Shawangunk Kill

SIGNIFICANT HABITATS AND HABITAT COMPLEXES
OF THE NEW YORK BIGHT WATERSHED

I. SITE NAME: Shawangunk Kill

II. SITE LOCATION: The Shawangunk Kill is a tributary of the Wallkill River whose headwaters originate on the east slope of the Shawangunk Ridge. It is located in the Wallkill River valley and runs along the base of the east slope of the Shawangunk Ridge about 20 kilometers (12.4 miles) west of the Hudson River, and about 100 kilometers (62 miles) northwest of New York City.

TOWNS: Crawford, Gardiner, Shawangunk

COUNTIES: Orange, Ulster

STATE: New York

USGS 7.5 MIN QUADS: Pine Bush, NY (41074-53), Gardiner, NY (41074-62), Naponoch, NY (41074-63)

USGS 30 x 60 MIN QUAD: Monticello, NY-PA (41074-E1)

III. BOUNDARY DESCRIPTION AND JUSTIFICATION: The boundary of the Shawangunk Kill significant habitat complex includes its lower 29 river kilometers (18 river miles) segment from the village of Pine Bush downstream to its junction with the Wallkill River; a buffer of one kilometer (.62 mile) on either side of the kill is incorporated into the boundary designation. The boundary also includes the Dwaar Kill from the village of Dwaarkill downstream to its junction with the Shawangunk Kill and the grasslands and wetlands in and adjacent to the Galeville Army Airport. This boundary is intended to encompass the regionally rare animal and plant populations associated with the river and a buffer zone to protect the river corridor.

IV. OWNERSHIP/PROTECTION/RECOGNITION: The lands and waters of the Shawangunk Kill are generally privately owned, except for small parcels owned by the towns and one small parcel owned by Ulster County near the junction with the Wallkill River. The Galeville Army Airport located just east of the Shawangunk Kill is presently owned by the U.S. Department of the Army, which has recently indicated its intention to divest itself of this property. The stretch of the river between Red Mills and the confluence with the Wallkill River has been designated as a Recreational River under the New York State Wild, Scenic, and Recreational Rivers Act. Wetlands are regulated in New York under the state's Freshwater Wetlands Act of 1975 and Tidal Wetlands Act of 1977; these statutes are in addition to federal regulation under Section 10 of the Rivers and Harbors Act of 1899, Section 404 of the Clean Water Act of 1977, and various Executive Orders.

V. GENERAL AREA DESCRIPTION: The Shawangunk Kill originates in the town of Greenville and flows in a northeasterly direction, paralleling the Shawangunk Ridge for much of its length, before turning to the east and joining the Wallkill River; its total length is about 56 kilometers (35 miles). The Kill drains a watershed of about 380 square kilometers (147 square miles). The Shawangunk Kill is a free-flowing, relatively unpolluted river that has minimal development in the riparian corridor. The segment of the Kill downstream of Pine Bush has a gentle gradient, dropping an average of about 1.9 meters per kilometer (10 feet per mile). The river bed varies from solid bedrock to gravel, sand, and clay, with numerous boulders. The Shawangunk Kill has steep, high banks from 1.5 to 2.5 meters (4 to 8 feet). The average annual discharge of the Kill at Pine Bush is 3.9 cubic meters per second (138 cubic feet per second), and the average summer discharge is 2.0 cubic meters per second (72 cubic feet per second). The Shawangunk Valley is part of the Appalachian Ridge and Valley physiographic province, lying between the Shawangunk Ridge on the west and the much lower Hoagerburg Ridge on the east; it is a broad, gently rolling valley with open fields devoted to agriculture. The banks and islands of the Shawangunk Kill are generally vegetated with deciduous trees and shrubs. There are a few small mature floodplain forests along this stretch of the Shawangunk Kill. The underlying bedrock is predominantly shale, covered by generally poorly drained, silty loam soils of glacial origin. The water in the Shawangunk Kill is relatively cool and neutral to alkaline.

VI. ECOLOGICAL SIGNIFICANCE/UNIQUENESS OF SITE: The Shawangunk Valley habitat complex supports 29 species, including the following federally and state-listed species. (Living resources and their habitats are dynamic; therefore, the ecological significance and species information presented here may not be complete or up-to-date. State and federal environmental agencies [see Appendix III for office contacts] should be consulted for additional information.)

Federal species of concern⁽¹⁾swollen wedge mussel (Alasmidonta varicosa)

¹Species of special concern listed here include former Category 2 candidates.

State-listed endangered
pointed watermeal (Wolffia papulifera)

State-listed threatened
northern harrier (Circus cyaneus)
wingstem (Verbesina alterniflora)

State-listed special concern animals
wood turtle (Clemmys insculpta)
short-eared owl (Asio flammeus)
Henslow's sparrow (Ammodramus henslowii)

State-listed rare plants
Bush's sedge (Carex bushii)
Davis' sedge (Carex davisii)
red-rooted flatsedge (Cyperus erythrorhizos)
blunt spikerush (Eleocharis obtusa var. ovata)
violet bush clover (Lespedeza violaecea)
threadfoot (Podostemum ceratophyllum)
swamp agrimony (Agrimonia parviflora)
sharp-winged monkeyflower (Mimulus alatus)

The Shawangunk Kill is a relatively undisturbed Hudson River tributary. Its low nutrient levels, cool water, and lack of a major water control structure allow the lower Shawangunk Kill to support a regionally rare biological community. This stretch of stream supports high diversities of fish and mussels, unusual for the Hudson Valley. Six species of freshwater mussels have been identified in this stretch of the river, including the globally rare swollen wedge mussel and other unionid mussels including eastern elliptio (Elliptio complanata), eastern floater (Anodonta cataracta), triangle floater (Alasmidonta undulata), squawfoot (Strophitus undulatus), and eastern lampmussel (Lampsilis radiata). River fingernail clam (Spaerium fabale) has also been found in this stretch. Thirty-one species of fish have been reported from this segment of the river, including the following rare species: comely shiner (Notropis amoenus), sand shiner (Notropis stramineus), logperch (Percina caprodes), redbreasted sunfish (Lepomis auritus), and margined madtom (Noterus insignis). Wood turtle occurs in riparian habitat of the Shawangunk Kill and its tributaries. The federal candidate bog turtle (Clemmys muhlenbergii) has been found in several wetlands and tributaries of the Shawangunk Kill, but none of these populations has been located in recent years. The Shawangunk Kill supports the only known occurrence of beakgrass (Diarrhena obovata) in the state and in the study area. Rare plants of the Shawangunk Kill corridor include threadfoot found on submerged bedrock ledges in the river; sharp-winged monkeyflower, wingstem, and red-rooted flatsedge along the silty banks of the river; and beakgrass, Davis' sedge, swamp agrimony, small white aster (Aster vimineus), and violet bush-clover in old fields and open woods in the floodplain.

The Galeville Army Airport site adjacent to the Shawangunk Kill supports or has recently supported several rare or declining grassland bird species, including Henslow's sparrow, northern harrier, short-eared owl, long-eared owl (Asio otus), and rough-legged hawk (Buteo lagopus). Other grassland-nesting birds likely use this site as well. Rare plants found in the wetlands on the Galeville property include Frank's sedge (Carex frankii), Bush's sedge, small white aster, swamp agrimony, coontail (Ceratophyllum echinatum), and pointed watermeal.

VII. THREATS AND SPECIAL PROBLEMS: Excessive groundwater withdrawals could have significant impacts on flow and water quality. Water withdrawals from the Shawangunk Kill would be detrimental to the rare species found there. Longer low flow periods would result in increased warming of the water, reduced dissolved oxygen, increased concentration of nutrients and silt, and changes in the patterns of sediment deposition. Other threats include pollution by landfill leachate, withdrawal of water for irrigation, and siltation from logging, construction, and agriculture. Development in the watershed will likely have negative impacts on both the rare biological communities and downstream water quality. Clearing of vegetation adjacent to the river for agriculture, development, or forestry would threaten riparian communities and water quality.

VIII. CONSERVATION RECOMMENDATIONS: Further development or agricultural use should strictly limit encroachment within at least 300 meters (984 feet) of the river. Agencies and conservation organizations should work with farmers and landowners to improve streambank buffering through streambank fencing, plantings of shrubs and trees, and other methods. Agreements and easements should also be developed with farmers to delay the first cutting of hay to avoid impacts on grassland-nesting birds. The local communities along this stretch of the river should develop a regional plan to reduce impacts on the Shawangunk Kill. More complete studies of the flora and fauna of this stretch of the river, as well as of other locations in the upper Shawangunk Kill and other locations in the Wallkill River valley, are needed. Additional surveys need to be conducted for bog turtle in the Shawangunk Kill watershed and, if bog turtle are found, networks of habitat should be protected and restored. The Galeville Army Airport site should be transferred to a federal, state, or local agency that will manage it for the protection and enhancement of grassland and wetland habitats and species.

IX. REFERENCES:

Barbour, S. and G. Stevens. 1994. Rare plants survey of the Shawangunk Kill corridor. Report to the Shawangunk Valley Conservancy. Hudsonia, Ltd., Annandale, NY.

Domville, M. and Dunbar, H.F. 1970. The flora of Ulster County, New York. John Burroughs Natural History Society Bulletin no. 8. 136 p.

Kiviat, E. 1991. Shawangunk Kill biodiversity and impacts of the proposed Orange County water diversion. Report to Shawangunk Valley Conservancy. Hudsonia, Ltd., Annandale, NY.

Kiviat, E. 1991. The Shawangunk Kill, Hudson Valley natural area. News from Hudsonia, Bard College Field Station, Annandale, NY.

New York State Department of Environmental Conservation. 1993. Proposal to establish final river corridor boundaries, Shawangunk Kill Recreational River. Division of Lands and Forests, New Paltz, NY.

Schmidt, R. and Kiviat, E. 1989. Shawangunk Kill biology and the proposed water withdrawal, Ulster and Orange Counties, New York. Hudsonia, Ltd., Bard College Field Station, Annandale, NY. 24 p.

Shawangunk Valley Conservancy. 1980. Report on the natural, historic, and economic resources of the valley of the Shawangunk Kill, Ulster County, New York.

Stevens, G. 1992. Wetlands on the Galeville Army Training Site, Report to the United States Military Academy (West Point). Hudsonia, Ltd., Bard College Field Station, Annandale, NY.

Strayer, D. 1987. Ecology and zoogeography of the freshwater mollusks of the Hudson River basin. Malacological Review. 1987(20):1-68.

List of Species of Special Emphasis

Maps

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