The West Kill, an tributary of Schoharie Creek, flows through the town of Lexington, New York, United States, from its source on Hunter Mountain, the second-highest peak of the Catskill Mountains. 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. It lends its name to both a mountain to its south and a small town midway along its length.
The West Kill's watershed accounts for 10 percent of the reservoir's basin. It has the highest elevations and steepest slopes of any of the Schoharie's subwatersheds, with runoff from seven of the 35 Catskill High Peaks draining into the stream. Due to limited development and extensive land protection in the stream's watershed, its water is relatively clean, supporting a habitat for both wild and stocked trout; historically it has drawn fly fishers and other anglers. However, the West Kill has contributed to turbidity issues with the Schoharie creek and reservoir due to recent floods; several government agencies have worked together to develop a management plan that will mitigate the floods and the turbidity.
Course
The upper of the West Kill flows west through the Spruceton Valley to the hamlet of West Kill. From there it turns to a more northerly course to the Schoharie at Lexington.
Spruceton Valley
Two streams that later join rise in the cirque between Hunter and Southwest Hunter mountains, amidst the dense forests of the West Kill Wilderness Area, part of the Catskill Park. The source of the northern stream is at , the higher of the two. It flows through a narrow groove down the steep upper slopes of the cirque for its first quarter-mile (400 m).
Just under in elevation, the terrain becomes gentler. At the town line between Hunter and Lexington, the two streams join. The West Kill flows steadily downhill for its next half-mile (800 m) as the Devil's Path hiking trail, itself descending the mountain, gradually comes closer to the stream and follows it along its north side.
At Diamond Notch Falls, the Devil's Path merges briefly with the Diamond Notch Trail coming in from the west. The two cross the West Kill on a wooden bridge, the uppermost crossing of the stream. Just south of the stream, the trails again diverge, with the Devil's Path following the stream for a short distance on that side before beginning its ascent of West Kill Mountain to the southwest. The Diamond Notch Trail runs parallel to the kill for another to the trailhead parking lot, the eastern end of Greene County Route 6, known locally as Spruceton Road, at elevation.
Shortly after that, the valley begins to widen slightly. The West Kill receives its first tributary, an unnamed stream that flows into it from the slopes of the eponymous mountain to its south. West of that confluence the kill begins to pass some cleared areas and structures. As Spruceton Road bends to the north away from the stream, its first named tributary, Hunter Brook, flows in from the north just east of where Spruceton Road crosses. After receiving Pettit Brook from the south, Spruceton Road returns to the north side of West Kill.
Privately owned Wolff Road crosses the West Kill beyond. A half-mile further west, a short local street, Ad Van Road, crosses. Just below, at the former hamlet of Spruceton, Herdman Brook flows into the West Kill from the slopes of Evergreen Mountain to the north. Styles Brook follows shortly, draining the cirque below West Kill Mountain's summit, from the south, just west of where Baker Road crosses to provide access to several farms on that side. Cleared fields and structures are now found on both sides of the stream.
Another further west, the kill again crosses under Spruceton Road. The road and stream meander west another mile (1.6 km), never getting very far from each other, as the West Kill receives more unnamed tributaries from the mountains to the north and south. Auffarth and Tumbleweed Ranch roads cross the kill along this stretch.
After returning to the south side of Spruceton Road, the West Kill receives Hagadone Brook from the valley on its south, between the two ridges on the north face of North Dome. Schoolhouse Brook flows in from the north further west. Shoemaker Road, providing access to several properties on the stream's south side, crosses east of where Bennett Brook flows in from the south.
Long Road crosses over the West Kill 0.6 mile (1 km) downstream, just above where Newton Brook flows down from a valley on the slopes of Mount Sherrill to the south. After following Spruceton Road closely for an equivalent distance, the stream crosses under it for the last time. As the West Kill reaches the similarly named hamlet, it descends under in elevation.
Below West Kill hamlet
As the West Kill passes north of West Kill, at first flowing right behind some of the hamlet's houses, it begins to turn toward the northwest as it widens briefly through an area with several bars. After the stream narrows again, it returns more to the west-northwest to flow under New York State Route 42. About beyond the bridge, it veers back to north-northeast, then north-northwest again, paralleling the highway. Through this stretch it receives three unnamed tributaries from the west, all rising from the slopes of the unnamed mountains northwest of Deep Notch.
At a bend in the stream a mile (1.6 km) north of West Kill, where the Shandaken Tunnel's visible surface right-of-way, along with a power line, cross the kill twice, Beech Ridge Brook flows in from the west. Immediately north of the bend, the West Kill crosses under Route 42, entering a section where both banks are shored up with riprap for the next as the stream and road again follow a north-northeasterly course. The natural banks return where Roarback Brook, the lowest tributary of the West Kill, flows in from slopes of Vly Mountain to the west.
After a mile (1.6 km), the West Kill crosses under Route 42 for the last time just west of the hamlet of Lexington. Shortly afterwards, it turns east then slightly east-southeast to its mouth at Schoharie Creek. At this point it has descended to just above in elevation.
Watershed
The West Kill's watershed, accounting for 10 percent of the total Schoharie Reservoir watershed, is, like the stream itself, predominantly in the town of Lexington. Its eastern area, where the stream rises, is in Hunter, and some of the uppermost areas where its lower western tributaries arise are in another neighboring town, Halcott. Ridgelines between the mountains on either side form the watershed's boundaries except for the area around its mouth at Lexington.
On the north side Rusk Mountain and the peaks to its west form the boundary between the West Kill watershed and the Schoharie's. South of the range from Southwest Hunter Mountain to Mount Sherrill drainage flows into Esopus Creek, another Hudson tributary in Ulster County. The unnamed peaks over in elevation between Halcott and Vly mountains on the southwestern boundary are part of the Catskill Divide, since the Vly Creek basin on the opposite side is part of the Delaware River watershed. On the northwest is the smaller watershed of the Little West Kill, another Schoharie tributary.
The highest point in the West Kill watershed is the approximately summit of Hunter Mountain, also the highest point in the Schoharie and Mohawk watersheds. As a whole the watershed has the highest overall elevation of any subwatershed within the Schoharie basin. It also boasts the steepest average slope, at 29 percent, with a drainage density of 0.0013 m/m, lower than average for the Catskills.
Within the watershed, the predominant land use is open space. Almost two-thirds of the land, , is deliberately undeveloped, much of it in forested lands on the mountains, most of which are protected area managed by the state Department of Environmental Conservation (DEC). Most of the watershed is within New York's Catskill Park, where the state constitution requires that land owned by the state be kept "forever wild" as part of New York's Forest Preserve.
Most of the forest in the watershed is deciduous, accounting for nearly three-quarters of the watershed's total land cover. These woodlands are mostly the beech-birch-maple northern hardwood forest that covers much of the Catskills. The next largest amount is coniferous forest at 14 percent, most of it in the montane spruce-fir boreal forest that grows on the higher-elevation mountain summits and the ridges between them, with some remaining Eastern hemlock stands and reforested areas of Norway spruce also included. Mixed forests, including areas where the deciduous forest is transitioning to coniferous on mountain slopes, accounts for another 11 percent of cover, and grass in open fields is 2 percent of the total.
Water covers ; the National Wetlands Inventory maintained by the U.S. Fish and Wildlife Service has identified 79 separate wetlands within the West Kill watershed, totaling , including all open water. While the largest portion is the stream itself, about 54 percent of the total acreage is palustrine wetlands such as marshes and swamps. Only of the basin is covered with impervious surfaces like road pavement (the watershed has a road density of of road per of land area).
After open space, low-density and vacant residential use accounts for most of the remaining land in the watershed, at 33.3 percent. Agriculture, most of it the raising of livestock, accounts for 2.6 percent. Hotels come in at 0.7 percent.
History
Before European colonization, it is possible that the Iroquois and other Native American peoples who lived in the Catskill region might have explored the West Kill valley. But there is no evidence that they did, and they did not settle in the mountains due to their low-quality farmland, preferring the richer soils closer to the rivers. If they did venture into the Catskills, it was to travel across them, hunt or practice religious rituals.
Even when Europeans came, settlers did not go to the West Kill valley. It was surveyed, and lot lines were drawn up as part of the 1708 Hardenburgh Patent, the land grant that marks the formal beginning of European land ownership in the Catskills. There is no record of anyone living in the current boundaries of the town of Lexington before independence. Robert R. Livingston, whose family had traded shares of the patent and eventually came to own half of its two million acres (), leased one lot in the town in 1777, but it is not known whether the lessee chose to live there.
The earliest known settler in Lexington was a man named Dryer, who used the West Kill's waterpower to operate a woolen factory in 1780. Some other settlers, the first inhabitants of the hamlet of West Kill, were also reported as having moved in around the same time. Others followed quickly, drawn by the promise of abundant furs and timber on land that was still cheap. In 1813 Lexington was separated from Woodstock into the present town.
How much of this early growth took place along the West Kill is uncertain. In his 1813 gazetteer of the state as it was at the time, Horatio Gates Spafford (who described Lexington under Windham) describes the Schoharie and the Batavia Kill, which empties into it upstream from Lexington, as already supporting many rapidly-built mills. He does not mention the West Kill, which, while some other accounts also report similar milling operations along it, may also indeed have been comparatively undeveloped at that time.Ravage, pp. 18–38; accessed June 10, 2020