Река Схохари: История, Экология и Проблемы

Schoharie Creek is a river in New York that flows north 93 mile (150 km) from the foot of Indian Head Mountain in the Catskills through the Schoharie Valley to the Mohawk River. It is twice impounded north of Prattsville to create New York City's Schoharie Reservoir and the Blenheim Gilboa Power Project. The Erie Canal crossed over the creek by an aqueduct at Schoharie Crossing State Historic Site. Two notable bridge collapses have occurred on Schoharie Creek. In 1987, two spans of the New York State Thruway collapsed. On August 28, 2011, the covered Old Blenheim Bridge collapsed due to flooding from Hurricane Irene.

Schoharie Creek is part of the drainage system of the Hudson River watershed and a direct tributary of the Mohawk River. Tributaries of Schoharie Creek, listed from upstream to downstream, include:

Before European colonization, the watershed was mostly forested with a few small areas cleared by Native Americans for hunting. Early European settlers attempted to farm the land, but soon abandoned it due to the short growing seasons, steep slopes and rocky soil. Between 1800 and the early 1900s, mills, the tanning industry, quarrying for bluestone, logging, railroads, and resorts cleared the Catskills of most of its forest cover. Starting in the early 1900s, these industries began to decline and areas that were previously cleared have grown back into forest. As of 2001, approximately 85% of the Schoharie Creek's watershed has been classified as forested.

New York's Department of Environmental Conservation (DEC) rates the water quality of Schoharie Creek in different sections. The section from Cobleskill Creek to Pleasant Valley Brook is rated Class C, which is most suitable for fishing, but can also be suitable for primary and secondary contact recreation. Stream flow on the lower Schoharie is significantly influenced by the Schoharie Reservoir. Flow from the reservoir is restricted when the dam is not open, and the lack of flow mostly during the summer increases water temperature, which negatively affects the fishery. Also this section flows through an agricultural valley, which contributes to increased sediment in the creek. This increases streambank erosion and sediment loadings, and during high flows, cause the creek's turbidity to increase. Biological tests were conducted in Fort Hunter in 2001, then in Burtonsville in 2001, and showed non impacted water quality conditions at both sites. Another station by Prattsville in operation since 1902, 0.2 mile (0 km) upstream from Schoharie Reservoir, had a maximum discharge of per second on August 28, 2011, with no minimum discharge recorded. Below the Schoharie Reservoir is the station by Gilboa in operation since October 1975, 0.5 mile (1 km) downstream from the Schoharie Reservoir dam, had a maximum discharge of per second on August 28, 2011, and a minimum discharge of per second on many days from June to October 1976, and September 11 13, 1980. Another station by North Blenheim in operation continuously since October 1970, 1.2 mile (2 km) upstream from bridge on State Highway 30 in North Blenheim, had a maximum discharge of per second on August 28, 2011, and a minimum discharge of per second on many days from June to October 1976, and September 11 13, 1980. Further downstream the station by Middleburgh in operation from July 1927 to September 1939 and since December 2017, slightly downstream of the bridge at intersection of State Highways 30 and 145 in Middleburgh, had a maximum discharge of per second on March 18, 1936, and a minimum discharge of per second on September 1, 1939. Outside the period of record, it had an estimated maximum discharge of per second on August 28, 2011. The station in Schoharie is located upstream from bridge on County Highway 1A has been in operation since December 2017, takes gauge height measurements only. It had a maximum gauge height of 13.42 feet (4 m) on August 14, 2018 and a minimum gage height of 4.47 feet (1 m) on many days between September 22 and October 1 in 2019. The station in Esperance is located by the US Route 20 bridge has been in operation since December 2017, takes gauge height measurements only. It had a maximum gauge height of 10.85 feet (3 m) on April 15, 2019 and a minimum gage height of 0.78 feet (0 m) on July 22, 2018. Outside the period of record, the flood of August 2011 reached a stage of 33.70 feet (10 m) from floodmark. The station in Burtonsville in operation since October 1939, 15 mile (24 km) upstream from the mouth, had a maximum discharge of per second on August 29, 2011, and a minimum discharge of per second on September 24–25, 1964.

The USGS station along the creek near Burtonsville, collects turbidity data every 15 minutes. The maximum daily suspended sediment concentrations (SSC) mean was 1460 mg/L on June 14, 2013, and the minimum was 2 mg/L on October 1–2, 2014. On June 14, 2013, the maximum daily suspended sediment discharge was 48,400 tons on June 14, 2013, and .16 tons on October 1–2, 2014. At the time, the creek was higher and flowing faster than normal due to excessive rains in the area. Twelve hours before the Schoharie Creek Bridge collapsed due to heavy rainfall, the rush of water through the Blenheim Gilboa Pumped Storage Power Project 40 mile (64 km) upstream hit a historic high. To cope with the overload, the dam released water into the Schoharie Creek according to the rate at which it was entering the reservoir from upstream, adding to the load in the creek. The segment of NY 5S near Fort Hunter was reconfigured to carry westbound Thruway traffic while the bridge was rebuilt. The eastbound replacement bridge was completed and fully open to traffic on December 7, 1987, and the westbound replacement bridge was opened on May 21, 1988.

The Old Blenheim Bridge, one of the longest and oldest single span covered bridges in the world, formerly spanned the creek. The bridge was destroyed on August 28, 2011 by flooding resulting from Hurricane Irene.