PENNSYLVANIA RESERVOIR REPORT

Last Updated: January 11, 2026

Pennsylvania's dams and reservoirs play a vital role in water supply, flood control, and recreation. As of the latest observations on January 11, 2026, several reservoirs are reporting water levels that deviate from their average measurements, indicating varying conditions across the state. The Prompton Reservoir and the General Edgar Jadwin Reservoir are slightly above their average water surface elevations, at 1126 feet and 991 feet respectively, compared to their norms of 1125.34 feet and 989.22 feet. Conversely, Beltzville Lake near Parryville, Blue Marsh Lake, and Indian Rock Dam are reporting lower than average levels, with Blue Marsh Lake showing the most significant drop at 285 feet versus its average of 287.9 feet. Lake Arthur at Moraine State Park remains stable, nearly mirroring its average at 1190 feet.

These abnormal conditions could be attributed to various factors such as seasonal weather patterns, local precipitation, and river flow changes. The elevated levels at Prompton and General Edgar Jadwin may be influenced by recent rainfall or upstream snowmelt, while the lower levels at Beltzville, Blue Marsh Lake, and Indian Rock Dam could suggest either reduced precipitation, increased water usage, or management operations to maintain downstream flow requirements. It's worth noting that while some fluctuations are normal, ongoing monitoring is crucial to ensure that water resources are managed effectively to mitigate potential risks such as drought or flooding. Further cross-referencing with additional data sources like river flow records and snowpack levels would provide a more comprehensive understanding of the causes behind these conditions.

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.