At quarter to three this morning I got out of bed, opened the back door for the dog. Becky woke me again at 5:45. “I think Zeke got skunked.” I roused, smelled a faint odor of Mephitis. I called Zeke to the bed. No skunk spray: just the regular disgusting smell. We went down to the park.
It had rained during the night, and the creek was up again. It filled a third of its channel. The New Year’s flood brought it out of its banks, into the yards of stream-side homes. When it receded the water left a wrack of change. Tree trunks lay up against the train trestle in an upstream stack six feet high. When we moved here there was one small drop on this section of creek, a ledge of about two inches near a prominent tree halfway to the bay. I called it “Buckeye Falls” and imagined brave rafters the size of pocket mice. After January’s flood a cascade of small riffles ran from San Pablo Avenue to tidewater. The creek had scoured the Corps of Engineers channel, sculpted carefully by backhoe and dozer to control floods, banks reclining just below the angle of repose. Instead, the flood controlled the channel. From order came a different order. Bends in the stream remained, bars and cut-banks, back-channels and rolling, v-shaped tongues for the mallards to ride.
Today the water tore at the landscape it had built. What was for the last two months a flat gravel bar at the top of the park now bore a knife-edge ridge four inches high above the waterline.
There is a spot across the bay where people decided to breach the dikes, to let the bay reclaim former hay farms as salt marsh. It was a legacy of our last transportation regime. Chinese laborers stood hip-deep in water for years piling mud to build levees. Farmers filled the marshes behind them to grow fuel for horses. Peak Hay came and went but a few farms still remained, unconverted to cities, when public sentiment turned from reviling worthless swamps to cherishing our irreplaceable wetland heritage. The engineers opened up channels into the farm a little at a time. They worried that too broad a breach would fill the bay with wave-eroded silt. The channels were twenty feet across, and long, to blunt the energy of wind-blown waves. A few seasons, they said, and gentle tides would carry silt into the lowland farms. Cordgrass marsh would replace the hay in rich, productive marshes a few inches deep. They dumped dredge spoils from the Port of Oakland to start things off.
I visited six years later. Tides had carved the breaches into deep channels, carried the dredge spoils back into the bay. Cormorants dove headlong for fish in the old hayfields. The engineers scratched their heads. It was the narrowness of the channel, some said. The lack of meanders, said others. Look at natural marshes: is there a straight slough in any of them? Still others noted the diving ducks, said they had restored a wetland, and changed the subject.
A thousand feet west the Port Sonoma Marina, a series of pools connected to the bay by a small channel, is silting up quick. It is dredged once a year, at great expense. Palo Alto’s yacht harbor grows cordgrass. Alviso was once the South Bay’s busiest port. From the Bay you might be able to kayak to Alviso now, at flood tide, in a wet year. Water does what it will.
That flat gravel bar in Pinole Creek may be gone by tomorrow. The hills will renew it soon enough. Dredged up out of the earth as one tectonic plate scrapes along another, the hills are growing faster than erosion can level them. Green serpentine from the earth’s mantle, sand laid down on the bed of a Miocene sea, shale made of silt washed down from the Sierra, diatomite from a deep trench off Monterey: all mix as pebbles in the bed of Pinole Creek. All of them will wash out to the bay, eventually. A gravel delta runs fifty yards out from the creek mouth now. It was not there last year. At quarter to three tomorrow morning the tide will wash over it again.
Posted by: Chris Clarke
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