Dry Soils And Historic Drought Are Exacerbating Flash Floods In Utah
Monsoon season weather is here in southern Utah and flash flood alerts from the National Weather Service are frequent.
The state’s historic drought is exacerbating these kinds of weather events, according to Jon Meyer, a climatologist at Utah State University’s Utah Climate Center. He said the moisture in the soil is near record lows, and the dry, crusty ground isn’t able to absorb the water when it comes.
“When you get really intense rainfall rates over a short period of time; that water can't get down into the soil very quickly,” Meyer said. “There's almost like … a candy coating shell on the land surface and that water, instead of going into the soil, just runs right off.”
Flood waters ripped through Zion National Park last month, pushing debris and mud into the nearby town of Springdale. There were no injuries reported, but some structures were impacted including the Zion Canyon Medical Clinic, which had to close its doors because of the damage.
Amanda Rowland, a spokesperson for the park, said flooding can happen with little warning in the area, especially along one of the park’s most popular trails — the Narrows.
“You have these towering walls and beautiful scenic views,” she said. “However, it could be blue skies over your head and that unseen thundercloud or thunderstorm could be to the north.”
Rowland said visitors who aren’t familiar with the southwest’s monsoons need to be extra cautious when going to Zion, as well as surrounding parks. She said visitors should plan ahead and make decisions based on current weather conditions.
Though the monsoonal rains may seem like relief for the water-parched state they do very little good, said Meyer. He believes the kind of rainstorms the state needs are long ones that stretch for multiple days so the water can percolate through the soil.
“[These storms] almost have no drought relief impact from them because there's almost no infiltration into the soil,” Meyer said. “We might see a little bit of [the rain] getting down into the topsoil, but very little of it makes it beyond that. And because we're so hot right now … whatever we get in the topsoil tends to just evaporate out over the next few days.”
The weather service cautions people to avoid low areas and any pooling water when there’s an expected downpour.