Raising the voice of science in complex socio-political contexts: an assessment of contested water decisions

Agencies are increasingly developing evidence-based policies to manage natural resources. However, the influence of science in policy is not straightforward nor guaranteed. Critiques based on literature meta-analyses or policy-maker interviews suggest deficiencies in science production and delivery with some studies highlighting the importance of human dimensions. In interviews with decision-makers in freshwater policy in New Zealand and California, we investigated barriers to using science in complex and contested policy contexts. Findings highlighted the importance of the science, scientist, decision-maker, and the decision maker's relationship with the scientist, for improving the influence of science on policy decisions. The influence depended more on the scientist delivering the information and the audience receiving it, than on the nature of the science itself. Frameworks like CRELE (credibility, relevance, legitimacy) and ACTA (applicability, comprehensiveness, timing, accessibility) are essential but outweighed by the human dimensions of policy development. With greater public, industry and NGO oversight of policy debates related to highly contested resources like water, the volume and quality of science for policy has greatly improved, meaning CRELE and ACTA factors have less prevalence. We give three categories of recommendations for improving the use of science in decision-making - science communication, science production and policy processes.