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Water High, Land Low |
CALIFORNIA DELTA ----- Islands are bodies of land surrounded by water, right? And there are hundreds of islands in the Delta - all surrounded by water. Here, though, there is a difference - the water is HIGHER than the island! That's right - the land surface of the island is below sea level. Each island is surrounded by a levee to hold out the water. |
UNIQUE
-----Most of the islands, are farmed - some of the most productive farmland in America. You have certainly eaten vegetables grown on these 'islands.'
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Two Views - Same Place - Two Directions
On the Levee
----- Imagine it. You boat around 1,000 miles of waterway, always with a levee beside you and always higher than the surrounding land.
Life Between the Levees - Nice, Eh?
-----It is a unique experience to step off your boat at a marina, casually walk up to the office to pay your fuel bill, and 'discover' you are higher than all the land beyond. Even after a few weeks of Delta cruising, this always came as a shock to us. Most buildings are behind the levees and much lower than the water, a few are on the levee, and very few are on pilings between the levee and the river.
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Sitting on the Levee, Pilings in Front; Sitting Behind the Levee
-----It has not always been so. Native Americans lived here for millennia. When they first settled in the Delta, the Sierras were shrouded in glacial ice. Rain fell in abundance on the mountain flanks. Every spring the Sacramento and its tributary streams were raging torrents of snow and ice melt. Floodwaters bore the glacially ground debris of the Sierra and dumped the fertile detritus into the tidewater bays, flooding them with rich sediment. A vast delta of mud and silt, with twisting branches of brown water, filled the bays. The first Native settlers were attracted by the mild lowland climate and the incredible concentration of fish, birds, and animals. They lived on the low, above-water islands of alluvial sand and mud, and retreated to the highlands during the annual spring floods. They thrived.
-----The Sacramento is a mighty river. Rising in the Klamath Mountains, 50 miles from the Oregon/California border, it flows 400 miles to the south before debauching into San Francisco Bay. It gathers water from its many tributaries, themselves sizeable rivers - the Feather, American, San Joaquin, Tuolumne, Mokelumne, and Stanislaus. Almost half of California's annual water runoff comes down the Sacramento drainage.
----- In March 1772, human history took a new turn. Spanish explorers found the Delta. They were seeking new lands and fortunes, probing northerly from their colony in Mexico. Pedro Fages and Fray Juan Crespi struggled to the top of Mount Diablo to better view the surrounding terrain - and spied a huge inland lake to the east - the Delta inundated by spring floods. Gabriel Moraga named the largest river flowing into the delta - El Rio del Sacramento. Word traveled, and by the early 1830's, French and American fur trappers were attracted to the Delta by the abundance of beaver and otter. Even the legendary mountain man Jedediah Smith tramped through the Delta.
-----In 1848, gold was discovered on the American River, a tributary of the Sacramento, and everything changed. Thousands rushed to the gold fields. In 1849, clippers and sailboats brought Argonauts around the Horn to San Francisco from all over the world. The Delta, to the east of the Bays, lay as a swampy barrier between the sea and riches. Steam power breached that obstacle as hundreds of paddle wheelers carried men and goods to the fledgling towns of Stockton and Sacramento. The route to gold was overland from there.
-----Boom is followed by bust, and most of the gold seekers arrived too late to find their bonanza. Discouraged, men drifted back from the mountains and settled in the Delta to raise enough food to survive. The rich peat soil was amazingly fertile, and crops flourished. Gold, from a different source, had been discovered. But, farming beyond subsistence was difficult. Floods destroyed any permanent structures, and whole islands washed away. Dikes were built in the 1850's, but within a few years, floods carried them away.
-----In 1868, after the construction of the Central Pacific Railroad, there were thousands of newly unemployed Chinese laborers in the area. They were hired to laboriously build levees to hold back floodwaters from the fields. They worked by hand, with shovels and wheelbarrows, and the era of large-scale farming began.
-----A few years later, steam-powered clamshell dredges, mounted on barges, replaced human labor and vast areas of the swamp were leveed, drained, and put into production. Any area of water was fair game for the dredgers, and soon the Delta was a vast array of more than 50 major 'islands,' below sea level, surrounded by dikes and waterways draining the river flow and floodwaters through the Delta.
-----There are hundreds of smaller mud islands, without levees, in the middle of the sloughs and channels. These are covered with vegetation, or lurk just below the water surface. They are constantly shifting with each spring flood.
-----Of course, floods periodically spell disaster and ruin to some. Any breach in a dike, and the fields, homes, roads, and equipment are inundated. Today, huge clamshell dredges are constantly at work, deepening channels to maintain river flow and reinforcing levees.
-----Therefore, when you cruise the Delta, levees, armored with riprap, bound your course. All structures built between the water and the levee are on pilings. A few buildings are on the levee but most lie in the lowland. You cruise above the farmland, houses, and towns. You are in for a unique experience.
(11/03)
