Relocating the Lake Merced Tunnel could be well worth the trouble. The high tide line shown here will continue its march inland as the years go by.Photo: B. McLaughlin
Greetings Surfriders and Friends,
In our last two posts, we laid out the two core arguments in support of a study to relocate the Lake Merced Tunnel (LMT). This month, we would like to address the Ocean Beach Master Plan's support of keeping the LMT on the beach.
In section III-24 of the Ocean Beach Master Plan "Why Not Relocate the Lake Merced Tunnel Today," a series of arguments are made against a managed retreat plan for the Lake Merced Tunnel. They are summarized below, followed by our response:
Opportunity to Protect in Place
SPUR claims that the Lake Merced Tunnel can be protected in place (with the beach condition dramatically improved) for the next several decades. This is characterized as a "win-win" approach for both infrastructure and environment/recreation. Surfrider believes a strategic relocation of the tunnel would secure this asset for much longer. If built with the future in mind, a LMT relocation could protect it for the rest of its lifespan. Certainly, opening up more shoreline for restoration is better for recreation and the ecosystem. It also could be a much more cost effective way to preserve the beach as more beach area would reduce the need for sand replenishment.
Environmental And Regulatory Challenges
Spur argues that relocating the Tunnel would bring significant regulatory complexities. The suggestion seems to be that such changes would be burdensome. Given everything that is at stake, we believe such an effort would be worthwhile.
SPUR cites the high cost of re-configuring the structure. Please see our June post. The cost of relocating the Tunnel does not appear to be drastically higher than building a protective seawall.
The OBMP states: "Relocating the Lake Merced Tunnel would allow the coastline to recede naturally through erosion, but only a short distance, as other structures, including the existing force mains and pump station, the Fleishhaker Pool building and the Oceanside Treatment Plant, lie immediately behind the tunnel, limiting the benefits of relocation or necessitating the relocation of additional elements relatively soon." While it is true that the beach area left in front of the Oceanside Treatment Plant and Pumpstation/Force mains is short, the amount of shoreline that may need hard "back-up" protection is quite small compared to the entire shoreline area that would be needed to protect the Lake Merced Tunnel. With sea level rise estimates and erosion projections continuing to rise, the LMT relocation issue could be a brilliant opportunity for SFPUC to begin mapping the future of other pieces of threatened infrastructure, not just the Lake Merced Tunnel.
SPUR argues that SFPUC has many responsibilities around town that may take precedence over relocating the Lake Merced Tunnel. We believe that an erosion threat to a wastewater plant's key infrastructure is quite serious. As surfers, we understand the power of the ocean, It is unpredictable and destructive force should never be underestimated. The Sloat erosion challenge should command top level priority and resources.
Thanks for staying engaged with us!