A recent study has found that Colorado’s West Slope water basins may be reaching a critical tipping point where maintaining traditional water delivery levels to Lake Powell and other crucial areas could become unsustainable, even under modest climate change scenarios. The research, published in Earth’s Future, focused on six watersheds within the Colorado River Basin on the western side of the continental divide. These watersheds feed into Lake Powell and support a $5 billion annual agricultural economy, making them essential water sources for seven western U.S. states, as well as Mexico. The study’s findings suggest that even moderate climate change and streamflow declines in these basins could threaten to breach a tipping point where the system may no longer sustain current delivery levels to Lake Powell.
To conduct the study, the research team combined Colorado’s StateMod water planning model with a new modeling framework to generate hundreds of thousands of streamflow scenarios under historical and climate-change conditions. The results indicated that traditional drought vulnerability analyses, based solely on historical streamflow records, may underestimate the potential impacts of drought events on water storage, agriculture, and municipal water supply. This information is crucial as state and federal policymakers are set to negotiate water-sharing agreements that are soon expiring. The study also highlights the importance of advanced drought analysis methods that can capture the widespread and interconnected impacts of climate change and natural variability on water resources in the region.
The timing of this research is significant as it builds on recent events, such as the unprecedented 2021 water shortage that led to record low levels in Lake Powell. Although levels have slightly improved due to heavy snowfall in recent years, the reservoir remains far from full. The study emphasizes that severe shortages can arise from both climate change and natural variations in streamflow, which could have devastating effects on the critical reservoirs in the region serving around 40 million people. The lead author of the study, David F. Gold, underscores the importance of integrated management approaches that consider interconnected sectors and are scientifically informed to preserve resilience in the face of increasing pressures on water resources.
The research serves as a wake-up call for policymakers and stakeholders involved in managing water resources in the Colorado West Slope basins. It highlights the urgency of adopting advanced drought analysis methods and integrated management approaches to address the interconnected impacts of climate change and natural variability on water availability. With the potential for severe shortages and unsustainable water delivery levels looming, it is essential to take proactive steps to ensure the resilience of the region’s water supply systems. The study’s findings underscore the need for continued research and collaboration among scientists, policymakers, and water resource managers to develop strategies that can mitigate the impacts of climate change and secure the long-term sustainability of water resources in the Colorado River Basin.
