College of Science

Geomorphic Systems students watch 15-20 foot swells rearrange the Monterey Bay beaches...

...during the first storm of the 2002-2003 season.

Seawall at Monterey Beach Hotel on 11/8/02. Note that the seawall precludes safe foot-traffic along the beach during these conditions.

Seawalls tend to reflect energy back to the shoreface, focusing, rather than reducing, erosive forces.

This is the seawall on 11/08/02.

This is the same view as above on 11/11/02, 3 days later. Note net sand loss. Compare this with photos taken one month later, after the sidewall collapsed and large riprap was used to fortify the base.

Each summer, weak but consistent wave energy gradually builds a broad flat beach as sand is slowly moved from off-shore sandbars up to the shoreface. Each winter, the mixture of wave energy and wave frequencies erodes the summer beaches, moving the sand to be stored in off-shore bars.

This is the seawall on about 12/21/02 soon after the parking lot was undercut. Large riprap was placed on the sides and front of the seawall to protect the hotel.

This is the same day as above.Note that the seawall precludes safe foot-traffic along the beach during these conditions. This is the "Peninsula Effect" that blocks people and sand migration.

Same day as above. Note that much more sand is eroded from right next to the seawall than from where the picture was taken. This is evidence that the structure accelerates sand erosion from the beach.

By March 5, 2003, after most of the hard winter storms had passed, the sand berm had built back up to cover the base of wall. Seasonal beach replenishment is a natural part of the annual cycle.

This is a closer view the same day as above.

Feb 29, 2004 shows the summer beach replaced by the winter beach. Note the deep shoreward indentation in the beach near the hotel. The coastline is retreating 0.7 m/yr here, so the seawall is left sticking out in the surf.

November 19, 2004 shows the 2004 summer beach washing away to the winter beach.

December 9, 2004 during one of the first big wave days of the winter 13.5 ft swells @ 16 sec period. This swell, combined with a tide of 5.98 ft, shows the hotel with a pronounced "peninsula effect."

October 18, 2007 during one of the first big wave days of the fall 11 ft swells and a rising tide. Access was cut off for the first time in several months as the tide rose.

Same as above. The large rip-rap buttressing the corner is still mostly buried, but the swash zone was beginning to cut away the summer beach berm.

January 5, 2008. The rip-rap along the seawall is exposed during a combination of high tide and storm surf.

Same as above with peninsula effect precluding passage in front of hotel. Stanchions in foreground supported a fence protecting dune habitat. Coastal retreat is reducing the width of dune habitat all along the southern Monterey Bay coast.

The "peninsula effect" is also apparent in this digital elevation model produced from 2003 NOAA LIDAR data. The rectangular outline of the hotel "footprint" juts into the beach and nearshore environment.

2004--Not far away, at Del Monte Beach, the Ocean Harbor House Condominiums are facing similar problems. The owners are seeking permits for a seawall structure. This is a close up of exposed support pilings. Some of the pilings appear to be dangling upon closer inspection.

October 18, 2007--Condo-owners received a permit to construct a sheet piling and rock seawall to protect their properties. Coastal Commission levied a 2.1 million dollar mitigation fee for this project. Swash was splashing on the wall and construction equipment.

June 21, 2008--Temporary rock seawall (above) is now being replaces with a permanent seawall. Condo owners may appeal the mitigation fee.

June 21, 2008--View toward Monterey past the Harbor House condominiums shows pinched bach during sea wall construction.

June 21, 2008--Exposed drainage pipe adjacent to the Harbor House Condos is a clear indication of approximate 0.5 m/yr coastal retreat experienced by this reach of coastline.

June 21, 2008--Very rare summer thunderstorm produced lightening strikes beyond Harbor House Condominiums. (Digital photograph with contrast and brightness adjusted to highlight lightening bolt)

Stillwell Hall shows the classic "Peninsula Effect" in this photo taken near the 2002/03 change. A once wide beach is now deep water in front of a sea wall. Note the rapid erosion that occurred between the previous photo (1998) and this one. Photo by Marc Edwards (USACE).

Same as above, showing northwest edge of Stillwell Hall. Note that the sea is getting behind the seawall; the seawall will become an island, then a reef, then will be buried in the continental shelf sands as the coast retreats. Photo by Marc Edwards (USACE).

10/31/2004 oblique aerial view shows that Stillwell Hall was dismantled and removed from the cliff top. The riprap seawall was also removed. Only the asphalt parking lot remains at this time.