Sunday, March 6, 2016

Never enter the riverbed

Rio San Gabriel riverbed

On a typical weekend day, the Rio San Gabriel riverbed is teeming with people—bikers, skateboarders, motorcyclists, even horseback riders.

Rio San Gabriel riverbed signBut we had a bit of rain last night, with more expected in the next couple of days. And the strongly worded warning sign at the entrance (OK, covered with graffiti but still legible) made me stop and think—just how likely, really, is a flash flood? After all, the sky is blue, with hardly a cloud in sight.

Flash flooding occurs when it rains rapidly on saturated soil or dry soil that has poor absorption ability. Many people tend to underestimate the dangers of flash floods. What makes flash floods most dangerous is their sudden nature and fast-moving water. And the source of the water might be a storm that occurs miles away. [Wikipedia]

So for today, anyway, unlike those two bicyclists in the picture, I stayed away from the floor of the riverbed.

Just in case.

2 comments:

  1. This is especially true for the San Gabriel River: The source of the San Gabriel River is those mountains we see to the North. They can get considerable rain and create a lot of run-off quickly.

    Most folks would be able to get up the bank in time if water started to rise. The biggest danger is when people try to wade through water that doesn't look deep, but turns out to be fast-moving. Once a person is knocked down in fast moving water, they are in real trouble.

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    Replies
    1. Frank, those bicyclists (two young boys) actually rode through the shallow water for a little bit as I watched. And even though it was very slippery, fortunately it wasn't fast-moving -- yet.

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