Sloat Restoration through Managed Retreat

Sloat Restoration through Managed Retreat
This is our original vision for Sloat Restoration - graphic courtesy of PSA and Associates and the Ocean Beach Task Force

Our Vision of Beach Restoration and Preservation

The shorelines of Ocean Beach south of Sloat Blvd and Sharp Park in Pacifica are threatened by rip-rap seawallls and long-term erosion. This blog chronicles our campaign efforts to restore these beaches. Check out the web view of this site to see our proposed solutions and how to help- in the right hand column below. For all the latest about our efforts, see our monthly posts.

We advocate a managed retreat strategy to restore both Ocean Beach south of Sloat and Sharp Park.

At Sloat, our vision involves:

A long-term plan to relocate threatened infrastructure
(including the south of Sloat Great Highway, the two oceanside parking lots and the sewer lines underneath them).

The cleanup of all the rock and rubble littering the beach.

The use of sand dunes as the primary tool to slow erosion.

For Sharp Park, we advocate the decommissioning of the golf course, the removal of the rip-rap berm, and a full restoration of the wetland.

Monday, February 22, 2010

Some Good News as the Construction Continues

Photo by Les Martin

Greetings fellow Surfriders and Friends,

First off, the Surfrider Foundation San Francisco Chapter would like to thank all who came out and attended the Sloat fundraiser last Thursday at the Park Chalet. We raised well over a $1000 at the event which will help our efforts towards minimizing the scope and impact of the rock revetment as well as the development of a long term solution that protects the beach.

There is some good news to report on the construction project. The latest DPW planning document has the rock wall at about 400ft in length. This is less than half the size of the original proposal (900ft). Also, there is now a commitment from DPW to re-use a small amount of pre-existing debris to shore up certain sections that would otherwise have seen new boulders. Lastly, it looks like we have an agreement for DPW to remove at least 2000 tons of pre-existing construction debris. This is a positive development. We would like to thank and credit DPW for taking these measures to reduce the impact of project. We look forward to working together with this agency as well as other stakeholders at coming up with a long term plan. It won't be easy, but we do believe in a future at Sloat in which no additional rock is placed and a healthy, native beach profile is restored.

Bill McLaughlin, Erosion Committee

Friday, February 12, 2010

long-term solutions.

Bob Battalio is a big wave surfer and expert on the coastal processes at Ocean Beach. Bob has been working with SF Surfrider and Save the Waves to help educate the public and DPW on the best solution for the erosion at Sloat.

The following presentation was given by Bob at the Community Meeting at the Park Chalet a few weeks ago - it describes some of the history at Sloat and proposes a long-term design for the future (Slide 19). Slide 19 shows a drawing of what South of Sloat would look like with dune restoration and coastal retreat. Restoring the coastal dunes and condensing the Great Highway (two-lanes to one-lane) would allow for the beach to naturally retreat (but maybe not enough) along that section of the coastline - hopefully this would relieve some the coastal erosion problems.

We need a LONG-TERM erosion plan for OB and these are the type of design ideas that we would like to see proposed at OB - not rock walls and seawalls.

Thursday, February 11, 2010

Site Check 2/11/09 Construction Has Begun

Photo Credit: Les Martin

Fellow Surfriders and Friends,

I went down and did a site check last night. It's not good. DPW has created a dirt access ramp for their trucks, cranes, etc. and have begun placing huge boulders on the bluff. The idea of using sand bags has been dismissed. Re-using existing rubble seems also to have been ruled out. A completely new rock revetment is going up.

It’s a tragic scene – and it’s not just the new project going in. Due to the recent erosion, there is more construction debris unearthed down there than ever before. With this additional section of boulders, we have essentially a complete armoring of the entire area - a wall of concrete, rubble and stone stretching all the way from 1st lot to the bluff.

What you can do...

Please continue to write letters to all parties involved. There are many agencies with jurisdiction over this issue from the Mayor and the Board of Supervisors to the DPW, PUC and GGNRA. Tell them that the beach in the south of Sloat area is on the verge of extinction. The City needs to acknowledge this, and change course. At the very least, in the near term, we should specifically call for the removal of old concrete debris as mitigation, a pull back of the road and parking lots, and restoration of natural dunes in the area.

Bill McLaughlin

Thursday, February 4, 2010

sandbags on the beach.

As you know, SF Surfrider and Save the Waves were pushing for the use of sandbags (technically called sand-filled geotextile tubes/bags) along Ocean Beach at Sloat Blvd. over a rock revetment. Though the use of geotextile bags may be common on some sections of America's coastline (ex. Texas and North Carolina) they are not that common in California.

On Surfrider Foundation's website page Coastal A-Z geotextile tubes are defined as "elongated cloth bags or tubes made out of plastic material that can be stacked or arranged as a form of semi-hard coastal engineering." These sandbags are HUGE HUGE bags that are filled with sand and placed along a eroding coastline or in the wave zone to build up an offshore berm (reduces wave action).

"Hard" structures are riprap revetments (rock on beach) and seallwalls. "Soft" sturctures includes beach nourishment and coastal retreat. The geotextile tubes are known in the coastal management world to be in between "hard" and "soft" structures - which leaves the use of geotextile tubes in a grey area.

Bottom line is: (1) in some cases, Surfrider Foundation Chapters around the nation are against the use of geotextile bags because sometimes the bags are SO big and the casing is SO thick that the very very durable sand-filled sacks will never leave the beach system - and often the bags are placed in the water as a groin (see Florida Suncoast Chapter's website) or as an artificial reef; (2) there is not that much information out there about using the geotextile bags for shoreline erosion control (send us info if you have it); (3) i have always been told that the "sandbags" can have the same effects as seawalls etc (but this is probably because sometimes cement is added to the sand inside the sandbags and create "concrete bags"); and (4) however, one obvious positive side to the use of sandbags is if they are designed right, they can be easier to remove from the beach than rocks.


North Carolina Beach.

Southern California Beach.

(1) One of the ONLY articles on Geotextile Bags: Coastal erosion prevention by geotextile tube technology by E.Shin and Y.Oh
(2) Info on Coastal Armoring (not including geotextile bags):
(3) website for a geotextile company with good photos:
(4) Info on shoreline armorning (looks like North Carolina allows sandbags as a tempory fix):
(5) Info on alternatives to shoreline armoring:
(6) Info on the use of geotextile tubes in Texas (Texas considers geotextile tubes to be "hard" sturcturs):

Please let me know if you have any other good information on the use of sandbags on the beach for coastal protection.

If the bags were to be used along Ocean Beach, SF Surfrider would only support them for temporary fixes. A long-term solution to the erosion problems at Ocean Beach is what is essential.

Wednesday, February 3, 2010

Board of Supervisor's Meeting 2/2 and Next Steps

San Francisco Surfrider would like to thank all those who have written letters and attended recent public meetings to comment on the Sloat erosion issue. Well over 700 letters were sent and dozens of people showed up to comment. At yesterday's Board of Supervisors meeting, the emergency declaration was given final approval. Unfortunately, the rock revetment will be built. However, Surfrider and Save the Waves were able to forge a compromise plan with the DPW to limit the scope of their work, as well as to analyze the possibility of removing existing rock as mitigation (see Next Steps below for more detail). The great thing is that it was made very clear to our Supervisors that the addition of rocks is not seen as a positive solution to the problem. Nearly everyone mentioned the need to find a long term solution that does a better job at protecting the beach, not just the infrastructure. Thanks again to everyone who weighed in. We have gained excellent momentum going forward as we tackle this problem.

The Next Steps:

As the construction is about to begin, the chapter is actively working to ensure that the DPW limits the scope of the new rock revetment to only the most critical areas needed to protect the Lake Merced Wastewater Tunnel. Also, we aim to ensure that DPW does a serious analysis of possible re-purposing old rubble to add to the project (with a goal of a decrease in net new rock) and/or remove existing concrete rubble and quarry stone from other nearby areas as mitigation (a possible scenario of zero net new rock).

Meanwhile, work has begun toward developing a stakeholder’s group (gov. non-profits, general public) that will craft a long term solution to this vexing problem. Stay tuned for more details on this and other issues by checking in with this blog!

Bill McLaughlin
SF Surfrider Erosion Committee

Monday, February 1, 2010

BOS meeting on Tuesday Feb 2, Item NO. 35

Last week the SF Board of Supervisors (BOS) declared an emergency at Sloat for one week and required the SF Department of Public Works (DPW) to come back on the Feb 2nd BOS meeting.

During the last week, SF Surfrider, Save the Waves, Lara Trupelli from the Ocean Beach Vision Council, DPW, Army Corps of Engineers, several scientific experts, Supervisor Mirkarimi and others discussed alternatives to the proposed short-term solution of placing rock along 900-feet of shoreline at Sloat.

The environmental and scientific community that have been involved for over 10 years with the coastal erosion issues at OB were encouraging the use of "soft" solutions such as beach nourishment, retreat and sandbags (though sand bags fall somewhere in between soft and hard structures).

The severity of the emergency and the fact that the structure involved is a sewer pipeline, the City's DPW does not seem to have many other options, both politically and financially, than to place rock for this emergency. This is the result of unsatisfactory long-term planning. Now Ocean Beach will pay the consequences.

SF Surfrider still prefers, supports and recommends the use of sandbags, beach nourishment and retreat -- but if ROCK has to be used to address this emergency, than the following should be applied:

(1) absolute minimum amount of rock is placed - and only in the areas of critical need.

(2) SF Surfrider advocates that the scope of work be defined - limited to only protecting the Lake Merced Transport Tunnel, NOT the Great Highway or the parking lots.

(3) if rock has to be placed on the beach, than we call for MITIGATION work by removing an equivalent amount of old construction debris from OB at Sloat (the old concrete, brick and road chunks)

(4) finally, we call for re-establishment of a government/community
stakeholder group with the goal of developing a sensible long-term plan for the coastal erosion problems at OB. The plan should recognize sea level rise, include the goal of preserving the BEACH as a top priority, and avoid further waste of public funds.

(5) encourage the discussion of "coastal retreat," relocating structures out of the way of coastal erosion. For example, it may be possible to move the Lake Merced Sewer Transport Box from its current area by constructing a new facility farther inland

(6) the City of SF should work with the California Coastal Commission to assure that they are in compliance with prior emergency permits and to update the local coastal program (LCP) for City of SF

(7) Ocean Beach is our national park beach and all activities should be consistent with the National Park Sevice/GGNRA.

Board of Supervisors Meeting
Tues. Feb 2nd, 2PM
Item #35
Civic Center
San Francisco

Safety Reminder - Please stay off the bluffs

DPW has asked me to pass along a safety reminder. Please give the bluffs, even the areas that have not yet fallen into the ocean, a healthy safety distance. I just read the book Death in Yosemite which dedicates a chapter to people falling off cliffs; let's keep in mind our human ability to eyeball safety is fairly flawed.

Independent of your own personal safety is the stability of the bluff itself. Walking on, around, and underneath the bluff disturbs the soil directly, and potentially of greater importance, the paths in which runoff flows. The rain and waves are already challenging enough for the delicate bluffs without the additional disturbances.

Please stay off the bluffs.