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Alhambra Creek is a stream in Contra Costa County, California in Northern California which drains into the Carquinez Strait in Martinez by way of the historical Arroyo del Hambre. Alhambra Creek and its valley take their name from Cañada del Hambre, Spanish for "valley of hunger", apparently because of some unknown incident involving starving Spanish soldiers. The name appears on diseños repeatedly and appears on an 1842 land grant, Rancho Cañada del Hambre y Las Bolsas. Although technically Alhambra Creek only refers to the upper section of , and the United States Board on Geographic Names in 1943 confirmed Arroyo del Hambre as the name for the lower creek, Mrs. John Strentzel, John Muir's' mother-in-law, did not like the name and renamed the lower creek also as Alhambra Creek. Currently the entire creek is commonly called the Alhambra Creek, and Arroyo del Hambre Creek and Franklin Creek are considered its two tributaries. The Alhambra Creek Watershed covers approximately in north central Contra Costa County and encompasses a portion of the city of Martinez. The combined branches flow through Briones Valley, valleys containing open space, wildlife habitat, residential and commercial areas, through downtown Martinez and then discharge into the Carquinez Straits through a tidal wetland at the Martinez Regional Shoreline.〔(【引用サイトリンク】author=Alhambra Creek Watershed Planning Group )〕 Alhambra Creek originates in the hills of Briones Regional Park. The water flows from a tunnel in the side of the hill. This tunnel was made years ago to try to tap into what the speculators thought was a vast underground river that came from the Sierras. The thought was that the lagoons on Briones Crest represented a vast underground store of water. This “aqueous mother lode” turned out to be illusory, so the tunnel was abandoned. The linear distance from the source to the mouth of Alhambra Creek is about . For the first , Alhambra creek descends from about elevation to . At this point, it is joined by Arroyo del Hambre Creek, which comes from a source at an elevation of about , to the west. Arroyo del Hambre Creek is joined by several tributaries, among them Vaca Creek, on its way to join Alhambra Creek. Franklin Creek joins Alhambra Creek about below the confluence of Alhambra and Arroyo del Hambre Creeks. Franklin Creek drains a subwatershed of roughly the same size as the combined Upper Alhambra and del Hambre basins. It originates about 3 miles (5 km) northwest of its confluence with Alhambra and flows southeast through Franklin Canyon then bends to the north to flow through the John Muir National Historic Site and joins Alhambra Creek between Walnut Avenue and Alhambra Way. There are no reservoirs and no heavy industry in the watershed. An oil refinery is located just over the ridge to the east, and two railroads and a freeway cross the watershed.〔 ==Beavers in Alhambra Creek: past and present== (詳細はbeaver arrived in Alhambra Creek in downtown Martinez. The beavers built a dam wide and at one time high, and chewed through half the willows and other creekside landscaping the city planted as part of its 9.7 million 1999 flood-improvement project. The City Council wanted to remove the beavers because of fears of flooding, ironically, as the worst flood since the flood control project was in 2005, two years before the beavers came. Local residents organized to protect them, forming an organization called ''Worth a Dam''. Resolution included installing a flow device pipe through the beaver dam so that the pond's water level could not become excessive. Now protected, the beaver have transformed Alhambra Creek from a trickle into multiple dams and beaver ponds, which in turn, led to the return of numerous birds, steelhead trout (''Oncorhynchus mykiss'') and river otter (''Lontra canadensis'') in 2008, and mink (''Neovison vison'') in 2009. Examples of the impact of the beaver as a keystone species in 2010, include a green heron (''Butorides virescens'') catching a tule perch (''Hysterocarpus traskii traskii''), the first recorded sighting of the perch in Alhambra Creek and the December arrival of a pair of hooded mergansers (''Lophodytes cucullatus'') (see photos). The beaver parents have produced babies every year since their 2006 arrival. However, in June, 2010, after birthing and successfully weaning triplets this year (and quadruplets the previous three years), "Mom Beaver" died of natural causes. In November, 2009 the Martinez City Council approved the placement of an 81 tile wildlife mural on the Escobar Street bridge. The mural was created by schoolchildren and donated by ''Worth a Dam'' to memorialize the beavers and other fauna in Alhambra Creek. The Martinez beavers probably originated from the Sacramento-San Joaquin River Delta. Historically, before the California Fur Rush of the late 18th and early 19th centuries, the Delta probably held the largest concentration of beaver in North America. It was California's early fur trade, more than any other single factor, that opened up the West, and the San Francisco Bay Area in particular, to world trade. The Spanish, French, English, Russians and Americans engaged in the California fur trade before 1825, harvesting prodigious quantities of beaver, river otter, marten, fisher, mink, fox, weasel, harbor and fur seals and sea otter. When the coastal and oceanic fur industry began to decline, the focus shifted to California's inland fur resources. Between 1826 and 1845 the Hudson's Bay Company sent parties out annually from Fort Astoria and Fort Vancouver into the Sacramento and the San Joaquin valleys as far south as French Camp on the San Joaquin River. These trapping expeditions must have been extremely profitable to justify the long overland trip each year. It appears that the golden beaver (castor canadensis, subspecies: subauratus) was one of the most valued of the animals taken, and apparently was found in great abundance. Thomas McKay reported that in one year the Hudson's Bay Company took 4,000 beaver skins on the shores of San Francisco Bay. At the time, these pelts sold for 2.50 a pound or about 4.00 each. The Delta area incidentally, is probably where McKay was so successful, rather than the Bay itself. In 1840, explorer Captain Thomas Farnham wrote that beaver were very numerous near the mouths of the Sacramento and San Joaquin rivers and on the hundreds of small "rushcovered" islands. Farnham, who had travelled extensively in North America, said: "There is probably no spot of equal extent in the whole continent of America which contains so many of these muchsought animals." 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alhambra Creek」の詳細全文を読む スポンサード リンク
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