The healthy cache of water in back-to-back years marked a significant healing from the drought and low water levels experienced from 2019 to 2022. The U.S. Bureau of Reclamation, which manages the dam, momentarily increased water releases to as much as seven times the winter season standard rate to develop area for water from future storms and to reduce flood risk downstream. According to a recent report from the California Department of Water Resources, managed groundwater recharge added 4.1 million acre-feet– nearly one full Shasta Lakes worth of water– to underground reservoirs in the last water year (October 2022 through September 2023). The agency approximates it would take 5 successive above-average water years to make up for the deficit sustained over the previous two decades.NASA Earth Observatory images by Wanmei Liang, using Landsat information from the U.S. Geological Survey and surface area elevation data from California Department of Water Resources.
Satellite picture of Shasta Lake caught on April 24, 2022, by the Operational Land Imager-2 on Landsat 9. Satellite image of Shasta Lake captured on May 7, 2024, by the Operational Land Imager on Landsat 8. For the 2nd year in a row, Californias largest tank filled to almost 100 percent capacity.Following successive wet winter seasons, Shasta Lake in Northern California reached complete capacity for the 2nd year in a row, in time for summertime 2024. As the states biggest reservoir, crucial for watering, local water supplies, flood control, and more, it likewise neared 100 percent capability in the spring 2023. The healthy cache of water in back-to-back years marked a substantial healing from the dry spell and low water levels experienced from 2019 to 2022. On May 7, 2024, the Operational Land Imager (OLI) on the Landsat 8 satellite recorded the above image (lower) of Shasta Lake, showing it at 96 percent of its total capacity, which is 114 percent of the average for that date. In contrast, the image above (upper) taken by Landsat 9 on April 24, 2022, showed the lake at only 39 percent capability. That May, the reservoir peaked for the year at a mere 40 percent of its total capacity.An extended period of severe drought, starting in 2019, left reservoir levels low for several years. However in the early months of 2023, heavy rains and meltwater from an above-average mountain snowpack initiated an exceptional rebound. By May 29 of that year, the lake had actually filled to 98 percent of capacity. The tan fringe, or “bathtub ring,” around its border that showed up in 2022 had vanished.In 2024, Shasta Lake water levels again began rising rapidly in mid-January as moisture-laden storms passed through the region. However as this chart reveals, lake elevations at the start of the year were much higher in 2024 than in 2023. By mid-February 2024, authorities deemed the tank “too expensive” for that time of year, according to news reports. The U.S. Bureau of Reclamation, which handles the dam, momentarily increased water releases to as much as seven times the winter season baseline rate to produce space for water from future storms and to lessen flood threat downstream. It was the very first time since 2019 that managers had to conduct this sort of flood control.The early 2024 rainfall was an advantage to other water supplies in California. Lake Oroville, the states second-largest tank, likewise reached full capacity for the second year in a row. Even with controlled water releases throughout the winter season, the tank held 128 percent of its typical capacity in early May 2024. Surface area water is but one part of the image in California. Groundwater comprises 40 percent of the states supply of water in common years and can contribute as much as 60 percent in dry ones. According to a current report from the California Department of Water Resources, handled groundwater recharge included 4.1 million acre-feet– nearly one full Shasta Lakes worth of water– to underground tanks in the last water year (October 2022 through September 2023). This was the first annual gain in groundwater shops recorded because 2019. The company estimates it would take 5 consecutive above-average water years to make up for the deficit incurred over the past 2 decades.NASA Earth Observatory images by Wanmei Liang, utilizing Landsat information from the U.S. Geological Survey and surface area elevation information from California Department of Water Resources.
