|
Piner Creek is a stream in northeast Santa Rosa, California, United States () which originates as an outlet of Fountaingrove Lake. Piner Creek discharges to Santa Rosa Creek which in turn joins the Laguna de Santa Rosa.〔U.S. Geological Survey, ''Santa Rosa Quadrangle'' (1954, photorevised in 1980)〕 The upper reaches in the foothills of the Mayacamas Mountains are at elevations of 200 to 300 feet (60 to 90 meters), while the lower and middle reaches are located on the Santa Rosa Plain at elevations of between the 110- and 140-foot (33- and 43-meter) contours;〔U.S. Geological Survey, ''Aerial photograph stereo pair series (years 1957, 1965, and 1973)''〕 therefore, these lower reaches have a gradient of about 1:250 toward the southwest. Geologic studies in the lower and middle reaches of Piner Creek indicate groundwater levels ranging from three to 15 feet (one to 5 meters) below the surface.〔''Environmental Site Assessment, 3230 and 3240 Coffey Lane, Santa Rosa, California'' Earth Metrics Incorporated, October 4, 1989〕 Prior to extensive urban development of the middle and lower reaches, the landscape earlier bore extensive agricultural uses including plum orchards, which fruit was subsequently processed for prunes. The Piner Creek watershed consists of , approximately three-fourths of which lies within the municipal boundaries of the city of Santa Rosa.〔(Biological and Physical/Habitat Assessment in the Santa Rosa Watershed (2002) )〕 About one-third of the watershed is developed as residential use, and about one-sixth of the land is open space, recreation and agricultural usage. One of the early surviving architectural features of Sonoma County is within the Piner Creek catchment basin: A well preserved ''Round Barn'', constructed in 1899, a testament to the 19th century pasturage uses within this watershed.〔(History of Sonoma County, California )〕 ==Hydrology== Piner Creek originates in the lower Mayacmas Mountains at Fountaingrove Lake. From its outlet at Fountaingrove Lake, Piner Creek flows down a relatively steep gradient, initially over a riprap lined channel, which has been modified in association with some alterations to lower Fountaingrove Lake. Thence Piner Creek flows northerly of an upscale modern office park before crossing under Redwood Highway and U.S. Highway 101. West of the U.S. 101 Freeway, Piner Creek winds through a retail and commercial/industrial area, before crossing under Piner Road near Coffey Lane; in this reach there is a large historic release to groundwater of solvent from manufacturing uses stemming back to the 1970s and 1980s. Water quality of Piner Creek is characterized by pH levels that are mildly basic, with upper reach pH levels about 8.5, declining to lower reach levels at 7.8 just above the discharge to Santa Rosa Creek.〔''Water chemistry of the Laguna de Santa Rosa Watershed'', Lumina Technologies, Santa Rosa, Ca. (2007)〕 It is interesting to note that the headwaters soils are typically of pH about 6.9. Water quality of Piner Creek is generally low in turbidity, except for highest flow periods resulting from heavy rains; the water is free from odor. Springtime water temperatures are typically in the range of 60 to 65 degrees Fahrenheit (16 to 18 degrees Celsius). Piner Creek terminates at its confluence with Santa Rosa Creek, which watercourse discharges to the Laguna de Santa Rosa; the Laguna de Santa Rosa ultimately forms a confluence with the Russian River, which flows into the Pacific Ocean. 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「Piner Creek」の詳細全文を読む スポンサード リンク
|