To Protect or Relocate the Lake Merced Tunnel...

The costs of rejecting managed retreat at Sloat just keep piling up.

Greetings Surfriders,

While we wait for the next public meeting for the Local Coastal Program revision for Ocean Beach, we would like to take this time to share with you more details regarding our position on the Lake Merced Tunnel (LMT).

Let's start with our main argument for a cost/benefit analysis.

The Ocean Beach Master Plan advocates that we spend nearly $100 million to protect the LMT where it is, right on the beach (http://www.spur.org/ocean-beach see VII-5 (pp. 154-155). Surfrider has suggested that we look into a plan to relocate the structure. Our reasoning is simple: Why leave such vital and sensitive infrastructure in an erosion hazard zone? By moving the LMT well inland, it can be safeguarded from erosion for a much longer time.  We would also gain a much better restoration project for the beach.

Cost:  Unfortunately, our city has cited cost before in rejecting managed retreat for Sloat. Back in 2005, the Ocean Beach Task Force, like the OBMP, recommended a managed retreat plan for the erosion. The Task Force proposal? Pull back the road and parking lots from the shoreline, and use sand dunes, not rock, to slow erosion. There is graphic of this proposal on the top right corner of the blog.

SFDPW rejected that proposal, stating that the high cost of managed retreat made the idea "infeasible."  It was never explained by the agency why and how it made this determination. Did SFDPW not have the funds or simply did not wish to spend / seek the funds for the project?

What we do know for sure is that in the ensuing years, at least $10 million was spent by the City on dumping more rock on the beach south of Sloat, repairing the Great Highway as it fell onto the beach and more enacting sand back-passing projects.  The two recent sand dunes (2012 and 2014) have just washed away.   Additionally,  significant taxpayer money was spent by the Army Corps of Engineers in their failed effort to replenish Sloat with dredge spoils.

What do know on the cost issue is that the City has a "planning level" cost estimate of an LMT relocation alternative.  A 2010 letter to the Coastal Commission cites LMT relocation at approximately $110 million.  The current Master Plan seawall is estimated to cost approximately $90 million. (Source See Page 11).  Based on these figures, there is probably not a huge difference in cost between these two options.  We do assert that, if done right, relocating the LMT will bring greater long term benefits both in regards to safeguarding the structure and preserving the beach.

It is time we had a full cost-benefit analysis between the two alternatives. It could turn out that relocating the LMT is not just good for the beach and the safety of the infrastructure; it could also be the superior economic option.

Thanks for staying engaged!