Blue Lagoon : San Elijo Estuary Serves as Sanctuary to Watery Wildlife

A great blue heron ambles on stilt-legs across the reed-fringed shallows, stabbing occasionally at subsurface morsels of food. Nearby, a willowy egret glides in for a perfect landing, scattering concentric ripples across the surface of the lagoon. Both birds seem oblivious to binocular-toting humans, who spy on them from a hillside a comfortable distance away.

A scene like this is repeated almost daily at San Elijo Lagoon, one of North County’s most attractive coastal estuaries.

Bisected by Interstate 5 and rimmed by expanding suburban development, the area has become the focus of considerable conservation effort. Local citizen groups, the San Diego County parks department, and California’s Department of Fish and Game have teamed up to restore this long-neglected and formerly unappreciated resource.

Now managed as an ecological reserve, the lagoon and most of the surrounding shoreline have become an important natural and recreational resource for the North County region.

The lagoon consists of two principal parts: the West Basin, which fills to a depth of several feet at high tide; and the East Basin, which remains mostly dry (but marshy) except during times of flooding or very high tides.

The lagoon, one of the best remaining examples of a coastal wetland in Southern California, plays multiple roles in the local ecology. When floodwaters course down Escondido Creek, they dissipate their energy here, reducing erosion down along the coastline itself. Several kinds of ocean-going fish spawn in the lagoon’s calm waters. The rich supply of nutrients in the muddy bottom are food for snails, shrimps, crabs and clams--and these in turn are food for the nearly 300 species of birds that visit or nest here.

Foot travel along the lagoon’s perimeter is encouraged, as long as you stay on the designated paths. You can bring your pet, if it’s kept on a leash. Mechanical conveyances are banned--mountain bikes included. Also keep in mind that collecting specimens of any kind is not allowed.

Staying cool and comfortable while out hiking in August can be problematical, but not impossible, as long as you confine your explorations to the early morning or evening twilight times. Here’s a brief look at the paths:

West Basin

From the north terminus of Rios Avenue in Solana Beach, you can either walk north toward a neck of land protruding into the lagoon (a good bird-watching spot), or east along the lagoon’s shoreline.

The east path starts with a passage through dense, jungle-like vegetation: giant castorbean trees, and lots of fennel, a weedy plant that smells like licorice. These are non-native plants that long ago displaced some of the original sage-scrub and chaparral. Shortly, you break out into the open, where the sage-scrub vegetation grades down to mats of salt-tolerant pickleweed and the shallows of the lagoon.

The trail divides: you can veer left and get closer to the water’s edge, or stay right on an upper path that heads more directly toward a grove of eucalyptus, acacia, mimosa, alms, and other non-native trees, just short of Interstate 5. From the upper path you can take a side trail south into secluded Holmwood Canyon. An abandoned orchard is tucked away halfway up the canyon’s broad floor.

East Basin

By descending from the Lomas Santa Fe streets called Santa Inez and Santa Carina, you quickly reach the main path along the south shore of East Basin.

From the west end of that path you can follow a flood-control dike leading north to Manchester Avenue near Mira Costa College (yet another entrance to the reserve). Or you can follow a path cut along the I-5 freeway embankment leading toward the West Basin trails.

Heading east you won’t see much water, but there’s lots of interesting vegetation and wildlife. Scattered eucalyptus, willow, cottonwood, and elderberry trees serve as resting spots for the sleek, black ravens patrolling the skies. Cottontail rabbits are everywhere, their tails bobbing as they flit between clumps of russet-brown buckwheat.

Black sage and California sagebrush, though withered at this time of year, add their own perfume to the moist, salt-tinged air moving in from the ocean.

About a mile east of I-5, you’ll thread your way through an intriguing eucalyptus grove, dark and damp even on the brightest days. Just a bit farther, the path strikes El Camino Real at a point south of La Orilla, a road leading into Rancho Santa Fe.