The Huge Boulders Along the Santa Cruz Shoreline: A Common Coastal Story

A view from the mountains to the eroding coast along West Cliff Drive in 2010. Picture © Kenneth and Gabrielle Adelman, California Coastal Records Project www.Californiacoastline.org.
A view from the mountains to the eroding coast along West Cliff Drive in 2010. Picture © Kenneth and Gabrielle Adelman,
California Coastal Records Project www.Californiacoastline.org.

If you live along or visit the west coast of California you have likely seen various types of structures designed to stop the coastline from eroding. Two common ways to decrease erosion are to place rip-rap (1– to 2–ton boulders boulders) along the cliff edges and to construct concrete sea walls. In recent decades, these methods of protecting or “armoring” the coast are so pervasive that people might not even notice them. I live near West Cliff Drive in Santa Cruz, California, and I am often amazed that people strolling along this beautiful section of the coast don’t even realize that rip-rap is not a natural feature.

The Cliff House along West Cliff Drive, Santa Cruz, California in a 1950s era postcard. Image courtesy of Frank Perry.
The Cliff House along West Cliff Drive, Santa Cruz, California on a 1950s era postcard. Image courtesy of Frank Perry.
The Cliff House in 2012 from the same vantage point as the postcard.
The Cliff House in 2012 from the same vantage point as the postcard. Rip-rap now fills both beach coves.

Development and Storms

Much of the development along the California Coast, including Santa Cruz, took place between the mid-1940s and the mid-1970sa three decades-long period of below-average rainfall and storm frequency. In the late 1970s the stable weather period began to change with large storms in 1977–78 and 1982–83. These storms led to increased studies of trends in ocean and atmospheric circulation.

ENSO Cycles

These studies found that changes in atmospheric pressure, wind patterns, and ocean circulation in the equatorial Pacific create cycles known as the El Niño/La Niña Southern Oscillation (ENSO). El Niño conditions create more severe weather with above average rainfall and more frequent coastal storms. In contrast, La Niña conditions create mild weather with below normal rainfall and storm frequency. Seventy five percent of the storms that have been particularly damaging between 1910 and 1995 occurred during El Niño events.

A crane placing rip-rap near Steamer Lane in 1981. Photo courtesy of and © Frank Perry.
A crane placing rip-rap near Steamer Lane in 1981. Photo courtesy of and © Frank Perry.

The El Niño of 1982–83

The El Niño storms of 1982–83 did more damage than any winter since. That winter, eight major storms hit the California coast and were particularly damaging for several reasons. First, sea levels were already elevated by the warmer El Niño conditions; second, many of the storms hit at the peak in spring high tides (thus they scoured away more sand and reached higher and further onshore); and third, the swells came not from the northwest as is typical but from the west (where the waves struck the coast dead on with no energy loss from refraction) and southwest (directing energy to areas that are typically more sheltered). Thirty three ocean-front homes were destroyed and over 3,000 homes and businesses were damaged.

The Armoring of West Cliff

The first rip-rap on West Cliff Drive was installed in the mid-1960s. However, most of the armoring there today was installed in the 1980s and early 1990s, which was a period with several strong El Niño events.

Armoring also impacts coastal ecology by covering beach habitat used by birds and fish, algae, and invertebrates. For example, birds need protected rocks along the coast to roost and breed. Because armoring prevents the formation of new peninsulas, arches, and sea stacks in favor of a smooth armored coast, this habitat will get even more scarce.

This cliff is part of the peninsula that forms "Lighthouse Point". It provides great resting places for these Brandt's cormorants.
This cliff is part of the peninsula that forms Lighthouse Point. It provides great resting places for these Brandt’s cormorants.

The Coastal Commission

The California Coastal Commission was created by the voters of California in 1976 and regulates development along the coast. Under their regulations new armor is only allowed to protect existing structures that are threatened. New development must be set back far enough to avoid being threatened by erosion for its projected lifespan. However, these regulations are sometimes evaded due to ambiguous language and politics.

Adding sand to beaches, which can increase beach width and decrease erosion has been tried and considered as a long-term mitigation strategy. But the financial costs are huge and the effectiveness variable and often only short-term, especially in California where sand moves southward along the coast at high rates (a process known as littoral drift).

The Future of the Coast

Eighty six percent of California’s coast is eroding. A rising sea level and more severe and perhaps more frequent storms from human-induced climate change will only exacerbate coastal erosion. From the perspective of a homeowner on West Cliff Drive, or on any part of the California Coast, protection from wave erosion is important. However, it comes at a high cost. Millions of dollars of federal, state, and private money are spent every year on coastal armoring.

A sea wall and rip-rap along West Cliff Drive, Santa Cruz, California, 2011.
A sea wall and rip-rap along West Cliff Drive, Santa Cruz, California, 2011.

What do you think about the varying trade-offs to homeowners, the public, animals, and the environment? Should new development along the coast be allowed? Should existing structures be allowed to protect themselves indefinitely—and at whose cost? In some cases structures have been torn down or moved. The coastline is retreating landward, and this trend will continue and probably accelerate.

Rip-rap filling the beach between San Jose and Stockton Avenues along West Cliff Drive, Santa Cruz, California. Photo by Archer Koch of MultiRotorCam.
Rip-rap filling the beach between San Jose and Stockton Avenues along West Cliff Drive, Santa Cruz, California. Photo: Archer Koch of MultiRotorCam.

Take the Self-Guided Mobile Tour

This piece is part of the West Cliff Drive Tour. Download the free app with many tours of the Santa Cruz area and beyond.

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  1. Sources



About The Author

I really enjoy field trips. I love being in a cool place and having someone tell me about it. The problem is, you can’t always find a professor or park ranger-type to tell you all they know about the local rocks, plants, and history. So I decided to combine my love of things natural with mobile technology.

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5 Comments

  1. Waddell

    My question is, who makes the decision to put in all these rocks? What these rocks do is protect the millionaires, who foolishly built or bought a house across the street from the ocean. In trade, what has happened,all the little coves, peninsulas,beaches and surf spots have been ruined! I was on westcliff today and saw that they were putting in MORE boulders near the end of Woodrow, which will completely destroy the surf spot “finger bowl” once and for all! Finger Bowl was a natural phenomenon that occurred every summer until the early 90’s “when they put the boulders in”. Back to my original question….who makes the decision? Why is there no vote from the people that live here.

    Reply
    1. Ranger Gaudinski

      Hi Waddell. I understand this sentiment. These decisions are made by the county and city planning commissions and the Coastal Commission has I believe final authority. To find out when these bodies have meetings for landuse related issues check out Gary Patton’s morning Land Use Report on KUSP: http://blogs.kusp.org/landuse/ which with their new programming may just be a podcast. You can also contact your County Supervisor (Ryan Coonerty for Santa Cruz/West Cliff Drive) and City Council members and ask them.

      Reply

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