East Kill

East Kill
Location of mouth within New York East Kill (the United States)
Location
Country	United States
State	New York
County	Greene
Physical characteristics
Source
• coordinates	42°13′50″N 74°04′29″W
Mouth	Schoharie Creek
• location	Jewett Center, New York, United States
• coordinates	42°14′11″N 74°19′09″W
• elevation	1,381 ft (421 m)
Length	16 mi (26 km)
Basin size	36.3 sq mi (94 km2)
Discharge
• location	Jewett Center
• minimum	0.84 cu ft/s (0.024 m3/s)
• maximum	28,400 cu ft/s (800 m3/s)
Basin features
Tributaries
• right	Halsey Brook, Roaring Brook

East Kill, a 16-mile-long (26 km) tributary of Schoharie Creek, flows across the town of Jewett, New York, United States, from its source on Stoppel Point. Ultimately its waters reach the Hudson River via the Mohawk. Since it drains into the Schoharie upstream of Schoharie Reservoir, it is part of the New York City water supply system.

Course

East Kill starts as a mountainous stream dropping approximately 780 feet (240 m) in its first mile, then reduces in slope to dropping about 200 feet (61 m) over the next mile. The remainder of the creek drops to an average slope of 42 feet (13 m) per mile until it reaches its confluence with Schoharie Creek.

Watershed

The East Kill's 36.25-square-mile (93.9 km²) watershed, is mostly located within the town of Jewett, with a few small sections entering into the towns of Windham, Ashland, and Lexington.

Within the watershed, the predominant land cover is undeveloped forested area, at 20,808 acres (32.513 sq mi) or 90 percent of the watershed. About 2.5 percent of the watershed is developed and the remaining 7.5 percent is shrubland.

Water covers 104 acres (42 ha); the National Wetlands Inventory maintained by the U.S. Fish and Wildlife Service has identified 168 separate wetlands within the East Kill watershed, totaling 311 acres (126 ha), including all open water. About 84.5 percent of the total acreage is palustrine wetlands such as marshes and swamps.

The highest point in the East Kill watershed is 3,948 feet (1,203 m) at the summit of Black Dome Mountain in southeast Jewett. The average elevation of the watershed is approximately 2,674 feet (815 m).

Geology

While the Catskills originated during the Devonian period, around 375 million years ago, as a former river delta uplifted and became a dissected plateau, the East Kill's valley was formed during the recent effects of the Wisconsin glaciation, which ended about 12,000 years ago. Meltwater fed many streams, which eventually formed today's East Kill.

Lodgement till, which is a very dense, clay-rich, and reddish brown deposit, is very frequent in the East Kill and upper Schoharie Creek watersheds. The extreme density is distinguished from the looser assemblage of mixed sediment that comprises melt-out till found in moraines and along mountain sides. The presence of bedrock banks in the East Kill can represent natural limits to changes in the stream channel system. Examples of this are shown in the headwater waterfalls.

Hydrology

The East Kill's watershed receives an average 44 inches (1,100 mm) of precipitation annually, making it one of the wettest areas of the Catskills. Most of the precipitation is concentrated in seasonal events such as summer thunderstorms, remnants of hurricanes later in the year, or rain-on-snow events in springtime. The average slope of the watershed is 17.3 percent. Drainage density, or how much stream length is available to carry water off the landscape, is slightly higher than average streams in the Catskills. The high average drainage density, steep slopes, and high precipitation causes flash floods during storm events. However, most of the watershed lies within forests that tend to mitigate this somewhat.

Discharge

The United States Geological Survey (USGS) maintains stream gauges along East Kill. The station on Mill Hollow Road, 1.3 miles (2.1 km) northeast of Jewett Center, had a maximum discharge of 28,400 cubic feet (800 m³) per second on August 28, 2011, as Hurricane Irene passed through the area, and a minimum discharge of 0.84 cubic feet (0.024 m³) per second on August 13, 1997.

Water quality

NYSDEC performed a study of the creek in 2005 and 2006, showed that overall water quality was good. Also it showed that aquatic life was normal in the stream, and that there were no other water quality impacts to recreational uses. In the past, there has excessive stream bank erosion along the creek. However the East Kill does not seem to be as prone to sediment and turbidity problems like other Schoharie Creek tributaries in the area. However, sediment load from East Kill, along with West Kill and Batavia Kill, have been the principal contributors of sediment and turbidity in the Schoharie Reservoir.

DEC rates the water quality of the stream as Class C, suitable for fishing and non-contact human recreation. The agency also adds a "(TS)", indicating that the stream's waters are ideal for trout spawning. The kill's waters are pure enough to be part of the New York City water supply system; after draining into the Schoharie they are impounded at Schoharie Reservoir downstream, where they can be delivered through the Shandaken Tunnel to Esopus Creek at Shandaken. From there they go to Ashokan Reservoir, which supplies 10 percent of the city's water, and then, via the Catskill Aqueduct, to customers, without requiring filtration.