Challenges in developing an integrated catchment management model David N. Lerner, Vikas Kumar, Annelie Holzk¨ amper à , Benjamin W. J. Surridge w & Bob Harris Catchment Science Centre, Kroto Research Institute, University of Sheffield, Sheffield, UK Keywords Bayesian network; integrated catchment management; participatory modelling; Water Framework Directive. Correspondence David N. Lerner, Catchment Science Centre, Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, S3 7HQ Sheffield, UK. Email: d.n.lerner@shef.ac.uk à Present address: Agroscope Reckenholz- T¨ anikon (ART), Zurich, Switzerland. w Present address: Lancaster Environment Centre, Lancaster University, UK. doi:10.1111/j.1747-6593.2010.00229.x Abstract Directives and policies increasingly call for more integrated management of land and water. Frameworks such as integrated catchment management may address these calls, and yet their implementation requires decisions to be taken under conditions of extreme complexity and uncertainty. This paper sum- marises a participatory framework through which decision-makers, experts and system modellers can collaboratively develop an integrated model to support such decisions. A feasibility study showed the potential of the frame- work. An operational version of the model, able to analyse the effects of 50 management options on 20 indicators, is estimated to require in the order of 225 man-months from system modellers, alongside substantial inputs from stakeholders. The significant technical challenges confronting such an exercise may be overshadowed by the institutional challenges, including the funda- mental question of whether organisations are truly committed. However, the reward for overcoming such challenges is the opportunity to achieve genuine improvements in the social, economic and environmental quality of our catchments. Introduction Managing water and land as an integrated whole is a major challenge for the 21st century and beyond. The UN’s Millennium Development Goals, and various in- ternational and national environmental directives and policies, all highlight the pressing need for more inte- grated approaches to environmental management. Var- ious frameworks for integrated management of land and water have been proposed, for example, integrated water resource management and integrated catchment management (ICM). These are based on a holistic approach to interconnected environmental issues, con- sidering the objectives and responsibilities of multiple stakeholders. They promote consideration of the con- flicts and synergies between different management options, objectives and stakeholder interests, and seek remediation of existing issues alongside consideration of possible future pressures and impacts (Fig. 1). In Eur- ope, ICM is the philosophy underlying the Water Framework Directive, which requires River Basin Management Plans to be prepared and acted upon in 6- year cycles up to 2027. However, implementing ICM means dealing with highly complex and uncertain decision-making contexts. There are multiple stakeholders with potential interests in ICM, from government agencies to local pressure groups. These stakeholders hold often competing perspectives on the challenges that ICM should be addressing and on the range of possible solutions to these challenges. Although frameworks such as ICM are often promoted as science- or evidence-based, our understanding of many compo- nents of the environmental and social systems involved is often incomplete or entirely lacking. Frameworks such as ICM also challenge historical approaches to land and water management that have been dominated by single- issue solutions and had little engagement with broader groups of stakeholders. For these and other reasons, implementation of ICM has often fallen short of the ideals described above. One potentially important route forward to address this implementation gap is the development of tools that enable decision-makers to think in different ways and, ultimately, to come to more integrated decisions (Argent 2004; Reichert et al. 2007). These decision-support tools can underpin communication and learning within a decision-making group, for example, by providing the best available evidence base for comparing the impacts of different management options on multiple objectives and Water and Environment Journal 25 (2011) 345–354 c  2010 The Authors. Water and Environment Journal c  2010 CIWEM. 345 Water and Environment Journal. Print ISSN 1747-6585 Promoting Sustainable Solutions Water and Environment Journal