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The Gilboa Dam and Schoharie Reservoir
Written by; Howard R. Bartholomew
No discussion of the Gilboa Dam and the Schoharie Reservoir it impounds should begin without first examining the physical characteristics of the Schoharie Creek and its drainage basin above the Gilboa Dam. The Schoharie Creek begins at Acra, Greene County, NY, 29 miles upstream of the Schoharie Reservoir and has a catchment area of 314 square miles. The rate of descent of the Schoharie Creek from Acra (elev. 2,500') to the Reservoir, which begins just north of the bridge at Prattsville (elev. 1,130’), is as follows: 550' drop over the first mile, an average of 36.5 feet per mile for the next 14 miles, 24.5 feet per mile for the next 10 miles, and 14.5 feet per mile for the final 4.5 miles.(1) The over all length of the Schoharie Creek, from Acra to its confluence with the Mohawk River in Montgomery county at Fort Hunter, is 85 miles. In the 19th century, much of the Catskill watershed of the Schoharie was clear cut of its native Hemlock forest to meet the demands of leather tanneries, though most of the region is now covered by second-growth forest.(2)
The Gilboa Dam and Schoharie Reservoir are actually one part of the “Catskill System”. Other key components of the Catskill System related to the Schoharie Reservoir are the Shandaken Tunnel which can supply over 500 million gallons of water a day from the Schoharie Reservoir to the Ashokan Reservoir in Ulster County. The Ashokan Reservoir then sends its waters to the Croton and Kensico reservoirs in Westchester County via the Catskill Aqueduct and from there on to NYC. A remarkable fact of this system is that 95 % of water from the West-of-Hudson reservoirs in the Catskill Mountains flows to NYC only by means gravity.(3)
While the Schoharie Reservoir is the smallest of the six West-of-Hudson Reservoirs, it has the most productive watershed. This is due in part to the presence of 3 high peaks in its drainage basin: Hunter Mt. (elev. 4,040'), Westkill Mt. (elev. 3,880') and Windham High Peak (elev. 3,524').(4) Copious amounts of precipitation fall annually within the watershed due to the close proximity of these mountains to the Hudson River (elev. sea level); Hunter Mt. is but 12 miles from the Hudson. As warm, humid air flows north along the east coast of the US it rises and cools over the high peaks of the Catskills. Air loses its ability to hold moisture at an increasing rate as it cools and hence the Catskill Mts. “cloud raking” ability. Water is the Catskill Mts. most valuable resource, without it New York City would be hard pressed to exist.
History
The Gilboa Dam site is located on the site of the former Village of Gilboa. The Dam bisected the village, extending from east to west across the Schoharie Valley, at right angles to the Schoharie Creek. 430 buildings were burned to a distance of s ix miles upstream of the Dam. The Village was a progressive community for its time, with a hydro-electric plant, movie theater, numerous stores, professional offices and its own newspaper, The Gilboa Monitor; all this was lost when the Dam and Reservoir were built. Even the dead within the Reservoir boundaries were affected, with seven cemeteries having been relocated.(5) This destruction of what has been termed “a perfect rural village” and the construction of a new dam and reservoir was made possible by the passage of three laws by the New York State Legislature in 1904 and 1905. These laws gave the newly created New York City Board of Water Supply (NYCBWS), precursor to the present NYCDEP, the right to condemn suitable properties in upstate NY for the building of drinking water reservoirs under the prevue of eminent domain, the basic concept of which is the greatest good for the greatest number.(6)
The condemnation of property and the literal eradication of a community had a very great human impact, best put into words by the pioneering folk historian Emelyn Gardner in the very rare book Folk Lore of the Schoharie Hills: “For a number of summers the village of Gilboa, a leafy settlement on a shallow, rocky stream, served as a center for my work. But there came a time when its destiny foreshadowed by its Biblical name, which signifies 'many springs,' was fulfilled. And on the former site of the charming little village, with its white houses peeping through the trees and the steeples of its churches rising above them, there was constructed a reservoir that daily sends thousands of gallons of pure water into the mains of New York City, one hundred and fifty miles away. While the project of the dam was in the discussion stage the unhappy villagers clung to the hope that 'they couldn't make a dam work at Gilboa.'. But, when the inferno created by automobile trucks, commissary wagons, dynamite, pneumatic drills, concrete mixers, fire, steam, electricity, barracks, mess halls, stables, hundreds of special police, and thousands of workmen convinced Gilboans that the doom of their beloved village was sealed, they first dug up their dead who were sleeping in the little graveyard in the heart of the village and moved them far back of the water line of the reservoir. Next they began to consider their own future. And it is estimated that more than one third of the population died of heartbreak. The remainder dazedly scattered to the four winds to seek abiding places until death should release them from a cruel world, which, they said, seemed to have no place for them. Thus vanished one little village in the vicinity of which much of the present collection of folklore was gathered. Others like it are fearfully waiting for the time when they, too, will be sacrificed to the modern gods of greed and prosperity, which have already claimed eleven hamlets in the Catskill Mountains.” The actual time of construction of the Gilboa Dam, Shandaken Tunnel and the Schoharie Reservoir was between the years of 1919-1927. Because of the early completion of the Shandaken Tunnel, the Schoharie Creek began supplying water to the Ashokan Reservoir in 1926. A temporary diversion dam was placed just north of the intake chamber of the Shandaken Tunnel and water was shunted into the Tunnel “killing two birds with one stone”; supplying water to the Ashokan Reservoir and allowing remaining work on the Reservoir and Dam to be done more easily by lowering water levels of the Schoharie Creek, permitting the closing of the outlet works under the masonry spillway.(7)
Geological Considerations
The bedrock beneath the Gilboa Dam consists of Middle Devonian (~350mya) aged standstones and shales that were deposited in marginal-marine to non-marine environments. These rocks are world famous in geological circles for preserving the remains of the world’s oldest fossil forest known as the Gilboa Forest. Five separate levels of in-situ trees have been found, the first having been exposed as a result of a flood in 1869. In the process of obtaining facing stones for the construction of the dam, the fossil trees were rediscovered at an elevation of 1120' as well as 960'. In each case, the fossil trees were found rooted in layers of blocky, green mudstone with the lower portions of the trees encased in massively cross-bedded sandstone up to 5’ thick. It is interpreted that the trees were living on a delta plain near the shore of a vast inland sea. During times of sea level rise, the streams on the delta experienced dramatic floods with occasional, catastrophic breaches in the natural levees along the streams.(8) Immediately following the breach in the levee, the sediment-laden water of the stream flowed out onto the delta plain entombing the bases of the trees. Evidence for this hypothesis includes the steep cross-beds of the sandstone encasing the trees and the presence of Devonian-aged river-dwelling animals smashed up against the bases of the trees. Hundreds of fossils stumps from Gilboa have found their way to museums in many parts of the world.
The primary controlling features of site selection for the dam were the relation of a deeply buried inner gorge cut down into bedrock on the western side of the Reservoir by a pre-glacial, or inter-glacial stream; the quality of bedrock on the eastern side of the Reservoir and the structure of Glacial drift deposits above the rock. The bedrock beneath the dam is well described in the 1921 NYCBWS 16th annual report: “Geological Conditions-The general level of the foundation for the dam in the old creek bed is about 6 feet below the original surface of the rock and displayed some of the characteristics that have been noted in certain portions of the Shandaken tunnel, in that the rock seems to be under stress; this was first observed in connection with the use of channelers in the cut-off trench. When the channelers cut had been made and the machine had passed on and later returned it was found that the channeler bit could not be inserted in the old slot and that apparently the rock was off-set. Off-sets in the rock were also noticed at other points when the rock in the cut-off trench was removed; the maximum overhang observed being 1/8 inch. This same peculiar behavior of the rock was noted when tightening up the bottom by barring and wedging as ordinarily in sandstone rocks when a wedge is driven in a seam a flat slab can be moved, but in this rock, which is exceedingly brittle, it breaks with a concave breakage and frequently loose pieces are bound in, something as a marble might be when embedded in clay and the clay had subsequently shrunk. Vertical seams are frequent, extending in all directions, being in general continuous only for short distances, and the blocks between these seams overly and underly adjoining blocks, binding the whole mass together; also, in barring and wedging, small chips sometimes break off with a report, flying to a considerable distance.
“Another interesting condition noted in the foundation is an artesian flow from each of the seven diamond-drill holes which had been drilled in the cut-off trench between Stations 13+50 and 14+40. This flow totaled at least 100 gallons per minute and was intercepted at different depths below the floor of the cut-off trench which is at about Elevation 949, one flow starting practically at that level while in another hole the flow was not encountered until a depth of 3 feet had been reached. It was also observed that when the artesian flow began from a hole the leaks from the side-walls in the vicinity ceased and at the end of the year practically no leakage occurred in the side-walls where formerly it had been considerable.” In the 1923 report of the NYCBWS is another interesting note: “A horizontal mud seam at el. 1038' at a thickness of 1-3 inches encountered near section/monolith 8 which continued at approximately the same level to the present easterly limits of the work”. These two observations made when the Dam was being constructed have a direct bearing on the safety issues facing the Gilboa Dam in the early 21st. century. Remedies for these particular problems have been made with apparent success and the methodology of them will be dealt with later in this article.
The Gilboa Dam
The overall length of the Gilboa Dam is approximately 2000'. The spill way portion of the dam is constructed of cyclopean masonry and is 1324' long with the top of the spillway sitting at an elevation of 1130' above sea level with a maximum height to the bottom of the plunge pool of 182'. The spillway starts on the eastern side of the Schoharie Valley and runs west, where it ends with a tower-type structure housing old and unusable release works. Proceeding west of the spillway is a 676' long earthen embankment dam with a concrete core wall 20’ higher than the spillway (1150'). The spillway structure of the Gilboa Dam is of a classic gravity dam design. The cyclopean structure of the dam was cast in 23 separate “pourings” or “castings” called sections, now known as “monoliths”. In the casting of the monoliths no re-enforcing rods were used to “tie” the sections together. Instead large stones 12” in diameter called plums were mixed in the concrete. This coarse aggregate created a rough surface for the adjacent monolith surfaces to adhere to when they were poured. The form of the “old” pre-glacial Schoharie Valley underneath the dam is a long, narrow gorge. As a result, the masonry portion of the spillway was constructed as an ungated overfall. The cyclopean masonry portion of the Gilboa Dam was faced with graywacke that was quarried locally at two sites.(9) Work was completed on the Gilboa Dam in 1927. Hence, the Gilboa Dam is 82 years old and like much of America's infrastructure, it has suffered at the hands of time. A table of relevant statistics relating to the Gilboa Dam and Schoharie Reservoir can be found below:
Schoharie Reservoir
Length-5.8 mi.; max. width-.7 mi.; avg. w.-.5 mi.; shoreline-16.5 mi.; max. dpt.-150’; avg. dpt.-57’; surface area at el. 1130’-1142 acres; vol.-22 bil.. gal.; vol. above intake chamber, el. 1065’-19.5 bil. gal.; vol. @ 1124.5’ notch level-17.5 bil gal.; drainage above Sch. Rev.-314 sq. mi.
Gilboa Dam
Length-2000’; spillway L-1326’; el.- 1130’; Notch-220’ l x 5.5’ d (cut in winter 2006 to lower water levels on Western side of spillway); earthen dam portion with concrete core wall-674’ l; el.-1150’; outlet works-non functioning at present; “blow off” valves & discharge pipes- (2) 30”, (access to these valves was and is hazardous due to deteriorated condition of outlet chamber stairs and the intake works on the upstream face of the dam is buried under many feet of mud. To further complicate matters, the valves are “frozen” due to years of non-use.)
Shandaken Tunnel
Length: 18.1 miles; Tunnel Dimensions: horse shoe shaped 11' 6” high by 10' 3” wide; Intake Level on Schoharie Reservoir: 1065'; Discharge el at “Portal” on Esopus Creek, Allaben, Ulster Co. NY: 985'; Tunnel discharge volume: 900 CFS (cubic feet per second) maximum at present time or approx. 577 mil. Gal./day;Distance from tunnel Portal to Ashokan Reservoir via Esopus Creek: 11.9 miles.(10)
Weather in the Schoharie Watershed
The Federal Energy Regulatory Commission Project Report #2729, published in 1979, states: “The average annual precipitation for the Schoharie Creek Basin is about 40”.(11) A graph of rainfall amounts from 1970-2005 shows rates climbing from around 36” to 42”.(12) For essentially the same area, annual precipitation for 2008 was measured at Albany as 47.79”.(13) For whatever reason we seem to be entering a wetter period than experienced in the time since the Gilboa Dam was completed at 1927. The extent and duration of this trend is yet unknown. One major effect of the increased precipitation has been more frequent flooding throughout the Catskill region. Flooding has occurred throughout the recorded history of the Catskills. It is a natural event that can neither be controlled, much less prevented, at the present time. Various data exists on flood frequency in the Catskills, including "Trout fishing in the Catskills" and the NYCDEP Final Environmental Assessment Gilboa Dam Reconstruction Publication (2008). The fall/winter edition (1996) of the Schoharie Co. Historical Society's “Review” features an excellent article by the late Chester Zimmer on historic floods in the Schoharie Valley. It is based on Newspaper accounts. Of special interest are the flood of Jan. 31. 1839, Oct. 7 1869, Dec. 15, 1901 and Oct. 15, 1903.(14) The winter floods were a disastrous result of rain combined with snow melt and ice jams. The October floods were probably hurricane induced low pressure events with copious rainfall. The flood of Oct. 16, 1955, ranked #2, did not involve snow melt. This statement is based upon newspaper records of the event and the author’s personal observation from the area at the time of the flood. Of special note is the frequency of flooding since 1980.
The Gilboa Dam, with its 314 sq. mile upstream drainage basin, creates far too small a reservoir basin to capture run off from storm events like the ones previously mentioned and prevent high water downstream; it is bound to fill and spill in major storm events. The question is, how can the Gilboa Dam/Schoharie Reservoir be used to mitigate or reduce the severity of flooding and not eliminate the threat of downstream flooding?
The Crisis of 2005 & the creation of Dam Concerned Citizens, Inc.
In October 25, 2005, NYCDEP disclosed the existence of serious structural deficiencies at the Gilboa Dam. Word of the various dangerous conditions prevailing at Gilboa soon attracted the attention of the press and media on local, state, national and international levels. NYCDEP conducted meetings in communities downstream of the Gilboa Dam to inform the public of the nature of the problems they faced at the dam and answered questions regarding public safety. Prior to the October, 2005 crisis NYCDEP was aware of the weakened condition of the bed rock underlying the spillway of the Gilboa Dam. A study entitled “Interim Spillway Repairs” of the Stability Analysis of the Gilboa Dam was prepared by GZA Geo Environmental, Inc, NYCDEP, executive project Manger Paul Costa being on of the authors. “Observations in July, 2000 indicated further loss of stone since 1998 inspections. Near the west end of the discharge channel an 18 cubic yard section of the spillway concrete dislodged along a horizontal construction lift line and was deposited in the channel. Further erosion of the concrete apron in two areas where the stone masonry steps were largely missing resulted in voids up to about 8 feet deep to top of concrete and stone debris. These voids extended up to 14 feet below the channel paving. In a tile underdrain constructed during the 1950s concrete paving was severed. Expedient interim repairs implemented included construction of access into the spillway channel; removal of loose stone and debris from the spillway face; excavation of 4,400 cy of rubble from the channel; preparation of bedrock subgrade with compressed air and water jets; installation of new underdrain pipes; and placement of 3,400 cubic yards of mass cyclopean concrete and 1600 cubic yards of reinforced concrete paving. About 50 percent of the mass cyclopean concrete is recycled stone plums.” The 3,400 cubic yards of concrete and stone were put into an eroded cavity under the side discharge channel at the base of the Gilboa Dam. The foundation of the side discharge channel was and is supposed to act like a “passive wedge” and help hold the dam in place against the downstream pressure of water in the Schoharie Reservoir. To put this into perspective, 3400 cubic yards of concrete would make a wall three feet high by three feet wide by 1.93 miles long, or a cube of concrete approximately 45 feet on a side!
In order to understand the problems existing at the dam it is necessary to take a look at what was causing the dangerous conditions existing in 2005. 1. A real possibility of a “sliding failure” of the dam, in the vicinity of monoliths 13, 14, and 15, should a flood as great or a greater magnitude of the record flood of January 19, 1996 occur. As previously mentioned, the rock underneath the dam was of varying quality and 80 years of inundation had not improved its quality. A risk of hydrostatic uplift of the separately cast monoliths was possible due to poor cohesion with the rock underlying the masonry portion of the dam. Should such a failure occur, the waters impounded in the Schoharie Reservoir would rush downstream causing a major flood. Since the likelihood of such a dam failure was not probable except during a flood event, this would obviously greatly magnify flood damage downstream of the reservoir. Using the Heck-Raas flood modeling methodology, water depths as great as 30' were predicted within the zones of inundation in parts of Schoharie County and one third of the City of Amsterdam, NY, would be under water.(15) Additionally, the Mohawk River west of Amsterdam would rise as far as nine miles upstream and portions of the Village of Scotia and the City of Schenectady would be flooded as well. 2. Sink holes had been discovered in the 1150' high, 676' long earthen portion of the dam. These sink holes (formed by the rotting and decaying of timbers, tree trunks, etc., that had been buried for 80 years) indicated some “piping” of water through and/or under this portion of the dam. As the organic material rotted, it decreased in volume and caused collapse in places on the upstream side of the earthen portion of the dam.(16) 3. Instability was noted on the slopes west of the Schoharie Creek, just downstream of the earthen portion of the dam.(17) Landslides and sloughing has been occurring near the “plunge pool” of the dam.(18) This is of concern as any serious movement of earth below the dam, on the western side of the reservoir would lower the resistance of the dam to a sliding failure.
In response to the above issues of the safety of the Gilboa Dam and the Schoharie Reservoir it impounds, Dam Concerned Citizens, (Inc.) was formed, unofficially in December 2005, the first official meeting having been held on March 14, 2006, and shortly thereafter incorporated as a not-for-profit corporation under section 402 of the Laws of the State of New York. Article III of our by-laws states: “The purposes for which the Corporation is organized is to improve the safety, protection and welfare of Schoharie Valley residents from the threat of flood by causing speedy and thorough repairs to be made, and flood mitigation capability to be added to the Gilboa Dam; inform people about dam issues and flood hazard response; and provide the public a voice in dam and flood issues”. The corporation recognizes a widespread dam safety problem and seeks to accomplish the following goals not only locally at the Gilboa Dam, but worldwide: (1) use of the highest design, construction, operation, maintenance and inspection standards on dams; (2) independent oversight of the design, construction, operation and maintenance of dams by qualified dam engineers, at no cost to local governments or residents; (3) dam owners' indemnification of downstream residents and local governments for financial costs and losses attributable to dams; and (4) increased media awareness and improved quality of media reporting on dam and flood issues.
In addition to the foregoing corporate purposes and except as otherwise provided herein, the Corporation shall have all the general powers set forth in Section 202 of the Not-for-Profit Corporation Law, together with the power to solicit and receive grants, bequests and contributions for corporate purposes. Special thanks are due to Lester Hendrix of Schoharie, NY, for his website which dealt with issues of dam safety and for his hard work in helping to create DCC, Inc.
Current Issues Being Pursued
Issues currently being pursued by DCC, Inc., as well as the ones already mentioned, include: 1. A continuous, sub-surface release of reservoir water into the Schoharie Creek below the Gilboa Dam at a rate of 50-75 cfs. Such a “conservation release” would help to restore the biosphere below the dam to some semblance of its pre-dam condition and should not impede the ability of the reservoir to fulfill its purpose of providing drinking water for NYC. 2. Continuous maintenance,upkeep and operations of the 4 large siphons placed on the Gilboa Dam in 2006. These siphons are capable of discharging approximately 900 cfs at peak efficiency. This approximates the Shandaken Tunnel’s maximum output. Until the low level outlet works are installed, there exists no viable sub-surface or low level outlet in the Gilboa Dam, the siphons are a useful, temporary tool to lower reservoir levels by discharging water up and over the Gilboa Dam into the Schoharie Creek. During the state of emergency at the Gilboa Dam from October 2005-December, 2006, water was discharged in excess of Ashokan Reservoir needs through the Shandaken Tunnel, simply to keep the Schoharie Reservoir levels low enough to avoid the risk of a sliding failure. This caused high water problems on the Esopus Creek but was deemed an acceptable practice as the risk of dam failure at Gilboa was unacceptable. DCC Inc. does not wish to impose any further burden on the Esopus watershed and therefore supports the continued presence of the siphons at the Gilboa Dam. 3. Continuous monitoring of the 80 post-tensioned anchors on the masonry portion of the Gilboa Dam, via “sentinel anchors” placed adjacent to the Gilboa Dam. These anchoring devices exert downward pressure on the spillway, which is a gravity dam, helping to increase its overall factor of safety. DCC, Inc. would like to see a sentinel anchor installed on the Gilboa Dam spillway so that actual measurements, of tension exerted on the submerged bed rock, could be observed. 4. The creation of a position of “public inspector” for the renovation work to be done on the Gilboa Dam commencing in the fall of 2010. This inspector would report to the public of any deficiencies, difficulties, or problems encountered in the rebuilding of the Gilboa Dam. There will be many agencies and entities represented by inspectors at the dam work site. However, none of them report directly to the public. In light of past difficulties at the Gilboa Dam, the public is entitled to know the unfiltered and unvarnished truth about the Dam as work proceeds. 5. The construction of a additional “Crest Wall” on top of a portion of the existing spillway of the Gilboa Dam. Based upon the success of the 220' long 5.5' deep Notch placed in the Gilboa Dam in 2006, used to lower reservoir levels, void creation for high water events and flood attenuation, DCC, Inc. firmly believes an additional flood attenuating device in the form of a “Crest Wall” should surmount the existing spillway. More details on this “Crest Wall” can be obtained by reading Symbiosis The Crest Wall.
Contact Information
For more information on matters relating to the Gilboa Dam and Schoharie Reservoir, please contact Dam Concerned Citizens, Inc., PO box 310, Middleburgh, NY 12122-0310, (518)827-9558, www.dccinc.org.
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Footnotes
1. Austin, Francis M., “Catskill Rivers”, p. 210.
2. Evers, Alf, “The Catskills”, p. 343.
3. Galusha, Diane, “Liquid Assets”, p. 265.
4. Evers, Alf, “The Catskills”, front piece.
5. Thomas, Alexander R., “Gilboa”, p. 170.
6. Thomas, Alexander R., “Gilboa”, pp. 86-101.
7. Merriman, Thaddes, Board of Water Supply Annual Report, 1923, p. 93. plate 6.
8. Bartholomew, Alexander J., “Stratigraphic Determination of the World’s Oldest Fossil Forest, Gilboa, NY”, 79p.
9. Fluhr and Terenzio, Engineering Geology of NYC Water Supply System, p. 34.
10. Gilboa Historical Society, L.T. Stratigos, ed., “Gilboa, 1848-1998”, p. 71. Galusha, “Liquid Assets”, p. 270.
11. FERC, Prattsville, NY Project, July 1979, pp. 2-17-2-18, vol. I.
12. Titus, Robert, Precipitation Graph.
13. Daily Gazette-Jan. 1, 2007, 2008. & 2009, Annual Weather summaries.
14. Zimmer, Chester, Article, Schoharie County Historical Society Review, fall-winter, 1996.
15. GZA (commissioned by NYCDEP) Dam Break Analysis, Job #15,375.64.
16. Joint venture, (Gannett Flemming/Hazen Sawyer) observations of explorations at Depressions 1 & 2. Environmental Assessment of Gilboa Dam Reconstruction, Fig. F-10.
17. Soil Survey of Schoharie County., pp. 66, 67, 74, 75, 98 & 111, map #72.
18. Environmental Assessment of Gilboa Dam Reconstruction, 1.5.9 pp. 41,42.
Bibliography
Public Records
1. Board of Water Supply, City of New York-Annual Reports 1917-1927, Thaddes Merriman, Chief Engineer.
2. Federal Energy Commission, Prattsville Project #2729 FEIS FERC, July 1979, vol I& II.
3. GZA Environmental Inc., One Edgewater Drive, Norwood, Ma, 02062. “Stability Analysis and Interim Safety Improvements Gilboa Dam Spillway, Schoharie Reservoir, NY, Abstract 2001, Report US Society of Dams, Wm. H. Hover, Anders B. Bjorgard, Chad W. Cox and Paul Costa.
4. Joint Venture, (Hazen-Swayer/Gannett Flemming), “Explorations of Depressions 1&2, Sept. 23, 2005.
5. New York City Dept. of Environmental Protection (NYCDEP), Bureau of Environmental Planning and Analysis, Final Environmental Assessment Gilboa Dam Reconstruction, prepared by Gannett Flemming/Hazen-Sawyer, July, 2005.
6. New York State Geological Survey, “Engineering” Geology of New York City Water Supply System”, Thomas W. Fluhr, p.e. and Vincent G. Terenzio, p.e., Oct. 1984.
7. Schoharie County Historical Society “Review”, fall/winter, 1996, article on historic floods by Chester G. Zimmer.
Newspapers
8. “The Daily Gazette”, Schenectady, NY, Annual Weather Summaries-2006, 2007, 2008.
Magazines and Scientific Publication
9. Geological Society of America, Bulletin, vol. 106, pp. 1440-1458, “Marine Transgressions and Regressions Recorded in Middle Devonian Shore Line Deposit of the Catskill Classic Wedge”. J.S. Bridge & B.J. Willis, Dept. of Environmental Science, Binghamton University, Binghamton, NY, Nov. 1994.
10. “Stratigraphic Determination of the World;s Oldest Fossil Forest, Gilboa, NY”, Master’s Thesis, Dr. Alexander J. Bartholomew, 79p. University of Cincinnati, 2002.
Books
11. Francis, Austin, M., “Catskill Rivers”, Nick Lyons, 1983, NY, NY.
12. Gardner, Emylyn Elizabeth, “Folklore of the Schoharie Hills”, University of Michigan Press, 1637.
13. Galusha, Diane, “Liquid Assets, A History of the New York City’s Water Supply”, Purple Mountain Press, Fleischmanns, NY, 1999.
14. Gilboa Historical Society, “Susqui-Centennial of Gilboa, NY, 1848--1998”, L.T. Stratigos, ed.
15. Titus, Robert, “The Catskills, a Geological History”, Purple Mountain Press, Fleischmanns, NY, 2004.
16. Thomas, Alexander R., “Gilboa, New York City’s Quest for Water and the Destruction of a Small Town”, University Press of America, Lanham, Md., 2005.
17. Van Putt, Ed., “Trout Fishing in the Catskills”, SKY Hours Publishing, NY, NY, 2007.