Table 2 Identified forms of effectiveness, their measurement and relevance to NFM

Procedural

Adherence to standardised processes and best practices

NFM is argued to work best if governance frameworks are attuned to collaboration between diverse actors and knowledges

Development of NFM should be context-sensitive—should not take a ‘cookie cutter’ approach

Decision-making processes need to be altered so that FRM is addressed at a catchment system level

NFM processes should take account of contextually relevant best practices

Substantive

Achievement of stated goal

NFM should contribute to the reduction of flood risk and this should be measurable

Transactive

Time and costs associated with the activity

The time and costs associated with NFM implementation (and maintenance where relevant) need to be made clear to enable cross-comparison

NFM can potentially serve to reduce longer-term costs associated with climate change, particularly if urban development patterns are more sensitive to water as a result, but these savings must be calculated in a way that recognises inherent uncertainties with this type of projection

Normative

Contribution to broader ideals

NFM—if performed well—can contribute to broader ideals such as climate change mitigation, sustainability, health & wellbeing, and socio-ecological resilience, as well as increasing local cultural value and biodiversity

Within this review we focus specifically on the normative benefits of NFM that relate to climate change mitigation and adaptation