Sculpted Shotcrete Facings on Solana Beach Seawalls: A Briefing

Briefing summary

• Solana Beach’s coastal rules require bluff retention devices to resemble the natural color, texture and form of the adjacent bluffs. On most seawalls, that requirement is met with a sculpted, colored shotcrete face.
• The facing is not one thing. Depending on the device, it may sit on erodible concrete meant to wear back with the bluff, on a reinforced tied-back wall, or on a taller wall that encapsulates the bluff’s clean sand lens.
• The City’s Land Use Plan calls for annual visual inspection and maintenance as needed. Facing damage is often the first visible sign that something behind it deserves a closer look.
• Facing repair can be routine or can need a coastal permit, depending on materials, equipment and scope. That determination rests with the agencies, not with the owner or the contractor.

The rule behind the rock-like finish

The City’s Local Coastal Program Land Use Plan (LUP), Chapter 4, sets design standards for coastal structures. Under Policy 4.49, a coastal structure is to be “constructed to resemble as closely as possible the natural color, texture and form of the adjacent bluffs,” and “landscaped, contoured, maintained and repaired to blend in with the existing environment.”

The Municipal Code says much the same. SBMC Chapter 17.62 defines “natural surface and texture” as a surface that “resembles as closely as possible the existing color, texture and contour of the adjacent coastal bluffs.” One of the findings for a shoreline defense structure is that it be constructed and maintained with an earth-like appearance resembling the natural color and texture of the bluffs. The same chapter, adopted by a 1994 ordinance, also defines a “gunite covering” as a mixture of cement, sand and water usually sprayed over a mold. Sprayed concrete has been part of the local rulebook for decades.

The practical result is a facing that is shaped and colored so that, from the sand, it reads as layered rock rather than a flat gray wall.

What sits behind the facing

LUP Appendix B shows the City’s preferred bluff retention solutions, approved by the Coastal Commission in January 2014. The figures label the faces “textured/colored shotcrete” or “textured shotcrete wall,” and each note block says the bluff face is to have natural color and texture. What changes is the structure behind:

1. Seacave or notch infill (Figure 1A). Chapter 4 describes this as not a structural wall: not reinforced, no tiebacks, and built only of erodible concrete meant to erode at the same rate as the surrounding bluff. The infill must keep a textured and colored face mimicking the bluff.
2. Infill with a concrete facing, or a lower seawall (Figures 1B and 1C). Erodible infill with a higher-strength concrete face on its seaward side, or a reinforced structural wall with tiebacks into the sandstone. Either way, a textured face is required.
3. Higher seawall encapsulating the clean sand lens (Figure 2). A structurally engineered wall with tiebacks, about 35 feet high per the LUP, again with a textured face.
4. Seawall and upper bluff repair (Figure 3). The lower wall is textured to simulate the bluff, and the upper slope is rebuilt with geogrid-reinforced soil and planted.

For a board, the point is this: two walls can look alike from the beach and be completely different structures. The facing on an erodible infill is part of a system designed to wear back. The facing on a tied-back wall is a skin over a reinforced structure. Damage means different things on each.

Common facing conditions

What an annual walk-down tends to find, in rough order of seriousness:

1. Color fade and staining. Sun, salt and runoff change the finish over time. Mostly an appearance item, though the LUP standards make appearance part of compliance.
2. Surface crazing and fine cracks. Normal for sprayed concrete. Worth mapping so growth can be tracked year to year.
3. Delamination. A hollow sound when tapped, or a section of facing pulling away. Water and salt can then get behind it.
4. Spalling with rust staining. On reinforced walls, rust streaks or popped concrete can mean corrosion of steel behind the face. Our salt-air spalling page covers the mechanism.
5. Damaged tieback covers or exposed anchor heads. On tied-back walls, these deserve prompt attention because they protect parts of the structural system. Our post on how tiebacks hold a seawall explains what sits under those covers.
6. Gaps at the wall’s edges or base. Separation where the facing meets the natural bluff, or scour at the toe, points to movement or wave attack rather than surface wear.

Maintenance under the LUP

Policy 4.45 lists the goals for preferred bluff retention solutions. One of them is to “conduct annual visual inspection and maintenance as needed.” The same policy says the bluff property owner’s licensed civil or geotechnical engineer must examine the device for its specific location and take responsibility as the Engineer of Record. Appendix B’s notes also call for monitoring for future maintenance and, on the structural options, a detailed methodology for monitoring and maintenance over the life of the device, with maintenance that would push the device farther seaward kept to a minimum.

For existing devices that predate the preferred solutions, Policy 4.60 allows repair and maintenance to the extent the work conforms to the LCP, “including the structural or aesthetic requirements.”

When facing work needs a permit

Coastal Commission regulations (14 CCR 13252) list repair and maintenance methods on seawalls, revetments and bluff retaining walls that require a coastal development permit. They include substantial alteration of the foundation of the protective work, placing solid materials on a beach or on the shoreline work, replacing 20 percent or more of the materials with materials of a different kind, and having mechanized equipment or construction materials on sand, a bluff, or within 20 feet of coastal waters.

Facing repair on a Solana Beach seawall almost always involves materials and equipment on or near the sand. The LUP also requires shotcrete and concrete to be contained with tarps or similar barriers that fully enclose the application area during bluff work. Whether a particular repair needs a permit, and which one, is decided by the City and the Commission. Plan the conversation early.

Six steps for the association file

1. Keep the original approvals and as-builts with the reserve file. They tell you which kind of device you have.
2. Walk the face once a year at a low tide, with photos from fixed points.
3. Separate appearance items from structural signals in your notes.
4. Treat rust staining, delamination over steel and damaged tieback covers as structural items.
5. Ask your Engineer of Record whether a facing repair could touch anything behind it.
6. Raise permit questions with the City before scheduling crews.

Where we fit

We work with owners and associations to document facing condition, separate surface wear from structural signs, and organize the record for the Engineer of Record and the agencies. We coordinate with licensed engineers as needed; design responsibility for the device stays with the owner’s engineer, as the LUP requires. Scope for facing work usually turns on access at the beach, tide windows, how much facing is involved, whether steel or tiebacks are affected, and what review the work triggers. Our seawall and upper-bluff repair page covers the wider system.

We serve the whole city of Solana Beach. To have a seawall face documented before the winter swell season, request a Free Quote. Our companion briefing on drainage for Solana Beach lots covers the water side of the bluff-top story.