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The Flood That Wasn't
September 11, 1960

Written by; Howard R. Bartholomew

In late August of 1960, a powerful low pressure system formed in the Caribbean region. It soon reached category three hurricane status and was named hurricane “Donna”. It still holds the record for retaining major hurricane status (category 3 or greater on the Saffir-Simson Hurricane Scale) in the Atlantic Basin for the longest period of time. For 9 days Donna had consistently high winds of at least 115 mph and from the time it became a tropical depression, Aug 29th to when it dissipated into an extra tropical storm, Sept 14th, Donna roamed the Atlantic Ocean for 17 days! For this 17 day period, Donna savaged the whole east coast of the US from Florida to Massachusetts. It caused 900 million dollars, (1960 USD) in property damages, 6.5 Billion in 2009 USD and was directly responsible for the deaths of 364 people. Its wrath was also felt in Atlantic Canada; the provinces of New Brunswick, Nova Scotia, Prince Edward Island, and Newfoundland. While crossing the Atlantic, Donna briefly attained category 5 status.

As Donna headed up the east coast of the US at the end of summer in 1960, Labor Day was at hand and schools were soon to reopen. The Catskills with their high mountains, Windham’s high peak el. 3824’ and Hunter Mt. el. 4040’ and their close proximity to the Hudson River were within range of Donna’s cyclonic fury. The intense counter clockwise winds picked up copious amounts of moisture from the Atlantic and pumped it inland. As this moisture laden air reached the Catskills, it rose and cooled as it flowed over the high peaks resulting in torrential, pounding, relentless, tropical, monsoon like rain. The rain fall figures tell part of the story: Prattsville 5.99”, Westkill 6.23”, Grand Gorge 5.99”, Shandaken Tunnel intake on the Schoharie Reservoir 7.5”, Lexington 6.23” and Tannersville 10”. The USGS Gauge at Prattsville was at 3’ in the morning the day of the storm and reached 18.5’ by 8:30 p.m. At its peak flow, 33,000 cfs of water was flowing under the bridge at Prattsville. At the onset of the storm, the Schoharie Reservoir elevation was at 1097’ , 33 ‘ below the spillway and it filled to capacity and spilled over the top in 18.5 hours.

Earlier, it was stated that the Precip. figures told part of the story. As the late and great Paul Harvey was wont to say, “here is the rest of the story”, as taken from the Stamford Mirror Recorder, Sept 14, 1960 and Sept. 21, 1960 ( scanned articles ) editions.

The impact of hurricane Donna was so great that the name Donna was officially retired in 1964 and replaced by Dora. Locally, Donna caused severe damage. The storm in Western Greene County was so bad that the Bridge over the Bataviakill Creek 1 mile east of Prattsville at the intersection of 23 and 23A was washed out. This excerpt from the Stamford Mirror Recorder 9/14 & 21/1960 editions tell of the human and financial impact of the terrible storm. With a storm of such fierce intensity, a very reasonable question would be; “Why didn’t Donna cause a flood such as occurred on October 16 & 17, 1955?”. There are several interrelated factors that converged in Oct. of 1955, to produce the Schoharie Valley’s 2nd most severe flood, that were absent from the hurricane induced flooding upstream of the Gilboa Dam on Sept. 11, 1960. They are as follows: (1) timing-the hit song “What a Difference a Day Makes” could be altered a bit and read “What a Difference a Month Makes” regarding flood potential; trees and other vegetation were still actively growing in early Sept. and their capacity to take up water was active as they had not yet shed leaves or entered into seasonally induced dormancy; the average deciduous tree in the Catskills has over one acre of moisture retaining surface area in its leaves. By Oct. 16th & 17th leaves were falling and their capillary retention of rain on forest foliage was greatly reduced. On a 314 sq. mi. drainage basin that was 78% forest in the 1950’s, this amounted to a lot of water. (2) The Schoharie Reservoir was “full to the brim” and spilling over in Oct. 1955, prior to the remnants of Hurricane Katie dumping its burden of water in the Schoharie Watershed. As previously mentioned, on the morning of Sept. 11, 1960 the Schoharie Reservoir was 33’ below the crest level of the Gilboa Da, el. 1130’ (pool level being 1097’). Eighteen hours later on Sept. 11, 1960, the Reservoir was full and spilling over. Apprehension concerning a repetition of the Flood of 1955 caused both Middleburgh and Schoharie Central School to close on the 12th. I was entering my Senior year in high school and remember this unexpected “day off” and, also, wondering why school was closed when there was no serious flooding in the Schoharie Valley below the dam.

In the real estate business they say that “location is everything”. In predicting the potential of flooding, timing may not be everything, but it is certainly a major component of the risk of floods; ie. (1)what time of year is it? an active growing season or is the ground frozen; (2) what is the duration of a storm? does it pass through quickly as Donna did in our area or does it “stall” and pump moisture in for 2 or 3 days. The rate of speed X time or duration of travel = distance in the transportation industry. The rate of precipitation X time or duration of rainfall or snowmelt or a combination of both = run off in estimating the volume of run off when a flood occurs. It is not quite as neat and “buttoned down” as the computation of distance traveled, but it is a good predictive tool.

What lessons can we take away from having read about the flood that wasn’t in the lower Schoharie drainage basin? Here are a few and perhaps you can think of others! (1) the importance of a “void” or storage capacity behind the Gilboa Dam in a major storm event. The one in 1960 was not created intentionally or a means of flood control, but rather was the result of a summer long drought that caused the Schoharie Reservoir to be lowered. (2) Did you notice there was no mention of stream flow data on the Bataviakill, Manor kill, or Bear kill. All three of which are important tributaries entering into the Schoharie Reservoir catchment. Why? because there were not yet “gauged” or monitored streams. Thus, it was more difficult to predict rises in reservoir levels since run off was not measured on some major sources of water. Gauge stations on the 3 tributaries were constructed after the flood of Jan. 18th & 19th, 1996 and it is with alarm that the public received news of the closing of several USGS gauge station in the Schoharie Watershed on the Bataviakill. These are not “real time” gauges but rather height sticks, but never the less, they are better than nothing in estimating stream flow.

Below is the daily mean stream flow as measured at Prattsville, USGS 01350000 from Oct. 10-20, 1955 compare to daily mean stream flow from Sept.10-20 1960. These tables illustrate the Schoharie Creek response to Hurricane Katie of Oct. ‘55 and Hurricane Donna of Aug./Sept. 1960.

Below is the daily mean stream flow as measured at Burtonsville, NY USGS 01351500 from Oct. 10-20, 1055 compared to stream flow from Sept. 10-20, 1960. These tables illustrate response of the Schoharie Creek to Hurricane Katie of Oct. ‘55 and Hurricane Donna of Aug./Sept. ‘60.

As there were no stream gauges in operation at North Blenheim or Breakabeen in either 1955 or 1960 much valuable data regarding stream flow is unavailable to us. However, these conclusions can be reached from information provided by the previous four tables. (1) The Schoharie Reservoir was full at the onset of the flood of Oct. 1955. This is borne out by the fact that stream flow more than doubles at Burtonsville as compared to Prattsville in the days preceding the flood. (2) We know that the Schoharie Reservoir was at el. 1097’ or 33’ below the spillway at the onset of the flood in Sept. 1960. Please note that there was more water measured at Prattsville than Burtonsville in the days leading up to the “flood that wasn’t”. (3) Note that the amount of water at Burtonsville the day before the peak of the flood on Monday, Sept. 12, 1960; 5,640 cfs. Compare that to the day before the peak of the flood on Saturday, Oct. 15, 1955; 6,320 cfs. Using a “perpetual calendar” to tell us the day of the week for the dates illustrated, we know that the “creek peaked” on Sunday, Oct. 16, 1955 at Prattsville and several hours later at Burtonsville. Interestingly, the creek took a day longer to crest in the “flood that wasn’t” in Sept. 1960; the peak at Prattsville on Monday, Sept. 12, 12,900 cfs daily mean and at Burtonsville on Tuesday, Sept 13, 17,000 cfs. As mentioned earlier, words to a popular old song...”What A difference a day makes”...the 24 little hours in the song actually were only 18 hours according to newspaper articles of Sept. 14th & 21st, 1960. In the 18 hours it took to fill the Schoharie Reservoir to over flowing from el. 1097’ to el. 1130’ crest of spillway, the storm passed in and out of our region. One can only speculate as to what might have occurred downstream of the Gilboa Dam had the Schoharie Reservoir been full in Sept. 1960. As the scanned articles from the Stamford Mirror Recorder indicate
( a contemporary account of the flood ), there was terrible property damage upstream of the Gilboa Dam and a drowning.

We can draw the following conclusions from the flood of Sept. 12, 1960. (1) a major storm can fill the Schoharie Reservoir when it is more than half empty. Reservoir capacity at el. 1097’ is approx. 8,800,000,000 gallons of water and at 1130’, the old full pool (pre-notch) level 19,580,000,000 gallons. (2) Any preemptive draw down of the Schoharie Reservoir to create a void to accommodate run-off from whatever source at any time of the year, serves to attenuate the time it takes to fill the reservoir before it spills. In the case of the “flood that wasn’t” or perhaps “almost was”, the void was created by the transfer of water from the Schoharie Reservoir to the Ashokan Reservoir during a long, dry summer via the Shandaken Tunnel. When the new low level outlet is in place under the Gilboa Dam five years from now, this mechanism could and should be used, if a hurricane induced flood is likely to occur, to preemptively mitigate flood damage down stream of the Gilboa Dam. This process in concert with the DCC proposed Crest Wall, see references to this in other articles on our web site, could greatly reduce downstream flood damage by attenuating reservoir spillage and lowering water levels downstream of the Gilboa Dam, turning future major storm events into “floods that weren’t”!

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