By Judy Raskin
Natural bodies of water have things in them, like stones and gravel, kelp, fallen trees, and greenery of one kind or another. But Echo Park Lake is a man-made lake, which means the designers who worked on rebuilding this urban body of water looked for ways to imitate nature for the benefit of fish, birds, and, let’s not forget human beings, that will enjoy it.
The lake is just a big hole in the ground now, with huge construction machines pushing dirt this way and that. The lake bed has to be lined to keep the water from seeping into the ground. What would that look like, I wondered? My vision of a massive enamel bathtub was outlandish, I admit. How would the fish survive without places to hide or spawn? How would the wading and diving birds get into the water to feed on the fish?
I called Katherine Clark of the Los Angeles Bureau of Engineering and Brian Young at the California Department of Fish and Game for some answers.
Clark said that “the lake liner is a 12-inch thick layer of bentonite-enhanced clay. The soil underlying the lake is for the most part clay, which means that water does not infiltrate easily through it. We’re taking advantage of this fact by using the existing low-permeability soil and mixing it with bentonite. The bentonite will expand as it comes in contact with the water, creating a nearly impermeable layer.”
The lake will have variable depths, she added. “In the lotus bed area, the water level will be between 12 and 18 inches. The wetland areas will range from 3 to 5 feet in depth. At the south end, the deepest part will be about 8 feet.”
If you go down to the lake now, while the workers are doing the job, you’ll notice how they are creating these depth zones, which will be unseen once the lake is filled with water. The perimeter of lake is mostly lined with what appears to be river stone (“rip-rap slopes”), and similar stones line elevated areas within the lake bed. The northeast corner of the lake (Echo Park Avenue at Park Avenue) has a good view of this. Vegetation will be added at a later time.
Another major element of the lake that will be mostly hidden by water is a 12-inch thick wall made with 4,000-cubic yards of concrete and reinforced with steel rebar. It follows the contours of the lake, and, with the exception of a few breaks near the boathouse and bridge, will completely encircle the body of water.
Fish will be able to take shelter amid the flexible limbs of more than 80 tree and shrub-shaped “fish attractors” that will serve as an underwater habitat. As for birds, they will be able to enter the lake at several points, either through the vegetated and rip-rap slopes around the lake, including entirely around the island, a small section along the east side of the lake and around the peninsula.
The lake will be partially refilled as early as this winter. The contractor needs some water in the lake in order to begin planting the lotus and other wetland plants. Construction and full refilling is expected be complete by spring 2013.
Judy Raskin in an Echo Park resident involved in bird and wildlife issues.