Will Tropical Storm Hilary Impact Lake Mead Water Levels?

Tropical Storm Hilary is expected to bring heavy rainfall and possible flooding to the Las Vegas Valley. Residents are concerned about the impact on Lake Mead water levels.

LAS VEGAS (KLAS) -- Brace yourselves, Las Vegas Valley residents, because Tropical Storm Hilary is on its way, bringing with it rainfall, thunderstorms, and the potential for flooding. As we prepare for this record-setting storm, many are wondering how it will impact the water levels of Lake Mead, especially considering the possibility of heavy rain and flash flooding in the mountainous areas of southern Nevada.

When the wet winter storms hit the Las Vegas Valley back in January, the National Weather Service tried to manage expectations. They explained that while rain in the valley does contribute to Lake Mead's water levels, it's more like a drop in the bucket compared to the significant contribution from the snowpack in the Upper Colorado River Basin. Fortunately, this year's record snowpack has helped alleviate drought concerns in Nevada and other Southwest states.

In January alone, Lake Mead experienced a 2-foot rise in water levels, going from 1,044.96 feet on January 1st to 1,046.96 feet on January 31st. During that same period, southern Nevada received above-average rainfall.

Now, as we await the arrival of Tropical Storm Hilary, forecasters predict that it could bring anywhere from 1 to 3 inches of rain, with the potential for up to 5 inches in the mountainous regions where the heaviest rain is expected. A flood watch has been issued for southern Nevada until Monday afternoon.

Hilary is expected to maintain its status as a tropical storm as it moves into central Nevada early Monday before dissipating. However, it's still uncertain whether the rainfall from this storm will be comparable to that of January. Doug Hendrix, a Public Affairs Specialist from the Bureau of Reclamation, has stated that the precipitation from the early-2023 storms did have an impact on Lake Mead's water levels, but it was not enough to reverse the historic lows the lake has been experiencing.

In response to the potential threat, Clark County Manager Kevin Schiller has declared a State of Emergency for Clark County, where Lake Mead is located. Officials are urging residents in the area to prepare for flash flooding.

Furthermore, a large portion of Nevada is currently under a high wind warning until 5 a.m. local time on Monday, along with a flash flood warning until 5 p.m. Monday.

As of Sunday afternoon, Tropical Storm Hilary had already made landfall along the coast of Baja California in Mexico.