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 Solana Beach Coastal Preservation Association
August 20, 1998
Project No. 1831
Page 41
347 to 403 Pacific Avenue and 417 to 423 Pacific Avenue. Areas outside the identified
address ranges may have experienced block falls early in the period of wave attack but lack
fresh scars because of subsequent marine erosion. Remaining notches range up to 6 feet
in depth, but overhangs locally range up to 9 feet. Steep and near-vertical scars extend as
high as elevation 60 feet at 371 Pacific Avenue.
The sand beach varies from 0 to 20 feet in width, extending up to elevation 5 feet at the
base of the sea cliff in the cove at the north end. Small areas of shingle beach exist along
the base of the cliff. Offshore, the shore platform has a thin, discontinuous layer of sand
up to 18-inches thick (Figure 5). The near-vertical sea cliff rises to elevation 24 to 26 feet.
The bluff rises at a slope angles of 43 to 50 degrees to an elevation of 72 to 88 feet. Sea
caves extend up to 16 feet into the cliff.
Comparison of the 1990 and 1998 topographic profiles in Cross Sections 3 through 10
suggests an average 6 feet of retreat of the sea cliff in the last eight years, varying from zero
at 417 Pacific Avenue (south of the sea cave) to 15" feet at 261 Pacific Avenue. Photo 13
shows extensive overhangs below 235-241 Pacific Avenue, like those that formed as a
precursor to the block falls that occurred immediately to the north. Accelerated subaerial
erosion affects nine areas of marine terrace deposits along the bluff. Active over-bluff
drainage appears to descend from beneath the gunnite slope surfacing below 235 Pacific
Avenue.
During the 1982-83 storm season, the sea cave below 417/423 Pacific Avenue enlarged
somewhat, with a partial roof collapse of the seaward overhang undermining upwards of 10
feet of the upper terrace deposits, leaving a fresh scar at the base of the sloping upper
bluff, similar in appearance to the numerous other scars in this reach today. Based on
discussions with Mr. Folgner, the owner at 417 Pacific Avenue, the scar at the base of the
upper sloping bluff remained relatively stable for the first 8 to 10 years, with upper bluff
failures eventually propagating up the face of the upper bluff, ultimately resulting in 4" feet
of upper bluff retreat and the resulting upper bluff scar visible in Photo 4 today.
The sea cave, below 417/423 Pacific Avenue was unsuccessfully filled during this past
year=s storm season. The concrete infill appears to have been undermined, thus allowing it
to settle and pull away from the roof. Erosion and flanking of this sea cave infill may have
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