The Incredible Shrinking Shoreline

Today’s and Friday’s 7-foot high tide, combined with a severely eroded shoreline, threatens homes in Surfside. The problem stems from an arrowhead- shaped jetty constructed at the mouth of Anaheim Bay in the mid- 1940s. Since the jetty was built, Surfside has suffered continuous shoreline depletion. A look at the problem and some solutions:

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Swell Life

Surf hits Orange County beaches from two directions, west and south. In both cases, so- called “incident waves” hit the jetty, creating reflective waves that flow counter to natural wave movement, taking sand away from Surfside.

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Southern

Typical summer swells travel up coast from warm tropical waters off Mexico.

1. Incident waves strike jetty from southwest.

2. Waves reflect off jetty, striking shore form northwest and carrying sand south.

3. Sand carried south meets sand naturally flowing north, creating transitory sand deposit.

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Northern

Fall and winter swells originate in the Bering Sea off Alaska but strike beach from the west.

1. Incident waves strike jetty from west.

2. Waves scour sand from shore, moving it south.

3. Sand built into deposit as incident and reflective waves prevent southward movement.

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Two Solutions

Scenarios for slowing Surfside’s sand erosion focus on reducing the effect of reflective waves by changing where they break. Both plans are currently under consideration.

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Stub Breakwater

A 1,200- foot stub would diminish waves or redirect reflective waves to prevent sand from being carried south.

1. In southern swell, reflective waves created by shore break are held at base of jetty.

2. In northern swell, waves break over spur diminishing wave energy.

Problem: Does not completely prevent wave reflection.

Estimated cost: $5 million.

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Surf Reef

Constructing 1,200- foot artificial breakwater would diminish power of waves reaching beach and hitting jetty.

1. Waves break over reef creating riding path for surfers and removing reflective wave effect.

2. Trench in front of reef diminishes wave energy.

3. Mild surf washes onto Surfside beach.

Problem: City and county could be subject to liability suits from injured surfers.

Estimated cost: $4 million.

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Surfside Beach Erosion

Since the mid- 1940s, when the jetty was constructed at the entrance to Anaheim Bay, beach erosion at Surfside has been a problem.

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Comments

Year: 1950: Houses threatened but not damaged.

Year: 1955: Houses damaged.

Year: 1959: Houses damaged.

Year: 1962: Houses damaged.

Year: 1964: 4 million cubic yards of sand added.

Year: 1970: 2.3 million cubic yards of sand added.

Year: 1979: 1.6 million cubic yards of sand added.

Year: 1981: Residents install emergency revetment.

Year: 1983: Severe winter storms cause immense shoreline erosion.

Year: 1985: 800,000 cubic yards of sand added.

Year: 1990: 1.8 million cubic yards of sand added.

Year: 1995: Residents install emergency revetments as erosion threatens houses.

Beach depth *

* Distance from Corps of Engineers baseline measurement (200 feet east of beachfront homes)

Sources: Moffatt & Nichol Engineers, Army Corps of Engineers, Times reports, city of Huntington Beach, Orange County Harbors, Beaches and Parks; Researched by APRIL JACKSON / Los Angeles Times