To plan in the face of the unknown: Dealing with uncertainties in Strategic Environmental Assessment

Abstract

Goal Uncertainties pose a challenge for the Strategic Environmental Assessment (SEA) of spatial plans. This is because political decisions are based on the outcomes of the assessment, with possible negative consequences for the environment and public health if predictions are inaccurate. This thesis examines how uncertainties can be successfully addressed, by creating and testing a conceptual framework for uncertainties and management strategies, their linkages and factors contributing to a successful application of strategies. Research methods A qualitative approach is used provide a deeper understanding of (the management of) uncertainties in SEA. A general theoretical framework is created by using literature on SEA, uncertainties in environmental research and possible strategies to address uncertainties. The framework is tested in five case studies of spatial planning projects in the Netherlands. Semi-structured interviews are conducted with practitioners involved in the SEA process. An additional document analysis supports the findings of the interviews. Findings A wide variety of uncertainties is identified, categorized into inherent, scientific, social and legal uncertainties. Most of these results are confirmed in the case studies, except for uncertainty in project organization. Uncertainty in the quality of methods is identified as a new type of uncertainty. Combinations of strategies are found to be successful. Especially addressing uncertainty in values and perceptions of stakeholders, where combining negotiations, customized norms and regulations and a monitoring program, ensure a sense of security for stakeholders and support for the spatial plan. It was not expected that social uncertainties would be addressed with other strategies than stakeholder involvement. As strategies are often aimed at providing just enough information, the success of strategies is mostly determined by the level of decision-making and the level of (legal) risk. Recommendations Uncertainties can be successfully addressed if environmental limits, that result from either a worst-case scenario, stakeholder negotiations or additional research, are explicitly included in a monitoring program. This ensures a sense of security and a control mechanism for after decision-making. Recommendations to achieve this are to integrate SEA and the spatial planning process, provide guidelines for standardized tools, give a large role for experts of the NCEA during the process and after decision-making and push for a pro-active approach towards uncertainties. Lessons for future spatial development projects in the Dutch Omgevingswet are that similar uncertainties still exist, yet require a different approach: it is infeasible to assess alternatives and worst-case scenarios, and more successful to assess the carrying capacity, thresholds and a monitoring program.