Ten Mile RiverTenmile River


"The beauty and unspoiled appearance of the Tenmile River, where there is no visible human impact, is breathtaking. This basin is a pristine river system that has been extolled by fishermen and developers alike. It is compact and accessible and is a resource for recreation, hiking, fishing and swimming... The water that is stored in the ground and that flows through the streams is the only source of drinking water for the region. And we have great drinking water here. It is therefore extremely important that this valuable resource which is facing so many local environmental impacts be preserved. The quiet and remote beauty of the Tenmile River watershed area is the very reason that it is so desirable..."

-from a presentation given by Tonia Shoumatoff, Housatonic Valley Association Watershed Manager for the Ten Mile, on 8/22/2008

General info

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The watershed of the Tenmile River is approximately 210 square miles in size and covers roughly 25% of Dutchess County on its eastern border. The river runs predominately north to south, is approximately 33 miles long and unlike the other major watersheds in Dutchess County, empties into the Housatonic River in Gaylordsville, CT. Towns and Villages within the watershed include:

Dutchess County

  • Northeast
  • Pine Plains
  • Village of Millerton
  • Stanford
  • Amenia
  • Washington
  • Dover
  • Unionvale
  • Beekman
  • Town of Pawling
  • Village of Pawling

Columbia County

  • Ancram

Litchfield County, Connecticut

  • Sharon
  • Salisbury
  • Kent
    Major tributaries of the Tenmile include the Wassaic Creek, which lies in the western portion of the watershed, the Webatuck Creek, which lies in the eastern portion of the watershed, and the Swamp River, which is located in the southern end of the watershed and flows north into the Tenmile River.

    Subwatersheds within the Tenmile River include:

    • Webatuck Creek
    • Swamp River
    • Tenmile River
    • Wassaic Creek
    • Beaver Brook
    • Doctors Brook
    • Butts Hollow Brook
    • Stone Church Brook
    • Seven Wells Brook
    • Mill River
    • Stony Brook
    • Burton Brook
    • Deuel Hollow Brook

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    Land Use History

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    The area is referred to as the Harlem Valley and is experiencing rapid growth. Land use is predominantly agricultural with residential development increasing. Route 22 and 6 follow the river in several locations.


    Click on the map to ses a larger high- resolution PDF version.
    The Tenmile watershed is located near the edge of the Taconic Mountains, an area of extremely complex geology that has puzzled and frustrated generations of geologists. Most of the rocks in the valleys consist of the Stockbridge formation, a collection of early Paleozoic marbles, limestones, and schists, originally deposited in a tropical sea known to geologists as the Iapetus Sea. A complex group of dark colored erosion resistant rocks that were deposited originally as sedimentary rocks along the shores of the Iapetus Sea form high ridges above the carbonate valleys of the watershed. These early Paleozoic intensely metamorphosed schists, slates, and gneisses which include the Everett formation and the Walloomsac formation were folded, faulted, and moved as enormous slabs many miles from where they formed by tectonic events known as the Taconic orogeny. Thrust faulting shoved older rocks on top of younger rocks and many eons of erosion have removed much of the rock record. The basement rocks, visible in the Amenia area, are Precambrian Grenville granitic gneisses that are part of the Housatonic Highlands and form erosion resistant ridges. Topping all of this is a mantle of glacial debris left by the melting of the Wisconsin ice sheet less than 20,000 years ago.

    Eons of erosion have resulted in a valley and ridge topography oriented mostly north-south along the eastern edge of Dutchess and Columbia counties in New York and adjacent New England. The less resistant carbonate rocks of the Stockbridge formation form the floors of wide valleys that are paralleled by ridges of highly metamorphosed erosion resistant rocks of the Everett and Walloomsac formations that rise as much as a thousand feet above the valleys.

    Approximately 15,000 years ago, the Wisconsin ice age waned in the area leaving behind extensive deposits of glacial till and outwash and other evidence including the overall “softening” of the contours of high ridges, a result of glacial ice overriding and burying everything in its path. Deeply incised valleys in the ridges that presently accommodate “under fit streams” provide evidence that they were cut by torrents of water from rapidly melting masses of ice. The many colorfully named “hollows” in the Harlem Valley such as Turkey Hollow and Deep Hollow are examples.

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    Wildlife and Fisheries

Mammals found in the Upland hardwood forests, open meadows, and wetland areas of the Ten Mile watershed include:*
  • Black Bear
  • Bobcat
  • Coyote
  • Eastern chipmunk
  • Eastern cottontail
  • Indiana Bat
  • Meadow Vole
  • Muskrat
  • Red fox
  • Red squirrel
  • River otter
  • Southern flying squirrel
  • White-footed mouse
  • White-tailed deer

Bird species in the Ten Mile watershed may include:*

Coopers Hawk.  Image from Cornell Lab of Ornithology, © maia bird, Rehoboth, MA, 2008.
Image of Coopers Hawk from the Cornell Lab of Ornithology, © maia bird, Rehoboth, MA, 2008.
  • Acadian flycatcher
  • American woodcock
  • Barred owl
  • Black-throated green warbler
  • Broad winged hawk
  • Brown creeper
  • Cerulean warbler
  • Cooper’s hawk
  • Dark-eyed junc
  • Great blue heron
  • Great horned ow
  • Pine Siskin
  • Purple finch
  • Red-breasted nuthatch
  • Reed shouldered hawk
  • Sharp-shinned hawk
  • Wood duck
  • Wood Thrush

For more information on common bird species found in the area, see the Cornell Lab of Ornithology online bird guide, at: http://www.allaboutbirds.org.

Common Fish species found in the Ten Mile Creek watershed include:*

  • Brook trout
  • Brown trout (stocked by the NYS DEC in the Ten Mile Creek)
  • Slimy sculpin
  • Wild Brook Trout (in small headwater streams)

Some of the amphibians and reptiles that may be found in the Ten Mile watershed include:*

A wood turtle, as can be found in the Ten Mile River watershed.
  • Eastern box turtle
  • Green frog
  • Marbled salamander
  • Northern dusky salamander
  • Northern two-lined salamander
  • Painted Turtle
  • Ribbon snake
  • Snapping turtle
  • Spotted salamander
  • Spotted turtle
  • Spring Peeper
  • Timber rattlesnake
  • Wood frog
  • Wood turtle (see picture)
* For further information on the significant habitats found in the Ten Mile River Watershed, and their associated species, see the Biodiversity Assessment Reports produced by Hudsonia, Ltd., at http://hudsonia.org/, particularly the Report “Significant Habitats in the Town of Amenia, Dutchess County, NY.” Annandale, NY: Hudsonia (2006).

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    Water Quality

    Most of the streams within Dutchess County are Class B, C, and D allowing swimming, fishing and boating respectively. In the Tenmile River watershed streams and lakes that are classified as A, for drinking water, include Ellis Pond, Swamp River, Hiller Brook (below dam), Pawling Reservoir, and Green Mountain Lake.

    The recent New York State Department of Environmental Conservation Waterbody Inventory and Priority Waterbodies List for New York Portion of the Housatonic Watershed(of which 82% is made up of the Ten Mile River Watershed) found the water quality to be "generally quite good." Any water quality impacts that were found came from agricultural nonpoint source pollution and were generally minor impacts "that stress or threaten rather than impair water uses." The only two waterbodies in this watershed that are listed on the Priority Waterbodies List are the Lower Swamp River and Rudd Pond, both listed as "aquatic life suspected of being stressed".

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    Public Access Sites

    Public Access Sites to Water Resources in Dutchess County

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    Public access sites in the Ten Mile River watershed
    Indicates a public access site on the Ten Mile River or a tributary to the Ten Mile River

    Public access sites in nearby watersheds
    Indicates a public access point to the Hudson River or a Hudson Direct drainage stream
    Indicates a public access site on the Fall Kill
    Indicates a public access site on the Casperkill
    Indicates a public access site on the Wappinger or a tributary to the Wappinger
    Indicates a public access site on the Fishkill Creek
    Indicates a public access site for the Roeliff Jansen Kill

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    Top Threats

  • Excessive erosion and sedimentation along areas of the Ten Mile Creek, leading to excessive flooding and loss of streambanks.
  • Loss of forested areas and increasing fragmentation due to increasing development, leading to loss of ecologically significant habitats.
  • Lack of Ten Mile River intermunicipal watershed cooperation.

Ten Mile River



  • Riverkeeper Presentation: Crude Oil Transportation in the Hudson Valley

    April 2nd

    Date: April 2, 2015: 5:30PM to 7:00PM
    Location: Vassar College, Poughkeepsie, Room TBA

    Join Riverkeeper’s Jeremy Cherson, Riverkeeper Fellow for a presentation about the risks of crude oil transportation in the Hudson Valley on April 2, 2015. This presentation is made possible by our sponsors the Casperkill Watershed Alliance and Vassar College Sustainability - See more at: http://www.riverkeeper.org/news-events/events/rvk-events/vassar-college-crude-oil-transportation-presentation/#sthash.lchhqX4M.dpuf