Seeking to Shore Up Coast : Seal Beach Study Is Part of Effort to Learn How, Where Sand Travels

Each day, right after he checks into work, Seal Beach lifeguard Lt. Steve Cushman heads for a spot north of the pier. It is here, near the crashing surf, where Cushman makes a series of intricate observations that may help unlock the secret of vanishing sand along Orange County’s coastline.

With notebook in hand, Cushman, 42, records the size of the surf, how the waves broke, ocean temperature and wind speed. Then he tosses a dye packet in the water. Within a minute and a half, tidal action sends the fluorescent green dye slowly north, as Cushman measures its movement.

“It looks like about 14 feet today,” he said.

Seal Beach is part of a network of 45 data-gathering sites that officials hope will help the U.S. Army Corps of Engineers learn how and where sand travels along the county’s shore.

“We even make notes on how the wave spills over,” Cushman said. “They can be slow spillers or plungers, waves that plunge over and gouge out sand.”

In addition to Cushman and other lifeguards, county divers and surveyors have been busily recording observations from the shore seaward. In some areas, monitoring extends nearly two miles offshore.

Begun in 1991, the Coast of California Storm and Tidal Wave Study is a $2.5-million, five-year survey that last month engaged the help of lifeguards such as Cushman. The coastal study includes a 32-mile area from Dana Point north to the San Gabriel River Jetty in Seal Beach. It is the Army Corps’ second comprehensive study of the state’s coastline since the completion of a San Diego area survey spanning the U.S.-Mexico border to Dana Point in 1987.

“The study is to give us an understanding of where the sand is coming from and where it’s going,” said Robert Nathan, a spokesman with Moffatt & Nichol, a Long Beach coastal consulting firm hired by Seal Beach. “You can’t just isolate and look at one beach. You need to look at the entire system. That means sources of sediment, dams, flood control work, sources of waves and their direction.”

While some beach watchers say sand erosion and replenishment are as simple as “summer you get it, winter you lose it,” others are not so convinced.

True, Orange County is susceptible to winter’s big, northwest storms that slam and scour away sandy beaches. Big summer storms from the south tend to push sand shoreward, replenishing sand-starved beaches.

But man-made obstacles, such as piers, jetties and dredging at river mouths have added complexity to sand travel, said Thomas Rossmiller, the study’s coordinator for Orange County’s Environmental Management Agency.

In addition, natural sediment sources have been altered by man. For example, mounds of dirt and rock that serve as mini-dams along the San Gabriel River near Seal Beach trap sediment. Instead of flowing downriver, the sediment is dug out and trucked for use in construction projects.

Rossmiller said that even with a sophisticated knowledge of the coastline, “there is much we don’t know.”

Some questions they hope to answer include: How much does sand move in a year and under what conditions does it move? Is it cost-effective for Newport Beach to help pay for replenishment at Surfside in Seal Beach or at the Santa Ana River mouth? Is Huntington State Beach’s wide sandy area the result of sediment from the Santa Ana River or sand from the Surfside area?

Relying on the wrong information can be costly. In Oceanside, officials in the 1980s declared war on beach erosion and trucked in 900,000 cubic yards of sand from the nearby San Luis Rey River. The next year, the sand was all gone.

Experts contend the problem was the consistency of the river’s sand, which was not as coarse as the kind carried by the ocean. Consequently, it washed away.

Already, the environmental clock is ticking away along Orange County’s eroding coastline.

Along Huntington Beach and Seal Beach, the coasts are eroding at a combined average rate of 300,000 cubic yards each year, according to the Army Corps of Engineers. At about 18 cubic yards per truck with trailer, that is the equivalent of more than 16,000 loads.

Huntington Beach officials hope something can be done to save the imperiled cliffs along Pacific Coast Highway between Bolsa Chica State Beach and Golden West Street. Last year’s heavy rainfall and ocean storms battered the bluffs and accelerated erosion.

“The problem is that 50% of the time, you have ocean water right up to the bluffs because of high tide,” said Donald Noble, a Huntington Beach public works official in charge of coordinating action on the bluffs erosion. “These bluffs are important regionally and there are areas where you can’t walk on the beach anymore because the waves lap against the face of the bluff.”

A jetty, Noble said, may solve the immediate problem, but can cause problems for beaches north and south of Huntington Beach by shifting sand patterns. In addition to the Army Corps’ study, Huntington Beach is proposing a separate study of the bluffs.

At Surfside, tons of sand--1.8 million cubic yards in 1990--are pumped onto the beach every three to five years. It is a feeder beach, Rossmiller said, and sends tons of sand in a southerly direction as far away as the Wedge in Newport Beach.

Rossmiller noted that sand replenishment is expensive. Currently the sand is obtained by offshore dredging, but some experts fear that may someday dry up as a source for filling in beaches.

In Laguna Beach, coastal residents are grappling with the controversial use of seawalls to protect tiny stretches of seashore. Seawalls can increase water velocity and create circular currents that could affect sand deposits on adjacent beaches.

In Seal Beach, Cushman said, city crews have built a sand berm to protect homes from large surf that develops during big winter storms.

“I remember one year we had a terrible storm,” he recalled. “The waves were getting closer and closer to that berm. Then, one giant wave crested it and took out the top six feet of sand. The next huge wave pushed that sand right through the windows of the bottom floors of the homes on 13th and 14th streets.”

Cushman remembers that when he first began the testing, people immediately came up to him as he tossed dye in the water, worried about whether the dye was toxic.

“Almost every day that we take the measurements and throw the dye in the water, people get nervous,” he said. “But I explain that it’s biodegradable and nontoxic and once they hear that it’s for a study that may help the beach, they understand. I believe that anything we can do to save the beaches is good.”