Local
12:06 am
Thu May 17, 2012

Model Seawall

 

Crews are putting the finishing touches on a seawall project on Santa Cruz’s east side. The Pleasure Point seawall will serve as a model for future seawalls in California both for its innovation and community collaboration.

Looking out on some of Santa Cruz’s most sacred surf spots, coastal engineer John Kasunich points up the coastline to nearly 1500 feet of seawall. It stretches from 38th Avenue to Pleasure Point. It’s hard to see the wall until Kasunich knocks his hand on the hard wall. The seawall is camouflaged with the natural sand bluffs it was built to protect. Even the color matches – it’s darker at the bottom where high tides occasionally reach and lighter at the top. Kasunich was contracted by Santa Cruz County to be one of this seawall’s chief architects.  “I really do think we were one of the first guys in the state of California to actually use replica rock for seawall, rather than fantasy rock for Matterhorn at Disneyland,” Kasunich says. “This is about 20 years of evolution of that process for seawalls.”

That evolution is part aesthetic, part engineering. Kasunich explains that the replica rock is actually a concrete called shock-crete. The shock-crete is on top of a skeleton of steel rebar and plates bent to mimic the shape of the bluff. “And then we shoot the shock-crete, which is like – you pump it from the top with a fire hose, and you spray it on like a fireman shoots water,” he adds.  That creates a seawall that’s slimmer but just as sturdy as a traditional seawall.  Traditional seawalls are anchored in the ground and use bulk for stability. The Pleasure Point seawall is fastened with steel rods to the face of the bluff. Kasunich explains this provides an advantage if the ocean were to eat away at its base: “It just won’t slide down. So this wall could even get undermined, and it would hang in there.”

This seawall is the result of decades of debate about how to protect the houses on the cliffs, a nearby underground sewer line, and East Cliff Drive from the encroaching ocean. Concerns about what could happen on land if the wall wasn’t built also led to concerns about what could happen in the water if it was. “Surfrider in general is not in favor of coastal armoring,” says Jim Littlefield, a chapter officer with the Santa Cruz Surfrider Foundation. From the outset the Surfriders worried a seawall would fundamentally change the character of some of Santa Cruz’s most popular surf breaks.  “So what you see in front of the average seawall is a deepening of the water directly off the face of the sea wall,” Littlefield explains. “You’ve seen years where we’ve had one heavy storm after another? That’s the kind of thing that could, with the waves hitting the seawall and bouncing back, could gouge out that area and ruin the breaks that exist.” He acknowledges that the wall does include certain design elements that make it more surfer-friendly.  “We worked with the county agency to build in access points that weren’t in the original design, which is a safety item for people in the water, particularly under rough conditions,” says Littlefield. That includes goat paths that allow beachgoers to continue to access Pleasure Point even at high tide.

This kind of collaboration between government agencies and seawall opponents isn’t typical.  “I know the community of Santa Cruz got to the point where they had worked out most of those issues and they’d worked well with the various interest groups,” says Leslie Ewing, an engineer with the California Coastal Commission. “When it was recommended to us and brought before us a second time, it was fairly well supported by a variety of groups, which is unusual with seawall projects under almost every situation.” That’s why, in addition to being a model of cutting-edge engineering, Ewing says the Pleasure Point wall also set an example for how to engage communities in seawall projects.