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RedditWith the clear, cold stream and the acrobatic game fish, we might be somewhere in a remote mountain setting. In fact, not far above us roar the trucks and minivans of a six-lane Interstate, and if it were not for the intervening trees we could see the nearby Hoover Tower of Stanford University and the office buildings of Silicon Valley. Johnson, an antiquities restorer by trade, is a part-time streamkeeper for this urbanized little rivulet and other tributaries of San Francisquito Creek, whose 43-square-mile watershed rises near the notorious San Andreas Fault and eventually empties into San Francisco Bay. "We" are some 300 college students, Silicon Valley engineers, teachers, housewives and Stanford faculty dedicated to monitoring and restoring it to what it was in the more benign days when the Ohlone Indians inhabited these parts. Thanks to the volunteers, says Debbie Mytels of the San Francisquito Creek Watershed Project, which coordinates the restoration campaign, "we're seeing steelhead where they haven't been seen for a hundred years."
Ariane Bertrand, assistant director of the Coyote Creek Riparian Station in San Jose, California, which trains the volunteers and oversees their efforts. A Thalweg is a basic step in understanding the physical characteristics of a stream, Ariane explains. It charts the deepest part of a river or channel throughout its course so that later observers can detect changes, track them to their source and, possibly, correct them. For instance, upstream construction can cause silting downstream. Mud slides can alter the creek's course.
I stand in the stream holding a telescoping surveyor's rod, calibrated in tenths of a foot. Volunteer Roberta Bischel squints at me through the 20-power lens of a survey level mounted on a tripod. "I can't see anything but his fingers," she complains. I move the offending fingers. "Four point six-two," she calls out to Diana Brumbaugh, a San Francisco State University graduate student, who notes the number in her log.
The figure, when subtracted from the instrument height, Diana explains, represents the elevation of the streambed at that location in relation to a bench mark whose elevation is known. "What's the composition of the bed?" she asks me. I look down at my feet. Having been briefed on the differences among silt, sand, gravel, cobble and boulder, I vote for a combination of gravel and small cobble. Diana makes another entry, meanwhile noting where the stream banks have eroded and the type of surrounding vegetation.
"If someone comes back to this spot next year and finds silt instead of cobble, they'll know to look for a problem upstream," Ariane says. She beckons me to move the rod some five yards farther along. Satisfied with my new location, she gestures to Roberta, who squints through the eyepiece; Diana makes more notes. We move the rod again, and slog slowly upstream until, after three hours, we have charted some 100 yards of waterway.
Largely through the efforts of the Environmental Protection Agency (EPA) and the Izaak Walton League's "Save Our Streams" program, waterway restoration is being conducted all across the country. Much of it is carried out by schoolchildren.
Because of its Mediterranean climate, however, California differs from other areas. When the rainy season ends in April, many streams simply disappear, not to reappear until November. Even the San Francisquito, which alternately bubbles and roars during winter storms, by late spring percolates into a gravel bed about five miles from its mouth.
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