“Once upon a time a little stream began, clear and sweet, in a swamp where the green herons perched in the buttonbushes, and the marsh wrens nested in the long cattails. What this stream may have been called by the Wappinger Indians we do not know, but early Dutch settlers called it the Casperkill. Along its banks the mink and otter hunted and played, while the deer came through the forest to quench their thirst.”
- from Our Lovely Casperkill, by Dr. A. Scott Warthin, Jr., Professor of Geology, Vassar College (1965)
The swamp that gives life to the Casperkill is a wetland that can still be found in the Northeast corner of the Town of Poughkeepsie. A weather-beaten road presses through the wetland and low-lying valley so densely filled with plants that one cannot walk through it. At certain times of the year the plants stand in water; the valley acts as a thick sponge that absorbs rain and run-off from adjacent hills. The wetland maintains a steady supply of fresh water for the Casperkill. As the stream journeys to the Hudson River, it flows through a wide variety of land uses and local environments, including forested wetlands, commercial districts, the Vassar College campus, and both low and high-density residential neighborhoods. The water flowing into the Casperkill picks up traces of the land that it drains; all of these inputs influence stream health and often have detrimental impacts on the quality of water and its ability to provide ecosystem services.
The Casperkill watershed lies entirely within the boundaries of the Town and City of Poughkeepsie in Dutchess County, New York. Draining the watershed, the Casperkill stream flows for 11 miles from its headwaters at the base of Peach Hill Park to the Hudson River at the Tilcon Quarry and provides a unifying element to the Town of Poughkeepsie. It is joined by one major tributary, the Fonteynkill, on the Vassar College campus just south of the Sunset Lake dam. Together, these streams occupy a 12 square mile (7680 acre) watershed.
Casperkill Watershed Alliance
Since the spring of 2006, student and faculty researchers from Vassar College's Environmental Research Institute have conducted water quality monitoring of the Casperkill Creek Watershed on a monthly basis, assessing such parameters as the amount of road salt in the stream; dissolved oxygen, nutrient, bacteria, and heavy metal levels; stream water pH; the extent and species composition of streamside vegetation; and the state of aquatic organisms. Following outreach to the community, Vassar helped form the Casperkill Watershed Alliance, which meets regularly and organizes various community watershed events.
The Casperkill has a long and important history in the development of both the Town and City of Poughkeepsie. Arrowheads and other tools found at Bowdoin Park suggest that the Wapani Native Americans lived in the Poughkeepsie area for over 9,000 years before European arrival. They called the area where the creek meets the Hudson Thanackkonek, “the place of nut trees.” This area was abundant with beech, walnut, and chestnut trees. Further up the creek, the Wapani referred to the creek as Pietawickquasseick, meaning “the high lands at the end of the bog."
On June 2, 1688, the land between the Wappingers and Casperkill creeks was granted by five Wapani to Arnout Cornelissen Viele. The Schuyler Patent, which records the details of the exchange, includes the name of Pieter Lassen (“Pieter the Brewer”), who was the first European to secure permanent residence in Dutchess County. Lassen, a former indentured servant who arrived in New York in 1659, renamed the creek for his brother-in-law Jan Casperse Hallenbeck, who lived in Albany County. The Schuyler Patent thus references the creek by both its native names and as that waterway “knowne by the Christians for Jan Casperes Creek." Thus the creek once referred to by its geographical qualities was from thence forth called by a name honoring a man who never lived in the area.
In the late 17th century and throughout the 18th century, the creek continued to be referred to by both its native and its European names. As late as 1798, one map of the township of Poughkeepsie labeled the creek Thanakonok. The spelling and pronunciation of the European name changed continuously, and documents throughout European settlement refer to the creek variably as Jan Casper’s Creek, Jan Casperes Creek, Jan Casper’s Kil, Jan Casperses Creek, Casper Creek, Casperkill Creek, John Gaspe Kill, John Cospesing Kill, Kasper Creek, and Kaspar Creek. Today various people and agencies refer to the creek as either Casperkill Creek or the Casper Creek, either adding or dropping the Dutch suffix kill (meaning creek) from the title.
Since the time of Pieter Lassen’s settlement, the Casperkill has seen a great deal of activity. The place of Lassen’s settlement, on the southern side of the creek’s mouth at Clinton Point, became one of the most coveted parcels of land in the area. In 1804 Governor George Clinton bought the land at the mouth of the creek, hence the name Clinton Point that still distinguishes the area. From Clinton the “magnificently wooded” site was passed on to congressman James Talmadge (who has a street named after him in the City of Poughkeepsie), then to his daughter Mrs. Philip Van Rensselaer. She treated the site such that it was considered by some to be the “finest country seat on the Hudson.” The built and natural beauty of the area was not to last, as the New York Trap Rock quarry purchased the land in 1924. For the past three quarters of a century, the Tilcon-owned quarry has mined limestone from the 1,200 acre site, extending 175 feet below the level of the Hudson. According to a conversation between writer Reed Sparling and Trap Rock director Edmund Daddona, there is enough dolomite in the quarry to keep operations productive for another century.
Traveling upstream from Clinton Point, the rest of the creek has been subject to varying levels of development. At the turn of the 19th century, several mills were located on the creek, the remnants of which can be seen in features such as the manmade waterfall just upstream of the Rt. 9 intersection with the creek. Another large-scale project affecting the creek was the creation of Sunset Lake at Vassar College in 1915. Before the creation of the small lake, the College dumped its sewage directly into the creek. It was only after the installation of Sunset Lake that Vassar faculty member Ellen Swallow Richards proposed and designed a sewage treatment plant for the College.
Further upstream from Vassar College, the creek runs through the Route 44 Plaza on Burnett Boulevard Extension. Originally the site was a clay-saturated marshland until 1790 when it was converted into a brickyard. The brickyard was active for over a century, but in 1940 the land was leased to the Town of Poughkeepsie by John Van De Water and used as a municipal landfill from 1948 until 1971. Once the landfill closed, development began almost immediately on two shopping plazas: the Route 44 Plaza and the Dutchess Center Plaza. However, some of the methods employed during the repaving process were questionable and unchecked by EPA regulations, resulting in structural and ecological problems that persist today: potential leaking of methane gas, strong odors, and leaching of organic compounds into the surface and ground water of the Casperkill and the soil and sediment of the watershed. Although the clay in the site provides a barrier that prevents the majority of the leachate in the landfill from migrating to the creek, the history of land use and questionable construction practices may have caused, or at least contributed to, the ecological problems that the watershed continues to experience today. For more on the history of the 44 Plaza and Brickyard Hill, as well as maps and great references for further reading, see this paper by Lucy Robins.
Currently, the distribution of different land covers in the Casperkill watershed is variable, with some areas highly urbanized and others more natural. In the watershed as a whole, 43% of the land is forested, 33% is covered in impervious surfaces, and another 19% is classified as grass. The latter category includes open fields, lawns, and golf courses. The remaining 5% of the landscape consists either of water bodies (small ponds and lakes) or of fallow areas. The Tilcon quarry site is classified as impervious surface inasmuch as the runoff potential of bare stone is similar to that of paved surfaces.
The most urbanized part of the watershed surrounds the Fonteynkill tributary, which drains a portion of the City of Poughkeepsie. Here impervious surfaces constitute as much as 70% of the total landscape. The least urbanized stretches include the northernmost part of the watershed between Van Wagner Rd. and Peach Hill Park, the Vassar Farm and Ecological Preserve, and lands surrounding the Casperkill Golf Club. These areas have vegetated buffers along the stream channel that are largely intact.
Bedrock underlying the Casperkill watershed consists primarily of sedimentary rocks from two formations, the Cambro-Ordovician age (540-443 million year old) Wappinger Group dolomite (calcium-magnesium carbonate) and the Ordovician age (490-443 million year old) Normanskill group (shales and sandstones cemented by calcium carbonate). These rocks are overlain by sediments left behind by an ice sheet that covered this area until about 18,000 years ago (~15,300 years radiocarbon). These sediments consist of unsorted mixtures of large rocks and finer silt and clay known as glacial till, produced as the ice sheet ground over the underlying bedrock, along with lesser quantities of sediments deposited by streams issuing from the melting ice. The latter sediments include stream, delta, and lake sediments and tend to be better sorted and finer grained than the glacial till. The fact that the Casperkill flows through rocks and sediments containing abundant calcium carbonate means that the stream water is well buffered from acid rain inputs, and our measurements place the pH of the stream between 6.5 and 8 on a scale of 1 (acidic) to 14 (alkaline), where 7 is considered neutral.
Soils in the watershed are typically loamy (containing mixtures of sand, silt, and clay), with silt loams developed on glacial lake deposits and gravelly loams on till. Soils are assigned a drainage class value that reflects the rate at which rainwater percolates through them. Class A soils transmit water quickly, leading to soils that are well to excessively well drained. Class B soils are considered moderately well drained, class C poorly drained, and class D very poorly drained. Classes C and D commonly generate runoff during heavy rains as pore spaces in these soils fill with water and the slow infiltration rate inhibits downward movement of water. In the Casperkill watershed, nearly 40% of soils are class C or D, with 50% better drained (~10% of soils have unspecified drainage characteristics). Since poorly drained soils make up nearly half the watershed, drainage management is important for both the watershed as a whole and for individual households.
The stream and its surrounding vegetation host a variety of wildlife including birds, mammals, reptiles, fish and amphibians. Birds that utilize the stream and surrounding buffer include robins, chickadees, titmice, scarlet tanagers, blue jays, downy and hairy woodpeckers, Carolina wrens, nuthatches, juncos, eastern bluebirds, sparrows, pileated woodpeckers, red-tailed hawks, swans, ducks, Canada geese and even great-blue herons. Coyotes, rabbits, deer, mice, foxes, skunks, opossums, muskrats, and raccoons are among a few of the mammals that find refuge in the streamside habitat. Additionally, a variety of fish, painted turtles, box turtles, snapping turtles, green frogs, wood frogs, and spring peepers live within the Casperkill.
Fish species diversity in Sunset Lake was last determined in 1992 prior to a sewage overflow into the Casperkill just upstream of the lake that killed off nearly all of the biota as dissolved oxygen levels in the stream and lake plummeted. At the time of the census, the lake was home to largemouth bass, black crappies, red-breasted sunfish, pumpkinseed sunfish, redfin pickerels, mosquito fish, white suckers, yellow bullheads, and goldfish. After the dissolved oxygen crisis abated, Vassar Buildings and Grounds staff hired Northeastern Aquatics to restock the lake with golden shiners, brown and yellow bullheads, bluegills, pumpkinseeds, largemouth bass, and redfin pickerels, but it is unknown which species currently occupy the stream.
The Casperkill also provides valuable habitat for regionally and globally threatened freshwater mussels. Four species of the Unionidae mussel family reside in the Casperkill including the Pyganodon cataracta, Utterbackia imbecillis, Elliptio complanata, and Strophitus undulates. Casperkill researchers studied four other regional streams for the presence of freshwater mussels and found that the Casperkill is the only stream to have four species of Unionidae; the other streams (Fall Kill, Crum Elbow, Landsmankill and Saw Kill) have only one each.
It is necessary to measure a variety of water quality parameters in order to obtain an accurate picture of stream health. Most of the information reported on the water quality of the Casperkill is the product of the work by students and faculty affiliated with Vassar College’s Environmental Research Institute (ERI). Beginning in the spring of 2006 and lasting 22 months, students and faculty conducted water quality monitoring on a monthly basis, assessing such parameters as the amount of salt in the stream and stream soils; dissolved oxygen, nutrients, and bacteria; stream water pH; the extent and species composition of streamside vegetation; the presence of heavy metals in stream water and soils and the presence and composition of aquatic organisms. Most but not all samples were taken at times of low flow, and between rainfall events. The water quality data presented here represents a small subset of the research on the Casperkill, please see the Casperkill Assessment Document for more extensive data.
The New York State Department of Environmental Conservation (NYSDEC) rates streams according to certain water quality indicators and assigns categories indicating acceptable uses. As of August 2008, the NYSDEC designated the entirety of the Casperkill as a Class C stream, although a 1996 NYSDEC document indicates that the stream had previously been designated a Class D stream. The NYSDEC 2008 classification is based primarily on a 2002 benthic macroinvertebrate sample taken at one downstream site (Camelot Road). The assessment attributes possible pollutants to “nutrient enrichment from nonpoint sources” but acknowledges poor BMI habitat conditions contribute to the degraded status of the stream.
Nitrogen (N) and phosphorus (P) are necessary components of ecosystems. When added to crops in fertilizer, they accelerate growth and yield larger harvests. While essential, an overabundance of these nutrients in an aquatic ecosystem can cause environmental harm.
Increased levels of chloride and conductivity in freshwater streams can negatively impact aquatic ecosystems. Conductivity refers to the ability of water to carry an electric current and is dependent on the amount of dissolved solids (including but not limited to chloride) present in the water. The Casperkill has among the highest chloride concentrations of all streams in Dutchess County. Elevated winter levels of chloride suggests that road salt (sodium chloride) is the principal source of chloride in the Casperkill. Conductivity levels also remained high throughout the summer and fall months. The lack of a seasonal variation in conductivity is likely to represent chloride inputs from road salt released gradually through groundwater and soils. Research findings on the Casperkill for Nitrate-N, Ammonia, Phosphate-P and Chloride are summed in the table below:
Iron oxide (orange ooze) precipitates when groundwater from under the Rt. 44 Plaza discharges to the surface. This precipitate contains high levels of arsenic that frequently surpasses the EPA's extreme biological harm threshold of 33 mg/L. However concentrations in the pipe effluent and in the stream itself are well below detection. For more on arsenic and heavy metals in the stream please see the Casperkill Assessment Document.
Coliform bacteria counts can be used to determine whether fecal contamination is high enough to pose risks to human health. Two frequently used coliform indicators are Escherichia coli (E. coli), a type of fecal coliform and total coliform a combination of both fecal and non-fecal coliforms. Casperkill research reveals that the Capserkill frequently fails NYSDEC Class C fecal coliform standards. During the month of July 2007 bacteria counts in the Casperkill exceeded NYSDEC water quality standards for total coliform (2400 CFUs/100 mL median for 5 sample dates) and E.coli (200 CFUs/100 mL, geometric mean for 5 sample dates). CFUs are Colony Forming Units that can be counted to determine the number of bacteria in a given water sample. In some samples, total coliform levels taken after rainstorms reached as high as 9740 CFUs/100 mL. For more information about coliform bacteria in the Casperkill, see the Research page.
Sources of fecal contamination to the stream include companion animal (e.g. cats and dogs) waste washed into storm drains, wildlife feces and improperly functioning septic systems. Geese and other waterfowl as well as deer are two of the most probable sources of wildlife feces in the Casperkill. Waterfowl are particularly attracted to open bodies of water such as that of Vassar Lake (part of the Fonteynkill, the main tributary to the Casperkill) and Sunset Lake, which is on the grounds of Vassar College. Septic system contamination is another possible contributor to the degradation of the Casperkill. For example, many of the homes along Boardman Road do not have access to the town sewer system, and homeowners have reported foul odors from septic system backwash during high rainfall events.
Benthic macroinvertebrates (BMIs) live in the sediments of streambeds for part of or all of their life cycles. Both the abundance of organisms and the diversity of species found provide insight into the general health of the creek and can be used to calculate a biotic index of water quality. Since BMIs depend on environmental conditions similar to those required by trout and other fish, a study of BMI health shows the potential for the health of fish in the creek. This information is especially important given that the NYSDEC Class C rating for the Casperkill designates the creek as suitable for fishing.
The BMI data for the Casperkill reveals that aquatic ecosystem health varies along the stream, with some areas in poor condition and a few (particularly in the Vassar Farm Ecological Preserve) in good health. The BMI community is apparently most strongly influenced by the amount of vegetation in the buffer surrounding the stream, and is relatively insensitive to the overall watershed condition. Low values of biotic index are associated with stream organisms that are extremely sensitive to pollution, whereas high values reflect animals that can tolerate much more degraded conditions. The BMI data clearly shows that the greater the amount of vegetated cover in a buffer zone surrounding the sampling site, the lower the biotic index value, and by inference, the cleaner the water. The lowest biotic index value (3.5, on the dividing line between “good” and “excellent” conditions) was found on the Vassar College ecological preserve, whereas the highest values (7.6, “very poor”) were found in the Dutchess and 44 Plaza area. Based on the benthic macroinvertebrate study, no part of the Casperkill is in “excellent” health. The data also clearly show that the Town of Poughkeepsie’s Aquatic Resources Protection Law, which mandates a minimum buffer size of 25 feet (7.6 m) along stream corridors, is inadequate for protecting stream health. This 25-foot wide buffer falls within the poor water quality range. For more information on BMIs in the Casperkill, see the Research page.
The United States Geological Survey (USGS) maintains an extensive network of gauging stations on streams and rivers throughout the country. Although the Casperkill no longer has a USGS gauging station, scientists from the Vassar College Environmental Research Institute have installed a stream gauge station for the creek. At the Casperkill stream gauge site, the stream overflows its banks after reaching a discharge of approximately 56 cfs, a flow that was exceeded fifteen times during the period of July 10, 2007 to Oct. 30, 2008. In undisturbed watersheds, streams fill to their banks (called bank full level) only once every 1-2 years, so the fact that the Casperkill so frequently overflows suggests that the channel is not in equilibrium with the amount of water it is trying to convey. Potential causes of disequilibrium include a change in climate toward wetter conditions, an increase in the amount of impervious surface in the watershed that speeds runoff into the stream channel, a localized constriction in the channel that backs up water upstream, or some combination of these factors. The fact that the Casperkill overflows its banks during even relatively small storms suggests that the amount of impervious surfaces in the watershed is the likely cause.
Stream disequilibrium can increase erosion as the stream deepens and widens its channel to accommodate higher flows. Erosion constitutes a problem for some property owners, who have witnessed channel migration that threatens loss of land. It is also a problem for aquatic ecosystems, which suffer when sediments are washed into streams, smothering filter feeders and changing the grain size of materials on the channel bottom. Nooks and crannies between gravel and cobble-sized rocks that are used as shelter by stream-bottom organisms may fill in with eroded sediment and destroy habitat. In addition, some fish species require a particular grain size of sediment to shelter their eggs. As erosion proceeds, their spawning grounds may disappear. Channel bottom cobble embeddedness data suggest that the Casperkill may suffer somewhat from sedimentation issues.
Public access to the Casperkill currently exists in four areas along the creek, the Dutchess and 44 Plaza shopping area, the Vassar College campus, the Vassar College Farm and Ecological Preserve, and the Casperkill Golf Club. None of these locations are protected town or county resources, thus future public access is not ensured. On the other hand, it seems unlikely that the landowners will restrict access. While the stream is accessible from parking lots in the Dutchess and 44 Plaza area, the lack of shade trees and benches and the ubiquity of garbage on the stream banks and in the channel make this site unappealing; most residents don’t even know that the perceived drainage ditch along the edge of the shopping area is actually the stream.
On the Vassar College campus, the stream is paralleled along much of its length north of Sunset Lake by a campus roadway on the western bank and a gravel footpath along the eastern bank. Gravel trails ring the lake and another gravel trail on the floodplain follows the stream southward toward Rt. 376. Families from the local community are often seen around the shores of Sunset Lake, picnicking, fishing, and catching butterflies and tadpoles. Benches and lawns provide seating areas.
At the Vassar College Farm and Ecological Preserve, walking, biking, and running trails follow the stream. An expansive area of mowed fields and woodlands provides educational opportunities for Vassar College students taking courses in Environmental Studies, Earth Science, Biology, and Art, to name a few, and to local elementary school children participating in the Exploring Science program run by the Vassar Department of Education. Bird watching is another favored activity on the Ecological Preserve. Local high school cross-country running teams make use of the trails, and the College provides public access to the site free of charge.
The Casperkill Golf Club is an 18-hole golf course and driving range area designed by Robert Trent Jones Senior. The Casperkill stream features prominently in the Golf Club’s description of the course as an aesthetic amenity, however greens fees and the danger of golfing activities may limit public access to this site.
Double click on the map to zoom in, or click on an icon to get more information about a public access site!
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Indicates a public access site on the Casperkill
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 Wappinger or a tributary to the Wappinger
Indicates a public access site on the Fishkill Creek
Indicates a public access site on the Ten Mile River or a tributary to the Ten Mile River
Indicates a public access site for the Roeliff Jansen Kill
In a recent Casperkill Stakeholder survey, watershed residents identified three primary threats to the Casperkill :
By Dr. A. Scott Warthin, Jr., Prof. of Geology, Vassar College
Once upon a time a little stream began, clear and sweet, in a swamp where the green herons perched in the buttonbushes, and the marsh wrens nested in the long cattails. What this stream may have been called by the Wappinger Indians we do not know, but early Dutch settlers called it the Casperkill. Along its banks the mink and otter hunted and played, while the deer came through the forest to quench their thirst.
The Indians, never of great number, used the stream in small ways; but these ways were in truth so small that they had no visible effect. Some four thousand years of habitation by Indians left the stream and its denizens as little changed as the forests along its banks.
But when the land was granted in patents and sold to settlers the great change began. Forests fell to clear fields, and to furnish lumber and fuel. The Casperkill suffered its first conspicuous indignity in the construction of a mill in its lower reach. Less obvious changes also occurred. Spring rains washed soil from the bare wheat fields, muddying at times the once clear spate. The hot rays of the summer sun warmed the waters that had been sheltered by trees along the banks. And other misfortunes came, at first slowly but at last in a crescendo of disaster. Beneath the headwater swamp lay beds of clay; this was used for the bricks that built much of old Poughkeepsie and the early buildings of Vassar College. When the brick plant closed in 1932 nearly half the swamp had been replaced by a pit, soon full of water. That phase of history remains today only in the name of Brickyard Hill, east of the swamp.
But that hole full of water? What a marvelous place to dump garbage! So a citizen with foresight bought the worthless hole and leased it to the Town of Poughkeepsie for a dump, and the waters that flowed from the swamp down the Casperkill became rich with the organic material of the decaying garbage and charged with iron from the rusting cans. The decay process used up the oxygen normally dissolved in the water; many kinds of life that had swarmed in the stream were drowned in the waters that once nourished them. Some life, however, survived and found that the waters, though fetid, were richer than ever with the decaying organic matter; these things flourished. So the Elodea and waterlilies that once grew in Sunset Lake on Vassar College campus, were replaced by ugly mats of algae. The coliform count of the water grew so high that the Vassar girls had to give up the kayaks in which they once sported. As the sunfish and bass that swam in the lake were replaced by goldfish and carp, so the water loving plants around its edge gave way to Yellow Flags and Sagittaria. And for years, when the Town burned its dump thrice weekly, a north wind brought a snow of burnt paper ashes on the water.
A few atrocities were corrected; a gravel miner was required to settle the mud from his wash water before returning it to the stream. Vassar College ceased to use Sunset Lake as a cooler for condenser water from the power plant. And in time more people protested the Monday-Wednesday-Friday smog from the burning dump, so dumping at that spot ceased. Of course, it was coincidence that the dumping space had by then all been filled up well above water level, and was now valuable land. So we come to the era of industry and the supermarket, surrounded by acres of parking lots, where rainfall must be drained away at once or business suffers. And where can the storm sewers most cheaply discharge? Poor Casperkill! Today, even a modest rain promptly produces a brown turbid fluid discharge, courtesy of Shoprite and the Great Atlantic and Pacific Tea Company. It is not, however, tea, and it is (slowly, we hope) filling Sunset Lake, which is the first settling basin in its path. And nestling in this unlovely mud are other artifacts – item, two auto tires; item, an estimated 300 beer cans and assorted bottles. How the few surviving Painted Turtles can find a place to burrow for the winter it is hard to imagine. Snug indeed, between Schlitz and Rheingold, in mud spiced with fuel oil released into the Lake by mistake. Why is it that nearly all mistakes made with water are detrimental?
The New York State Water Resources Commission, in effect, has declared the situation hopeless above the Sunset Lake dam, giving that portion a “D” classification. On the theory that running water will gradually cleanse itself, and with the septic tank action in Sunset Lake as an assist, the Commission placed a rating of “C” on the Casperkill below Sunset Lake. This would permit fishing, except for trout, which require more dissolved oxygen than the panfish. This is hardly realistic today, but may come to pass when the organic debris in the Town dump has wasted away.
But will the Casperkill ever return to its early state? No, my friend, the marsh wren can never replace the supermarket, so let us have a care for what is left to us before it is too late.
Published in Wings Over Dutchess, newsletter of the Ralph T. Waterman Bird Club, Dec. 1965, Vol. 6, No. 2