Friday January 13, 2023
Monterey County Now —
Why is it that, on the nicest day of weather in the past few weeks, the Salinas River, in the lower Salinas Valley, was expected to potentially rise so high as to force closures of Highway 68, Davis Road and Highway 1, and turn the Monterey Peninsula into an “island”? (Which has not happened, at least yet.)
In short, because the Salinas River is hard to predict, for a variety of reasons. But perhaps the first thing one must understand is how huge the Salinas River watershed is: The river’s headwaters are east of San Luis Obispo—the river is 175 miles long and drains a watershed of 4,160 square miles—and once it’s flowing in sustained heavy rains, there are countless tributaries flowing into it across most of the Central Coast.
Of those, the largest one that is undammed is the Arroyo Seco River, where flows reach the lower valley much faster than the upper tributaries. The water from those upper tributaries can take days to reach the lower valley, and spread out along the way.