When the water runs dry: supporting adaptive governance in transboundary river basins

Abstract

Impacts of global climate change will primarily be felt through the water cycle. Adaptation to changing conditions in transboundary basins is an important precondition to ensure regional sustainable development and political stability. However, adaptation measures in one basin country can affect water resources and adaptation options elsewhere, therefore often requiring coordinated or joint responses by riparian countries. The paper examines the potential of climate policy instruments in strengthening adaptation to changes in transboundary river basins in North America's Colorado River Basin and Southern Africa's Orange-Senqu River Basin. It finds that climate policy instruments are yet rarely employed to jointly manage adaptation in shared rivers but nonetheless harbour great potential.

What will it take to stabilize the Colorado River?

“…Since 2000, the average annual natural flows (that which would exist without human interventions) into Lakes Powell and Mead have been almost 20% below the 20 th Century average (1,2). As a result of these unprecedented low flows and insufficient management adaptations (3,4), five-year projections by the Bureau of Reclamation (Reclamation) suggest that Lake Powell, created by Glen Canyon Dam, has a one in four chance of falling below the minimum elevation necessary to produce hydropower. Storage downstream in Lake Mead, created by Hoover Dam, has a two in five chance of falling to its most severe management condition which forces large reductions on downstream users (5).…”

Governança dos recursos hídricos na Bacia Hidrográfica do Rio Salitre-BA: análise sob a perspectiva do ciclo adaptativo

“…Os mecanismos de governança adaptativa em sistemas auto-organizados são diversos, podendo ser verificados através de iniciativas comunitárias e cogestão colaborativa (Olsson et al, 2004). Os dispositivos legais e o arcabouço institucional também têm grande impacto na existência ou não de uma governança com caráter adaptativo (Silva & Ribeiro, 2021;Blumstein & Petersen-Perlman, 2021;Trimble et al, 2022). Tais mecanismos, em sua maior parte, são de natureza colaborativa e formada em nível local, respondendo à escala de um problema específico.…”

Irrigation response to drought in the Western United States, 1987–2021

“…Changes in irrigation water use can have a subannual, bidirectional impact on streamflow, and increases in irrigation water use may exacerbate climate-driven streamflow changes, especially in the Colorado River basin (Essaid & Caldwell, 2017;Ficklin et al, 2013;Ketchum et al, 2023). The ongoing water supply crisis in the U.S. Southwest has led to calls for alternative, adaptive management (Blumstein & Petersen-Perlman, 2021) and a recognition that simply improving on-farm water efficiency through infrastructure modernization might have the unintended consequence of increasing basin-scale water use (i.e., the "paradox of irrigation efficiency"; Grafton et al, 2018;Scott et al, 2014;Wheeler et al, 2021Wheeler et al, , 2022. While humans have control over water use in the river systems in the region and could thus expect management actions to impact future water supply, creative and cooperative management is impossible without first characterizing the behavior of irrigation, the largest consumptive use by society.…”