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Mohawk Watershed Symposium
2010
Abstracts and Program
Olin Center, Union College
Schenectady NY
19 March 2010
© Geology Department, Union College, Schenectady N.Y. 12308-3107. All rights reserved.
No part of the document can be copied and/or redistributed, electronically or otherwise, without written
permission from the Geology Department, Union College, Schenectady NY, 12308-2311, USA.
iii
Preface
We are making progress. The Mohawk River Basin Program Action Agenda has
emerged from the DEC and primary stakeholders, and in that initial blueprint for action
has emerged a mission that is at the heart of much of what we are all concerned with:
The mission of the Mohawk River Basin Program is to act as coordinator of basin-wide
activities related to conserving, preserving, and restoring the environmental quality of
the Mohawk River and its watershed, while managing the resource for a sustainable
future. Vital to the success of the program is the involvement of stakeholders and
partnerships with established programs and organizations throughout the basin.
An important emerging consensus is that integrated watershed management is the key to
our future success. Ecosystem Based Management is a clear and explicit guiding
principal that now appears to be integrated and fully woven into the fabric of our future
direction. With the NYS Department of State’s decision to support the Mohawk River
Watershed Coalition of Conservation Districts’ proposal to implement a Comprehensive
Watershed Management Plan for the Mohawk Basin.
We can now look to the Mohawk Watershed Coalition of Conservation Districts, recently
funded by NYS Department of State, to implement the different facets of the
Comprehensive Watershed Management Plan for the Mohawk Basin.
This is the second annual symposium on the Mohawk Watershed and we are proud to
present a full and interesting program with excellent papers and ideas that cover a wide
range of topics in the Watershed.
We hope that the continued spirit of information exchange and interaction will foster a
new and better understanding of the intersection between Science, Engineering, and
Policy in the watershed.
John I. Garver Jaclyn Cockburn
On the cover: Bare earth LiDAR image of the lower reaches of the Schoharie Creek in Montgomery
County (see Marsellos et al., 28). The image shows the current river channel as well as a series of
abandoned meander scrolls left from progressive and continuous downward incision since deglaciation. A
small part of I-90 can be seen on the image on the top left. LiDAR provides us with an unprecedented view
of topography and landforms. On this image the small elevation differences of roads and ditches can be
seen. This is a “bare-earth” model, which means that vegetation and many anthropogenic features (such as
houses) have been removed.
Mohawk Watershed Symposium - 2010
19 March 2010, Olin Center, Union College, Schenectady NY
- Final Program -
Friday 19 March 2010
Oral session (Olin Auditorium) - Registration and Badges required
8:30 8:50
Registration, Coffee. Olin Foyer
8:50 9:00
Introductory remarks
John I. Garver, Geology Department, Union College
9:00 9:25
Mohawk River: Erie Canal; Its one in the same (Invited)
Howard Goebel, Canal Hydrologist, New York State Canal Corporation
9:25 9:42
EST: Linking watershed protection with youth development through community based volunteer stream
monitoring programs in the Mohawk Watershed.
John McKeeby, Executive Director, Schoharie River Center
9:42 9:59
Comparative analysis of volunteer and professionally collected monitoring data
Kelly Nolan, Director of Environmental Services, Watershed Assessment Associates
9:59 10:16
Ice jam history, ice jam mitigation training and ice jam mitigation efforts in the Mohawk River Basin
John Quinlan, Lead Forecaster, National Weather Service, Albany, NY
10:16 10:33
Learning through experiments and measurements: the Mohawk Watershed as an outdoor classroom
Jaclyn Cockburn, Geology Department, Union College
10:33 11:03
COFFEE and POSTERS (see below for listing)
11:03 11:28
A new look at the formation of Cohoes Falls (Invited)
Gary Wall, Hydrologist, United States Geological Survey
11:28 11:45
Weather and climate of the Mohawk River Watershed
Steve DiRienzo, Senior Service Hydrologist, NOAA - National Weather Service
11:45 12:02
Landslides in Schenectady County
John Garver, Geology Department, Unoion College
12:02 12:19
Use of high-resolution LiDAR images to identify slopes with questionable stability along the Mohawk River
banks
Ashraf Ghaly, Department of Engineering, Union College
12:19 12:36
Historic flooding at selected USGS streamgages in the Mohawk River Basin.
Thomas Suro, Hydrologist and Engineer, United States Geological Survey
12:36 13:46
- LUNCH -
13:46 14:11
FEMA flood maps, flood risk and public perception (Invited)
William Nechamen, DEC NYS
14:11 14:28
Peak shaving: An approach to mitigating flooding in the Schoharie and Mohawk Valleys
Bob Price, Dam Concerned Citizens
14:28 14:45
US Army Corps of Engineers approach to watershed planning
Jason Shea, Civil Engineer/Watershed Planner, US Army Corps of Engineers
14:45 15:02
The Hudson and the Mohawk: working together
Frances Dunwell, Hudson River Estuary Coordinator, New York State Department of Environmental
Conservation
15:02 15:32
COFFEE and POSTERS (see below for listing)
iv
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
15:32 15:57
Mohawk River Watershed Coalition of Conservation Districts and its comprehensive Watershed
Management Plan (Invited)
Amanda Schaller, Resource Conservation Specialist, Montgomery County Soil & Water Conservation District
15:57 16:14
The case for conservation releases from the Gilboa Dam: impact on riparian habitat and water availability
on the Schoharie Creek
Howard Bartholomew, Dam Concerned Citizens
16:14 16:31 Protecting water quality through a watershed approach
Kevin Millington, Coastal Resources Specialist, New York State Department of State
16:31 16:48
An overview of water rights in New York State
Frank Montecalvo, Consultant, West Canada River Keepers
16:48 16:58 Discussion and Conclusions
Jaclyn Cockburn, Geology Department, Union College
Symposium Reception (Old Chapel) 5:30 PM to 6:30 PM, Dinner and Keynote to follow
Poster session (all day)
F1
The Gilboa Dam and the role of Dam Concerned Citizens as a citizens' advocacy group
Sherrie Bartholomew, Dam Concerned Citizens
F2 Methods and techniques of stabilization of soil slopes
Ashraf Ghaly, Department of Engineering, Union College
F3
West Canada Creek Watershed Map
Kathy Kellogg, West Canada Creek Riverkeepers
F4 Colloidal concentration estimation using ADCP echo intensity
Bill Kirkey, Research Assistant, Clarkson University
F5
Thermal characteristics of Schohaire Creek and its consequences for Brown Trout (Salmo trutta)
Ashley Kovack, Environmental Science Program, Union College
F6
A late Holocene record of Mohawk River flooding preserved in a sediment core from Collins Pond in Scotia,
NY
Mark Krisanda, Environmental Science Program, Union College
F7 Aqueous photolysis of organic ultraviolet filter chemicals
Laura MacManus-Spencer, Chemistry Department, Union College
F8
Mapping and volumetric calculation of the January 2010 Ice Jam flood, lower Mohawk River, using LiDAR
and GIS
Antonios Marsellos, Research Associate, Geology Department, Union College
F9
Determination of historical channel changes and meander cut-off points using LiDAR and GIS in Schoharie
Creek, NY
Antonios Marsellos, Research Associate, Geology Department, Union College
F10
A tree-ring record of slope stability along Sandsea Kill, Schenectady County, NY
Nicole Reeger, Environmental Science Program, Union College
F11
The effects of storm duration and intensity on the urban watershed
William Schoendorf, Geology Department, Union College
F12
Schenectady County Environmental Advisory Council (SCEAC) and its activities related to water and
climate
Mary Werner, Chairperson, SCEAC
v
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
Symposium Reception (Old Chapel) 5:30 PM to 6:30 PM, Dinner and
Keynote to follow
Keynote Address:
Gail Shaffer - Watershed Wisdom: The Politics of Change
Ms Shaffer will share her reflections on drawing upon her experience in the public policy arena
and in the non-profit sphere, to identify strategies of value to citizens in effecting change in our
challenging political climate
Gail Shaffer is a native of the northern Catskill Mountains, having grown up on a farm in
Blenheim, in Schoharie County. Her public service career spanned two decades. She served
twelve years as New York Secretary of State. Prior to that she served in the New York State
Assembly, representing Schoharie County and parts of Albany, Schenectady, Montgomery and
Delaware Counties. She began her public career as a town supervisor and county legislature.
She graduated summa cum laude from Elmira College, majoring in political science. A member
of Phi Beta Kappa and valedictorian of the class of 1970, she also studied political science at
the University of Paris during her junior year. Locally, she attended a one-room schoolhouse in
Blenheim and graduated from Gilboa Conesville Central School.
Currently a writer, Shaffer is among the founding board members of Dam Concerned Citizens,
Inc., a not-for-profit watchdog organization that advocates for dam safety at Gilboa Dam
(Schoharie Reservoir) as well as statewide, nationally and globally.
For details and further background material refer to the Shaffer and Currie abstract (p 61)
Citizen Participation: Grassroots organizing to impact policy - Dam Concerned Citizens as a
case study
vi
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
vii
TABLE OF CONTENTS
Preface -------------------------------------------------------------------------------------------------------- iii
Schedule------------------------------------------------------------------------------------------------------- iv
Keynote Address -------------------------------------------------------------------------------------------- vi
Table of Contents -------------------------------------------------------------------------------------------vii
List of Abstracts (alphabetical)
The case for conservation releases from the Gilboa Dam: impact on riparian habitat and
water availability on the Schoharie Creek
Howard R. Bartholomew ---------------------------------------------------------------------------------- 1
Gilboa Dam/Schoharie Reservoir: Concerns, Issues and Proposals
Sherrie Bartholomew, President-------------------------------------------------------------------------- 6
Learning Through Experiments and Measurements: The Mohawk Watershed as an
Outdoor Classroom
Jaclyn Cockburn and John Garver----------------------------------------------------------------------- 7
Weather and Climate of the Mohawk Watershed
Stephen DiRienzo ------------------------------------------------------------------------------------------- 8
The Hudson and the Mohawk: Working Together
Fran Dunwell ----------------------------------------------------------------------------------------------- 9
Historical Landslides and precipitation trends in Schenectady County, Mohawk River
watershed, NY
John I. Garver, Amanda L. Bucci, Benjamin Carlson, Nicole Reeger, Jaclyn Cockburn ------- 10
Use of High-Resolution LiDAR Images to Identify Slopes with Questionable Stability Along
the Mohawk River Banks
Ashraf Ghaly -----------------------------------------------------------------------------------------------14
Methods and Techniques of Stabilization of Soil Slopes
Ashraf Ghaly. ----------------------------------------------------------------------------------------------15
Colloidal Concentration Estimation Using ADCP Echo Intensity
William Kirkey, Chris Fuller, James S. Bonner, Temitope Ojo, Mohammad Shahidul Islam --16
Thermal Characteristics of the Schoharie Creek and its Role in the Reintroduction of
Brown Trout (Salmo trutta)
V. Ashley Kovack, Jaclyn Cockburn and John Garver -----------------------------------------------18
A Late Holocene Record of Mohawk River Flooding Preserved in a Sediment Core From
Collin’s Pond in Scotia, New York
Mark Krisanda, Jaclyn Cockburn, Donald Rodbell -------------------------------------------------- 19
Mohawk River: Erie Canal; Its One in the Same
Carmella R. Mantello and Howard M. Goebel --------------------------------------------------------21
Mapping and volumetric calculation of the January 2010 Ice Jam flood, lower Mohawk
River, using LiDAR and GIS
Marsellos, A.E. , Garver, J.I., Cockburn, J.M.H. ----------------------------------------------------- 23
Determination of historical channel changes and meander cut-off points using LiDAR and
GIS in Schoharie Creek, NY
Marsellos, A.E., Garver, J.I., Cockburn, J.M.H., Tsakiri, K.G. ------------------------------------- 28
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
viii
The Environmental Study Team Program: Engaging Youth and their Communities in
Water Quality Monitoring of their local Freshwater Streams, Lakes and Rivers
John McKeeby, Caitlin McKinley and Zachary McKeeby, ------------------------------------------34
Protecting Water Quality Through a Watershed Approach
Kevin Millington -------------------------------------------------------------------------------------------36
An Overview of Water Rights in New York State
Frank Montecalvo ----------------------------------------------------------------------------------------40
FEMA Flood Maps, Flood Risk and Public Perception
William Nechamen ---------------------------------------------------------------------------------------- 44
Comparative analysis of student, volunteer and professionally collected monitoring data ----
J. K. Nolan, K.M. Stainbrook and C.M. Murphy ------------------------------------------------------ 48
Peak Shaving: An Approach to Mitigating Flooding in the Schoharie and Mohawk Valleys -
Robert Price ------------------------------------------------------------------------------------------------ 52
Ice Jam History, Ice Jam Mitigation Training and Ice Mitigation Efforts in the Mohawk
River Basin
John S. Quinlan --------------------------------------------------------------------------------------------55
A Tree-ring Record of Slope Stability in Sandsea Kill, Schenectady County, NY
Nicole Reeger, Jaclyn Cockburn and John Garver ---------------------------------------------------56
Mohawk River Watershed Coalition of Conservation Districts and Its Comprehensive
Watershed Management Plan for the Mohawk Basin
Amanda Schaller ------------------------------------------------------------------------------------------ 59
The Effects of Storm Duration and Intensity on a Small Urban Watershed
William Schoendorf and Jaclyn Cockburn -------------------------------------------------------------60
Citizen Participation: Grassroots Organizing to Impact Policy
Gail Shaffer and Eleanor Currie ------------------------------------------------------------------------ 61
US Army Corps of Engineers – Watershed Planning
Jason Shea--------------------------------------------------------------------------------------------------67
Comparison of Selected Historic Floods and the June 2006 flood in the Mohawk River
Basin
Thomas P. Suro --------------------------------------------------------------------------------------------68
Aqueous Photolysis of Organic Ultraviolet Filter Chemicals
Monica L. Tse, Jacob Klein, Alison Kracunas, and Laura A. MacManus-Spencer --------------69
A New Look at the Formation of Cohoes Falls
Gary%R.%Wall**************************************************************************************************** 71!
Schenectady*County*Environmental*Advisory*Council!
Mary%Werner%and%Laura%MacManus*Spencer ********************************************************** 75!
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
1
THE CASE FOR CONSERVATION RELEASES FROM THE GILBOA DAM: IMPACT ON
RIPARIAN HABITAT AND WATER AVAILABILITY ON THE SCHOHARIE CREEK
Howard R. Bartholomew
Dam Concerned Citizens, Inc.
PO Box 310
Middleburgh, NY 12122
Thirty-five miles north of its origin at Acra,
Greene Co., NY at an elevation of 2,500’ the
Schoharie Creek ceases, for some considerable
distance, being a perennial stream. Perennial, or
“year round” steams occur where ground water
and surface water systems are naturally and
hydraulically connected. As a result of the 2000’
long, 182’ high Gilboa Dam, the Schoharie
Creek below the dam is transformed into an
intermittent stream. Even in times of drought,
perennial streams keep flowing at a reduced rate.
This is because ground water continues to supply
water to these creeks, rivers, etc. in spite of a
lack of surface water or run-off. Unlike
perennial streams, intermittent streams stop
running during dry weather. Intermittent streams
are normally found in arid regions such as the
American South West. They are sometimes
referred to as dry gulches (1). Some ravines in
the Catskills, which were once conduits for melt
water from the glaciers at the end of the
Pleistocene, are seasonal or intermittent in their
flow. One does not normally expect to see a
stream in a wet region like the Catskills become
intermittent. So effective is the Gilboa Dam, its
grout curtain and cutoff trench in halting down
stream flow of the Schoharie Creek, below the
dam that the creek literally “dries up” for a
distance of .8 miles until the creek is revived by
a minimal discharge from the Platter Kill USGS
#01350120. As this tiny stream has a catchment
of only 10.9 sq. miles, its contribution to the
Schoharie Creek is negligible. A table showing
Platter Kill flow for a 33-year period can be
found www.dccinc.org. The annual
phenomenon of the Schoharie Creek going dry
below the Gilboa Dam generally occurs during
the summer months of June-September. USGS
surface water annual statistics for site
#01350000, Prattsville, NY and site #01350101.
Gilboa, NY can be found at the dcc web site and
the figures speak for themselves. It can best be
summed up by the USGS itself in describing the
situation at Gilboa as “entire flow, run off from
the 315 sq. mile, except for periods of spill,
diverted from Schoharie Reservoir through
Shandaken Tunnel into Esopus Creek upstream
from Ashokan Reservoir for water supply of City
of New York”. An equally dramatic example of
the impact of the diversion of Schoharie water to
Ashokan Reservoir is in the chart “Burtonsville
vs. Prattsville”. Burtonsville is 41 miles, by
creek, North of Prattsville. Burtonsville, USGS
# 01351500 has a catchment area of 649 sq.
miles below the Gilboa Dam, as compared to the
237 sq. mile drainage basin at Prattsville. It is
were not for the substantial ground water
resources of the Schoharie Valley, the Schoharie
Creek at Middleburgh would be nearly as low as
it is below the Gilboa Dam during the dry
summer months (2). Tributary flow is not
measured below the Mine Kill, USGS
#01350140 which enters the Blenheim-Gilboa
Power Project Reservoir and USGS maintains
three more gauge stations below the PASNY
Pumped Storage Reservoir, Blenheim, NY,
USGS #01350180, Breakabeen, NY, USGS
#01350355, and Burtonsville, NY. Several
stream flow data sheets can be found at
www.dccinc.org showing there to be more water
at Prattsville than at Burtonsville! This is not an
anomaly; it happens every year.
We will now briefly turn our attention to the
tributaries below the Gilboa Dam that enter the
Schoharie Creek. As the Schoharie Creek
channel is of pre-glacial or perhaps inter-glacial
origin, it has many “hanging valleys”, where
smaller alpine glaciers met the larger ice sheet
that advanced and retreated only to re-advance
several times during the Pleistocene Epoch (3).
These hanging valleys are characterized with
having one or more water falls. All these
tributaries of the Schoharie Creek in Schoharie
County contain Char, Brook Trout (Salvalinus
fontinalis), Brown Trout (Salmo trutta), and
Rainbow Trout (Salmo gardneri). The latter two
species are introductions in the Schoharie. All
three species move seasonally between the main
stem river, or “Big Creek” as it is referred to
locally, to the mouths of the “tribs” seeking
thermal refuge in the warmer months. Deep,
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
2
scoured “spring holes” abound in the Schoharie,
proper, and are fed by ground water. Two major
tributaries of the Schoharie flow over and
originate in limestone. They are Foxes Creek,
which enters north of the village of Schoharie
from the east, and the Cobleskill Creek, which
enters the main river from the west, and has a
little known water falls formed over thick
sandstone beds near the top of the Schenectady
Formation. Near by is the outfall of spring water
from Jack Patrick’s Cave system. Foxes Creek
has numerous springs and cave water sources.
An excerpt from Jeptha Simms, “The History of
Schoharie County and Border Wars”, published
in 1846 gives an account of the fish present in
the region when it was first settled by Europeans
in the early 18th century. On pages 86-87
Simms states, “Fish are said to have been very
plentiful formerly in most of the streams in
Schoharie County. For many years after the
Revolution, trout were numerous in Foxes Creek,
where now there are few, if any at all. From a
combination of causes, fish are now becoming
scarce throughout the county. In many small
streams, they have been nearly or quite
exterminated by throwing in lime. This cruel
system of taking the larger fish destroys with
more certainty all the smaller fish. Such a mode
of fishing cannot be too severely censured. The
accumulation of dams on the larger streams
proves unfavorable to their multiplication. Fine
pike are now occasionally caught in the
Schoharie, as are also suckers and eels. Some
eighty years ago, a mess of fish could have been
taken, in any millstream in the county, in a few
minutes.” Conditions have improved
considerably since this was written more than
150 years ago.
Another reference to the presence of Brook Trout
in the main stream of the Schoharie can be found
in “The Ultimate Fishing Book”, edited by Lee
Eisenberg and DeCourtney Taylor, Houghton
Mifflin, Co., Boston 1981, p. 56. In a chapter
entitled “Opening Days”, by the late Ernest
Schwiebert we read, “The Schoharie is still a
native brook-trout fishery in its headwaters on
the timbered summits of Indianhead. Its
gathering currents riffle over ledges there,
through vast thickets of rhododendron and the
overgrown walls of abandoned colonial farms
and it tumbles through huge boulders in other
places. The swift runs and pools above Hunter
are classic Catskill water, and in the valley at
Lexington, it becomes a series of sweeping
riffles and smooth flats. There are deep ledge
rock pools downstream, and before the Gilboa
Reservoir (sic) warmed its lower mileages, the
old-timers told us, there had been excellent trout
fishing as far downstream as the covered bridge
at Blenheim”. Two Brook Trout, caught
simultaneously on a “3 fly” cast on May 28,
2008, bears out this statement by Schwiebert.
These fish were caught 1 mile downstream of the
Covered Bridge at North Blenheim at the mouth
of a cold-water spring, in a 14’ deep, scoured
hole in the main stem of the Schoharie. It was
not a “fluke” or a one-time occurrence. All three
species previously mentioned are found below
the Gilboa Dam in spring holes. Pictures of the
aforementioned fish, a map showing the
tributaries of the Schoharie Creek within
Schoharie County, and a map of karst areas for a
portion of the Schoharie Valley can be found at
www.dccinc.org.
The impact of the Gilboa Dam on the fishery of
the Schoharie Creek has been great over the last
82 years, but it has not been devastating.
Walleyes or Pike Perch (Sander vitreus), referred
to by Simms a “pike”, can be found in the big
pools or eddies of the Schoharie. However, the
supply of invertebrates such as fly larvae,
hellgrammites and crayfish, a considerable food
source of Walleye, is negatively impacted by low
surface flow through riffle areas that connect the
big pools of the Schoharie Creek below Gilboa.
The elevation of the Schoharie at the base of the
Gilboa Dam is 939.56’; it is 507.98’ at
Burtonsville. As there are about 40 miles of
stream between these two gauge stations, the
average rate of fall is about 10.8’ per mile.
There are three greatly eroded ledge rock falls on
the Schoharie between Gilboa and Burtonsville:
one above the Covered Bridge, North Blenheim;
a second at Frisbieville between Middleburgh
and Schoharie; and one a short distance upstream
from the gauge at Burtonsville. There is a
smaller ledge of Onondaga Limestone just north
of Middleburgh. As none of these falls are very
high, the rate of drop per mile is relatively
uniform. It is in the area of drop between pools
that the riffles occur. It is these very riffle areas
that suffer most when the Gilboa Dam stops
spilling, as surface water diminishes so greatly in
volume. The annual rainfall for Schoharie Co. is
38.1”, according to the Progressive Farmer
website of 2008, and the average rainfall for the
Schoharie Watershed above the Gilboa Dam is
41”
(www.gcswcd.com/stream/schoharie.eastkill/sch
ohariecreeksmp), a difference of three inches.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
3
With the Gilboa dam acting as a diversion for the
upper reaches of the Schoharie Creek, the
downstream sections of the river are in essence
deprived of the at least three inches of rain per
year. This difference, above and below the
Gilboa Dam, is very detrimental to riffle flow
between pools on the lower reaches of the
Schoharie Creek. A fair question is: Where
could the water “come from” to create a base
level flow of 50-75 cfs at Gilboa, in times of
non-spillage of the dam? The rainfall chart
found at www.dccinc.org shows annual average
precipitation, actual precipitation and a trend line
(supported by local evidence) for the Schoharie
Creek Region. Also, included are annual
weather summaries for the years 2006-2008.
More rainfall is falling in the watershed in 2009
than there was at the time the Gilboa Dam was
built. Accompanying the over 14% increase in
rainfall in the watershed, is the fact that
NYCDEP, operators of the Gilboa Dam and
Schoharie Reservoir, are limited to allowing no
more than a combined flow of 300 million
gallons per day (mgd) from the Esopus Creek (as
measured at Allaben, NY, site #01362200) and
the outfall of the Shandaken Tunnel during the
months of June-October. This seriously impacts
the output of the Shandakan Tunnel in the
summer months when water is so desperately
needed in the Schoharie Creek north of the
Gilboa Dam. Using information provided by
USGS on monthly water statistics for the Esopus
Creek at Allaben, we find that the average
discharge for the Esopus Creek upstream of the
Shandaken Tunnel for the months of June-
September for 1963-2007 was as follows: June-
118 cfs, July-59 cfs, Aug.-39 cfs, and Sept.-60
cfs. Converting the cfs values to millions of
gallons per day, we get the following: June-76.3
mgd, July-38.1 mgd, August-25.2 mgd, and
Sept.-38.8 mgd. Subtracting these figures from
the 300 mgd limit imposed by the “SPDES”
Permit, we arrive at the following average limits
for discharge from the Shandaken Tunnel: June-
223.7 mgd, July-261.9 mgd, Aug-274.8 mgd,
Sept.-261.2 mgd. Converting these mgd
amounts to cfs we arrive at the following for
cubic feet per second output for the Shandaken
Tunnel: June-374.74 cfs, July-405.13 cfs, Aug.-
425.13 cfs, and Sept.-404.13 cfs. As the
carrying capacity of the Shandaken Tunnel is
over 900 cfs at its present state (4), we see that
large quantities of water are left in the Schoharie
Reservoir during times of SPDES compliance by
NYCDEP. The installation of an Obermeyer
Gate system in the 220’x5.5’ deep notch in the
spillway portion of the Gilboa Dam will allow a
full pool level of 1130’ to be achieved as it was
during the years from 1972-2005, prior to the
emergency declaration at Gilboa. Obviously
some of the “extra water” could and should be
used for Conservation Releases from the
Schoharie Reservoir. This is factually
demonstrated from the following figures based
on actual monthly discharges and their mean
monthly quantities over a given number of years.
Some of the measurements are based on records
collected for over century, such as the records
kept on Schoharie flow at Prattsville. Others are
of a shorter duration, such as Toad Hollow. (All
relevant tables are found at www.dccinc.org)
Water input Schoharie Reservoir from USGS Monitored Sources
based on mean of monthly discharges (cfs) for given years
June July Aug. Sept. June-Sept. avg. of total input
Prattsville (1902-2008) 317.00 159.00 126.00 197.00
Toad Hollow (1998-2008) 2.10 0.46 0.48 1.30
Bear Kill (1998-2008) 47.00 15.00 14.00 27.00
Manor Kill (1986-2008) 42.00 17.00 12.00 19.00 _______________________
Total input 408.00 191.46 152.48 244.30 249.06 cfs
Water diverted from Schoharie Reservoir (cfs) since SPDES Compliance (2005-2008) by NYCDEP
June July Aug. Sept. June-Sept. avg.
Shand. Tunnel 209.6 227.3 189.8 199.6 206.57 cfs
Based on the latest discharge figures since the
SPDES constraints have been in effect, we see
that the month of June had a 198.40 cfs “surplus”
over “output” from the Schoharie Reservoir; the
month of July had an output of 35.70 greater
than combined reservoir input; Aug. was a
negative figure also at 37.74 cfs, Sept. was
positive 44.7 cfs over output. Taken all together,
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
4
we find that for the periods mentioned, which are
four driest months, there were 42.42 cfs more
water going into the Schoharie Reservoir than
were being sent to the Ashokan Reservoir via the
Shandaken Tunnel.
At present, full pool elevation in the Schoharie
Reservoir is 1124.5’ due to the 220’x5.5’
ungated spillway notch, forming a capacity of
about 18 billion gallons. Once the Obermeyer
Gate system is installed, scheduled for fall of
2009, full pool level will be restored to 1130’,
with a capacity of 19.583 bil. gal.. This
additional 1.5 bil. gal. ensures the ability of the
Schoharie Reservoir to meet its water supply
requirements to the Ashokan Reservoir, while
providing conservation releases to the Schoharie
Creek, north of the Gilboa Dam. Mark Twain is
quoted as saying that there are 3 forms of
falsehood...in order of magnitude: a lie, a damn
lie, and a statistic. A lot of figures have been
presented in this paper. They can all be found in
the appendix at www.dccinc.org and those who
read this paper are invited to draw their own
independent conclusions on the veracity of DCC,
Inc.’s position that sufficient water exists for
conservation releases, without impairing in any
way the quantity or quality of water discharged
through the Shandaken Tunnel. DCC, Inc. is not
asking for the coldest portion of the water
column in the Schoharie Reservoir. The fishery
of the Esopus Creek has come to depend upon
that water. Rather, the Schoharie Creek needs
flow to connect the spring fed eddies.
Furthermore, reasonable people would consent to
a temporary cessation of conservation releases,
during times of drought or other emergency of
any kind, if they were “ramped down” in an
orderly manner over a period of 12-24 hours.
Pictures at www.dccinc.org show results of the
abrupt stopping of dam spillage that occurs when
the Shandaken Tunnel discharge is suddenly
increased to full capacity.
Thus far, we have dealt with matters pertaining
to geology, the environment, hydrology and
engineering. We will now turn our attention to a
very troubling legal issue. This issue is the
agreement reached in the settlement of a case
brought by the City of New York against the
NYS Department of Environmental
Conservation, in the Supreme Court of the State
of New York, County of Albany, Index
#5840/80. It was resolved by a stipulation of
discontinuance, which means that NYSDEC
Commissioner Robert F. Flacke agreed to terms
set out by the City of New York concerning
conservation releases from New York City
owned reservoirs. In a nutshell, the “City”
would drop its case against NYSDEC if the
commissioner consented to abide by certain
stipulations. The full text of this stipulation of
discontinuance can be found at www.dccinc.org.
The second article of this agreement states that
“New York State will not at anytime require
releases from Schoharie, Ashokan or Kensico
Reservoirs, except as provided herein…”.
For several years people concerned with the
Schoharie Creek and the Gilboa Dam have heard
vague allusions to some law or agreement that
exempted NYCDEP from making conservation
releases from the Schoharie Reservoir. The
aforementioned stipulation of discontinuance is
the reason the NYCDEP has heretofore never
participated in conservation releases from the
Schoharie Reservoir. Stipulation rhymes with
capitulation and that is what it amounts to in our
eyes. For a Commissioner of the Department of
Environmental Conservation to sign such an
agreement is beyond belief. This case is to the
environment what the Dred Scott decision is to
civil rights. It is a wrong that must be righted, a
legitimate grievance that must be redressed. The
stipulation of discontinuance is 30 years old this
October and “a lot of water has gone over the
dam” in terms of environmental awareness since
1980. “Tunnel Vision” in reservoir operation is
as bad as narrow mindedness in any other
endeavor. A reasonable, intelligent exchange of
ideas can lead to an equitable sharing of the
water resources of the host or donor
communities in the Catskills and the recipients
of the vital water they require. With the
impending reconstruction of the Gilboa Dam, the
time is NOW!!!
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
5
Footnotes
1. Water Encyclopedia-Ground Water: Hydrologic Cycle, Patricia S. Irle, internet.
2. Ground Water Resources of Schoharie Co., NY, Jean M. Berdan, p. 28.
3. Ground Water Resources of Schoharie Co., NY, Jean M. Berdan, p. 27.
4. Susquicentennial Gilboa, NY, 1848-1998, Linda Trautman, Stratigos, ed., p 71.
Bibliography
Berdan, Jean M., “The Ground Water Resources of Schoharie Co. NY, Albany, NY, Bulletin G W-22.
Board of Water Supply City of NY, “Annual Report for 1925”.
Eisenberg, Lee & DeCourtney, Taylor, eds., “The Ultimate Fishing Book”, Houghton-Mifflin, Boston,
1981.
Fetter, C.W., “Applied Hydrology”, University of Wisconsin, Oshkosh, 1994.
Fluhr, T.H. & Terrenzio, V.G., “Engineering Geology of the NYC Water Supply System”, NYS Geological
Society Bulletin, Oct., 1984.
NYCDEP Bureau of Environmental Planning and Analysis, prepared by Hazen Sawyer/Gannet Flemming,
a joint venture, “Final Environmental Assessment Gilboa Dam Reconstruction, July 2008.
Simms, Jeptha R., “The History of Schoharie County and the Border Wars”, Schoharie Co. Council of
Senior Citizens, reprint 1974.
Stratigos, Linda T., “Susquicentennial Gilboa, NY 1884-1998, Gilboa Historical Society.
Titus, Robert, Ph.D., “The Catskills in the Ice Age”, Purple Mt. Press, Fleischmanns, NY, 2003.
Van Diver, Bradford B., “Road Side Geology of New York, Mountain Press Co., Missoula, Mt., 1985.
Dam Concerned Citizens, Inc. would like to express its gratitude to the United States Geological Survey
and their website, “Real-time Data of New York Stream Flow” and their many useful links.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
6
GILBOA DAM/SCHOHARIE RESERVOIR: CONCERNS, ISSUES AND PROPOSALS
Sherrie Bartholomew, President
Dam Concerned Citizens, Inc.
PO Box 310
Middleburgh, New York 12122
Dam Concerned Citizens, Inc., a citizen advocacy group, is currently focusing on issues directly related to
the renovation of the Gilboa Dam, a project that will be ongoing until 2016. Since its creation in 2005, the
paramount concern of DCC has been the rehabilitation of the Gilboa Dam and all appurtenant infrastructure
to the highest possible factor of safety. DCC's board of directors, composed of Schoharie, Montgomery and
Schenectady County residents living downstream of the Gilboa Dam, are advocates for the public before
local, state and federal government.
Issues currently being pursued by DCC include (1) a continuous, sub-surface conservation release of
reservoir water into the Schoharie Creek below the Gilboa Dam at a rate of 50-75 cfs. in times of non-
spillage, (2) establishing a consortium composed of NYSDEC, NYCDEP, PASNY, Schoharie County
Board of Supervisors, and Dam Concerned Citizens, Inc. which will develop a protocol for operating
procedures for the Obermeyer Gates ("notch") and the required Low Level Outlet to mitigate flooding and
to improve riparian habitat (3) the creation of a position of "public inspector" for the renovation work to be
done on the Gilboa Dam commencing with phase 3, and (4) the support of the generation of
hydroelectricity at the Schoharie Reservoir.
For a more in-depth description of each issue visit DCC, Inc.'s web site "www.dccinc.org".
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
7
LEARNING THROUGH EXPERIMENTS AND MEASUREMENTS: THE MOHAWK
WATERSHED AS AN OUTDOOR CLASSROOM
Jaclyn Cockburn and John Garver
Geology Department, Union College
The ideal outdoor classroom engages students, provides simple effective discovery-based
learning experiences in a setting that is familiar and accessible. Perhaps the most important
aspect of watershed studies is that students see the science as relevant and important (Balmat and
Leite, 2008). In our experience, we have found that field exercises in our courses make a
powerful impact on students. In some cases these specific problem-based field studies have
played a pivotal role in attracting students into science. An initial stumbling block for students
studying a concept for the first time is making the connection between the textbook/lecture
material and the real world. In addition, students although they attend school in Schenectady,
may not be familiar with areas beyond the campus boundaries and the issue of Novelty Space
(Elkins et al., 2008) may further impede the success of local studies. Through projects and field
trips to areas close to campus, students are able to literally put their feet on the problem and see it
for themselves. The benefit of the Mohawk Watershed is that there are a lot of processes and
activities all within a short drive of campus, or at least manageable in a day trip (southern and
western portions of the basin).
In several recent courses at Union College, students have been presented with problems or
concepts in the classroom and then taken on varying field trips in order to develop a deeper
understanding of the issue. In this paper, we discuss some of the positives and negatives in this
venture and propose areas in which these experiences can be expanded.
References
Balmat, J. L. and Leite, M. B., 2008. Interdisciplinary Undergraduate Watershed Study: An
Outdoor Classroom in the Pine Ridge Region of Northwestern Nebraska, USA; Geological
Society of America Abstracts with Programs, v. 40, n. 6, 390p.
Elkins, J.T., Elkins, N.M.L., and Hemmings, S.N.J., 2008. GeoJourney: A field-based,
interdisciplinary approach to teaching Geology, Native American Cultures, and Environmental
Studies. Journal of College Science Teaching, 37: 18-28.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
8
WEATHER AND CLIMATE OF THE MOHAWK WATERSHED
Stephen DiRienzo
NOAA/NWS Weather Forecast Office, Albany, New York
There is a relatively long record of weather observations for Albany, New York, with continuous monthly
data extending back to 1820. The Albany weather observation is taken at the Albany Airport, which is in
the Mohawk River Watershed. The Albany weather record is assumed to be a good proxy for examining
long term trends or cycles in the watershed. Weather data from the official records, which are located on
site at the National Weather Service Office in Albany, was entered into a spreadsheet for analysis.
Charting Albany precipitation, temperature and snowfall data reveals cycles on the order of 100 years in
precipitation and snowfall. These cycles appear to correlate well with past flood/drought cycles in the
watershed. In presenting these data, we will learn about past climate cycles of the watershed and the clues
they hold about possible future trends in the Mohawk River Watershed.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
9
THE HUDSON AND THE MOHAWK: WORKING TOGETHER
Fran Dunwell
Hudson River Estuary Coordinator
NYS Department of Environmental Conservation
The Mohawk River is the major tributary of the Hudson. Historically and culturally, the Hudson and the
Mohawk share common traditions influencing American life: together, the set the stage for American
victory during the Revolutionary War; they launched the American transportation revolution and
American engineering; their natural beauty became a focus of new movements in art and literature; and
together, they forged New York state into an economic powerhouse that is now memorialized in the term
Empire State. The unique natural resources, river ecosystem and geography of the Hudson-Mohawk river
system underlie all these successes.
Today, the future of these river systems is at a crossroads. Major recovery efforts have focused on the
environment of the Hudson main stem for the last 20 years. Environmental clean-up has been a major
source of economic stimulus for the Hudson Valley region. There is an opportunity to do the same for the
Mohawk, using the successful model of the Hudson River Estuary program to adopt and implement a
Mohawk River Action Agenda. This presentation will review what we can learn from the Hudson estuary
experience and will explore ways that the Mohawk and Hudson can mutually support each other, renew our
bonds of connection and write a new chapter of history for this unique river system.
Hudson River Estuary Action Agenda, seeks to
Ensure clean water
Protect and restore fish and wildlife habitats
Provide recreation in and on the water
Adapt to climate change
Conserve the scenic landscape
Through this work, the Estuary Program is helping people enjoy, protect and revitalize the Hudson River and its Valley.
For more information on the Estuary Program see http://www.dec.ny.gov/lands/4920.html
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
10
HISTORICAL LANDSLIDES AND PRECIPITATION TRENDS IN SCHENECTADY COUNTY,
MOHAWK RIVER WATERSHED, NY
John I. Garver, Amanda L. Bucci, Benjamin Carlson, Nicole Reeger, Jaclyn Cockburn
Geology Department, Union College,
Schenectady NY June, 2009
A landslide is the downslope movement of a
mass of rock, soil, or colluvium that occur on a
variety of spatial and temporal scales. Failure
occurs when the force of gravity exceeds the
strength of the surface material on a slope and
this condition is commonly facilitated by high
pore pressures resulting from saturated
conditions (Spiker and Gori, 2000). The US
Disaster Mitigation Act of 2000 resulted from
the recognition that pre-disaster planning is
necessary to reduce losses, and because of the
funding available at the state and local level, this
act has fostered an increased attention on
landslides, and other natural hazards that affect
local municipalities. While most areas of the
Mohawk watershed are not prone to landslides,
they do occur and it would appear that we are in
a period of enhanced hillslope instability. This
observation has implications for sediment
mobility and sediment availability in the
watershed. In light of this, we have undertaken a
multiyear effort to inventory landslides and
evaluate the slip history of those amenable to
study.
The New York State hazard mitigation plan
reviews a number of different hazards that the
State faces annually, all with different
probabilities and risk factors. In the NYS Multi-
Hazard Mitigation Plan, the Sate Emergency
Management Office (SEMO), defines landslides
as the downward movement of a slope and
materials under the force of gravity. This
definition includes a wide range of ground
movement, such as rock falls, deep slope failure,
shallow debris flows natural rock, soil, or
artificial fill.
In the SEMO analysis of landslides, a key issue
is the triggers that induce movement on
marginally stable slopes. These triggers, which
are naturally occurring or human-induced,
include: 1) water saturation of the ground, and 2)
mass redistribution (increased mass at the top of
a slope or removal support from the bottom).
Here we are primarily concerned with
understanding water saturation and the affect
increase in pore pressure has on slope stability
because this pre-condition has a regional effect.
Our work includes a historical survey and
scientific findings from dendro-geomorphology
conducted on several key unstable slopes in
Schenectady County, NY. Tree-rings of tilted
conifers are used here to determine the slip
history of several unstable slopes in the
watershed. Schenectady County had been
involved with ongoing landslide mitigation
efforts that started in a small but fatal slip that
occurred in downtown Schenectady in January
1996. Since that time, the county and the city of
Schenectady have been directed mitigation
efforts that were largely driven by several new
landslides that caused dramatic damage to
residential areas.
Federal mandates in the last decade have resulted
in attention being focused on disaster mitigation.
The US Disaster Mitigation Act of 2000 includes
funding for mitigation activities, developing
hazard maps, and creating a Hazard Mitigation
Grant Program (HMGP). The HMGP is a
national program in the US where counties can
apply for grant money to use towards natural
hazard mitigation and relief, provided the county
has created an All Hazard Mitigation Plan
(AHMP).
New York has a relatively low landslide
potential with the exception of failure-prone
glacial lake clays that occur widely in the
Hudson lowlands, and locally elsewhere,
especially in the Finger Lakes area. Schenectady
County, in east central New York State, has
many slopes underlain by unconsolidated
material susceptible to mass movement.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
11
Figure 1: Preliminary Landslide Susceptibility map for Schenectady County, NY prepared by the USGS,
NY State, and Schenectady County (map is unpublished but available from NY State Disaster Preparedness
Commission, 2008 and Keppel and others, unpublished). Locations of significant landslide activity in
Schenectady County that we have investigated: 1. Broadway, Tel Oil; 2. Broadway, SI plant; 3) Plotterkill
Preserve; 4) Sandsea Kill; 5) Wolf Hollow; 6) Bowman Creek; 7) Burtonsville; 8) Lisa Kill.
Figure 1: Plot showing precipitation and temperature for Albany (the longest record in the Capital
District). Precipitation is shown as the total annual (light continuous line) and a 3 yr moving average
(dark line). Shown on the graph are known periods on ground instability (starting year show). Solid gray
fields at 1972-75, 1988-89, and 2005-2009 are periods of widespread instability (recognized at more than
one location). Includes analysis or historical reports from Plotterkill, Bowman, Burtonsville, Cranes
Hollow, Broadway. This trend of wetter conditions is recognized elsewhere in the region (Burns et al.,
2007).
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
12
The city of Schenectady sits along the Mohawk
River valley, which is underlain by glacial till,
glacial lake clays, and fluvial deposits that are
then cut and incised by post-glacial erosion.
Landslides, debris flows, mudslides, and slumps
on these hillsides have occurred for some time,
but the best historical record is of those
hillslopes in and around the city of Schenectady,
Troy, and other communities.
The oldest records of landslides in Schenectady
have been partly gleaned from historical archives
and this survey work uncovered a partial history
that included specific events that occurred in
September 1853, October 1903, January 1996,
March 2004, and February 2007.
The January 1996 slide was small, but it was one
of the most significant in recent history because
it resulted in a fatality (#1, Fig. 1). With heavy
precipitation on top of snowmelt during this mid-
winter thaw, a landslide was triggered on the
Broadway slope by I-890 at the Tel Oil Co. On
March 2004, there was a landslide by the SI
Group (Schenectady International) building
located slightly to the south, also on Broadway,
just south of the Tel Oil Co. incident (#2, Fig. 1).
The SI Slip is related to a month-long period of
higher than normal precipitation and available
surface water.
In January 2008, the City was awarded FEMA
grant of $1.13 m for this project after slides
along this hill caused a number of homes at the
top (near the crown) were seriously affected.
Nearby on a slope continuous with the SI site, in
February of 2007, state contractors were clearing
debris from a culvert on a slope near the
Michigan Avenue exit (Exit 6) off I-890, a slide
occurred that buried equipment. Thus this area
is slide prone and a historical perspective of
these events is of interest to county planners
(Kalohn and others, 2007).
In the wake of all this activity, Schenectady
County participated in a unique Landslide
Susceptibility Pilot Study in 2007 in which a
landslide susceptibility map was produced for
the county (Kappel and others, unpublished; see
Fig. 1). This map has been a key factor in
focusing attention on the geology and
mechanisms of landslides in the country. On this
map, the a number of areas were mapped as
having the highest hazard, based on a
combination of five relevant factors including
soil composition, relief, and slope aspect. This
mapping project was an outgrowth of efforts
related to the development of the Schenectady
County AHMP (Kalohn and others, 2006) and
was done as a collaborative effort between N.Y.
State Emergency Management Office, N.Y.S
Geological Survey, U.S. Geological Survey, and
Schenectady County.
Our work has focused on trying to quantify both
the spatial and temporal scale of landsliding and
hillslope instability in Schenectady County. To
accomplish this inventory, we have primarily
used dendrogeomorphology to determine the slip
history of unstable slopes including active slow-
moving earth flows in these areas identified as
having high landslide susceptibility (sites 3,4,6,7
and 8 on Fig. 1).
We have focused on unstable slopes with living
(or recently killed) Tsuga canadensis (Eastern
Hemlock), as the ring record of this species is
very distinct relatively unambiguous. Tsuga
canadensis shows a clear and distinctive
response to stem tilting, which is ring asymmetry
and the production of lignin-rich reaction wood
(see Fig. 3). In most of our analysis of tilted
trees we have a 100-150 yr history of ground
movement. We emphasize that our work
continues and we are working on a number of
active slopes.
In the last century, there is a clear pattern that is
common to a number of slopes. There are
periods of inactivity and periods of activity.
Because several key active periods are common
from slope to slope, it is likely that this ground
motion was driven by rainfall-induced reduction
in pore pressure.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
13
Figure 2: Slice of Tsuga canadensis (Eastern Hemlock) that was growing on the Bowman slide, but was
then knocked over and killed in the 2008 slip event. Note that the downslope side of the conifers grow
reaction wood (dark park in the annual light-dark bands) in response to tree tilting. This tree tilted and
grew in response in 2005, and ground failure occurred in 2008 (from Bucci and Garver, 2009).
In the last century, there is a clear pattern that is common to a number of slopes. There are periods of
inactivity and periods of activity. Because several key active periods are common from slope to slope, it is
likely that this ground motion was driven by rainfall-induced reduction in pore pressure.
The last decade has been the wettest ten-year interval in Albany NY since 1878 as revealed by NOAA
records. In addition, the Northeast has seen an increase in the number of extreme precipitation events –
defined as total precipitation per event > 2 in (Frumhoff and others, 2007). We have seen from the data
that there is currently enhanced movement on hillslopes since 2005. Together, these findings would imply
that we are entering a period of enhanced hillslope instability, similar to the 1970’s, if not more dramatic.
Our data seem to suggest that in part some of this hillslope instability is a result of reactivating material
previously mobilized in the early 1970’s. Simply put, this conclusion would suggest that hillslopes with a
history of instability should be monitored closely for renewed activity.
References
Bucci, A.L., and Garver, J.I., 2009. Timing of slumping determind from growth asymmetry in Tsuga
canadensis, Mohawk River watershed, NY; Geological Society of America Abstracts with programs, v. 41,
n. 3, p. 26.
Burns, D.A., Klaus, J., and McHale, M.R., 2007, Recent climate trends and implications for water
resources in the Catskill Mountain region, New York, USA: Journal of Hydrology, v. 336, no. 1-2, p. 155-
170.
Frumhoff, P.C., McCarthy, J.J., Melillo, J.M., Moser, S.C., and Wuebbles, D.J., 2007, Confronting Climate
Change in the U.S. Northeast: Science, Impacts, and Solutions. Synthesis report of the Northeast Climate
Impacts Assessment (NECIA). Cambridge, MA: Union of Concerned Scientists (UCS), 146 p.
Kappel and others, Preliminary Landslide Susceptibility map for Schenectady County, NY prepared by the
USGS, NY State, and Schenectady County.
Kalohn, J., and many others, 2007, Schenectady County Multi-Jurisdictional All Hazard Mitigation Plan,
Schenectady County Department of Economic Development and Planning, 285 p.
NY State Disaster Preparedness Commission, 2008, New York State Comprehensive Emergency
Management Plan - Standard Multi-Hazard Mitigation Plan, unpublished (plan available at:
http://www.semo.state.ny.us/programs/planning/hazmitplan.cfm
Spiker, E.C. and Gori, P.L., 2000, National Landslide Hazards Mitigation Strategy: A Framework for Loss
Reduction: U.S. Geological Survey Open-File Report 00-450, p.49.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
14
USE OF HIGH-RESOLUTION LIDAR IMAGES TO IDENTIFY SLOPES WITH
QUESTIONABLE STABILITY ALONG THE MOHAWK RIVER BANKS
Ashraf Ghaly, Ph.D., P.E.
Professor of Engineering
Union College, Schenectady, NY 12308
ghalya@union.edu
(Oral Presentation)
High-resolution LiDAR images for the Mohawk River watershed were made available by the New York
State Department of Environmental Conservation. With the aid of Geographic Information Systems (GIS),
the slopes and aspects of the terrain within the Mohawk River’s watershed and along its banks were derived
from the LiDAR images. This process helps identify the slopes with critical or questionable stability that
are in need for stabilization to avoid the hazard of landslide. The level of detail that LiDAR images exhibit
can make the task of identifying the slopes with urgent need for attention reasonably accurate. It is a
process that can be highly productive relative to field inspection and instrumentation, which requires the
installation of devices and making measurements at locations of questionable stability. The benefits of such
an analysis are the ability to analyze large volume of data that covers wide-spreading area with
significantly less effort and time. Furthermore, early identification of potentially hazardous locations can
help alleviate possible problems and damages in a timely fashion. This can potentially reduce the threats of
sudden failure of embankments, structures, or roads.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
15
METHODS AND TECHNIQUES OF STABILIZATION OF SOIL SLOPES
Ashraf Ghaly, Ph.D., P.E.
Professor of Engineering
Union College, Schenectady, NY 12308
ghalya@union.edu
(Poster Presentation)
There exist numerous techniques that can be utilized to stabilize a soil slope. Techniques vary considerably
and the costs associated with them also vary significantly. Some of these techniques are as simple as
planting a layer of deep-rooted vegetation on a potentially hazardous slopes, or as sophisticated as using
tie-backs in conjunction with reinforced soil techniques. The use of geosynthetics for slope stabilization has
also been implemented successfully in a variety of situations where drainage, filtration, and/or
reinforcement were required. The need to ensure slope stability is coupled with the continuous exposure of
scour and erosion that could endanger infrastructure facilities constructed along or across a river, such as
the Mohawk. Facilities such as dams, bridges, piers, abutments, and roads could be impacted and even
damaged if soil slopes were inadequately stabilized. This presentation will offer insight into various
stabilization techniques, together with effective ways of implementation in a variety of situations and
applications. In addition to the technical aspect of this subject, economic considerations and feasibility
issues will be also factored.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
16
COLLOIDAL CONCENTRATION ESTIMATION USING ADCP ECHO INTENSITY
William Kirkey1, Chris Fuller1, James S. Bonner1, Temitope Ojo1, Mohammad Shahidul Islam2
1Clarkson University
Potsdam, New York 13699
2Beacon Institute for Rivers and Estuaries
Beacon, New York 12508
Suspended sediment concentration (SSC) plays a major role in determining the physical and biological
characteristics of river systems. For example, sediment settling often necessitates dredging to maintain
adequate depth in ports and channels. Also, many pollutants, such as polychlorinated biphenyls (PCBs),
have a high affinity for sediment particles, making the transport of suspended sediment the primary means
of dispersing such chemicals throughout the watershed (Orton, 2001). Recently, there has been interest in
using acoustic doppler current profilers (ADCPs) to monitor suspended sediment concentrations (SSC)
(Wall, 2006). The use of ADCPs for this type of measurement permits simultaneous multipoint
measurements with high spatial and temporal resolution, as opposed to conventional single-point SSC
measurements. Additionally, the combination of SSC measurements with identically resolved ADCP water
current measurements enable the computation of suspended sediment discharge. However, because ADCP
SSC measurements are based only on the intensity of reflected acoustic waves, they cannot elucidate any
information on particle size distribution. Further, this echo intensity is a function of both SSC and size
distribution. As such, using an ADCP to measure SSC requires either measurement or accurate assumption
of particle size distribution.
Laser In-Situ Scattering and Transmissometry (LISST) is a technique, which uses laser diffraction
to determine particle size distribution as well as overall SSC at a single point. In order to correlate ADCP
echo intensity with LISST measurements, both types of instruments must be deployed within the same
water column. Autonomous moored profiling sensor platforms, in which a suite of sensors is robotically
maneuvered in order to monitor water quality at a range of depths, are ideal for such a deployment. Two
such monitoring stations were developed and deployed during 2009 as part of the Rivers and Estuary
Observatory Network (REON) operated by the Beacon Institute for Rivers and Esturaries in partnership
with Clarkson University. With these platforms, the spatial and temporal measurement frequency can be
specified as needed, provided that ample solar power is available to sustain the desired measurement rate.
The data is automatically collected and archived, and visual data is available on the World Wide Web at
www.bire.org. One platform, shown in Figure 1, was deployed in the Hudson River near Beacon, NY, and
the other in the Grasse River (a tributary to the St. Lawrence River) in Massena, NY. Each profiling system
is presently equipped with a particle analyzer (LISST-100x, Sequoia), a fluorometer (FL3, Wetlabs), a
conductivity/temperature/depth (CTD) analyzer (SBE37, Seabird), and a dissolved oxygen probe (Optode,
Aandera). In addition, each platform includes a meteorological monitoring unit (RM Young or Maretron)
and a downward-looking ADCP (Workhorse, RDI Instruments). The presence of the LISST provides both
particle distribution information needed to extract SSC from the ADCP echo intensity data and a direct
measurement of SSC with which to compare the calculated results. At the same time, the ADCP augments
the LISST by recording SSC simultaneously throughout the water column, rather than point-by-point.
The echo intensity measured by an ADCP is a function of both the particle size and concentration and thus
provides the theoretical basis for measuring SSC. This study shows depth specific echo intensity from a
2400 kHz ADCP to be linear on a semi-log scale to colloidal clay suspension mass concentration standards
dispersed in an outdoor test tank. Both the linear slopes and correlation coefficients increased with
proximity to the ADCP as a result of signal attenuation from beam spreading and water absorption. The
empirical relationship between the measured echo intensity and total volume concentration is evaluated
with respect to the theoretical echo intensity derived from the Rayleigh scattering equation and the
empirical particle size distribution determined with a LISST instrument, as shown in Figure 2. This
analysis provides a framework for computation of SSC from in-situ ADCP data guided by corresponding
LISST data.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
17
References
Orton, P.M. and Kineke, P.C., 2001. Comparing calculated and observed vertical suspended-sediment
distributions from a Hudson River estuary turbidity maximum. Estuarine, coastal, and shelf science, 52,
401-410.
Wall, G.R., Nystrom, E.A., and Litten, S., 2006. Use of an ADCP to compute suspended-sediment
discharge in the tidal Hudson River, New York. USGS Scientific Investigations Report 2006-5055.
Figure 1: REON platform deployed in the Hudson River near Beacon, NY (Spring 2009).
Figure 2. Measured ADCP echo intensity versus predicted Rayleigh-scattered acoustic amplitude for
various SSC standards as recorded by a specific ADCP bin.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
18
THERMAL CHARACTERISTICS OF THE SCHOHARIE CREEK AND ITS ROLE IN THE
REINTRODUCTION OF BROWN TROUT (SALMO TRUTTA)
V. Ashley Kovack, Jaclyn Cockburn and John Garver
Union College, Schenectady, NY
The Schoharie Creek drains the north-facing portion of the Catskills Mountains and is a tributary to the
Mohawk River. Currently a small portion of the river is suitable habitat for Brown trout (Salmo trutta).
Water temperature is the major limiting factor in trout habitat, as it requires cool well-oxygenated water.
The upper limiting lethal water temperature for adult Brown trout is 27.2˚C, with optimal water
temperature ranging from 7 to 19˚C for all life stages. In this study, continuous water temperature, air
temperature, and discharge for four locations in Schoharie Creek were collected during summer of 2009.
Findings indicate large discharge events greater than 5 million m3 (average discharge ~20 m3/s) moderate
the thermal regime of the stream resulting in cooler water temperatures. In parts of the river where there is
little to no runoff, the water temperature follows the air temperature, frequently exceeding 27˚C, and is
therefore uninhabitable. The lower reaches of the river had the warmest water levels, although the very
uppermost part of the stream was warm due to low or no flow through the middle of July and end of August
2009 (Figure 1). Trout habitat could be expanded if higher flows during the warmest months of the year
were ensured to provide sufficient flow and temperature conditions. Higher water volumes are possible
with a guaranteed cold-water release from the Schoharie Reservoir, but require negotiation with New York
City Department of Environmental Protection.
Figure 1: Discharge and water temperature at 990V Bridge (upper watershed) and at Burtonsville (Currie
Farm) June – August 2009. The ideal range of temperature for trout is between 7oC and 19oC and for most
of July and August water temperature is well above the upper limit.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
19
A LATE HOLOCENE RECORD OF MOHAWK RIVER FLOODING PRESERVED IN A
SEDIMENT CORE FROM COLLIN’S POND IN SCOTIA, NEW YORK
Mark Krisanda, Jaclyn Cockburn, Donald Rodbell
Geology Department, Union College, Schenectady NY
Collin's Pond is a small, dimictic pond on the floodplain of the Mohawk River in Scotia, NY (Figure 1).
The sedimentary record indicates sedimentation rates increased drastically from ~138cm/1000yr to
~789cm/1000yr at approximately 1200AD (Figure 2). This large increase in rate may be indicative of
increased ice jams or summer floods in the Mohawk River. The sediment record has discrete, normally
graded medium sand to silt laminae that are intercalated with massive, organic-rich sediment. Many of
these laminae possess erosional basal contacts, and some contain rip-up clasts of fine-grained organic
sediment. These characteristics suggest that density-driven undercurrents caused by Mohawk River
flooding may have deposited the clastic layers. The bottom of the core contains wood fragments overlain
by a layer of coarse sand, which likely marks the formation of Collin's Pond (~4128yr BC). The frequency
of flood lamiae decreases at ~1500AD, which may reflect decreased flood frequency of the Mohawk River.
At ~1850AD, the core records a pronounced increase in organic carbon content, which likely reflects
cultural eutrophication of Collin's Pond, and construction of a levee between the Mohawk River and the
Pond that reduced clastic sediment input from the Mohawk River.
Figure 1: Collins Pond relative to the Mohawk River and Village of Scotia (Ruggiero et al., 2000).
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
20
Figure 2: Downcore data analyzed in the 2009 Collin’s Pond sediment core. The age-depth model is based
on a variety of radiocarbon dates collected from this sediment core and previous studies (see poster for
details). The sediments have coarse reddish layers that were interpreted as material flushed into the ponds
during high-water events on the Mohawk River and are characterized by high bulk density and magnetic
susceptibility. The horizontal bands in the figure represent the location of these deposits in the sedimentary
record. Increased sedimentation rate between 1242 AD to 1800 AD is attributed to increased storminess in
the northeast related to the Little Ice Age. Higher sedimentation rates in the last two centuries is likely due
to anthropogenic activities - canalization of the Mohawk River and eutrophication of the water column.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
21
MOHAWK RIVER: ERIE CANAL; ITS ONE IN THE SAME
Carmella R. Mantello1 and Howard M. Goebel2, P.E., P.H.
1Director of the New York State Canal Corporation
2Canal Hydrologist
The Mohawk River and the Erie Canal have
shared an interwoven connection since the Erie
Canal was constructed in 1825 as “Clinton’s
Ditch”. Eastern portions of the original Erie
Canal and the 1862 and 1895 enlargements
represented a static canal constructed essentially
parallel to the Mohawk River. The Mohawk
River flowed freely with overflows from the
adjacent canal discharging to the river.
The existing Erie Canal, originally referred to as
the Barge Canal, was constructed between 1905
and 1918. Construction of the Erie Canal took a
much different approach than the prior “canals”,
utilizing rivers to develop a dynamic canal and
create a new canal for a new age. The Erie
Canal, from its beginning in Waterford, NY, to
the summit level in Rome, utilized major
portions of the Mohawk River to create the
navigable waterway. The challenge of this
approach was how to functionally utilize a free
flowing river as a navigable canal over the full
range of hydrologic extremes observed in the
Mohawk Watershed.
A system of Mohawk movable dams borrowed
from the Czech Republic made taming the
mighty Mohawk River possible, while allowing
for the free flow of water and ice during the
winter.
The Erie Canal’s lifeline is water, and it cannot
be operated without it. The Barge Canal Act of
1903 began the appropriation of lands and waters
necessary to operate the canal and in the
Mohawk River Basin, Hinckley and Delta
Reservoirs were constructed as the primary
source of water.
These reservoirs are managed to maintain water
levels on the downstream canal to provide
necessary water depths and overhead clearances
required to uphold the State’s Constitutional
obligation to maintain a navigable channel.
The Canal Corporation provides an extensive
water management program aimed at providing
navigable pools at each lock conducive to
navigation throughout the navigation season.
Water levels and gate openings throughout the
Erie Canal are routinely input into the Canal
Infrastructure Management System. These data,
coupled with short- and long-range weather
forecasts, are utilized for proactive and reactive
management of the system.
The Erie Canal also serves as a catalyst for
economic development throughout the Mohawk
Valley region. In the past decade, the Canal
Corporation has undertaken capital projects that
enhance and promote tourism, recreation,
historic interpretation, and community
revitalization. The Canal Corporation has
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
22
partnered with other state agencies to focus on
canal-related programs and projects to benefit
the community and raise awareness of the
benefits of being a canal community.
Further community development and
intergovernmental partnerships are being
initiated in the Mohawk Valley through the
Corporation’s Community Development Team.
This Team provides enhanced technical
assistance for communities to promote public
access and link the communities to the canal.
One major initiative in the Mohawk Valley
includes the Erie Canal Greenway Grant
program. This program is providing grant
funding in Schenectady for public access
facilities with docks and waterfront park
improvements, a Canal Community
Infrastructure Project in Rome, and expansion of
harbor services at the Rome Bellamy Harbor, St.
Johnsville public docking facilities, and
construction of the Fort Plain Welcome Center at
the Fort Plain Public Library. In addition, Fonda
Waterfront Park, Schenectady Mohawk-Hudson
Bike Hike Trail/Erie Canalway Trail and the
Canastota to Rome Canalway Trail projects are
being realized through these efforts.
The Canal Corporation is also a major sponsor of
the World Canals Conference 2010 (WCC),
scheduled to take place in Rochester during the
week of September 19, 2010. During the nearly
week long conference, the Erie Canal will take
center stage as hundreds of canal enthusiasts
from around the world will convene in Rochester
to experience all that New York's Canal System
has to offer and to showcase the investments
New York State has made in the Canal System
during the past decade.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
23
MAPPING AND VOLUMETRIC CALCULATION OF THE JANUARY 2010 ICE JAM FLOOD,
LOWER MOHAWK RIVER, USING LIDAR AND GIS
Marsellos, A.E.1,2 , Garver, J.I.2, Cockburn, J.M.H.2
1 Dept. of Atmospheric & Environmental Sciences, State University of New York, Albany NY 12222, New
York, U.S.A., email: marsellos@gmail.com
2 Dept. of Geology, Union College, Schenectady, NY 12308, New York, U.S.A
Ice jams are an annual occurrence on the
Mohawk River (Johnston and Garver, 2001;
Lederer and Garver, 2001; Scheller and others,
2002; Garver and Cockburn, 2009). As a
northern temperate river, ice jams are expected
and the lower Mohawk is particularly vulnerable
to jams and the hazards associated with them.
Breakup involves ice floes that commonly form
ice jams (or dams) that occur when the frozen
river breaks up and the moving ice gets stuck due
to restriction of flow at channel constrictions and
areas of reduced flood plain. Historically we
know that the time of ice out and ice jam
formation occurs on the rising limb of the
hydrograph, when the floodwaters are building.
When flow starts to rise it is not uncommon for
unimpeded ice runs to develop, but invariably
the ice gets blocked or impeded along the way by
constrictions in the river, especially where the
flood plain is reduced in size.
An important issue in understanding ice jams
and where they form is how much water can get
backed up behind ice dams that block the flow of
the water (see Robichaud and Hicks, 2001;
White and others, 2007). It is typical for these
features to form, but then break up as water
levels increase (Jasek, 1999). In a sense they are
self regulating because rising water causes the
ice jam to float, which ultimately results in self
destruction. When this does occur, there is an
ice jam release wave that propagates downstream
(Watson et al., 2009). This release of water can
itself cause flooding, and it is clearly recorded as
an increase in instantaneous discharge
downstream. In fact, in many break up floods,
the highest instantaneous discharge is in fact a
surge that has resulted from the release of an ice
jam. The highest instantaneous discharge
recorded on the Mohawk River (143k cfs),
resulted from just such an event in March 1964.
The mid-winter break up event of 25-26 January
2010 caused significant ice jams to form in the
lower part of the Mohawk River. Moderately
warm temperatures and heavy rain from a south-
to north-tracking Atlantic storm caused
considerable melting and rapid increase in
discharge on the Mohawk River and its main
tributaries, especially Schoharie Creek, which
drains the northern Catskills. The highest
rainfall amounts were in the headwaters of the
Schoharie Creek and were ~5 inches, but
elsewhere in the lower basin totals were only
about 1 inch. Although rain and melting
occurred in the upper parts of the drainage basin,
the effects were limited.
January 2010 Ice Jam
Ice accumulation and maximum water levels
suggest that the main jam occurred at the Boston
and Maine (B&M) rail bridge, which crosses the
Mohawk River from Glenville to Rotterdam
Junction. The western part of this bridge is
essentially on the edge of the SI plant, which had
constant monitoring of water levels and video
surveillance of the ice. From the video record it
is clear that after several minutes of re-
adjustment, and a rapid water rise of about 1
foot, the jam released at 09:44 AM on 26
January. Following this release, there was rapid
and continuous movement of the ice floe down
the Mohawk, and a sharp reduction in water
levels. The highest level recorded at the SI plant
was 244’ at their independent observation
station.
Because it appears that the front of the release
wave made it from Rotterdam Junction
downstream to Cohoes (39 km) by 11:00 AM
(26 Jan), this would suggest that the front of the
release wave travelled at an average rate of 31.2
km/hr (19.4 mph) over that entire distance. We
estimate that the jam first formed at the B&M
rail bridge at or before 11:45 PM on 25 January.
At this point we consider the volume of water
that was backed up in the ice jam, and to do this
we calculate the volume of the ice jam release
(from the hydrograph downstream) and we use a
LiDAR topographic model in the flooded area to
estimate the volume of backed up water (Figure
1).
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
24
Figure 1: Flood Map where it shows the flood affected area. The flood took place on the 25-26th January
(2010) due to the ice-dam that formed in this constricted part of the floodplain. Volumetric calculation
results are shown for each sector on the map.
LiDAR volumetric calculation model
Here we test whether flood model applications
using LiDAR are successful where topographic
relief is low and changes occur gradually. Such
digital elevation models (DEM) are particular
useful for flood simulation in rural or urban
areas. Although important topographic features
and properties are not simulated explicitly by
Air-LiDAR (such as trees) ground points provide
a very realistic digital elevation model of
decimeter accuracy. In urban areas, features like
roads or buildings have an important effect on
flooding and as such must be accounted for in
the model set-up.
An accurate calculation of the flood volume
requires a digital elevation model of less than 1-
meter accuracy. In this study we calculated the
volume between the flood plain and the
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
25
maximum elevation of the ice jam induced flood
on January flood from field observations and a
LiDAR developed DEM of 0.11 m accuracy.
Buildings, affected trees and other existing
infrastructure were used to determine the
maximum flood elevation.
The flooded study area is located between the
New York State Canal System Lock 9 (E9 Lock)
and the B&M Rail Bridge at the Schenectady
International (SI) Plant (Figure 1). A DEM with
grid size of 0.11 m grid was generated from
LiDAR data and served as a base line case for
various flood simulations. Ideally data
processing is supported by a field survey to
obtain specific observations and elevation
measurements of highest observed water levels
(Figure 2). Due to the low gradient of the flood
plain, the elevations of the high water mark was
estimated in two different target areas. The river
area has been delineated using the lowest
elevation values, which are essentially bank full
conditions (67 m). The lack of information about
river levels prior to jamming makes it difficult to
fully assess the volumetric calculation, but bank
full conditions are a reasonable starting estimate.
For this reason, the two target polygon areas
were subtracted by the river’s polygon (clipped).
However, in this study we present the volumetric
calculation for both target areas of the river area
as separate numbers (Figure 1). The volumetric
calculation that took place on the Mohawk River
had a 67 m water elevation base line of the river
and the flood at 73.45 m and at 74.40 m water
elevation, respectively for the two target areas.
The main methods that were used to specify the
flooded areas were raster to feature process with
a prior reclassification of the water values.
The volumetric calculation of the flood has
shown that the northwestern portion of the area
(near the E9 Lock) was flooded by 722,054 m3 of
water (Figure 1) covering an area of 301,233 m2.
The southeastern portion of the area flooded
(from the Skydive restaurant to the Chemical
Plant) was flooded by 1,087,775 m3 covering an
area of 525,601 m2. Assuming that the water
level at the river before the ice-dam formation
was 67 m then the river was flooded by
2,806,426 m3. The maximum volume of water
that flooded the land derived from the flood of
the 24-25th of January caused by the ice-dam
between the E9 lock station and the Chemical
Plant was 1,809,829 m3, and it covered an area
of 826,834 m2. Therefore the estimate of the
total volume delayed by the ice jam was
approximately 4.6 million m3 using volumetric
calculations based on LiDAR-derived
topography.
Figure 2: (a) Field observations from the E9
Lock station; (b) water flood model derived from
the LiDAR DEM (0.11 m resolution) to
determine the accurate flood elevation level.
Hydrograph Separation
A volumetric comparison of the LIDAR based
flood volume calculation was conducted using
USGS stage and discharge data from the Cohoes
Falls station on the Mohawk River (USGS
01357500). Hydrograph separation is a
common method used to determine the runoff
volume for a given hydrograph component.
Graphical separation is the simplest technique
and is used extensively in simple runoff events
(Singh, 1992). To determine the volume of
water released after the jam broke on Jan 26, a
straight line was drawn from the time the
hydrograph rose rapidly (~11:00am) to intersect
with the falling limb of the hydrograph (Figure
3). The slope of this line approximated the slope
of the rising limb, prior to jam formation and
intersects the falling limb at 3:45pm on Jan 26.
It was estimated that 0.0047 km3 of water (4.7
million m3) was delayed by the ice jam, by
calculating the area between the hydrograph and
the straight line. Graphical separation is
admittedly simple and has the potential to over
or under estimate volumes of flow, but given the
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
26
data available this method was the most
appropriate for the January 26, 2010 ice jam.
Figure 3. Hydrograph and water level (stage) in
the 2010 event (from Cohoes Falls, NY).
Estimation of the volume of water that surged
through the system is c. 4.7 million m3.
Conclusions
As ice jams form and break-up there are clearly
critical thresholds that are reached that ultimately
cause the self-destruction of the ice front. Our
calculations of the volume of the flooded area
(4.6 million m3), and the volume of water
recorded downstream using hydrographic
separation (4.7 million m3), are, remarkably, in
agreement. We suspect continued studies of
volume of water behind ice jams in different
reaches of the lower Mohawk River will shed
light on the critical thresholds for ice build-up
and the effects of the release of water
downstream (i.e. Brufau, P. and Garcia-Navarro,
P., 2000; Nzokou et al., 2009).
Figure 4: (a) The flooded area as it appears
around the Skydive Restaurant in the morning of
the 26th of January; (b) LiDAR 3D representation
of the flooded area shown by the blue color.
A key piece of data that is required in the future
is a real-time monitoring network using pressure
transducers that can provide fast reliable data on
the condition of the ice movement along several
key parts of the river that are prone to ice
jamming (Robichaud and Hicks, 2001; White et
al., 2007).
References
Brufau, P. and Garcia-Navarro, P., 2000, Two-dimensional dam break flow simulation. International
Journal for Numerical Methods in Fluids, 33(1), p. 35-57.
Garver, J.I., and Cockburn, J.M.H. 2009. A historical perspective of Ice Jams on the lower Mohawk
River. In: Cockburn, J.M.H. and Garver, J.I., Proceedings from the 2009 Mohawk Watershed
Symposium, Union College, Schenectady NY, p. 25-29.
Jasek, M., 1999, Analysis of ice Jam Surge and Ice Velocity Data, Proceedings of the 10th Workshop on
the Hydraulics of Ice Covered Rivers, Winnipeg, pp. 174-184.
Johnston, S.A., and Garver, J.I., 2001, Record of flooding on the Mohawk River from 1634 to 2000 based
on historical Archives, Geological Society of America, Abstracts with Programs v. 33, n. 1, p.73.
Lederer, J.R., and Garver, J.I., 2001, Ice jams on the lower Mohawk River, New York: Lessons from recent
breakup events. Geological Society of America, Abstracts with Programs v. 33, n. 1, p. 73.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
27
Nzokou T.F. Morse B., Robert J.-L., Richard M., Tossou E., 2009, Modeling of dam break wave
propagation in an ice-covered channel; CGU HS Committee on River Ice Processes and the
Environment 15th Workshop on River Ice St. John’s, Newfoundland and Labrador, June 15 - 17,
2009, p. 238-249.
Robichaud and F. Hicks, 2001, Remote Monitoring of River Ice Jam Dynamics. Proceedings of the 11th
Workshop on the Hydraulics of Ice Covered Rivers.
Scheller, M., Luey, K., and Garver, J.I., 2002. Major Floods on the Mohawk River (NY): 1832-2000.
Retrieved March 2009 from http://minerva.union.edu/garverj/mohawk/170_yr.html
Singh, V. P. 1992. Elementary Hydrology. Prentice Hall, Englewood Cliffs, NJ, 973p.
Watson, D., Hicks F., and Andrishak R., 2009. Analysis of Observed 2008 Ice Jam Release Events on the
Hay River, NWT, CGU HS Committee on River Ice Processes and the Environment 15th
Workshop on River Ice, St. John’s, Newfoundland and Labrador, June 15 - 17, 2009, p. 316-330.
White, K.D., Hicks, F.E., Belatos, S., Loss, G, 2007, Ice Jam Response and Mitigation: The Need for
Cooperative Succession Planning and Knowledge Transfer, Proceedings of the 14th Workshop on
the Hydraulics of Ice Covered Rivers.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
28
DETERMINATION OF HISTORICAL CHANNEL CHANGES AND MEANDER CUT-OFF POINTS
USING LIDAR AND GIS IN SCHOHARIE CREEK, NY
Marsellos, A.E.1,2, Garver, J.I.2, Cockburn, J.M.H.2, Tsakiri, K.G.3
1 Dept. of Atmospheric & Environmental Sciences, State University of New York, Albany
NY 12222, New York, U.S.A., email: marsellos@gmail.com
2 Dept. of Geology, Union College, Schenectady, NY 12308, New York, U.S.A
3 Dept. of Mathematics & Statistics, State University of New York, Albany
Introduction
The lower reach of the Schoharie Creek
(Fig. 1) takes an unusual route through a
glaciated bedrock high (now Lost Valley) and
then a significant reach underlain largely by
glacial till before the confluence with the
Mohawk River. During the Recent evolution,
this section of the river has incised downward,
likely to keep pace with downward incision of
the Mohawk River. The objective and the scope
of this work is to utilize LiDAR data to construct
a bare-earth model that allows identification of
subtle terrain features such as abandoned
channels and landslides. These
geomorphological features reveal a complex
history of incision and avulsion in the lower
reaches of Schoharie Creek.
Bare-earth model
Light detection and Radar (LiDAR) is
used to generate high-quality digital elevation
data. These highly accurate topographic data can
be used to analyze flood hazards, and to
delineate floodplain boundaries because the
topography is revealed in incredible detail.
LiDAR sensors utilize a laser pulse (typically
between 0.5 and 1 meter in diameter) and a pulse
length (a short time of the laser pulse). LiDAR
sensors are capable of receiving multiple returns,
commonly up to five returns per pulse.
Thousands of returns per second can be recorded
classifying targets according to the number of
returns. When a laser pulse hits a soft target (e.g.,
a forest canopy), the first return represents the
top of that feature representing the top of this
feature. However, a portion of the laser light
beam likely continues downwards below the soft
target and hit a tree branch or the ground below a
tree. This would provide a second return.
Theoretically, the last return represents the bare
earth terrain. A classification of the points with
the highest number of returns could reconstruct
the ground surface (e.g. a TIN surface), while the
rest of the points with lower number of returns
could represent anthropogenic structures or
forest canopy. Surface water (lakes or rivers)
does not return laser light and therefore a void is
created that shows the outline of a current river
channel or lakes.
Methods
The collected LiDAR data have a
resolution of greater than 12 pts per m2 providing
a resolution in the gridded data at 0.25 m or less
(commonly 0.09 m). The point cloud data has
had minimal processing to eliminate outliers,
from reflections etc. Larger areas with outliers or
reflection have been manually subtracted and
interpolated with the surrounding data points
(this process mainly affects the river channel).
The high-resolution topographic images
that show bare-earth LiDAR-derived topography
are made by subtracting the canopy and defining
a "bare-earth" elevation model using only the
classified ground-points (Fig. 2) to identify
evidence of the evolution of incision revealed by
abandoned channels. Avulsion and subsequent
abandonment of fluvial channels is analyzed by
geomorphic mapping of these high-resolution
topographic data (Fig. 3).
To facilitate viewing, interpretation and
post-processing of the point cloud data 3D
elevation models were constructed with
examination of water levels in the TIN model
(e.g. Fig 2). The flood plain area has been
evaluated by the mapping highest elevated
abandoned channels. A water level plain surface
at 120 m in the TIN has specified as the TIN
flooded area. The TIN flooded area has been
converted to polygon features clipping the flood
plain coverage. The path of the Schoharie Creek
has been extracted by delineating the gap area
from the LiDAR points. The abandon channel
features have been extracted from the TIN model
derived by the ground points. Those successive
abandon channels have been classified according
to the distance from the current creek location,
and then connected to reconstruct historical
pathways of the Schoharie Creek. All the
extracted linear features from those historical
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
29
pathways have had same beginning and ending
points, and their distance was measured.
Results
In Schoharie Creek, delineation of a series
of successive abandon channels shows a clear
evolutionary trend in this part of the river of
successive channel formation and abandonment
(Fig. 3, 4). There are at least three different
channel deviation and incision times (Fig. 5).
The succession of these channels helps to
identify the principal trends (see Fig. 3) of the
migration of meander bends that areas are
currently used for agriculture. An important
question that emerges from this analysis is the
primary driving mechanism caused channel
avulsion.
In the study area, the present current creek
length is 9.0 km. The length measurements of the
three successive channel deviations are 10.1,
11.2, and 12.2 km. In the same floodplain area
the three reconstructed paleomeanders show a
~30% decrease of their length. The successive
meander changes of their length (Fig. 5) show a
linear association that may allow a broad
prediction for the future meander length. This
study is a first step in using high-resolution
LiDAR data to Quantify Landscape evolution in
the Mohawk watershed. Future analyses may
include dating techniques to understand the
temporal pace of these changes so that they may
be linked to basin-wide processed.
Table 1: Meander length measurements (km) of different generations with the relative change (%).
Prediction of the future has derived from a linear equation (y= -1.06x + 13.31).
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
30
Fig. 1: Aerial view from the study area of the Schoharie Creek (from Google Earth).
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
31
Fig. 2: TIN model derived from LiDAR ground points (bare-earth model)
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
32
Fig. 3: Classification of oxbows and abandon channels as segments of older meanders.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
33
Fig. 4: A portion of the LiDAR bare-earth model that shows the successive abandon channels in 3D.
Fig. 5: The length of the present river path that appears to decrease by about ~10%.
Abandon channels
Schoharie Creek
3D - section
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
34
THE ENVIRONMENTAL STUDY TEAM PROGRAM: ENGAGING YOUTH AND THEIR
COMMUNITIES IN WATER QUALITY MONITORING OF THEIR LOCAL FRESHWATER
STREAMS, LAKES AND RIVERS
John McKeeby1, Caitlin McKinley2 and Zachary McKeeby2,
1Executive Director, Schoharie River Center
2EST members and students at Duanesburg School District
As new “regional” approaches in the
management of the Mohawk River Basin
Watershed grow and take shape through recent
state and regional initiatives. A key component
for the successful implementation of regional
watershed management planning is developing
strong local community based support and
involvement in coordinated watershed
management efforts. However, obtaining local
community buy- in and local stakeholder
cooperation to promote watershed management
initiatives that may have benefits primarily
outside of their local area, can sometimes be
difficult. Especially now, as communities and
local governments face a myriad of economic
challenges as they struggle to maintain basic and
mandated services to local residents, (the
downturn in the economy and resulting decreases
in tax revenues, the loss of state aid while the
costs of necessary services continue to increase),
the costs of voluntary compliance with regional
watershed management requirements can seem
to outweigh the benefits for some local
communities. Often the educational, social
welfare and local quality of life benefits possible
through coordinated activities, that promote both
effective watershed management planning, and
community development and citizen
engagement, goes unrecognized and
underutilized at local levels. Engaging a broad
range of community organizations and non-
profits, schools, youth service agencies, and the
youth and families they serve in a local
community can be an effective and efficient
strategy in creating local support for watershed
planning and management at the local level.
The Schoharie River Center’s Environmental
Study Team Program (EST) is an effective, cost
efficient and easily replicable program model for
engaging and building community interest and
support in local water quality issues and
promoting local stakeholder interest in regional
watershed management planning and education.
The SRC - EST program works closely with
local youth (ages 13 – 18) their parents, and the
community organizations that serve them (grass
roots organizations, schools, afterschool
programs, county youth bureaus, social service
agencies, etc.), as well as watershed management
professionals, County SWCD, and local colleges
and universities, to integrate youth development
skills programming, field biology, and general
science education into an experientially based
year-round program that promotes that values of
community based environmental conservation
and stewardship, and support academics, drop-
out prevention and youth development skills and
career exploration. Utilizing a broad based
approach encompassing training and ongoing
programming in local water quality monitoring,
sustainable forestry agriculture – maple syrup
making, community based archeology, academic
enrichment, out-door recreation - cross country
skiing, hiking, swimming, SCUBA, sailing, etc.
The EST program model is successful in
engaging a wide variety of youth and
communities, developing locally based out-door
education programming which encourages local
youth and adults to become knowledgeable about
and involved in the protection and stewardship
of their local environment and freshwater
resources. Successfully leveraging program
funding from a diverse group of stakeholders
(environmental & conservation organizations,
education, social services, and private non-profit
foundations) the program has broad appeal due
to its holistic, and long term approach; engaging,
training and utilizing the energy, natural
curiosity and passion for learning of youth (a
renewable natural resource) to study, monitor,
protect, enjoy and improve their local
environment and freshwater resources. The
program provides a link between professional
freshwater water resource managers, college and
university researchers and local youth and
community members residing in the watersheds
under study.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
35
The EST program is flexible and easily adapted
to local community interests, organizational
missions, and the cultural schema of each
community. The Schoharie River Center
operates three EST programs in different areas,
all within the Mohawk River and/or Schoharie
Creek watershed. In Schenectady, the EST
program operates as an afterschool youth
development program targeting at-risk and inner
city youth, engaging them in water quality
monitoring of local streams and the Mohawk
River. Youth also participate in a variety of
environmentally based community service
activities and public education programs
designed to support them academically and
promote the values of stewardship and a greater
understanding of their (and their communities)
relationship to the natural world and the larger
environment. The Schoharie EST program, in
operation in Duanesburg since 2001, works with
youth from three counties (Schenectady,
Schoharie, and Montgomery) primarily studying
the lower Schoharie Creek and its tributaries as
well as the Normanskill. The first EST program
established by the SRC (a non-profit
organization) with the help of Mr. Kelly Nolan,
(Watershed Assessment Associates, LLC.), the
Schoharie EST program meets bi-weekly on
weekends year round, and involves youth ages
13 – 18 and their parents in a wide range of
freshwater monitoring and bio-assessment
study , outdoor recreation activities, community
archeology projects, and maple syrup making.
Youth in EST document their research both in
writing and through video and photography, and
present their research findings at local science
conferences such as the Clean Water Congress
(Hudson Basin River Watch) and at local
community festivals and school science fairs.
The program has also partnered with local
schools to develop field trip opportunities and
special programs for area youth to participate in
school and community based research
opportunities. The Manor kill EST program in
the Conesville –Gilboa area (in Schoharie
County and within the NYC Watershed) was
established by the Schoharie River Center in
2009, with grant funding from the Schoharie
County Youth Bureau, the United Way, and
NYC DEP Watershed Protection Fund. This
EST program is working closely with the local
school (Gilboa-Conesville School district), the
Town of Conesville, and the Schoharie County
SWCD office to implement specific aspects of
the county’s approved Manor kill Watershed
Management Plan. The focus of the program is
youth skills development and stewardship
education, integrating stream water quality
monitoring activities with riparian zone surveys,
invasive species removal (Knotweed) and native
species replanting projects with academic
support. Members from the three EST programs
do participate together periodically in specific
training and recreation activities that allow them
to meet together and learn about one another
their home waters. All three programs are
geographically within the same watershed, the
Mohawk River Basin (about 100 river miles
apart). However, the Manor kill is part of the
NYC Watershed due to the Gilboa Dam and
reservoir, which impounds the upper half of the
Schoharie Creek to provide drinking water to
New York City. Each EST program, (and the
youth who participate in them) although living in
separate communities, are linked together
through the experience of being in the same
watershed and the same watershed-monitoring
program.
Based on the success and continued growth of
the Schoharie/Mohawk EST programs we
believe that the EST model offers a blueprint for
other communities and organizations that may
want to initiate greater community outreach and
involvement their regional efforts and stream
management.
For more information about the Environmental
Study Team programs at the Schoharie River
Center, or to inquire about starting a new EST
program in your area. Contact John McKeeby,
Executive Director, Schoharie River Center, Inc.
2047 Burtonsville Road, Esperance, NY 12066,
or email at schoharierivercenter@juno.com.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
36
PROTECTING WATER QUALITY THROUGH A WATERSHED APPROACH
Kevin Millington
New York State Department of State
The Department of State encourages the
preparation of inter-municipal watershed
protection plans as a means to effectively
identify priorities, establish a consensus on
future actions, and guide the resources needed
for implementation. The Department has
extensive experience in this topic, and provides
grants from the Environrnental Protection Fund -
Local Waterfront Revitalization Program for the
preparation and implementation of such plans.
Addressing the complex issues affecting a
specific water body is most effectively
accomplished through inter-municipal efforts
based on a watershed eco-system approach.
Through both financial and technical resources,
the Department has fostered the preparation and
implementation of numerous watershed
protection plans across the State. Most recently,
a $370,270 grant from the Environmental
Protection Fund - Local Waterfront
Revitalization Program was awarded for the
preparation of a watershed plan for the Mohawk
River.
To further assist communities, the Department
recently completed a guidebook which describes
in detail the components and benefits of a inter-
municipal, watershed plan.
The Department of State’s Inter-municipal
Watershed Management Program provides
municipalities with professional expertise and
funding to develop and implement watershed
management plans to protect and restore water
quality and related resources. The Inter-
municipal Watershed Management Program
focuses on identifying connections between land
use and water quality to reach consensus on
actions to protect water resources while
facilitating economic development and guiding
growth to the most appropriate locations.
Department staff with backgrounds in the natural
sciences and local and regional planning work
closely with interested communities across the
State.
The Inter-municipal Watershed Management
Program enables communities to:
• Establish a mechanism for long-term
watershed management, often through the
creation of an inter-municipal watershed
organization;
• Describe and understand existing water
quality and watershed conditions, current
impairments and anticipated threats to
water quality, and recognize the key
problems and opportunities in the
watershed;
• Identify and describe priority actions
needed to address water quality
impairments or threats;
• Create an implementation strategy
identifying stakeholder roles and the
financial and institutional resources needed
to undertake these priorities;
• Develop a means to measure success,
track implementation, and monitor
performance; and
• Network with other communities, agencies
and organizations with experience in the
successful preparation and implementation
of watershed management plans.
To this mix, Department of State, as New York’s
coastal management and community planning
agency, brings its extensive experience in
creating practical responses to land and resource
management challenges - experience that has
shown the importance of inter-municipal and
inter-agency collaboration.
Benefits of Watershed Management - Clean
and plentiful waters are needed to support local
economies, provide recreational opportunities,
sustain fish and wildlife habitats, and enrich our
everyday experiences. New York State’s water
resources - rivers and streams; lakes and
reservoirs; estuaries; Great Lakes; and the
Atlantic Ocean and Long Island Sound - all
contribute to our quality of life. Planning on a
watershed scale allows communities to
effectively and comprehensively address water
quality issues throughout their watershed, while
balancing the need for economic growth and
development.
Watershed Definition - A watershed is a
geographic feature. It is the total area of land
draining to a body of water such as a stream,
A watershed is defined as the total area of land
draining to a body of water.
In: Cockburn, J.M.H. and Garver, J.I., Proceedings of the 2010 Mohawk Watershed Symposium,
Union College, Schenectady, NY, March 19, 2010
37
river, wetland, estuary, or aquifer. Watersheds
can range in size from a few acres that drain into
a small creek to a large basin that drains an entire
region into a major waterbody, such as Lake
Ontario. A watershed is not confined by
jurisdictional boundaries. Its boundaries are
determined by topography and on the nature of
how water moves. More often than not, a
watershed spans multiple jurisdictions. It is,
therefore, important that counties, towns,
villages and cities work together to address
shared water quality problems and to seek
available opportunities. By using the appropriate
geographic scale, a watershed management plan
can be developed that best meets the needs of
any community.
Department of State Intermunicipal Watershed
Management Plans The Department’s
approach to watershed planning has proven
highly successful throughout New York, from
Long Island to the Adirondacks, and from the
Hudson River Valley to the Great Lakes.
Watershed management plans guide
communities to identify critical actions needed to
protect and restore water quality, set watershed
priorities, and develop a strong and clear
implementation strategy for the future. Together
with municipal, State, and federal partners, the
Department has assisted in the development and
implementation of 37 watershed management
plans coveri