Floods are bad enough, but adding the adjective “flash” makes them deadlier in Southern Nevada.
The summer monsoons can generate cloudbursts that spawn floods as water roars through washes, diversion channels, and streets. People and vehicles can be swept away by the floods, which kill more people in Clark County than any other natural disaster, causing at least 35 deaths since 1960.
The homeless, who frequently camp in washes and storm drains, face particular risk. Floods can materialize without warning as channels quickly fill with water that fell as rain miles away.
Erin Neff, public information manager for the Regional Flood Control District said underground storm drains, which often have metal bars at their entrances to keep debris out, can quickly become death traps for those stuck inside.
“When you see … shopping carts and mattresses piled and stacked on top of metal, you know, no one can survive that,” Neff told State of Nevada.
Neff helped coroner’s investigators navigate the tunnels in 2016 following the drowning of a homeless woman.
“You can imagine how horrible that death would have been. It is heartbreaking. It is preventable,” Neff said. “And they live there by choice and it is a very sad situation.”
The flood control district works with social service partners during the rainy season to make those in tunnels aware of the risks.
"When we know for example, like this week, that we have monsoon moisture, that the potential is there for storms, we ask them to go and really ramp up their outreach," Neff said. "We don't have the resources or the connections to walk into these tunnels, but the people that do are well aware of the weather."
The Southern Nevada flood season runs from July through September. The summer monsoon storms arise as high-altitude wind currents bring in moist air from the Gulf of Mexico. Heat pushes that air higher, where the moisture condenses, forming massive cumulonimbus clouds that can unleash powerful storms.
Neff said Southern Nevada is experiencing a typical monsoon season after two years of what she called "nonsoons," which provided little rain.
"All the long-term climate modeling suggests we could have prolonged periods of drought here punctuated by highly intense storms," she said. "So yes, big storms are still possible here."
Erin Neff, public information manager, Regional Flood Control District
