What Nature Wrought Over Millenia, a Century of Development Tore Asunder

It would seem a paradox for Southern California, a semi-desert, to have a sprawling network of freshwater streams and marshes.

The explanation lies in the rugged mountains that ring the Los Angeles Basin. Snow runs off the peaks, flowing into rivers and creeks and sinking into sandy soils that fill the lower valleys. The result is plenty of fresh water, snaking its way to the ocean.

But after a century of damming, draining, paving and farming, most of Southern California’s natural marshes and streams have vanished.

California is now left with fewer wetlands than Arizona--about 450,000 acres out of the state’s original 5 million, according to the U.S. Fish and Wildlife Service. That’s an estimated 91% loss, higher than any other state in the nation.

One recent study showed 40% to 60% of the wetlands that existed in San Diego County 10 years ago are gone, and experts believe Orange County, which once had several hundred thousand acres of wetlands, closely mirrors that loss.

The term “wetlands” describes a diverse set of lands that fall into two general categories--saltwater and freshwater.

The most familiar wetlands are salt marshes--the bays and estuaries that dot the coast.

About 3,500 acres are left in Orange County, perhaps 10% of the original. And, like a broken string of beads, the remaining ones--Anaheim Bay, Bolsa Chica, Upper Newport Bay and some smaller parcels--are fragmented.

“There used to be stories of how you could shoot a gun over Bolsa Chica and literally millions of birds would take off--a sight you can only imagine now,” said Gary Gorman, a Huntington Beach resident who co-founded the Huntington Wetlands Conservancy, which three years ago restored the 25-acre Talbert Marsh on the inland side of Pacific Coast Highway at Brookhurst Street.

Salt marshes are filled and drained by rising and falling tides. Birds from thousands of miles away seek out these rich ecosystems to forage; fish travel from the ocean depths to spawn.

Inland, freshwater woodlands--called riparian areas--are hard for most people to recognize as wetlands. Found alongside creeks and streams, they resemble long, thin, miniature forests with usually no water on the surface. Most creeks in Southern California are ephemeral--carrying water only after storms and storing the rest underground.

Roots of willows, cottonwoods, sycamores, cattails and other plants found in these wetlands tap into the underground water.

Freshwater wetlands once filled the flat valley floor around the Marine Corps helicopter base in Tustin--an area once known as the Swamp of Frogs. By the 1920s, however, the plug was pulled on the Tustin and Irvine marshes with the construction of agricultural ditches that drain into Newport Bay.

A century ago, the Santa Ana River flowed freely through three counties, at times covering much of the northern half of Orange County. The river was gradually channeled to provide flood control, and it now resembles a cement ditch through Orange County for all but a few miles between Anaheim and Prado Dam.

Most remnants of riparian wetlands are less than 50 acres apiece. The largest are San Joaquin Marsh next to UC Irvine and the three Laguna lakes in Laguna Beach. Both are severely degraded from urban uses and need restoration before they can become viable habitats for wildlife.

South County also has large riparian wetlands along Upper San Juan Creek and Trabuco Creek. Some of Aliso Creek has been preserved, but only in patches.

“North County has been blitzed, but there’s still a lot of potential for the southern end of Orange County,” said Jack Fancher, a wetlands expert at the U.S. Fish and Wildlife Service. “It’s not paved or built--yet--so the potential is still there.”

One extremely rare type of wetland--vernal pools--has completely disappeared from Orange County. Vernal pools, small depressions with clay bottoms that fill with colorful wildflowers in spring, used to dot Costa Mesa and Irvine, which is built on a flat, broad geologic formation called the Newport Terrace.

Many of today’s inland wetlands exist only because of urban runoff. Irrigation water flows off yards and empties into channels, providing nourishment for willows and other wetlands plants. The area’s largest freshwater marsh--the Prado Basin at the Orange-Riverside county border--wouldn’t exist if it weren’t for waste water and runoff collecting at Prado Dam.

“This place is not the Okefenokee Swamp,” said John Tettemer of Tettemer & Associates, a Costa Mesa firm that restores wooded wetlands. “If we weren’t importing water, you could kiss all wetlands off.”