin and Seine-Normandie District in Section 6.2). One important method, besides data evaluation, that aids analysts in identify these pressures on the hydrological system is the formulation of a Baseline Scenario the anticipated “good status” (Article 4 of the Directive) can be compared to and any gaps in reaching it can be determined. Based on the understanding of these gaps, the programme of measures can then be planned according to the WFD to reach the “good status”.

A model description of the hydrological system taking additional management options into account, would be an option for analyzing the development of the hydrological system under investigation and for evaluating impacts of new management alternatives.

Conceptualisation (model setup): The model description of the Baseline Scenario has to build on the work which has been done to characterize the state of the hydrological system under investigation. Like in the previous step, it is recommended to consider data demand vs. data availability when selecting models to describe and evaluate the hydrological environment. While the modelling to support the characterization of individual water bodies can often focus on one component of the hydrological system (like groundwater), the modelling challenge to evaluate a Baseline Scenario is normally higher. This is so, because many different hydrological processes interact in a river basin, management has to be considered, and the approach has to be dynamical and unsteady-state (i.e., the boundary conditions may change during the modelling period, for example because of the new management measures).

Possible indicators to evaluate the state of the river basin are water levels and nutrient concentrations in groundwater, rivers and lakes. More challenging are ecological indicators (fish species, algae composition) and river morphology. The site-specific model has to prove that it is able to reproduce the relevant hydrological processes (calibration), also under changing boundary conditions (validation (see Section 3.2.4). The model setup and validation process should be recorded in a modelling protocol (see Section 3.4 and Scholten et al. 2005) to guarantee transparency in the modelling process.

It is strongly recommended to guarantee maintenance of the site-specific model setup, because it is very likely that modelling will also be needed to support the further steps of the implementation process, as listed below. Model maintenance will also enhance transparency, because it may be necessary to repeat the modelling exercise in order to investigate potential problems with the modelling results, or to include new management strategies.

Scenario definition: The Baseline Scenario is a business-as-usual scenario including already planned and formally agreed-on new management measures. External drivers may be population growth, globalization (socio-economic change), climate change etc. The optimal situation would be predictions being available. Otherwise, assumptions must be made on future developments (e.g. trend extrapolations) with stakeholders and experts participating (see Marne case study in Section 6.2). Another option here is to use stochastic models for time series generation into the future. For instance, one can generate precipitation by a method which represents a mixture of objective simulation techniques and stakeholder advice (see Spree river basin case study, Section 6.6).

Simulation / estimation of impacts: The simulation should be done first without representing the planned management measures in the model framework, and afterwards including them, to evaluate the impacts of the new measurements and the sensitivity of the hydrological system to the anticipated changes. Like in any modelling exercise, it is important to analyse the robustness of the simulation results as well or, in other words, the reliability / uncertainty of the results (see Section 3.4).

Evaluation of the results and alternatives: The evaluation of the long-term impact of the business-as-usual scenario on the ecological status of the river basin will be the key information to identify obstacles in reaching the objectives of the WFD. There cannot be a real negotiation of the alternatives here, since there is consensus on the new management measures, They will be taken into account according to the Baseline Scenario (by definition of the Baseline Scenario, they are already in construction or at least planned). Nevertheless, evaluating their impacts will give additional information about possible management options for the future, and the setup of the programme of measures will have to build on the results gained during the evaluation of the Baseline Scenario.

2.2.4 Example 1: Marne/Seine/Normandie – modelling and the Baseline Scenario

(For the full description of the case study see Section 6.2)

The basin characterisation according to Article 5 of the WFD intends to provide input to the decision-making process and the public participation from 2005 to 2009. This is a prepares a programme of measures that should be started by 2009 and aims at achieving the overall WFD objectives by 2015. Then integrating the current dynamics of the water status and policy appears necessary. Therefore, it is important to anticipate results from the implementation of existing European water directives before they have been completed. Some progress is expected in the near future (e.g. from “terminating” the implementation of the Urban Wastewater Directive and of the Nitrogen Directive), while at the same time some environmental factors may worsen (e.g. related to pesticides). Hence evaluating the business-as-usual (BAU) trends is unavoidable in deriving a Baseline Scenario (BLS).

Step 1 - Problem description and definition of the environmental objectives

The general methodology that was used for designing the modelling tools was indeed strongly dependent on the precise goals derived from the WFD context. The final goal is to reach the “good ecological status” in all water bodies until 2015. In order to reach this goal the following questions need to be answered:

Step 2 – Conceptualisation Based on this goal definition, the model-supported planning system can be described as follows, starting from the anticipated “end-results” and going up to the institutional and legal analysis. See the figure to the left for a schematic organisation of the system. Figure 2.8: Structure of the model-supported management planning in the Seine-Normandie basin.

This drivers-pressures model is linked to ecological quality models (see Figure 2.13Figure 2.8) by simulated GIS-localised net pressures. The modelling methodology used for the drivers-pressures model does not demand a specific technology. It is based on linear programming with current office software (such as Access).

The modelling methodology used for the status simulation tools is by far more complex. Although their basic “engine” stems classical ecological equations, they are developed through specific applications for the Seine basin, linking GIS with calculation engines.

Step 3 - Definition of scenarios

External drivers Context scenarios were built by referring to existing sector analyses, EU and national agricultural projections, national interpolated demographic data, etc. Adaptations of large-scale scenarios to the basin or to specific sectors, when needed, were based on expert forums and stakeholder knowledge.

Internal drivers In Baseline Scenario, internal drivers comprise the technical translation of the business-as-usual water policy into an “equipment programme” of implementing existing water-related directives and national provisions and orientations.

Step 4 and 5 – Analysis of effects and evaluation

The quantification of effects and impacts of scenarios relates to 2 linked important outputs:

• The evolution of pressures, impacts on rivers, and the corresponding ecological status.
• The assessment of economic cost of the equipment programme, and how it relates to the current expenses.

Figure 2.149: Risk assessment (likelihood of failing to reach the “good status”) map for Seine-Normandie.

The evaluation deals with policy-relevant issues of the Baseline Scenario results. Results are meaningful with respect to general assessment of the likelihood of failing to reach a good ecological status in Seine-Normandie water bodies and the cost of business-as-usual policy, comparing to current expenses, and evaluating of required changes in investment rates and volumes (see Figure 2.14Figure 2.9).

2.3 2nd implementation phase: Support for design and setup of programmes of measures and of the River Basin Management Plan

2.3.1 The River Basin Management Plan

Perhaps the most important and central implementation task according to the WFD is the establishment of programmes of measures (WFD Article 11) to produce and publish River Basin Management Plans (RBMPs) for each River Basin District (RBD), including the designation of heavily modified water bodies, by 22 December 2009 (Article 13, Article 4.3) . The RBMP serves as the main reporting mechanism for river basin district authorities to the EC and summarizes the results of the two first implementation phases. The functions of the plan are (after GD 11, cf. EC 2003):

Item (1) of the RBMP, the inventory and documentation of the water bodies, of the environmental objectives and of human impacts, was the main task during the first implementation phase and should be finished by December 2006. The main task for the second implementation phase is to set up programmes of measures describing how to reach the environmental objectives identified in the intercalibration process of the first phase. For each river basin district, the programmes of measures to be established by the end of 2009 are to describe the regulatory provisions or basic measures to be implemented in order to achieve the objectives of what the management plan defines for 2015. This includes taking pricing measures to provide users with incentives to manage water more efficiently. Measures may be decided on a national level in accordance with community and/or national laws (e.g. indicating responsible authorities, a reporting system, and defining protected areas, discharge control etc.).

2.3.2 Planning for an uncertain future – scenario definition and model support

The basic problem in designing the River Basin Management Plan lies in making it for an unknown or at least uncertain future and at the same time integrating water availability, quality and demand in a cost-effective way. The plan must take into account the development and variability (seasonal and inter-annual) of water availability, quality and demand. Meanwhile water quality is often strongly dependent on water quantity, i.e. stream flow and/or water volume (storage). This problem is illustrated in Figure 2.10.

The left side in the figure represents the past, which is known and can be evaluated on the basis of available monitoring and observation data. The future, on the right side, is unknown or uncertain, at least. As far as water availability is concerned, it is unknown whether and when a drought, or a sequence of dry years (with prolonged droughts), or an extreme flood period are to be expected. This is the case although the information on future vulnerability has to be considered in the programme of measures in order to avoid undesired impacts for the public under such conditions.

Figure 2.10: Typical situation in a planning study (Kaden et al. 2002).

Concerning water quality, the future is more certain since water quality can be influenced by local water and land use management, even though political decision making has its own level of uncertainty. Projections into the future are required, in the form of scenarios (possibly assumptions) related to future weather conditions (climate) and other external driving forces over the planning period of, for example, 20 years, calling for taking climate change and socio-economic growth into account. The scenario technique is an appropriate tool here. The scenarios should be internally consistent and plausible alternative projections into the future (rather than being misleadingly promoted as accurate and reliable predictions).<:p>

In summary, information on land use change and related scenarios of climate change is required in the form of:

(a) projections of the driving forces (especially external drivers) into the future (over the planning horizon of e.g. 20 to 50 years). These driving forces can be climate change or variability and socio-economy (agriculture, industrial development);

(b) a design of the measures that will definitely occurring (e.g. basic measures), and have already been planned or confirmed for implementation (the same as for the Baseline Scenario), and additional measures potentially leading to an improvement of the water status.

Figure 2.11: Example of a comprehensive model system to investigate land use and climate scenario impacts on water resources (example taken from the GLOWA-Elbe project, see Wechsung et al. 2005).

Figure 2.11 illustrates information flow (model system) investigating consistent land use and climate change scenario impacts on water availability and water quality. A similar information flow and model setup can be applied for investigating water demand (water management), susceptible to change due to technology changes or economic development, or in dependence on weather conditions. Considering global (external) drivers must be considered, since they cannot be influenced locally but can have a significant impact on the hydrological system (water quantity and quality). Regionalization of the global changes is important, Future data may not exist, especially for socio-economic boundary conditions, so expert knowledge has to be put to use.

During the scenario setup it is to describe water availability and quality under normal (average) conditions as well as under extreme conditions (low flows and droughts in summer and other seasons, but also high flow conditions and floods). In extreme conditions there may be too little water to fulfill water needs and to dilute pollution, or too much water, so that the capacity of sewage systems is exceeded. Often one must take the real sequence of the varying hydrological conditions and events into account reaching from normal” (average) years and seasons to wet and dry conditions, including extreme events (floods and droughts). A continuous simulation in the future (monthly or even daily) by using Monte Carlo techniques may be required for a longer future periods (for example 20 or 50 years).

Here a fundamental decision must be taken by the responsible modelling group (in agreement with decision makers and stakeholders): Should a stochastic generation technique be applied to generate long time series of water availability in terms of river flow (discharge), water quality, or precipitation? And what is the adequate time step in the time series generation (a month, ten days, a day)? Time series generation is the only appropriate solution in river basins with existing reservoirs, since intra- and inter-annual water storage plays an important role for demand periods. This case is discussed in the Spree river basin case study (see Section 6.6). Only such a technique makes it is possible to link wet / water surplus periods (seasons or years), where water can be stored with dry seasons and years, where stream flow becomes small or may even disappear, as for example in many ephemeral Mediterranean rivers. Similar conditions may also occur in other zones and environments, including the continental climate zone in Eastern Europe and in the Eastern part of Central Europe. It is advisable to try to compensate the deficits by water stored during the surplus periods, for example in winter or in flood seasons.

Similar statements can be made on water quality as it directly depends on water quantity. Planning under such conditions is a rather difficult and challenging task. The stochastic character and variability of hydrological processes must be considered. as do long time series of river flow, or any other variable of interest in the planning process, and exceedance probabilities.

Simpler cases may exist with planning done with defined reference values, for example with long-term average flow or any extreme flow. In turn, simplifying assumptions can be accepted in the planning process. However, in the more complex cases, as mentioned before, the troublesome efforts are required, some of which are explained in the case studies.

2.3.3 Model-supported design of the programme of measures

Models will certainly play a key role in facilitating the selection of measures to achieve the environmental objectives according to the WFD, and to develop the River Basin Management Plan. The reasons for this that planning has to advance several projections into future development of external drivers and management options. An appropriate model description of relevant processes in a river basin allows for assessing the impact of many combinations of the external drivers and different management strategies and facilitates decision making by eliminating unfavourable solutions,.

Steps to be done following Figure 2.2:

Step 1 - Problem description: The problems can be defined on the basis of experiences in the first implementation phase, the characterization of the water bodies, and the preliminary gap identification according to Article 5 of the Directive (see Baseline Scenario). The questions to be answered in this phase are:

• which management alternatives are appropriate to achieve the environmental objectives, and
• which of them have the highest cost-effectiveness and are supported by the pertaining stakeholders.

It is absolutely necessary to establish a good communication platform of water experts, stakeholders and modellers for broadly discussing the problem definition and goal identification from the start. Later on, these discussions help to set up a site-specific model addressing water related problems. They also aid in increasing the acceptance and understanding model results.

Step 2 – Conceptualisation and model setup: The model setup for supporting the design of the programme of measures is usually the most advanced component of the planning process, because it has to integrate many different hydrological variables interacting in the river basin, and it has to consider different management options. The approach has to be dynamic and unsteady-state, i.e. for covering changing boundary conditions during the modelling period to correspond with the designated management measures. The challenge in the river basin model lies in reproducing a variety of different possible management options (boundary conditions) and their impacts, unlike in the model setup for the Baseline Scenario. For that purpose, the boundaries of the hydrological system and the time and space domains must be defined carefully. The responsible authorities, stakeholders, and sectors involved should be determined (institutional and stakeholder analysis). Furthermore, the institutional and legal framework of the plan should be defined and considered in the model setup.

Following the DPSIR (Drivers, Pressures, State, Impacts, Responses) scheme, the relevant Drivers, Pressures, and State of the hydrological system, Impacts and possible Responses have to be defined. Identifying potential management options is primarily expert- and manager-based and is intellectual work. The final concept should be discussed with stakeholders and experts either individually or in group discussions to receive their approval, advice and comments. Therefore all activities that may raise consensus must be promoted in this step.

The potential management alternatives, environmental objectives and related indicators determine the tools and model setup for investigating pressures on the state of the system and for evaluating their impacts. The case studies Witte, Nete, and Dender in the Scheldt Pilot River Basin, and Verbano summarized at the end of this chapter give an insight into how the goal definition and stakeholder identification was performed in two example river basins.

Characterizing of the water bodies including preliminary gap identification was the goal of the previous implementation phase finalized by 2005. It can be of use here. The Site-specific model setup for the Baseline Scenario is further useful work from the previous phase. It can be applied and improved in this one to estimate the ecological status of the river basin while considering additional management interventions. The model setup benefits if the data needed for modelling was considered while the monitoring network was implemented according to Article 8 of the WFD. It should build on the existing modelling activities undertaken during the identification of the river basin districts and the investigation of the Baseline Scenario.

However, if no model description of the river basin exists, starting off by setting up a simple, e.g. GIS-based model description of the hydrological system is recommended. Similar to the investigation of the Baseline Scenario, the simple model setup may already suffice to compare different management options with adequate accuracy and credibility and to design the programme of measures. If not, an evaluation of the existing data bases compiled during the first phase of implementation until the end of 2006 is recommeded in order to assess the data support for a more complex site-specific model setup.

Step 3 - Scenario definition: Scenario definition plays a key role in designing the programme of management measures for meeting the environmental objectives that are pivotal to the RBMP. The scenarios determine the boundary conditions water management in a certain river basin will be based in future (see Section 2.3.2). Part of the scenario(s), especially the external drivers, will have to be chosen by experts or obtained by running models that describe the relevant processes producing the driving forces; e.g. the future scenario of rainfall. However, the WFD explicitly requests the involvement of the public in the planning process. The development of different water management scenarios offers an excellent opportunity to discuss and integrate different visions (alternatives) of future water and land use management in a given river basin by consulting va