Saturday, January 26, 2013

Sloat Beach Fill Time Comparison - Fall 2012 to Spring 2013

<Updated March 16, 2013>

In the summer/fall 2012, the National Park Service and City of San Francisco implemented a sand management project at Ocean Beach, which moved excess sand from north Ocean Beach and placed it along an eroding section of beach/bluff at Sloat Boulevard.

The project was completed in September 2012 and resulted in the placement of approximately 100,000 to 150,000 cubic yards of sand in front of the parking area at Sloat.

I've visited the area several times over the past few months and have taken photos to document the evolution of the sand fill.  Since October, a significant portion of the sand has been eroded due to high waves during the late fall and early winter months.  The most significant retreat appears to have occurred at the south end of the parking lot, in the vicinity of the sand bag to revetment transition.

I first noticed exposure of the sand bags in November 2012.  My visit in January 2013 was the first time I had observed exposed rock, which must have been exposed sometime over the past month. Upon my return in March 2013, it appeared that additional sand had been placed over the sandbag embankment at the south end of nourishment area.

While the sand has been actively eroding, the good news is that it has temporarily prevented the need to place additional rock on the beach under emergency conditions, which has been the standard operating procedure over the past few years.

Read more about the project here and on the NPS project page.

Here's a video of some of the erosion processes at work, from November 2013:



October 2012 to January 2013 to February 2013 to March 2013. View looking south at Sloat Blvd parking lot.



October 2012 to December 2012 to January 2013 to February 2013 to March 2013. View looking north from south end of Sloat parking lot.



October 2012 to February 2013. View looking north at Sloat parking lot.

 January 2013 to February 2013. View looking north towards Sloat parking lot.



October 2012 to February 2013 to March 2013. View looking north at Sloat parking lot.


December 2012 to January 2013 to February 2013 to March 2013. View at south end of parking lot. Sandbag to revetment transition.


October 2012 to December 2012 to January 2013 to February 2013 to March 2013.  View looking south along beach.



October 2012 to December 2012 to January 2013 to February 2013.  View looking north along beach.

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