Commentary: San Gabriels’ catchment channels a river
Just as we thought the fever had subsided for the stream that gurgles merrily all year long down the ineptly named Arroyo Seco, last weekend’s storm prodded it back into a rage. Wider and higher and faster than at any time in years it roared through its narrow gulch. Nothing could have stood up against its fury.
Hiking alongside it from a mile or two upstream — sorry, upriver — from JPL, you’d say it was sweeping everything before it except there was almost nothing left to sweep. Whatever even hefty tree limbs had been sleeping peacefully in the dry bed since the Great Fire, whatever tiny creatures had built homes there during the five years of drought, whatever plants had been lulled by the low water levels had already been swept away in previous floods following this year’s record rainfalls. Those victims forgot the basic rule of nature — nothing stays the same — and paid the price.
The San Gabriel Mountains, through which our valley wends its way, are among the steepest in North America, which means the runoff is at breakneck speed. It also means that the catchment areas for virtually all streams are very small. So normally a few hours after even a heavy downpour the water level is back close to what it was.
The only other place where I’ve lived like this is in the Virginia suburbs of Washington, D.C., where the short streams tumble into the Potomac. I remember driving from work one summer evening and seeing the usual dried-up valley, only to learn when I got home that a child had been drowned there in a thunderstorm earlier that day. It’s for that reason that they are called not “streams” but “runs.”
The Arroyo Seco differs not only from them but from any miles around in having a much bigger catchment area: that’s why it has the only flowing water all year. Every drop of rain on the huge bowl of mountains that surrounds the Arroyo that is not evaporated finds its way into this one outlet, just as all the water flowing from the rivers of Northern California has to find its way through the Golden Gate.
I have to admit this is no San Francisco. But walking on the path through vegetation that ranges from big trees to giant cactus plants with the valley sides towering 1,000 feet above and the river wriggling its way so much that you don’t know if you are going north or south is a thrill in any weather. Often, as I look at it, an imaginary phrase comes to mind. “Are we in Los Angeles yet, Daddy?”
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REG GREEN is a La Cañada resident. Readers of his Valley Sun commentaries may be interested to know that he wrote a moving op-ed about the killing of his 7-year-old son, Nicholas, that was published in the Los Angeles Times on Feb. 13. It can be found here.