Exploring International Freshwater Ecosystem Management Strategies for New Perspectives: the Noce River, Italy and Yuba River, California, USA

We compared freshwater ecosystem management of the Yuba River, in California, USA, and the Noce River in the Province of Trento, Italy to examine how cultural and political practices can shape freshwater ecosystem management strategies within similar geographical and hydrologic contexts. Specifically, we compared climate, land-use history, flow regulation, restoration approaches, and associated challenges and successes. The Yuba and Noce catchments both have Mediterranean climates, runoff sourced by rainfall and glacial or snowmelt, and developed water supply resources for agriculture, municipal water supply, recreation, and power generation. Both rivers have long histories of human modification, including damming in the 20th century to accommodate escalating energy demand and intensive agriculture. Dam releases for power generation on the Noce River result in hydropeaking, altering the eco-morphodynamics and limiting biodiversity. Water supply storage, diversion for agricultural use, and gravel extraction on the Yuba River results in highly altered flow regimes and degraded instream habitat. Contrasts between the rivers’ respective regulatory frameworks and their intended goals yield different management actions. In the Yuba, the US Endangered Species Act drives targeted restoration for species-specific recovery, limiting broader holistic protections for the aquatic ecosystem. Whereas in the Noce, the European Union Water Framework Directive mandates broad ecosystem benchmarks be met, with restoration focused on improving habitat, biodiversity, and water quality. However, the top-down approach may limit stakeholder involvement. Recently, success in coalition building among California water managers, academic institutions, conservation groups, and private landowners has led to reconnecting floodplain habitats and providing environmental flows for native salmonids. Implementing alternative hydropower generation schemes in the Noce has led to improved aquatic biodiversity metrics and increased recreation opportunities. As climate change exacerbates impacted river functions worldwide, comparison of freshwater ecosystem management between international catchments offers potential new solutions for sustaining essential ecosystem services.