Schoharie Creek


Schoharie Creek in New York, flows north 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.
During the American Revolutionary War, Iroquois Indian attacks against the cluster of farms in the valley of the Cobleskill Creek tributary was the site of the Cobleskill Massacre, virtually depopulating settlements in the southern Mohawk valley. News of this and two other mixed Tory-Indian guerrilla attacks lead to an appropriation of funds for the Sullivan Expedition dispatched by General Washington in 1779 to break the threat of Indian raids.
The Erie Canal crossed over the creek by an aqueduct at Schoharie Crossing State Historic Site.
Two notable bridge collapses have occurred on the 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.

Geography

Watershed and tributary streams

Schoharie Creek is part of the drainage system of the Hudson River watershed and a direct tributary of the Mohawk River. It has the sister-tributaries: Alplaus Kill, Plotter Kill, North Chuctanunda Creek, South Chuctanunda Creek. These regional streams are tributaries of Schoharie Creek :
Right
Gooseberry Creek

Red Kill

East Kill

John Chase Brook

Batavia Kill

Hunterfield Creek

Platter Kill

Keyser Kill

Little Schoharie Creek

Stony Brook

Fox Creek

Bowman Creek
Left
Roaring Kill
Cook Brook

West Kill

Little West Kill

Johnson Hollow Brook

Bear Kill

Mine Kill

West Kill

Cole Brook

Panther Creek

Pleasant Valley Creek

Line Creek

Cobleskill Creek

Cripplebush Creek

Fly Creek

Wilsey Creek

Irish Creek

Hydrology

Water quality

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.

Discharge

The United States Geological Survey maintains stream gauges along Schoharie Creek. The station in Burtonsville, upstream from the mouth, had a maximum discharge of per second on August 29, 2011, as Hurricane Irene passed through the area, and a minimum discharge of per second on September 24–25, 1964. The station by Breakabeen, downstream from Keyser Kill, had a maximum discharge of per second on August 28, 2011, and a minimum discharge of per second on October 14, 1988. Another station by Gilboa, upstream from Platter Kill, had a maximum discharge of per second on August 28, 2011, and a minimum discharge of per second on most days between June and October 1976 and September 11–13, 1980. Another station, east of Lexington, had a maximum discharge of per second on August 28, 2011, and a minimum discharge of per second on August 21–22, 2002.
The valley the creek flows through is equipped with a flood warning system. A combination of sirens throughout the valley and a “reverse 911 system” where residents receive telephone warning when severe floods are likely to occur. The warnings are based on stream gage readings along the creek and its tributaries.

Turbidity

The USGS station along the creek near Burtonsville, collects turbidity data every 15 minutes. The maximum daily suspended sediment concentrations 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.

Historic Schoharie

In the 18th century, areas of the south side of Mohawk Valley were sparsely settled in the face of the periodically warlike and always militant Iroquois peoples, who, while diminished by European diseases during colonial times still retained ample war powers after the French and Indian War ended in 1763. Reorganized by then as the Six Nations the tribes had conducted internecine war with other powerful eastern tribes until the 1770s, weakening or eliminating the power of the Delaware, the Susquehanna, and Shawnee tribes— affecting Amerindian populations and power both East and West of the Alleghenies as far south as northern Kentucky in the west, and southern Maryland in the east. By the end of the French and Indian War, they were the one remaining group of eastern native peoples that retained sufficient military power to give even the British authorities pause. Consequently, those authorities cultivated political arrangements with the Iroquois and as a prelude to the revolution, the British Crown acted to block trans-Appalachian settlements before the opening of the American Revolution, one of the lesser known grievances of many held by the settlers.

During the Revolution, farms in the valley acted as a breadbasket providing important food supplies to the Colonial forces. The lower Mohawk valley was a scene of uneasy native Amerindian-Colonial Settler contention throughout most of the 18th century until after the American Revolutionary War's Sullivan Expedition pacified the region by permanently weakening the Six Nations of the Iroquois. That campaign was a direct result of two atrocities in the region: The May 1778 Battle of Cobleskill signaled a new guerrilla war offensive by mixed troops of Loyalists and members of the four Iroquois tribes allied to the British in 1778. The incursions resulted in three major raids with major loss of life ranging from Southern New York to Wilkes-Barre, Pennsylvania.

Old Blenheim Bridge

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.

New York State Thruway bridge collapse

On the morning of April 5, 1987, after 30 years of service, two spans of the New York State Thruway bridge over the Schoharie Creek near Fort Hunter collapsed. Five vehicles fell into the flooded river, ten of the occupants died. A subsequent investigation of the collapse determined the cause to be scour.
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.