2005 Storm Damage Protection Project Report

So I went through the 2005 Storm Damage Protection Project Report for the USACE and SF DPW (thanks to DPW for the posting it) and it gives a better overview of the shore protection problem up to 2005. I summarized a few of my favorite points: points that may shed light on 2010’s problem, but I encourage you to download the report and skim it yourself.

My Favorites Points:

The description of the different interests involved: pulling apart the road, from the lots, from the outfall pipe, from the Merced Transport pipe, from the bluffs. An outline of the interests on page 2-26 was originally by the SF Parks and Recreation Dept in 2002. The public discussion in 2010 often lumps all the interests together so it becomes difficult to weigh the cost/benefit and scope of different solutions.

Figure 3-3 on page 53 of the *.pdf shows a diagram of the most recent rip rap placement (referred to as Emergency Quarrystone Revetment) between first and second lots.

Moffatt and Nichol’s 1995 description of the coastal morphology starting on page 3-13. It indicates the the south lot area’s sand source is derived largely from the bluffs, and goes over seasonal reversals based on the wave climate.

Just like today: USACE (and other by CH2M Hill) 1996 study included the scenario where the lots were eroded and the Merced Transport box was threatened. The summary of this report is brief, but the area of the 1996 study appears to be further north in way of the lots, rather than just south of the outfall pipe where is 2010’s problem is. It gives a 22% chance of damage to the Merced Transport box, but it’s unclear if that is on a “per year” or “per storm” or what the relevant time scale is once the roadside has been reached. See page 3-16.

CH2M Hill reports that the southern reaches show large fluctuations in the area of the shoreline on page 3-25, and subsequent plots by Moffatt and Nichol show very large fluctuations of the shoreline of up to 100 to 150 feet.

Comic relief: When discussing constraints of different alternatives on 4-15, it notes that gorillas displays aggressive behavior during noisy earthwork. It’s tough to imagine a project with more exotic constraints.

Preferred alternatives are identified by each stakeholder on page 5-6. In 2005, as in 2010, the DPW prefers a hard structure over other alternatives for its lower maintenance cost.

Quoting from the discussion of acceptable alternatives on page 5-8, “SFPUC could not support any of the options that would result in the loss of the traffic lanes and possible exposure or loss of cover to the Lake Merced Transport facilities. The north bound traffic lane is important to the SFPUC as a means of access to the Oceanside WPCP. The northbound lane is also important in case of emergency in order to have two means of egress out of the WPCP facility. There is also concern that if the cover on the Lake Merced Transport is reduced there could be issues with structural stability or buoyancy effects.” The 2010 discussion has focused on the DPW’s interests; I’m curious as to why the PUC did not bring their interests to the public debate when the northbound lanes first closed. (Perhaps PUC is satified with the alternate routes onto Harding Rd and Armory Way and no longer considers Great Highway critical.) In 2005, DPW needed anything besides “no action.”

A stakeholder agency workshop held in 2005 gave all the agencies a chance to look at various alternatives. The DPW’s acceptable solutions listed on 5-12 include nearshore sand placement (which was the strategy adopted) and hard structures on the existing (then existing?) shoreline, presumablely for their lower maintenance cost. The SFPUC was willing to try anything that did not involve facilitated retreat or doing nothing. Each agency’s conclusions are summarized in a chart on 5-15.

New DPW Website

Our first post on this blog highlighted the many stake holders with overlapping jurisdiction at Ocean Beach. The San Francisco Department of Public Works is responsible for the roadway at Great Highway, and to some degree, the Lake Merced waste water pipe carrying untreated water into the treatment plant and the outflow pipe that carries the treated water 4.5 miles out to sea. (I’m looking into the split of authority between the SF PUC and the SF DPW on the pipes.) Consequently, DPW is most worried about its infrastructure, and is keeping the public informed with its new website here.

San Francisco Wastewater System Map, Source: SFwater.org

At the public meeting last night, most of the diagrams showed the amount of erosion relative to the previous state of the beach. Visibly, anyone could see how the road was threatened as the guard rail hangs from the bluff. What was not visible, however, is how the critical infrastructure of the Lake Merced Transport pipe and the Southwest Ocean Outflow pipe are threatened. All structures structures rely on the support of the surrounding soils, not just the road. I think in a public forum, unseen subterranean pipes never get as much attention as the roads under our feet.

The new DPW website notes that 70 feet of soil have eroded from the beach. This is a troubling number from the perspective of the beach, but is less indicative of the effect on the structures. I’d rather hear that the pipe requires X feet of soil on either side, and this margin has been compromised (or is threatened) for Y length of the pipe. Many of the members of the public at the meeting seemed to be surprised to hear about the Lake Merced Transport Pipe, and there were more than a few questions about it. I’ll stay in contact with the DPW communications department to see what additional information they can provide.

UPDATE: DPW has updated their presentation from Tuesday night and posted it here to give a bit more infomation on the pipe. The new page contains another report by the US Army Corps of Engineers that contains a good overview of the state of the beach in 2005. I'll read through the new USACE report and point out some of the interesinting parts.

Tell the BOS what you think!!! some of our thoughts....

Surfrider SF supports the following:

• As declared in 1999 resolutions, the use of hard structures as a short and/or long term solution to erosion should not be supported by the BOS. One possible option is to use sand-filled sacks or additional beach nourishment etc.

• We need a detailed risk assessment and cost analysis on moving the sewer pipeline, which was placed very close to the cliff edge in the first place.
  

• The DPW and SFPUC should evaluate long-term solutions like managed retreat and infrastructure relocation.
  

• A long-term plan for dealing with OB erosion needs to be in place (for Sloat and the ENTIRE OB).

• A new OB Taskforce or the OBVC needs to follow through and make sure the recommendations of the 1999-2005 OB Taskforce are met.

BOS today at 2PM.

Supervisor Chu adn Mirkarimi were both at last nights meeting and spoke out in support of finding a long-term solution for the coastal erosion problems and were in support of NOT using hard structures (like riprap rock or seawalls). As you can read below, these same issues came up ten years ago and the BOS passed resolutions that required the City of SF to address the coastal erosion and not use hard structures.

The BOS are meeting TODAY at the Civic Center in SF (as we speak) and will be reviewing the Sloat Resolution at 2PM (Item #53). It would be great to have people down there to support a resolution that restricts the use of hard structures (which is currently what the DPW is leaning towards) and encourages coming up with long-term solutions at Sloat.

You can watch the BOS meeting LIVE at:
http://www.sfgovtv.org/index.aspx?page=69

Sloat is Item # 53 and should be on around 2PM TODAY.

Also, you can email comments to:
oceanbeach@beachchalet.com

Community Meeting 1.25.09

Last night over 100 community members showed up to the Park Chalet to hear from the Department of Public Works and other experts about the coastal erosion issues and potential short-term and long-term solutions for the erosion at Sloat Blvd.

The meeting was introduced and run by Lara Trupelli, the owner of Park Chalet who also led the efforts of the 2000-2005 OB Taskforce and was appointed in 2007 by Mayor Gavin Newsom to be on the Ocean Beach Vision Council.

Frank Filice, the project manager from the Department of Public Works gave a short presentation on the proposed short-term solutions, which included three alternatives:

• Beach Nourishment - placing sand directly on the beach to restore the dunes (this alternatives was the most expensive but had the least environmental damage)
• Riprap Revetment - placing riprap (rocks) directly along the eroding shoreline to protect the road and sewer pipeline from the erosion (least expensive alternative with the most environmental damange). It was a little unclear how large of a structure they are proposing and how "temporary" the structure actually is.
• Sandbag Placement-placing large sand bags along the shoreline. This alternative was not described in details.

The DPW favored the placement of riprap because it was the most feasible based on cost and time. The DPW is proposing the short-term solution and will follow up with long-term solutions.

Bob Battalio, a big-wave surfer, an engineer and OB expert from Phil William and Associates (PWA) gave a presentation that described the efforts and recommendations of the 2000-2005 OB Taskforce. The OB Taskforce met from 2000-2005 as a result of a Board of Supervisor Resolution that was passed in 1999 in response to major erosion at Sloat (ummm....sound familiar?). The OB Taskforce determined that the best way to deal with the erosion was to set up a long-term plan with a focus on coastal retreat (moving the Great Highway more landward) and beach nourishment.

Dean LaTourette, the Executive Director of Save the Waves and Bill McLaughlin, an active member of the SF Chapter of the Surfrider Foundation spoke in support of the importance of a long-term plan that includes coastal retreat and beach nourishment. In addition, both environmental groups oppose the use of riprap (rock!!) to protect the road (not the beach) from erosion.

Peter Mull, the project manager for OB from the Army Corps of Engineers described the current efforts by the Army Corps of Engineers. Basically, sand that is dredged from the main ship channel annually has been placed in the waves at Sloat Blvd. The problem is that MORE sand needs to be placed and the sand should be placed directly on the beach. However, the dredging ship called the Essayons is not equipped to pump sand from the ship to the beach. At the moment, the Essayons can only dump sand in the waves.

Ross Mirkarimi and Carmen Chu, San Francisco Supervisors both spoke in support of a long-term solution and were generally against using hard structures.

The community was very engaged and, at times, confused and passionate about the issues and how to solve this coastal erosion problem. Questions generally focused on the long-term solutions - how can we get sand on the beach? Can we move the sewer pipeline? what will happen to traffic if the road is rerouted?

BUT as the meeting was coming to an end, the discussion was brought back to the short-term solutions. There was discussion on if the sand bag option could work - but it was clear this option has not been evaluated enough. Also, several folks were pushing to hold off the Board of Supervisor vote until next week so that more information on the alternatives could be explored.

At the moment, the Board of Supervisors are voting TODAY on a resolution that will officially declare the coastal erosion issues at Sloat an EMERGENCY - this will give the DPW the go-ahead to do what it takes to control the problem. It is important that the Board of Supervisors understands the importance of beach preservation in the decisions and remember that these SAME issues were brought up ten years ago. Past resolutions from 1999 did not allow hard structures (riprap/rock) to control erosion (even in an emergency) so why shouldn't we listen to what we said in the past!?

The Board of Supervisor meeting is at the Civic Center TODAY - be there at 2PM to comment on Item #53.

MORE INFORMATION:
BOS Meeting - http://www.sfbos.org/index.aspx?page=2314

Related Articles:
http://www.surfpulse.com/2010/01/summary-of-emergency-town-hall-on-sloat-erosion/

save sloat.

photo by sf surfrider

1.24.10

photo by sf surfrider

photo by sf surfrider

photo by sf surfrider

photo by k. riccitiello

photo by k. riccitiello

photo by k. riccitiello

photo by k. riccitiello