Пенсильвания штатындағы Дарби өзенінің сипаттамасы

Creek in Pennsylvania, USA

Darby Creek flows through a narrow valley in its upper reaches and a tidal flat in its lower reaches. The creek is in the Piedmont Uplands and Atlantic Coastal Plain physiographic provinces. Major rock formations in the watershed include the Wissahickon Formation. Three small dams historically existed on the creek, but were removed in 2012. The watershed of the creek is largely developed, with roughly half a million people inhabiting it. Most of the watershed is in Delaware County, but some parts are in Chester County, Philadelphia County, and Montgomery County. The watershed is part of the Lower Delaware drainage basin. Historically, the Lenni Lenape people inhabited the area in the vicinity of Darby Creek. By the 17th century, the Dutch and Swedish had arrived in the area, followed some years later by the English. Numerous mills of various types were eventually built along the creek and several railroads traversed the watershed. In modern times, grants by various organizations have been awarded to improve the creek and its watershed. The Darby Creek Valley Association operates within the watershed. Part of the creek's length is designated as a Coldwater Fishery and a Migratory Fishery, part is a Trout Stocked Fishery and a Migratory Fishery. Various species of fish, including redbreast sunfish, eels, and trout, inhabit it. Several areas in the vicinity of the creek are listed on the Delaware County Natural Areas Inventory. These include the Darby Creek Mouth Mudflat, the John Heinz National Wildlife Refuge, and the Ithan Darby Creek Wetlands. A reach of the creek is navigable by canoe.

Darby Creek begins in a small valley near US Route 30 in Tredyffrin Township, Chester County. It flows south southeast for more than a mile before entering Easttown Township and turning east northeast for several tenths of a mile. The creek then turns southeast for a few miles, passing through Newtown Township, Delaware County and entering Radnor Township, where it receives its first two named tributaries, Thomas Run and Little Darby Creek, from the right and left, respectively. The creek then turns south southeast for several tenths of a mile before turning southeast for several more miles. In this reach, it receives the tributary Miles Run from the left and the tributary Camp Run from the right. The creek eventually turns east briefly before receiving the tributary Ithan Creek from the left and turning south southeast for several miles along the border between Marple Township and Haverford Township. In this reach, the creek flows alongside Interstate 476 and crosses it once. As it continues downstream alongside the highway, it crosses Pennsylvania Route 3 and receives the tributary Longford Run from the left. Near Pilgrim Gardens, it turns southeast again and begins to flow along the border between Upper Darby Township and Springfield Township, crossing US Route 1 and receiving the tributaries Colleen Brook and Lewis Run from the left and right, respectively. Further downstream, the creek's valley becomes much steeper and narrower and it makes several meanders as it passes by Clifton Heights and Landsowne before flowing along the border between Aldan and Yeadon. The creek then flows south southeast for a few miles, leaving its valley and passing Darby, Collingdale, Sharon Hill, and Colwyn as it crosses US Route 13. It then receives the tributary Cobbs Creek from the left. The creek then receives Stony Creek, its last named tributary, from the right and turns south for a few tenths of a mile before reaching its confluence with the Delaware River.

Tributaries of Darby Creek include Cobbs Creek, Little Darby Creek, Ithan Creek, Muckinipattis Creek, and numerous others. The elevation of the creek's source is between above sea level. The rocks from the northern portion of the watershed date to the Precambrian Era and Lower Paleozoic Era. The rocks from the southern portion of the watershed are newer, dating from the Tertiary and Quaternary Periods. Darby Creek tends to be a fast stream with some riffles. There is also whitewater in places. The creek is a "radically intermittent storm drain" in its upper reaches and a tidal estuary in its lower reaches. It passes through the only substantial tidal wetlands in Pennsylvania. During several measurements in the 2000s, the water temperature of Darby Creek at Foxcroft ranged from The air temperature in the area ranged from The barometric pressures range from 759 to 762 mm Hg. The average annual rate of precipitation in the watershed of Darby Creek is between .

The watershed of Darby Creek has an area of 77.2 square miles (200 km2). Neighboring major watersheds are Crum Creek to the west and the Schuylkill River to the east. The creek serves as the county line between Delaware County and Philadelphia County for a reach of 2 mile (3 km). A large part of the watershed of Darby Creek is located on developed land, with many suburbs of Philadelphia are in the watershed. A Superfund site known as the Lower Darby Creek Area site is located in the vicinity of the creek. This site consists of two landfills. Major roads in the watershed include Interstate 95 and Interstate 476.

Darby Creek was entered into the Geographic Names Information System on August 2, 1979. Its identifier in the Geographic Names Information System is 1172928. According to the Geographic Names Information System, variant names include Church Creek and Derby River. The Lenape named the creek "Muckruton", which appeared on several early maps. The first Europeans to come to the area in the vicinity of Darby Creek were the Dutch, though they did not establish any permanent settlements. In 1643, Swedish colonists led by Johan Printz established New Sweden near the confluence of Darby Creek and the Delaware River. The settlement they established served as the seat of government for the Swedes in North America for 12 years. They may have built impoundments in the creek to isolate marsh areas. Dutch settlers conquered the Swedish villages in 1655. In 1664, the Dutch surrendered the Darby Creek drainage basin to the English, who began settling the area after William Penn was issued a charter in 1681. In Springfield Township, Rolling Green Park was expanded when six homes were ravaged by the hurricane and had to be demolished.

The main stem of Darby Creek is designed as a Coldwater Fishery and a Migratory Fishery from its source to the Pennsylvania Route 3 bridge. From that point downstream to its mouth, the non tidal portions of the creek's main stem are a Trout Stocked Fishery and a Migratory Fishery. Numerous fish species were observed in the creek during a 2009 electrofishing survey by the Pennsylvania Fish and Boat Commission. The catch per unit effort per hour rate for smallmouth bass was slightly over 10 and the rate for rock bass was under 10. The catch per unit effort per hour rate for redbreast sunfish was 123, the highest of several warmwater streams tested during the survey. Some stocked rainbow trout and brown trout were also captured in the creek. High numbers of American eels were observed in the creek was well. Fish species such as mummichogs, silvery minnows, striped bass, and white perch were found at the head of tide of the creek. Brown trout naturally reproduce in the creek's headwaters. The Darby Creek Mouth Mudflat, which is a remnant tidal flat at the mouth of Darby Creek in Ridley Township and Tinicum Township, is inhabited by 14 "species of concern". At the John Heinz National Wildlife Refuge, which is a tidal estuary along the creek, supports various plant and animal species and is a critical migratory habitat for waterfowl. It is also designated as a National Wildlife Refuge. The Ithan Darby Creek Wetlands contain old fields, wet meadows, and riparian buffers. They are inhabited by one "species of concern". The Darby Creek Trail is a mile long trail that follows the creek in Haverford Township and is anchored by Merry Place, a park and nature area at its southern end. A multi use trail along Darby Creek has been proposed. The trail would run from Garrett Road in Upper Darby Township to Pine Street in the borough of Darby. A portion of this trail in Drexel Hill along a stretch of the creek that formerly hosted criminal activity was completed in 2018. There are many public parks that line Darby Creek, with some having large recreation areas with athletic fields for baseball, soccer, and football, and others containing woodlands and nature trails. There are a total of eight golf clubs bordering the creek, featuring some of the largest stretches of undeveloped land in the watershed. The Ridley Township marina is located on the lower end of the creek. Darby Creek is a popular site for angling. It is stocked annually by the Pennsylvania Fish and Boat Commission, and by a number of local sportsman organizations. The former has been stocking progressively fewer trout every year for some time.