UPPER-SAN-JOAQUIN-TOTAL RESERVOIR REPORT

Last Updated: December 30, 2025

Across the nation, dams and reservoirs play a crucial role in water storage, flood control, and maintaining ecological balance. However, varied conditions such as precipitation patterns, snowmelt rates, and consumption demands have resulted in a mixed picture of water storage levels. Some reservoirs are experiencing higher-than-average storage levels, indicative of surplus water availability. Conversely, others are grappling with lower levels, which may signal drought conditions or increased water usage that could impact regions dependent on these water sources for agriculture, drinking water, and industrial use.

A snapshot of the current conditions reveals that reservoirs such as Lake Winnipesaukee in New Hampshire and Indian Lake in New York are holding water levels close to their averages, which signals stable water supply conditions. However, the Wanaque Reservoir in New Jersey is significantly below its average, raising concerns about potential water scarcity. Similarly, Maurice R at Union Lake Dam in New Jersey has seen a drastic reduction in streamflow. In contrast, the General Edgar Jadwin Reservoir in Pennsylvania and Blue Marsh Lake are slightly below average but not yet at alarmingly low levels. On the opposite spectrum, reservoirs like the John Martin Reservoir in Colorado and Elephant Butte Reservoir in New Mexico are holding much less water than average, pointing towards drought stress. Meanwhile, elevated storage levels at reservoirs like Lake Mead in Nevada and Lake Powell in Arizona are not necessarily signs of surplus but rather fluctuations in water management strategies. These variations in reservoir conditions underscore the complex interplay between natural water cycles and human management, necessitating careful monitoring and adaptive strategies to ensure water security for communities and ecosystems alike.