Surfline's Long Beach Breakwater Surf Report
Produced for the Surfrider Foundation
and the Long Beach Surfrider Chapter
-- By Sean Collins / Surfline

IS IT TRUE THAT LONG BEACH USED TO HAVE GREAT SURF BEFORE THE BREAKWATER, AND THAT THERE IS SERIOUS CONSIDERATION TO STUDY THE REMOVAL OF THAT BREAKWATER TO IMPROVE THE SURF AND WATER QUALITY IN LONG BEACH?

Yes...

INTRO: This report was requested by the Surfrider Foundation to add to a feasibility study ordered by the City of Long Beach studying the possible removal of the Long Beach Breakwater, and the associated effects of the increased surf and resulting surfer visits to Long Beach. This report will cover the following topics:

• PART 1 - The wave and surf climate of the Long Beach/North Orange County area and how these waves will be affected by local conditions such as offshore island wave shadowing and refraction over underwater bathymetry.


• PART 2 - How would the surf be in Long Beach if there wasn't a breakwater? Analysis and swell modeling of the nearshore wave climate without the Long Beach Breakwater and comparison to large waves at Seal Beach. Did you know that on a strong South swell Long Beach would have larger waves than Trestles?


• PART 3 - If Long Beach had good surf, would more surfers and beachgoers visit? A analysis of Long Beach's potential annual surfing conditions and surfer visits after removal of the Long Beach Breakwater. More than five (5) years of Surfline daily observed surf reports were analyzed for nearby popular surfing areas in Seal Beach and South Bolsa Chica Beach to develop a comparative baseline.

PART 1 - NORTH ORANGE COUNTY, SEAL BEACH, LONG BEACH WAVE CLIMATE - The wave climate for the Long Beach/North Orange County area is extremely complicated as there are numerous variables and obstacles that need to be considered. Due to our ever present marine layer and haze, we often forget that there are a number of very large islands within 20-50 miles offshore that typically do a very good job of blocking 50-100% of the swell and wave action headed to the Long Beach/North Orange County area.

Additionally, Point Conception and the Palos Verdes peninsula to the northwest block a great amount of swell. But there are swell windows where significant swell can pass through and reach our local beaches depending on the swell direction.

SWELL WINDOWS - The Surfline North Orange County/Long Beach swell window chart below displays open swell windows to the straight west (250-280 degrees) and from the south (160-185 degrees). All swells that arrive in Long Beach will pass through these windows, unless there happens to be a local storm just a few miles offshore inside of the islands.



After identifying the local swell windows and shadows caused by the offshore islands, we can also locate the specific regions throughout the Pacific Ocean from where storms can send swells to Long Beach. The sources of swell for Long Beach will be from:

1. The North Pacific when storms drop very far down to the south to obtain the straight westerly swell direction needed to pass through the west swell window.


2. Local wind-swell from strong winds inside of the offshore islands - approaching from the west through the east/southeast.


3. South swells from hurricanes off Baja California, and strong long period south swells from intense storms down in the Southern Hemisphere 3,000 to 7,000 miles away.

The Offshore Islands Shadow regions in the chart below identify areas from where all swell will be blocked by Point Conception and the offshore islands off the California coast.



Special note: "Swell Period" is a term that will be used throughout this report, and is defined as the time in seconds between successive waves as they pass a stationary point. Swell periods of waves may vary greatly, but stronger wind speeds in a storm, blowing for longer durations, and blowing over greater distances of ocean, will transfer more and more energy into the ocean, resulting in greater wave heights and longer swell periods.

Longer period swells extend wave energy deeper below the ocean surface. A long period swell of 20 seconds has energy extending 1,000 feet deep; while a shorter period swell of 12 seconds has energy extending only about 300 feet deep. As such, longer period swells can be greatly magnified and enhanced by the ocean floor, often resulting in much greater surf heights in some areas compared to others depending on the offshore bathymetry. This is a very important factor in determining the surf for Long Beach.

The Surfline Wave Model graphic below displays the Southern California swell windows and blocked island shadows. Wave sizes along the coast will change depending on the swell direction. Also notice how the swell energy along the coast focuses differently between the 18 second period and the 12 second period - even though the swell direction is exactly the same. The longer 18 second period swell energy extends deeper below the ocean surface so it is more greatly focused by the underwater bathymetry contours of the ocean floor. The color legend indicates how much the swell height has changed from the original offshore swell height "yellow". Notice the "RED" wave heights near Seal Beach for South-180, 18-Seconds.



LOCAL BATHYMETRY - A huge factor to consider for the Long Beach/North Orange County region is the how the local bathymetry (the shape and topography of the ocean floor) in the San Pedro Channel can greatly enhance the wave heights nearshore. Geologically, millions and millions of years of sediment flowing out of the Los Angeles and San Gabriel rivers have built up and created the shallow water San Pedro Shelf that extends 10 miles offshore from Long Beach.



The San Pedro Shelf acts like a magnifying lens that grabs the deep long period swell energy and compresses/compounds it into much larger, increased wave height nearshore. This process is called refraction, where waves will naturally turn and focus toward shallower water. The San Pedro Shelf extends 10 miles offshore, and the unique bathymetry at the 100-600 foot depth 5-10 miles offshore greatly affects the longer period swell periods over 16 seconds.

Additionally, longer period south swells approach the shelf at a perfect angle so they are magnified the most. West swells with longer periods are also magnified by the shelf but to a lesser extent, and most of that extra west swell wave energy is focused farther south in Surfside and Huntington.

Another side effect of the San Pedro Shelf refracting long period south swells from the Southern Hemisphere was intermittent harbor seiching around the Pier J area in the Port of Long Beach and the US Navy Shipyard. Very long period, surging tidal pushes inside the harbor would slowly slosh around like in a bathtub, which would damage the ships tied up to the piers and stall the loading and unloading of containers.

During the mid 80's we participated with the US Navy in a study to research this problem, and we clearly concluded that the San Pedro Shelf sent refracted long period southerly swells right through the entrance of the Long Beach Breakwater toward the Pier J area. Afterward this discovery, a number of shipping companies subscribed to Surfline's surf forecasts to anticipate and plan around these long period south swell events. More recently, modifications have been built near the Pier J area to control this situation.

LONG BEACH SURF - There is a considerable amount of wave energy offshore that can be focused to create very strong surf in the Long Beach area. Before the breakwater was built in the 1940's, Long Beach was an internationally recognized good surfing beach that hosted numerous competitions. There was surf along the entire beach and the best waves were found at the flood control channel and at the southern end near the Alamitos Bay entrance.



Currently with the breakwater in place, there is very little if any surf throughout the entire Long Beach area. There are very rare occasions when there will be some surf found at the eastern portion of the beach on the peninsula between Claremont and 72nd Place. These waves occur primarily during very large south swell or west swell events, when a fraction of the original swell energy will refract and pass around the far eastern end of the breakwater. Additionally, during the wintertime we may occasionally experience strong, local pre-frontal winds out of the southeast, which create large, short period waves very close together that pass through the eastern breakwater gap.



Coastal beach erosion is currently a significant problem in the peninsula area of Long Beach as all of the wave energy in the area approaches the beach from only one direction - the south/southeast. The breakwater blocks any other wave direction that might help to counteract and/or balance the erosion. The wave events that are the most damaging with coastal erosion in Long Beach are large, short period southeasterly swells that are generated by local pre-frontal southeasterly winds - especially when they happen to coincide during a very high tide.

During the 60's, there was a very popular surfing spot at 72nd Place at the eastern end of the peninsula where many of us learned to surf, including Jericho Poppler, a future 1970 World Champion. At that time there was a dredging operation every few years that took sand from the San Gabriel River in Seal Beach, and pumped it over to 72nd Place on the Long Beach side. More sand in the 72nd Place area created much better surf as the waves broke further offshore. Since that sand replenishment operation ceased the sand erosion problem throughout the entire peninsula area appears to have worsened as well as the quality of the surf in that area.

DID YOU KNOW, THAT ON A STRONG LONG PERIOD SOUTH SWELL LONG BEACH WOULD PRODUCE SOME OF THE LARGEST WAVES IN ALL OF CALIFORNIA?

NEXT IN PART 2 - HOW GOOD THE WAVES WOULD BE IN LONG BEACH WITHOUT THE BREAKWATER.
IF YOU WOULD LIKE A COPY OF THIS ENTIRE REPORT YOU CAN DOWNLOAD THE ENTIRE PDF HERE.
Read more about the California coast line with the California Surf Guide by Sean Collins, Buy Here

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