Borrego Sun - Since 1949

Nature Watch: Flash Floods


Last updated 7/13/2021 at 2:09pm

Any day now, summer skies in Borrego will fill with billowing thunderheads as monsoon storms push up from the Gulf of California.

It's a dramatic change for the blank, blue sky of summer. The rolling thunder, nighttime light shows, and big drops of rain can also be a welcome change to the summer heat. Sometimes, however, the thunderstorms that come with seasonal monsoons can bring torrential rains that will damage property, change the landscape and be life threatening for people in the wrong place at the wrong time.

While almost every summer sees some localized flash flooding, the big events are more infrequent.

In 2004, and again in 2013, larger flash floods swept down from the San Ysidro Mountains, gushing from Palm Canyon and damaging Palm Canyon Campground and flooding homes at De Anza Country Club.

A flash flood can be a sudden and dramatic event, but also deadly. Summer travelers should be alert to these dangers and take precautions that could save their life.

I can recall being in Glorietta Canyon on a 108-degree summer day when dark clouds boiled overhead. In less than five minutes, high winds arrived along with torrential rain and temperatures dropped into the low 80's. Within minutes there was an inch of water flowing down the wash and I wisely moved to higher ground. Soon there was several feet of rushing water sweeping away anything in its path and there was no place to go. For the next hour I had a safe, ringside seat as rocks, brush and even a huge trunk of a native palm washed down from the canyons above.

In 2012, desert visitors had come to hike to the Wind Caves in Split Mountain when a flash flood arrived. Fortunately, they were not in their truck when a wall of water swept down Fish Creek, taking their vehicle with it. It's not likely they would have survived.

While flash floods are fascinating to watch, there are a few things to keep in mind as Monsoon season arrives.

Know the weather report. Local media will be filled with alerts that there might be flash flooding.

Keep an eye out. If you see thunderheads building, stay out of deep canyons and washes.

Always have a safe place identified. If rain starts or you hear distant thunder, seek high ground. You may be stranded awhile, but you will be safe.

Carry extra water and food so you can ride out the flood comfortably.

Summer thunderstorms are just another one of the fascinating events of nature to enjoy in Anza-Borrego.