Just like there’s no such thing as a cure-all pill with no side effects, California is having trouble slowing the erosion of its towering cliffs without sacrificing meters of its beach space annually, although researchers are having trouble determining the exact degree of relationship between the two.

According to an article called “Rates and trends of coastal change in California and the regional behavior of the beach and cliff system” published in the Journal of Coastal Research, the man-made structures that are meant to protect the cliffs and bluffs along the Californian coast are deflecting waves back onto the sand and increasing erosion rates. The lesson: humans can't engineer our way out of everything.

The research showed that two-thirds of the state’s beaches are being eroded at a much faster pace.

Cheryl Hapke, a coastal geologist with the U.S. Geological Survey's Woods Hole Coastal and Marine Science Center in Massachusetts, listed harbors, ports, breakwaters, jetties and groins -- the structure not the body part -- as examples of man-made structures that “actually shut off the river of sand that naturally wants to move down the coast.”This river of sand would normally replenish the beaches with sand by moving sand from the top down to lower levels of the beach. But with the storm surge walls and other structures put in place to break the force of the waves, nature is being disrupted and the sand is unable to be pulled back down to the lower beach. As a result, the beaches are disappearing at an alarming rate.

The situation is somewhat analogous to the New Orleans fiasco, where the Mississippi River empties into the Gulf of Mexico. Due to excessive damming along the river for flood protection and other human changes to the river, silt is unable to be naturally deposited at the river's mouth. As a result, land eroded by the ocean is not being replaced, and hasn't been for decades. This is one reason New Orleans is sinking and subject to excessive flooding, as we all witnessed following Hurricane Katrina.

A few of the beaches being affected by engineering in California include San Onofre Beach, which is eroding at an average rate of close to two meters per year; Torrey Pines City Beach, which is eroding at a rate of 2.2 meters per year; and Del Mar City Beach and Mission Beach in San Diego, both of which are disappearing a rate of more than 3.5 meters per year. (Some beaches, such as those near Oceanside Harbor, are actually growing because the structures there are catching the sand that is deflected down the coast.)

Cliff and buff erosion is certainly slower, owing in part to the man-made structures continually reinforced particularly in Southern California, but the state is still having trouble with it. The city of Carlsbad just approved the construction of a $500,000 wall, colored and textured to match the natural rock face, following a partial bluff collapse at a popular surfing spot in December. The California Coastal Commission wants to expand a recreational pier at Goleta Beach to protect the park. Local chapters of the Surfrider’s Foundation are opposing both moves on the grounds that further action would interfere with natural cycles. Other environmental groups are also pushing for what the groups call “managed retreat,” which would mean leaving the beaches alone completely for Mother Nature to take her course and moving back shoreline homes being protected by man-made structures. 

The study is significant because it illustrates trends around the coastal U.S. Trying to muscle nature is most often not only a losing battle, but one which may cause unpredictable outcomes, and costly ones at that. Rather throwing money at the ocean, policy makers and scientists at the state and federal level need to institute smarter policies for dealing with two unfortunate realities: (1) the seas are rising, and (2) they will continue to encroach on the land at the rate of up to 50 inches horizontally for every one vertical inch the sea rises. Over the past 100 years, the ocean rose between 4-10 inches. As global temperatures rise and the oceans expand, this trend will continue for the next 100 years, exacerbating the problem of coastal erosion and flooding. With over 95,000 miles of coastline and 53% of the U.S. population living on or within 20 miles of the coast, this problem is massive in scale.