Saturday, November 30, 2013


Neptune Avenue in Encinitas (or Leucadia, to be a bit more precise) has three places you can access the beach, Stone Steps, Beacons, and Grandview.  Beacons is the only one where you aren't squeezed into a street end or narrow path between bluff top homes.  Apparently, it got its name from a World War II vintage beacon at the north end that is now long gone (Beacon's Beach). The apostrophe may date to a restaurant named Beacon's that was reported to have been here in the 50s and 60s.

The park has a switchback trail down the bluff. The whole segment looks like an old slide scar, which sort if fits with the geology of this whole stretch.


This segment of beach and bluffs is an interesting contrast to the section at Stone Steps. Both are cut into the 80' sandstone face of the marine terrace. But at Stone Steps, the bluffs are steeper and appear to be subject to shallow failures, but the bluffs at Beacon's seem to fail as deeper slumps, several hundred feet long. There was a lot more water seeping out of the lower bluff and some indication of an impermeable zone - older fine-grained sediments nearer beach level - that might explain the different slope behavior.

Of course, this is all based on brief superficial observations and virtually no knowledge of the local geology, so no one should even consider basing any serious geotechnical decisions on my speculative rambles!

At Stone Steps, erosion control was largely achieved with seawalls, but here folks have resorted to an amazing variety of much more complex slope engineering measures - at the top, bottom, and middle of the slope.  But just as at Stone Steps, what has really saved these properties - and probably been largely subsidized by everyone else - is beach nourishment.

At the north end of Beacons, the armored toe of the slope extends much farther seaward than elsewhere along here and seriously impacts beach walking at higher tides. It was probably much worse before the 2012 nourishment. My first guess is that this is an old slide and the property owners simply armored the toe where it pushed out across the beach, creating a bottleneck for posterity.  A private toll house on a public highway.

More photos of Encinitas over at hshipman.

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