Could it happen here? Experts weigh New Mexico's risk for catastrophic flooding

Over the weekend, flooding devastated the Texas Hill Country beginning before dawn on July 4, wiping away mobile home parks, pummeling campground cabins and claiming the lives of more than 84 people in Kerr County alone — where the worst of the flooding occurred — and around 100 across the state. With scores still missing, that number is likely to increase.

While an event with this number of casualties hasn’t occurred in the Texas Hill Country prior, the area is susceptible to flooding. Mass casualty events due to flooding have taken place there over the last 30 years, including when rivers swept away subdivisions in Comal County — a semi-remote area northeast of San Antonio — killing nine in 2002, and flooding across central and southeast Texas in rural and urban areas alike claimed the lives of 31 in 1998.

While Texas and New Mexico share a border, the two states differ drastically in terms of terrain and population size. Still, the question lingers in a state that has seen its fair share of natural disasters, including flooding. Could this happen here?

“The short answer is yes, of course, it could absolutely happen here,” Joseph Galewsky, chair of the University of New Mexico’s Earth and Planetary Sciences Department, said in an interview.

He said that for such an event to happen, the correct set of meteorological conditions would have to be in place and a huge amount of water would have to be dumped in one particular location.

“Here in New Mexico, with mountainous topography, you can get situations where thunderstorms are kind of locked onto the topography and get a huge amount of rainfall in one location,” Galewsky said. “Those mountainous catchments are where you can get significant flash flooding. Also during the monsoon, we get a lot of water vapor coming up from the Gulf of Mexico and the Gulf of California and that's another condition that you need to have, that we do have here in New Mexico.”

He added that another factor that could cause flooding in New Mexico is the effects following wildfires, such as burn scars, which can get “enormous amounts of runoff really quickly.”

Burn scars are a concern that the state’s highest elected official shares as well.

“Due to the drought conditions, we know that most of our state can be at risk for flash flooding. We also know that our burn scar areas are extremely prone to flooding. Drought and wildfire can prevent the ground from absorbing the rainwater, so even a half-inch of rain can cause flash flooding in some areas,” Michael Coleman, spokesperson for Gov. Michelle Lujan Grisham, said in a statement.

He also said the state has made investments to mitigate the effects of flooding in its most vulnerable areas, citing technology developed by the Department of Homeland Security and Emergency Management and the U.S. Geological Survey being utilized in Hermit’s Peak/Calf Canyon and South Fork burn scar areas to help local governments “plan and implement projects needed for mitigation.”

Another factor that differs in New Mexico and Texas is the amount of rainfall the two states get. San Antonio nets an average annual rainfall of nearly 33 inches, while Albuquerque's is just 9 inches, according to the cities' respective tourism websites.

“It would take a lot less rainfall to result in that kind of flooding in New Mexico. I don't remember any events where we had 15 inches of rain in New Mexico,” Byron Morton, chief meteorologist for Journal partner KOAT TV, said.

Rainfall levels reached up to 15 inches Friday — far less than initially predicted — across south-central Kerr County, causing the Guadalupe River to rise 22 feet over the course of just three hours, according to the San Antonio Express-News.

“As far as the terrain and the geology, the topography, certainly the higher terrain of New Mexico could mimic that,” Morton said. “These events are becoming more probable because of our warming climate, and for every one-degree rise in temperature, we get a 4% rise in atmospheric water vapor. So you think you got a sponge, and you keep making a bigger sponge that's going to hold more water, you ring that bigger sponge out, you're going to get more water from that sponge.”

Notification and federal cuts

A debate has sparked around how the federal cuts touted by the Trump administration may have impacted the National Whether Service's forecast.

However, Galewsky said the NWS accurately predicted the heavy rainfall in Texas.

“Whenever these events happen, almost without exception, you'll hear somebody in government say, 'nobody foresaw this ...' and they're almost always wrong, and that is definitely the case here,” Galewsky said. “From everything I can tell, the NWS did their job. Flash floods are really, really hard to forecast."

For his part, Morton said that federal cuts to NWS have made it more difficult to put out accurate forecasts with less data to operate off of and questioned, in light of the Texas floods, if this is the right time for slashing their staffing.

“I think we should use this as a learning lesson. A, that we need to be more aware of our surroundings and what we're doing when we're doing it. And B, do we want to cut the funding to the programs that are trying to protect us from these events and trying to get the information to us?” Morton said. “We are in a changing climate now … extreme weather events are going to become more common, and that's what we're seeing.”