Declining Reservoir Reliability and Increasing Reservoir Vulnerability: Long-Term Observations Reveal Longer and More Severe Periods of Low Reservoir Storage for Major United States Reservoirs – Published on September 8, 2024
I am republishing this Open Access article as I think this will be new information for EconCurrents.com readers. I have published related articles recently which can be accessed HERE and HERE.
I have provided the below article in full but HERE is the link. I have highlighted some statements and my comments are either surrounded by brackets [] or in a text box
Citation: Simeone, C. E., Hammond, J. C., Archfield, S. A., Broman, D., Condon, L. E., Eldardiry, H., Olson, C. G., & Steyaert, J. C. (2024). Declining Reservoir Reliability and Increasing Reservoir Vulnerability: Long-Term Observations Reveal Longer and More Severe Periods of Low Reservoir Storage for Major United States Reservoirs. Geophysical Research Letters, 51(16), e2024GL109476. https://doi.org/10.1029/2024GL109476
Abstract
Hydrological drought is a pervasive and reoccurring challenge in managing water resources. Reservoirs are critical for lessening the impacts of drought on water available for many uses. We use a novel and generalized approach to identify periods of unusually low reservoir storage—via comparisons to operational rule curves and historical patterns—to investigate how droughts affect storage in 250 reservoirs across the conterminous U.S. (CONUS). We find that the maximum amount of water stored in reservoirs is decreasing, and that periods of unusually low storage are becoming longer, more severe, and more variable in (a) western and central CONUS reservoirs, and (b) reservoirs with primarily over-year storage. Results suggest that reservoir storage has become less reliable and more vulnerable to larger deviations from desired storage patterns. These changes have coincided with ongoing shifts to the hydroclimate of CONUS, and with sedimentation further reducing available reservoir storage. [Editor’s Note: Drought is natural. It is an error to asume that a period of drought is due to a changing hydroclimate. It may be or may not be. It just as well be the combination of the phases of the Ocean Cycles. To the extent that drought is caused by warmer temperatures we have a a better basis for attributing it to Global Warming. Same goes for increased evaporation from reservoirs.]
Key Points
- Low-storage periods are longer, more severe, and more variable in over-year storage reservoirs and in the western and central CONUS
- Longer periods of low storage for some regions in recent years suggests decreased reservoir reliability in a changing hydroclimate
- Maximum annual storage is also declining across CONUS, furthered by storage losses from sedimentation
Plain Language Summary
Drought in water systems is a major challenge in managing water resources. Reservoirs are important as they can lessen the impacts of drought on water availability for many users. However, they are impacted by drought as well. We use a novel and generally applicable method to identify when reservoir storage is unusually low, potentially from drought, at 250 reservoirs across the conterminous U.S. We find that the maximum amount of water stored in reservoirs is decreasing across the U.S. We also find that periods of unusually low storage are becoming longer and more severe in western and central U.S. regions as well as for certain types of reservoirs. This suggests that reservoir storage may be less reliable and more vulnerable to extreme conditions and may be further impacted by changing climate and hydrology across the U.S. and by sediment building up behind reservoirs.