Saturday, March 15, 2014

Status of The 2012 Sand Berm

Has the 2012 sand drop helped add more beach area to Sloat?

Whatever the reason, there has been a noticeable increase in sandy beach 
at the first parking lot. This is good news. 

Greetings Surfriders and Friends,

If you haven't yet signed our online petition, please do so today! http://action.surfrider.org/p/dia/action3/common/public/?action_KEY=9198

RE: New Erosion Hotspot at the 2nd Parking Lot: We are still awaiting a meeting with the National Park Service to discuss what can be done.  The good news is that it appears that the erosion may have stabilized at the manhole cover.  We have gotten word from SPUR that a plan to re-align the parking is under development.

This month we would like to provide an update on the status of the sand drop that was completed during the summer of 2012.  It looks like most of the sand has already eroded. At the same time, there has been an improvement of the beach width in the immediate area.  Whether that improvement came from the sand berm is uncertain at this point. As we have reported before, the beach can expand and contract at different locations depending on a myriad of factors.  Check out the links to the side of this page for key sand transport studies done by the USGS and others.

Ocean Beach sand transport is a complex system which is still largely unknown. The key facts we do know can be summarized this way.

1. The amount of sand piling up outside the mouth of the Bay has been shrinking ever since we damned the rivers, channeled the delta, filled in and mined sand from the bay.

2. The entire beach  generally erodes under the barrage of winter swells, and accretes (or rebuilds) during calmer spring and summer conditions.

3.  Presently, there is one predominant northbound and one southbound sand transport current at Ocean Beach.  The dividing line is Noriega where northbound currents transport sand where it tends to accrete or build up the shoreline at VFWs and Kellys.  Meanwhile, southbound currents (also from Noriega) generally act to scour sand away from the beach all the way down to Sloat.

SPUR is leading a group of engineers that are studying the effects of the 2012 sand drop. We hope to have an official update on this and other sand management issues sometime this spring or summer.  That would include a plan to keep the sand from blowing into the parking lot.

Thanks for checking in!
North Lot December 2011 - Pre-Sand Drop
North Lot Summer 2012 (sand drop complete)
North Lot March 2014  Much of the sand has eroded. However, safe access remains.