FLUVIAL GEOMORPHOLOGY
ALDER CREEK OBSERVATIONS
Alder is beautiful creek in midsouth Big Sur. I made my observation around the mouth of the river as it flows into the sea.
There are many interesting aspects to the creek. As many do in Big Sur, it flows through a constructed drainage tunnel under Highway 1 as it enters the sea. Furthermore complicating factors come from the massive slides common in the southern half of Big Sur. The highway itself has not been open in both directions on the stretch from Cambria to Carmel in almost two years.
In many ways, the stretch from Cambria to the closure is a geomorphologists dream… ranchland alternating with protected area up until San Carpoforo Creek, and steep mountains north of that. Heavier rock like serpentine upon less heavy pole Monterey shale and the nature of the fault contribute to constant sliding. I don't have the best grasp of geology, but I've often heard the fault activity compared to sliding a pizza under a
door.
As for my observation, there's a beautiful creek there until it hits Highway 1. Slide effects are visible(I know from study it was 2015) and can easily be demarked by abundance of phragmites, not to mention construction. Proper observance of the creek involved scampering down large rocks, and into a drainage tunnel. Water is flowing even without recent rain, denoting presence of spring fed stream constant in the area. The drainage tunnel constricts a wide, diverse creek. Though the tunnel is relatively, the transfer to the entrance narrows the width of the water to only a few inches on the in and out of the tunnel I was surprised to see exactly how much the water has incised the concrete. Water would only spread out from that point in a period of heavy rain outside of the area near the end where a hole is visible from where the concrete was eroded entirely.
The tunnel flows directly out into the beach and ocean. It's a shame to see it constricted but as highway 1 exists I'm not sure what an alternative would be.
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