Across the nation, dams and reservoirs play a critical role in water supply, flood control, and recreation. Observations of these vital water bodies reveal varied storage levels, with some regions experiencing surpluses due to increased precipitation or snowmelt, and others facing drought conditions that lead to lower than average water levels. These conditions are consequential not only for the immediate areas around the reservoirs but also for downstream water users and ecosystems that depend on consistent water flows.

For instance, Lake Powell in Arizona exhibits water storage levels significantly below its average, reflecting broader regional challenges of extended drought and high water demand in the Colorado River Basin. Conversely, reservoirs like Lake San Antonio in California have observed increased storage, benefiting from recent rainfall surges. Such disparities underscore the complex dynamics governing water resources, influenced by factors such as climate patterns, water management policies, and infrastructure efficiency. The hydrological status of these reservoirs carries implications for water security, agricultural irrigation, recreational opportunities, and environmental conservation, stressing the importance of adaptive water management strategies to mitigate the impacts of extreme hydrological events.

The history of reservoirs and dams in the USA is closely tied to the country's development and growth. Major river systems like the Colorado, Columbia, and Missouri have been extensively dammed to provide water for irrigation, hydropower, flood control, and recreation. Many of these dams were constructed in the mid-20th century, during a period of rapid infrastructure development, and have since played an essential role in the country's economy and society.

The US has a vast network of dams and reservoirs, with over 90,000 dams across the country, including 2,500 major dams. Many of these dams are located on major river systems, such as the Colorado River, where they have significant hydrological impacts on the river's flow and ecosystem. Dams can also have important climatic impacts, influencing the amount of water available for irrigation, and potentially affecting regional climates. For example, the construction of large reservoirs in arid regions like the Colorado River basin can lead to increased evaporation rates, reducing the amount of water available for other uses. Additionally, climate change may exacerbate existing hydrological and climatic concerns, potentially leading to more frequent and severe droughts and floods in certain regions.