Tropical Storm Hilary, which has dumped heavy rain and caused flooding across California and other parts of the southwestern United States, has led to a rise in water levels at the drought-stricken Lake Mead reservoir for the second consecutive day.
Before the remnants of the storm arrived, Lake Mead’s water levels stood at 1063.49 feet on August 20. After the first day of rainfall on August 21, the reservoir saw an increase to 1063.62 feet. On the second day of Tropical Storm Hilary’s impact on August 22, Lake Mead’s water elevation increased further to 1063.78 feet according to readings by the U.S. Bureau of Reclamation.
While the rises in water levels are relatively small so far, any increase is considered noteworthy for the reservoir that provides water to approximately 25 million people living across the Colorado River Basin states of Arizona, California, Nevada, New Mexico, Utah, Colorado, and Wyoming.
Lake Mead has been mired in a dire situation after years of drought conditions intensified by climate change, with water levels reaching record lows last year. In summer 2022, the water level dramatically plunged to 1,040 feet above sea level, triggering concerns amongst water management officials about reaching “dead pool” status, in which water can no longer be released downstream due to extremely low levels.
Forecasters had warned of potential flash flooding in areas around Lake Mead as the remnants of Hurricane Hilary, which was downgraded to a tropical storm, made its way north from Mexico. The heavy rains arrived in the region on August 21 leading to flooding that closed major highways and roads around Las Vegas.
While the water level increases are still relatively minor, they come as good news for the parched region. However, experts say the rainfall from Tropical Storm Hilary will likely not provide long-term relief, emphasizing that more consistent precipitation over a number of wet seasons will be required to refill Lake Mead.
The effects of climate change on weather patterns, bringing increased frequency of drought, have been identified as the primary cause of declining water levels in Lake Mead. After bone dry conditions throughout summer 2022, Lake Mead saw a substantial rise in water elevation from the beginning of 2023 up until now due to an extremely wet winter.
At the start of January 2023, Lake Mead’s water level stood at just 1,044 feet. Significant winter snowstorms helped build the snowpack, leading to increased spring runoff and inflow into Lake Mead. The reservoir’s water level climbed to 1,047 feet by April 25 and then rose rapidly to 1,054 feet by the end of May. The arrival of Tropical Storm Hilary has now bumped up levels even further as the region hopes for more wet weather over the coming months to provide some extra security.