Home » Newest Reports » Archive Reports » Letter to DEPs Paul Rush Tina Johnstone
Letter to DEPs Paul Rush Tina Johnstone
February 26, 2007
The following is a presentation from DCC to the County Board of Supervisors and a letter sent to DEPs Paul Rush and Tina Johnstone.
Good Morning, I am Cindy Barber, representing Dam Concerned Citizens and the Public of Schoharie, Montgomery and Schenectady counties. The heavy snowfall we received this week raises two questions regarding the potential for serious flooding of the Schoharie Valley in the next 8 weeks. This snow pack coupled with the fact that the Schoharie Creek is ice bound with a foot of ice from its source at Hunter Mountain in Greene County to Fort Hunter, near its confluence with the Mohawk River in Montgomery County creates an ominous scenario for ice jam induced flooding if a rapid snow melt occurs with a prolonged heavy rain.
In the top 10 Historical Crests, the floods of April 4, 1987, April 3, 2005, March 21, 1980 and April 5, 1984; numbers 3-6, were floods caused by rapid snowmelt and heavy rain. Due to the amount of ice we have at present and the possibility of ice jamming, not a factor in the above mentioned major floods, there is additional concern this year.
With these facts in mind, we would like Chairman Van Wormer to please answer the following two questions: 1. Is NYCDEP implementing its reservoir drawdown program to compensate for heavy snow pack in the 314 square mile Schoharie Reservoir Watershed? 2. Are the Flood Alert Sirens promised for January 2007, in place and operational? If not, when will they be installed and operational? 2/26/07
These are the received answers:
DCC was told that our siren installation was not started on time due to Federal Government Homeland Security supersceding our order. We were told that we should be expecting delivery and work to begin at any time, unless the Government needs additional sirens.
UPDATE:4 of the 8 sirens have been delivered.
The original snow pack water measuring system installed by DEP was removed. The "pillows" were found to be leaking antifreeze, thus causing the cells to freeze and proper readings could not be obtained. Tubes are now being used. These tubes are driven down into the snow, then capped off, the snow allowed to melt, and the water measured is then halved to determine how much the resevoir level will be reduced.
From: sherrie bartholomew
Date: February 28, 2007 12:18:28 PM EST
To: Paul Rush
Cc: J.I. Garver, Alex Bartholomew,
Subject: activating the siphons at Gilboa
Paul and Tina,
Good morning. I hope this letter finds you well. I am writing regarding releasing water from the Schoharie Reservoir via the 4 siphons in advance of what is certain to be a major snow melt that will occur sometime in the next 6 weeks.
We have been told that the snow pack contains upwards of 3.5" of water at present. Foul weather is forecast for Friday which will further saturate the snow in the Catskills with water. These "Frozen Assets" will be released sometime soon,
as spring approaches. The ground is frozen to a depth of several feet, as there was little ground cover prior to the big snow fall of 2/14/07. Thus, the scenario exists for a major flood, should the snow pack of 314 sq. mi.
Schoharie Reservoir catchment area melt in concert with a large amount of rain. Such an event occurred Jan. 18&19, 1996.
In that case the ground was not frozen to the extent that it is now. Also, the Schoharie Creek was not ice bound as it is this year.
The very cold weather of late Jan. and all of Feb. 2007 has caused ice to form on the Schoharie Creek both above and below the Gilboa Dam. By releasing water now via the siphons, the water could incise the ice in the Schoharie Creek, causing it to break up with less threat of forming ice jams and causing serious flooding (due to back up of water) rather than what might occur if release of water were postponed. If ice of this magnitude is in the Schoharie Creek at a time of a major spillage at Gilboa, the potential exists for major property damage and possible loss of life. In the January '96 flood, Route 30 was covered in many places by several feel of water. Fortunately, the flood waters receded on Friday night, 1/18, as a cold front and sub-freezing weather abruptly ended run off and by Sat. morning, 1/19/96 Rt. 30 was passable from Schoharie to North Blenheim. Should a similar amount of water, actually anything in excess of 43,000 cfs. occur at Gilboa in the next 6 weeks with the ice still present on the Schoharie Creek, a catastrophe will occur. The ice will be lifted out of the creek channel and float at a high rate of speed (in excess of 7 mph) downstream, hopping banks, blocking route 30 and potentially sweeping away property and people. When the waters recede roads will be choked with ice and debris.
While the prospect for a high crest at Gilboa is diminished by the presence of the 220'X5.5' Notch at the spillway ele. 1130', the spectre of a large volume of ice laden water rushing down stream at a high velocity is frightening. Early, preemptive releases will insure less water down stream later as, some run off is bound to be retained by the Gilboa Dam. Also, by drawing down the Schoharie Reservoir to the effective working limits of the siphons, these very releases works themselves will be protected from ice damage should a sudden rise of the Schoharie Reservoir and run off occur above the Gilboa Dam. One needs to also consider the fact that there is 29 miles of ice upstream of the Gilboa Dam. Prattsville is painfully aware of the destructive potential of this ice! Should that upstream ice come rushing down the Schoharie and flow over the top of the Gilboa Dam, the potential exist for serious damage to, if not destruction of, the 4 siphons. Thus, I ask again, that you give serious consideration to drawing down the Schoharie Reservoir now while there is still time to do so.
I am not unaware of the implications of the release of water through the siphons on residents of the Schoharie and Mohawk Valleys. Increased stream flow, due to water released via the siphons, should cut the ice and float it down stream in a controlled manner as the water in the creek at Gilboa should not exceed 500 cfs. This ice will ultimately either breakup and melt, stay on the banks of the Schoharie Creek or find its way to the Mohawk River. On the other hand, should the ice go out suddenly, with a big snow melt accompanied by rain, it will jam and break up in a series of "pulses" that will have a devastating effect in Schoharie, Montgomery and Schenectady Counties.
I noticed that at 9:30 a.m. 2/28/07, the release from the Shandaken Tunnel was at 195 cfs. We understand that since the "State of Emergency" was lifted at Gilboa Dam with the installation of the last post tensioned anchor, releases via the Shandaken Tunnel have been reduced by court order. Hence, the only viable way to deal preemptively with the problem now at hand, is to start using the siphons now.
I am enclosing the email address and business phone # of Dr. John Garver, Geologist and specialist in Ice Jamming on the Mohawk River. He is Professor of Geology at Union College, Schenectady, NY. Also, included is the phone # of Mr. William Van Hoesen, Director of Emergency Management for Schenectady County.
Thank you,
Howard R. Bartholomew, Dam Concerned Citizens Dr. John Garver William Van Hoesen...