Paper long abstract:

Research and policy frameworks have been elaborating the energy-water-food nexus to identify potential synergies across those three components. The nexus concept is meant to inform eco-innovation design and adoption, towards investment enhancing resource efficiency. By going further, the concept can also enrich socio-technical perspectives on decision-making processes for sustainability transitions (Grin, 2010).

Such perspectives inform the FP7 EcoWater project, which develops and applies whole-system eco-efficiency indicators in diverse water-service systems. The project has several aims - to compare the overall eco-efficiency of the baseline situation with improvement options, to identify their drivers & barriers, and thus to facilitate better decisions by investors and policymakers. Multi-stakeholder workshops discussed investment options.

Preliminary results: For future investment decisions, a key factor has been energy costs in various senses. Energy costs could be lowered by some options, e.g. by reducing the burdens of water abstraction or wastewater treatment. But energy costs could rise in other options - e.g. by removing hazardous micropollutants from urban water systems, by targeting irrigation water more efficiently on crops, and by minimising (or removing) excess heat from cooling water.

More fundamental socio-technical dynamics reveal asymmetrical incentives. Most investment options lie within current production-consumption patterns, whereby incremental eco-innovation offers only modest improvements (or even a potential rebound effect) in resource burdens. By contrast, major systemic changes (e.g. a shift to organic agriculture or district heating) would offer greater societal benefits - but lie beyond current institutional incentives and responsibilities.