Groundwater, reservoir levels remain at historic lows, but rainwater and flooding should help

Record snowfall and rain have helped to loosen drought’s grip on parts of the western U.S. as national forecasters and climate experts warned Thursday that some areas should expect more flooding as the snow begins to melt.

The winter precipitation wiped out exceptional and extreme drought in California for the first time since 2020, the National Oceanic and Atmospheric Administration reported Thursday in a seasonal, nationwide outlook that came as parts of the state are under water. In neighboring Nevada, flood warnings were in effect and rushing water prompted some evacuations overnight in one of Arizona’s tourist towns.

Elsewhere, NOAA’s forecast warned of elevated flood risks from heavy snowpack this spring in the upper Midwest along the Mississippi River from Minnesota south to Missouri.

Despite the receding drought, experts cautioned that the relief may be only a blip as the long-term effects persist from what has been a stubborn dry streak.

Groundwater and reservoir storage levels — which take much longer to bounce back — remain at historic lows. It could be more than a year before the extra moisture has an effect on the shoreline at Lake Mead that straddles Arizona and Nevada. And it’s unlikely that water managers will have enough wiggle room to wind back the clock on proposals for limiting water use.

That’s because water release and retention operations for the massive reservoir and its upstream sibling — Lake Powell on the Utah-Arizona border — already are set for the year. The reservoirs are used to manage Colorado River water deliveries to 40 million people in seven U.S. states and Mexico.

MYSTERIOUS FRESHWATER RESERVOIR FOUND HIDDEN BENEATH THE OCEAN

Lake Powell could gain 35 feet as snow melts and makes its way into tributaries and rivers over the next three months. How much it rises will depend on soil moisture levels, future precipitation, temperatures and evaporation losses.

Paul Miller, a hydrologist with the National Weather Service’s Colorado Basin River Forecast Center, said that sounds like a lot of water for one of the nation’s largest reservoirs, but it still will be only one-third full.

“It’s definitely moving in the right direction, but we’re far from filling the reservoirs in the Colorado River system and we’re far from being at a comfortable point from a water supply perspective,” Miller said during Thursday’s NOAA briefing.

Federal forecasters outlined other predictions for temperature, precipitation and drought over…