Analyses of costs and benefits require the prediction of the effects of restoration measures and the quantification of societal values. Both of these estimates are uncertain. In this report, some of the key issues related to the assessment, description and quantification of uncertainty are discussed and guidelines are provided for considering uncertainty. 

This report provides a brief overview on the representation and quantification of uncertainty in scientific prediction followed by examples of typical risks associated with river restoration that could lead to unintended, adverse effects and in more detail, how uncertainty can be considered in CEA/CBA and in MCDA.

Rivers are highly complex ecosystems with interrelated processes between physical, chemical and biological components. River restoration efforts are put in place to overcome pressures from the development sector to improve river process and function, nevertheless, river restoration tends to encounter obstacles as a result of these societal demands. To stop restoration projects falling short of their objectives, there is a need to demonstrate and predict the effects of human activities on these components spatially and temporally.

The overall aim of this document is to provide guidance and tools for river managers to analyse the potential effects of degradation, restoration, climate and land use change to optimise benefits between cross-sectoral river services and ecological requirements whilst considering climate change effects. Failure to plan across the full array of ecological and socioeconomic co-benefits can have undesirable and unanticipated consequences.

The report provides an overview of existing guidelines and manuals related to the assessment of costs and benefits of river restoration. Although there exist many cost-benefit analysis handbooks, there are not many related specifically to river restoration. This report aims to fill this gap, and focuses on the specific characteristics of the estimation of costs and benefits related to river restoration. The report discusses the classification and assessment of costs and benefits of river restoration, and develops a benefits transfer approach that can be used to assess benefits when it is not possible to carry out primary valuation research. Key methodological issues in a CBA of river restoration are identified, discussed and illustrated. The report provides a number of practical recommendations to practitioners.

With an increasing emphasis on river restoration comes a need for new techniques and guidance. Despite the rapid increase in river restoration projects, little is known about the effectiveness of these restoration efforts. Restoration outcomes are often not fully evaluated in terms of success or reasons for success or failure. This report strived to meet this need by developing a protocol for benchmarking and setting specific and measurable targets for restoration and mitigation.