PENNSYLVANIA RESERVOIR REPORT

Last Updated: December 22, 2025

As of the latest observations on December 22, 2025, Pennsylvania's dams and reservoirs exhibit varied conditions in water storage levels, which are crucial for water supply management, flood control, and ecological balance. The Prompton Reservoir is marginally below its average elevation of 1125.34 feet, with a current level at 1125 feet, suggesting a slight deficit in storage. Conversely, the General Edgar Jadwin Reservoir is slightly above its average at 990 feet, compared to the norm of 989.21 feet, indicating a minor surplus. Beltzville Lake near Parryville is experiencing a noticeable decrease in water levels, with a current elevation of 624 feet versus an average of 627.57 feet, which may concern local water managers. Similarly, Blue Marsh Lake and Indian Rock Dam are both below their average elevations, 287.91 and 375.38 feet respectively, registering current levels at 285 and 371 feet. Lake Arthur at Moraine State Park stands at an average level of 1190.19 feet, maintaining a near-normal elevation at 1190 feet.

These deviations from average storage levels could be indicative of a range of factors such as changes in snowpack, precipitation patterns, and river flows. The lower than average elevations observed at Beltzville Lake, Blue Marsh Lake, and Indian Rock Dam could potentially be linked to reduced snowpack or lower rainfall in the region leading up to December. The slight increase in the General Edgar Jadwin Reservoir may suggest either an anomaly in inflows or a managed decision to retain more water. Since the data provided does not include specifics on weather patterns or management decisions, these observations warrant further investigation to determine the causes. It is critical for authorities and stakeholders to monitor these conditions continuously, cross-referencing with meteorological data and water usage reports to ensure sustainable reservoir management and to address any potential impact on local ecosystems and communities.

Pennsylvania has more than 3,000 dams and the majority of them are used for flood control, irrigation and recreational purposes. Some of the major reservoirs in the state are Raystown Lake, Lake Wallenpaupack, and Blue Marsh Lake. These reservoirs are supplied by streams, rivers and creeks such as the Juniata River and the Lackawaxen River. The snowpack in the Pocono Mountains and the Allegheny Mountains contributes to the water supply of these reservoirs. The hydrology in the area is influenced by the Appalachian Mountains and the Atlantic Ocean. The state has experienced record low water levels in some reservoirs during drought conditions. Seasonal trends show that water levels are typically highest in the spring due to snowmelt and lowest in the fall. Overall, these reservoirs play a crucial role in supplying water for the state's agriculture, industries and residents.

Pennsylvania has more than 3,000 dams and the majority of them are used for flood control, irrigation and recreational purposes. Some of the major reservoirs in the state are Raystown Lake, Lake Wallenpaupack, and Blue Marsh Lake. These reservoirs are supplied by streams, rivers and creeks such as the Juniata River and the Lackawaxen River. The snowpack in the Pocono Mountains and the Allegheny Mountains contributes to the water supply of these reservoirs. The hydrology in the area is influenced by the Appalachian Mountains and the Atlantic Ocean. The state has experienced record low water levels in some reservoirs during drought conditions. Seasonal trends show that water levels are typically highest in the spring due to snowmelt and lowest in the fall. Overall, these reservoirs play a crucial role in supplying water for the state's agriculture, industries and residents.