Sociotechnical Transitions in Water Systems: Applying the Multi-Level Perspective to Characterize the Transition from Centralized to Dual System Water Supply

Centralized urban water supply systems affect high social, economic, and environmental costs through large-scale treatment and distribution of potable water for all end uses. This technological regime is being challenged by climate change, population growth, and aging infrastructure. One sustainable practice is the reuse of wastewater for non-potable end uses through a dual water reticulation system. There are few large-scale implementations of dual systems in the US, and proactive adoption of dual systems is rare. This is because water infrastructure, as a sociotechnical system, exists in a three-dimensional landscape of technology, society, and institutions. The transition from a centralized water management paradigm to a decentralized, fit-for-purpose regime is a major transformation which involves not only technological changes, but also changes in the momentum of behaviors, regulations, infrastructure, and symbolic meaning. This research applies the multi-level perspective (MLP), which is a leading theory in the field of sustainable transitions, to characterize the transition from a centralized water system to a dual water system. The MLP is applied to characterize landscape pressures by calculating changes in four standardized exposure metrics: water stress, public attention to water supply issues, financial stress, and policy developments. Time series of the four exposure metrics are synthesized to explore periods of accelerated change (PoACs) when data show increasing public attention, higher water stress, and multiple new water-related policies. In 2001, the Town of Cary became the first water utility in North Carolina to utilize a secondary water reticulation network for providing reclaimed water to households and businesses. This research applies the MLP to characterize landscape pressures in the context of water stress and public attention to the Town of Cary dual system. The MLP provides a description and explanation of the effects of landscape changes on consumer support for reclaimed water reuse.