Sacramentoâ€“San Joaquin River Delta
The Sacramento - San Joaquin River Delta is a large inland delta and estuary in northern California on the Pacific Coast of the United States of America.
The delta is formed by the mouth of the Mokelumne River and the Calaveras River in the San Joaquin River, and desselbigen in the Sacramento River at the western end of the Central Valley. The only outlet is the Carquinez Strait, which leads over the bays of San Pablo and San Francisco and the Golden Gate into the Pacific.
The delta consists of countless canals and natural waterways ( Slough ) which has a number of islands (sometimes called Tract ) and wetlands form. Due to soil erosion, most of these islands are located below the water level of the surrounding canals or rivers; a system of dikes to protect against flooding.
The Delta is an estuary with a catchment area of over 150,000 square kilometers. The catchment area extends from the southern end of the Cascade Range in northern California along almost the entire western flank of the Sierra Nevada. Over thousands of years, regularly flooded flooding and snow melt, large parts of the Delta.
Towards the end of the California gold rush began with the help of Chinese workers to draw channels and build dikes to gain land for agriculture. These channels were first excavated manually, only around 1870 also steam powered dredger ( " Clamshell Dredgers " ) were used, until the end of 1920, the present form of the delta has been reached.
Around this time the steamship reached its peak in the Delta and its tributaries, and you could travel comfortably bluff from San Francisco to Sacramento, Stockton, and even up to Fresno or Red. Around this time there were up to 300 paddle steamer in use, of which the legendary sister ship Delta King and Delta Queen were the greatest. However, when in the 1930s bridges like the Golden Gate Bridge, the Bay Bridge and Carquinez Bridge were opened and thus the traffic in the north and west facilitated critical steam navigation was in the Delta declines rapidly until it after the outbreak of the Second World War was set almost entirely.
The onset due to the soil conditions and intensive agricultural use of soil erosion has greatly lowered the created islands - sometimes more than 6 meters - so that whole dike routes are threatened with collapse. Several dikes were the result (eg Franks Tract and Mildred Iceland ), the last occurred on 3 June 2004 16 km west of Stockton, which broke a 110 m long dike piece and the Upper Jones Tract - a 49 km ² large island - - flooded. After similar dikes were increasingly likely, California Governor Arnold Schwarzenegger signed on 19 May 2006, a billion program to repair and upgrade the levees in the Delta.
Due to the mild climate, the fertile peat soils and the abundant supply of water intensive agricultural activity in the delta, the billions of dollars contributing to the gross domestic product of the California economy. Crops are also numerous specialty crops such as citrus fruits, fruit, asparagus and lately also reinforced viticulture. There are sometimes several harvests a year possible.
In addition, the Delta supplies some 25 million people - about 2 /3 of the population of California - with drinking water and a large proportion of agriculture in southern California with irrigation. Water is withdrawn in the south of the delta, at the Clifton Court Forebay. Both the California Aqueduct - the major parts of the Central Valley as well as supplies Los Angeles - as well as the South Bay Aqueduct - which results in the Silicon Valley and the San Francisco Bay Area - are fed from here.
The Delta with its " Thousand Miles of Waterways " is also a large recreation area. Warm summer days, moderated by the so-called Delta Breeze, attract many water skis, wake boarders and pleasure boats. In the cooler, fog ( " Tule Fog" ) imprinted winter months, particularly anglers and hunters are to be found.